• International Journal of Naval Architecture and Ocean Engineering
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• 제7권2호
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• pp.324-345
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• 2015

A new procedure for determining properties of thick plate finite elements, based on the modified Mindlin theory for moderately thick plate, is presented. Bending deflection is used as a potential function for the definition of total (bending and shear) deflection and angles of cross-section rotations. As a result of the introduced interdependence among displacements, the shear locking problem, present and solved in known finite element formulations, is avoided. Natural vibration analysis of rectangular plate, utilizing the proposed four-node quadrilateral finite element, shows higher accuracy than the sophisticated finite elements incorporated in some commercial software. In addition, the relation between thick and thin finite element properties is established, and compared with those in relevant literature.

• 한국추진공학회지
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• 제14권2호
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• pp.54-62
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• 2010

본 논문에서는 고속 비행체의 공기유동 데이터 측정 시스템에 직접 적용이 가능하며 고 신뢰도를 갖는 유동 데이터 처리 알고리즘 개발에 대해 기술하였다. 과거 공기유동 데이터 획득시스템과는 다르게 전산유동해석(CFD)을 통해 미리 획득한 데이터를 적용한 알고리즘으로 전압력 측정이 필요 없이 충분 한 센서 여유(redundancy) 및 오류 검출기능을 지니고 있다. 개발된 알고리즘에 대한 검증은 상용 프로그램인 매트랩 및 시뮬링크를 사용하여 진행하였다.

• 한국태양에너지학회 논문집
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• 제38권4호
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• pp.11-31
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• 2018

Nowadays, domestic photovoltaic system market has been expanded and the governmental dissemination policy has been continued. There is only PV system output performance analysis which is called Performance Ratio(PR) analysis. However, there exists many parameters that can affect PV system output. This papers shows the PV system energy performance analysis using meteorological monitoring data. The meteorological monitoring system was installed in the H university and we analyzed the PV system which installed in the H university. We also investigated other three PV systems which located less than 3 kilometers from H university. We evaluated total 4 PV systems through the field survey data, design drawing data and power generation data. Finally, we compared the actual measuring data with the simulation data using PVSYST software.

• 반도체디스플레이기술학회지
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• 제19권2호
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• pp.1-10
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• 2020

Blockchain enabled Decentralized Autonomous Organization (DAO), a new form of organization with conveying its core value - trust. Token holders who are participating DAO's governance share their thoughts, information, and ideas in online forum. But it is problem that chronological form of DAO's online forum makes token holders hard to find crucial information, meaning that many of them might not understand what is happening discussion. In this paper, we studied not only a decision making process which feature is iteration, visualization, and applicable to DAO with 6 steps in total but also a decision making tool which is based on the process of this paper. The tool has features to help participants such as voting model, visualization features which gives guidance to them for their decision during the process. Our experiment showed that the process and tool is somewhat reasonable, and the information during the process is effective for participants. This work is expected to be applied to current DAOs to make a decision among the token holders.

• Journal of Information Technology Applications and Management
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• 제13권2호
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• pp.17-28
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• 2006

The SRGM has been studied under the assumption that S/W reliability can grow as the fault causing failure is removed even during operational phase because the debugging is available. On the other hand, some papers insist on the uniform failure rate during operational phase because the debugging may not be available in case of universal software. The phenomenon, however, has been observed informally many times that the products S/W reliability grows as the time goes by even without any debugging in point of customer view. I propose the simple approaching method to model the S/W reliability phenomenon that the failure rate reduces as time goes on without modifying the existing reliability model in this paper.

• 한국정보통신학회논문지
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• 제1권2호
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• pp.183-191
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• 1997

동시 다발적으로 공격해 오는 위협 표적을 방어하기는 매우 어려우며, 특히 방어용 무장수보다 표적의 수가 많을 경우에는 전체 표적 격추 기대 확률이 최대가 될 수 있도록 유지하는 방법으로서 본 논문에서는 홉필드 신경망 기법을 무장 할당 알고리즘으로 이용하는 방안을 제안하였다. 본 연구는 자동무장할당 알고리즘을 설계함에 있어서 할당변수를 생성하는데 필요한 신경망 학습 횟수를 단축하도록 설계하였으며 컴퓨터 시뮬레이션 결과 watcholder의 방법보다 수렴성이 뛰어남을 확인하였다.

• Journal of Power Electronics
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• 제6권2호
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• pp.146-162
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• 2006

This paper deals with the analysis, design and implementation of an AC-DC Zeta converter in discontinuous current mode (DCM) of operation used for power quality improvement at AC mains in direct torque controlled (DTC) permanent magnet synchronous motor (PMSM) drives. The designed Zeta converter feeds a direct torque controlled PMSM drive system. Modeling and simulation is carried out in a standard PSIM software environment. Test results are obtained on the developed prototype Zeta converter using DSP ADMC401. The results obtained demonstrate the effectiveness of the Zeta converter in improving power quality at AC mains in the PMSM drive system.

• 조명전기설비학회논문지
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• 제27권3호
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• pp.87-94
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• 2013

The main purpose of the distribution automation system (DAS) is to achieve efficient operation of primary distribution systems by monitoring and control of the feeder remote terminal unit(FRTU) deployed on the distribution feeders. DAS simulators are introduced to verify the functions of the application software installed in the central control unit(CCU) of the DAS. Because each DAS is developed on the basis of its own specific data model, the power system data cannot be easily transferred from the DAS to the simulator or vice versa. This paper presents a common information model(CIM)-based DAS simulator to achieve interoperability between the simulator and the DASs developed by different vendors. The CIM-based data model conversion between Smart DMS (SDMS) and Total DAS (TDAS) has been performed to establish feasibility of the proposed scheme.

• Journal of Power Electronics
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• 제10권4호
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• pp.374-381
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• 2010

Typical power electronic converters employ only pulse width modulation (PWM) to generate specific switching patterns. In this paper, a novel control strategy combining both pulse-width and amplitude modulation strategies (PWAM) has been proposed for power converters. The Pulse Amplitude Modulation (PAM), used in communication systems, has been applied to power electronic converters. This increases the degrees of freedom in eliminating or mitigating harmonics when compared to the conventional PWM strategies. The role of PAM in the novel PWAM strategy is based on the control of the converter's dc sources values. Software implementation of the conventional PWM and the PWAM control strategies has been applied to a five-level inverter for mitigating selective harmonics. Results show the superiority of the proposed strategy from the THD point of view along with a reduction in the inverter power dissipation.

• Journal of Information Processing Systems
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• 제1권1호
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• pp.27-31
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• 2005

Vehicle detector system based on image processing technology is a significant domain of ITS (Intelligent Transportation System) applications due to its advantages such as low installation cost and it does not obstruct traffic during the installation of vehicle detection systems on the road[1]. In this paper, we propose architecture for vehicle detection by using image processing. The architecture consists of two main parts such as an image processing part, using high speed FPGA, decision and calculation part using CPU. The CPU part takes care of total system control and synthetic decision of vehicle detection. The FPGA part assumes charge of input and output image using video encoder and decoder, image classification and image memory control.