• Title/Summary/Keyword: Railways

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Evaluation of the Performance of Transit Assignment Algorithms for Urban Rail Networks (도시철도 교통량 배정 알고리즘의 적합성 평가)

  • Jung, Dongjae;Chang, Justin S.
    • Journal of the Korean Society for Railway
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    • v.17 no.6
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    • pp.433-442
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    • 2014
  • This paper evaluates the performance of transit assignment algorithms for urban rail networks. The accuracy of the algorithms is essential not just for travel forecasting but also for the area of applications such as the assessment of road vulnerability and the fare adjustments between train operating companies. Nonetheless, the suitability and caveats for the series of computational steps have not yet been much discussed. This study thus considers the characteristics that are appropriate for investigating Seoul rail travelers using three representative transit assignment algorithms: the optimal strategy algorithm, route choice algorithms, and the Dial's algorithm. Both the theoretical foundation and the empirical performance are examined. The results demonstrate that the Dial's algorithm is superior in terms of the theoretical soundness and the computational efficiency.

Reconnecting the Trans-Korean Railway and future aspirations of Northeast Asia Railway Network (최근 남북.대륙철도 협력현황과 동북아철도협력 구상)

  • Na, Hee-Seung
    • Proceedings of the KSR Conference
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    • 2006.11b
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    • pp.1029-1036
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    • 2006
  • South and North Koreas are putting forth efforts to overcome the distrust and animosity of the past 50 years to open an era of harmony and cooperation where the two halves can work together for mutual benefits. As part of those efforts, both parties are working now to reconnect the railways between the North and the South that remained broken for the past 60 years. In addition, the restoration of Trans-Korean railway paves the way for the "Silk Road Railway" which links European continent to Asian regions and Pacific Rim. The restoration project acts as a conduit for cooperation within in the Northeast Asian continent, hence, an important tool for facilitating peace and prosperity within the Northeast Asian region. Notably, the Railway project is regarded as the cardinal future-oriented peace building project for cultivating constructive, cooperative relations (Trans-Korean Railway and Trans-Asian Railway works) by stimulating human resources and commodity flows through railroad transportations. Northeast Asian region takes on a similar instance to the unification of European continent through its astounding development in railroad transportation, i.e., the international re-construction of Railroad lines will act as a catalyst to link Eurasian areas into one regional community for cooperation and peace. At present, the government is creating a momentum to bind trans-Eurasian railroad works and an initiative for "Northeast Asia Railroad networks and consultative organization". The South Korean administration paves the way to develop railroad network within South-North Korean, Russia and Eurasian region. It also fosters railroad cooperation with China for people and goods transports. To achieve such objectives, the project requires wide publicity and cross-border cooperation from concerned countries. The blueprint would have to be drafted up for Northeast Asian railroad train demonstration runs, Northeast Asian transportation agreements, with a bid to promote constitute Northeast Asian Railroad Consultation body. Moreover, the government would also have to prepare both, a draft of the linkage and the mandated standardized proposal.

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A Study on Gradual Changes in Railway Organization During Japanese Colonial Period (일제 강점기 철도관련 조직의 변화에 관한 연구)

  • Lee, Yongsang;Chung, Byunghyun
    • Journal of the Korean Society for Railway
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    • v.19 no.2
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    • pp.251-261
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    • 2016
  • In this paper, changes of railway-related organization during the Japanese colonial period were studied indepth. The railway-related organizations were expanded from the Railway Management Bureau in 1906 (Residency-General). In 1910, this bureau changed to the General of Chosun Railway Bureau (Government-General) and the Chosun Railway Bureau (Government-General). In the 1940's, it developed into an organization called the Transport Bureau, dealing with the whole transport service. The number of employees in the railway sector increased along with the expansion of the organization and the establishment of a training institution for better recruitment. After examining the period of the construction of railway and connection system, which is deeply related to the railway organizations of the Japanese colonial period, this paper analyzes the transformation process of railway-related laws and organizations. Furthermore, this paper finds common characteristics and differences between railways in a comparison of three countries: Chosun, Japan and Taiwan.

