• The KIPS Transactions:PartB
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• v.12B no.4 s.100
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• pp.413-420
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• 2005

In this paper, we apply software agents, which use fuzzy logic and make autonomous decisions according to state transitions, to car driving environment. We carry out an experiment on artificial intelligent car driving in terms of real-time reactive agents. Inference techniques for constructing real-time reactive agents consider the settings with max-product inference, n-fuzzy rules, and n-associatives ($A_l,\;B_l),\;{\ldots}(A_n,\;B_n$). Then we perform defuzzification processes, extract a central value, and work out inference processes.

• Proceedings of the Korea Water Resources Association Conference
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• 2017.05a
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• pp.108-108
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• 2017

깊은 불확실성이 내재되어 있는 기후변화의 특성을 고려한 의사결정은 강건함(Robustness)의 특성을 지니고 있어야 한다. 강건한(Robust) 의사결정은 광범위한 불확실성의 상황에서 모든 요구사항을 충족시키는 전략을 제시한다. 이러한 강건함의 개념은 저수지운영 규칙 산정에 필요한 최적화 과정에도 적용될 수 있는데, 이를 로버스트(Robust) 최적화 과정이라고 한다. 로버스트 최적화 과정은 기존 최적화과정이 현재의 자료를 바탕으로 최적의 해를 찾기 때문에 미래 입력자료의 불확실성을 반영하지 못하는 한계를 극복하기 위하여 등장하였다. 로버스트 최적화 과정은 크게 두 가지 방법으로 나눌 수 있는데, 확률적 로버스트 최적화 방법과 비확률적 로버스트 최적화 방법이다. 확률적 로버스트 최적화 과정은 전통적인 최적화 과정과 동일하게 불확실 변수의 확률분포를 가정하지만, 비확률적 로버스트 최적화 과정은 불확실 변수의 확률분포를 가정하지 않는다. 본 연구는 최근 수자원의 부족을 겪었던 보령댐의 보다 안정적인 이수기 운영방안 산정을 위해 로버스트 최적화 과정을 적용하였다. 먼저 전통적인 최적화 방법을 적용하여 운영방안을 도출한 뒤 기후변화 상황에서의 취약성, 신뢰성, 지속가능성 그리고 회복탄력성 등을 검토하였다. 다음으로 이에 대한 대안으로 로버스트 최적화 방법으로 운영방안을 산출하였으며 이를 기존의 최적화방법과 여러 기준으로 비교하여 그 타당성을 검토하였다. 또한 두 가지 로버스트 최적화 방법을 비교하여 각 과정의 장단점에 대해 논의 하였으며, 어떤 최적화 과정이 댐 운영방안 산정에 있어 보다 합리적이고 타당한지 비교하였다. 본 연구의 결과를 통해, 기후변화의 영향 하에서 보다 안정적인 수자원 관리 방안을 제안할 수 있었다.

• The Journal of Korean Association of Computer Education
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• v.16 no.2
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• pp.61-68
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• 2013

SNS is a social networking service that helps people to have a two-way communication, manage their personal relationships and share information. The domestic and international SNS markets have attained a steady growth, and their growth is being more accelerated recently. Under these circumstances, immature students are more likely to show negative cyber behavior. This study attempted to analyze the relationship between the use of SNS, motives of SNS use, the use of active SNS functions, SNS-dependency and views in SNS and negative SNS behaviors among elementary and middle school students. For this, negative cycber behaviors are classified into four stages depending on the severity, for each of which distribution of factors is investigated and the combination of factors to determine each stage is obtained through association rule analysis. As a result, it is found that 85% of the students rarely show negative cyber behaviors, stealing personal information and contacting with strangers are the most frequent negative behaviors, and students with a great dependency on SNS are highly probable to show negative behaviors.

