• Journal of Information Technology Applications and Management
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• 제12권4호
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• pp.133-155
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• 2005

This Paper makes an attempt to suggest a process of automatically generating application software based on the Entity-Relationship model 1. The designer develops an E-R model of an real-world system. 2. The designer inputs the entity and relationship types, and attributes shown in the E-R model, and also the basic operations of the application system to the software generator. 3. The application generator produces database schema and link information between application programs, and then automatically generates a stereo-type application system. In order for the automated application generator to build the application system in a systematic way, four basic program generation rules have been suggested. A set of computer programs have been developed in order to show the applicability of the automated software generation process suggested in this paper. By following each rule with the generator, the designer can build an application in an efficient manner compared with traditional (manual programming) approaches. It has been demonstrated from the case study that the idea of applying an automated generator in systems development based upon the E-R model is feasible.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2010년도 춘계학술대회 논문집
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• pp.225-226
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• 2010

ISO 22266-1 issued in May 2009 provides guidelines for applying shaft torsional vibration criteria, under normal operating conditions, for the coupled shaft system and long blades of a turbine generator set. In case that a turbine generator vendor do not meet the separation margin of torsional natural frequencies in the technical specifications of the purchaser, this standard can present the reasonable and objective criteria about torsional vibration which both purchaser and supplier can agree on, while ensuring the integrity of turbine generator. This paper describes the application case of ISO 22266-1 for the establishment of torsinal vibration criteria under retrofitting the turbine generator of 'U' nuclear power plant.

• 설비공학논문집
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• 제14권2호
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• pp.127-133
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• 2002

The objectives of this paper are to develop an advanced GAX cycle named HGAX (Hybrid Generator Absorber heat exchanger) cycle, and to study the effect of key parameters on the cycle performance and the hot-water temperature from the condenser. New types of the HGAX cycle are developed by adding a compressor between the generator and the condenser- Type C (performance improvement and reduction of the generator temperature) and Type D (Hot-water temperature application). The solution temperature in the generator outlet is reduced to 168$^{\circ}C$ with the COP improvement of 19% compared to the standard GAX cycle. The hot-water temperature from the condenser is raised to 106$^{\circ}C$ for panel heating (Ondol heating) application.

• 한국정보과학회:학술대회논문집
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• 한국정보과학회 2000년도 가을 학술발표논문집 Vol.27 No.2 (3)
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• pp.132-134
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• 2000

무선 인터넷의 급속한 발전과 더불어 모바일 인터넷에서 요구되는 기능이 점점 다양화되어 가고 있다. 특히 WAP)Wireless Application Protocol)상에서 지원되는 Push 서비스의 요구가 늘어나고 있다. 본 논문에서는 WAP상에서 사용하는 Push message의 보다 쉬운 구현을 위해 Push 서비스의 구조와 동작 원리를 이해하고 Push Content Generator의 설계에 대해 기술한다.

• 정보기술응용연구
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• 제3권4호
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• pp.63-92
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• 2001

1970대 이후 CASE 도구들은 꾸준히 발전되어 오고 활용은 보편화되고 있다. 많은 CASE 도구들은 보다 확대된 기능을 제공하기 위하여 통합되고 연계되고 있다. 한편 E-R 모델은 모델링 도구로서 널리 사용되고 있으며 대부분의 CASE 도구들이 E-R 모델을 지원하고 있다. 본 연구에서는E-R 모델에 내재한 여러 가지 특성과 응용시스템의 기본 요소들 사이에 관계를 설정하고 이를 이용하여 응용시스템을 자동적으로 생성할 수 있는 방법을 제시한다. 먼저 E-R 모델로부터 일정한 규칙에 의해 업무 프로그램, 프로그램간의 링크, 지속적 데이터 등으로 구성된 정형적 응용시스템이 생성된다. 정형적 시스템은 이용자를 위한 인터페이스 설계를 거쳐 최종적인 응용시스템으로 생성된다. 본 연구에서는 제안된 자동생성과정의 실현가능성을 가상의 시스템을 대상으로 검증해 본다. 본 연구에서 제안된 응용시스템의 자동생성 방안은 CASE 도구들의 모델링 기능과 코드 생성 기능을 연계하고 통합할 수 있는 하나의 대안을 제시할 것으로 기대된다. 동시에 종래에 데이터모델링 도구로서 주로 인식되어 온 E-R 모델에 관한 연구를 응용시스템 전체에 대한 모델링의 관점으로 확대할 수 있을 것으로 기대된다.

