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Hirofumi TANAKA, Shuhei YAMAMOTO, Takashi OSHIMA, Masashi MIWA
2018Volume 59Issue 3 Pages
169-175
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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This study describes the development of methods to detect and predict localized rapid deterioration of track irregularity based on data measured with high frequency. First of all, a highly accurate position correction technique was developed. This technique seeks out phases where the correlation coefficient between waveforms of the different measured data reaches a maximum, and corrects these phase gaps. The automatic extraction of localized rapidly deteriorating track irregularity is made possible from the difference in measured data which has already had its position errors corrected. Secondly, a method for predicting track irregularity was developed. This technique predicts the track irregularity stochastically through updates using new measurement data, applying the Bayesian theorem. Finally, these techniques were applied to field data, confirming their effectiveness.
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Hikaru TANIGAWA, Shuhei KIKKAWA, Takatada TAKAHASHI, Yoshitsugu MOMOYA
2018Volume 59Issue 3 Pages
176-180
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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We developed a new solid-bed track equipped with resilient sleepers (STR) using the shear-key on each side of the sleepers to resist lateral load, to achieve the efficient construction work. As a result of full-scale track model tests, we confirmed that the STR has sufficient performance. The STR was actually adopted in the construction, and it was confirmed that the construction cost of the concrete trackbed could be cut by 60 %, compared with the existing one, reducing the overall construction cost by 20 %. Furthermore, the narrower concrete trackbed makes track laying 1.7 times faster, reducing the construction time.
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Tadashi DESHIMARU, Shingo TAMAGAWA, Masato NOGUCHI, Hiroo KATAOKA
2018Volume 59Issue 3 Pages
181-187
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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Regarding Japanese test methods for rail fastening systems, it was confirmed that the rail tilting angle obtained in a biaxial loading test did not agree with the angle calculated using a conventional rail tilting analysis model. To address this problem, a calculation method for biaxial loading using an FEM analysis model, where various stiffness properties regarding the rail fastening systems can be expressed as non-linearity, was proposed and its validity was confirmed. In addition, a study on the optimization of a method for testing rail restraint was carried out through experimental validation under various conditions.
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Naoya OZAKI, Takuya WATANABE, Noriko FUKASAWA
2018Volume 59Issue 3 Pages
188-193
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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Climate change has led over recent years to a rise in short, heavy rain and there is concern that tornadoes and floods etc. will also increase. RTRI is therefore developing a dynamic hazard mapping system as a technique to reduce injury to railway passengers and damage to railways in case of such disasters. Using the results from hazard mapping evaluations, an algorithm was developed to aid decision making about where to stop trains, and when necessary, where to evacuate passengers. This paper reports on the algorithm for managing train operations in such circumstances and offers guidance for evacuating passengers.
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Ryosuke MATSUMOTO, Daiki OKUDA, Noriko FUKASAWA
2018Volume 59Issue 3 Pages
194-200
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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In order to plan high-speed rail transport services efficiently, it is necessary to be able to forecast fluctuations in passenger demand based on historical ridership data. Forecasting is difficult however, because of the number of components making up passenger demand. An effective way to forecast demand therefore should be to decompose these fluctuations into several independent demand components, which can then be forecast individually. This study applied an independent component analysis to decompose the fluctuation into several independent components. A method was then developed to forecast the fluctuation in passenger demand based on actual ridership data, calendar array, and number of people mobilized for large events.
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Taketoshi KUNIMATSU, Takahiko TERASAWA, Yoko TAKEUCHI, Daisuke TATSUI
2018Volume 59Issue 3 Pages
201-206
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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In recent years, various intelligent signalling systems such as moving block systems have been proposed and put into operation to increase transport capacity. Given the cost of replacing a signalling system it is important to be able to estimate the effectiveness of these new signalling systems. This research aimed to develop a method for simulating moving block systems. The simulation system can predict train traffic conditions and the passenger flows when the moving block system is in operation, while taking into account operational driving restrictions. The simulator was applied to an actual commuter line, to evaluate the effectiveness of the moving block system.
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Minoru SHIMURA, Tomoyoshi USHIOGI, Masateru IKEHATA
2018Volume 59Issue 3 Pages
207-211
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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Deer-train collisions have become a serious problem in Japan. Deer have been observed entering tracks through gaps in fences or at level crossings. To keep deer away from railway lines, an acoustic deterrent was developed and tested for effectiveness. The deterrent consists of a device that emits deer alarm calls and dog calls. Field observations revealed that playing back the deterrent sound towards deer near a track made them run away immediately. According to a survey on the frequency with which deer were observed near railway lines, emission of the deterrent sound from a train resulted in a 45 % reduction in the frequency with which deer were observed for every 100 km of train operation. These results confirmed the effectiveness of the deterrent sound as a measure to prevent deer-train collisions.
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Yasuhiro KITAMURA, Takafumi INOUE, Ayanori SATO, Ryo NAKAMURA, Noriko ...
2018Volume 59Issue 3 Pages
212-216
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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To prevent decision-making errors through training and education, it is necessary to evaluate personal decision-making traits. Two decision-making tasks were developed which make it possible to identify individual differences in decision-making. A decision confirmation exercise was designed to assess the tendency to omit confirmation tasks, while a modified Iowa Gambling Task (work version IGT) was developed to estimate the degree of preference for short-term gains. The validity of these exercises was then tested using functional magnetic resonance imaging (fMRI).
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Ryo NAKAMURA, Yasuhiro KITAMURA, Takafumi INOUE, Ayanori SATO, Noriko ...
2018Volume 59Issue 3 Pages
217-220
Published: August 01, 2018
Released on J-STAGE: September 01, 2018
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Preventing communication errors is essential for ensuring safety in the work place in railways. This study describes the construction of a "Causal model of communication errors in the railways" from the analyses of accident reports and feedback on experience of communication errors. Through this model, it was found that certain methods, such as "talk-back," "confirmation talk" and "learning ambiguous expressions" were effective in preventing communication errors. A training method to teach these skills was proposed and its effectiveness was confirmed through experiments.
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