• Journal of Advanced Marine Engineering and Technology
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• v.39 no.3
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• pp.298-305
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• 2015

This paper provides experimental results of an excitation control system of the synchronous generator on board ships in accordance with rules of classification society to make sure its performance. The experiment compares and reviews control results between PID control and fuzzy logic control applied to change of loads of the generator in order to make sure to satisfy the rules of classification society. Both of them are written by Labview program. In case of PID Control, this paper firstly adjusts the gains by ultimate sensitive method and the gains is more tuned by engineer's experience. And the fuzzy logic controller uses Mamdani method to make membership function for error between reference voltage and measuring voltage, differential error rate and output voltage. This paper is to make sure the experimental results of the proposed excitation control system applied to actual small synchronous generator with PID control and fuzzy logic written by using Labview program and it is proved on stability and improvement through experiments.

• The Journal of the Korea Contents Association
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• v.5 no.3
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• pp.209-215
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• 2005

In this paper, we describe the answer pattern for definitional question-answering system. The .answer extraction method of a definitional question-answering system is different from the general answer extraction method because it presents the descriptive answer for a definitional question. The definitional answer extraction using the definitional answer pattern can extract the definitional answer correctly without the semantic analysis. The definitional answer pattern is consist of answer pattern, conditional rule and priority to extract the correct definitional answer. We extract the answer pattern from the definitional training corpus and determine the optimum conditional rule using F-measure. Next, we determine the priority of answer patterns using precision and syntactic structure. Our experiments show that our approach results in the precision(0.8207), the recall(0.9268) and the F-measure(0.8705). It means that our approach can be used efficiently for a definitional question-answering system.

• Journal of the Korea Society for Simulation
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• v.27 no.2
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• pp.71-81
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• 2018

Forklifts in a shipyard lift and transport heavy objects. Tasks occur dynamically and the rate of the task occurrence changes over time. Especially, the rate of the task occurrence is high immediately after morning and afternoon business hours. The weight of objects varies according to task characteristic, and a forklift also has the workable or allowable weight limit. In this study, we propose an online forklift dispatching algorithm based on nearest-neighbor dispatching rule using minimal cost assignment approach in order to attain the efficient operations. The proposed algorithm considers various types of forklift and multiple jobs at the same time to determine the dispatch plan. We generate dummy forklifts and dummy tasks to handle unbalance in the numbers of forklifts and tasks by taking their capacity limits and weights. In addition, a method of systematic forklift selection is also devised considering the condition of the forklift. The performance indicator is the total travel distance and the average task waiting time. We validate our approach against the priority rule-based method of the previous study by discrete-event simulation.

• Journal of Korea Water Resources Association
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• v.38 no.9 s.158
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• pp.761-770
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• 2005

This study applied the fuzzy logic control for the construction of the reservoir operation model which can consider uncertainty of the predicted inflow in determining reservoir release during flood period. The control rule is usually constructed based on the opinion of experts which is a general technique. To improve the drawback of general technique, this study constructed the Fuzzy-Tabu search model automatically established by the fuzzy rule using Tabu search which is a global optimization technique. As the results, the peak release is decreased and the flood control efficiency is improved. The total release is also decreased and this represents the benefit in water use. Consequently, it is confirmed that the effect of flood control can be increased through the constructed model. It also shows that the available water resources after the flood is more increased. So, the proposed Fuzzy-Tabu search model could be better than the actual reservoir operation methodology in the aspect of water use.

• The Transactions of the Korean Institute of Electrical Engineers
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• v.39 no.10
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• pp.1108-1120
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• 1990

The present study is to develop an intelligent control system for flexible manufacturing system, which is suitable for a variety of manufacturing types with smaller production rates. The controller is designed to integrate heuristic rules with optimization techniques for loading as well as flow rate of parts and ultimately meeting performance indices. The control function implemented by an optimization technique is to calculate short term production rates of parts. The heuristic control determined by production rules requires knowledge base to evaluate selected loading alternatives according to short term production rate and current process information, and also to determine final decision pertaining to loading. In this case, the knowledge base is constructed using the rules for evaluating alternatives, decision criteria, and flow control of parts in manufacturing system. The database is formulated by means of managing and updating current process information. A graphic system to monitor current status of the function and operation of manufacturing system is developed, and computer simulation is carried out to evaluate the performance of the proposed controller.

