Publication

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1. Model Scaling in Smartphone GNSS-Aided Photogrammetry for Fragmentation Size Distribution EstimationZedrick Paul L. Tungol, Hisatoshi Toriya, Narihiro Owada, Itaru Kitahara, Fumiaki Inagaki, Mahdi Saadat, Hyong Doo Jang, Youhei KawamuraMINERALS 11 12 2021年12月 Fragmentation size distribution estimation is a critical process in mining operations that employ blasting. In this study, we aim to create a low-cost, efficient system for producing a scaled 3D model without the use of ground truth data, such as GCPs (Ground Control Points), for the purpose of improving fragmentation size distribution measurement using GNSS (Global Navigation Satellite System)-aided photogrammetry. However, the inherent error of GNSS data inhibits a straight-forward application in Structure-from-Motion (SfM). To overcome this, the study proposes that, by increasing the number of photos used in the SfM process, the scale error brought about by the GNSS error will proportionally decrease. Experiments indicated that constraining camera positions to locations, relative or otherwise, improved the accuracy of the generated 3D model. In further experiments, the results showed that the scale error decreased when more images from the same dataset were used. The proposed method is practical and easy to transport as it only requires a smartphone and, optionally, a separate camera. In conclusion, with some modifications to the workflow, technique, and equipment, a muckpile can be accurately recreated in scale in the digital world with the use of positional data.
2. Coupling NCA Dimensionality Reduction with Machine Learning in Multispectral Rock Classification ProblemsBrian Bino Sinaice, Narihiro Owada, Mahdi Saadat, Hisatoshi Toriya, Fumiaki Inagaki, Zibisani Bagai, Youhei KawamuraMINERALS 11 8 2021年08月 Though multitudes of industries depend on the mining industry for resources, this industry has taken hits in terms of declining mineral ore grades and its current use of traditional, time-consuming and computationally costly rock and mineral identification methods. Therefore, this paper proposes integrating Hyperspectral Imaging, Neighbourhood Component Analysis (NCA) and Machine Learning (ML) as a combined system that can identify rocks and minerals. Modestly put, hyperspectral imaging gathers electromagnetic signatures of the rocks in hundreds of spectral bands. However, this data suffers from what is termed the 'dimensionality curse', which led to our employment of NCA as a dimensionality reduction technique. NCA, in turn, highlights the most discriminant feature bands, number of which being dependent on the intended application(s) of this system. Our envisioned application is rock and mineral classification via unmanned aerial vehicle (UAV) drone technology. In this study, we performed a 204-hyperspectral to 5-band multispectral reduction, because current production drones are limited to five multispectral bands sensors. Based on these bands, we applied ML to identify and classify rocks, thereby proving our hypothesis, reducing computational costs, attaining an ML classification accuracy of 71%, and demonstrating the potential mining industry optimisations attainable through this integrated system.
3. Tourist Participation in the Preservation of World Heritage - A Study at in Cambodia -Fumiya Kimura, Yutaka Ito, Toshiya Matsui, Hidehiko Shishido, Itaru Kitahara, Youhei Kawamura, Atsuyuki MorishimaJOURNAL OF CULTURAL HERITAGE 50 163 - 170 2021年07月 World Heritage Sites (WHSs) face several problems, such as increased maintenance costs, difficulties in checking protection conditions, and graffiti destruction by tourists. Hence, constructing a new system that can effectively lighten the burden of maintenance expenditures is necessary. Presently, a new preservation system that leverages Information and Communication Technology, 3D Restoration Technology by photographic data collection, and artificial intelligence and that involves tourists' participation has been developed. This paper aims to introduce the new preservation system, investigate the possibility of tourists cooperating with the system free of charge, and introduce the details and results of a choice experiment conducted on tourists at Bayon Temple in Cambodia. Analysis results showed that approximately 50% of respondents would be willing to cooperate free of charge, and statistical significance for certain attributes and interactions. The analysis indicated that providing appropriate incentives to tourists who have specific individual characteristics would help promote the use of the preservation system. (c) 2021 Elsevier Masson SAS. All rights reserved.
4. Investigating asperity damage of natural rock joints in polycrystalline rocks under confining pressure using grain-based modelMahdi Saadat, Abbas Taheri, Youhei KawamuraCOMPUTERS AND GEOTECHNICS 135 104144 - 104144 2021年07月 [査読有り][通常論文]
    A cohesive grain-based model (GBM) was employed to investigate the asperity damage response of jointed Aue granite under confined compression. The cohesive GBM was able to characterise both inter- and intra-grain contacts in distinct element method (DEM). We calibrated the model against the laboratory data, including confined and unconfined compression tests as well as Brazilian tensile test of Aue granite. We generated synthetic Aue granite specimens, including three different rock joint profiles with various joint roughness coefficients (JRC) from smooth to very rough (i.e. 4.6, 10.2, and 17.5). We conducted confined compression tests on the synthetic specimens under 2, 5, 10, and 40 MPa of confining pressures. The numerical results revealed that at high confining pressure (i.e. 40 MPa), the rock joint profile had a negligible influence of the damage response of the specimen, and only contributed to the reduction of strength. For the other numerical experiments, the intensity of asperity damage caused by grain crushing was more pronounced when the confining pressure was high. We concluded that the cohesive GBM framework has the potential to be used as a virtual laboratory for investigating the shear behaviour of jointed granitic rocks, which is challenging to be studied in the laboratory.
5. Incorporating asperity strength into rock joint constitutive model for approximating asperity damage: An insight from DEM modellingMahdi Saadat, Abbas Taheri, Youhei KawamuraENGINEERING FRACTURE MECHANICS 248 107744 - 107744 2021年05月 [査読有り][通常論文]
    This paper presents a DEM experiment for developing a rock joint constitutive model that is able to consider lab-scale geometrical parameters of waviness and unevenness. We carried out a systematic parametric study using DEM framework to investigate the influence of asperity area and asperity angle on the peak shear strength and peak dilation angle. Based on the insights obtained from numerical outputs, we defined an asperity strength parameter that was incorporated into the failure criterion of the rock joint model. We defined an asperity damage function to characterise the degradation of asperity strength parameter. Besides, we developed a separate damage function to consider the deterioration of frictional components of rock joints. Also, we augmented the dilative response of the rock joint model by defining a new dilation predictor that mimics the normal displacement with respect to the progressive shear displacement of the rock joint. The damage function was linked to plastic displacement of rock joint in all damage functions. We compared the model outputs with the results of experimental direct shear tests conducted on natural rock joints and observed a good agreement.
6. Mutual superimposing of SAR and ground-level shooting images mediated by intermediate multi-altitude images.Hisatoshi Toriya, Narihiro Owada, Mahdi Saadat, Fumiaki Inagaki, Ashraf Dewan, Youhei Kawamura, Itaru KitaharaArray 12 100102 - 100102 2021年
7. Hazard mapping of ground subsidence in east area of Sapporo using frequency ratio model and GISTaeyoo Na, Youhei Kawamura, Seong-seung Kang, Shinji UtsukiGEOMATICS NATURAL HAZARDS & RISK 12 1 347 - 362 2021年01月01日 [査読有り][通常論文]
    As an earthquake occurred in Iburi subprefecture, Japan on September 2018, Sapporo has also been damaged by ground subsidence. Ground subsidence can occur in various area, especially in urban areas causing considerable damage to human lives and properties. Currently, ground subsidence is one of the most important problems all over the world. However, quantitative research about ground subsidence due to earthquake that particularly occurred in urban area was not well studied. To prevent and minimize critical damage caused by subsidence, this study aims to construct hazard map to predict susceptible subsidence place in East area of Sapporo, using geographic information system (GIS) and frequency ratio (FR) model. To determine major factors related to ground subsidence, spatial databases were constructed from geological map, slope data, land use map, borehole data, precipitation data, railroad and subway line data and earthquake information data. Weight of each factors were estimated by FR model to analyze degree of subsidence hazard and construct subsidence hazard map. Constructed subsidence susceptibility map was compared with reported actual ground subsidence area for verification and showed prediction accuracy of 85.17%. This result showed sufficient possibility for reliable susceptibility mapping of ground subsidence using GIS and FR model.
8. Automated Identification of Mineral Types and Grain Size Using Hyperspectral Imaging and Deep Learning for Mineral ProcessingNatsuo Okada, Yohei Maekawa, Narihiro Owada, Kazutoshi Haga, Atsushi Shibayama, Youhei KawamuraMINERALS 10 9 1 - 22 2020年09月 In mining operations, an ore is separated into its constituents through mineral processing methods, such as flotation. Identifying the type of minerals contained in the ore in advance aids greatly in performing faster and more efficient mineral processing. The human eye can recognize visual information in three wavelength regions: red, green, and blue. With hyperspectral imaging, high resolution spectral data that contains information from the visible light wavelength region to the near infrared region can be obtained. Using deep learning, the features of the hyperspectral data can be extracted and learned, and the spectral pattern that is unique to each mineral can be identified and analyzed. In this paper, we propose an automatic mineral identification system that can identify mineral types before the mineral processing stage by combining hyperspectral imaging and deep learning. By using this technique, it is possible to quickly identify the types of minerals contained in rocks using a non-destructive method. As a result of experimentation, the identification accuracy of the minerals that underwent deep learning on the red, green, and blue (RGB) image of the mineral was approximately 30%, while the result of the hyperspectral data analysis using deep learning identified the mineral species with a high accuracy of over 90%.
9. Enhancement of bitumen recovery from the oil sand in an alkaline solution using ultrasound irradiation and carbon dioxideHirokazu Okawa, Tomonao Saito, Shohei Yasuda, Youhei Kawamura, Takahiro Kato, Katsuyasu Sugawara, Tayfun BabadagliJAPANESE JOURNAL OF APPLIED PHYSICS 59 SK 2020年07月01日 [査読有り][通常論文]
    Herein, we demonstrated the enhancement of bitumen recovery from the oil sand in a concentrated alkaline solution using ultrasound irradiation and carbon dioxide. The alkaline solution allowed the separation of bitumen and sand; however, it was difficult to collect bitumen via aeration. CO exhibited a high contact angle for bitumen even at a high pH. Therefore, we attempted to use CO for bitumen recovery under ultrasound irradiation, increasing the number of collisions between bitumen and the CO bubbles; thus, the bitumen recovery ratio exhibited a high value of approximately 70% even at a low CO injection rate of 20 ml min 2 2 2 2 -1
10. Accurate Overlapping Method of Ultra-Long Interval Time-Lapse Images for World Heritage Site InvestigationHidehiko Shishido, Emi Kawasaki, Youhei Kawamura, Toshiya Matsui, Itaru KitaharaACM JOURNAL ON COMPUTING AND CULTURAL HERITAGE 13 2 10 - 18 2020年06月 In this article, a method is proposed to accurately overlap multiple high-quality images with different shooting positions and intervals by combining corresponding point information between images and 3D shape information. In the proposed method, the correct feature matching of images obtained by rendering the 3D model of the subject is used. In this research, the subjects were the pillars of the Angkor Thom Bayon Temple and the epilithic microorganisms adhering to and eroding their surfaces. Synthetic transformation of a homography utilizing the correct matches is employed to overlap the target images. When overlapping different background images using the conventional method, estimation of the homography matrix becomes difficult owing to incorrect matches; thus, high-quality overlapping images cannot be obtained. The objective of this research was to realize the overlapping image process even under conditions that cause incorrect feature matches, such as differences in background and illumination. In this study, the damaged parts of the pillar surfaces were visualized using the proposed method. Based on the results of an experiment comparing the proposed method with an existing state-of-the-art method, the effectiveness and higher accuracy of the proposed method were verified. The findings of this research contribute to Angkor Thom Bayon Temple preservation, including a preservation project that the present authors are organizing for this culturally and historically valuable United Nations Educational, Scientific and Cultural Organization World Heritage site.
11. 資源開発教育用VR 教材の開発およびVR教材を利用した授業の定量評価伊藤 豊, 竹内 誠人, 見上 柊人, 川村 洋平Journal of MMIJ 136 5 33 - 39 2020年05月31日 [査読有り][通常論文]
12. Development of 3D rock fragmentation measurement system using photogrammetryHyongdoo Jang, Itaru Kitahara, Youhei Kawamura, Yasunori Endo, Erkan Topal, Ryo Degawa, Samson MazaraINTERNATIONAL JOURNAL OF MINING RECLAMATION AND ENVIRONMENT 34 4 294 - 305 2020年04月 [査読有り][通常論文]
     Run-of-mine fragmentation is an important aspect of mine productivity optimisation, as it affects all mine-to-mill processes. In this study, a 3D rock fragmentation measurement (3DFM) system is proposed that can surmount the limitations of conventional 2D photo-based rock fragmentation measurement methods. To validate the proposed 3DFM performance, a laboratory-based comparison study was conducted using 100 randomly collected rock fragments. Conventional method exhibits relatively low and diffused results than the 3DFM. The proposed 3DFM can be considered as a new particle size distribution measurement method that should efficiently aid in improving mine productivity.
13. University Students' Preferences for Labour Conditions at a Mining Site: Evidence from Two Australian UniversitiesYutaka Ito, Shuto Mikami, Hyongdoo Jang, Abbas Taheri, Kenta Tanaka, Youhei KawamuraRESOURCES-BASEL 9 3 2020年03月01日 The mining industry makes up a large portion of the gross domestic product (GDP) in Australia, although securing human resources remains a problem in that field. The aim of this paper is to identify Australian university mining students' preferences, considering it as potential employees' preferences, for labour conditions at mining sites by means of a discrete choice experiment to promote efficient improvements in labour conditions in the mining industry. The data of 93 respondents analysed in this paper was collected by survey carried out in two universities in Australia. The result of the study showed that students have preferences on several factors such as wage, fatality rate, working position, commuting style, and company. Students having specific sociodemographic characters were found to show specific preferences on labour conditions. The results of this study indicate the potential average of appropriate monetary compensation for each factor.
14. Application of deep learning approaches in igneous rock hyperspectral imagingBrian Bino Sinaice, Youhei Kawamura, Jaewon Kim, Natsuo Okada, Itaru Kitahara, Hyongdoo JangSpringer Series in Geomechanics and Geoengineering 228 - 235 2020年 Hyperspectral imaging has been applied in remote sensing amongst other disciplines, success in these has triggered its extensive use. Hence, it comes as no surprise that we took advantage of this technology by conducting a study aimed at the spectral analysis of several igneous rocks, and to deduce the spectral signatures of each rock unit using neural networks. Through visual observations and comparisons of these spectral signatures, parameters such as band curvature(shape), tilt(position) and strength were used for lithological discrimination. Even with this said, there often exists similarities in rocks, which are rather difficult to differentiate by means of visual or graphical analysis. However, with numerous technologies making new waves in today’s era and artificial intelligence (AI) being at the forefront of these developments, it was best fitting to employ deep learning, often referred to as a subset of AI; to train/learn from these hyperspectral signatures with a goal aimed at classifying these rocks. Deep learning has networks such as the convolution neural network (CNN), which has algorithms that excel in feature representation from visual imagery; taking into account that the more data is fed into the training process and later used as a database for further training, the higher the future prediction accuracy. Gathered outcomes from the CNN show exceptionally high prediction accuracy capabilities of 96%; suggesting viable field and laboratory usage of these systems as a unit for mining and rock engineering applications.
15. Development of an underground in-situ stress monitoring system for mining safety using multi sensor cell and wi-fi direct technologyHajime Ikeda, Youhei Kawamura, Hyongdoo Jang, Nur Ellisha Binti Mokhtar, Jun Yokokura, Zedrick Paul L. TungolSpringer Series in Geomechanics and Geoengineering 236 - 244 2020年 The increasing global demand for minerals contributes to the necessity of mineral extraction at greater depths. However, the increase of rock in-situ stress with depth leads to higher risk and increasingly dangerous working conditions faced by mining workers. The presence of shafts, tunnels and other excavations necessary in mine expansions further increase the complexity of underground mines. This complexity of underground stress conditions increases the importance of monitoring and analysis of underground strata conditions, as early detection is crucial in the prevention of rock failure and the occurrence of fatal accidents. A better comprehension of the underground stress conditions in a mine is vital in considering mine design and supports that need to be installed. The development of an efficient monitoring system that can obtain and transmit data is necessary. This paper suggests the utilisation of a multi sensor cell that combines the functions of an accelerometer, gyroscope and a magnetometer, as well as strain gauge displacements to continuously measure the stress conditions of bedrock. The obtained data is then conveyed to the surface using a Wi-Fi Direct communication system and analysed to comprehend the changes in the underground stress conditions. The latter part of this paper also describes the experiments conducted to verify the ability of the proposed monitoring system.
16. An automated underground space monitoring and communication system based on wireless sensor networksMohammad Ali Moridi, Mostafa Sharifzadeh, Hyongdoo Jang, Youhei KawamuraSpringer Series in Geomechanics and Geoengineering 255 - 261 2020年 In the challenging environment and Cutting-edge technology in mining industry, reliable and effective communication is a high-stake issue, along with the objectives of safe and efficient underground mining operations. Automation through remote and automatic systems has delivered improvements in workplace health and safety for employees, operational management, energy and cost-effectiveness, and real-time response to events. In this context, Wireless Sensor Networks (WSNs) have been widely employed in underground monitoring and communication systems for the purpose of environmental monitoring, the positioning of workers and equipment, operational monitoring and communication system. Considering the capabilities of WSNs, a ZigBee network is adopted in this study. The aim of this study is to propose a reliable and effective monitoring and communication system in underground environments, using WSN nodes were developed to sense environmental attributes and texting emergency messages. A trigger action plan for monitored attributes above normal and threshold value limits is programmed in the surface GIS management server. The system will provide multi-users surface operation and 3D visualization for realistic understanding of underground environment and miners’ conditions.
17. Illumination of contributing parameters of uneven break in narrow vein mineHyongdoo Jang, Sina Taheri, Erkan Topal, Youhei KawamuraSpringer Series in Geomechanics and Geoengineering 457 - 466 2020年 One of the principal challenge facing the stope production in underground mining is the overbreak and underbreak (UB: uneven break). Although the UB features a critical economic fallout to the entire mining process, it is much inevitable and usually left as an unpredictable phenomenon in underground mines. The complex mechanism of UB must be examined to minimize the UB phenomenon. In this study, the contribution of ten primary UB causative parameters is scrutinized investigating a published UB prediction ANN model. The inputs (UB causative factors) contributions to the output (percentage of UB) of the ANN model were analyzed using Profile methodology (PM). The results PM revealed the essential importance of geological parameters to UB phenomenon as the calculated contributions of adjusted Q-rate (GAQ) and average horizontal to vertical stress ratio (GSK) are 20.48% and 18.12% respectively. Also, the trends of the other eight UB causative factors were investigated. The findings of this study can be used as a reference in stope design and reconciliation processes to maximize the productivity of the underground mine.
18. Clustering method of 3D point cloud of muck-pile based on connectivity of adjacent surfaceHidehiko Shishido, Zha Wanzhi, Hyongdoo Jang, Youhei Kawamura, Yoshinari Kameda, Itaru Kitahara2019 IEEE 8th Global Conference on Consumer Electronics, GCCE 2019 770 - 774 2019年10月 This paper proposes a method to measure the fragmentation distribution of a pile of rocks (muck-pile) using image-based 3D reconstruction. One of the most important aspects of mine-blasting is appropriate rock fragmentation to optimize the cost of the blasting operation. The conventional method of measuring fragmentation distribution is based on 2D image processing including segmentation of muck-pile regions into rock clusters. However, in the 2D method, the measurement accuracy is limited. To accurately measure rock fragmentation distribution, we reconstructed a 3D model of a muck-pile from multi-view images and segment the 3D model based on rock-features such as color, normal vector, distance and adjacent angles of surface planes. As a result, the size of each rock was calculated by fitting a bounding box. Based on experimental evaluations, it was confirmed that the accuracy of the proposed method is higher than that of previous methods.
