• Journal of Mechanical Science and Technology
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• 제16권10호
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• pp.1287-1295
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• 2002

In this work, the fuel economy of a parallel hybrid electric vehicle is investigated. A vehicle control algorithm which yields operating points where operational cost of HEV is minimal is suggested. The operational cost of HEV is decided considering both the cost of fossil fuel consumed by an engine and the cost of electricity consumed by an electric motor. A procedure for obtaining the operating points of minimal fuel consumption is introduced. Simulations are carried out for 3 variations of HEV and the results are compared to the fuel economy of a conventional vehicle in order to investigate the effect of hybridization. Simulation results show that HEV with the vehicle control algorithm suggested in this work has a fuel economy 45% better than the conventional vehicle if braking energy is recuperated fully by regeneration and idling of the engine is eliminated. The vehicle modification is also investigated to obtain the target fuel economy set in PNGV program.

• 한국해양공학회지
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• 제11권1호
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• pp.106-112
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• 1997

This paper describes the development of a test-bed vehicle named TAUV which can be a tool to evaluate the performance of a new control algorithm, operating software and the characteristics of sensors for an AUV. The test-bed AUV is designed to operate at depth of ten meters. It is 19.5kg in air and neural buoyancy in water and the dimension is $535{\times}400{\times}102mm$. TAUV is equipped with a magnetic compass, a biazial inclinometer, a rate gyro, a pressure sensor and an altitude sonae for measuring the motion of the vehicle. Two horizoltal thursters and two elevators are installed in order to propel and control the AUV. This paper persents the control system of TAUV which is based on a 16 bit single-chip microprocessor, 80c196kc, and the software architecture for the operating system. Experimental results are included to verify the performance of the TAUV.

• 설비공학논문집
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• 제18권12호
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• pp.964-970
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• 2006

Vapor compression refrigerators have much critical variables such as the controls of temperature and pressure switches, control durations and operating hours of electronic valves. This study compares and analyzes the data which is obtained from system controlling of the evaporation temperatures which are generally used in automatic pump down operating systems. Through this study, the automatic evaporation control operation system will be more ideal for the system to keep the proper temperature distribution depending on the purpose of evaporation side. The automatic pump down control operation is more appropriate for the system to aim at the effective use of evaporation side without using the temperature difference. And this test will be proved that the changes at the low pressure side didn't have significant impacts on the high pressure side.

• Journal of Advanced Marine Engineering and Technology
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• 제29권2호
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• pp.225-235
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• 2005

In this Paper, it was designed the GA-fuzzy controller of a Thyristor Controlled Series Capacitor(TCSC) for enhancement of power system stability. The newly designed controller of TCSC was designed to overcome the nonlinearity such as operating point change of power system as well as to respond to disturbances as uncertainties of line parameters and line fault. So, fuzzy controller by intelligent control theory was used for it. And the fuzzy controller was optimized from a genetic algorithm for complements the demerit such as the difficulty of the component selection of fuzzy controller namely. scaling factor. membership function and control rules. Nonlinear simulation results show that the proposed control technique is superior to conventional PSS in dynamic responses over the wide range of operating conditions and is convinced robustness and reliableness in view of structure.

• 한국항행학회논문지
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• 제28권2호
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• pp.210-215
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• 2024

선박의 자동화 수준이 높아지고 자율운항선박의 개발에 따라 선박의 IPMS (integrated platform management system)는 다양한 운영체제로 통제되는 개별 장비들을 통합하고 다량의 데이터를 실시간으로 처리해야 한다. 이러한 상황에서 데이터 처리를 위해 DDS (data distribution service) 미들웨어 기반 선박 IPMS 시뮬레이터를 개발하고 성능을 평가하였다. 이종 운영체제로 동작하고 있는 신호입출력장치와 IPMS 서버에서 초당 1,000개의 토픽을 비동기로 발간하고 구독한 시뮬레이션을 수행하였으며, 초기 4초 동안 일부 토픽의 누락을 제외하고는 오류 없이 데이터를 수신하였다. 개발된 시뮬레이터는 실제 선박에서 DDS를 이용하여 다른 제어체계를 통합할 수 있음을 보여준다.

