• 제목/요약/키워드: Transfer Operation

검색결과 1,512건 처리시간 0.029초

동시환승(Timed-Transfer) 버스시스템 (Timed-Transfer of Buses)

  • 고승영
    • 대한교통학회지
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    • 제13권4호
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    • pp.105-115
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    • 1995
  • This paper deals with an operation concept of "time-transfer of buses", in which buses arrive a transfer center at the same time and allow passengers to transfer to other bus lines, so that passengerscan go anywhere all the timed-transfere buses operate with only one transfer. This timed-transfer bus system is known as an efficient operating technique which can be adopted in an area with sparsely distrubuted bus demand. A model of timed-transfer is estabilished in terms of vaious factors such as the expected(or average) arrival time, distribution of arrival time, timed-transfer cycle, shceduled departure time, etc. It is assumed that the objective of timed-transfer bus system is to minimize the total transfer waiting time. The optimal schedualed arrival time or buffer time(time required to arrive ealy in consideration of delay) is analyzed for a general case and various speicial cases. It was found that the optiaml buffer time is an inverse funcion of the timed-transfer cycl and increases with the cycle time, assumin g that there is a fixed scheduled departure time at the transfer cetner regardless of whether one or more buses fail to arrive before the scheduled departure time. If buses are to wait uhtil all the buses arrive at the transfer center, that is, the transfer departure time is vairable, the optimal scheduled arrival times can be obtained by a mathmatical programming.

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열원이 바뀌는 고온용 히트파이프의 천이 과정 동작에 관한 수치적 연구 (A numerical study on the transient operation of high temperature heat pipe with a switching heat source)

  • 박종흥;이재헌
    • 대한기계학회논문집B
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    • 제21권1호
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    • pp.68-78
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    • 1997
  • A numerical study on the transient vapor flow and heat transfer is performed to investigate the ideal switching operation of heat source in a high temperature heat pipe. The cylindrical 2-dimensional compressible laminar vapor flow is assumed for the vapor space and the conjugate heat transfer for the heat pipe wall, wick and vapor space is calculated. The different boundary conditions such as constant heat flux, convective or radiative boundary at the outer wall are used respectively to compare the influence of boundary conditions on the transient operation. The transient temperature profile and the internal flow of the entire pipe for the switching operation are described as a result. The results show that the transient time is not significantly affected by the boundary conditions at the outer wall in present study. During the transition, two independent flows are observed temporarily on the right side and left side of the heat pipe. It is also found that the trend of temperature variation in the vapor region is different from the variation in the wick and wall region.

신호장치에 의한 ATS 신호장치 오동작 방지에 대한 연구 (A Study about Preventing Improper Working of Equipment on ATS System by Signaling Equipment)

  • 고영환;최규형
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2008년도 춘계학술대회 논문집
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    • pp.579-587
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    • 2008
  • Promotion of the line no.2 in Seoul Metro was changing from the existing signaling facilities for ATS(Automatic Train Stop) vehicles to the up-to-date signaling facilities for ATO(Automatic Train Operation). But, in consequence of conducting a trial run after being equipped with the ATO signaling facilities, the matter related to mix-operation with the existing ATS signaling facilities appeared. The operation of the existing ATS signaling system in combination with the ATO signaling system has made improper working related to frequency recognition of the ATS On-board Computerized Equipment. This obstructs operation of a working ATS vehicle. That is, as barring operation of an ATS vehicle that should proceed, it may make the proceeding ATS vehicle stop suddenly and after all, it will cause safety concerns. In this paper, we designed a wayside track occupancy detector that previously prevents improper working related to frequency recognition of the ATS On-board Computerized Equipment by gripping classification and working processes of operating trains throughout transmission of local signaling information from the existing facilities, which does not need to change or replace the existing signaling facilities. Furthermore, we described general characteristics of the wayside track occupancy detector and modeled the IFC(InterFace Contrivance) device and the logical circuit recognizing signal information. Then, we made an application program of PLC(programmable Logic Computer) based on the stated model. We, in relation to data transfer method, used the frame in TCP/IP transfer mode as the standard, and we demonstrated that ATO transmission frequency is intercepted.

