• The Transactions of the Korean Institute of Electrical Engineers P
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• v.60 no.4
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• pp.175-180
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• 2011

A large AC generator is an important component of the power system. It is a need for research of AC generator protection relay for the next-generation ECMS and an efficient operation of protection control system. However, most of protection and control systems used in power plants have been still imported as turn-key and operated in domestic. This may cause the lack of the correct understanding on the protection systems and methods, and thus have difficulties in optimal operation. In this paper, over-excitation protection relaying is one of the protective factors in generator protection IED was presented. The cause and protection principles were dealt and, DFT-based gain compensation algorithm was adopted for the frequency measurement. The Republic of Korea 345kV modeling data by EMTP-RV was used for performance evaluation.

• Journal of Sensor Science and Technology
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• v.23 no.5
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• pp.320-325
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• 2014

Volatile flavor compounds from milk were analyzed and identified by using the analysis methods of headspace solid phase microextraction gas chromatography/mass spectrometry (HSPME-GC/MS) and electronic nose (E-Nose) system. About 30 volatile compounds were identified by HSPME-GC/MS for the fresh and off-flavor milk samples. Also, the correlation between rancidity and ageing days of milk was obtained by the aid of principal component analysis algorithm. It shows that the E-Nose system can identify the various types of milk flavor. These results imply that the analysis method based on the E-nose system can apply to the quality control of milk flavor and the rancidity.

• Proceedings of the KIEE Conference
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• 2005.07a
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• pp.199-201
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• 2005

This paper proposes a method to evaluate the TTC by considering uncertainty of weather. Impact of the contingency on the system performance could not be addressed in a deterministic way because of the random nature of the system equipment outage and the increase of outage probability according to weather condition. For this reasons, probabilistic approach is necessary to realize evaluation of TTC. This method uses a sequential MCS. In sequential simulation, the chronological behavior of the system is simulated by sampling sequence of the system operating states based on the probability distribution of the component state duration. Therefor, MCS is used to accomplish the probabilistic calculation of TTC with consideration of weather condition.

• 한국디지털정책학회:학술대회논문집
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• 2004.05a
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• pp.575-592
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• 2004

In modern dynamic management environment, there is growing recognition that? information & knowledge management systems are essential for CEO's efficient/effective decision making. As a key component to cope with this current, we suggest the management performance analysis syystem based on Knowledge Discovery in Database (KDD). The system measures management performance that is considered with both VA(Value- Added), which represents stakeholder's point of view and EVA(Economic Value-Added), which represents shareholder's point of view. The relation ship between management performance and some 80 financial ratios is analyzed, and then important financial ratios are drawn out. In analyzing the relationship, we applied KDD process which includes such as multidimensional cube, OLAP(On-Line Analytic Process), data mining and AHP(Analytic Hierarchy Process). To demonstrate the performance of the system, we conducted a case study using financial data over the 16-years from 1981 to 1996 of Korean automobile industry which is taken from database of KISF AS(Korea Investors Services Financial Analysis System).

• Journal of Korean Society of Water and Wastewater
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• v.28 no.1
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• pp.135-142
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• 2014

The performance of inorganic sludge separation system is evaluated. Anaerobic digester effluent sludge is used for feed sludge of this system and hydrocyclone is used for inorganic sludge separation. For phosphorus removal and recovery $MgCl_2$ is pumped into MAP growth tank, a component of inorganic sludge separation system. Using this system inorganic sludge which contained less than 40 % of organic matter can be discharged stably and the maximum amount of separated inorganic sludge is 13.4 % of influent sludge based on dry solid. The amount of phosphorus recovered as MAP(as P) is 16.7 % to influent T-P.

• Journal of Industrial Technology
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• v.26 no.B
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• pp.135-144
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• 2006

The significance of hydro-power plant is increasing in its public roles such as flood control and water supply as well as electric power production. Even if high level of reliability in facility operation is required, no specific reliability research has been made. This specifically stems from the lack of technology and research investments. The eventual goal of this study is to secure a methodology for reliability analysis of hydro-power plant so that an appropriate decision for operation and investment can be made. Specific effort was put to develop a reliability model for water supply system within hydro-power plant. For this study, we briefly examined the overview of the hydro-power plant including the electric power generation facility system. We then discussed the facility reliability analysis methodology for hydro-power plant. Based on rigorous examination of the water supply system and components roles, we drew major failure modes for each component and examined their effects.

• Proceedings of the KIEE Conference
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• 1995.11a
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• pp.64-66
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• 1995

This paper presents a new approach to evaluate optimal basic reliability indices of electric distribution systems using genetic algorithm. The use of optimal reliability evaluation is an important aspect of distribution system planning and operation to determine adequacy reliability level of each area. In this paper, the reliability model is based on the analytical method, connecting component failure to load point outage in each section. The proposed method applies genetic algorithm to calculate the optimal values of basic reliability indices, ie. failure rate and repair time, for a load point in the power distribution system, subject to minimizing interruption cost. Test results for the model system are reported in the paper compared with a direct optimization method(gradient projection).

• 유체기계공업학회:학술대회논문집
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• 2005.12a
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• pp.759-764
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• 2005

In this paper, numerical analysis of hydrogen recycle system has been conducted in order to enhance the efficiency of automotive fuel cell. Generally, the excess hydrogen is provided in the automotive fuel cell. Since the non-reaction hydrogen reduces automotive fuel cell efficiency, reuse of the non-reaction hydrogen can be helpful to improve the fuel cell performance. In case of PEM FC, the water vapor is provided to hydrogen from the cathode so that the mixture experiences phase change depending on the changes of pressure and temperature. The internal flow of the mixture in the hydrogen recirculation system of fuel cell was investigated for real flow conditions. The variation of performance, properties and mass fractions of mixture, hydrogen and water-vapor were investigated. This study was performed based on 80KW level automotive fuel cell's recycling system.

• Proceedings of the KOSOMBE Conference
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• v.1998 no.11
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• pp.251-252
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• 1998

Most of Electroencephalography(EEG) systems currently being used in hospitals don't support a standardized communication protocol for the exchange of orders, data and results. ASTM: E1467 protocol was proposed to expedite the EEG data exchange between different EEG systems and eventually between hospitals. In this paper, we present an Electroencephalography Information System using ASTM: E1467 protocol, with which patient registration, orders, interpretation, and review can be performed electronically. The system is designed using a component-based methodology. Most of the components are written in Visual C++ and Visual Basic. JAVA is also used to implement some components.

• Journal of Korea Technology Innovation Society
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• v.6 no.4
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• pp.551-568
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• 2003

The aircraft industry is a typical complex product system (CoPS) and one of the system integration industries. In this particular sector, industrial competitiveness is decided by technological capabilities in system level as well as subsystem level. Korea has been involved in the aircraft industry since early 1970s. Technological capability in the system level has been developed based on military aircraft production program. However, subsystem and component level capabilities have been remained less developed. In this paper, the capability building process as well as current problem; of the Korean aircraft industry have been examined. In conclusion, capability building up strategies in the Korean aircraft industry has been suggested.