19. An empirical approach of overbreak resistance factor for tunnel blastingHyongdoo Jang, Youhei Kawamura, Utsuki ShinjiTUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 92 2019年10月 [査読有り][通常論文]
     The assessment of overbreak is proposed by means of a novel empirical approach; the ‘overbreak resistance factor’ (ORF), to predict and manage the overbreak phenomenon in tunnel drill-and-blast operations. The proposed ORF is formulated by analysing the relationship between uncontrollable parameters of the overbreak phenomenon, i.e., geological parameters, and the corresponding overbreak measurements. Ninety data sets were collected from the Shin-Hakoishi Tunnel operation in Japan. Initially, an identical weight was applied to all geological parameters to generate ORF subfactors. The contribution of these subfactors to the measured overbreak was analysed through the use of five overbreak prediction artificial neuron network (ANN) models. A sensitivity analysis was conducted on the ANN models to reveal the contributions of input factors to measured overbreak. The discontinuities factors demonstrated the highest influence on overbreak with an overall sensitivity of 55.20%, whereas the strength factors, the weathering factors and the face condition factors showed less sensitivity, at 27.18%, 9.43%, and 8.18% respectively. The sensitivity analysis results were applied back to the initial unweighted data sets to generate a weighted record of subfactors. The ORF values showed a clear inverse proportional relation to the measured overbreak values, through linear regression analysis. Consequently, a five-step ORF prediction chart was developed, which can be directly applied to estimate overbreak in any drill-and-blast tunnel project.
20. アンコール遺跡群における地衣類の時系列変化画像の重畳宍戸, 英彦, 河﨑, 衣美, 川村, 洋平, 松井, 敏也, 北原, 格月刊考古学ジャーナル 730 29 - 33 ニューサイエンス社 2019年09月 [査読無し][通常論文]
21. ICを活用した予防保全のためのアンコール遺跡群バイヨン寺院を対象としたモニタリングシステムの開発池田, 啓, 川村, 洋平, 横倉, 潤, 宍戸, 英彦, 河﨑, 衣美, 伊藤, 豊, 北原 格, 丸太, 寛之, 里, 知樹, 松井, 敏也日本文化財科学会第36回大会発表要旨集 20 - 21 日本文化財科学会第36回事務局 2019年06月 [査読無し][通常論文]
22. Implementation and Verification of a Wi-Fi Ad Hoc Communication System in an Underground Mine EnvironmentH. Ikeda, Y. Kawamura, Z. P.L. Tungol, M. A. Moridi, H. JangJournal of Mining Science 55 3 505 - 514 2019年05月01日 Wireless sensor networks WI-Fi ad hoc have been proposed information transmission between data loggers and mobile station (smartphones). The wireless data transmission follows from an underground station to a worker’s smartphone and, then, after the worker has left the mine, to a data logger on the surface. The serviceability of this system was tested by measurement of communication quality indexes in various environments. The tests show that wireless communication between a stationary point and a mobile devise is possible at transfer speeds up to 2 MB/s with a packet error rate (PER) below 25% either at a maximum distance of 110 m in a straight path or at a distance of 20 m in case of a corner or turn of the path. The proposed system allows the transmission of 39.6–79.2 MB of monitoring data to a worker moving at 20 km/h.
23. Development of wireless sensor networks for underground communication and monitoring systems (the cases of underground mine environments)Mohammad Ali Moridi, Mostafa Sharifzadeh, Youhei Kawamura, Hyong Doo JangTUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 73 127 - 138 2018年03月 [査読有り][通常論文]
     The challenges of maintaining safe workplaces and improving operations and services in underground mines are unique. These have largely been mitigated by implementing new technology of wireless sensor networks (WSNs) in the last few years. Establishment and development of a reliable monitoring and communication network through such hostile environments are still major concerns. In this study, a more comprehensive monitoring and communication system for underground mine environments using ZigBee network are developed. To this regard, experiments with real systems and prototypes are applied. The controllable and uncontrollable parameters of both underground environment and network for the establishment of ZigBee network are also assessed. Then, a practical method to design a model of an underground mine monitoring and communication system is proposed. This model was verified by testing system functions and applications for example, temperature, humidity and illumination readings, text messaging, and controlling ventilation fans throughout an underground mine in Western Australia. The monitoring and communication systems operated successfully and it demonstrated the reliable outcomes of their function and application for underground mines.
24. Performance analysis of ZigBee network topologies for underground space monitoring and communication systemsMohammad Ali Moridi, Youhei Kawamura, Mostafa Sharifzadeh, Emmanuel Knox Chanda, Markus Wagner, Hirokazu OkawaTUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 71 201 - 209 2018年01月 [査読有り][通常論文]
     The advancement in tunnelling and underground space technologies and the need for large scale monitoring and communication systems for safe and efficient operations has triggered the era of wireless sensor networks (WSNs). The progress of WSNs have been associated with the innovation of sensor nodes with the more significant features of smaller size, more cost-effectiveness, lower latency and powerful antenna coverage. The sensor nodes arrangement in dense industrial WSNs is one of the crucial issues for a better quality of service and a reliable message transmission through the network. In this study, we investigate various sensor node arrangements of ZigBee networks for underground space monitoring and communication systems. The performance of ZigBee topologies are analysed in 12, 20, 30, 40 and 50-node scenarios for stationary node deployment in underground environments. The metrics used for the performance evaluation include throughput, packet delivery ratio (PDR), end-to-end delay, energy consumption and packet delivery security. The results evaluation confirms the mesh topology is prioritised in WSNs design considering higher throughput, packet delivery ratio and network security, while the cluster-tree topology is preferred in case of lower end-to-end delay and lower energy consumption. The analyses show that the mesh topology creates a more reliable monitoring and communication network with an adequate quality of service in underground spaces and tunnels. Therefore, greater end-to-end delay and energy consumption could not be major concerns for the mesh topology in underground mine applications based on the acceptable data latency and using mine power.
25. Time-Lapse Image Generation using Image-Based Modeling by CrowdsourcingHidehiko Shishido, Emi Kawasaki, Yutaka Ito, Youhei Kawamura, Toshiya Matsui, Itaru Kitahara2018 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) 3541 - 3542 2018年 [査読有り][通常論文]
     In recent years, the pillars of the World Heritage Angkor Thom Bayon temple have become a problem of deterioration due to moss breeding. We aim to generate an image to support observation of moss breeding on a pillar. Even under environment that prevent image processing, we can achieve accurate overlay processing by combining corresponding points between images and 3D shapes. In order to generate the timelapse image of the observation target, many accurate images of different capturing timings are necessary. We are going to use a lot of images collected by crowdsourcing for time lapse images. In this research, we use two crowdsourcing models with the »capturing image of the target region» and the »classification of the captured images» as the micro task. Therefore, image acquisition using crowdsourcing and generation of time lapse image are looped. Time lapse image will be more accurate by repeating this flow.
26. Comparison of Rock Fragmentation Measurement Systems with 3D System using Photogrammetry TechnologyKitahara, Itaru, Kawamura, Youhei, Topal, Erkan, Endo, Yasunori, Degawa, Ryo, Jang, HyongdooThe 2017 World Congress on Advances in Structural Engineering and Mechanics 2017年08月 [査読有り][通常論文]
27. Utilization of ultrasonic atomization for dust control in underground miningHirokazu Okawa, Kentaro Nishi, Youhei Kawamura, Takahiro Kato, Katsuyasu SugawaraJAPANESE JOURNAL OF APPLIED PHYSICS 56 7 2017年07月 [査読有り][通常論文]
     This study examined dust suppression using water particles generated by ultrasonic atomization (2.4 MHz) at low temperature (10 °C). Green tuff (4 μm), green tuff (6 μm), kaolin, and silica were used as dust samples. Even though ultrasonic atomization makes fine water particles, raising relative air humidity immediately was difficult at low temperature. However, remaining water particles that did not change to water vapor contributed to suppression of dust dispersion. Additionally, the effect of water vapor amount (absolute humidity) and water particles generated by ultrasonic atomization on the amount of dust dispersion was investigated using experimental data at temperatures of 10, 20, and 30 °C. Utilization of ultrasound atomization at low temperature has the advantages of low humidity increments in the working space and water particles remaining stable even with low relative air humidity.
28. Proactive Preservation of World Heritage by Crowdsourcing and 3D Reconstruction TechnologyHidehiko Shishido, Yutaka Ito, Youhei Kawamura, Toshiya Matsui, Atsuyuki Morishima, Itaru Kitahara2017 IEEE INTERNATIONAL CONFERENCE ON BIG DATA (BIG DATA) 2018-January 4426 - 4428 2017年07月01日 [査読有り][通常論文]
     Since over one million tourists annually visit the Angkor ruins, the effect on the buildings from the vibrations caused by these tourists is a huge problem for maintaining them. Such organisms as bryophytes, which adhere to the surface of the stones of the ruins, is another factor that damages them. Using crowdsourcing and 3D reconstruction technology, we are organizing a proactive preservation project for the Angkor Thom Bayon Temple, which is a world cultural heritage site. We evaluated its damaged parts and visualized the damaged state.
29. 粒度分布推定のための発破ずり３次元モデルの生成手法出川, 諒, 亀田, 能成, 川村, 洋平, Jang, Hyongdoo, 北原, 格電子情報通信学会 技術研究報告MVE 116 496 197 - 202 電子情報通信学会 2017年02月 [査読無し][通常論文]
30. Illumination of parameter contributions on uneven break phenomenon in underground stoping minesJang Hyongdoo, Topal Erkan, Kawamura YouheiINTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY 26 6 1095 - 1100 2016年11月01日 [査読有り][通常論文]
     One of the most serious conundrum facing the stope production in underground metalliferous mining is uneven break (UB: unplanned dilution and ore-loss). Although the UB has a huge economic fallout to the entire mining process, it is practically unavoidable due to the complex causing mechanism. In this study, the contribution of ten major UB causative parameters has been scrutinised based on a published UB predicting artificial neuron network (ANN) model to put UB under the engineering management. Two typical ANN sensitivity analysis methods, i.e., connection weight algorithm (CWA) and profile method (PM) have been applied. As a result of CWA and PM applications, adjusted Q rate (AQ) revealed as the most influential parameter to UB with contribution of 22.40% in CWA and 20.48% in PM respectively. The findings of this study can be used as an important reference in stope design, production, and reconciliation stages on underground stoping mine.
31. Development of a Landslide Observation System Using ZigBee Wireless Communication TechnologyY. Kawamura, H. Jang, K. Ohta, Y. InagakiGeotechnical Special Publication 2016-January 269 GSP 542 - 550 2016年 [査読有り][通常論文]
     Extensive area of Japan is subjected to threats of potential landslides as roughly 70 percent of Japan consists of a steep mountainous terrain and moreover numerous artificial hill slopes are developed in residential areas. While various types of structural counter measures have been developed and successfully implemented in Japan, significant numbers of areas remain unprotected. Hence, non-structural measures, such as hazard maps and early warning systems, are required to minimize risks. One of the key technologies of the early warning system is the automatic detection system for landslides. In this research, we are developing an automatic detection system for landslides using ZigBee wireless communication technology. A general ZigBee-compliant platform made by Hitachi Co. Ltd. was customized and used in the constructing the wireless landslide detection system. The developed system monitors various environmental data, such as 3-axes acceleration, temperature, humidity, and illumination intensity. It was verified that all measured parameters except humidity were measured properly at an actual slope site with the proposed system.
32. 3D Model Reconstruction of Rocks on a Slope for Simulating a Rock FallItaru Kitahra, Shogo Atsumi, Ryo Degawa, Youhei Kawamura, Hyongdoo Jang, Yuichi OhtaGeotechnical Special Publication 2016- 269 508 - 517 2016年 [査読有り][通常論文]
     For reducing damage of rock fall, it is important to estimate the route, leap height and velocity of the rock. Although research about estimation of falling motion of rocks are actively conducted, there are still unsolved issues, since rock fall is a complex phenomenon affected by position, size, or shape of rocks and angle of slope. This paper proposes a method of rock fall simulation using a 3D model of rock and slope reconstructed by merging multiple-view images. The proposed method requires only a mobile camera to generate a 3D model, so that more practical rock fall simulation can be realized. In addition, reconstructing textured 3D model makes inspectors visually confirm how the rock falls on the slope. Due to the difficulty capturing multiple images of both of rocks and a slope at a same time, rocks and a slope are individually captured, and then, they are merged in the post process. There are two problems to be solved for merging them accurately. One is the significant difference in their spatial resolution the other is the difference in the appearance caused by perspective projection. We conduct an experiments using multiple images of rocks and slopes captured at actual landslide site.
33. An Automated Sensing System for Steel Bridge Inspection Using GMR Sensor Array and Magnetic Wheels of Climbing RobotRui Wang, Youhei KawamuraJOURNAL OF SENSORS 2016 8121678 - 15 2016年 [査読有り][通常論文]
     Corrosion is one of the main causes of deterioration of steel bridges. It may cause metal loss and fatigue cracks in the steel components, which would lead to the collapse of steel bridges. This paper presents an automated sensing system to detect corrosion, crack, and other kinds of defects using a GMR (Giant Magnetoresistance) sensor array. Defects will change the relative permeability and electrical conductivity of the material. As a result, magnetic field density generated by ferromagnetic material and the magnetic wheels will be changed. The defects are able to be detected by using GMR sensor array to measure the changes of magnetic flux density. In this study, magnetic wheels are used not only as the adhesion device of the robot, but also as an excitation source to provide the exciting magnetic field for the sensing system. Furthermore, compared to the eddy current method and the MFL (magnetic flux leakage) method, this sensing system suppresses the noise from lift-off value fluctuation by measuring the vertical component of induced magnetic field that is perpendicular to the surface of the specimen in the corrosion inspection. Simulations and experimental results validated the feasibility of the system for the automated defect inspection.
34. Development of climbing robot for steel bridge inspectionRui Wang, Youhei KawamuraINDUSTRIAL ROBOT-THE INTERNATIONAL JOURNAL OF ROBOTICS RESEARCH AND APPLICATION 43 4 429 - 447 2016年 [査読有り][通常論文]
     Purpose - The purpose of this paper is to present a design of climbing robot with magnetic wheels which can move on the surface of steel bridge. The locomotion concept is based on adapted lightweight magnetic wheel units with relatively high attractive force and friction force. Design/methodology/approach - The robot has the main advantages of being compact (352 - 215 - 155 mm), lightweight (2.3 kg without battery) and simple mechanical structure. It is not only able to climb vertical walls and follow circumferential paths, but also able to pass complex obstacles such as bolts, steps, convex and concave corners with almost any inclination regarding gravity. By using a servo as a compliant joint, the wheel base can be changed to enable the robot to overcome convex corners. Findings - The experiment results show that the climbing robot has a good performance on locomotion, and it is successful in negotiating the complex obstacles. On the other hand, the limitations in locomotion of the robot are also presented. Originality/value - Compared with the past researches, the robot shows good performance on overcoming complex obstacles such as concave corners, convex corners, bolts and steps on the steel bridge. Magnetic wheel with the characterization of compact size and lightweight is able to provide bigger adhesion force and friction coefficient.
35. 浮き彫り保存のための強化剤で処理した砂岩のアコースティックエミッション跡見,洋祐, 松井,敏也, 川村 洋平アンコール遺跡調査報告書2014-2015 161 - 162 日本国政府アンコール遺跡救済チーム 2015年12月 [査読無し][通常論文]
36. A Multimedia Data Visualization Based on Ad Hoc Communication Networks and Its Application to Disaster ManagementYouhei Kawamura, Markus Wagner, Hyongdoo Jang, Hajime Nobuhara, Takeshi Shibuya, Itaru Kitahara, Ashraf M. Dewan, Bert VeenendaalISPRS INTERNATIONAL JOURNAL OF GEO-INFORMATION 4 4 2004 - 2018 2015年12月 [査読有り][通常論文]
     After massive earthquakes and other large-scale disasters, existing communication infrastructure may become unavailable and, therefore, it can be quite difficult for relief organizations to fully grasp the impact of the disaster on the affected region. Consequently, this will be the cause of delays to offer the strategic assistance, and to provide water and food, etc. In order to solve the problem of re-establishing communication infrastructure to allow for information gathering, we developed an ad hoc mobile communications network for disaster-struck areas using ZigBee. As the communication speed of ZigBee is low, we propose a problem-specific image compression method for the multimedia data visualization. By using the proposed method combined with GPS information, it is possible to quickly grasp the damage situation in the region. Through our communication experiments in Tsukuba City, Japan we confirm the effectiveness of our system as a disaster information gathering and management system.
37. Development of underground mine monitoring and communication system integrated ZigBee and GISMoridi Mohammad Ali, Kawamura Youhei, Sharifzadeh Mostafa, Chanda Emmanuel Knox, Wagner Markus, Jang Hyongdoo, Okawa HirokazuINTERNATIONAL JOURNAL OF MINING SCIENCE AND TECHNOLOGY 25 5 811 - 818 2015年09月01日 [査読有り][通常論文]
     An automated underground mine monitoring and communication system based on the integration of new technologies is introduced to promote safety and health, operational management and cost-effectiveness. The proposed system integration considering Wireless Sensor Network (WSN) assisted Geographic Information System (GIS) enables to monitor and control underground mining applications from surface office. Based on the capabilities of WSNs, ZigBee network is adapted for near real-time monitoring, ventilation system control and emergency communication in underground mine. ZigBee nodes were developed to sense environmental attributes such as temperature, humidity and gases concentration; switching ON and OFF ventilation fans; and texting emergency messages. A trigger action plan for monitored attributes above normal and threshold value limits is programmed in the surface GIS management server. It is designed to turn the auxiliary fans on remotely or automatically in orange condition and sending evacuation messages for underground miners in unsafe (red) condition. Multi-users operation and 3D visualisations are other successful achievements of the proposed system for the underground monitoring and communication.
38. Analysis of Radio Wave Propagation in an Urban Environment and its Application to Initial Disaster Response SupportYouhei Kawamura, Hyongdoo Jang, Markus Wagner, Hajime Nobuhara, Ashraf M. Dewan, Bert Veenendaal, Itaru KitaharaJOURNAL OF DISASTER RESEARCH 10 4 655 - 666 2015年08月01日 [査読有り][通常論文]
     When disasters strike, it is important to quickly collect and analyze disaster-related information immediately after the event. We have suggested ZigBee and geographic information systems (GIS) technologies to resolve these problems and provide an effective communications system. In this paper, a method for the rapid setup of short-range wireless networks infrastructure, which estimates the radio wave propagation and optimizes the positions of transmitters is proposed. Our estimation method is experimentally verified, and it combines ray-tracing with preliminarily obtained statistical attenuation information, which allows us to consider different types of the land and its elevation. Thus, we can determine the effective ranges for radio communication for each potential location in the actual environment. This information is then used in our optimization procedure to reduce the number of transmitters needed to establish connections.
