• 한국정보기술학회 영문논문지
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• 제10권2호
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• pp.1-13
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• 2020

This paper presents an emergency brushless synchronous generator having rotating exciter status monitoring and protection functions. For monitoring the rotating exciter status, a wireless rotor status detector and a digital AVR(Automatic Voltage Regulator), which has a wireless communication capability, are proposed. The proposed rotor status detector detects temperatures of exciter armature and main field windings and input voltage and current of the main field. Therefore, it is possible to protect the generator from the over-temperature of windings and detect the exciter bridge diode fault. Furthermore, the proposed digital AVR has rotor status monitoring and protection function, and remote generator tuning, wireless group parallel operation function. So the operator can efficiently operate the generator using a smartphone from a remote area.

• Journal of Advanced Marine Engineering and Technology
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• 제26권3호
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• pp.313-319
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• 2002

Since the oil crisis in 1970, a great deal of effort has been made to develop automatic electric load sharing systems as a part of the efforts to save energy. A large scale electric generating system composes more than two generators whose characteristics may be different. When such a system is operated individually or in parallel, the lagrange multiplier's method has difficulty in achieving optimal load distribution because generators usually have the limitations of the operating range with inequality constraints. Therefore, a suitable operating mode of generators has to be decided according to the selection of the generators to meet electric power requirements at the minimum cost. In this study, a method which solves the optimal electric load distribution problem using the dynamic programming technique is proposed. This study also shows that the dynamic programming method has an advantage in dealing with the optimal load distribution problem under the limitations of the operating range with inequality constraints including generator operation mode. In this study, generator operating cost curve of second order equation by shop trial test results of diesel generators are used. The results indicate that the proposed method can be applied to the ship's electric generating system.

• 한국정보과학회논문지:소프트웨어및응용
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• 제33권9호
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• pp.810-821
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• 2006

XML 문서를 위한 컴파일러를 개발하기 위해서는 많은 노력을 필요로 하기 때문에 XML 컴파일러를 자동적으로 생성할 수 있는 방법에 대한 연구의 필요성이 증가하고 있다. XMLSchema가 표준으로 지정된 이후에 많이 사용되고 있지만, XMLSchema를 사용하는 XML 문서를 위한 XML 컴파일러 생성기에 관한 연구는 현재까지 거의 이루어지지 않았다. 본 논문에서는 속성 문법을 사용해서 XMLSchema를 사용하는 XML 문서를 위한 XML 컴파일러를 자동적으로 생성할 수 있는 방법을 소개한다. XML 컴파일러 생성기는 XMLSchema의 데이타 타입 정보와 별도로 제공되는 의미 정보를 이용해서 의미 클래스와 XML 컴파일러를 생성한다. 생성된 XML 컴파일러는 XML 문서를 파싱해서 의미 클래스의 인스턴스로 구성된 트리로 변환하고, 트리를 순회하면서 XML 문서를 사용자의 의도에 맞게 처리한다.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.2508-2513
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• 2003

This paper presents a nuclear steam generator tube inspection/maintenance robot system. The robot assists in automatic non-destructive testing and the repair of nuclear steam generator tubes welded into a thick tube sheet that caps a hemispherical or quarter-sphere plenum which is a high-radiation area. For easy carriage and installation, the robot system consists of three separable parts: a manipulator, a water-chamber entering and leaving device for the manipulator and a manipulator base pose adjusting device. A software program to control and manage the robotic system has been developed on the NT based OS to increase the usability. The software program provides a robot installation function, a robot calibration function, a managing and arranging function for the eddy-current test, a real time 3-D graphic simulation function which offers remote reality to operators and so on. The image information acquired from the camera attached to the end-effecter is used to calibrate the end-effecter pose error and the time-delayed control algorithm is applied to calculate the optimal PID gain of the position controller. The developed robotic system has been tested in the Ulchin NPP type steam generator mockup in a laboratory.

