• 한국통신학회논문지
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• 제28권5A호
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• pp.323-332
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• 2003

본 논문에서는 광원이 불필요하며 단일 광섬유를 통하여 양방향 전송이 가능한 base station용 광송수신기 모듈을 제안하였다. 제안한 시스템에서는 써큘레이터와 Mach-Zehnder 변조기로 구성된 ring-type의 base station에서 central office로부터 하향 전송된 광신호의 일부를 재사용하여 상향신호 전송에 사용한다. 시스템의 성능을 평가하기 위해서 IS-95 CDMA 신호 전송을 통한 ACPR 특성과 14개의 캐리어 신호 전송을 통한 CNR을 측정하였다.

• 전자공학회논문지A
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• 제31A권10호
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• pp.21-30
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• 1994

We discussed the Distributed Control System's design on preface and analyzed time of the real-time communication by using designed system. The DCS proposed in this thesis was implemented to network file system having recovery advantage and shared memory method to access file system of a Remote Station with ease. Also, this system minimized the network delay-time by using the real-time VME147 board. In implemented DCS, the performance analysis of real-time process of a Remote Station was done to get the total time for reak-tune communication from a Remote Station to the Central Station after terminating of process. For the analysis of system performance, we experiented by three steps. Firstly, we measuredthe processing the of LOOP function that real-time CPU convertes to-2,500~10.000 values from the input data of the Analog Interface Card. Secondly, we measured the processing time of the LOGIC function and the LOOP function. Lastly, we measured total processing time for communication from a Remote Station to the Centrol Station.

• 대한기계학회:학술대회논문집
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• 대한기계학회 2002년도 학술대회지
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• pp.843-846
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• 2002

Unlike ordinary train, the HST(High Speed Train) is operated at a very high speed, which may cause pressure transient problems when the HST is passing through a station. In the present study, the wind pressure caused by the passing HST was measured in the Cheonan HST station and compared with the numerical simulations. For the measurement, the HST was passing through the station at speeds of 240 km/h north bound and 150 km/h south bound. MEMS based differential pressure transducers are used to measure pressure variation at various locations in the station. It is shown from the results that measured data are in good agreement with CFD simulation with moving mesh technique for the train movement. With the present validation of CFD simulation, the CFD simulation may effectively aid the design of future HST station.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 1999년도 추계종합학술대회 논문집
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• pp.121-124
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• 1999

In a packet-switched wireless cellular network, a packet destined to a mobile station is queued at a base station and then broadcast over the base station's cell. When an active mobile station leaves a cell, there re-main packets which are destined to the mobile and not yet delivered to it at the cell's base station. For application which are sensitive to packet losses, such back- logged packets must be forwarded to the new base station. Otherwise, an end-to-end retransmission may be required. However, an increase in packet delay is incurred by employing the packet forward scheme, since a packet may be forwarded many times before it is delivered to the destined mobile station. For an enhanced quality-of-service level, it is preferred to reduce tile packet delay time. In this paper, we develop an analytical approximation method for deriving mean packet delay times. Using the approximation and simulation methods, we investigate the effect of network parameters on the packet delay time.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1239-1243
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• 2007

Autonomous Station Control System is automatic route control system of large-scale station. The system has flexibility of system step-by-step construction and expandability. A method of step-by-step construction for Autonomous Station Control System has system expansion and subsystem software expansion. The system has autonomous controllability and autonomous coordinability for system step by step construction. With property for a basis, each of subsystem communicates data field. Also, Each subsystem has its own management system, Autonomous Data Manager to manage itself and coordinate with the others. This paper make clear test method for Autonomous Station Control System expansion and software expansion. The first test method of system increasing construction is single station construction test. The second of method is connecting test the neighbor's Autonomous Station Control System. The third of method is connecting test the Autonomous Line Management System. Also, the test method of software expansion take the case of route control subsystem.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 춘계학술대회 논문집
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• pp.1466-1474
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• 2007

In large station with high density traffic, trains is hardly controlled by CTC but by station dispatcher because CTC has difficulties in monitoring all states of affairs happening within the station such as departs and arrivals of many trains from different lines and shunting trains between yards and platforms, etc. Therefore station dispatcher has to make quick decision about how to schedule all trains including trains to arrive and depart before long. And such decisions become harder when an unexpected delay occurs. This study suggests a mathematical model and algorithm about how to detect in advance and resolve efficiently the conflicts occurring within a station and it will be shown how to reduce delay using our approach by means of analysing the schedule of ChyungRyangRi station.

• 한국생물환경조절학회:학술대회논문집
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• 한국생물환경조절학회 2004년도 추계학술대회 논문집
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• pp.76-79
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• 2004

• 한국농공학회논문집
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• 제47권6호
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• pp.15-24
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• 2005

The normalization on the characteristics of water level change at the upstream gauging station was attempted according to the operation of drainage sluice gate of the Geumgang estuary dam. The characteristics were normalized by the analysis of water level change and by the linear-regression of the water level data measured at the inner station of Geumgang estuary dam and upstream gauging station. The results of normalization may be referred to the management of Geumgang estuary lake, the operation of pumping and drainage stations in the shore of the lake. The mean response time of water level change on Ibpo, Ganggyeong and Gyuam water level station were 39,81 and 160 minutes, when sluice gate was opened respectively. The mean velocity of surface wave, the mean displacement of water level change, the mean time of water level change and the mean rate of water level change varied largely depending on the location of gauging station and the characteristics of stream section of the water level gauging station.

• 국제초고층학회논문집
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• 제5권2호
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• pp.105-115
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• 2016

In the process of exploring sustainable development, major cities in China are expanding metro systems as a strategy to reduce the negative environmental and social consequences of fast-paced motorization. A metro station is not only a transportation node, but also a place where diverse activities can be performed. Therefore, the realization of the spatial potential for human interaction is the essence of the strategy for integrated development in metro station areas. For this paper, 10 well-developed metro stations in Central Shanghai were selected to investigate the correlation between accessibility and spatial performance in station areas. The spatial performance in station areas is significantly affected by metro configuration. However, both vehicle and pedestrian accessibility show weak influence on spatial performance. A synergistic model was then developed to provide quantitative support for transit-oriented development in metro station areas.

• 디지털산업정보학회논문지
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• 제7권4호
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• pp.47-55
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• 2011

In this paper, the management system for a bicycle station using 900 MHz RFID technology has been developed. Based on the several reasons such as environmental pollution, high oil prices, and the government's eco-friendly policies, a bicycle usage is increasing nowadays. Accordingly, a need for bicycle parking spaces has already been emerging and increasing around a bicycle station. But most of the bicycle parking system are operated by manually, and it causes somewhat inefficient. Therefore, this paper suggests an unmanned bicycle station using RFID technology. The proposed system is supported by the mobile applications that are operated in the smart phones, and which gives the real-time access to the information of bicycle station. The proposed system yields owners of bicycle owners the convenience and efficiency of the station management in order to maximize the function of the bicycle stations.