• Proceedings of the Korean Society of Agricultural Engineers Conference
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• 2002.10a
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• pp.409-412
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• 2002

In this presentation, the methods that is appropriate to remediate the farmland contaminated by petroleum hydrocarbon was considered using the case histories of the abroad. As a result of a consideration, most remediation procedures were based risk assessment and management, risk-based procedure. It is also useful to use natural attenuation mechanism to remediate petroleum-contaminated sites. However, more research efforts are demanded for developing a cost-effective and efficient technologies.

• 한국항공운항학회:학술대회논문집
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• 2005.11a
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• pp.132-135
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• 2005

이체 쿼터니언(dual quaternion)은 선형 미분방정식으로 계산하는 쿼터니언을 회전운동과 병진운동을 동시에 취급하는 이체수(dual numbers)체계로 표현한 형태이다. 성능향상을 위해 이체 쿼터니언을 관성항법 알고리즘에 적용시킨 논문이 새로이 소개되었다. 기존 알고리즘과 새로운 알고리즘을 MATLAB으로 시뮬레이터를 작성하였으며, 정확도와 실행 속도 측면에서 성능을 평가하고자 한다.

• The Transactions of the Korean Institute of Electrical Engineers D
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• v.51 no.4
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• pp.144-151
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• 2002

This paper presents a fault-tolerant duplex architecture to build a high-reliability microcontroller using commercial VLSI processors. The architecture supports fail-silence under all single-failure situations and facilitates recovery from transient failures. The paper implements the duplex architecture using two Motorola MC68360 processors and evaluates its fault tolerance in a real application environment.

• Proceedings of the Korea Concrete Institute Conference
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• 2000.10a
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• pp.455-460
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• 2000

Fly ash can be used as cement replacement material and can also produce the durable concrete. According to the results, the compressive strength of concrete containing fly ash is slightly lower than that of normal concrete at early ages, however, the long-term compressive strength is significantly higher beyond 90 days, and it increases the durability of concrete as well.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.311-314
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• 1999

This paper presents the design method of a repetitive controller to educe the harmonics in the output voltage waveform of the AC power supply systems. Output voltage error under the nonlinear load like a rectifier is cyclic with the same period to fundamental wave, therefore one can design the repetitive controller calculating cycle by cycle. The controller is verified mathematically and by simulations.

• Proceedings of the KIPE Conference
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• 1999.07a
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• pp.469-471
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• 1999

In this paper, the method of Space-Vector Pulse Width Modulation(SVPWM) with Fuzzy Logic Regulator(FLR) is proposed. In a conventional SVPWM, the procedures of phase transformation and choosing PWM patterns are complex. So, it should be implemented with high performance processor like Digital Signal Processor(DSP). In order to reduce a calculation burden, a proposed system adopts FLR. Using a linguistic contro strategy based on expert knowledge, FLR relieves the processor from a heavy computations. In simulations, the proposed system is validated.

• Proceedings of the KIEE Conference
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• 1999.07f
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• pp.2804-2806
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• 1999

This paper presents a voltage regulator for an AC power supply. It is designed to have the band Pass filter characteristic for the system to be free from DC-offset or sub-frequency fluctuation in the output voltage wave

• Transactions of the Korean Society of Mechanical Engineers
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• v.8 no.6
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• pp.604-609
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• 1984

본 연구에서는 동력이 작용하는 원환의 동력학적 진동해석으로부터 임계 좌굴 하중을 유도하 였다. 또한 진동 해석에서는 병진 관성 이외에 회전 관성과 전단 변형 효과를 개별적으로 고려 함으로서 두 개의 고유진동수에 관한 공식을 유도하였고 이로부터 좌굴하중을 산출하였다. 그 결과는 Timoshenko가 재료역학적 이론을 배경으로 산출한 좌굴하중과도 잘 일치함을 확인할 수 있었다.

• The Magazine of the Society of Air-Conditioning and Refrigerating Engineers of Korea
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• v.8 no.1
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• pp.10-13
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• 1979

The study for bubbling phenomena to influence heat transfer in gas - liquid contactors. The sparged contactor is gaining importance for gas-liquid chemical reactions. In this paper, correlations between Reynolds number and heat transfer coefficient were studied and experimental expressions were also obtained over broth of areas, namely, laminar area and turbulent area respectively.

• Journal of Korean Society of Industrial and Systems Engineering
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• v.15 no.26
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• pp.1-11
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• 1992

Material Handling equipments such as hoists, cranes, storage and retrieval machines, gantry robots and conveyors are carrying out more important tasks in material flow automation field. This paper is concerned with the characteristic and the position of this industry, and presents the status of the business world scale, supply and demmand. import and export transition, and directing posts of the profits. Also it gives productivity security and activity.