• Journal of Biosystems Engineering
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• 제24권3호
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• pp.253-258
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• 1999

This study was conducted to develop an automatic egg inspection system for detecting creaked eggs based on acoustic impulse response. This system includes a sound generator, a sound sensor with signal conditioner, and a computer. The sound generator that hit the sharp of the dull edges of an egg was constructed with a ceramic ball pendulum attached to a rotary type solenoid. The signal conditioner included a pre-amplifier and a digital signal processing (DSP) board. The parameters for distinguishing cracked and normal eggs were the area, the geometric centroid and the resonance frequency of power spectrum of the acoustic signal generated. An algorithm for on-line detection of the continuous transferring eggs was developed. The performance tests resulted with 91% success rate to separate cracked and normal eggs at the rate of 1 second per an egg.

• 전기학회논문지
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• 제60권5호
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• pp.1036-1042
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• 2011

This paper presents an algorithm that conducts automatic memory scrubbing operated by dedicated hardwares. The proposed algorithm is designed so that it can scrub entire memory in a given scrub period, while minimally affecting the execution of flight softwares. The scrub controller is constructed in a form of state machines, which have two execution modes - normal mode and burst mode. The deadline event generator and period tick generator are designed in a separate way to support the behavior of the scrub controller. The proposed controller is implemented in VHDL code to validate its applicability. A simple version of the controller is also applied to mass memory modules used in STSAT-3.

• 소성∙가공
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• 제12권3호
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• pp.194-201
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• 2003

An automatic quadrilateral mesh generator for large deformation finite element analysis such as metal forming simulation was developed. The NURBS interpolation method is used for modeling arbitrary 2-D free surface. This mesh generation technique is the modified paving algorithm, which is an advancing front technique with element-by-element resolving method for paving boundary intersection problem. The mesh density for higher analysis accuracy and less analysis time can be easily controlled with high-density points, maximum and minimum element size. A couple of application to large deformation finite element analysis is given as an example, which shows versatility and applicability of the proposed approach and the developed mesh generator for large deformation finite element analysis.

• 전기학회논문지
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• 제64권7호
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• pp.978-983
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• 2015

This paper presents Frequency Bias setting for the adequate AGC(Automatic Generator Control) operation based on the frequency response of power system in Korea. AGC frequency control recovers the frequency up to 60Hz following a primary control when the frequency suddenly drops due to a fault in power system. AGC can compensate an appropriate amount of generation by calculating ACE(Are Control Error) from the frequency deviation with the AGC frequency bias set from the actual frequency response in power systems. An appropriateness of the proposed AGC bias setting is verified through case studies employing the simulation model.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2002년도 하계학술대회 논문집 C
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• pp.1953-1955
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• 2002

An efficient automatic mesh generator suitable for the harsh model, which contains abrupt regions and thin layers, is implemented. It adopts two kinds of node placement scheme. In the beginning, the initial nodes on the boundary are generated automatically by an efficient boundary node generation scheme. And then the inner nodes are placed using nodal spacing value technique repeatedly from the initial mesh to final mesh. The effectiveness of the proposed technique is verified by a thin film micro-strip line modeling, where the final mesh contains no sliver elements.

• 한국정보처리학회:학술대회논문집
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• 한국정보처리학회 2015년도 추계학술발표대회
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• pp.1035-1037
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• 2015

현재 소프트웨어 요구사항은 전체 소프트웨어 개발 프로세스를 거쳐, 완성된 제품 인도 시 인수 기준으로 작용한다. 그러므로 이런 요구사항은 개발주기 전체에 걸친 매우 중요한 관리 수단이다. 그러나 국내 다수의 중소기업은 이러한 문서화에 시간 및 비용이 부족하여, 개발 문서의 부재 혹은 코드와 문서가 불일치한 것이 현실이다. 이 문제를 해결하기 위해, 자동 프로젝트 문서 발생기(Automatic Project Document Generator)를 제안한다. 제안한 발생기를 통해 요구사항 스펙과 소스 코드 간 동기화로 요구사항 대로 개발이 진행되는지 확인 가능하다.