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경골에 시행한 유리 생 비골 및 피부편 이식 (Free Vascularized Osteocutaneous Fibular Graft to the Tibia)

  • 이광석;박종웅;하경환;한상석
    • Archives of Reconstructive Microsurgery
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    • 제6권1호
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    • pp.63-72
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    • 1997
  • We have evaluated the clinical results following the 46 cases of free vascularized osteocutaneous fibular flap transfer to the tibial defect combined with skin and soft tissue defect, which were performed from May 1982 to January 1997. Regarding to the operation, flap size, length of the grafted fibula, anastomosed vessels, ischemic time of the flap and total operation time were measured. After the operation, time to union of grafted fibula and the amount of hypertrophy of grafted fibula were periodically measured through the serial X-ray follow-up and also the complications and results of treatment were evaluated. In the 46 consecutive procedures of free vascularized osteocutaneous fibular flap transfer, initial bony union were obtained in the 43 grafted fibulas at average 3.75 months after the operation. There were 2 cases in delayed unions and 1 in nonunion. 44 cutaneous flaps among the 46 cases were survived but 2 cases were necrotized due to deep infection and venous insufficiency. One necrotized flap was treated with latissimus dorsi free flap transfer and the other was treated with soleus muscle rotational flap. Grafted fibulas have been hypertrophied during the follow-up periods. The fracture of grafted fibula(15 cases) was the most common complication and occurred at average 9.7 months after the operation. The fractured fibulas were treated with the cast immobilization or internal fixation with conventional cancellous bone graft. In the cases of tibia and fibula fracture at recipient site, the initial rigid fixation for the fibula fracture at recipient site could prevent the fracture of grafted fibula to the tibia.

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Development of Operation Strategy to improve Efficiency for Twin Automated Transfer Crane in an Automated Container Terminal

  • Park, Byung-Joo;Choi, Hyung-Rim
    • 한국항해항만학회지
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    • 제31권7호
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    • pp.605-611
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    • 2007
  • In order to become a mega hub port, major ports all over the world are making every effort to enhance their productivity through efficiency of internal operation. Accordingly, in order to enhance the competitiveness of a container terminal, an automated container terminal is considered as the best alternative. An automated container terminal is using such automated handling equipment as AGV(Automated Guided Vehicles) and ATC(Automated Transfer Crane). The efficient equipment operation plays a critical role in enhancing the productivity of an automated container terminal. In an automated container terminal, the most important equipments are AGV and ATC. Each block of containers with a vertical layout is generally operating two ATCs. The two ATCs can be crossed or not at each block. In the case of operating crossover ATC, it has an advantage of high flexibility that ATC work is possible at both TP(Transfer Point) of each block. But it has also a disadvantage that the yard has to be operated at a low storage level of containers in the terminal yard. Recently, for automated container terminals, which are being prepared for opening in Korea, they plan to use uncrossed twin ATC in order to make the storage level of their yards high at a low cost. Therefore, studies have to be made in order to increase the efficiency of twin ATC system based on the flexibility that the crossover ATC system has. This research aims to suggest an operation strategy to improve efficiency of twin ATC at each storage block in a yard.

유동 불균일이 전열관 튜브에 미치는 영향 (Influence on heat transfer due to uneven flow)

  • 정재헌;송정일
    • 한국태양에너지학회:학술대회논문집
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    • 한국태양에너지학회 2008년도 추계학술발표대회 논문집
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    • pp.273-279
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    • 2008
  • The purpose of this study is not only to evaluate thermal performance but also to find the stress behavior of heat transfer tubes under the part load operation in Heat Recovery Steam Generator. Flow analysis was performed to know the behavior of exhaust gas from gas turbine and thermal performance was calculated using distribution of hot exhaust velocity. In addition, tubes temperature during operation were gathered from actual plant to verify the uneven flow distribution under part load operation. Stress analysis was performed using tubes temperature data gathered from actual plant under both part and full load operations to know the stress behavior of tubes.

