• Title/Summary/Keyword: Transport capacity

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Evaluation of Train Capacity Pattern Considering Customer Demands (고객수요를 고려한 열차용량패턴에 관한 연구)

  • Kim Dong-Hee;Kim Seong-Ho;Hong Sun-Heum
    • Proceedings of the KSR Conference
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    • 2004.06a
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    • pp.507-513
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    • 2004
  • In the railway system, transportation plan corresponds to a m aster plan for transport services. This service plan must be constructed to minimize operational cost or maximize revenue considering transportation demands and resource capacities in the railway operation company, and it includes several sub-planning activities such as train operation frequency plan, train (schedule) plan, train capacity assignment plan, and rolling stock requirement plan. In these sub- planning processes, train can be con side red as a product for providing customer services, and customer demands and operational advantages must be considered. In this paper, we present an effect estimation system for the train capacity pattern in a train schedule, and the effect of capacity pattern can be expressed as minimum spilled demand, minimum train service cost, and maximum train revenue or profit.

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Determination of Two-Lane Highway Capacity and Level of Service in Korean Rural Roads (우리나라 양방향 2차선 도로의 용량 및 서비스 수준 체계에 관한 연구)

  • 최재성
    • Journal of Korean Society of Transportation
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    • v.9 no.1
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    • pp.5-18
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    • 1991
  • Two-Lane, two-way roads account for approximately 92% of total road length in Korea and accomplish the majority of regional transport activities. Nevertheless not too many research have been made on two-lane roads particularly efficiency related topics such as capacity and travel time studies. In this study a full scale data collection was conducted using video equippments on rural two-lane roads to determine capacity Passenger Car Equivalents(PCE) and Level of Service criterion. Various PC programs were utilized to reduce traffic data and Walker ME? and Headway Method were employed to determine PCE's for heavy vehicles. The reseach has shown that capacity and PCE's for two-land two-way roads in Korea are 3200 pcph and 1.1∼1.9 resectively. In addition percent time delay was used as the basis of developing Level of service criterion on two-lane roads in Korea.

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Study on Transport Current Properties of HTS cable connected with SFCL by using YBCO Thin Film type wire (YBCO 박막형 선재를 이용한 초전도 전류제한기의 연계에 따른 고온 초전도 케이블의 사고전류 통전 특성에 관한 연구)

  • Lee, Dong-Hyeok;Kim, Yong-Jin;Han, Byeong-Seong;Du, Ho-Ik;Han, Sang-Cheol;Lee, Jeong-Pil
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.43-43
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    • 2010
  • HTS(High Temperature Superconductor) cable has a high possibility of practical use due to the possibility of low voltage and high capacity transmission caused by its lower power loss than copper cable. On the other hand, when fault current occurred, resistance increase caused by superconductivity loss, the amount of power supplies has diminished, furthermore, it's necessary to take the possible danger of damage to HITS cable into account. Therefore, an effective plan for dealing with the above problem is to link HITS cable to SFCL. In this study, we researched the possibilities of normal transport current as well as the safety of HITS cable by analyzing the properties of transport current in HITS cable connected with SFCL.

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Analysis of Current Distribution of HTSC Power Cable Considering Shield Layer (차폐층을 고려한 고온초전도 전력 케이블의 전류분류 해석)

  • Lee, Jong-Hwa;Lim, Sung-Hun;Ko, Seok-Cheol;Park, Chung-Ryul;Han, Byoung-Sung;Hwang, Si-Dole
    • Proceedings of the KIEE Conference
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    • 2004.04a
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    • pp.12-14
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    • 2004
  • Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of import ant parameters in high-temperature superconduting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and AC loss. In this paper, the transport current distribution at conducting layers was investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer and compared with the case of without shield layer. The transport current distribution due to of the contact resistance and the pitch was improved in the case of HTSC power cable with shield layer from the analysis.

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Error Adaptive Transport Protocol in Variable Error Rate Environment for Wireless Sensor Networks

  • Dang, Quang-Bui;Hwang, Won-Joo
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.32 no.4B
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    • pp.208-216
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    • 2007
  • Wireless Sensor Networks (WSNs) are characterized by low capacity on each nodes and links. Wireless links have high bit error rate (BER) parameter that changes frequently due to the changes on network topology, interference, etc. To guarantee reliability in an error-prone environment, a retransmission mechanism can be used. In this mechanism, the number of retransmissions is used as a parameter that controls reliability requirement level. In this paper, we propose an Error Adaptive Transport Protocol (EATP) for WSNs that updates the number of retransmissions regularly to guarantee reliability during bit error rate changes as well as to utilize energy effectively. The said algorithm uses local information, thus, it does not create overhead problem.

Analysis of the Travel Distance in the Multiple-load Carrying Automated Guided Vehicle Systems (다부하를 운반하는 무인운반차시스템에서 운반거리의 분석)

  • Chang Suk-Hwa
    • Journal of Korean Society of Industrial and Systems Engineering
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    • v.28 no.1
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    • pp.55-63
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    • 2005
  • This paper is to analyze the travel distance and the transport size of the vehicle when the AGV carries multiple-load in the tandem automated guided vehicle systems. The size of multiple-load represents the number of load that the AGV can carry simultaneously. The AGV can carry simultaneously multiple-load that load types are different. The transport system of the manufacturing system is a tandem configuration automated guided vehicle system, which is based on the partitioning of all the stations into several non-overlapping single closed loops. Each loop divided has only one vehicle traveling unidirectionally around it. The AGV of each loop has to have sufficient transport capacity that can carry all loads for given unit time. In this paper, the average loaded travel distance and the size of feasible multiple-load of the vehicle are analyzed. A numerical example is shown.

