• Journal of Korean Society of Water and Wastewater
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• v.25 no.6
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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.

• Proceedings of the KSR Conference
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• 2004.06a
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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.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.52 no.5
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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.

• Proceedings of the KSR Conference
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• 2004.06a
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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.

• Journal of the Korea Society of Computer and Information
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• v.16 no.4
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• pp.225-233
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• 2011

In this paper, we propose a remote control station based on the awareness of various combat field situation in order for operating multiple unmanned ground vehicles. Our remote control station is capable of sending a variety of messages designed for carrying out the skillful movement for collaborate among unmanned ground vehicles, gathering the information related with combat field situation, and completing the assigned missions which are described by operator in advance. To verify the effectiveness of our proposal, we develop the sophisticated remote control station and conduct a great many remote operating tests for multiple unmanned ground vehicles.

• Journal of Korean Institute of Industrial Engineers
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• v.34 no.2
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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.

• Proceedings of the KIEE Conference
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• 2006.04a
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• pp.285-287
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• 2006

• Journal of KIISE:Information Networking
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• v.37 no.4
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• pp.312-316
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• 2010

In this paper, we propose a game theoretic channel sharing model that allocates resources of a base station between MNO(Mobile Network Operator) and MVNO(Mobile Virtual Network Operator) in a fair and efficient manner. Considering the input traffic loads of MNO and MVNO, the proposed model uses the bargaining game theory to allocate channel resources between MNO and MNVO. When the input loads of the carriers are asymmetric, the proposed model increases the resource utilization by allocating more channel resources to the operator with high input load. In addition, the proposed model prevents the quality of service of an operator from degrading even if the input load of the other operators increases excessively.

• Journal of Astronomy and Space Sciences
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• v.38 no.1
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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.

• CDE review
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• v.11 no.2
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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.