• 전기학회논문지P
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• 제64권1호
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• pp.35-40
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• 2015

Generators are the most complex and expensive single element in a power system. The generator protection relays should to minimize damage during fault states and must be designed for maximum reliability. A conventional CDR(Current Differential Relaying) technique based on DFT(Discrete Fourier Transform) filter have the disadvantages that the time information can lead to loss in the process of converting the signal from the time domain to the frequency domain. A WT(Wavelet transform) and WT analysis is known that it is possible with the local analysis of the fault and transient signal. In this paper, to overcome the defects in the DFT process, an application of WT for fault detection of generator is presented. This paper describes an selection of mother Wavelet to detect faults of generator. Using collected data from the fault simulation with ATPdraw, we analyzed the several mother Wavelet through the course of MLD(multi-level decomposition) using MATLAB software. Finally, it can be seen that the proposed technique using detail coefficient of Daubechies level 2 which can be fault discriminant of generator.

• Journal of Electrical Engineering and Technology
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• 제8권6호
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• pp.1371-1379
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• 2013

Application of induction machines in wind turbine driven generators is a good alternative due to their good characteristics such as efficiency, reliability and low cost. Nevertheless, when isolated operation is required, the application of external capacitive bank, connected to the stator windings, to provide self-excitation results in a rather complex analysis. This paper presents an analysis of self-excited induction generator connected to a load either directly or by an intermediate of a power converter. At first a dynamic model of the induction generator accounting for magnetic saturation is developed. Then a number of balanced and unbalanced capacitors, passive and active loads are verified. Experimental results obtained from laboratory tests are compared to those simulated; the two are shown to be in good agreement.

• 대한기계학회논문집B
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• 제31권8호
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• pp.688-693
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• 2007

To improve aerodynamic efficiency of the Smart Un-manned Aerial Vehicle(SUAV), vortex generator was applied along the wing upper surface during SUAV tests. Vortex generator, initially used in TR-S2 configuration to enhance lift characteristic, increased lift coefficient. Meanwhile vortex generator produced excessive drag and eventually reduced lift-to-drag ratio. To examine the effect of vortex generator's height, three different heights of vortex generator were used for various SUAV configuration. Vortex generator of 3mm height used in TR-S4 configuration produced 3.1% increase in maximum lift coefficient and 1.5% reduction in lift-to-drag ratio.

• 전기학회논문지P
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• 제63권4호
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• pp.322-326
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• 2014

Recently, the LOE(loss of excitation) incidents are occurred in domestic synchronous generator frequently, the synchronous generator protection system has been much attention for the LOE protection of the incidents that threats synchronous generators and power systems. This paper was showed the characteristics and practices of distance relay that widely used LOE protection relaying in generator. Firstly, the operating characteristics and the impedance locus for LOE of the generator protection were introduced. Even if the conventional simulation program is used for modeling, but it is difficult to implement a LOE modeling and simulation of synchronous generator. So, the LOE relay operation data collected from thermal power plant and nuclear power plant in real fields were analyzed. By reviewing the applications of GE Mho relays, the reliability of LOE for synchronous generator protection in domestic were improved.

• 전기학회논문지
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• 제58권7호
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• pp.1287-1293
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• 2009

This paper presents an application of Harmony Search (HM) meta-heuristic optimization algorithm for optimal operation of microgrid system. The microgrid system considered in this paper consists of a wind turbine, a diesel generator, and a fuel cell. An one day load profile which divided 20 minute data and wind resource for wind turbine generator were used for the study. In optimization, the HS algorithm is used for solving the problem of microgrid system operation which a various generation resources are available to meet the customer load demand with minimum operating cost. The application of HS algorithm to optimal operation of microgrid proves its effectiveness to determine optimally the generating resources without any differences of load mismatch and having its nature of fast convergency time as compared to other optimization method.