Acoustic Performance Evaluation and Prediction for Low Height Noise Barriers Installed Adjacent To Rails Using Scale Down Model (축척 모형을 이용한 근접 저상 방음벽의 음향성능평가 및 예측)

  • Yoon, Je Won;Jang, Kang Seok;Cho, Yong Thung
    • Journal of the Korean Society for Railway
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    • v.19 no.2
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    • pp.124-134
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    • 2016
  • Research on low height noise barriers installed adjacent to railways to reduce the height of the noise barrier has actively progressed in many countries except Korea. The performance of low height noise barriers is evaluated to identify barrier acoustic characteristics using a scale model of the barrier in the present research. As shown in the experimental results, if it is considered the installation of 'ㄱ' type noise barrier, sound absorption material should be installed on both the top and the vertical surfaces of the barrier to improve insertion loss. Also, an analytical method such as the boundary element method, rather than a simple empirical equation, is required to evaluate the insertion loss of the barrier. In addition, noise level increase in passenger position is very small if a barrier with sound absorption material is installed. Finally, the two dimensional boundary element method is implemented to predict the acoustic characteristics of the low height barrier; the possibility of the application is confirmed from a comparison of the results of measurements and predictions.

Study on the Introduction of EMC Engineering System in Korea (전자파 엔지니어링 제도 도입 방안에 관한 연구)

  • Chung, Yeon-Choon
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.23 no.8
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    • pp.942-949
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    • 2012
  • In order to ensure the safety of the large-scale public facilities, the analysis of EMC(ElectroMagnetic Compatibility) of electronic systems included in the facilities is very necessary. The reason is that the system-level EMC of the facility could be not guaranteed, even if individual equipments included in the facility are satisfied with their EMC requirements. As a result, the system-level evaluation and analysis of EMC should be carried out in order to establish the reliable operations of safety and mission-critical electronic systems. This paper analyze the relevant legal systems of domestic and other countries, and furthermore case studies of system-level EMC approaches were analyzed in the specific applications of electric railways, building, automobile, petroleum refinery systems. And the introduction of related systems in Korea is proposed, and main parts and problems to be looked at each proposed measures are discussed. The results are expected to be utilized in the introduction of the system-level EMC engineering, and contributed in national security and the protection of people's life, body and their properties.

Effects of Cyclic Thermal Load on the Signal Characteristics of FBG Sensors Packaged with Epoxy Adhesives (주기적인 반복 열하중이 패키징된 FBG 센서 신호 특성에 미치는 영향)

  • Kim, Heonyoung;Kang, Donghoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.41 no.4
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    • pp.313-319
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    • 2017
  • Fiber optics sensors that have been mainly applied to aerospace areas are now finding applicability in other areas, such as transportation, including railways. Among the sensors, the fiber Bragg grating (FBG) sensors have led to a steep increase due to their properties of absolute measurement and multiplexing capability. Generally, the FBG sensors adhere to structures and sensing modules using adhesives such as an epoxy. However, the measurement errors that occurred when the FBG sensors were used in a long-term application, where they were exposed to environmental thermal load, required calibration. For this reason, the thermal curing of adhesives needs to be investigated to enhance the reliability of the FBG sensor system. This can be done at room temperature through cyclic thermal load tests using four types of specimens. From the test results, it is confirmed that residual compressive strain occurs to the FBG sensors due to an initial cyclic thermal load. In conclusion, signals of the FBG sensors need to be stabilized for applying them to a long-term SHM.

Prediction of the remaining service life of existing concrete bridges in infrastructural networks based on carbonation and chloride ingress

