• 정보관리연구
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• 제32권3_4호
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• pp.31-42
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• 2001

전문도서관이 당면한 문제는 변화하는 출판 및 도서관 환경 속에서 제한된 자원으로 이용자의 다양한 요구를 만족시키기가 더욱 어려워지고 있다는 점이다. 최근 인터넷과 정보기술의 발달 그리고 전자자원의 증가는 자료의 확인과 전달 시스템의 향상 등 공동수서의 기술적인 기반을 제공해 주었다. 본 논문은 전문도서관 공동수서의 배경과 방법을 CRL, OhioLINK, RLG Conspectus, TRLN 등의 사례들을 중심으로 살펴보고, 효과적인 공동수서를 위한 과제와 전략을 제시하였다.

• Journal of Electrical Engineering and Technology
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• 제6권5호
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• pp.723-730
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• 2011

The GPS modernization program offered a new civil signal on the L2 band, and the first modernized GPS Block IIR satellite was launched in September 2005. Currently, eight GPS Block IIRM satellites and two Block IIF satellites transmit L2C signal. The L2C signal contains two codes of CM and CL that are much longer than the L1 C/A code. Thus, the acquisition of the CM and CL codes takes more time compared with that of L1 C/A code. Under the assumption that the L2C signal is strong enough for detection, this paper suggests rapid acquisition methods for the GPS L2C signals for software receivers and compares its performance with that of other methods.

• 한국통신학회논문지
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• 제33권12C호
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• pp.983-990
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• 2008

통신 시스템에서 초기 동기 획득은 안정적인 송수신 성능을 위해 필수적이며, 특히 신호 대 잡음 비의 변화를 포함하는 다양한 통신 환경에서 동기 획득 성능의 분석은 시스템 설계를 위해 중요한 역할을 한다. 주파수 오차가 존재하는 경우 초기 동기에서 차등 상관 방식의 활용이 바람직하며, 기존 상관 방식의 적절한 변형을 통해 추가적인 성능 향상이 가능하다. 본 논문에서는 차등 상관기 출력 값의 분포를 확률적으로 모델링함으로써 초기 동기 시의 오율을 Marcum Q-function의 형태로 유도하며, 출력 값의 복소 합 또는 크기 합을 이용하는 확장된 차등 상관 방식의 초기 동기 획득 시의 오율 결정으로 일반화한다. 제시된 결과는 DVB-S2 (Digital Video Broadcasting - via Satellite, Second Generation) 표준을 포함하는 다양한 통신 시스템의 동기 성능 검증을 위해 활용될 수 있다.

• 한국경영과학회:학술대회논문집
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• 한국경영과학회 2004년도 추계학술대회 및 정기총회
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• pp.173-176
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• 2004

Understanding the fact that more spending for R&D is merely a necessity, not a factor of success, managing technological development efforts effectively and efficiently for higher R&D productivity and sustainable growth has become an important issue for contemporary firms. Based on a survey on small- and medium-sized manufacturing firms, this paper explores the relationships of leadership positions, technological contents and acquisition methods of korean firms. This paper has identified several findings from Korean manufacturing firms: (1) five different patterns are identified in the technology strategy of medium-sized companies; (2) a significantly positive relationship exists between a firm's leadership position and the aggressiveness in technological contents of their acquisition methods; (3) a significantly positive relationship of some technology acquisition methods to the firms' leadership position exists,

• 지능정보연구
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• 제1권1호
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• pp.91-109
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• 1995

This paper compared four knowledge acquisition methods (namely, neural network, case-based reasoning, discriminant analysis, and covariance structure modeling) for allergic rhinitis. The data were collected from 444 patients with suspected allergic rhinitis who visited the Otorlaryngology Deduring 1991-1993. Among four knowledge acquisition methods, the discriminant model had the best overall diagnostic capability (78%) and the neural network had slightly lower rate(76%). This may be explained by the fact that neural network is essentially non-linear discriminant model. The discriminant model was also most accurate in predicting allergic rhinitis (88%). On the other hand, the CSM had the lowest overall accuracy rate (44%) perhaps due to smaller input data set. However, it was most accuate in predicting non-allergic rhinitis (82%).