• 정보보호학회논문지
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• 제14권3호
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• pp.3-12
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• 2004

보안운영체제는 운영체제에 내재된 보안상의 결함으로 인하여 발생할 수 있는 각종 해킹으로부터 시스템을 보호하기 위해서 기존 운영체제에 다양한 보안기능을 추가한 운영체제이다. 보안운영체제는 시스템 보안을 목적으로 고안되었으나 전체 시스템의 안전을 위해서는 네트워크 측면에서의 보안이 필수적이다. 이를 위해서 IPsec이나 SSL과 같은 네트워크 보안 프로토콜들이 개발되어 사용되고 있으나 정책이나 키 관리에 많은 주의를 필요로 하고 보안운영체제의 특성을 반영하기 어렵다. 본 논문에서는 보안운영체제 사이에서 안전한 통신을 제공하기 위한 간단한 신뢰채널 메커니즘을 소개한다. 본 신뢰채널은 네트워크 트래픽에 대해 기밀성과 인증 서비스를 제공하며, 보안운영체제에 사용되는 특정 보안정보를 전달할 수 있는 구조를 가진다. IP 계층의 커널 수준에서 구현된 신뢰채널은 단순한 처리구조를 통하여 신뢰채널 처리과정에서 발생할 수 있는 오버헤드를 줄일 수 있다.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2003년도 춘계전력전자학술대회 논문집(1)
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• pp.327-331
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• 2003

This paper proposes a novel ZVZCS-PWM Boost Converter. It enables the main switch to be turned on and off with both zero voltage and zero current and the auxiliary switch to be turned on and off with ZCS, the rectify diode to be turned on and off with ZVS. Moreover, this converter is suitable for not on]y minority carrier device but also majority carrier device. The auxiliary resonant circuit of the proposed boost converter is placed out the main power path, therefore, there are no voltage/current stresses on the main switch and diode. The operation of the proposed boost converter is explained and analyzed theoretical and experimentally, from a prototype operating at 100kHz, with an input voltage rated at 50V.

• Ocean Systems Engineering
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• 제8권2호
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• pp.201-221
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• 2018

In this paper a comprehensive study for the structural control of Jacket platform with Magneto-Rheological (MR) damper is presented. The control is implemented as a closed loop feedback of the applied voltage in the MR Damper using fuzzy logic. Nine cases of combinations with MR damper are presented to complete the work. The selection of the MR damper (RD 1005-3) is based on the operating parameters (i.e., the range of frequency and displacement). Bingham model is used to obtain the control forces. The damping co-efficient of the model is obtained using empirical relationship between the voltage in the MR damper and input velocity from the structural members. The force acting on the structure is obtained from Morison equation using P-M spectrum. The results show that the reliable control was obtained when there was a continuous connection of multiple MR dampers with the lower levels of the structure. Independent MR dampers at different levels provided control within a range, while the MR dampers placed at alternate positions gave very high control.

• Corrosion Science and Technology
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• 제9권4호
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• pp.159-163
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• 2010

Precise coating weight control is very important issue on quality and minimizing operating costs on continuous galvanizing line. These days, many steel making companies are having a new understanding of cost importance by rise raw material prices and customer's requirement for cost reduction. Dongbu steel also meets these situations and decided to develop the technologies. Dongbu Steel developed Integrated coating weight control system jointly with Objective Control Ltd. and installed 2CGL and 4CGL. Several technological functions were developed and realized to achieve true hands-off operation and maximum cost benefit by combining model-based preset and dynamic prediction models. We also installed it on 1 CGL on April, 2008. This paper will present the interface, functions and application result of the integrated coating weight control system including Zn saving and coating weight uniformity.

• Fisheries and Aquatic Sciences
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• 제5권1호
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• pp.48-53
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• 2002

The HACCP (hazard analysis critical control point) concept becomes an important aspect of Good Manufacturing Practices (GMP) in safe food production. The HACCP plan was developed with food safety objective. The authors already carried out hazards analysis on Changran Jeotgal manufacturing process in a previous report. In this study we developed a HACCP plan on the manufacturing process of Changran Jeotgal. We could decide two CCPs those were salt concentration and eliminations of foreign materials before packaging. Foreign materials should be certainly checked out with laser detector just before packaging. Salt should be maintained more than $8\%$ to inhibit pathogenic bacteria in end product. On the Jeotgal process free water is removed after salting and Jeotgal is seasoned with several subsidiary materials such as com syrup. In result end products have $8\%$ salt with water activity 0.82. Most bacteria are inhibited but some can live in this condition. Materials on the working may be contaminate by pathogens, chemicals or physical hazards. It will be decreased by SSOP (standard sanitary operating program). The SSOP needed in Jeotgal plants is nearly same as other general food manufacturing plants but essential to fulfill HACCP program.