• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.1161-1164
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• 1996

In this paper, a parameter optimization technique for a mobile robot navigation is discussed. Authors already have proposed a navigation algorithm for mobile robots with sonar sensors using fuzzy decision making theory. Fuzzy decision making selects the optimal via-point utilizing membership values of each via-point candidate for fuzzy navigation goals. However, to make a robot successfully navigate through an unknown and cluttered environment, one needs to adjust parameters of membership function, thus changing shape of MF, for each fuzzy goal. Furthermore, the change in robot configuration, like change in sensor arrangement or sensing range, invokes another adjusting of MFs. To accomplish an intelligent way to adjust these parameters, we adopted a genetic algorithm, which does not require any formulation of the problem, thus more appropriate for robot navigation. Genetic algorithm generates the fittest parameter set through crossover and mutation operation of its string representation. The fitness of a parameter set is assigned after a simulation run according to its time of travel, accumulated heading angle change and collision. A series of simulations for several different environments is carried out to verify the proposed method. The results show the optimal parameters can be acquired with this method.

• 한국지능시스템학회논문지
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• 제15권6호
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• pp.682-687
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• 2005

본 논문에서는 생물의 2차원영상에서 5가지 특징을 추출한 다음 약품에 대한 생물의 행동 패턴 반응에 대하여 의사결정나무를 적용하여 패턴의 인식 및 분류를 하였다. 생물의 행동패턴을 대변하는 물리적인 특징인, 속도, 방향전환 각도, 이동거리에 대하여 각각 중간이상속도비율 FFT(Fast Fourier Transform), 2차원 정사영 면적, 프렉탈 차원, 무게중심을 사용하여 특징을 추출하였다. 이렇게 추출된 5가지의 특징변수들을 사용하여 의사결정나무 모델을 구성한 다음 생물의 약품 첨가에 대한 반응을 분석하였다 또한 결과에서는 기존의 생물의 행동패턴 구분에 쓰였던 전형적인 기법(conventional methods) 보다 본 연구에서 적용한 의사결정나무가 생물의 행동패턴이 가지는 물리적 요소에 대한 독해력을 가짐을 보임으로써 특정 환경에서 이동행동에 대한 분석을 용이하게 하고자 하였다.

• 한국통신학회논문지
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• 제31권2C호
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• pp.117-122
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• 2006

본 논문에서는 로그 최우비(log likelihood ratio, LLR)를 이용하여 Gray 부호화된 PAM신호를 위한 비트 연판정 계산식을 제안한다. 이 계산식은 Gray 매핑 특성을 이용하여 Max-Log-MAP 알고리듬에서 필요한 max0/min0 함수를 사용하지 않고 산술 연산만을 사용하기 때문에 구현이 간단하다. 제안된 식의 결과는 기존 Max-Log-MAP 알고리듬의 결과와 일치한다. 또한, 식에 사용되는 인자들은 송수신 시스템이 서로 공유하는 정보와 수신된 심벌 값만을 이용하여 계산한다. 따라서 본 논문에서 제안된 알고리듬은 일반적으로 많이 사용하는 이진 반복 복호기 등과 함께 실제 응용 설계에 적용이 가능하며, 특히 실제 설계에 적용되는 기존의 여러 가지 알고리듬에 비하여 구조가 유연하고 효율적이며 정확한 비트별 LLR을 제공하는 효율적인 방법 중의 하나이다.

• International Journal of Fuzzy Logic and Intelligent Systems
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• 제7권1호
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• pp.58-65
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• 2007

Behavioral sequences of the medaka (Oryzias latipes) were continuously investigated through an automatic image recognition system in response to medaka treated with the insecticide and medaka not treated with the insecticide, diazinon (0.1 mg/l) during a 1 hour period. The observation of behavior through the movement tracking program showed many patterns of the medaka. After much observation, behavioral patterns were divided into four basic patterns: active-smooth, active-shaking, inactive-smooth, and inactive-shaking. The "smooth" and "shaking" patterns were shown as normal movement behavior. However, the "shaking" pattern was more frequently observed than the "smooth" pattern in medaka specimens that were treated with insecticide. Each pattern was classified using classification methods after the feature choice. It provides a natural way to incorporate prior knowledge from human experts in fish behavior and contains the information in a logical expression tree. The main focus of this study was. to determine whether the decision tree could be useful for interpreting and classifying behavior patterns of the medaka.