39. 観光客に起因する振動の調査（第２報）－旧富岡製糸場 東置繭書における事例―跡見,洋祐, 松井,敏也, 川村,洋平日本文化財科学第32回大会研究発表要旨集 96 - 97 日本文化財科学会 2015年07月 [査読無し][通常論文]
40. Removal of arsenious acid from sulfuric acidic solution using ultrasound oxidation and goethiteHirokazu Okawa, Tomohiro Yoshikawa, Ryota Hosokawa, Shinji Hangui, Youhei Kawamura, Katsuyasu SugawaraJAPANESE JOURNAL OF APPLIED PHYSICS 54 7 2015年07月01日 [査読有り][通常論文]
     We investigated the properties of synthetic goethite for the adsorption of As from strongly acidic solutions in ambient atmosphere under ultrasound irradiation. The goethite was successfully synthesized from iron-containing sulfuric acidic solution (1271 ppm) using an autoclave apparatus for 1h at 0.12MPa and 121 °C. The ratio of the iron eluted from the synthetic goethite to the acidic solution was only 0.58% at pH 2.1. Ultrasound irradiation (200 kHz, 200 W) was applied to oxidize 10 ppm of As(III) to As(V) at pH 2.2 for 60 min under various atmospheric conditions. Remarkably, the oxidation ratio of As(III) to As(V) is quite high (89.7%) at pH 2.2 in ambient atmosphere and is close to those obtained for Ar (95.3%) and O2 (95.9%) atmospheres. The As(III) removal ratio reached 94.5% after 60 min of irradiation. Therefore, goethite is a promising material for As adsorption using ultrasound oxidation in the acidic region in ambient atmosphere.
41. Decision support system of unplanned dilution and ore-loss in underground stoping operations using a neuro-fuzzy systemHyongdoo Jang, Erkan Topal, Youhei KawamuraAPPLIED SOFT COMPUTING 32 1 - 12 2015年07月01日 [査読有り][通常論文]
     Abstract Unplanned dilution and ore-loss are the most critical challenges in underground stoping operations. These problems are the main cause behind a mine closure and directly influencing the productivity of the underground stope mining and the profitability of the entire operation. Despite being aware of the significance of unplanned dilution and ore-loss, prediction of these phenomena is still unexplained as they occur through complex mechanisms and causative factors. Current management practices primarily rely on similar stope reconciliation data and the intuition of expert mining engineers. In this study, an innovative unplanned dilution and ore-loss (uneven break: UB) management system is established using a neuro-fuzzy system. The aim of the proposed decision support system is to overcome the UB phenomenon in underground stope blasting which provides quantitative prediction of unplanned dilution and ore-loss with practical recommendations simultaneously. To achieve the method proposed, an uneven break (UB) prediction system was developed by an artificial neural network (ANN) considering 1076 datasets covering 10 major UB causative factors collected from three underground stoping mines in Western Australia. In succession, the UB consultation system was established via a fuzzy expert system (FES) in reference to surveyed results of fifteen underground-mining experts. The UB prediction and consultation system were combined as one concurrent neuro-fuzzy system that is named the 'uneven break optimiser'. Because the current UB prediction systems in investigated mines were highly unsatisfactory with correlation coefficient (R) of 0.088 and limited to only unplanned dilution, the performance of the proposed UB prediction system (R of 0.719) is a remarkable achievement. The uneven break optimiser can be directly employed to improve underground stoping production, and this tool will be beneficial not only for underground stope planning and design but also for production management.
42. Unplanned dilution and ore loss prediction in longhole stoping mines via multiple regression and artificial neural network analysesH. Jang, E. Topal, Y. KawamuraJOURNAL OF THE SOUTHERN AFRICAN INSTITUTE OF MINING AND METALLURGY 115 5 449 - 456 2015年05月 [査読有り][通常論文]
     Unplanned dilution and ore loss directly influence not only the productivity of underground stopes, but also the profitability of the entire mining process. Stope dilution is a result of complex interactions between a number of factors, and cannot be predicted prior to mining. In this study, unplanned dilution and ore loss prediction models were established using multiple linear and nonlinear regression analysis (MLRA and MNRA), as well as an artificial neural network (ANN) method based on 1067 datasets with ten causative factors from three underground longhole stoping mines in Western Australia. Models were established for individual mines, as well as a general model that includes all of the mine data-sets. The correlation coefficient (R) was used to evaluate the methods, and the values for MLRA, MNRA, and ANN compared with the general model were 0.419, 0.438, and 0.719, respectively. Considering that the current unplanned dilution and ore loss prediction for the mines investigated yielded an R of 0.088, the ANN model results are noteworthy. The proposed ANN model can be used directly as a practical tool to predict unplanned dilution and ore loss in mines, which will not only enhance productivity, but will also be beneficial for stope planning and design.
43. Unplanned dilution and ore loss prediction in longhole stoping mines via multiple regression and artificial neural network analysesH. Jang, E. Topal, Y. KawamuraJournal of the Southern African Institute of Mining and Metallurgy 115 5 449 - 456 2015年 [査読有り][通常論文]
     Unplanned dilution and ore loss directly influence not only the productivity of underground stopes, but also the profitability of the entire mining process. Stope dilution is a result of complex interactions between a number of factors, and cannot be predicted prior to mining. In this study, unplanned dilution and ore loss prediction models were established using multiple linear and nonlinear regression analysis (MLRA and MNRA), as well as an artificial neural network (ANN) method based on 1067 datasets with ten causative factors from three underground longhole stoping mines in Western Australia. Models were established for individual mines, as well as a general model that includes all of the mine data-sets. The correlation coefficient (R) was used to evaluate the methods, and the values for MLRA, MNRA, and ANN compared with the general model were 0.419, 0.438, and 0.719, respectively. Considering that the current unplanned dilution and ore loss prediction for the mines investigated yielded an R of 0.088, the ANN model results are noteworthy. The proposed ANN model can be used directly as a practical tool to predict unplanned dilution and ore loss in mines, which will not only enhance productivity, but will also be beneficial for stope planning and design.
44. 振動解析による石造遺跡の予防診断法の開発Ⅱ－凍結融解による破壊分析－跡見,洋祐, 松井,敏也, 川村,洋平日本文化財科学会第31回大会研究発表要旨集 86 - 87 日本文化財化学会 2014年07月 [査読無し][通常論文]
45. An investigation of underground monitoring and communication system based on radio waves attenuation using ZigBeeMohammad Ali Moridi, Youhei Kawamura, Mostafa Sharifzadeh, Emmanuel Knox Chanda, Hyongdoo JangTUNNELLING AND UNDERGROUND SPACE TECHNOLOGY 43 362 - 369 2014年07月 [査読有り][通常論文]
     In the challenging environment and changing topology of a mine, reliable and effective communication is a high-stake issue along with the objectives of safe and efficient mining operations. Automation by remote and automatic systems have improved workplace health and safety for employees, cost-effectiveness, management of technical problems, energy saving, real-time response to events. In response to these challenges, wireless sensor networks (WSNs) have been widely employed in underground monitoring and communication systems for the purpose of environmental monitoring, positioning of workers and equipment, operational monitoring and communication system. Considering the capabilities of WSNs, ZigBee network is adapted. In this study, common WSNs are evaluated for application in underground mines and demonstrated why ZigBee network performance is suitable for such environments. ZigBee radio waves attenuation is investigated to evaluate stable communication range between ZigBee nodes at straight and curved tunnels in a real mine scenario. Moreover, experimental measurements of ZigBee radio waves attenuation are validated by simulation results. Based on the analysis of the experimental and simulation results, the effective factors on the radio waves attenuation in the junctions, curvatures and fields near and far from the source are assessed. Finally, stable wireless communication ranges between developed ZigBee nodes in the underground Angas Zinc Mine is concluded 100. m and 70. m for straight and curved tunnels, respectively. The development of ZigBee network application compared to other WSNs in underground mines is also approved. © 2014 Elsevier Ltd.
46. Using GIS to develop a mobile communications network for disaster-damaged areasYouhei Kawamura, Ashraf M. Dewan, Bert Veenendaal, Masahiro Hayashi, Takeshi Shibuya, Itaru Kitahara, Hajime Nobuhara, Kento IshiiInternational Journal of Digital Earth 7 4 279 - 293 2014年04月 [査読有り][通常論文]
     Communications network damage resulting from a large disaster causes difficulties in the ability to rapidly understand the current situation and thus make appropriate decisions towards mitigating problems, such as where to send and dispense emergency supplies. The research outlined in this paper focuses on the rapid construction of a network after a disaster occurs. This study suggests ZigBee and geographic information systems (GIS) technologies to resolve these problems and provide an effective communication system. The experimental results of the ZigBee network system are presented, examples are provided of the mapping and analysis undertaken using GIS for the disaster-stricken area of Tsukuba City, Japan, and the communications node arrangements are determined for this region. These results demonstrate the effectiveness of establishing such a communications system for supporting efforts to relieve disaster-damaged areas. © 2013 © 2013 Taylor & Francis.
47. 直達音と地面反射音を利用する少素子ジオフォンアレイによる土中音源位置測定川岸,卓司, 善甫,啓一, 水谷,孝一, 若槻,尚斗, 川村,洋平土木学会論文集F3（土木情報学） 69 2 I_130 - I_138 Japan Society of Civil Engineers 2014年03月 [査読有り][通常論文]
     本稿は土中で発生する音源の位置測定法に関するものである．提案手法では，直達音だけではなく，地表面からの反射音も利用することで測定精度の向上を図っている．地表面で起こる反射音を利用するために，鉛直方向に一対の素子を配置した杭状のジオフォンを用いている．杭状ジオフォンアレイを2本（素子数：4）用いた評価実験の結果，位置推定精度は直達音のみを使用する従来手法と比べ3.42倍と向上することがわかった．また，ジオフォンアレイの配置や構成する素子のずれが音源位置の推定に与える影響を実規模シミュレーションにより実験し，提案手法の位置推定精度は従来手法に比べ最大で14.6倍に向上できることを確認した．以上より，従来手法に比べ高精度の音源位置測定が可能であることが示された．
48. Development of underground mine communication and monitoring systems by using ZigBee technologyY. Kawamura, M. A. Moridi, M. Sharifzadeh, H. JangISRM International Symposium - 8th Asian Rock Mechanics Symposium, ARMS 2014 1411 - 1420 2014年 Data transfer and communication systems are first priority for further development of geotechnical monitoring. This paper describes a Wireless Sensor Network (WSN) for communication and monitoring systems based on ZigBee technology in underground mines. Wireless sensor networks (WSNs) have been widely employed in industries and the military with multiple applications to monitor environment, track target and telecommunicate data. Recently, WSNs have also been used for communication and monitoring systems in underground mines. In this study, a proposed WSN system of ZigBee network as one of the WSNs is investigated in underground mines regarding communication and monitoring systems to resolve operational challenges such as safety and gathering geotechnical information. Developed ZigBee wireless network system was installed in Paddington Gold Underground Mine (managed by Norton Gold Fields Limited). In this research, the intensity of received signal strength indication (RSSI) between wireless nodes within ZigBee network was investigated. Also, the optimal arrangement of ZigBee wireless nodes on the basis of radio wave attenuation and possibility of stable wireless communications which will be used for gathering some significant geotechnical information such as seismic, deformation and pressure were investigated. The experimental results indicate that a secure and stable ZigBee wireless network can be developed to overcome mentioned operational challenges in underground mining. It is obvious that this proposed system helps further progress in rock mechanics and geotechnical fields.
49. Illustrating quality of life (QOL)Ashraf M. Dewan, Kamrun Nahar, Yohei KawamuraDhaka Megacity: Geospatial Perspectives on Urbanisation, Environment and Health 239 - 256 2014年01月01日 The objective of this chapter is to develop a quality of life (QOL) index at community level in the Dhaka City Corporation (DCC) area, which could describe the spatial patterns of QOL. Using remote sensing, census and other spatial data, a factor analysis was carried out to develop the different dimensions of QOL. Three principal factors were extracted from the analysis: environmental, economic and demographic. These three factors were then combined in a Geographic Information Systems (GIS) environment to construct a synthetic QOL for the study area. The results were subsequently validated using regression analysis, which revealed a better prediction of QOL based on environmental and socioeconomic variables. Interestingly, only a small portion of the population (1.4 %) in the study area was shown to have good QOL. As higher urban growth driven by rapid rural-urban migration is expected in Dhaka in the coming years, this study will be of substantial help for urban planners and policymakers in formulating related policies to ensure a better living environment for its inhabitants.
50. A Magnetic Climbing Robot for Steel Bridge InspectionRui Wang, Youhei Kawamura2014 11TH WORLD CONGRESS ON INTELLIGENT CONTROL AND AUTOMATION (WCICA) 2015-March March 3303 - 3308 2014年 [査読有り][通常論文]
     Corrosion can cause section loss or cracks in the steel members which is one of the most important causes of deterioration of steel bridges. For some critical components of a steel bridge, it is fatal and could even cause the collapse of the whole bridge. Nowadays the most common approach to steel bridge inspection is visual inspection by inspectors with inspection trucks. This paper mainly presents a climbing robot with magnetic wheels which can move on the surface of steel bridge. Experiment results shows that the climbing robot can move on the steel bridge freely without disrupting traffic to reduce the risks to the inspectors.
51. 少数ハイドロフォンアレイを用いる船舶スクリュー軸振れ検出(ポスターセッション)川岸,卓司, 善甫,啓一, 水谷,孝一, 若槻,尚斗, 海老原,格, 川村,洋平超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 34 357 - 358 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2013年11月 [査読無し][通常論文]
52. 地面反射を利用した土中の音源位置推定川岸,卓司, 善甫,啓一, 水谷,孝一, 若槻,尚斗, 川村,洋平土木学会, 2013年度土木情報学シンポジウム講演集 38 12 39 - 40 2013年09月 [査読無し][通常論文]
53. A6 オイルサンドからのビチューメン分離回収における超音波利用の検討(口頭発表)大川 浩一, 斉藤 知直, 菅原 勝康, 川村 洋平, Babadagli Tayfunソノケミストリー討論会講演論文集 22 11 - 12 日本ソノケミストリー学会 2013年 20% of Canada's oil sand is located on the surface of the ground. These oil sands are taken by means of open-pit mining. Oil sands contain about 10% bitumen. Bitumen is used as fuel energy, and it is necessary to separate bitumen from oil sand at high efficiency. Main industrial processes to separate bitumen from oil sand are treatments using hot water and steam in rotating drums. These treatments consist of two processes. The first is the bitumen separation from oil sand and the second is the bitumen flotation from aqueous solution to the solution surface. In this study, the role of high concentrated H_2O_2 to recover bitumen during sonication was investigated. Furthermore, we investigated the optimal combination of ultrasound and gases to improve the separation efficiency and the yield of bitumen from oil sand in the hot water process.
54. Front edge location estimation for flexion axis using length meter with accelerometer and gyroscopeSatoki Ogiso, Koichi Mizutani, Naoto Wakatsuki, Youhei Kawamura2013 IEEE 2nd Global Conference on Consumer Electronics, GCCE 2013 74 - 77 2013年 [査読有り][通常論文]
     Front edge location estimation for flexion axis has been demanded in several fields such as civil engineering or construction. Recently, there are several methods to achieve front edge location estimation using gyroscope. However, these methods require such as fiber optic gyroscope to reduce the effect of the drift. Therefore, front edge location estimation using low-cost type of sensors is still demanded. In this paper, the front edge location estimation method for flexion axis using a triaxial gyroscope, accelerometer and a length meter was proposed, to achieve drift-free location estimation by low cost sensors. The performance of the proposed method was evaluated using reduced model. From the experiments, the major cause of the error (the drift of the gyroscope) was found to be reduced to 2/3 to 1/2 compared to the previous method, and the estimation error could be minimized within 4%. © 2013 IEEE.
55. Investigation of Thermal Conductivity and Heat Characteristics of Oil Sands Using Ultrasound Irradiation for Shortening the Preheating TimeShingo Kamagata, Youhei Kawamura, Hirokazu Okawa, Koichi MizutaniJAPANESE JOURNAL OF APPLIED PHYSICS 51 7 07GE03  2012年07月 [査読有り][通常論文]
     Oil sands are attractive as an energy resource. Bitumen, which is found in oil sands, has high viscosity, so that it does not flow. Most oil sands are underground and are developed with a method called steam-assisted gravity drainage (SAGD). Hot steam is injected underground to fluidize bitumen and promote its recovery. However, the preheating time is too long. One way of reducing running costs is by shortening the preheating time. Previous studies have found that bitumen can be extracted from oil sands efficiently by applying ultrasonic irradiation, but SAGD was not applied directly in these cases. Thus, the purpose of this study is to apply ultrasonic irradiation to SAGD, thereby shortening the preheating time of oil sands. As a model experiment for SAGD, heat transfer experiments in a sand layer made with Toyoura sand and silicone oil were conducted and the thermal effect with ultrasound was investigated. © 2012 The Japan Society of Applied Physics.
56. Influence of Air Humidity and Water Particles on Dust Control Using Ultrasonic AtomizationHirokazu Okawa, Kentaro Nishi, Dai Shindo, Youhei KawamuraJAPANESE JOURNAL OF APPLIED PHYSICS 51 7 07GE06  2012年07月 [査読有り][通常論文]
     The influence of air humidity and water particles on dust control was examined using ultrasonic atomization at 2.4 MHz, an acrylic box (61 L), and four types of ore dust samples: green tuff (4 μm), green tuff (6 μm), kaolin, and silica. It was clearly demonstrated that ultrasonic atomization was effective in raising humidity rapidly. However, at high relative air humidity, the water particles remained stable in the box without changing to water vapor. Ultrasonic atomization was applied to suppress dust dispersion and 40-95% dust reduction was achieved at 83% relative air humidity. Dust dispersion was more effective with ultrasonic atomization than without. © 2012 The Japan Society of Applied Physics.
57. Emergency management withZigBeeand GISYouhei Kawamura, Bert Veenendaal, Ashraf M. Dewan, Masahiro Hayashi, Itaru Kitahara, Hajime Nobuhara, Kento IshiiISCIIA 2012 - 5th International Symposium on Computational Intelligence and Industrial Applications 2012年 Communications network damage resulting from a large disaster causes difficulties in the ability to rapidly understand the current situation and thus make appropriate decisions toward mitigating problems. This research focuses on the rapid construction of a network after a disaster occurs. This study suggests ZigBee and GIS technologies to resolve these problems and provide an effective communications system. This paper provides ground design of the emergency management system with ZigBee network and GIS technologies. In this paper, it was demonstrated the effectiveness of establishing such a communications system for supporting efforts to relieve disaster-damaged areas.
58. Development of digbot for monitoring the underground environmentMasahiro Hayashi, Toshiyuki Miyachi, Youhei Kawamura, Kazutoshi Murakami, Yuichi Kato, Hiroshi MochiyamaISCIIA 2012 - 5th International Symposium on Computational Intelligence and Industrial Applications 2012年 A digging robot named "DigBot" has been developed by our laboratory for monitoring the underground environment and exploring the lunar surface. The purpose of this research is to develop the robot which can dig soil and sand automatically. When we build the building or structure, ground research is indispensable to know that if the ground can hold the building. In addition, conceivable application of DigBot is investigation of geological condition and ground pollution after disaster. Standard penetration test and Swedish weight sounding test are known as the general way of ground research and are frequently used. But these methods have faults. For example, high costs or large scale. In this proceeding, first, concept of DigBot is shown. As a basic research of developing DigBot, Contra-rotating drill is developed and made for trial purpose. And then digging experiment is carried out for verifying effectiveness through the Contra-rotating drill. It was proved that DigBot possess incomparably more power than ever before. This research suggest the way of solving faults by using the robot which can dig underground and research underground information.