• 한국건설관리학회:학술대회논문집
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• 한국건설관리학회 2004년도 제5회 정기학술발표대회 논문집
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• pp.188-193
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• 2004

3차원 모델링은 다양한 safety-enhancement applications 과 프로젝트 관리 시스템에서의 as-built data acquisition에 이용될 수 있다. 본 연구의 목적은 효과적인 방법으로 건설 현장을 3차원 모델로 형상화 할 수 있는 3차원 공간 모델링 방법을 제시하고 실제 건설 현장에서의 실험을 통하여 제시한 방법을 검증하는 것이다. 본 논문에서는 제안된 건설현장을 형상화하기 위한 모델링 알고리듬들과 여러 장소들로부터 얻는 data를 하나의 coordinate system으로 변환하기 위한 coordinate transformation 알고리듬에 대한 설명을 포함하였다. 제안된 모델링 방법의 건설 현장에 대한 실제 적용성을 검증하기 위해 실제 건설 현장에서의 모델링 실험에 대한 결과가 논의되었으며 이러한 결과는 본 연구에서 제안된 모델링 방법이 건설 현장을 효과적으로 3차원 모델로 형상화하는 것을 보여준다.

• International Journal of Advanced Culture Technology
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• 제7권2호
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• pp.179-187
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• 2019

As the globalization process progresses more rapidly and widely, there has been a ever-growing demand for multilingual learning. Compared with the study of Second Language Acquisition, studies on the Third Language and even Multilingual Acquisition have attracted a relatively poor attention. At the same time, considering current educational environments for ethnic colleges and universities, the effects of college English teaching for minority students can be said to have been 'generally poor.' In this situation, when we try to find ways to improve college English studies for minority students most of whom already can speak two languages or even more, it would not be the best idea to keep following the experiences of traditional Second Language Acquisition. It is necessary first to find out whether there are positive or negative effects in acquiring multiple languages, and then to conduct a profound research on L3 (third language and even multilingual) Acquisition in order to employ more efficient teaching methods for multilingual learners. After conducting a Japanese-teaching experiment on two groups of learners with mono-lingual and bilingual backgrounds, it has been found that there is a positive transfer between different languages. In this paper, following the recent research findings on Language teaching for multilingual learners, I try to show with further supports that when it comes to language education for learners with multilingual backgrounds, we should focus on the advantages they may earn in order to conduct more effective language acquisition.

• 전기전자학회논문지
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• 제24권2호
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• pp.649-653
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• 2020

대표적인 위성 항법 시스템인 GPS는 사용자에게 위치와 시간을 제공한다. GPS L1 C/A는 민간용으로 개발되어 다양한 분야에서의 높은 활용도를 보인다. 위성 신호가 수신기에 도달하면 디지털 신호 처리단의 신호 획득부에서 가시 위성의 신호를 검색 후 획득하고, 획득한 신호는 신호 추적단에서 실시간으로 신호를 추적하며 항법 메시지를 추출한다. 신호 획득부는 직렬 검색 획득, 병렬 주파수 검색 획득, 병렬 코드 위상 검색 획득 등 신호 검색 방식에 따라 구현 방식이 달라지는데, 본 논문에서는 세 가지 검색 방식에 따라 GPS L1 C/A코드용 신호 획득부를 구현하고 각각을 비교한다. 직렬 검색 획득과 병렬 주파수 검색 획득에 비해서 병렬 코드 위상 검색 획득은 검색 횟수를 줄일 수 있고 높은 해상도의 상관값을 가질 수 있기 때문에 계산과정 중 필요한 연산의 복잡도를 줄인다면 항법 시스템의 빠른 동작을 위해서 최적의 검색 방식으로 사용될 수 있다.

• 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.

• 한국지능시스템학회논문지
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• 제8권6호
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• pp.70-77
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• 1998

Although many methods of knowledge acquisition has been developed in the exper systems field, such a need form causal knowledge acquisition hs not been stressed relatively. In this respect, this paper is aimed at suggesting a causal knowledge acquisition process, and then investigate the causal knowledge-based inference process. A vehicle for causal knowledge acquisition is FCM (Fuzzy Cognitive Map), a fuzzy signed digraph with causal relationships between concept variables found in a specific application domain. Although FCM has a plenty of generic properties for causal knowledge acquisition, it needs some theoretical improvement for acquiring a more refined causal knowledge. In this sense, we refine fuzzy implications of FCM by proposing fuzzy causal relationship and fuzzy partially causal relationship. To test the validity of our proposed approach, we prototyped a causal knowledge-driven inference engine named CAKES and then experimented with some illustrative examples.