• 상하수도학회지
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• 제25권6호
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• pp.847-859
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• 2011

This paper presents an alarm system for the integrated monitoring and control station of waterworks in Daegu City. An alarm system informs the operator or other responsible individuals about the abnormality in the process so that an appropriate action can be taken. In practice, operators receive far more false and nuisance alarms than valid and useful alarms. Too many false and nuisance alarms can distract the operator from operating the plant, and thus critical alarms may be ignored. This problem can lead to the point that the operator no longer trusts the alarms or even shuts down the whole monitoring system. This paper proposes an efficient method to reduce false and nuisance alarms by prioritizing every fault using the Fault Tree Analysis (FTA) technique. The effectiveness of the proposed method is evaluated with a set of computer simulation under various faulty conditions.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.445-450
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• 2004

A railway station is a place where the railway operator concretize his marketing policy to meet the internal and external changes of a railway. Hence the analysis on the railway stations could give some useful information on the conditions which influence the shape of railway station. The purpose of this study is to analyze the development of Japanese railway stations. This study shows that the influencing factors on the shape of Japanese railway stations are as follows: invitation of investment from outside the japanese railway, necessity to define measures against the cut off the urban fabric by the railway facilities, profitability of the railway operator by the creation of subsidiary business, integration of administrative or public function into the station building. And the future of Japanese railway stations is now preparing by the policies on the accessibility and commodity of users and by the research projects on the environmental quality, user satisfaction.

• 대한전기학회논문지:시스템및제어부문D
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• 제52권5호
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• pp.283-289
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• 2003

This paper proposes an expert system which can determine automatically the shunting routes corresponding to the given shunting works by considering totally the train operating environments in the station. The expert system proposes the multiple shunting routes with priority of selection based on heuristic search strategy. Accordingly, system operator can select a shunting route with the safety and efficiency among the those shunting routes. The expert system consists of a main inference engine and a sub inference engine. The main inference engine determines the shunting routes with selection priority using the segment routes obtained from the sub inference engine. The heuristic rules are extracted from operating knowledges of the veteran route operator and station topology. It is implemented in C computer language for the purpose of the implementation of the inference engine using the dynamic memory allocation technique. And, the validity of the builted expert system is proved by a test case for the model station.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2004년도 춘계학술대회 논문집
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• pp.380-385
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• 2004

Railway stations are functional buildings. Their primarily role is to help passengers or freights complete their trip safely, easily, comfortably, and to improve the railway operating system. However, some urban stations are lately taking the form of what is called a station complex, and some regional stations are being constructed together with local public facilities. Roles of railway station are changing. Therefore, meeting user, railway operator, local resident, and government needs, roles of railway station would include multi-functional complex, high quality terminal, community center.

• 한국컴퓨터정보학회논문지
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• 제16권4호
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• pp.225-233
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• 2011

본 논문에서는 다양한 전장 상황에서 무인지상로봇의 효율적인 운용을 위한 통제장치와 지상로봇의 개발 방법을 제안 한다. 제안하는 통제장치의 활용을 통해 지상로봇을 운용자가 원하는 장소로의 이동 또는 지상로봇에 탑재된 다양한 임무장비의 활용을 통해 부여된 임무를 수행하는 것이 가능하다. 제안하는 통제장치는 햅틱 장치를 이용하여 입력된 운용자의 지상로봇 플랫폼 및 임무장비 제어신호를 전송하여 원격에서 무인지상로봇의 동작을 정밀하게 제어하기 위한 시스템이다. 통제장치는 운용자의 입력을 받는 햅틱 장치, 무인지상로봇의 운용 상태를 확인할 수 있는 전시장치, 내/외부 데이터를 처리하는 정보처리장치 등으로 구성된다. 또한 통제장치를 통해 부여받은 임무를 수행하는 지상로봇은 항법처리 컴퓨터, 차량 플랫폼, 장애물 회피 컴퓨터, 통합주행 컴퓨터로 구성한다. 본 논문에서 제안하는 방법을 통해 실 개발된 통제장치를 통해 다수의 지상로봇을 운용하였으며 이를 통해 지상로봇과 통제장치의 효율성을 검증하였다.

• 대한산업공학회지
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• 제34권2호
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• pp.235-245
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• 2008

The purpose of this paper is to develop a genetic algorithm to determine the optimal locations of base stations and relay stations in Wibro MMR Network. Various issues related to the genetic algorithm such as solution representation, selection method, crossover operator, mutation operator, and a heuristic method for improving the quality of solutions are presented. The computational results are presented for determining optimal parameters for the genetic algorithm, and show the convergence of the genetic algorithm.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2006년도 심포지엄 논문집 정보 및 제어부문
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• pp.285-287
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• 2006

• 한국정보과학회논문지:정보통신
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• 제37권4호
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• pp.312-316
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• 2010

본 논문에서는 기지국 채널 자원을 MNO(Mobile Network Operator)와 MVNO(Mobile Virtual Network Operator)가 공유할 경우 사업자들에게 채널 자원을 공정하고 효율적으로 할당하기 위한 게임 이론적 모델을 제안한다. 제안 모델은 협상(Bargaining) 게임 이론을 이용하며 MNO와 MVNO의 입력 부하를 고려하여 이들 사이의 기지국 채널 자원을 할당한다. 제안 기법은 사업자별 입력 부하가 비대칭적인 경우 입력 부하가 낮은 사업자보다 입력 부하가 높은 사업자에게 보다 많은 양의 채널을 할당하여 기지국의 채널 이용율을 증가시키며 또한 한 사업자의 과도한 입력 부하로 인해 타 사업자의 서비스 품질이 저하되는 것을 방지한다.

• Journal of Astronomy and Space Sciences
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• 제38권1호
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• pp.65-82
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• 2021

For the vast majority of geostationary satellites currently in orbit, station keeping activities including orbit determination and maneuver planning and execution are ground-directed and dependent on the availability of ground-based satellite control personnel and facilities. However, a requirement linked to satellite autonomy and survivability in cases of interrupted ground support is often one of the stipulated provisions on the satellite platform design. It is especially important for a geostationary military-purposed satellite to remain within its designated orbital window, in order to provide reliable uninterrupted telecommunications services, in the absence of ground-based resources due to warfare or other disasters. In this paper we investigate factors affecting the robustness of a geostationary satellite's orbit in terms of the maximum duration the satellite's station keeping window can be maintained without ground intervention. By comparing simulations of orbit evolution, given different initial conditions and operations strategies, a variation of parameters study has been performed and we have analyzed which factors the duration is most sensitive to. This also provides valuable insights into which factors may be worth controlling by a military or civilian geostationary satellite operator. Our simulations show that the most beneficial factor for maximizing the time a satellite will remain in the station keeping window is the operational practice of pre-emptively loading East-West station keeping maneuvers for automatic execution on board the satellite should ground control capability be lost. The second most beneficial factor is using short station keeping maneuver cycle durations.

• 한국CDE학회지
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• 제11권2호
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• pp.15-22
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• 2005

Presented in the paper is an approach to developing an intelligent mold shop as a means to overcome the difficulties faced by mold-makers due to skill shortages and increased global competition. A machine shop where as much as of the human skills are replaced by a set of intelligent systems is called an intelligent machine shop, and an intelligent mold-making machine shop is called an intelligent mold shop(MS). By analyzing the contents of operator's skill. three intelligent S/W stations have been designed: Technical Data Processing(TDP) Station, Loading Schedule Station, and Real-time Monitoring Station. A detailed architecture of the TDP station is described, and measures of effectiveness of IMS are elaborated.