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컨테이너 터미널 계획 평가를 위한 시뮬레이션 연구 (Simulation Study for the Planning Evaluation of Port Container Terminal)

  • 윤원영;안창근;최용석;김갑환
    • 한국항해항만학회:학술대회논문집
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    • 한국항해항만학회 1998년도 추계학술대회논문집:21세기에 대비한 지능형 통합항만관리
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    • pp.117-124
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    • 1998
  • This paper proposes a simulation model which evaluates operation plans of container terminal. The operation plans of container terminal consist of berth plan, load plan, unload plan, yard plan, and equipment plan. It is discussed how to apply the simulation method to evaluate those plans. Simulation analysis is based on data about plans from the operation planning system through an interface program. It is discussed what we should got in the simulation, for example, the statistics about container-handling equipment such as container cranes, transfer cranes, yard tractors, and trailers used in the transportation of containers.

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TCP/IP프로토콜 스택 프로세서 IP의 VLSI설계 (VLSI Design of Processor IP for TCP/IP Protocol Stack)

  • 최병윤;박성일;하창수
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2003년도 하계종합학술대회 논문집 II
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    • pp.927-930
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    • 2003
  • In this paper, a design of processor IP for TCP/IP protocol stack is described. The processor consists of input and output buffer memory with dual bank structure, 32-bit RISC microprocessor core, DMA unit with on-the-fly checksum capability. To handle the various modes of TCP/IP protocol, hardware and software co-design approach is used rather than the conventional state machine based design. To eliminate delay time due to the data transfer and checksum operation, DAM module which can execute the checksum operation on-the-fly along with data transfer operation is adopted. By programming the on-chip code ROM of RISC processor differently. the designed stack processor can support the packet format conversion operations required in the various TCP/IP protocols.

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철도전철화 효과 계량지표 개발에 관한 연구 (A study on development of measuring index about railway electrification effectiveness)

  • 김재희;박용걸;양근율;정호성
    • 한국철도학회:학술대회논문집
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    • 한국철도학회 2006년도 추계학술대회 논문집
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    • pp.1575-1580
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    • 2006
  • High speed and large transfer capability of railroad has been an important issue in Korean since KTX opening at 2004. Improvement projects for railway electrification are progressed in the conventional line as well as high speed line because various operation plan is performed such as interaction between high speed line and conventional line and operation of tilting train etc. Especially, railway electrification has many advantages which are cost effective and eco-friendly. But it also has some problems such as construction costs and accidents due to electrification. Therefore this paper developed measuring index of electrification railway benefit. By comparing between diesel and electrical locomotive, the operations of before and after the electrification and measurements quantitative index such as energy efficiency, enlargement of transfer capability, environmental pollution and maintenance and efficiency of operation is presented. In the future, Overall benefit and cost of railway electrification will be analyzed.

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셀형유연조립시스템에서의 네트웍형 셀배치 (Network-type Cell Layout in Cellular Flexible Assembly Systems)

  • 노인규;최형호
    • 산업경영시스템학회지
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    • 제19권39호
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    • pp.63-73
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    • 1996
  • With the success of flexible manufacturing systems (FMSs), flexible assembly systems (FASs) have been developed to automate factories further. As in a cellular FMS, a cellular FAS is considered as the most flexible and feasible assembly system configuration Because of the differences between manufacturing and assembly operation, the logic of cell formation and cell layout between a FMS and a FAS is not the same. Since the time for assembly operation is usually relatively short, the transfer time is thus very crucial for the performance of assembly systems. Therefore in assembly systems it is important to reduce the transfer time by sequencing operations efficiently and arranging machines like the sequences. The network-type layout is not only feasible for the machine arrangement based on operation sequences, but it has also layout flexibility. Therefore it is a reasonable layout configuration for cellular FASs. This paper presents a method for the cell layout based on the network-type layout in a cellular FAS design.

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