59. Efficient construction ofwireless personal area networks for disaster controlSeiji Yasunobu, Hajime Nobuhara, Yohei KawamuraISCIIA 2012 - 5th International Symposium on Computational Intelligence and Industrial Applications 2012年 Japan and Indonesia are the earthquake occurrence countries where located in the circum-Pacific volcanic zone. Researches on disaster recovery management have been important issues for both countries. Our research proposes a Disaster Recovery Management system based on the proposed low cost short-distance wireless (ZigBee) communication network and mobile phones. If every person in the disaster area is connected to this network, then the information of the position, injured person, died person, and lost person can be identified quickly. The information is processed using our soft computing method to generate a comprehensive recovery and mitigation plan. Then, the government and the rescue team can use this recovery and mitigation plan for disaster management. Also, civilian organizations can develop own rescue projects based on the proposed networks. This can shorten time in the disaster management process therefore the number of victims can be reduced.
60. 2Pa4-13 超音波霧化を利用した湿度調整とその防塵特性(ポスターセッション)大川, 浩一, 西, 健太郎, 進藤, 大, 川村, 洋平超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 0 32 133 - 134 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2011年11月 [査読無し][通常論文]
61. A Method for Estimating the Location of the Drill-Bit During Horizontal Directional Drilling Using a Giant-Magnetostrictive VibratorJunpei Tamura, Youhei Kawamura, Hidemi Mochiji, Naoto Sasaki, Koichi Mizutani, Hirokazu OkawaJapanese Journal of Applied Physics 50 07HC15-1 - 07HC12-6 2011年07月 [査読有り][通常論文]
62. A Method for Estimating the Location of the Drill-Bit During Horizontal Directional Drilling Using a Giant-Magnetostrictive VibratorJunpei Tamura, Youhei Kawamura, Hidemi Mochiji, Naoto Sasaki, Koichi Mizutani, Hirokazu OkawaJAPANESE JOURNAL OF APPLIED PHYSICS 50 7 2011年07月 [査読有り][通常論文]
     Horizontal directional drilling (HDD) is a commonly used method for laying pipelines that avoids the need to make an open cut. However, the location of the drill-bit underground must be known at all times when using this method. As conventional electromagnetic wave-based methods are known to have several problems, for example buildings in the line of construction, the moisture content of the ground and the presence of steel towers near the construction site. Herein we suggest a new method based on the propagation of elastic waves in the ground. Thus, measurement of the elastic waves generated by a giant-magnetostrictive vibrator by sensors set on the ground allows us to obtain the differences in arrival time of this wave at each sensor by applying a cross-correlation analysis to the waveforms detected. Finally, an approximate three-dimensional (3D) location method based on these differences was designed. © 2011 The Japan Society of Applied Physics.
63. Recovery of Bitumen from Oil Sand by Sonication in Aqueous Hydrogen PeroxideHirokazu Okawa, Tomonao Saito, Ryota Hosokawa, Takashi Nakamura, Youhei Kawamura, Shinobu KodaJAPANESE JOURNAL OF APPLIED PHYSICS 50 7 2011年07月 [査読有り][通常論文]
     The surface of bitumen is hydrophobic; therefore, floatation separation using gas flow into the solution was considered an effective recovery mechanism of bitumen from oil sand. Low (28 kHz) and high (200 kHz) frequency sonication combined with floatation separation at 85°C were investigated to assess the effects of different ultrasound frequencies on the recovery rate and purity of bitumen from oil sand. Hydrogen peroxide was also used as a frothing agent. The role of highly concentrated H O (>100ppm) to recover bitumen during sonication was investigated. Hydrogen peroxide formed a bubble around the bitumen, which made it rise more easily to the solution surface during sonication. The result showed a good recovery rate of bitumen. 28 kHz sonication combined with H O was a more appropriate method than that of 200 kHz to recover bitumen in a short time because of its strong stripping action caused by a strong jet flow. © 2011 The Japan Society of Applied Physics. 2 2 2 2
64. Sonication enables effective iron leaching from green tuff at low temperatureTakashi Nakamura, Hirokazu Okawa, Youhei Kawamura, Katsuyasu SugawaraJapanese Journal of Applied Physics 50 7 PART 2 2011年07月 [査読有り][通常論文]
     Ultrasound irradiation (28 and 200 kHz) was applied to iron leaching from green tuff into a low temperature solution (20°C) using oxalic acid. Ultrasound irradiation increased the amount of iron leached from the green tuff and was greater than that leached by stirring. It is thought that the jet flow caused by the collapse of cavities during ultrasound irradiation prevents and strips the deposits of iron oxalate from the green tuff particles. The extraction of iron at 28 kHz displayed better performance than that at 200 kHz for three reasons. The first is that the jet flow generated by cavitation bubble collapse at 28 kHz is thought to be stronger than that at 200 kHz. The second is that the crushing action of ultrasound irradiation at 28 kHz is greater than that at 200 kHz. The third is that 200 kHz irradiation generates OH radicals, which prevents the generation of FeH(C O ) and oxidizes FeH(C O ) to Fe(C O ), creating a cover layer on the surface of the stone. Thus, to leach iron from the ore, it is effective to use ultrasound irradiation at 28 kHz, which prevents the creation of radicals and breaks down the grain size. © 2011 The Japan Society of Applied Physics. 2 4 2 4 2 4 + +
65. Sonication Enables Effective Iron Leaching from Green Tuff at Low TemperatureTakashi Nakamura, Hirokazu Okawa, Youhei Kawamura, Katsuyasu SugawaraJAPANESE JOURNAL OF APPLIED PHYSICS 50 7 07HE16 - 07HE16-4 2011年07月 [査読有り][通常論文]
     Ultrasound irradiation (28 and 200 kHz) was applied to iron leaching from green tuff into a low temperature solution (20 degrees C) using oxalic acid. Ultrasound irradiation increased the amount of iron leached from the green tuff and was greater than that leached by stirring. It is thought that the jet flow caused by the collapse of cavities during ultrasound irradiation prevents and strips the deposits of iron oxalate from the green tuff particles. The extraction of iron at 28 kHz displayed better performance than that at 200 kHz for three reasons. The first is that the jet flow generated by cavitation bubble collapse at 28 kHz is thought to be stronger than that at 200 kHz. The second is that the crushing action of ultrasound irradiation at 28 kHz is greater than that at 200 kHz. The third is that 200 kHz irradiation generates OH radicals, which prevents the generation of FeH(C(2)O(4))(+) and oxidizes FeH(C(2)O(4))(+) to Fe(C(2)O(4)), creating a cover layer on the surface of the stone. Thus, to leach iron from the ore, it is effective to use ultrasound irradiation at 28 kHz, which prevents the creation of radicals and breaks down the grain size. (C) 2011 The Japan Society of Applied Physics
66. 超磁歪振動子を利用した極浅層における地中映像化システムに関する研究蒲原, 章裕, 川村, 洋平, 鎌形, 真伍, 大川, 浩一Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan 127 4 182 - 188 社団法人 資源・素材学会 2011年03月 [査読有り][通常論文]
     Recently, Water and gas pipes are developed frequently because of the increased urban population. When the underground piping is constructed, drawings and signs are needed to drill the ground. However, underground pipings and other buried objects are often buried in different locationscompared with drawings. Underground pipings, the rock and the gravel interfere with construction. It is necessary to avoid this situation. To determine the construction of underground pipes, the non-destructive imaging method previously detects the pipe inside the ground. This paper describes a system of ultrashallow underground imaging method using seismic reflection and seismic giant magnetostrictive transducer. We apply a surface wave analysis using a giant magnetostrictive transducer. We improve the accuracy of P wave velocity. For the high-efficiency setup and the underground imaging succeed. This system combines ultrashallow seismic reflection and the ultra-magnetostrictive transducer. It provides the practical system.
67. ホール素子を用いる高圧粘度計の開発安藤 寛, 佐々木 久郎, 川村 洋平, 大川 浩一, 菅井 裕一石油学会 年会・秋季大会講演要旨集 2011 103 - 103 公益社団法人 石油学会 2011年 高圧条件下において粘度を計測する手法は、大掛かりで非常にコストを要するものであった。本研究において、このような高圧条件下においても、簡便に粘度を計測できる手法を開発した。磁石の磁場をホール素子で計測することにより、流体中における磁石の落下運動を非接触で計測し、落体法を用いて流体の粘度を決定した。この計測手法を用いることで、圧力容器など高圧条件である容器内においても、機密性を保った流体の粘度計測をすることができる。
68. Solid-liquid separation by sonochemistry: A new approach for the separation of mineral suspensionsTakashi Nakamura, Hirokazu Okawa, Youhei Kawamura, Katsuyasu SugawaraULTRASONICS SONOCHEMISTRY 18 1 85 - 91 2011年01月 [査読有り][通常論文]
     The effect of sonochemistry to acidify solutions was applied for the solid-liquid separation of three kinds of mineral suspensions. At first, the relationship was measured between zeta-potential and pH in these suspensions to find pH levels correspondent to the isoelectric points. Then sonication (200 kHz or 28 kHz) was applied to adjust pH to the isoelectric points and separated particles from solutions by still-standing and spontaneous precipitation. Compared to the conventional methods using filters and chemical agents, the advantage of this sonochemical separation is two-fold. First, it does not require the maintenance of filters. Second, separated particles are easy to use since they are not mixed with pH adjusters and chemical flocculants. Isoelectric zone (ion strength 0.01, concentration 0.001 wt.%) of green tuff, andesite and titanium dioxide suspensions tested in this study were pH 1.1-3.7, 0.8-3.4, 2.7-5.7, respectively. The sonication of green tuff and andesite suspensions at 200 kHz changed the pH to the isoelectric zone despite the pH buffering effect of eluted alkali earth metals, and successfully precipitated the particles. On the contrary, the sonication of these suspensions at 28 kHz failed to adjust pH to the isoelectric zone, and the particles did not precipitate. In addition, the degradation of particles was observed in the SEM photographs of particles sonicated at 28 kHz, whereas no significant change was detected in particles sonicated at 200 kHz. Thus, it is concluded that the optimal frequency is about 200 kHz because its strong chemical effect can easily adjust the pH while its relatively weak physical effect prevents the degradation of particles. © 2010 Elsevier B.V.
69. 3Pb2-6 模擬地盤を用いた超磁歪振動子によるドリルビットの位置推定手法の検討(ポスターセッション)田村 潤平, 川村 洋平, 持地 英実, 佐々木 直人, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 32 32 477 - 478 特定非営利活動法人 超音波エレクトロニクス協会 2011年 [査読無し][通常論文]
70. 3Pa4-1 オイルサンド予熱手法への20kHz帯超音波の適用に関する基礎研究(ポスターセッション)鎌形 真伍, 川村 洋平, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 32 32 371 - 372 特定非営利活動法人 超音波エレクトロニクス協会 2011年 [査読無し][通常論文]
71. 2P-42 超音波照射を用いたオイルサンドからのビチューメンの低温抽出(ポスターセッション)大川, 浩一, 細川, 亮太, 斉藤, 知直, 中村, 貴司, 川村, 洋平超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 0 31 373 - 374 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2010年12月 [査読有り][通常論文]
72. 2P-35 超音波補助によるシュウ酸を用いた緑色凝灰岩からの鉄抽出効率の改善(ポスターセッション)中村, 貴司, 大川, 浩一, 川村, 洋平, 菅原, 勝康超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 0 31 359 - 360 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2010年12月 [査読有り][通常論文]
73. The sterilization of suspensions contaminated with microorganisms using ultrasound irradiationT.Nakamura, H.Okawa, R.Hosokawa, T.Saito, Y.Kawamura, and, K.Sugawara, 川村, 洋平Jpn. J. of Appl. Phys. 49 07HE11  応用物理学会 2010年08月 [査読有り][通常論文]
74. The Sterilization of Suspensions Contaminated with Microorganisms Using Ultrasound IrradiationTakashi Nakamura, Hirokazu Okawa, Ryouta Hosokawa, Tomonao Saito, Youhei Kawamura, Katsuyasu SugawaraJAPANESE JOURNAL OF APPLIED PHYSICS 49 7 0 - 0 2010年07月 [査読有り][通常論文]
     We investigated the influence of suspended particles on the sterilization efficiency of ultrasound wave applied to microbial suspensions. A microbial solution containing 2:0 × 10 cfu/ml of Bacillus bacteria but no suspended particles was sterilized more efficiently by 28 kHz irradiation inducing a strong impact-like physical action compared to 200 kHz irradiation inducing a strong chemical reaction through the generation of radicals and heat. This sterilization effect was enhanced by the suspension of silicon dioxide or green tuff when irradiated at 28 kHz. However, the irradiation of green tuff microbial suspension at 200 kHz resulted in a remarkable decrease in the sterilization efficiency. This reduction was caused by divalent iron in green tuff reacting with radicals generated by 200 kHz irradiation, thus reducing the amount of radicals used for sterilization. Our results suggest that 28 kHz ultrasound irradiation is optimal for the sterilization of microbial suspensions. © 2010 The Japan Society of Applied Physics. 2
75. Effects of Different Ultrasound Irradiation Frequencies and Water Temperatures on Extraction Rate of Bitumen from Oil SandHirokazu Okawa, Tomonao Saito, Ryota Hosokawa, Takashi Nakamura, Youhei Kawamura, Katsuyasu SugawaraJAPANESE JOURNAL OF APPLIED PHYSICS 49 7 0 - 0 2010年07月 [査読有り][通常論文]
     Low (28 kHz) and high (200 kHz) frequency sonication combined with hot water treatments at 45 and 75 °C were investigated to assess the effects of different ultrasound frequencies and water temperatures on the extraction of bitumen from oil sand. A mechanical stirrer was also used to compare the efficiency of separation. Bitumen extraction tests were performed under argon, air, and nitrogen atmospheres. Sonication at 200 kHz was shown to extract bitumen effectively from oil sand at 75 °C. The bitumen extraction rate for sonication at 200 kHz was slightly higher than that at 28 kHz. For low temperature (45 °C) solutions, only sonication at 28 kHz could extract bitumen from oil sand, demonstrating that sonication at 28 kHz can effectively breakdown the oil sand aggregates into a suspension. © 2010 The Japan Society of Applied Physics.
76. The Sterilization of Suspensions Contaminated with Microorganisms Using Ultrasound IrradiationNakamura, Takashi, Okawa, Hirokazu, Hosokawa, Ryouta, Saito, Tomonao, Kawamura, Youhei, Sugawara, KatsuyasuJpn J Appl Phys 49 7 07HE11 - 07HE11-4 Published by the Japan Society of Applied Physics through the Institute of Pure and Applied Physics 2010年07月 [査読有り][通常論文]
     We investigated the influence of suspended particles on the sterilization efficiency of ultrasound wave applied to microbial suspensions. A microbial solution containing $2.0\times 10^{2}$ cfu/ml of Bacillus bacteria but no suspended particles was sterilized more efficiently by 28 kHz irradiation inducing a strong impact-like physical action compared to 200 kHz irradiation inducing a strong chemical reaction through the generation of radicals and heat. This sterilization effect was enhanced by the suspension of silicon dioxide or green tuff when irradiated at 28 kHz. However, the irradiation of green tuff microbial suspension at 200 kHz resulted in a remarkable decrease in the sterilization efficiency. This reduction was caused by divalent iron in green tuff reacting with radicals generated by 200 kHz irradiation, thus reducing the amount of radicals used for sterilization. Our results suggest that 28 kHz ultrasound irradiation is optimal for the sterilization of microbial suspensions.
77. Effects of different ultrasound irradiation frequencies and water temperatures on extraction rate of bitumen from oil sandHirokazu Okawa, Tomonao Saito, Ryota Hosokawa, Takashi Nakamura, Youhei Kawamura, Katsuyasu SugawaraJapanese Journal of Applied Physics 49 7 07HE12  2010年07月 [査読有り][通常論文]
     Low (28 kHz) and high (200 kHz) frequency sonication combined with hot water treatments at 45 and 75 °C were investigated to assess the effects of different ultrasound frequencies and water temperatures on the extraction of bitumen from oil sand. A mechanical stirrer was also used to compare the efficiency of separation. Bitumen extraction tests were performed under argon, air, and nitrogen atmospheres. Sonication at 200 kHz was shown to extract bitumen effectively from oil sand at 75 °C. The bitumen extraction rate for sonication at 200 kHz was slightly higher than that at 28 kHz. For low temperature (45 °C) solutions, only sonication at 28 kHz could extract bitumen from oil sand, demonstrating that sonication at 28 kHz can effectively breakdown the oil sand aggregates into a suspension. © 2010 The Japan Society of Applied Physics.
78. 20712 磁気車輪を用いた鉄橋非破壊検査装置のための移動機構の開発(一般講演 ロボット)土方, 大輔, 川村, 洋平, 宇都木, 隆裕日本機械学会関東支部総会講演会講演論文集 2010 16 231 - 232 一般社団法人日本機械学会 2010年03月 [査読無し][通常論文]
     We develop a mobile mechanism that can move on the surface of the iron bridge for a non-destructive testing device. This mechanism has four-wheel drive and moves by means of magnetic wheels. It acquires adhesion force efficiently by using the principle of the magnetic circuit. This mechanism achieved vertical plane running. Next, we analyze mechanics when the machine approaches a step. It turns out that getting over steps and climbing a vertical plane become possible by selecting the appropriate parameter. It was confirmed by the experiment.
79. P13 超音波を用いたトリクロロエチレン汚染懸濁液の浄化(ポスター発表)大川 浩一, 中村 貴司, 川村 洋平, 菅原 勝康ソノケミストリー討論会講演論文集 19 45 - 46 日本ソノケミストリー学会 2010年 In this paper, we demonstrate in a treatment method for suspension contaminated with trichloroethylene (TCE). The objectives of the present work are to study the purifying the suspension contaminated with TCE and the precipitating the fine particles in the suspension using ultrasound irradiation. Suspension and solution were prepared by ion-change water, TCE and green tuff. TCE solution (500ppm) was completely decomposed for 2h sonication in argon atmosphere. And TCE in suspension (500ppm) was also confirmed the completely decomposition at same condition. Compared the decomposition rate of TCE in solution and suspension, the value were almost same. Isoelectric zone of green tuff suspension was 1.4-3.8 in pH. Degradation of TCE generated which was able to be acidified the solution and the suspension to the pH level of the isoelectric zone. TCE purifying and solid-liquid separation of the suspension using ultrasound irradiation was feasible.
80. 1Pa-12 超磁歪振動子を用いたHDD工法におけるドリルビット三次元位置推定(ポスターセッション)川村 洋平, 田村 潤平, 持地 英実, 水谷 孝一, 大川 浩一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 31 31 39 - 40 特定非営利活動法人 超音波エレクトロニクス協会 2010年 [査読有り][通常論文]
81. Performance evaluation of Contra-Rotating drill for DIGBOTRyouhei Abe, Youhei Kawamura, Kazushi Kamijima, Kazutosi MurakamiProceedings of the SICE Annual Conference 885 - 888 2010年 [査読有り][通常論文]
     In this research, we suggest and develop a small digging robot. This robot is named DigBot. Conceivable application of DigBot is geotechnical investigation and moon exploration. Basic concept of DigBot is proposed and prototype is manufactured using new drilling method'Contra-Rotating drill'. © 2010 SICE.
