• 정보처리학회논문지:소프트웨어 및 데이터공학
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• 제3권6호
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• pp.237-242
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• 2014

기존 사용되고 있는 디지털 도어락 시스템은 사용자의 편의에 중점을 두어 보안 측면에서는 취약한 단점이 있다. 이에 본 논문은 중계기, 서버, 카메라와 센서, 통신 모듈이 결합된 디지털 도어락 시스템화하여 도어락 설치장소 전방에서 접근하는 객체를 감지 및 인식하고 이미지와 문 열림 정보를 사용자의 스마트 디바이스로 전송해 주는 영상 디지털 도어락 시스템을 제안하고자 한다. 제안한 시스템은 실험결과 대상거리 내에서 96~98%의 접근자 인식률과 사용 통신망에 따라 평균 약 17.1~23.9초의 전송시간이 소요되었다. 따라서 도어락 시스템 전방의 상황을 모니터링하여 실시간 보안 대응이 가능할 것으로 판단된다.

• 한국비블리아학회지
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• 제23권3호
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• pp.139-155
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• 2012

급속한 정보환경의 변화는 여러 산업에 걸쳐 비즈니스 패러다임을 급격하게 바꾸고 있으며 전 세계적으로 그 확산 속도는 기하급수적으로 증가하고 있다. 이에 도서관에서도 예측 불가능한 변화에 대처하기 위해서 신속하게 반응할 수 있는 능력인 민첩성 역량을 이용하여 정보서비스를 제공해야할 필요가 있다. 특히 원활한 연구 및 교육 활동을 돕기 위해 최신 정보와 방대한 범위의 정보 제공을 하고 있는 대학 디지털도서관에서의 민첩성 역량은 더욱 중요한 요인으로 판단된다. 따라서 본 연구는 민첩성 역량에 대해서 살펴본 뒤 대학 디지털도서관 e-서비스 측정 평가 요인과 민첩성 요인들과의 관계에 대해 알아보고, 또한 민첩성 역량이 이용자의 만족도에 미치는 영향에 대해 분석하였다. 이를 바탕으로 대학 디지털도서관 운영 및 경영에 있어 고려해야할 사안들을 제안하였다.

• 한국조명전기설비학회지:조명전기설비
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• 제11권1호
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• pp.114-122
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• 1997

본 연구에서는 계량 설비에 사용되는 스마트형 디지털 로드셀을 개발하였다. 로드셀 센서는 중량의 변화에 대해 매우 민감하여햐 하므로 정밀한 A/D변환을 위하여 온도 안정성, 낮은 드리프트 특성 그리고 분해능이 우수하여야 한다. 단일칩 마이크로프로세서에 의해 제어되는 고안된 아날로그 회로로써 OP엠프 오프셋과 드리프트 특성을 저감시키며 소프트웨어 알고리즘에 의해 안정되고 정밀한 A/D 변환이 가능하도록 디지털 로드셀을 설계하였다. 또한 RS-485통신 방식으로 로드셀을 제어하고 보정용 데이터와 제어 데이터를 기억시키는 기능들도 포함하였다. 시뮬레이션과 실측 평가를 통하여 개발된 로드셀의 우수성을 입증하였으며, 본 연구의 결과는 원격계량 센서로서 계량 설비 분야에 유용한 활용이 기대된다.

• Earthquakes and Structures
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• 제22권5호
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• pp.503-515
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• 2022

This paper presents the development of seismic fragility curves for a precast reinforced concrete bridge instrumented with a structural health monitoring (SHM) system. The bridge is located near an active seismic fault in the Dominican Republic (DR) and provides the only access to several local communities in the aftermath of a potential damaging earthquake; moreover, the sample bridge was designed with outdated building codes and uses structural detailing not adequate for structures in seismic regions. The bridge was instrumented with an SHM system to extract information about its state of structural integrity and estimate its seismic performance. The data obtained from the SHM system is integrated with structural models to develop a set of fragility curves to be used as a quantitative measure of the expected damage; the fragility curves provide an estimate of the probability that the structure will exceed different damage limit states as a function of an earthquake intensity measure. To obtain the fragility curves a digital twin of the bridge is developed combining a computational finite element model and the information extracted from the SHM system. The digital twin is used as a response prediction tool that minimizes modeling uncertainty, significantly improving the predicting capability of the model and the accuracy of the fragility curves. The digital twin was used to perform a nonlinear incremental dynamic analysis (IDA) with selected ground motions that are consistent with the seismic fault and site characteristics. The fragility curves show that for the maximum expected acceleration (with a 2% probability of exceedance in 50 years) the structure has a 62% probability of undergoing extensive damage. This is the first study presenting fragility curves for civil infrastructure in the DR and the proposed methodology can be extended to other structures to support disaster mitigation and post-disaster decision-making strategies.