• Management Science and Financial Engineering
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• 제11권3호
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• pp.79-93
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• 2005

Despite the fact that the sourcing process in B2B e-Marketplaces is one of the most important tasks, the evaluation and selection process of suppliers have been ad-hoc based and mainly dependent on the experience of sourcing managers' subjective knowledge. To remedy the problem, we developed a decision support System (called Wise - I) that helps sourcing managers evaluate suppliers in a more systematic way. The system reflects company's strategy and know-how by adopting company enforced weighted scores for different factors and employing a more scientific method of considering factors other than price and on-time delivery rate, utilizing the AHP method. This paper reports the effectiveness of the system as well as the detailed description of the system. To investigate the effectiveness of the system, we collected information through interview and questionnaire survey. The information was also augmented through the firm key index system, which monitors average delivery lead time and on-time delivery rate. The result indicates that the system leads to the efficiency of purchasing section and the transparency of buying process, therefore reduces delivery time and cost.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제10권7호
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• pp.3286-3300
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• 2016

High Efficiency Video Coding (HEVC) Standard, as the latest coding standard, introduces satisfying compression structures with respect to its predecessor Advanced Video Coding (H.264/AVC). The new coding standard can offer improved encoding performance compared with H.264/AVC. However, it also leads to enormous computational complexity that makes it considerably difficult to be implemented in real time application. In this paper, based on machine learning, a fast partitioning method is proposed, which can search for the best splitting structures for Intra-Prediction. In view of the video texture characteristics, we choose the entropy of Gray-Scale Difference Statistics (GDS) and the minimum of Sum of Absolute Transformed Difference (SATD) as two important features, which can make a balance between the computation complexity and classification performance. According to the selected features, adaptive decision trees can be built for the Coding Units (CU) with different size by offline training. Furthermore, by this way, the partition of CUs can be resolved as a binary classification problem. Experimental results have shown that the proposed algorithm can save over 34% encoding time on average, with a negligible Bjontegaard Delta (BD)-rate increase.

• 경영과학
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• 제24권2호
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• pp.157-176
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• 2007

Fuzzy cognitive map(FCM) has long been used as an effective way of constructing the human's decision making process explicitly. By taking advantage of this feature, FCM has been extensively used in providing what-if solutions to a wide variety of business decision making problems. In contrast, the goal-seeking analysis mechanism by using the FCM is rarely observed in literature, which remains a research void in the fields of FCM. In this sense, this study proposes a new type of the FCM-based goal-seeking analysis which is based on utilizing the genetic algorithm. Its main recipe lies in the fact that the what-if analysis as well as goal-seeking analysis are enabled very effectively by incorporating the genetic algorithm into the FCM-driven inference process. To prove the empirical validity of the proposed approach, valid questionnaires were gathered from a number of experts on software sales, and analyzed statistically. Results showed that the proposed approach is robust and significant.

• Spatial Information Research
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• 제15권3호
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• pp.311-322
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• 2007

시각적 공간분석학은 인간의 공간인지 및 분석 능력을 최대한 발휘할 수 있는 다양한 시각화 도구를 개발함으로써 복잡한 시공간 데이터를 효율적으로 분석하는 학문으로, 궁극적으로는 인간의 추론능력과 시각적 분석도구의 효과적인 융합을 목적으로 한다. 시각적 공간분석학은 최적의 의사결정지원 도구를 개발하는 방법론으로 그 활용 범위가 매우 넓은데, 최근에는 지리적 시각화의 연구 전통을 계승하여 새로운 시각화 도구를 개발하고 다양한 분석을 통해 그 유용성을 확인하는 연구들이 시작되고 있다. 본 연구는 최근에 제안된 시각화 도구인 T 산포도와 전산분석법을 통합하여 우리나라 지역별 수출화물 발생패턴을 7개 유형으로 분석함으로써, 향후 공간의사결정 지원과정에서 시각적 공간분석학의 다양한 활용 가능성을 제시해주고 있다.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2009년도 춘계 학술논문 발표대회 학계
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• pp.189-193
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• 2009

As large-scale buildings, skyscrapers, and multi-purpose buildings recently increase in numbers dramatically the internal space of such buildings becomes more and more large and complicated accordingly. The Multi-purpose buildings are increasing rapidly in number, and concerns over the evacuation process in case of fire emergency are also increasing. However, A controller who is responsible for visitor's safety makes a decision about measures for visitor safety in human based decision making process. Many potential accidents that are caused by human error lurk in results of the process. The accidents can be decreased by changing the decision making process from human-based into technology-based. Through this study, the way to improve current disasters prevention system is presented and it can also improve shelter inducement methods effectively. SICS(Spatial Information Control System) which is being studied in other research is used as the tool for improvement.

• 한국지능시스템학회논문지
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• 제9권4호
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• pp.367-374
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• 1999

본 논문은 대규모 데이터베이스에서 의사 결정을 위한 지식을 효율적으로 추출하기 위해 개념 상승과 속성 감축에 기반한 통합적 방법을 제안한다. 본 방법은 클리스터링 기법에 의해 개념 트리를 자동생성하고 개념 상승기법에 의해 데이터 베이스를 일반화하며 속성의 중요도를 사용한 속성 감축에 의해 최적감축을 하고 식별가능 행렬과 함수를 사용하여 효율적으로 속성값을 감축하여 최적의 최소결정 규칙을 유도한다. 본 방법은 투자 계획이나 가격 결정과 같은 의사결정 업무 각종 고장 진단이나 의료 진단을 위한 지식 베이스구축 마케팅 분석이나 실험 데이터 분석 고수준의 질의 에 의한 정보검색 등에 효과적으로 사용될수 있다.