Analysis of Current Distribution of Multi-Layer HTSC Power Cable dut to Pitch length and winding direction (피치길이와 결선방향에 따른 다층 고온초전도 전력케이블의 전류분류 분석)

  • Lee Jong-Hwa;Lim Sung-Hun;Ko Seokcheol;Park Chung-Ryul;Han Byoung-Sung;Hwang Si Dole
    • Proceedings of the KIEE Conference
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    • summer
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    • pp.1133-1135
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    • 2004
  • Superconducting transmission power cable is one of interesting parts in power application using high temperature superconducting wire. One of important parameters in high-temperature superconducting (HTSC) cable design is transport current distribution because it is related with current transmission capacity and ac loss. In this paper, the transport current and magnetic field distributions at conducting layers were investigated through the analysis of the equivalent circuit for HTSC power cable with shield layer. The transport current distribution due to the pitch length and winding direction was improved in case of HTSC power cable with shield layer.

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Development of an Appraisal Model for Petroleum Storage and Transport Policy for a Petroleum Production Company (XX정유사의 석유제품 저유 및 수송정책평가모형의 개발)

  • 노정현;임채욱
    • Journal of Korean Society of Transportation
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    • v.11 no.3
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    • pp.49-66
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    • 1993
  • The successful management of logistics in an organization requires the careful coordination and manipulation of both movement and storage. In this study, we can show what is the most efficient and the cheapest method to transport the petroleum products under a few constraints with the model of linear programming. And also, the model can give some important informations so as what is the best coverages of each terminals by types, how many products should be exchanged among each companies and which terminals or complexes are economically prior to the others. Even we can understand that the duality is one of the useful measures to evaluate the economical efficiencies of transportation and storage related elements such as complex and terminal location, transport mode, storage tankage capacity and in/outflow facilities of terminals etc.

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Estimation of Road Capacity at Two-Lane Freeway Work Zones Considering the Rate of Heavy Vehicles (중차량 비에 따른 편도 2차로 고속도로 공사구간 도로 용량 추정)

  • Ko, Eunjeong;Kim, Hyungjoo;Park, Shin Hyoung;Jang, Kitae
    • The Journal of The Korea Institute of Intelligent Transport Systems
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    • v.19 no.2
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    • pp.48-61
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    • 2020
  • The objective of this study is to estimate traffic capacity based on the heavy-vehicle ratio in a two-lane freeway work zone where one lane is blocked by construction. For this, closed circuit television (CCTV) video data of the freeway work zone was collected, and the congestion at an upstream point was observed. The traffic volume at a downstream point was analyzed after a bottleneck was created by the blockage due to the upstream congestion. A distribution model was estimated using observed-time headway, and the road capacity was analyzed using a goodness-of-fit test. Through this process, the general capacity and an equation for capacity based on the heavy-vehicle ratio passing through the work zone were presented. Capacity was estimated to be 1,181~1,422 passenger cars per hour per lane (pcphpl) at Yeongdong, and 1,475~1,589pcphpl at Jungbu Naeryuk. As the ratio of heavy vehicles increased, capacity gradually decreased. These findings can contribute to the proper capacity estimation and efficient traffic operation and management for two-lane freeway work zones that block one lane due to a work zone.

Prediction of Chloride Profile considering Binding of Chlorides in Cement Matrix

  • Song, Ha-Won;Lee, Chang-Hong;Ann, Ki Yong
    • Corrosion Science and Technology
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    • v.8 no.2
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    • pp.81-88
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    • 2009
  • Chloride induced corrosion of steel reinforcement inside concrete is a major concern for concrete structures exposed to a marine environment. It is well known that transport of chloride ions in concrete occurs mainly through ionic/molecular diffusion, as a gradient of chloride concentration in the concrete pore solution is set. In the process of chloride transport, a portion of chlorides are bound in cement matrix then to be removed in the pore solution, and thus only the rest of chlorides which are not bound (i.e. free chlorides) leads the ingress of chlorides. However, since the measurement of free/bound chloride content is much susceptible to environmental conditions, chloride profiles expressed in total chlorides are evaluated to use in many studies In this study, the capacity of chloride binding in cement matrix was monitored for 150 days and then quantified using the Langmuir isotherm to determine the portions of free chlorides and bound chlorides at given total chlorides and the redistribution of free chlorides. Then, the diffusion of chloride ion in concrete was modeled by considering the binding capacity for the prediction of chloride profiles with the redistribution. The predicted chloride profiles were compared to those obtained from conventional model. It was found that the prediction of chloride profiles obtained by the model has shown slower diffusion than those by the conventional ones. This reflects that the prediction by total chloride may overestimate the ingress of chlorides by neglecting the redistribution of free chlorides caused by the binding capacity of cement matrix. From the evaluation, it is also shown that the service life prediction using the free chloride redistribution model needs different expression for the chloride threshold level which is expressed by the total chlorides in the conventional diffusion model.