• Journal of Power Electronics
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• 제12권5호
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• pp.813-820
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• 2012

This paper presents the development of a software supported acquisition system for metrological verification and testing of the equipment for monitoring and analysis of the basic electrical power quality parameters. The described procedure consists of two functionally connected segments. The first segment involves generation of the reference three-phase voltage signals, including the possibility of simulation of the various power quality disturbances, typical for electrical power distribution networks. The second part of this procedure includes the real-time recording of power quality disturbances in three-phase distribution networks. The procedure is functionally supported by the virtual instrumentation concept, including a software application developed in LabVIEW environment and data acquisition boards NI 6713 and NI 9215A. The software support of this system performs graphical presentation of the previously generated and recorded signal waveforms. A number of the control functions and buttons, implemented on the virtual instrument front panels, are provided to adjust the basic signal acquisition, generation and recording parameters.

• 한국융합학회논문지
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• 제10권3호
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• pp.31-37
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• 2019

본 논문에서는 현재 육군에서 추진하고 있는 드론봇 전투체계에서 부대단위별 효율적 감시정찰 임무를 수행하기 위한 드론의 편제소요를 도출할 수 있는 방법을 제안한다. 본 논문에서는 육군의 대대 및 중대의 감시정찰 임무와 관련된 정면과 종심, 중요감시지역 수의 문제를 실제 작전환경을 고려하여 가정하였으며 first, next, valid, output 4단계의 Brute Force 알고리즘을 적용한 시뮬레이션을 통하여 대대 및 중대의 감시정찰에 필요한 최소한의 드론 대수를 도출하였고 각각 드론의 경로계획을 수립하였다. 그 결과, 육군의 드론봇 전투체계에서는 본 논문에서 제안한 방법을 적용하여 부대별 임무에 특성에 따라 보다 간단하고 빠르게 임무수행에 필요한 드론의 편제소요를 도출할 수 있을 것이다. 향후에는 본 논문에서 제안한 방법을 이용한 편제소요 도출방안의 신뢰성 검증에 대한 연구를 진행하도록 하겠다.

• 한국추진공학회:학술대회논문집
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• 한국추진공학회 2008년 영문 학술대회
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• pp.16-21
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• 2008

Aero-engine, as one kind of rotating machinery with complex structure and high rotating speed, has complicated vibration faults. Therefore, condition monitoring and fault diagnosis system is very important for airplane security. In this paper, a vibration data acquisition and intelligent fault diagnosis system is introduced. First, the vibration data acquisition part is described in detail. This part consists of hardware acquisition modules and software analysis modules which can realize real-time data acquisition and analysis, off-line data analysis, trend analysis, fault simulation and graphical result display. The acquisition vibration data are prepared for the following intelligent fault diagnosis. Secondly, two advanced artificial intelligent(AI) methods, mapping-based and rule-based, are discussed. One is artificial neural network(ANN) which is an ideal tool for aero-engine fault diagnosis and has strong ability to learn complex nonlinear functions. The other is data mining, another AI method, has advantages of discovering knowledge from massive data and automatically extracting diagnostic rules. Thirdly, lots of historical data are used for training the ANN and extracting rules by data mining. Then, real-time data are input into the trained ANN for mapping-based fault diagnosis. At the same time, extracted rules are revised by expert experience and used for rule-based fault diagnosis. From the results of the experiments, the conclusion is obvious that both the two AI methods are effective on aero-engine vibration fault diagnosis, while each of them has its individual quality. The whole system can be developed in local vibration monitoring and real-time fault diagnosis for aero-engine.

• 시스템엔지니어링학술지
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• 제8권1호
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• pp.77-82
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• 2012

In Weapons acquisition process, if the requirements are not clear, it leads to confusion and conflict in business. In the development of next-generation weapons, to define and derive requirements has to start from decision of operational concept. It is difficult task and has many uncertainties. This paper has goal about development of knowledge acquisition process that derive military operational scenario-based requirements acquisition process and framework that classify and save the derived requirements for next project. That framework can generate new class and category, also suggest that verification of requirements. It help to derive and manage the requirements, and make it easy to grasp the requirements. Accordingly, it can help make military requirement plan and weapon acquisition process.

