SEISAN KENKYU
Online ISSN : 1881-2058
Print ISSN : 0037-105X
ISSN-L : 0037-105X
Volume 69 , Issue 6
Showing 1-25 articles out of 25 articles from the selected issue
Introduction to Special Section
Research Flash
  • Kengo HAYASHI
    2017 Volume 69 Issue 6 Pages 309-313
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Historical built environments are cultural resources and their discovery is the role of architectural history.However, they have not been investigated sufficiently in megacities, whose urban areas are too extensive to be fully explored with existing methods. This study aims to discover historical built environments in Jakarta, the second largest megacity in the world. With a new method utilizing GIS, it investigates historical highdense neighborhoods called kampung, which means “village” in Indonesian language. It clarifies that 58% of the residential areas in Jakarta are historical kampungs, which has a relatively high proportion of the natives of Jakarta. The method should be further developed for its application to other megacities.

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  • Kentaro OKAMURA
    2017 Volume 69 Issue 6 Pages 315-317
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Disaster reconstruction is a phenomenon strongly regulated by the society in which it occurred. Therefore, comparative analysis of disaster reconstruction from ancient times to the present and in various areas makes it possible to distinguish the characteristics of the society and the era in which the disaster occurred. In particular, the subject is the reconstruction after the Showa Sanriku tsunami. In this paper, the characteristics of "modern reconstruction" in Japan is introduced and a plan is drawn for the construction of disaster reconstruction history in Japan and the world.

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  • Dmitry KUZNETSOV
    2017 Volume 69 Issue 6 Pages 319-322
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    This report summaries the current issues related to the study of the Soviet contributions to the to the world built environment. The questions are related to the definitions, the process of case study selection and the impact analysis. Some aspects of the possible approach to its analysis and representative examples that can be seen in China will illustrate the point.

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Field Report
Introduction to Special Section
Research Flash
  • Itsuki SATO, Reiko KUWANO, Takeshi SATO
    2017 Volume 69 Issue 6 Pages 329-332
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Focusing on the fact that slope disasters such as muddy flow and long distance flow are triggered by volcanic pumice layers with high void, we reproduced extremely loose soil with volcanic cementation by adding cement, and investigated its strength characteristics. The extremely loose structure soil with cementation showed a large negative dilatancy, and had a high Poisson's ratio and a high shear strength until failure of cementation. In the undrained compression test, after the shear strength reached a peak and the cementation was lost, a brittle behavior was observed in which the shear strength converged to a residual value.

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  • Naoto KOMINAMI, Reiko KUWANO
    2017 Volume 69 Issue 6 Pages 333-336
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    A large sinkhole occurred in Miyakonojo, Miyazaki on Sept. 19, 2016 due to a typhoon which hit the area, leading to soil outflow covering the road nearby. Although the interchange was stopped temporarily, no human casualties occurred in this accident. This accident was a fortunate case, but sinkholes may lead to serious casualties depending on time and place. Therefore it is important to investigate the cause and take measures to prevent these accidents beforehand. Surveys including dynamic cone penetration tests and surface wave surveys were conducted to understand the cavities and loosening underground of the accident site.

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  • Mayuko HOTTA, Reiko KUWANO
    2017 Volume 69 Issue 6 Pages 337-340
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS
    Subsurface cavities have to be treated properly because cavities can cause road subsidence and become a sinkhole. In this study, data of subsurface cavities obtained in Fukuoka city were analyzed considering geographic or environmental factors to establish the correlation using GIS. According to the correlation and weighting among factors, a cavity potential value, which shows how each place is likely to have cavity was defined and calculated. The aim of this study is to develop a cavity potential map using the cavity potential values calculated at each grid (250m×250m). In addition, dimensions of target cavities were sorted out to grasp the image of the target cavities.
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  • Junpei KANAI, Ken’ichi KAWAGUCHI
    2017 Volume 69 Issue 6 Pages 341-344
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    When it is difficult to move to a high place from tsunami, many companies have devised “tsunami personal shelter” as a last resort that secures a very small space and evacuates. In this report, we investigated current tsunami personal shelters and human injury criteria of passengers and considered the survival time in the shelter from the view point of human tolerance based on respirable oxygen. The products of tsunami personal shelter can be largely classified into two types according to the scale, and we found that the small types need to be considered regarding the safety evaluation of passengers and the survival time based on respirable oxygen.