82. Development of the landslide observation system using ZigBeeYuya Nakahata, Youhei KawamuraProceedings of the SICE Annual Conference 1191 - 1194 2010年 [査読有り][通常論文]
     Landslides are concern in many parts of Japan, and these measures are currently not sufficient.It is necessary to observe the outbreak of the landslide, and the development of the automatic observation system of the landslide is demanded. Therefore, in this research, we suggest and develop an automatic observation system of the landslide using ZigBee. Then, it was confirmed that whether created system using ZigBee can use for observation landslides. © 2010 SICE.
83. Viscosity Measurement Method using Induced EMF at Coil in PVT ApparatusH.ANDO, Y.KAWAMURA, H.OKAWA, Y.SUGAI, and, K.SASAKI, 川村, 洋平International Symposium on Earth Science and Technology 2009 443-446  2009年12月 [査読有り][通常論文]
84. A Fundamental Study of the Surface-Wave Method: The Use of a Giant-Magnetostriction Vibrator as Seismic SourceA.KAMOHARA, Y.KAWAMURA, Y.NAKAHATA, H.OKAWA, and, K.MIZUTANI, 川村, 洋平International Symposium on Earth Science and Technology 2009 437-442  2009年12月 [査読有り][通常論文]
85. 2P4-17 超音波照射を用いた微生物汚染土壌の浄化処理(ポスターセッション)中村, 貴司, 大川, 浩一, 川村, 洋平, 菅原, 勝康超音波エレクトロニクスの基礎と応用に関するシンポジウム講演予稿集 0 30 317 - 318 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2009年11月 [査読有り][通常論文]
86. 1P4-33 超音波照射を用いたオイルサンドからのビチューメン抽出に関する研究(ポスターセッション)大川, 浩一, 細川, 亮太, 斉藤, 知直, 中村, 貴司, 川村, 洋平超音波エレクトロニクスの基礎と応用に関するシンポジウム講演予稿集 0 30 151 - 152 超音波エレクトロニクスの基礎と応用に関するシンポジウム運営委員会 2009年11月 [査読有り][通常論文]
87. 超音波を利用した比内緑色凝灰岩懸濁液の沈殿処理に関する研究中村, 貴司, 大川, 浩一, 川村, 洋平, 高畑, 重幸, 中, 秀男, 菅原, 勝康環境資源工学 : 資源処理技術 / 環境資源工学会 [編] 56 1 13 - 20 環境資源工学会 2009年04月 [査読有り][通常論文]
     Hinai green tuff is quarried in Odate-shi, Akita prefecture in Japan and used for architectural materials. Hinai green tuff suspension is generated from the cutting and the grinding process and it is necessary to treat the solution with precipitants. A chemical flocculant has been used as a precipitation agent for fine particles in the suspension. However, using a chemical flocculant agent produces a wasteful mixture of particles and flocculants, which are impossible to be used as a resource. Therefore, it is necessary to develop a new precipitation method without using precipitants for green tuff particles. In this study, the zeta potential of Hinai green tuff particles in suspension was measured to gain the basic electrochemical properties of the colloidal suspension. We then developed a new precipitation method using sonochemical reaction at 200 kHz, 200 W. From results of the zeta potential measurement using an electrophoresis method, the particles exhibited −50 mV at pH 7.0 and 0 mV at below pH 4.0. Sonochemical reaction was applied to control the pH of the suspension to precipitate the Hinai green tuff particulate. When ultrasonic irradiation was applied to the Hinai green
88. P21 超音波を用いた有機塩素化合物汚染懸濁液の浄化中村 貴司, 大川 浩一, 川村 洋平, 菅原 勝康ソノケミストリー討論会講演論文集 18 69 - 70 日本ソノケミストリー学会 2009年 We present a method to treat suspension contaminated with trichloroethylene (TCE). We aimed to remove TCE and precipitate the fine particles in the suspension using ultrasound irradiation. The solution was prepared from ion-change water and TCE. The suspension was prepared from the solution and green tuff. TCE solution (500ppm) was completely decomposed by 2h sonication in argon atmosphere. And the complete decomposition of TCE in suspension (500ppm) was also confirmed at the same condition. The decomposition rate of TCE in solution and suspension were almost same. Isoelectric zone of green tuff suspension was 1.4-3.8 in pH. The degradation of TCE acidified the solution and brought the pH level of the suspension to the isoelectric zone. Thus, it is feasible to remove TCE and precipitate fine particles in the suspension using ultrasound irradiation.
89. 1P2-34 超磁歪振動子を震源に用いた表面波探査の有効性の検証(ポスターセッション)蒲原 章裕, 川村 洋平, 中畑 裕也, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 30 30 83 - 84 特定非営利活動法人 超音波エレクトロニクス協会 2009年 [査読有り][通常論文]
90. 地中配管検知を目的とした楕円軌道輝度値法による極浅層映像化川村 洋平, 河 宜成, 蒲原 章裕, 大川 浩一Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan 124 12 801 - 807 資源・素材学会 2008年12月25日 [査読有り][通常論文]
     When underground piping for a water or gas supply is buried, the construction site should be checked in advance, referring to the plan or sign. However, some obstacles, such as unknown pipes or stones, can be encountered. To avoid these cases, an examination of the underground condition is required. The purpose of this study is to detect underground objects that exist in the ultra-shallow layer, where 2-3 m below the surface, and to obtain underground image which is easy to see intuitively. For detection, seismic method is applied. However, this method has two downsides. One is a generally used seismic source not having reproducibility. The other is mixing Rayleigh wave which is one of the surface waves and reflected waves. To compensate these downsides, giant-magnetostriction vibrator was used as a seismic source, and magnified cross-correlation analysis was proposed. Underground image was obtained using combinations of them. In this paper, as the method of underground imaging, new algorithm of elliptic orbit brightness value it was developed by the authors was used.
91. Accuracy Improvement of Cepstrum Analysis Using Giant-magnetostriction Vibrator Applied to Non-destructive Testing for Crack of Rock SlopeM.Asaka, Y.Kawamura, H.Okawa, K.Mizutani, 川村, 洋平Proceedings of the 17th Int. Symposium on Mine Planning and Equipment Selection 744-754  2008年10月 [査読有り][通常論文]
92. 超磁歪振動子を用いたコンクリート構造物・岩盤斜面に対する非破壊検査におけるケプストラム解析の適用性川村 洋平, 浅香 充慶, 河 宜成, 大川 浩一, 水谷 孝一Journal of MMIJ : journal of the Mining and Materials Processing Institute of Japan 124 6 452 - 458 一般社団法人 資源・素材学会 2008年07月25日 [査読有り][通常論文]
     Buildings are often damaged by earthquake and land sinkage. Moreover, in Japan, concrete constructions built during the period of high economic growth are getting old. On the other hand, due to weather and geographical features, the collapse of rock slope occurs in many places. So, authors have been conducting a study of the safety assessment of concrete constructions and rock slope using reflection wave method. In this study, the giant-magnetostriction vibrator was used as a transducer to input the ultrasonic wave into a concrete block. Giant-magnetostriction vibrators have much greater input power than piezo-electric ceramics. So, the safety assessment of large scale objects that do not respond with piezo-electric ceramics is possible. These researches are generally called "Non-destructive testing" and herculean task due to the influence of direct wave, because the output wave contains a wave with direct wave and reflection wave together. In this study, as the method to detect the reflection wave, cepstrum analysis was adopted, and arrival times of reflection waves from the bottom of concrete block are shown. The result of cepstrum analysis is greatly influenced by the noise. To improve the result of analysis, the window function which is used in the process of cepustrum analysis was focused, and reduced the influence of direct wave using input voltage waveform. Moreover, the addition of the results of cepstrum analyses in different frequency was applied and the result was greatly improved. The result of this research shows that the cepstrum analysis with giant-magnetostriction vibrator for non-destructive testing is available.
93. Underground Imaging Method Using Magnified Cross-Correlation AnalysisEuiseong Ha, Youhei Kawamura, Koichi Mizutani, Akihiro Kamohara, Hirokazu OkawaJAPANESE JOURNAL OF APPLIED PHYSICS 47 5 3946 - 3951 2008年05月23日 [査読有り][通常論文]
     When underground piping for a water supply or gas supply is buried, some obstacles such as unknown pipes or stones can be encountered. To avoid such situations, an examination of the underground condition from the ground surface is needed. For such an examination, the ultrashallow reflection method is used. We use a giant-magnetostriction vibrator as a seismic source and a magnified cross-correlation analysis as an analysis method. This analysis is performed to obtain the arrival time of waves reflected from underground objects. In this study, an underground imaging method is proposed using the magnified cross-correlation analysis and a simulation is conducted. Then the experiment of detecting a buried concrete block is conducted. Finally, the imaging method is applied to the experimental result, and then the underground image is obtained. With this imaging method, the position of the buried concrete block can be estimated. © 2008 The Japan Society of Applied Physics.
94. Synthesis of FePO4 cathode material for lithium ion batteries by a sonochemical methodHirokazu Okawa, Junpei Yabuki, Youhei Kawamura, Ichiro Arise, Mineo SatoMATERIALS RESEARCH BULLETIN 43 5 1203 - 1208 2008年05月06日 [査読有り][通常論文]
     Hydrated amorphous FePO was synthesized by a sonochemical reaction method, in which a solution of (NH ) HPO and FeSO ·7H O was irradiated by an ultrasonic wave. From this material, two kinds of cathode materials were easily prepared: (1) an amorphous sample prepared by heating at 350 °C and (2) a crystalline sample prepared by heating at 700 °C. Both samples consisted of homogeneous sub-micron particles. The amorphous sample of FePO exhibited high discharge capacities with more than 100 mAh g in the range of 3.9-2.0 V versus Li/Li at a current rate of 0.2 C. The sonochemical synthesis proposed herein has the following advantages: no use of oxidation agents for production of trivalent iron ions, reduction in reaction time, control of particle size, and enlargement in surface area for the preparation of the cathode material. © 2007 Elsevier Ltd. All rights reserved. 4 4 2 4 4 2 4 -1 +
95. Underground Imaging Method Using Magnified Cross-Correlation AnalysisHa, Euiseong, Kawamura, Youhei, Mizutani, Koichi, Kamohara, Akihiro, Okawa, HirokazuJAPANESE JOURNAL OF APPLIED PHYSICS 47 5:Part 2 3946 - 3951 JAPAN SOCIETY APPLIED PHYSICS 2008年05月 [査読有り][通常論文]
96. A13 超音波を利用した比内緑色凝灰岩懸濁液の沈殿処理に関する研究(口頭発表)中村 貴司, 大川 浩一, 川村 洋平, 菅原 勝康ソノケミストリー討論会講演論文集 17 36 - 37 日本ソノケミストリー学会 2008年 Hinai green tuff is quarried in Odate-shi, Akita prefecture in Japan and used for architectural materials. Hinai green tuff suspension is generated from the grinding process and it is necessary to treat the solution with precipitants. A chemical flocculant has been used as a precipitation agent for fine particles in the suspension. However, using a chemical flocculant agent produces a wasteful mixture of particles and flocculants, which are impossible to be used as a resource. Therefore, it is necessary to develop a new precipitation method without using precipitants for green tuff particles. In this study, the zeta potential of Hinai green tuff particles in suspension was measured to gain the basic electrochemical properties of the suspension. We then developed a new precipitation method using sonochemical reaction at 200kHz, 200W. From results of the zeta potential measurement using an electrophoresis method, the particles exhibited 0mV at below pH 4.5. Sonochemical reaction was applied to control the pH of the suspension to precipitate the Hinai green tuff particulate. When ultrasonic irradiation was applied to the Hinai green tuff suspension, the pH decreased to 4.5 in 70 min and finally reached 3.4 in 180 min. We successfully extracted pure Hinai green tuff particles as precipitates from the suspension using ultrasound irradiation.
97. P07 リチウムイオン二次電池用正極材料LiFePO_4の超音波合成(第I部,ポスター発表)工藤 陽太, 大川 浩一, 川村 洋平, 菅原 勝康, 佐藤 峰夫ソノケミストリー討論会講演論文集 17 54 - 55 日本ソノケミストリー学会 2008年 Lithium iron phosphate has attracted attention as a promising cathode material for lithium ion battery, because of its less expensive, abundance. However, the battery capability of this material is at present limited by its low electronic conductivity and low lithium diffusion rate. In order to improve the poor diffusion of lithium ions and the low electronic conductivity, mainly two possible approaches have been studied. One is to increase the surface area of active materials which can reduce the ion-diffusion pathway, and the other is to deposit conductive carbon layers on the surface to improve electronic conductivity. Since the surface area is dependent on the particle size of LiFePO_4, the synthetic method is very important to control the particle size. In this study, Olivine-type LiFePO_4 was prepared via a sonochemical reaction to gain the fine particles. LiOH・H_2O, (NH_4)_2HPO_4 and FeSO_4・7H_2O were used as the starting materials. An Alcohol was added to the solution of the raw materials. When ultrasonic irradiation upon an alcohol, it is so effective for prohibition of conversion from Fe^<2+> to Fe^<3+> in the solution without reducing agent. The precipitate prepared from the solution gave fine particles of LiFePO_4 after calcination. The LiFePO_4 powders obtained was of homogeneity and globular structure with sub-micron particle sizes.
98. 筑波大学 川村研究室 : Geo-Sensing川村 洋平計測と制御 = Journal of the Society of Instrument and Control Engineers 46 10 815 - 816 2007年10月10日 [査読有り][通常論文]
99. Study on Correspondence between Output Voltage of Cable Sensor for Vibration Detection and VelocityY.Kudo, Y.Kawamura, K.Oumura, H.Okawa, and, K.Mizutani, 川村, 洋平Proceedings of the 16th Int. Symposium on Mine Planning and Equipment Selection 524-531  2007年09月 [査読有り][通常論文]
100. Detection of underground concrete block using giant-magnetostriction vibrator applying magnified cross-correlation analysisEui Seong Ha, Youhei Kawamura, Koichi Mizutani, Hirokazu Okawa, Michinori AsakaJAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 46 7B 4500 - 4503 2007年07月26日 [査読有り][通常論文]
      When underground piping for a water supply or gas supply is buried, some obstacles such as unknown pipes or stones can be encountered. To avoid such situations, an examination of the underground condition from the ground surface is needed. For such an examination, the ultra-shallow reflection method is used. We use a giant-magnetostriction vibrator as the seismic source. In this study, first, the P-wave directivity of the giant-magnetostriction vibrator is clarified. Second, the experiment of detecting a buried concrete block is conducted. In this experiment, the cross-correlation analysis is applied. However, the arrival time of the wave reflected from the concrete block is not confirmed. On the basis of the P-wave directivity of the giantmagnetostriction vibrator, the causes are assumed. To obtain good results, the magnified cross-correlation analysis is proposed. By this analysis, the depth at which the concrete block is buried can be estimated with high accuracy. © 2007 The Japan Society of Applied Physics.
101. Detection of underground concrete block using giant-magnetostriction vibrator applying magnified cross-correlation analysisEui Seong Ha, Youhei Kawamura, Koichi Mizutani, Hirokazu Okawa, Michinori AsakaJapanese Journal of Applied Physics, Part 1: Regular Papers and Short Notes and Review Papers 46 7 B 4500 - 4503 2007年07月26日 [査読有り][通常論文]
      When underground piping for a water supply or gas supply is buried, some obstacles such as unknown pipes or stones can be encountered. To avoid such situations, an examination of the underground condition from the ground surface is needed. For such an examination, the ultra-shallow reflection method is used. We use a giant-magnetostriction vibrator as the seismic source. In this study, first, the P-wave directivity of the giant-magnetostriction vibrator is clarified. Second, the experiment of detecting a buried concrete block is conducted. In this experiment, the cross-correlation analysis is applied. However, the arrival time of the wave reflected from the concrete block is not confirmed. On the basis of the P-wave directivity of the giantmagnetostriction vibrator, the causes are assumed. To obtain good results, the magnified cross-correlation analysis is proposed. By this analysis, the depth at which the concrete block is buried can be estimated with high accuracy. © 2007 The Japan Society of Applied Physics.
102. The detection of a misfiring cylinder of diesel engines in excavation machinery using ALM analysisY. Kawamura, M. Nagayama, M. UjihiraInternational Journal of Mining, Reclamation and Environment 21 2 97 - 110 2007年06月 [査読有り][通常論文]
      Mechanical problems, common in large mining equipment, result in serious losses in operations efficiency and financial return. In this study, a minimum number of sensors was applied on the side of two cylinders of a diesel engine in order to build an abnormality diagnostic system that detects anomalous engine behaviour at an early stage. The study investigates whether or not the misfiring of an engine cylinder can be detected through analysis of acceleration results using an aggregative learning method (ALM). The results show that, using ALM, distinctive differences could be observed in almost every cylinder except those farthest from the accelerometer.
103. 土石流の巨礫の挙動に関する個別要素法シミュレーション川村 洋平, 杉山 文乃, 倉岡 千郎春季大会講演集. I, 資源編 19 1 35 - 36 2007年03月29日 [査読無し][通常論文]
104. ジャイロ・加速度センサを用いた落石軌跡計測に関する基礎研究川村 洋平, 山近 哲志, 細川 雄悟春季大会講演集. I, 資源編 19 1 33 - 34 2007年03月29日 [査読無し][通常論文]
105. 超磁歪振動子を用いたコンクリート構造物損傷検査におけるケプストラム解析の適用性川村 洋平, 浅香 充慶, 河 宜成, 伊藤 優, 水谷 孝一春季大会講演集. I, 資源編 19 1 17 - 18 2007年03月29日 [査読無し][通常論文]
106. 超磁歪振動子とデコンボリューションフィルタを用いた地中埋設コンクリートブロック検知川村 洋平, 河 宜成, 大川 浩一, 浅香 充慶, 水谷 孝一春季大会講演集. I, 資源編 19 1 15 - 16 2007年03月29日 [査読無し][通常論文]
107. 振動検出用ケーブルセンサの出力と物理量との対応関係工藤 優樹, 川村 洋平, 大村 健, 水谷 孝一, 名和 豊春春季大会講演集. I, 資源編 19 1 13 - 14 2007年03月29日 [査読無し][通常論文]
108. 超音波による新手法を用いた鉱山ヘルメットライト用電池の開発中里, 槙吾, 川村, 洋平, 大川, 浩一春季大会講演集. I, 資源編 19 1 11 - 12 2007年03月 [査読無し][通常論文]
109. A1 超音波反応場を利用したリチウムイオン電池用鉄系正極材料の設計大川 浩一, 中村 貴司, 中里 慎吾, 川村 洋平, 佐藤 峰夫ソノケミストリー討論会講演論文集 16 1 - 2 日本ソノケミストリー学会 2007年 The Olivine-type LiFePO_4 was prepared by sonochemical method starting from LiOH・H_2O, (NH_4)_2HPO_4 and FeSO_4・7H_2O. Ultrasonic irradiation upon the solution of raw materials was able to synthesize fine particles of LiFePO_4 and prohibit the conversion of Fe^<2+> to Fe^<3+> in the solution without using a reducing agent. The prepared LiFePO_4 was characterized by XRD and SEM. The shape of the sample was a globular structure and the particle size of that was homogeneous and under sub-micron. The temperature of the solution is an important factor to synthesis LiFePO_4 by the sonochemical reaction. Discharge behavior of LiFePO_4 synthesized sonochemical reaction at 60℃ of the solution temperature exhibited 113mAhg^<-1> in the range of 4.0-3.0V vs. Li/Li^+ at a current rate of 0.2C. The ultrasonic effects on the precipitation of the LiFePO_4 precursor in the solution are very complicated, but one of them may helps nucleation of the LiFePO_4 precursor as a consequence of the collision among solute raw materials.
