• 전기학회논문지
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• 제67권12호
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• pp.1595-1601
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• 2018

The biggest obstacle to the commercialization of small and medium size microgrid (MG) is the reliability and economics of MG operation and maintenance. In this paper, we propose an autonomous operation method that is implemented as an application program installed in the MG operating system in emergency situations. The proposed algorithm consists of four steps of distinction, recognition, determination and control of emergency situations that can occur in MG. A fuzzy-based situation decision algorithm has been proposed to eliminate the barriers of autonomous operation in actual emergency situation such as occurrence of bad data and communication delay. In addition, countermeasures have been suggested for cases where multiple emergency situations have occurred in combination. The proposed algorithm was tested in a 500kW actual microgrid site of a university. Through the test, the validity of the proposed method and its applicability to practical MG operation are verified.

• 한국항공운항학회지
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• 제32권2호
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• pp.11-19
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• 2024

Flight simulators are crucial devices for aircraft piloting training and simulation, requiring regular inspections to maintain performance and operational quality. This study explores the development of an automated inspection system for flight simulators to automate quality inspections of control loading systems (CLS). While quality inspection of the control loading system (CLS) is essential for flight simulators, manual inspections are common practice. To address this, we developed an Auto Qualification Test Guide (Auto QTG) using artificial control logic and sensor data and applied it to the militarily simulator. Experimental results demonstrate that Auto QTG successfully automates quality inspections of CLS, enhancing accuracy and efficiency. This automated inspection system is expected to contribute to improving the operation and maintenance of flight simulators.

• 대한전기학회:학술대회논문집
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• 대한전기학회 2001년도 추계학술대회 논문집 전기기기 및 에너지변환시스템부문
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• pp.36-38
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• 2001

A neutron controls a nuclear fission in the core of a reactor. Drive system for in-core neutron detector is an equipment that drives the detector and cable to survey neutron flux in the reactor. The drive system introduced by this paper was designed for mock-up system and fabricated to drive two drivers that having a different function. The system consists of a driver assembly, a power transmission part, and cable storage part. And there is a control panel that contains PLC and inverter. This paper is going to introduce the design and certify the operation status of completed system by control panal. And we conducted the test for torque measurement.

• 대한설비공학회:학술대회논문집
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• 대한설비공학회 2006년도 하계학술발표대회 논문집
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• pp.675-680
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• 2006

Capacities of a tandem-type air-conditioner may be modulated by turning on and off of multiple compressors, and adjusting the position of a electronic expansion valve. In this study, control algorithms for compressors and a electronic expansion valve were developed by using fuzzy logics. The pressure control algorithm was also developed for the safe operation of compressors. There algorithms were implemented in a test lab and proved to be effective for the control of indoor air temperature and superheat temperature,

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1996년도 봄 학술발표회 논문집
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• pp.363-369
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• 1996

PMS(Pavement Management System) is the effective and efficient decision making system to provide pavements in an acceptable condition at the lowest life-cycle cost. As the highway system become larger, the necessity of the PMS in increasing. As of December 1995, the 3rd stage of PMS project was completed. The accomplishment of the research work can be itemized to the followings : $\bullet$ Calibration of PMS submodules (1) Pavement Condition Evaluation Model (2) Pavement Distress Prediction Model (3) Pavement Performance Prediction Mode (4) Selection of Pavement Rehabilitation Criteria (5) Optimization Technique for PMS Economic Analysis $\bullet$ Development of Computer Program to Implement PMS Logic $\bullet$ A Study to Implement the Automized Pavement Condition Survey Equipment to PMS $\bullet$ PMS Test Run $\bullet$ Development of PMS Operation Guideline $\bullet$ The 2nd Pavement Condition Survey for Long-Term Pavement Performance Monitoring.

• 한국소음진동공학회:학술대회논문집
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• 한국소음진동공학회 2002년도 추계학술대회논문집
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• pp.881-885
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• 2002

This paper presents the performance and the algorithm of a 1/3-octave band spectrum control system. The system is developed to provide various spectrums in a high intensity acoustic chamber. The required spectrum, which usually comes from launch vehicle company, starts from 25Hz band and ends 10kHz band. Automatic spectrum control system is preferred since the system requires short settling time to guarantee the safety of test objects and to reduce the amount of operating gas. The developed system adapted a PCI data-acquisition/signal-generation board installed in a personal computer to implement whole control logic. The control software used three cascade digital Butterworth filters using software. The filers are designed following ANSI S1.11 standard to implement 1/3 octave band filter bank. The graphical user interface of the system guides the user to follow standard operation procedure. The averaged control spectrum showed less than 0.05 dB in every running 1/3-octave band.