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  • Pujin WANG, Ken’ichi KAWAGUCHI
    2017 Volume 69 Issue 6 Pages 345-349
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    In Japan, large span buildings are employed as shelters for residents when earthquake or other disasters occur. Fallings of ceilings or other hanging components in these buildings usually happen in a sudden and are dangerous to human body. Damage detection and safety judgements of ceilings are mainly relied on the observation with human (especially by experts, First Class Authorized Architects in Japan, for example) naked eye. Damage detection and safety evaluation of ceilings or hanging components can be transformed into computer vision problems. The prevailing deep learning method, especially the convolutional neural networks (ConvNets), is a potent algorithm to construct a damage detection system. In this report, an architecture of deep learning model applying ConvNets is realized to evaluate the damage degree of ceilings. In the discussion part, more detailed discussions of the deep learning model are also performed to make a better understanding of it.

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  • Eka JULIAFAD, Kimiro MEGURO, Hideomi GOKON
    2017 Volume 69 Issue 6 Pages 351-355
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Mega-Earthquake has been predicted by many experts, which will threat Padang City, Indonesia in future.In order to reduce the disaster risk due to the seismic activity, it is needed to develop an integrated risk assessment tool that can cover many elements which are involved on the system of disaster risk reduction. This research aims to observe and recognize the environmental system in Padang City, West Sumatra, Indonesia, as a preparation towards the development of assessment tool to reduce impacts due to earthquake disaster. By interviewing the experts from building offices in Padang City about building quality and construction system, Google earth street view, street survey and building document analysis, building typology and building quality in Padang City have been examined. Building law, building code and building local regulation have been reviewed. This research found that the building typology is dominated by RC building low-mid storey with greater than 50% of building population. Review of building law, code and regulation compared to observed construction method, show that the seismic vulnerability is high. The land acquisition problem which covers 43% of land area which is related to unique tribe system also seems to contribute to the low quality of building construction in Padang City.

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  • Natsumi HARA, Hideomi GOKON, Kimiro MEGURO, Than Yu KHIN.
    2017 Volume 69 Issue 6 Pages 357-360
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Yangon, the biggest city in Myanmar, has a population of 5.14 million resident stands in the vicinity of Sagaing fault. Considering the impact of past seismic activities in this region, it is important to develop and execute earthquake disaster risk reduction strategies by proper assessment of the current situation. To evaluate the seismic risk of Yangon city, Aung (2016)[1] developed fragility functions for the existing reinforced concrete buildings. However, the strength values which used in the fragility functions might differ from the actual concrete strengths. Therefore, this study mainly focuses on developing the revised fragility functions based on material testing and the field survey at construction site. In this paper show the results of some interviews about construction situation and pre-investigation of steels obtained from a construction site in Yangon.

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  • Kazuma HASEKURA, Hideomi GOKON, Kimiro MEGURO, Shunichi KOSHIMURA
    2017 Volume 69 Issue 6 Pages 361-365
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Approximately 561㎢ of the Pacific coast from Aomori prefecture to Chiba prefecture is flooded on Mar. 11, 2011 due to the Great East Japan earthquake. Remote sensing is effective to grasp the extensive tsunami flooded areas. In this paper, we report the result of detecting flooded areas in ricefield using X-band SAR data and optical satellite image.

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  • Masahiro SAWATSUBASHI, Takashi KIYOTA
    2017 Volume 69 Issue 6 Pages 367-371
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS
    In order to investigate a mechanism of slaking-induced landslide, case-study-analyses based on soil moisture obtained by satellite data and a series of direct creep shear tests with dry-wet cycle were conducted. The case-study-analysis indicates that there were many landslide cases in slakable rock/soils, which had been less sensitive to the precipitations. The tendency may be explained by using deviation of soil moisture. The direct creep shear test for gravelly mudstone showed a creep failure by dry and wet cycles. However, there was no clear relation between number of dry-wet cycles and a change of water absorption ratio of the mudstone particles.
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Field Report
  • Masataka SHIGA, Takashi KIYOTA, Reiko KUWANO
    2017 Volume 69 Issue 6 Pages 373-378
    Published: November 10, 2005
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Since November 2013, a number of sinkholes have been observed in the Armala area of Pokhara Valley, Central Nepal, affecting the farming lands and the local residents. According to the local people, more than

    200 sinkholes have been occurred. The authors have investigated the affected area six times from 2014 through

    2016. The topographic data was obtained by using UAV and the subsurface soil structures were investigated through surface wave test and cone penetration tests. The results indicates that an erosion of weak soil layers in buried old river channels along the main river, Seti River, may have caused the sinkhole damages.

