• Proceedings of the Korean Institute of Navigation and Port Research Conference
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• 2006.10a
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• pp.11-18
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• 2006

Ship Pilotage is one of the most important parts in the construction and development of Shanghai International Shipping Center as it has the fundamental function for the promotion and speed-up of the ship navigation and cargo operation. Recently, Shanghai Maritime University and Shanghai Harbour Pilotage Administration Station had carried out a research project of 'Study on Ship Safety Pilotage in the Shanghai Harbour by Way of FSA (Formal Safety Assessment)'. The aim of this project is to put out some proposes of the decision-making for the improvement of the safety pilotage in Shanghai habour through the way of the FSA. Now these proposes of the decision-making have been adopted and conducted in practice and satisfactory results have been achieved. In the paper, some detailed information, methods and ideas about this research project have been introduced and explained for improving the safety pilotage in Shanghai Harbour.

• KIEE International Transactions on Power Engineering
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• v.5A no.4
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• pp.416-424
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• 2005

At present, the Korean electricity industry is undergoing restructuring and the Cost Based-generation Pool (CBP) market is being operated in preparation of a Two Way Bidding Pool (TWBP) market. In deregulated electricity industries, an integrated power market simulator is one of the tools that can be used by market participants and market operators analyzing market behaviors and studying market structures and market codes. In this regard, it is very important to develop an electricity market simulator that reflects market code providing a market operation mechanism. This paper presents the development of an integrated market simulator, called the Power Exchange Simulator (PEXSIM), which is designed to imitate the Korean electricity market considering the various features of the market operating mechanism such as uniform price and constrained on/off payment. The PEXSIM is developed in VB.NET and composed of five modules whose titles are M-SIM, P-SIM, O-SIM, T-SIM and G-SIM interfacing the Access database program. To verify the features and the performance of the PEXSIM, a small Two Way bidding market with a 12-bus system and a One Way bidding market for generator competition will be presented for the electricity market simulations using PEXSIM.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.2 no.3
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• pp.359-365
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• 1998

The portable two way radio telephone amongst GMDSS equipment in the vessel is very important portable wireless one for search and rescue in distress situation. Although the portable two way radio telephone must be equipped with in the vessel by IMO & RR, other kinds of wireless tranceivers are widely used to communicate with crew members who are separately appointed at bridge forecastle and poop in leaving or arriving at the port, passing through a narrow canal or voyaging in the foggy weather, Most of those wireless tranceivers except portable two way radio telephone are allocated at 27MHz band with PTT simplex system that makes crew members difficult to work effectively in the vessel. In this research 900MHz band FDD(frequency duplex division) tranceiver system is studied to help crew members in the vessel to communicate with themselves freely and to work easily meanwhile with simple operation. 900MHz band FDD tranceiver system uses one chip FM frontend IC to realize the miniaturization and downsizing of tranceiver and small size head set attached to helmet. The credibility of this research's result is highly evaluated by circuit analysis with computer aided simulation, and partly modified 900MHz band cordless phone circuit.

• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 1998.05a
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• pp.365-370
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• 1998

The portable two way radio telephone amongst GMDSS equipment in the vessel is very important portable wireless one for search and rescue in distress situation. Although the portable two way radio telephone must be equipped with in the vessel by IMO RR, other kinds of wireless tranceivers are widely used to communicate with crew members who are separately appointed at bridge forecastle and poop in leaving or arriving at the port, passing through a narrow canal or voyaging in the foggy weather. Most of those wireless tranceivers except portable two way radio telephone are allocated at 27MHz band with PTT simplex system that makes crew members difficult to work effectively in the vessel. In this research 900MHz band FDD(frequency duplex division) tranceiver system is studied to help crew members in the vessel to communicate with themselves freely and to work easily meanwhile with simple operation. 900MHz band FDD tranceiver system uses one chip FM frontend IC to realize the miniaturization and downsizing of tranceiver and small size head set attached to helmet. The credibility of this research's result is highly evaluated by circuit analysis with computer aided simulation. and partly modified 900MHz band cordless phone circuit.