• 한국정보통신학회:학술대회논문집
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• 한국해양정보통신학회 1999년도 춘계종합학술대회
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• pp.425-431
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• 1999

본 연구에서는 플라즈마 감시에 의한 용접성 평가방식을 채택한다. 플라즈마에서 발생하는 자외선신호를 반도체 광센서를 사용하여 검출하고, 감시장치로 쓰이는 개인용 컴퓨터에 고속으로 전달, 저장하는 장치를 개발한다. 이 장치를 사용하여 용접 데이터베이스를 구축하고, 용접성과 플라즈마 신호와의 관계를 평가하고, 분석할 것이다. 이 분야에 대한 연구동향을 하면 표2와 같다. 그러나 이 연구들은 모두 사용한 장치의 특성, 플라즈마발생원에 대한 센서의 상대적 위치 및 자세와 획득 신호와의 관계, 용접할 때 발생하는 열의 센서에 대한 영향, 잡음이 취득된 신호에 미치는 영향 및 회피방법 둥에 대한 언급이 없다. 따라서 논문에 실린 신호의 파형은 대부분 일관성이 없으며, 참고가 어렵다. 본 연구에서는 이러한 관계를 도출하고, 특히 잡음의 영향을 최소화하는 장치화에 주안점을 둔다.

• Journal of Electrical Engineering and Technology
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• 제11권3호
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• pp.618-628
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• 2016

Active power filter (APF) has been proved as a flexible solution for compensating the harmonic distortion caused by nonlinear loads in power distribution power systems. Digital repetitive control can achieve zero steady-state error tracking of any periodic signal while the sampling points within one repetitive cycle must be a known integer. However, the compensation performance of the APF would be degradation when the grid frequency varies. In this paper, an improved repetitive control scheme with frequency adaptive capability is presented to track any periodic signal with variable grid frequency, where the variable delay items caused by time-varying grid frequency are approximated with Pade approximants. Additionally, the stability criterion of proposed repetitive control scheme is given. A three-phase shunt APF experimental platform with proposed repetitive control scheme is built in our laboratory. Simulation and experimental results demonstrate the effectiveness of the proposed repetitive control scheme.

• 한국해양공학회지
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• 제24권3호
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• pp.64-71
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• 2010

This paper summarizes the development of an ART control system panel with a touch screen and sensors to measure the roll and roll rate of ships. The control system hardware consists of two micro-processors, analog and digital I/O circuits, various relay circuits, etc. Sensor fusion and moving cross algorithms are implemented to accurately estimate the roll angle and roll period. In addition, the control system adopts a fault detection algorithm to inform users of ART system faults. A touch screen in the control panel can display the ART system states and faults. The performance of the developed system was verified on real sea trials.

• 전력전자학회:학술대회논문집
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• 전력전자학회 2013년도 전력전자학술대회 논문집
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• pp.126-127
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• 2013

In industry, Supervisory Control and Data Acquisition (SCADA) system plays critical role to ensure production is monitored and controlled rigorously and in timely manner. Having a cost saving yet still effective SCADA system would be much desired by Industry. SCADA itself is a field with constant development and research like how this paper investigates on creating an extremely low cost device, which can be adapted to many different SCADA applications through some very basic programming when combined with relevant peripherals. Much of the process in some expensive SCADA application based on smartphone application is due to specialized communication infrastructure. This paper addresses the needs by developing low cost and integrated wireless SCADA system. The system features capability on accessing the performance of remotely situated device parameter, such as temperature, control analog or digital input output on real time basis. We use existing mobile network capability through Bluetooth communication channel.

• 전자공학회논문지B
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• 제32B권11호
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• pp.1527-1535
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• 1995

This paper introduces an isolated word recognition system realized on a neurocomputer called E-MIND II, which is a 2-D torus wavefront array processor consisting of 256 DNP IIs. The DNP II is an all digital VLSI unit processor for the EMIND II featuring the emulation capability of more than thousands of neurons, the 40 MHz clock speed, and the on-chip learning. Built by these PEs in 2-D toroidal mesh architecture, the E- MIND II can be accelerated over 2 Gcps computation speed. In this light, the advantages of the E-MIND II in its capability of computing speed, scalability, computer interface, and learning are especially suitable for real time application such as speech recognition. We show how to map a TDNN structure on this array and how to code the learning and recognition algorithms for a user independent isolated word recognition. Through hardware simulation, we show that recognition rate of this system is about 97% for 30 command words for a robot control.

• 농촌지도와개발
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• 제7권2호
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• pp.279-288
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• 2000

Agricultural extension services in Korea are faced with increasing demands for more efficient production and managerial technology according to globalization and free trade system. At the same time, three steps of organizational restructuring in 1998 and 1999 resulted in decreased number of organization and manpower, thus, resulting confusion in implementing extension services. To cope with the international and national challenges, Korean agricultural extension services should try paradigm shift including the followings; 1. To establish identity of agricultural extension services in Korea through making laws and regulations in terms of concept, roles, principles. implementation and methods. 2. To implement vitalizations plan through enhancement of national extension service such as food production. raising local specialty products for domestic consumption and producing strategic agricultural products for export. expanding capability of rural women, increasing opportunity for management consultation, supporting digital technology information, and promoting morale and capability of extension educators. 3. To reform agricultural extension system through adjusting the functions of extension service of the Rural Development Administration, regionalizing city and county extension center to provincial level, and changing the status of directors of extension centers from city /county to national government.