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Research Flash
Introduction to Special Section
Research Review
  • Shigeru OWADA, Hidetoshi YOKOI
    2017 Volume 69 Issue 6 Pages 387-397
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    As typical appearance failures appearing on the surface of injection molded products, there are flow marks with striped pattern (tiger stripe shape). These flow marks consist of glossy and cloudy bands appearing alternately on the surface of molded products. One major feature is that their phases are reversed on the front and back sides of the molded products. This paper aims to clarify generation mechanism of the flow mark by discussing typical analysis cases and our analysis results of the melt transcription process from the correlation between the surface features and the melt flow behavior by visualization using the flow front tracking system that is developed by the authors. In addition, measures against this failure are discussed based on the generation mechanism.

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  • Junichiro TOKUTOMI, Jun YANAGIMOTO
    2017 Volume 69 Issue 6 Pages 399-403
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    The range of applications of copper electric wire in automobiles is becoming broader owing to the increase in the use of embedded computer-controlled devices. At present, the demand for lightweight vehicles is necessitating the use of ultrafine copper wires. In the present study, new continuous bending-drawing process to manufacture ultrafine electric wire is proposed, and the mechanical properties and microstructure evolution of copper alloy deformed by the process was systematically investigated. It was confirmed that change of deformation induced microstructure that was introduced by the process have great effects on the successful manufacturing of ultrafine wire with excellent mechanical properties.

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Research Flash
  • Koki TAHARA, Toshiki NIINO
    2017 Volume 69 Issue 6 Pages 405-408
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    MID(Molded Interconnect Device) is injection molded product with metal film formed on the surface. It has Electrical and Mechanical function. Aiming at apply MID to mechatronic devices such actuators and sensors, the authors research the development of MID with EHD(Electro Hydro Dynamics) pump function using MID technology. EHD pump is an application of a functional fluid flowing when electric field is applied. It does not require a mechanical driving part and can be used as a small pump. The authors developed the EHD pump that has dual helix electrodes on internal surface of flow path. The pump at a voltage of 1.4kV caused a flow of EHD fluid at a flow rate of 6.5cm3/min.

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  • Peiwen DENG, Osamu SAITO, Yoji OKABE
    2017 Volume 69 Issue 6 Pages 409-413
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Impact damage is the most fatal damage that the carbon fiber reinforced plastic (CFRP) skin-stringer composite structure suffers from. In order to reliably detect impact damages with different size and location using structural health monitoring system, the configuration of the macro-fiber composite (MFC) transmitters and fiber Bragg grating (FBG) sensors should be optimized. In this research, authors attempted to model a homogeneous frustum-of-a-cone region with the reduction of quasi-isotropic stiffness matrix for FEM simulation of Lamb wave propagation. The decreasing rate of the stiffness matrix was determined based on the velocity change of ultrasonic waves and the cross-section observation of the impact-damaged area. Finally, the validness of this simplified modelling method was quantitatively confirmed through the comparison with the multiple delamination modelling.

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  • Kensuke TSUCHIYA, Taiichiro MICHIMOTO, Takumi MIYAKOSHI
    2017 Volume 69 Issue 6 Pages 415-418
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    This paper proposed methods of fabricating microstructures on the surface of a roller mold using composite plating. The results of the research were as follows; (1) We succeeded at high density co-deposition of microparticles on the surface of a cathode by first performing plating with high current density using the sedimentation co-deposition method, and then performing a second step of plating with low current density. (2) The above method was successful in creating microstructures of microparticles on the surface of a cylindrical roller mold. (3) The above roller mold could be used to successfully emboss microstructures onto resin film surface.

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  • Shotaro KADOYA, Fuminobu KIMURA, Yusuke KAJIHARA
    2017 Volume 69 Issue 6 Pages 419-422
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    We experimentally investigated the direct joint sterngth between anodized aluminum alloy and injected polymer. The direct joining process consists of two key technique; metal surface roughening and polymer injection molding. We utilized anodizing method as a roughening process and formed 20 – 300 nm pores on metal surface. The anodized metal pieces were successfully joined with injected polymer and the tensile shear strength showed over 10 MPa. Tensile test result shows the aspect ratio of the anodized pores could affect the joint strength.

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  • Tsuyoshi FURUSHIMA
    2017 Volume 69 Issue 6 Pages 423-427
    Published: November 01, 2017
    Released: November 30, 2017
    JOURNAL FREE ACCESS

    Novel heat-assisted dieless forming apparatus with high frequency induction heating. laser and acetylene burner for tubes is developed. Circular and non-circular metal microtubes is fabricated successfully under tension motion in the dieless forming process. Macro and micro size metal bellows is fabricated and the formed shaped can be controlled by compression motion in the dieless forming. The superplstic dieless forming with ultra-high temperature is applied to zirconia ceramic tube for further miniaturization of the tube. Finally, the validity of developed heat-assisted dieless forming apparatus can be demonstrated experimentally.

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