• KDI Journal of Economic Policy
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• v.17 no.4
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• pp.3-61
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• 1995

기업활동의 범세계화(汎世界化), WTO 출범 등으로 세계경제(世界經濟)의 통합(統合)과 무국경화(無國境化)가 진행되고 있다. 이에 따라 자본 고급인력 등 국제이동성(國際移動性)이 높은 자원들이 유동화(流動化)할 것이고, 그 결과 토지, 사회간접자본, 미숙련 노동력, '경기규칙', 사회 전반적인 과학기술수준, 문화 등 국제이동성(國際移動性)이 낮은 광의(廣義)의 생산요소(生産要素)들이 한 나라의 경제적 특성을 결정하고 경제 기반을 이룰 것이다. 무국경시대(無國境時代)에는 자원배분뿐 아니라 자원유치(資源幽致)가 한 나라의 경제성과에 큰 영향을 미칠 것이며, 따라서 자원유치가 경제운영의 중요한 과제로 등장할 것으로 예상된다. 자원의 국제적(國際的) 유동화(流動化)는 국제이동성(國際移動性)이 높은 생산요소들이 국제이동성이 낮은 생산요소들을 찾아 경제활동의 근거지를 선택하는 것이므로, 무국경시대(無國境時代)에는 저이동성(低移動性) 생산요소(生産要素)들의 양적(量的) 확충(擴充)및 질적(質的) 수준(水準) 제고(提高)를 통한 자원유치(資源誘致)의 가능성이 커지며, 따라서 일부 첨단기술산업의 육성보다는 전반적인 과학기술(科學技術) 수준(水準) 제고(提高)가, 소수의 고급인력 확보보다는 다수(多數) 미숙련(未熟練) 인력(人力)의 질적(質的) 수준(水準) 제고(提高)가 경제성과를 높이는 데 상대적으로 더 중요해진다. 또한 경제적(經濟的) 무국경화(無國境化)는 국적에 관한 속인주의(屬人主義)의 퇴조와 속지주의(屬地主義)의 보편화, 한 나라 국경 안에 상이한 특성을 가진 지방경제(地方經濟)들의 부상, 국내 산업들 사이의 산업연관관계(産業聯關關係) 약화(弱化) 등의 변화를 수반할 것으로 예상된다. 이같은 변화로 개방주의(開放主義) 및 무차별주의(無差別主義)의 확대(擴大)가 불가피하게 되고 특정 산업에 대한 정부지원 및 보호의 근거가 약화되는 반면, 자원배분의 참고단위로서 개별(個別) 경제주체(經濟主體)들의 중요성이 높아지며 그만큼 시장경쟁을 지배하는 '경기규칙(鏡技規則)'의 올바른 정립이 중요해진다. 그러므로 정부는 자원배분에 대한 개업을 축소하고, 저이동성(低移動性) 생산요소(生産要素)들의 양적 질적 수준 제고, 특히 '경기규칙(競技規則)'의 공정성(公正性) 및 투명성(透明性)을 높여야 한다. 즉 정부가 폐쇄성 높은 경제의 지배인으로부터 개방(開放)된 시장경제(市場經濟)의 후견인으로 바뀌어야 한다. 이것이, 시장질서(市場秩序)가 우리를 먹여 살리는 손이라는 인식이나 국제분업(國際分業)이 살 길이라는 확신이 부족한 우리 사회에 무국경시대(無國境時代)가 던지는 어려운 도전(挑戰)이다.

• Journal of the Korean Institute of Intelligent Systems
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• v.18 no.6
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• pp.842-848
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• 2008

This paper deal with uncertainty problem by using Type-2 fuzzy logic set for nonlinear system modeling. We design Type-2 fuzzy logic system in which the antecedent and the consequent part of rules are given as Type-2 fuzzy set and also analyze the performance of the ensuing nonlinear model with uncertainty. Here, the apexes of the antecedent membership functions of rules are decided by C-means clustering algorithm and the apexes of the consequent membership functions of rules are learned by using back-propagation based on gradient decent method. Also, the parameters related to the fuzzy model are optimized by means of particle swarm optimization. The proposed model is demonstrated with the aid of two representative numerical examples, such as mathematical synthetic data set and Mackey-Glass time series data set and also we discuss the approximation as well as generalization abilities for the model.