• 한국도서관정보학회지
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• 제14권
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• pp.217-240
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• 1987

The purpose of this study is to analyse the current theses acquisition in university libraries and to suggest some useful findings for the more efficient acquisition of the theses. The results of the study can be summarized as follows (1) Depositary copies of each thesis in the libraries should be increased. (2) Under cooperative efforts, libraries must establish the exchange system of the theses by region or subject or characteristics of universities. (3) Each library should set up concrete selection criteria for the receiving of theses. (4) Development of purchase system would be necessary for economic and prompt acquisition of theses. (5) Theses should be microformed so as to save their storage space. (6) To give su n.0, pport to effective acquisition activity, various bibliographies about theses should be published.

• 전자공학회논문지A
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• 제33A권5호
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• pp.24-30
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• 1996

In this paper, we propose a fast code acquisition method that can reduce drastically the mean acquisition time of the direct sequence spread spectrum (DS-SS) system by using and integrated search and verification (ISV) scheme. The proposed method performs simultaneously the search and verification processes at every search cell, through storing sufficiently long signal samples enough to perform the verification process form the previously received samples. We analyze and acquisition performance in the case of Gaussian channel to evaluate theacquisition perfomrance of the proposed method. From the simple numericl analysis result, we have shown that the acquisition performance of the proposed method is better than that of the conventional serial search method, and the performance improvement becomes more prominent as the channel environment becomes degraded.

• Korean Journal of Geomatics
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• 제1권1호
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• pp.85-93
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• 2001

Geospatial database, which is the basis for Geo-Spatial Information Systems, is produced by conventional mapping methods. Recently, with increased demand for digital forms of the geospatial database, studies are carried out to automate its production. The automated mapping system is composed of the image acquisition subsystem, positioning subsystem, point referencing subsystem and the visualization subsystem. The image acquisition subsystem is the most important part of the overall production line because it is the starting point and will affect all subsequent processes. This paper presents a software analysis and design of the image acquisition subsystem. The design was carried out using the Unified Modeling Language which is a modeling method used extensively in the software engineering field.

• 전자공학회논문지S
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• 제34S권8호
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• pp.10-19
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• 1997

In this paper, perfodrmance of matched-filter (MF) acquisition scheme is analyzed for a direct-sequence/code-division-multiple-access (DS/CDMA) system in a microcellular environment. Mean acquistion time is used as a performance measure. It is demonstrated that acquisition performance is enhanced using interference suppression filter in a Rician fading channel. To apply for multiuser environments, multiple access interference is considered in the performance analysis. From the numerical results, it is shown that mean acquistion time decreases with the increasing SNR/chip, and acquisition performance is improved as the number of taps of interference suppression filter. It is also shown that mean acquisition time increases with the number of users in the system, and acquistion performance is degraded as the icrease of narrowband interference bandwidth. The analysis in this paper can be applied to a DS/CDMA overlay environment.

• 한국해양공학회:학술대회논문집
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• 한국해양공학회 2001년도 춘계학술대회 논문집
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• pp.166-171
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• 2001

A digital seismic data acquisition and processing system using a PC has been developed in order to replace the analog data acquisition system of shallow marine seismic survey. An A/D converter that has 12bits of resolution and 225KHz of conversion rate was ued to acquire data, and a data acquisition software was developed as a Windows program which provides convenience of use. Raw data acquired at field has been saved to the hard-disk simultaneously. The signal to noise ratio, vertical and horizontal resolution could be improved by a digital data processing of the raw data. The digital processing of the raw data includss gain recovery, filtering, deconvolution, and muting. With the prediction deconvolution algorithm multiple reflections appearing on the shallow marine seismic section could be removed successfully.

• 한국컴퓨터정보학회논문지
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• 제7권3호
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• pp.128-134
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• 2002

본 논문에서는 나카가미-m 확률밀도함수를 이용하여 페이딩 환경을 고려한 DS/CDMA시스템의 PN 부호 획득(acquisition)에 대한 성능을 분석하였다. 성능 분석은 PN 부호 획득 시간에 영향을 미치는 검출확률(detection Probability) $P_D$와 오경보확률(false alarm probability) $P_{FA}$에 대한 식을 유도하여 시뮬레이션으로 입증하였다. 그 결과 위상 에러를 보정하기 위하여 PLL의 이득을 높이고 레이크 수신기를 동시에 적용할 경우 PN 부호의 검출확률 $P_D$는 개선되었고, 오경보확률 $P_{FA}$는 감소하여 PN 부호의 동기 획득 성능을 개선시킬 수 있음을 입증하였다.