110. 3-03P-16 S波反射法における表面波の最大減衰点を利用した極浅層地震探査(ポスターセッション 3)蒲原 章裕, 川村 洋平, 河 宜成, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 28 28 389 - 390 特定非営利活動法人 超音波エレクトロニクス協会 2007年 [査読無し][通常論文]
111. 3-03P-15 相互相関重合法を用いた地中映像化手法の提案(ポスターセッション 3)河 宜成, 川村 洋平, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 28 28 387 - 388 特定非営利活動法人 超音波エレクトロニクス協会 2007年 [査読無し][通常論文]
112. 3-02P-12 超磁歪振動子を用いた岩盤斜面における亀裂分布推定のための基礎研究(ポスターセッション 3)中里 慎吾, 川村 洋平, 浅香 充慶, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 28 28 381 - 382 特定非営利活動法人 超音波エレクトロニクス協会 2007年 [査読無し][通常論文]
113. 2-02P-10 超磁歪振動子を用いた非破壊検査におけるケプストラム解析の適用性(ポスターセッション 2)浅香 充慶, 川村 洋平, 中里 慎吾, 大川 浩一, 水谷 孝一超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 28 28 213 - 214 特定非営利活動法人 超音波エレクトロニクス協会 2007年 [査読無し][通常論文]
114. 超磁歪振動子のP波指向性に基づいた極浅層反射法による埋設物検知手法の提案河 宜成, 川村 洋平, 水谷 孝一, 大川 浩一, 浅香 充慶物理探査学会学術講演会講演論文集 = Proceeding of the SEGJ Conference 115 0 261 - 264 2006年10月30日 [査読無し][通常論文]
115. 落石に作用する衝撃加速度と反発係数の関係山近 哲志, 川村 洋平, 氏平 増之, 青島 伸治春季大会講演集. I, 資源編 18 1 131 - 132 2006年03月27日 [査読無し][通常論文]
116. ローテータ方式砕石杭工法を用いた地盤締固め効果の表面波探査による検証伊藤 健, 川村 洋平, 鈴木 康雄, 山本 欣右春季大会講演集. I, 資源編 18 1 125 - 126 2006年03月27日 [査読無し][通常論文]
117. 複素ケプストラムを用いた転石の根入れ深さおよび損傷探査伊藤 優, 川村 洋平, 鶴島 守, 水谷 孝一, 倉岡 千郎, 青島 伸治, 氏平 増之春季大会講演集. I, 資源編 18 1 123 - 124 2006年03月27日 [査読無し][通常論文]
118. 多気筒ディーゼルエンジン失火気筒判定における回転数の推定永山 誠, 川村 洋平, 久保 和良, 氏平 増之春季大会講演集. I, 資源編 18 1 45 - 46 2006年03月27日 [査読無し][通常論文]
119. A6 ソノケミストリーを用いたリチウムイオン二次電池用鉄系正極材料の合成大川 浩一, 中里 槙吾, 矢吹 順平, 川村 洋平, 有瀬 一郎, 上松 和義, 佐藤 峰夫ソノケミストリー討論会講演論文集 15 13 - 14 日本ソノケミストリー学会 2006年 At present, lithium cobalt oxides and lithium nickel oxides are mainly used as cathodes of lithium ion batteries. This is because these materials show very high battery performance. However, they are not suitable for large-scaled batteries such as hybrid vehicles, because they are expensive and poor in resources. We then focused on iron because it is cheaper and more abundant. Iron Phosphate (FeO_4) is one of the most interesting materials in Iron based materials so far because it shows a high discharge voltage of 3.5 volts. The theoretical capacity is 170mAh/g, which is sufficient enough compared to present materials being used as lithium ion batteries. The remarkable feature of FePO_4 is that it can be synthesized in air. Its treatment is very easy but the cycle performance shows poor. In this study, we have tried to obtain good cycle performance and improve discharge capacity of FePO_4 utilizing the sonochemical method. The sonochemical reaction was conducted under the irradiation of ultrasound power 200W and frequency 200kHz for 3hours. The crystalline phase was identified by powder X-ray diffraction. The cathode for the electrochemical characterization was made by mixing powders of the sample, acetylene black and PTFE in 70:25:5 weight ratio under Argon atmosphere. The cathode properties were measured in a galvanic cell with a nonaqueous electrolyte, a polypropylene separator and a Li metal anode. Charge/Discharge performances were evaluated at a current rate of 2C in the voltage range between 2 to 3.9 volts. The first discharge profile obtained for the sample heated at 700℃ is improved about 10% compared with a previous report's one. We could also obtain LiFePO_4 by the sonochemical method.
120. P18 リチウムイオン二次電池用鉄系正極材料Fe_3PO_7の超音波照射合成(ポスターセッション)中里 槙吾, 大川 浩一, 川村 洋平, 上松 和義, 佐藤 峰夫ソノケミストリー討論会講演論文集 15 81 - 82 日本ソノケミストリー学会 2006年 Iron is expected as a positive electrode material because of its large Clarke number. In this reason, we have been interesting in iron based materials and been studying. In this time we focused on Fe_3PO_7. The theoretical capacity as cathode is 777mAh/g. Its large capacity is very attractive to compare to present materials being used as lithium ion batteries (LiCoO_2: 274mAh/g, LiMn_2O_4: 148mAh/g). The literature shows that Fe_3PO_7 was prepared by the two-step solid-state reaction. At first stoichiometric amounts of Fe_2O_3 and (NH_4)_2HPO_4 powders are mixed and heated 950 degrees Celsius for 12hour to synthesize FePO_4. Fe_2O_3 and FePO_4 are mixed and preheated 950 degrees Celsius for 12hour and finally heated at 1050 degrees Celsius and finally Fe_3PO_7 is prepared. Fe_3PO_7 requires a lot of time and high sintered temperature. To improve these problems, we have been studying about an easily synthesis method of Fe_3PO_7. In this study, we used the sonochemical method and try to obtain Fe_3PO_7 by one step reaction.
121. Verification of an effect of soil densification applying gravel drain system using surface-wave method and DEM simulationYouhei Kawamura, Ken Ito, Kinsuke Yamamoto, Tatsuo Sakakibara13th International Congress on Sound and Vibration 2006, ICSV 2006 6 4915 - 4922 2006年 In this research, the validity of soil densification applying gravel drain system was inspected, by practicing a small-scale experiment and a distinct element method simulation. Soil densification applying gravel drain system that was developed by MARUJUN Corporation is one of the effective ways of preventing liquefaction. Because of the peculiarity of the motor, it is possible to hold down the cost, scale and the term of construction compared to conventional methods. Effect of compaction can be expected too, from applying pressure when injecting aggregate from the top. The effect of compaction was verified using surface-wave method. Surface-wave method has been applied to both engineering and earth science problems to image the S-wave velocity of the earth. Surface-wave method can estimate S-wave velocity models that are extremely valuable in geotechnical work. Therefore, surface-wave method has been increasingly used in various civil engineering and environmental investigations. To decide a diameter of auger, distinct clement method (DEM) Simulation was performed. DEM is suitable for the simulation of deformation behavior of a discontinuous model. It assumes that an analysis object is a set of small elements. By solving the equations of motion for each element, behavior of the analysis object is observed. Copyright© (2006) by the International Institute of Acoustics & Vibration.
122. Consideration about effectiveness on magnified cross-correlation analysis in frequency domain by detection of underground pipingEui Seong Ha, Youhei Kawamura, Koichi Mizutani13th International Congress on Sound and Vibration 2006, ICSV 2006 6 4722 - 4729 2006年 The purpose of this research is to detect underground piping, which are buried under 60 cm to 124 cm from surface using seismic method. Seismic method is generally used to inquire underground condition by receiving the reflection waves. Generally as a seismic source a hammer or gunpowder is used. However they are not capable of generating an arbitrary seismic wave. In this research, as a seismic source giant-magnetostriction vibrator was used. This vibrator can generate an arbitrary elastic wave in various frequency domains. As a conventional method, cross-correlation analysis is applied to distinguish reflection waves and other waves. However it is not sufficient to obtain desirable result. Therefore as a new analysis Magnified Cross-Correlation Analysis in Frequency Domain was proposed. To consider effectiveness of this analysis, the experiments of detecting underground concrete blocks and piping were conducted using that analysis. Concrete blocks and piping are buried underground the depth of 60cm to 124cm from the surface. As a result, the depth of underground piping and concrete blocks were estimated in high precision, and the effectiveness of Magnified Cross-Correlation Analysis in Frequency Domain was confirmed. Copyright© (2006) by the International Institute of Acoustics & Vibration.
123. Cepstrum analysis applied to ultrasonic reflection wave detection wave method to investigate the depth and the damage of the pileYu Ito, Youhei Kawamura, Koichi Muzutani, Senro Kuraoka2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 1561 - + 2006年 [査読有り][通常論文]
      In civil engineering, especially in construction sites, it is essential to investigate the degree of damage and the depth of foundation piles and pillars, Ultrasonic wave and elastic impact wave methods are currently used as typical non-destructive test ing methods to be applied to a concrete object such as a foundation pile for construction. The latter is performed with using a hammer as its input making this method inaccurate and hard to obtain the same result each time. Therefore, ultrasonic measurement method was chosen over elastic impact wave method to be applied in this study. However, by using the conventional ultrasonic measurement method, since the input is very small, the depth of the investigation is very shallow. Therefore, if it becomes possible to input ultrasonic wave vibration into the concrete foundation pile, deeper depth investigation with higher precision will be attained. In this study, ultrasonic reflection wave detection method was used in order to measure the length of the pile and to detect the degree of damage in the pile. © 2006 ICASE.
124. Study on estimation of the finite-length unknown input waveform from a given input waveform responseYuki Kudo, Nobuharu Aoshima, Youhei Kawamura2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 213 - + 2006年 [査読有り][通常論文]
      The information obtained by measuring a system can be regarded as a response given by the Black Box when there is an input. In this study, estimation of the finite-length unknown input waveform from a given input waveform response in a second order damped oscillation system is conducted. The theory is shown and verified with the simulation on MATLAB. While the effectiveness of this theory in the real system is shown by carrying out an experiment. The unknown input waveform form is estimated as followed. The impulse response is estimated from the response waveform of the system. Then, Fourier transformation for the response waveform and the estimation waveform of the impulse response was conducted, and the spectrum of the response wave was decided by the spectrum of the estimated impulse response. Lastly, inverse Fourier trans form was conducted to this result. This end result obtained is the estimated waveform of the unknown input waveform. In this experiment, the output waveform of the system was measured with an laser displacement sensor. The result was influenced by the noise, however the input waveform was able to be estimated. © 2006 ICASE.
125. Estimation of the engine revolution for statistical analysis of RMS value by using Prony method to detect misfiring cylinder of the diesel engineMakoto Nagayama, Youhei Kawamura2006 SICE-ICASE INTERNATIONAL JOINT CONFERENCE, VOLS 1-13 4016 - + 2006年 [査読有り][通常論文]
      Mechanical problems with large-scale mining machinery can cause serious losses in operational efficiency and profits. A diesel engine with a misfiring cylinder is likely to break down in a short period of time when the engine is used without maintenance. The authors have developed a new system to detect whether an engine is misfiring and, if so, which cylinder is misfiring. This system will be able to manage the engine from a remote location. In this study, a minimum number of sensors will be applied on two cylinders of the engine in order to detect misfiring cylinder. The measured waveform was analyzed by the statistical analysis of R.M.S value. Dividing up combustion time of each cylinder is the first step for statistical analysis of R.M.S value. In case of idling state of the engine, it is easy to divide up combustion time. But, it is necessary to find engine revolutions under the state of rotational fluctuation of the engine. The period of combustion time vary every hour under the state of rotational fluctuation. Therefore, engine revolutions were computed by using Prony method. The period of combustion time was divided, and R.M.S value was calculated. © 2006 ICASE.
126. P2-19 Validation of Effectiveness on Magnified Cross-Correlation Analysis in Frequency Domain based on Directivity of Giant-Magnetostriction Vibrator(Poster session 2)Ha Eui Seong, Kawamura Youhei, Mizutani Koichi, Okawa Koichi, Asaka Michinori超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 27 27 245 - 246 特定非営利活動法人 超音波エレクトロニクス協会 2006年 [査読無し][通常論文]
127. P2-18 Detection of Concrete Crack Using Giant-Magnetostriction Vibrator(Poster session 2)Kawamura Youhei, Asaka Michinori, Ha Eui Seong, Ito Yu, Okawa Koichi, Mizutani Koichi超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 27 27 243 - 244 特定非営利活動法人 超音波エレクトロニクス協会 2006年 [査読無し][通常論文]
128. Study on the detection of misfiring cylinder in a heavy machinery multi-cylinder diesel engine under the state of rotational fluctuationMakoto Nagayama, Youhei Kawamura, Masuyuki UjihiraSAE Technical Papers 2006年 [査読有り][通常論文]
      Mechanical problems of heavy machinery can cause serious losses . And a diesel engine with a misfiring cylinder is likely to break down in a short period of time. In this system, a minimum number of sensors will be installed in the diesel engine to build a diagnosis system which detects anomaly behavior by analyzing the acceleration waveform using statistical analysis of R.M.S. value. This method is superior to traditional methods in point of simplicity, and this system can be applied to the ready-made machinery easily. This system will make it possible to manage the engine from a remote location by data transfer . However, previous system was limited in case of an idling state of the engine. It was successful to detect misfiring condition of cylinder on the engine under the state of rotational fluctuation in this research. Copyright © 2006 SAE International. [1, 2] [3]
129. 落下シミュレーションにおけるパラメータ同定を目的とした衝撃加速度の検討西山 えるむ, 川村 洋平, 山近 哲志応用力学論文集 9 531 - 538 土木学会 2006年 [査読有り][通常論文]
130. Study on Output Mechanism of Cable Sensor for Vibration DetectionF.Ito, D.Akhmetov, M.Komazaki, H.Tachikawa, M.Ujihira, K.Ohara;Y, Kawamura, 川村, 洋平SICE 41 9 SICE 2005年09月 [査読有り][通常論文]
131. Ultrasonic measurement system for detecting penetration of boulders by autocorrelation analysisY Kawamura, M Tsurushima, K Mizutani, M Ujihira, N Aoshima, S KuraokaJAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 44 6B 4364 - 4369 2005年06月 [査読有り][通常論文]
      An elastic impact wave method is used as a typical nondestructive test method to investigate the depth of boulder penetration. However, in the elastic impact wave method using, for example, a hammer, the discrimination of the reflection wave produced by minute cracks is difficult. Theoretically, if it becomes possible to input the vibration of an ultrasonic domain into artificial structures, such as a concrete and a boulder, with a strong amplitude, deeper investigation depth compared to the conventional way with a high precision will be attained. In this study, a concrete block, with a known size, which was, unlike boulders, not buried under ground, was used as a test piece in a basic experiment. As analysis methods, a wavelet analysis for checking the reflection wave and an autocorrelation analysis for identifying the time tag of the reflection wave were used. As a result, the reflection wave was detected in a down chirp signal from 50 kHz to 40 kHz.
132. Ultrasonic measurement system for detecting penetration of boulders by autocorrelation analysisY Kawamura, M Tsurushima, K Mizutani, M Ujihira, N Aoshima, S KuraokaJAPANESE JOURNAL OF APPLIED PHYSICS PART 1-REGULAR PAPERS BRIEF COMMUNICATIONS & REVIEW PAPERS 44 6B 4364 - 4369 2005年06月 [査読有り][通常論文]
      An elastic impact wave method is used as a typical nondestructive test method to investigate the depth of boulder penetration. However, in the elastic impact wave method using, for example, a hammer, the discrimination of the reflection wave produced by minute cracks is difficult. Theoretically, if it becomes possible to input the vibration of an ultrasonic domain into artificial structures, such as a concrete and a boulder, with a strong amplitude, deeper investigation depth compared to the conventional way with a high precision will be attained. In this study, a concrete block, with a known size, which was, unlike boulders, not buried under ground, was used as a test piece in a basic experiment. As analysis methods, a wavelet analysis for checking the reflection wave and an autocorrelation analysis for identifying the time tag of the reflection wave were used. As a result, the reflection wave was detected in a down chirp signal from 50 kHz to 40 kHz.
133. 重機用ディーゼルエンジンの失火気筒判定システムにおけるALM解析の改善川村 洋平, 永山 誠, 氏平 増之, 伊藤 史人, ダウレン アクメトフ, 青島 伸治春季大会講演集. I, 資源編 17 1 101 - 102 2005年03月28日 [査読無し][通常論文]
134. 音響的手法によるトンネル内温度計測の検討水谷 孝一, 柏崎 賢一, 糸賀 一也, 澤村 喬平, 工藤 功介, 川村 洋平春季大会講演集. I, 資源編 17 1 91 - 92 2005年03月28日 [査読無し][通常論文]
135. 超音波を用いた転石根入れ深さの探査における反射波検出手法川村 洋平, 鶴島 守, 水谷 孝一, 伊藤 優, 氏平 増之, 青島 伸治春季大会講演集. I, 資源編 17 1 89 - 90 2005年03月28日 [査読無し][通常論文]
136. 落石に働く衝撃加速度からみた力学モデルの検討川村 洋平, 山近 哲志, 氏平 増之, 伊藤 健, 青島 伸治春季大会講演集. I, 資源編 17 1 63 - 64 2005年03月28日 [査読無し][通常論文]
137. 斜面切削時の崩壊シミュレーション川村 洋平, 伊藤 健, 山近 哲志, 氏平 増之, 青島 伸治, 榊原 辰雄春季大会講演集. I, 資源編 17 1 61 - 62 2005年03月28日 [査読無し][通常論文]
138. Method of detecting reflection wave using corresponding wave difference analysis for ultrasonic measurement system to detect penetration of bouldersMamoru Tsurushima, Youhei Kawamura, Yu Ito, Koichi Mizutani, Senro Kuraoka, Masuyuki Ujihira, Nobuharu Aoshima12th International Congress on Sound and Vibration 2005, ICSV 2005 5 4286 - 4293 2005年 Presently, because of an economic efficiency or usability, nondestructive test is being used to evaluate the damage level and the size of the concrete structure. Ultrasonic and elastic impact wave methods are the current testing methods of nondestructive test. Authors have developed a new testing method which uses chirp signal of ultrasonic and auto-correlation analysis in order to measure the penetration of the boulder stone into the ground. In our past research, we have successfully presumed the length of 900mm long concrete block and the length of 1460mm long white granite almost identically when the AE transducer received the direct wave and the reflection wave separately. However, when the direct wave and the reflection wave were mixed, we were unable to presume the length from the obtained waveform. In this paper, under the obtained data were mixed the direct wave and the reflection wave, the way to read the arrival time of the reflection wave from the data is referred. Authors group invented the way to use difference of the output waveform from two receivers with which the distance from a transmitter differs. And the result of the experiment with the length of 900mm long concrete block is shown.