• 한국통신학회논문지
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• 제21권4호
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• pp.984-995
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• 1996

Data errors according to the various noises caused in the satellite communication links are corrected by the Viterbi decoding algorithm which has extreme error correcting capability. In this paper, we designed and implemented a convolutional encoder and Viterbi decoder ASIC which is used to encode the input data at the transmit side and correct the errors of the received data at the receive side for use in the VSAT communication system. And this chip may be used in any BPSK, QPSK, or OQPSK transmission system. The ambiguity resolver corrects PSK modem ambiguities by delaying, interting, and/or exchanging code symbol to restore their original sequence and polarity. In case of previous decoding system, ambiguity state(AS) of data is resolved by external control logic and extra redundancy data are needed to resolve AS. But, by adopting decoder proposed in this paper, As of data is resolved automatically by internal logic of decoder in case of continuous mode, and by external As line withoug extra redudancy data in burst mode case. So, decoding parts are simple in continuous mode and transmission efficiency is increased in bust mode. The features of this chip are full duplex operation with independent transmit and receive control and clocks, start/stop inputs for use in burst mode systems, loopback function to verify encoder and decoder, and internal or external control to resolve ambinguity state. For verification of the function and performance of a fabricated ASIC chip, we equiped this chip in the Central and Remote Earth Station of VSAT system, and did the performance test using the commerical INTELSAT VII under the real satellite link environmens. The results of test were demonstrated the superiority of performance.

• Journal of Electrical Engineering and Technology
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• 제4권4호
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• pp.515-520
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• 2009

According to the operating characteristics of pump applications, they should exhibit high efficiency and energy saving capabilities throughout the whole operating process. A novel efficiency optimization control strategy is presented here to meet the high efficiency demand of a variable speed Permanent Magnet Synchronous Motor (PMSM). The core of this strategy is the excellent integration of mended maximum torque to the current control algorithm, based on the losses model during the dynamic and the grade search method with changed step by fuzzy logic during the steady. The performance experiments for the control system of a variable speed high efficiency PMSM have been completed. The test results verified that the system can reliably operate with a different control strategy during dynamic and steady operation, and the system exhibits better performance when using the efficiency-optimization control.

• 디지털융복합연구
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• 제17권7호
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• pp.131-138
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• 2019

전 세계 전력 생산 에너지의 비율은 석탄이 40%, 천연가스 20%, 수력 16%, 원자력 15%, 석유 6%로 모두가 환경오염을 유발하는 에너지다. 또한 화석연료는 지구상에 자원의 편중이 심하기 때문에 가격과 공급면에서 심각한 문제를 야기한다. 이러한 문제로 화석 연료를 대체하게 될 차세대 친환경 에너지로써 태양광 에너지가 각광 받고 있다. 이에 본 연구에서는 국내 공단에 Test-Bed를 선정하여 수용가의 대응용 태양광 ESS 시스템 적용함에 있어 Peak-cut 운영을 위한 Charge Operation Plan과 Discharge Operation Plan 운영방안을 최대수요전력 감소 시뮬레이션을 통해 검증하고자 한다. 이를 위해 전력사용량이 가장 많은 11월부터 2월의 전력사용량을 선정하여 Charge/Discharge Logic을 적용했다. 본 논문에서 제시한 충전/방전 로직에 따른 시뮬레이션 결과, ESS Peak-cut 서비스 이후의 최대수요전력이 감소하였으며 Peak-target 전력의 50%로 감소함에 따라 계약전력 또한 감소함을 알 수 있다. 이를 통해 계약전력 감소는 해당 수용가의 기본 전력 값을 감소시켜, 경제적 우월성을 기대할 수 있을 뿐만 아니라 전기품질 향상 및 전력공급시스템의 안정화에도 기여할 수 있을 것으로 판단된다.

• JSTS:Journal of Semiconductor Technology and Science
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• 제10권3호
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• pp.165-175
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• 2010

This paper presents a fine-grain supply-voltage-control scheme for low-power FPGAs. The proposed supply-voltage-control scheme detects the critical path in real time with small overheads by exploiting features of asynchronous architectures. In an FPGA based on the proposed supply-voltage-control scheme, logic blocks on the sub-critical path are autonomously switched to a lower supply voltage to reduce the power consumption without system performance degradation. Moreover, in order to reduce the overheads of level shifters used at the power domain interface, a look-up-table without level shifters is employed. Because of the small overheads of the proposed supply-voltage-control scheme and the power domain interface, the granularity size of the power domain in the proposed FPGA is as fine as a single four-input logic block. The proposed FPGA is fabricated using the e-Shuttle 65 nm CMOS process. Correct operation of the proposed FPGA on the test chip is confirmed.