• Proceedings of the KIEE Conference
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• 2000.07a
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• pp.125-127
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• 2000

Multiple faults are hard to diagnose correctly because the operation of circuit breakers tripped by former fault changes the topology of power systems. The information including operating time of actuated relays and tripped circuit breakers is used for considering changes of the network topology in fault section diagnosis. This paper presents a method for fault section diagnosis using a set of matrices which represent changes of the network topology due to operation of circuit breakers. The proposed method uses fuzzy relation to cope with the unavoidable uncertainties imposed on fault section diagnosis of power systems. The inference executed by the proposed matrices provides the fault section candidates in the form of a matrix made up of the degree of membership. Experimental studies for real power systems reveal usefulness of the proposed technique to diagnose multiple faults.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.653-657
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• 2005

The commercial contract was made firstly in the world for one set of high temperature superconducting(HTS) cable system between buyer, Korea Electric Power Research Institute and seller, Sumitomo Electric Industries, Ltd. in August 2004. After fabrication, test and examination, the HTS cable system will be installed at the KEPRI's test field in Gochang, Jeonbuk province from the time of July 2005. KEPRI is preparing measurement and test facilities for field test of the HTS cable system and carrying out researches into the design and construction of superconducting cable test building, evaluation of cooling performance, measurement of AC loss, analysis of the quench phenomena due to excess current and means of linking the HTS cable system to the existing electric power supplying system. The constitution of, the method to install and the plan of test operation of the HTS cable system will be presented in this paper.

• Proceedings of the Korean Society of Precision Engineering Conference
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• 1996.04a
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• pp.388-392
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• 1996

Orbit Determination is process of obtaining values of those parameter which completely specify the motion of an orbiting body through space, based on a set of observation of the body. For the narrow land of Korea, the ground tracking system has very limited time of operation. In this connection the use of GPS for orbit determination has advantage of full autonomy on the ground station. It would be more powerful economical method for near-earth satellites. Therfore we have better to pay attention to the research of satellites of orbit determination by use of GPS. So in this research, we studied themotion of the satellites with estimation using GPS. As a result, the result of computer simulation show that good convergence and indicated effective for real operation.

• Journal of Advanced Marine Engineering and Technology
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• v.36 no.1
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• pp.141-148
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• 2012

The power system of leisure ship has a character of stand-alone type, so it continuously checks the usable power. Especially, the leisure ship using renewable energy needs to adjust the power consumption of loads according to the usable power. Also, the important loads of leisure ship are different by operation mode. However, current power management system doesnot consider such character. This paper studied load management system of the SPMS(Smart Power Management System) and composed using the smart plug. The SPMS controls the loads depending on a user's pattern and character through variable priority number control. This control algorithm was verified through simulation of assumed user and situation using LabVIEW.

• 제어로봇시스템학회:학술대회논문집
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• 1992.10a
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• pp.880-886
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• 1992

There has been continuous effort to achieve total automation of the power plants. But due to complexity, nonlinearities and time-varying properties of the system, no success has been reported if conventional and/or modern control theories are applied. In spite of this, the start-up and shutdown operations are successfully performed by skilled human operators who are able to utilize a great wealth of knowledge and past experiences. In this paper, in order to automate the shutdown operation of power plants, it is proposed that the operation be performed by a more efficient method than the current used, through dividing the total process into several subprocesses, introducing checkpoints, and using fuzzy logic. For this, fuzzy logic controllers and fuzzy decision-makers are designed and the validity is shown by simulation via a set of piecewise continuous shutdown models.

• Proceedings of the IEEK Conference
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• 2001.06b
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• pp.105-108
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• 2001

4 32-bit RISC core is designed for embedded application and DSP. This processor offers low power consumption by fully static operation and compact code size by efficient instruction set. Processor performance is improved by wing conditional instruction execution, block data transfer instruction, multiplication instruction, bunked register file structure. To support compact code size of embedded application, It is capable cf executing both 16-bit instructions and 32-bit instruction through mixed mode instruction conversion Furthermore, for fast MAC operation for DSP applications, the processor has a dedicated hardware multiplier, which can complete a 32-bit by 32-bit integer multiplication within seven clock cycles. These result in high instruction throughput and real-time interrupt response. This chip is implemented with 0.35${\mu}{\textrm}{m}$, 4- metal CMOS technology and consists of about 50K gate equivalents.

• 연구논문집
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• s.30
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• pp.67-77
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• 2000

This study was performed to investigate the characteristics and performance of model Decanter for separating swine wastewater to solid and liquid which is slurry state with 12.6% TS. Swine wastewater of the slurry tank was pumped into model Decanter which capacity was $2m^3$/hr in 10% TS Slurry inside of bowl was separated to solid-liquid by centrifugal acceleration. Sampling was done in the section of slurry feed pipe, supernatant outflow pipe, cake discharge pipe. After solid-liquid separation TS, $COD_cr$ and slurry volume reduction effect represented 38%, 40%, 19.6% respectively. Relation factor of model Decanter operation slurry concentration, optimum retention time of slurry, overflow velocity of supernatant, supernatant concentration, sludge removal rate etc. Optimal operation conditions can be set and evaluated efficiency based on the experimental results in the case of Decanter adopted for solid-liquid separation in highly concentrated swine wastewater.

• Journal of Applied Reliability
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• v.17 no.2
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• pp.150-158
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• 2017

Purpose: The RAM objective is a very important factor that has a great effect on the improvement of the operation ration during the operation maintenance and the reduction of the life cycle cost. It is used as a design criterion during the system development, and its sufficiency should be evaluated during its test evaluation. Method: This study analyzed the cases related to RAM objective setting and suggested the improvement measures. Result: The base data for RAM objective is OMS/MP, which needs to be drawn up under the supervision of the requirement military, and a high-accuracy operating availability should be set through ALDT calculation which reflects the military logistics support environment. In addition, data collection necessary for RAM objective and RAM analysis should be made by supplementing the input data of DELIIS. Conclusion: This study suggests improvement of RAM objective considering for the weapon system.

• Proceedings of the KSR Conference
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• 2002.05a
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• pp.135-141
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• 2002

Recently, in the metro railways, researches on the skip-stop operation and development of the double deck train-set are active, which is to improve the service quality through reducing the passenger travel time and suppling seating service. Constructing new line or reforming the existent line needs huge amount of budget. Therefore, previous to start these large scale projects, scrutiny on benefit improvement, cost reduction and those optimal trade-off is indispensable. In this paper, a quantitative analysis to determine the optimal train service patterns and train-sets necessary is proposed, under the skip-stop operation condition in the metro railways. The analysis models are formulated in mathematical programming model, and tested validity using the LINGO 7.0.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.15 no.11
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• pp.937-942
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• 2003

In the present study, low-temperature low-pressure refrigerant storage method is proposed to achieve higher cooling capacity during a short period of time than that of a compressor in steady operation. Experimental apparatus was designed and set up to analyze the performance of the new-conceptual cooling system. Two reservoirs for sequential storage of refrigerant were used in the cooling system. Several on/off solenoid valves were installed for control of refrigerant flow. From the experimental results, the initial rapid cooling by low temperature low-pressure refrigerant storage method was ascertained for successful operation. This rapid cooling methodology shall be useful for other low-capacity refrigeration system.