139. Study on ultrasonic measurement system to detect penetration of bouldersY. Kawamura, N. Aoshima, M. Tsurushima, Y. Ito, K. Mizutani, M. UjihiraProceedings of the SICE Annual Conference 427 - 432 2005年 Ultrasonic and elastic impact wave methods are used as the typical prototype of measuring concrete objects without breaking them up. However, by using the ultrasonic method, the input is restricted to be very small. Therefore, only the shallow region of the object can be investigated. Also, it is a tedious job to analyze the reflection wave obtained from the elastic impact wave method because of the minute cracks existing throughout the object. It is also known that this test method might damage the object.• Theoretically, if it becomes possible to input vibration of an ultrasonic domain into a concrete object with a high output directly, the depth of the object will be obtained with high precision. In this research, it is aimed to improve the already built ultrasonic investigation system, which uses the output vibration of the piezo-electric ceramics that is constructed by the arbitrary waveform of the high voltage. Here, the target is the length of a concrete test piece. Auto correlation analysis will be used to obtain the arrival time of the reflection wave (also known as the reflection wave), when the direct wave and the reflection wave are clearly separated and the reflection wave recognizable. However, unwanted mixed reflection waves will be present throughout the result of this procedure with the targeted reflection wave to measure. Therefore, the cepstrum analysis method is used. The cepstrum analysis method makes it possible to disregard the unwanted mixed reflection wave in the system and to only get the arrival time of the reflection wave that has reached the targeted length of the test piece. It is a simple method that is applied to the power spectrum of the targeted wave, by taking the logarithm of it and transforming it to time dimension using the inverse Fourier transform. The end result shows the arrival time of the reflection wave. The targeted length of the test piece can be obtained using the arrival time. © 2005 SICE.
140. P3-49 Lamb波を用いたコンビナートにおける超音波鋼管検査に関する基礎研究(ポスターセッション3(概要講演))川村 洋平, 野呂 浩介, 河 宜成, 水谷 孝一, 青島 伸治超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 26 26 437 - 438 特定非営利活動法人 超音波エレクトロニクス協会 2005年 [査読無し][通常論文]
141. P3-46 超音波転石根入れ深さ探査における複素ケプストラム解析の精度向上(ポスターセッション3(概要講演))鶴島 守, 川村 洋平, 伊藤 優, 水谷 孝一, 氏平 増之, 倉岡 千郎, 青島 伸治超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 26 26 431 - 432 特定非営利活動法人 超音波エレクトロニクス協会 2005年 [査読無し][通常論文]
142. P3-45 超磁歪振動子を用いた地中配管検知に関する研究(ポスターセッション3(概要講演))川村 洋平, 河 宜成, 野呂 浩介, 水谷 孝一, 青島 伸治超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 26 26 429 - 430 特定非営利活動法人 超音波エレクトロニクス協会 2005年 [査読無し][通常論文]
143. Study of improving the ultrasonic measurement system to detect penetration of boulders using the cepstrum analysisYouhei Kawamura, Mamoru Tsurushima, Yu Ito, Nobuharu Aoshima, Koichi Mizutani, Senro Kuraoka, Masuyuki Ujihira12th International Congress on Sound and Vibration 2005, ICSV 2005 5 4302 - 4309 2005年 [査読有り][通常論文]
      Ultrasonic and elastic impact wave methods are used as the typical prototype of measuring concrete objects without breaking them up. However, by using the ultrasonic method, the input is restricted to be very small. Therefore, only the shallow region of the object can be investigated. Also, it is a tedious job to analyze the reflection wave obtained from the elastic impact wave method because of the minute cracks existing throughout the object. It is also known that this test method might damage the object. Theoretically, if it becomes possible to input vibration of an ultrasonic domain into a concrete object with a high output directly, the depth of the object will be obtained with high precision. In this research, it is aimed to improve the already built ultrasonic investigation system, which uses the output vibration of the piezo-electric ceramics that is constructed by the arbitrary waveform of the high voltage. Here, the target is the length of a concrete test piece. However, unwanted mixed echoes will be present throughout the result of this procedure with the targeted echo to measure. Therefore the cepstrum analysis method is chose to be used. The cepstrum analysis method makes it possible to disregard the unwanted mixed echoes in the system and to only get the arrival time of the echo that has reached the targeted length of the test piece. It is a simple method that is applied to the power spectrum of the targeted wave, by taking the logarithm of it and transforming it to time dimension using the inverse Fourier transform. The end result shows the arrival time of the echo. The targeted length of the test piece can be obtained using this arrival time.
144. Study on the improvement of the credibility of rockfall simulation -direct measurement of acceleration applied to rockfallsSatoshi Yamachika, Youhei Kawamura, Masuyuki Ujihira, Nobuharu AoshimaProceedings of the 14th International Symposium on Mine Planning and Equipment Selection, MPES 2005 and the 5th International Conference on Computer Applications in the Minerals Industries, CAMI 2005 1403 - 1413 2005年 [査読有り][通常論文]
      For pertinent countermeasure of rockfalls, rockfall simulation was studied many times. Any rockfall simulation has not gotten consistency between the simulation result and real rockfall. There are a few causes. One is whether method of calculation used the simulation approaches the mechanics of real rockfall. Two is whether parameters using the calculation are assigned pertinent value. This study suggests direct measurement of rockfall's detail motion which as method of closuring of the problems. It would be possible to determine pertinent value in parameter by comparing the detail motion to calculation result. In this research, 3-demensional rockfall simulation developing in this laboratory is explained. Then the results of experiments on impact acceleration that applies to rockfalls are shown, and compared to calculational results obtained by collision model using this simulation.
145. DEM simulation of collapse in cutting of slopesYouhei Kawamura, Ken Ito, Tatsuo Sakakibara, Masayuki Ujihira, Nobuharu AoshimaProceedings of the 14th International Symposium on Mine Planning and Equipment Selection, MPES 2005 and the 5th International Conference on Computer Applications in the Minerals Industries, CAMI 2005 606 - 615 2005年 [査読有り][通常論文]
      The slope loses its stability in the process of cutting it, therefore causing the slope to collapse. The slope is cut when activities such as mining, civil work and removal of deposit are done. The slope collapse triggers dangerous accidents. In 1999, an accident of a mining face slope collapse have occurred in Yunicho, Hokkaido and a machinery operator lost his life. The gavel pit where this slope collapse occurred has a mined out area which is reclaimed during the winter season. In the process of reclamation of the mined out area, a lot of snow was mixed with backfill. It seemed that the slope collapse was caused by the water pressure of melted snow and the difference of density between the reclaimed area and the slope. In this research, it is aiming to identify the behavior and mechanism of the slope collapse using distinct element method (DEM). The slope collapse behavior caused by the difference of gravel properties was reproduced using by changing parameters of elements in the reclaimed area.
146. 超音波を用いた杭長探査に関する研究鶴島 守, 川村 洋平, 伊藤 優応用力学論文集 8 951 - 958 土木学会 2005年 [査読有り][通常論文]
147. 落石に働く衝撃加速度計測による落石シミュレーションの改善山近 哲志, 川村 洋平, 氏平 増之応用力学論文集 8 531 - 538 土木学会 2005年 [査読有り][通常論文]
148. 重機用エンジンの失火気筒検出に対するウェーブレット解析の適用川村 洋平, 氏平 増之, 青島 伸治, 伊藤 史人, アクメトフ ダウレン土木学会論文集 = Proceedings of JSCE 0 763 107 - 117 公益社団法人 土木学会 2004年06月20日 [査読有り][通常論文]
      ダンプトラックやパワーショベルといった重機は土木建設現場や資源開発現場において不可欠な存在である. 現在, 簡易で確実かつ迅速に失火気筒を判定できる実用的判定法の開発が望まれている. 本研究ではエンジンブロックの2箇所から計測した加速度波形をウェーブレット解析することにより簡易, 確実, 迅速に失火気筒を判定できるかどうか調べた. 実験の結果, エンジンをベンチに設置した基礎実験により人為的に発生させた12気筒すべての失火状態を時間-周波数マップから読み取ることが可能となっている. 実際に不調が認められている実機の実条件下でのフィールド実験においても, その失火気筒の判定が可能であったことを示す.
149. 写真画像による斜面上の被写体寸法測定法に関する研究 : 斜面の傾斜を考慮した寸法補正法氏平 増之, 中島 一平, 川村 洋平, 川北 稔応用地質 45 1 13 - 21 一般社団法人日本応用地質学会 2004年04月10日 [査読有り][通常論文]
      調査目的の被写体が遠すぎたり危険で近寄れない場合には, 撮影距離とレンズの焦点距離を測定しておき, 写真から簡易的に被写体寸法を算定する方法がある. しかし, 地質調査等で斜面を脚部から撮影するような場合は一枚の写真内に遠い位置の物体と近い位置の物体の両方が写されていることが多く, 画像上で測定した寸法に結像倍率を乗ずるだけでなく斜面の傾斜を考慮した傾斜補正が必要である. 本研究では, 傾斜補正法を明らかにするとともに, 六角形板の寸法, 平板上に450個分布させた岩石の寸法, 発破ずりの寸法に関する補正試験を行った. その結果, 六角形の平板については実寸法の0.85～1.04倍の補正値が得られ, 発破ずりに関しては実測した粒度特性値の0.94倍の補正値が得られたと述べた. 以上, 本論で述べた被写体寸法測定時の傾斜補正法は有効といえる.
150. ALMによる大型建設機械用ディーゼルエンジンの失火気筒判定システムに関する研究川村 洋平, アクメトフ ダウレン, 氏平 増之, 石川 達也, 樋口 澄志春季大会講演集. I, 資源編 16 1 75 - 76 2004年03月29日 [査読無し][通常論文]
151. 移動通信網を用いた重機用多気筒ディーゼルエンジンの失火気筒の予防診断川村 洋平, 氏平 増之, 青島 伸治, 伊藤 史人, アクメトフ ダウレン F.計測自動制御学会論文集 40 2 257 - 266 公益社団法人 計測自動制御学会 2004年02月29日 [査読有り][通常論文]
      A diesel engine with a misfiring cylinder is likely to break down in a short time when the engine is used without maintenance. The authors have developed a method of detecting the occurrence of cylinder misfiring and specifying the misfiring cylinder by using wavelet analysis and statistical analysis on the r.m.s. values of two kinds of acceleration waveforms. This detection method is considered superior to traditional methods, which require several accelerometers, especially in terms of simplicity. Since the devolopment of the method, research has been conducted on semi-automatic processing of measured signals and signal transmission from the worksite to a remote office. Field tests confirmed that 1×10⁵ points of dynamic data could be transmitted through the mobile multimedia network within 15min, and the time for signal processing was within 15min. Final determination on the condition of a diesel engine in heavy machinery could be achieved within 30min. Shortened processing time is expected by improvement of the processing software.
152. Study on the detection of misfiring cylinder in a shipping multi cylinder diesel engine using aggregative learning methodY. Kawamura, M. Ujjhira, M. Nagayama, N. Aoshima, F. Ito, D. AkhmetovProceedings of the SICE Annual Conference 153 - 156 2004年 [査読有り][通常論文]
      In this study, a minimum number of sensors will be applied on the side of two cylinders on the diesel engine in order to build an abnormal diagnosis system which detects anomaly behavior at an early stage by analyzing the acceleration waveform using the ALM method. This measurement system can be applied to the ship afterwards and by using the satellite phone system to transfer the data, it will be possible to manage the state of the engine from an office on land without the usage of a personal computer system on board.
153. Fundamental Study on Ultrasonic Measurement System to Detect Penetration of Boulders Using Auto-correlation AnalysisYouhei Kawamura, Mamoru Tsurushima, Nobuharu Aoshima, Koichi MizutaniIECON 2004: 30TH ANNUAL CONFERENCE OF IEEE INDUSTRIAL ELECTRONICS SOCIETY, VOL 2 2 1795 - 1798 2004年 [査読有り][通常論文]
      Generally, in the estimation of damage and the investigation of the size of every concrete artificial structure thing, nondestructive test is used. An ultrasonic method and an elastic impact wave method are mentioned to the typical thing of a nondestructive test method. The authors have developed a new ultrasonic method by using ultrasonic wave of the chirp signal and auto-correlation analysis. In this paper, the experiment is separated Pattern 1 and Pattern 2. In Pattern 1, ultrasonic transfer characteristics were investigated for concrete blocks. It was confirmed that the frequency components of 40-60kHz had a good permeability with each thickness of concrete blocks. In Pattern 2, experiment of receiving the reflection wave was carried out using concrete block with width of 900mm and ultrasonic wave of the chirp signal. Reflection wave was detected in the down chirp signal from 50kHz to 40kHz. And the length of concrete block was calculated using auto-correlation was set to 898.156mm. Like this, the good result that have little error could get it using this system. © 2004 IEEE.
154. C-2 超音波を用いた転石の根入れ深さに関する基礎実験(測定・映像・非破壊検査)川村 洋平, 鶴島 守, 水谷 孝一, 倉岡 千朗, 青島 伸治超音波エレクトロニクスの基礎と応用に関するシンポジウム講演論文集 25 25 143 - 144 特定非営利活動法人 超音波エレクトロニクス協会 2004年 [査読無し][通常論文]
155. スチールワイヤ型ケーブルセンサと衛星電話を用いた落石予知システムに関する研究 : 防護網がない斜面への適用性に関する試験結果伊藤 史人, 氏平 増之, 安池 雅之, 川村 洋平, 樋口 澄志, 山田 孝, アクメトフ ダウレン, 駒崎 征明応用地質 44 4 223 - 233 一般社団法人日本応用地質学会 2003年10月10日 [査読有り][通常論文]
      最近公表された和歌山県天鳥橋西地区における岩盤モニタリングの結果, 1997年の北海道島牧村第2白糸トンネル巻き出し部の岩盤崩落事故等を参考にすると, 大規模落石や岩盤崩落の前には崩壊岩体境界部から大小の落石が発生し, その頻度が高まると考えられる. 著者らは, 前兆的に発生するこの小礫, 岩塊の落下頻度をモニタリングすることが大規模落石～岩盤崩壊の予知に有効と考えている. 本研究では, スチールワイヤ型ケーブルセンサと衛星電話を組み合わせた落石予検知システムの落石検知能力に関する実験的研究を行った. 衛星電話を経由しての遠隔計測により, 「スチールワイヤ型ケーブルセンサを弾性波伝播媒体となる防護網等がない斜面に敷設した場合においても, 大小の岩塊, 小礫の落下頻度と落下源をモニタリングできること」 を明らかにした. また, 現場側PCに保存している15秒分のデータを分析することにより「落下群の落下速度を求められること」, 「センサ敷設間隔は10mまで広げ得ること」等を明らかにした.
156. On Signal Transmission and Data Processing Rate for Remote Diagnosis of Heavy Excavation MachineryY. Kawamura, M. Ujihira, K. Higuchi, M. Komazaki, D. F. Akhmetov, F. ItoAustralasian Institute of Mining and Metallurgy Publication Series 1 251 - 256 2003年 [査読有り][通常論文]
      A diesel engine with a misfiring cylinder is likely to break down in a short time when the engine is used without maintenance, The authors have developed a method of detecting the occurrence of cylinder misfiring and specifying the misfiring cylinder by using wavelet analysis and statistical analysis on the root mean square (r.m.s.) values of two kinds of acceleration waveforms. This detection method is considered superior to traditional methods, which require several accelerometers, especially in terms of simplicity. Since the development of the method, research has been conducted on semi-automatic processing of measured signals and signal transmission from the worksite to a remote office. Field tests confirmed that 1 × 10 points of dynamic data could be transmitted through the mobile multimedia network within IS minutes, and the time for signal processing was within 15 minutes. Final determination on the condition of a diesel engine in heavy machinery could be achieved within 30 minutes. Shortened processing time is expected by improvement of the processing software. 5
157. Artificial Neural Network Approach for Evaluation of Weight of Fallen ObjectsF. Ito, D. F. Akhmetov, M. Komazaki, M. Yasuike, Y. Kawamura, M. UjihiraAustralasian Institute of Mining and Metallurgy Publication Series 1 47 - 53 2003年 [査読有り][通常論文]
      Remote monitoring of geological situation at distant regions with complicated relief, including reliable detection of the rock falls and estimation of the scale of accidents, is of great importance for practical needs. In the paper, vibration data, caused by fall of sample objects and registered by cable sensors, are processed and analysed in order to construct some measure for the indirect evaluation of weight of fallen objects. Nonlinear models, which based on artificial neural networks (ANN), are proposed for the signal presentation. To improve and simplify the learning and classification abilities of the whole system, the aggregative learning method (ALM) is implemented. ALM features relatively low memory and computational resources needed for the procedure realisation, especially for data classification (recall) stage, in compare to conventional methods. The validity and efficiency of the proposed approach are tested through its application for rock fall detection and weight evaluation system using cable sensors and mobile communication network. Classification abilities of the proposed approach are shown useful for estimation of the fallen object weight. Characterised with high computational efficiency and simple decision-making procedure, the derived method can be useful for simple and reliable real-time monitoring system design.
158. Applicability of the magnification equation of lens for slope surveyM. Ujihira, T. Hzuka, Y. Kawamura, M. KawakitaInternational Journal of Surface Mining, Reclamation and Environment 16 3 230 - 244 2002年09月 [査読有り][通常論文]
      Photography is often used in geological survey, mining engineering or civil engineering to measure the length or width of an object by placing another object such as a scale, a hammer or a cigarette box next to the object. But, it is difficult to place a scale nearby the object when the object is too far and high or too dangerous to get to. In this study, practical applicability of the magnification equation of lens for indirect calculation of the length of a photographed object was examined. From this study, it was found that the applicable distance for the use of the magnification equation of lens was 84 m, even when the focal length was 36mm, and that the applicable distance was more than 300 m with the lens focal length being longer than 100 mm. Moreover, falling behavior, impact load and energy of a rock fall could be calculated readily using obtained information from a photograph.
159. 実機による多気筒ディーゼルエンジンの不燃気筒の判定に関する研究川村 洋平, 氏平 増之, 桐本 賢太, 緒方 純俊, 中村 祥一, 樋口 澄志資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan 118 5 399 - 406 一般社団法人 資源・素材学会 2002年06月25日 [査読有り][通常論文]
      As a motive power in heavy construction machineries including mining and various construction works, a multi-cylinders type of diesel engine is very often used because of its high cost performance. Steady maintaining of diesel engine's operation is substantial in view of economic demands and environmental concerns. To realize this, a practice of early diagnosis and early repair are essential.
     In our previous study using a V-12 type of diesel engine installed on a bench, we demonstrated that a misfiring cylinder could be detected by statistical analysis method using rms value of the acceleration waveforms measured on a single point of the engine block.
     In this paper, the same experimentation and analyses as in the previous study were conducted for two practical machineries that loaded the same type engine of the previous study. Even though the engine was loaded on a practical machinery, it was found that a misfiring cylinder could be detected by the same way as in the previous study. In addition to the analyzing method in the previous study, in this study, we employed a wavelet transform method with the Gabor function as a window, and analyzed the acceleration waveforms. The results of wavelet analysis revealed that a misfiring cylinder could be detected visually from time-frequency charts. With the aid of statistical analysis using rms value, a misfiring cylinder in a multi-cylinder diesel engine can be doubly checked by wavelet analysis.