• 제어로봇시스템학회:학술대회논문집
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• 1996.10a
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• pp.426-439
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• 1996

In this paper, we propose a simple algorithm to calculate the numbers of the passing cars by using an image processing sensor for the digital black and white images with 256 tone level. Shadow is one of the most troublesome factor in image processing. By differencing the tone level, we cannot discriminate between the body of the car and its shadow. In our proposed algorithm, the area of the shadow is excluded by recognizing the position of each traffic lane. For real-time operation and simple calculation, two lines of the tone level are extracted and the existences of cars are recognized. In the experimental application on a high-way, the recognition rate of the real-time operation is more than 94%.

• The Korean Journal of Food And Nutrition
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• v.23 no.4
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• pp.615-622
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• 2010

The present study attempted to investigate the military foodservice operation by conducting survey to foodservice managers. Surveys for managers of military foodservice operations were conducted in November, 2008 by visiting Consolidated Army Logistics School located in Daejeon during the time of training. Surveys for military foodservice officers and dietitian were sent by mail. The questionnaire was composed of the questions asking the general operation of military canteen, the self-concious specialty of military foodservice, and the needs assigning dietitian to each military unit. From the results of this study, it came up with the needs to draw up the plan to improve the foodservice specialty of canteen managers. One of the solution would assign dietitian to each military foodservice unit. Also, the facilities need to be equipped for various way of cooking to improve the satisfaction of soldiers. The results of this study would provide the data for making policy as well as arose academic interest to military foodservice.

• The Transactions of the Korean Institute of Electrical Engineers B
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• v.55 no.4
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• pp.224-230
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• 2006

The conventional way to implement a bidirectional converter with boost/buck has been to use two general purpose PWM ICs with a single supply voltage. In this case, when one direction mode is in operation, the other is disabled and the output of the error amplifier of the disabled IC may be saturated to a maximum value or zero. Therefore, during mode transition, a circuit which can disable the switching operation for a certain time interval is required making it impossible to get a seamless transition. In this paper, the limitations of the conventional 42V/14V bi-directional DC/DC converter implemented with general current mode PWM ICs with a single supply voltage are reviewed and a new current mode PWM controller circuit with a dual voltage system is proposed. The validity of the proposed circuit is investigated through simulation. and experiments.

• Proceedings of the Korean Operations and Management Science Society Conference
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• 2004.10a
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• pp.527-530
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• 2004

This paper presents an optimization formulation for resource scheduling in Critical Resource Diagramming (CRD) of production scheduling networks. A CRD network schedules units of resources against points of needs in a production network rather than the conventional approach of scheduling tasks against resource availability. This resource scheduling approach provides more effective tracking of utilization of production resources as they are assigned or 'moved' from one point of need to another. Using CRD, criticality indices can be developed for resource types in a way similar to the criticality of activities in Critical Path Method (CPM). In our supply chain model, upstreams may choose either normal operation or expedited operation in resource scheduling. Their decisions affect downstream's resource scheduling. The suggested optimization formulation models resources as CRD elements in a production two-stage supply to minimize the total operation cost

• Journal of Ship and Ocean Technology
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• v.12 no.4
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• pp.32-39
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• 2008

According to the increase of the requirement for the safety and environmental protection at sea, safety is a core design factor of maritime systems. Safety is defined as a perceived quality that determines to what extent the management, engineering and operation of a system is free of danger to life, property and the environment. There are many possible approaches in dealing with the safety of ships. The risk-based approach is one of the most systematic and reasonable way currently in design, operation and regulatory works for ship safety. This paper proposes a concept of total risk management for ship safety, and introduces a prototype system implemented based on this concept as a framework of design and operation of ships.

• The Transactions of The Korean Institute of Electrical Engineers
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• v.65 no.3
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• pp.397-403
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• 2016

Generally, an electrical distribution configuration is a radial system with one-way current in a distribution management system (DMS). All feeders in a DMS have tie-switches to make radial system. Sometimes, DMS should change a tie-switch for operation. In that case, the tie-switch has to be closed first; then a switch is opened as another tie-switch in order to prevent blackout for customers. At the moment when the tie-switch is closed, distribution system is operated in a loop state, not radial. Before the loop operation, DMS operator has to check any expected events for stable distribution system operation; and the most important event is a mis-operation of a protection relay. In addition, DMS operator should check voltage profile violation but a calculation method of section voltages had not been used. Thus, this paper proposes a calculation method of section voltages at a loop operation in a DMS. The proposed calculation algorithm is verified by Matlap Simulink.