  • Zambon, Ivan;Vidovic, Anja;Strauss, Alfred;Matos, Jose;Friedl, Norbert
    • Smart Structures and Systems
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    • v.21 no.3
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    • pp.305-320
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    • 2018
  • The second half of the 20th century was marked with a significant raise in amount of railway bridges in Austria made of reinforced concrete. Today, many of these bridges are slowly approaching the end of their envisaged service life. Current methodology of assessment and evaluation of structural condition is based on visual inspections, which, due to its subjectivity, can lead to delayed interventions, irreparable damages and additional costs. Thus, to support engineers in the process of structural evaluation and prediction of the remaining service life, the Austrian Federal Railways (${\ddot{O}}$ BB) commissioned the formation of a concept for an anticipatory life cycle management of engineering structures. The part concerning concrete bridges consisted of forming a bridge management system (BMS) in a form of a web-based analysis tool, known as the LeCIE_tool. Contrary to most BMSs, where prediction of a condition is based on Markovian models, in the LeCIE_tool, the time-dependent deterioration mechanisms of chloride- and carbonation-induced corrosion are used as the most common deterioration processes in transportation infrastructure. Hence, the main aim of this article is to describe the background of the introduced tool, with a discussion on exposure classes and crucial parameters of chloride ingress and carbonation models. Moreover, the article presents a verification of the generated analysis tool through service life prediction on a dozen of bridges of the Austrian railway network, as well as a case study with a more detailed description and implementation of the concept applied.

A design and implementation of Intelligent object recognition system in urban railway (도시철도내 지능형 객체인식 시스템 구성 및 설계)

  • Park, Ho-Sik
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.11 no.2
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    • pp.209-214
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    • 2018
  • The subway, which is an urban railway, is the core of public transportation. Urban railways are always exposed to serious problems such as theft, crime and terrorism, as many passengers use them. Especially, due to the nature of urban railway environment, the scope of surveillance is widely dispersed and the range of surveillance target is rapidly increasing. Therefore, it is difficult to perform comprehensive management by passive surveillance like existing CCTV. In this paper, we propose the implementation, design method and object recognition algorithm for intelligent object recognition system in urban railway. The object recognition system that we propose is to analyze the camera images in the history and to recognize the situations where there are objects in the landing area and the waiting area that are not moving for more than a certain time. The proposed algorithm proved its effectiveness by showing detection rate of 100% for Selected area detection, 82% for detection in neglected object, and 94% for motionless object detection, compared with 84.62% object recognition rate using existing Kalman filter.

Resonance Characteristics of a Arch Bridge for High-Speed Railways (고속철도 아치교량의 공진특성)

  • Nam, Deok Woo;Choi, Hong Kil;Kim, Kyoung Nam;Jung, Kyoung Sup
    • Journal of Korean Society of Steel Construction
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    • v.20 no.4
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    • pp.455-467
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    • 2008
  • The dynamic vehicle running tests were performed to analyze dynamic behavioral characteristics such as displacement, strain history loop and vibration acceleration in arch bridges. Also, the validity of the modeling was verified by comparing the results of the tests and those of the structural analysis modeling. With the resonance revision of verified modeling, when the ratio of excited frequencies to natural frequencies exceeds ${1{\pm}0.04}$, the stability of the bridge is obtained. Also, in the event of resonance by speed parameter, the second mode shape is dominant to the dynamic behaviors of arch bridges. It is found that manipulating the parameters involving arch ribs can increase the second mode natural frequency. It makes critical velocity greater than operational velocities to guarantee the stability of arch bridges.

Risk Analysis of Suspension Bridge by a Linear Adaptive Weighted Response Surface Method (선형 적응적 가중 응답면기법에 의한 현수교의 위험도 분석)

  • Cho, Tae Jun;Kim, Lee Hyeon;Cho, Hyo Nam
    • Journal of Korean Society of Steel Construction
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    • v.20 no.1
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    • pp.93-104
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    • 2008
  • study deals with the reliability assesment for the 5-year phases of a suspension bridge construction in Korea. The main objectives of this study are; (1) the evaluation of the reliability of a suspension bridge by considering an ultimate limit state for the fracture of main cable wires, (2) the determination of the critical phases among 28 construction stages for the deck erection, and (3) the evaluation of the reliability of the limit state for the erection control during construction stages. The research and the design of the suspension bridge have been focused on the state of construction mainly based on empirical data. Based on the recent survey of the distribution of accidents in Korean railways, over 80% of the accidents related to the uncertainties in human error, planning, design, materials and loads during construction have ben reported before the completion of construction. While many researches have evaluated the safety of bridges, the uncertainties in the construction phases have not been well treated in a guidelines or a specifications. An improved adaptive response surface method is used for the risk assessment in the construction phases of the target suspension bridge.