160. レンズの結像倍率式を用いた遠距離物体の寸法測定法に関する研究氏平 増之, 飯塚 岳彦, 川村 洋平, 川北 稔応用地質 43 1 2 - 13 一般社団法人日本応用地質学会 2002年04月10日 [査読有り][通常論文]
      地質調査等で, 目的の被写体が高すぎる, 遠すぎる, 危険で近寄れない場合には被写体のそばにスケールを置くことができない. しかし, フィルムスキャナや画像処理ソフトウエアが進歩し, ノンプリズム型測距儀が普及してきた今日では, このような場合でも被写体の寸法を画像を用いて測定することが可能と考えられる. 本研究では, レンズの結像倍率式を用いて被写体寸法を間接的に求めようとするときに必要な焦点距離別の撮影限界距離と画像のひずみを, 実測データに基づき検討した. 本論で明らかにした主な内容は以下のようである. (1) ±5%以内の被写体寸法測定誤差を許容すれば, 焦点距離f=100mm以上のレンズを用いることで300m遠方までの被写体寸法を測れる. (2) 画像のひずみは, 焦点距離f=100mm以上のレンズを用いた場合1.0～2.0%以下である. (3) 放射線の入った同心円状のひずみ補正用図形を撮影した後, 画像上の点のあるべき位置からの変位量と光軸からの距離の関係式を用いることで被写体寸法を補正できる. (4) ほかに簡便な方法がない場合にカメラと測距儀を用いて間接的に被写体寸法を測定しようとする本論の方法は有用である. このとき, 距離の正しい測定, 焦点距離が正確なレンズの使用, 被写体像の微小寸法の正確な測定を行うことが重要である.
     本研究では, レンズの結像倍率式を用いて被写体寸法を間接的に求めようとするときに必要な焦点距離別の撮影限界距離と画像のひずみを, 実測データに基づき検討し, 撮影限界距離とひずみ補正法を具体的に示した. 本論で明らかにした内容をまとめると以下のようである.
     1) 地質調査等でカメラを用いて被写体寸法を測定しようとする場合, 被写体寸法はフィルム上の被写体像の微小寸法をフィルムスキャナで測り, これに理論倍率を乗じて求める. このとき, スキャナによる微小寸法測定誤差と画像のひずみが目的とする被写体寸法測定誤差の主な原因になる.
     2) 実測により被写体寸法測定誤差の95%信頼限界を計算し, レンズの焦点距離ごとの撮影限界距離を示した. ±5%以内の測定誤差を許容すれば, 焦点距離f=100mm以上のレンズを用いることで300m遠方までの被写体寸法を測ることができる.
     3) 画像のひずみについて検検討し, f=36, 50mm等, 焦点距離が短いレンズを用いた場合に大きいひずみが現われることを定量的に示した. やはり焦点距離f=100mm以上のレンズを用いることでひずみを1.0～2.0以下の範囲内に抑えれる.
     4) やむを得ずf=36, 50mm等短い焦点距離のレンズを用いる場合には, ひずみを補正することが必要である. 放射線の入った同心円状の図形を撮影した後, 画像上の点のあるべき位置からの変位量と光軸からの距離の関係式を用い, 被写体寸法を補正できる.
     5) フィールドにおいて目的とする被写体の寸法を測定しようとする場合, 他に簡便な方法がないときにはカメラと測距儀を用いて間接的に測定しようとする本方法が有用である. ただし, 距離の正しい測定, 焦点距離が正確なレンズの使用, 被写体像の微小寸法の正確な測定を行うことが重要である.
161. 建設機械用多気筒ジーゼルエンジンにおける不燃気筒の予防診断桐本 賢太, 川村 洋平, 氏平 増之, 緒方 純俊計測自動制御学会論文集 = Transactions of the Society of Instrument and Control Engineers 38 2 230 - 232 計測自動制御学会 2002年02月28日 [査読有り][通常論文]
162. 振動解析による建設機械エンジンの不燃気筒の検出桐本賢太, 川村洋平, 氏平増之, 緒方純俊電気学会計測部会論文集 01 53 29-34  2002年 [査読有り][通常論文]
163. スチールワイヤ型ケーブルセンサの実斜面への適用に関する研究駒崎 征明, 浦田 健司, 伊藤 史人, 氏平 増之, 徳永 哲信, 今野 慎也, 川村 洋平, 樋口 澄志, 川北 稔応用地質 42 5 264 - 273 一般社団法人日本応用地質学会 2001年12月10日 [査読有り][通常論文]
      著者らはケーブルセンサを用いた落石監視システムについて研究を進めてきた. しかし, ケーブルセンサ自体の破断強度は低く, そのまま実環境に敷設するには不十分である. したがって改良型として, ケーブルセンサをスチールワイヤの中心部に巻き込み補強したスチールワイヤ型ケーブルセンサ (SWCS) を提案している. 本研究では, SWCSを実斜面に敷設し実施したフィールド研究の結果, 次の事項が明らかになった. (1) 加速度計をSWCSに取り付け, その外周を手動により打撃する感度試験を行った結果, SWCSの出力電圧と加速度の関係はベキ関数式で示せる. また, この式を用いSWCSの出力電圧波形を加速度波形に変換することができ, センサごとの感度の違いがクリアできることを確認した. (2) 実斜面に格子状に敷設したSWCSは増幅倍率2倍で十分な出力電圧が得られた. また, 各chの出力電圧波形の立ち上がり時刻は落石の下方落下に伴い時間ずれが生じる. この立ち上がり時刻と出力波形により, 落石の落下挙動としての跳躍運動, 衝突, 落下軌跡等を読み取ることが可能である. さらに, トポグラフ表示により, 落石挙動を視覚的に把握できる. (3) SWCSの出力波形の立ち上がり時刻を結ぶ曲線から, 落石特性値 (最大速度残存係数: α, 等価摩擦係数: μ, 脚部における落下速度: V, 並進運動エネルギー: E) を算出でき, 防護工の設計に有効である. また, SWCSを現場に用い長期観測することで, 前兆としての大小の落石の累積頻度を計測することが実用上可能となる.
164. 多気筒ディーゼルエンジンの不燃気筒の判定に関する研究 - 加速度波形のrms値を用いた場合 -川村 洋平, 氏平 増之, 樋口 澄志, 中村 祥一, 駒崎 征明, 伊藤 忠人資源と素材 : 資源・素材学会誌 : journal of the Mining and Materials Processing Institute of Japan 117 6 485 - 493 一般社団法人 資源・素材学会 2001年06月25日 [査読有り][通常論文]
      Big scale construction machinery is absolutely necessary for the mineral resources development and various construction works. Troubles of the machinery give serious losses in the efficiency of operations and also in financial proceeds. In this meaning, machinery maintenance is very important for mining and construction works. Early diagnosis of the machinery is especially important to prevent a serious damage. Recently, diesel engine applied to excavation machinery are highly improved not to discharge exhaust gases of high concentration and to achieve high energy efficiency. However, a diesel engine involving non combustion cylinder has high probability to breakdown in a short time when the engine is used without any maintenance works.
     In this study, autocovariance of acceleration waves of cylinder block was calculated to obtain the period of revolution, and the combustion period of each cylinder was determined. Then rms value corresponding to each combustion period was calculated. Probability of overlapped area of two curves of normal distribution, which were obtained from rms values of normal and non combustion states respectively, was calculated. It was confirmed that non combustion cylinder of a diesel engine of V-12 type could be judged clearly using the relative intensity curve of the probability. This judgement method is considered to be superior to traditional methods where more than several numbers of accelerometers were used, especially from the viewpoint of simplicity.
165. スチールワイヤ型ケーブルセンサの感度に関する実験的研究氏平 増之, 川村 洋平, 樋口 澄志, 佐藤 昌志, 今野 久志, 駒崎 征明, 伊藤 史人応用地質 42 1 15 - 23 一般社団法人日本応用地質学会 2001年04月10日 [査読有り][通常論文]
      振動検出用ケーブルセンサは, 大規模岩盤崩壊に先立つ前兆的小崩落や落石を検知するうえで, また施工時の斜面監視等に有用なセンサであると考えられる. しかし, その破断荷重は0.4～0.5kNであり, そのまま実環境に敷設した場合破断の可能性がある. 著者らは, ケーブルセンサの引張強度を補強するために元のケーブルセンサをスチールワイヤの中心に巻き込んだスチールワイヤ (SW) 型ケーブルセンサを提案している. この場合, ケーブルセンサを取り巻くストランド (鋼線の束) が緩衝材の役割を果たし感度が低下すると予想された. このため, 本研究では, 異なる3つの条件下で元のケーブルセンサとSW型ケーブルセンサの感度の比較試験を行った. その結果, 次の事項が明らかになった. 1) SW型ケーブルセンサをコンクリート床や鋼製覆道等剛な構造物等に点で固定する場合, SW型ケーブルセンサの出力電圧は元のケーブルセンサより低下する. しかし, センサ全体を連続的に接着した場合には出力低下は見られない. 2) ケーブルセンサとスチールワイヤ型ケーブルセンサを地中に埋設した場合, SW型ケーブルセンサの感度は元のケーブルセンサと比較して低下する. しかし, SN比からみると信号とノイズは明瞭に判別でき十分な出力電圧が得られている. 3) SW型ケーブルセンサにおいても出力電圧と加速度の間には本論の図-8, 12, 18中の実験式に示されるようなべき関数関係が存在する. 以上の実験結果からSW型ケーブルセンサは設置状態ごとに加速度換算の実験式を求めておくことで実用に供し得ると判定している.
166. Practical applicability of steel wire cable sensor for rock fall detectionM Ujihira, F Ito, T Tokunaga, Y Kawamura, S Konno, K Higuchi, M KomazakiMINE PLANNING AND EQUIPMENT SELECTION 2001 57 - 62 2001年 [査読有り][通常論文]
      Authors have studied the rock fall prediction system for these several years, in which cable sensor for vibration detection and mobile multimedia network are applied. It was confirmed from field tests that the newly developed steel wire cable sensor, which was installed along an unstable slope in grid pattern, could detect the falling impact even when the weight of a block was 200g and the falling trajectory could be judged from the gap of rise time of wave forms of 9 strings of the sensors stretched in horizontal direction. Topographic figure which was drawn by using the products of amplitudes of wave forms of horizontal and longitudinal steel wire cable sensors could give the falling trajectory visually. We have concluded that the steel wire cable sensor was useful to monitor the instability of the slope.
167. Evaluation of the weight of fallen object using the wave forms measured by cable sensor and mobile multimedia network systemF Ito, S Tsukazawa, M Komazaki, M Ujihira, Y Kawamura, T TokunagaMINE PLANNING AND EQUIPMENT SELECTION 2001 755 - 760 2001年 [査読有り][通常論文]
      Frequency monitoring of small rock fall events is a strong method to predict a slope failure or a rock fall of big scale along the slopes of traffic route and open pit mine. As a monitoring system, authors have proposed a remote monitoring system using cable sensor and mobile multimedia network. Frequency distribution or accumulated curve of rock fall events can be monitored using this system. However, it was very difficult to evaluate the weight of a fallen rock of each event, although the scale of the rock fall could serve us the important information to predict the failure in succession from the rock fall event. For the evaluation of the rock fall scale preceded a slope failure, authors had discussed and judged that wave forms measured by the detection system should be analyzed not only by using amplitude characteristics of output wave forms but also by using the spectrum characteristics in frequency domain. In this paper, it is described that integrated Fourier spectrum and integrated wave forms of acceleration and output voltage of cable sensor are particularly useful to evaluate the weight of fallen object.
168. A study on the detection of non-combustion cylinder of the diesel engine for construction machinery using wavelet analysisY Kawamura, M Ujihira, K Higuchi, K Kirimoto, M Komazaki, F ItoMINE PLANNING AND EQUIPMENT SELECTION 2001 167 - 172 2001年 [査読有り][通常論文]
      A diesel engine involving non-combustion cylinder has high probability to bred in a short time when the engine is used without any maintenance works. In this study, r.m.s. value corresponding to each combustion period of cylinders of diesel engine was calculated. Probability of overlapped area of two curves of normal distribution, which were obtained from r.m.s. values of normal and non-combustion states respectively, was calculated. It was confirmed that non-combustion cylinder of a diesel engine of V-12 type could be judged clearly using the relative intensity curve of the probability. Moreover, wavelet analysis for acceleration wave curves was carried out. It is concluded that almost of all non-combustion states of cylinders could be detected, also performing wavelet analysis for acceleration wave curves of cylinder block.
169. 時間周波数解析による重機エンジンの診断桐本賢太, 川村洋平, 氏平増之, 緒方純俊電気学会計測部会論文集 00 42 13-18  2001年 [査読有り][通常論文]
170. 定規模覆道におけるケーブルセンサと移動通信網を用いた落石検知システムに関する研究駒崎 征明, 平間 和夫, 伊藤 史人, 氏平 増之, 鈴木 新吾, 川村 洋平, 樋口 澄志応用地質 41 4 200 - 209 一般社団法人日本応用地質学会 2000年10月10日 [査読有り][通常論文]
      岩盤斜面での破壊音や落石の衝突振動を広い範囲にわたって監視できる, すなわち測定範囲を点から線, 面へ拡張できる可能性を持つセンサに振動検出用ケーブルセンサがある. この研究では, 実規模覆道内にケーブルセンサを格子状に敷設し, 「落下物の落下位置が二次元的に標定できるか」 , 「落下物の大きさを評価できるか」 , 「加速度計による測定結果との対比ではどうか」 等について実験を行った. 加えて, 新たに開発した移動通信網を用いたデータ伝送システムの動作に関する実験を行った. その結果, 次の事項が明らかになった, または確認された. (1) ケーブルセンサは高い精度を要求していなければ, 加速度計の代替センサとして利用できる. (2) 実規模の覆道においても上部に鋼球を落下させた場合, 落下位置は波形の立ち上がり, 振幅, トポグラフィのいずれによっても標定できる. (3) ケーブルセンサは6gの鋼球の落下振動を検出できる. また, ケーブルセンサからの出力電圧値から落下物重量のオーダの違いを推定できる. (4) ケーブルセンサの長さが増加すると出力の感度が落ちるが, 実験結果から仮に100mのケーブルセンサを用いても実用上十分な感度が得られる. (3) 新たに開発した落石検知システムにおける携帯電話通信網による必要なデータ量 (48Kbyte) の伝送時間は現在のところ3分以内であり, ケーブルセンサを含めた本落石検知システムは実用に供せる可能性が高い.
171. Practical applicability of steel wire cable sensor for rock fall detectionM Komazaki, K Hirama, F Ito, M Ujihira, Y Kawamura, T TokunagaMINE PLANNING AND EQUIPMENT SELECTION 2000 309 - 313 2000年 [査読有り][通常論文]
      Authors propose a monitoring system using cable sensor for rock collapse and fall detection. Practical applicability of this prediction system for concrete structures such as rock-shed or inlets of tunnels had been already confirmed, stretching the sensors in grid pattern to the internal surface of the structures. The tensile strength of cable sensor (CS) is 40 - 50 kg, and not enough for usage under real environmental conditions. For this reason, a steel wire type cable sensor (SWCS) is proposed. Here, a field test of SWCS for practical applicability for rock fall detection was carried out and the following points were made clearly: 1) The output signal level of SWCS is lower than that of CS. However, the sensitivity of SWCS is enough for practical use. 2) The falling trajectory of a rock was visually estimated from topographic method of the output voltage of SWCS. Therefore, SWCS could be recommended for practical use.
172. Practical applicability of steel wire cable sensor for rock fall detectionM Komazaki, K Hirama, F Ito, M Ujihira, Y Kawamura, T TokunagaMINE PLANNING AND EQUIPMENT SELECTION 2000 309 - 313 2000年 [査読有り][通常論文]
      Authors propose a monitoring system using cable sensor for rock collapse and fall detection. Practical applicability of this prediction system for concrete structures such as rock-shed or inlets of tunnels had been already confirmed, stretching the sensors in grid pattern to the internal surface of the structures. The tensile strength of cable sensor (CS) is 40 - 50 kg, and not enough for usage under real environmental conditions. For this reason, a steel wire type cable sensor (SWCS) is proposed. Here, a field test of SWCS for practical applicability for rock fall detection was carried out and the following points were made clearly: 1) The output signal level of SWCS is lower than that of CS. However, the sensitivity of SWCS is enough for practical use. 2) The falling trajectory of a rock was visually estimated from topographic method of the output voltage of SWCS. Therefore, SWCS could be recommended for practical use.
173. 振動検出用スチールワイヤ型ケーブルセンサの感度特性(共著)川村, 洋平土木学会北海道支部論文報告集 56(A) 204-207  2000年 [査読無し][通常論文]
174. スチールワイヤ型ケーブルセンサの斜面への適用に関する研究(共著)川村, 洋平土木学会北海道支部論文報告集 56(A) 208-213  2000年 [査読無し][通常論文]
175. 建設機械のエンジンの異常診断に関する基礎研究川村, 洋平土木学会北海道支部論文報告集 56(A) 296-299  2000年 [査読無し][通常論文]
176. A field test of a rock fall detection system using cable sensor and mobile multimedia networkM. Komazaki, K. Hirama, M. Ujihira, S. Suzuki, H. Saeki, Y. KawamuraInternational Journal of Surface Mining, Reclamation and Environment 13 4 159 - 163 1999年 Cable sensor which is usually used for invader inspection of sensitive places such as atomic power stations and other high security buildings is considered to be available for rock noise and impact detection, because the sensor can detect vibration at any point of a string, and can be used with extending more than a hundred meter or more. From a field test using cable sensor and mobile multimedia network, it was found that the impact source caused by a steel ball dropping in the proximity of the sensing cable could be judged clearly from the order of rise time of signals of cable sensors, amplitudes of wave forms of signals and a topography pictured from peak values of signals transmitted by way of mobile multimedia network. This newly developed system is considered to be applicable not only to detect the resultant impact of fallen rocks but also to monitor the noise produced by the fracture of unstable rocks and sounds of falling rocks along a slope.
177. Applicability of the equation of image magnification of lens for rock engineeringM.Ujihira, T.Iizuka, Y.Kawamura, M.Kawakita, T.Tanabe, 川村, 洋平Proceeding of '99 Japan-Korea Joint Symposium on Rock Engneering 171-176  1999年 [査読有り][通常論文]
178. Study on output characteristics and mechanical strength of the cable sensor for vibration detectionM.Ujihira, Y.Kawamura, M.Sato, H.Konno, M.Komazaki, K.Hirama, 川村, 洋平Proceedings of the 8^th Int. Symposium on Mine Planning and Equipment Selection 539-544  1999年 [査読有り][通常論文]
179. 連続衝撃測定センターの特性試験とその考察(共著)川村, 洋平土木学会北海道支部論文報告集 55(A) 52-57  1999年 [査読無し][通常論文]
180. Rock fall detection system using cable sensor and mobile multimedia networkM Ujihira, S Ogawa, S Suzuki, S Hosoya, H Saeki, M Komazaki, K Hirama, M KawakitaMINE PLANNING AND EQUIPMENT SELECTION 1998 13 4 151 - 156 1998年 [査読有り][通常論文]
      Cable sensor which is usually used for invader inspection to the places such as atomic power stations and other buildings is considered to be available for rock noise and impact detection, because the sensor can detect vibration at any point of a string, and can be used with extending more than a hundred meter or more. From a field test using cable sensor and mobile multimedia network, it was found that the impact source caused by a steel ball dropping could be judged clearly from the order of rise time of signals of cable sensors, amplitudes of wave forms of signals and a topography pictured from peak values of signals transmitted by way of mobile multimedia network. This newly developed system is considered to be applicable not only to detect the resultant impact of fallen rocks but also to monitor the fracturing noises of unstable rocks and falling sounds of rocks along a slope.
181. 落石検知用ケーブルセンサの経時変化と出力波形の特性(共著)川村, 洋平実地技術論文報告集 14 736-742  1998年 [査読無し][通常論文]

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