• 제목/요약/키워드: decision problem

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블록 부호에 대한 효율적인 연판정 복호기법 (An Efficient Soft Decision Decoding Method for Block Codes)

  • 심용걸
    • 한국멀티미디어학회논문지
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    • 제7권1호
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    • pp.73-79
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    • 2004
  • 본 논문에서는 선형 블록 부호에 대한 효율적인 연판정 복호 알고리듬을 제안하였다. 종래 의 연판정 복호기는 그 연판정 값을 추정하기 위하여 경판정 복호를 여러 번 수행해야 한다. 그러나 종래의 방법으로는 후보 부호어들이 구해지지 않을 수도 있으며, 그렇게 되면 연판정 값을 얻기가 매우 어려워진다. 본 논문에서는 후보 부호어들을 탐색하는 효율적인 알고리듬을 도입하여 이 문제를 해결하였다. 이 방법을 사용하면 후보 부호어가 찾아지지 않을 가능성을 대폭 감소시킬 수 있다. 시뮬레이션을 통하여 제안된 알고리듬의 성능을 확인할 수 있었다. 페이딩 채널에서 2진 (63, 36) BCH 부호에 대하여 시뮬레이션을 수행하였다.

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복잡한 조직에서의 의사결정과 학습 -쓰레기통 모형(Garbage Can Model)의 학습 적용- (Decision Making and Learning in Complex Organization : Learning Approach of Garbage Can Model)

  • 오영민;정경호
    • 한국시스템다이내믹스연구
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    • 제9권1호
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    • pp.57-71
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    • 2008
  • This research paper describes a complex and vague settings in which organization makes a decision and explains a role of decision maker's learning process. The original paper, written by Cohen, March, Olsen in 1972, said that all members of organization depended on the technology taken through trials and errors, which is the 'learning' process literally. But they intended to exclude the learning process in their simulation model because their PORTRAN model couldn't replicate the learning concept. As a result, they couldn't explain how all agents of garbage can simulation model resolve the problem dynamically. To overcome this original paper's limitations, we try to rebuild a learning process simulation model using by system dynamics approach that can capture the linkage between organization leanings and agents-based decision-makings. Our learning simulation results reveal two points. First, decision maker's leanings process improves the efficiency of decision making in complex situation. Second, group learning shows a superior efficiency to an individual learning because group members share organizational memory and energy.

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성호종속을 허용하는 다속성 의사결정문제의 대화형 접근방법 (An Interactive Approach to Select Optimal Solution for MADM Problems with Preferential Dependence)

  • 이강인;조성구
    • 한국경영과학회지
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    • 제20권2호
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    • pp.61-76
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    • 1995
  • The "optimal" solution for a decision making problem should be the one that best reflects the decision-maker's preference. For MADM (Multi-Attribute Decision-Making) problems, however, finding an optimal solution is difficult, especially when the number of alternatives, or that of attributes is relatively large. Most of the existing mathematical approaches arrive at a final solution on the basis of many unrealistic assumptions, without reflecting the decision-maker's preference structure exactly. To remedy this, some interactive methods have been proposed, but most of them require a large amount of information growing exponentially as the number of alternatives, or that of attributes increases. Therefore it is difficult for the decision-maker to maintain consistency throughout the decision making process. In this paper, an interactive method which finds optimal solutions for deterministic MADM problems with many attributes and alternatives is proposed. Instead of considering all the attributes simultaneously, this method partitions all the attributes into several mutually independent subgroups and considers one of them at each of preordered steps, where the alternatives are eliminated until the optimal one is obtained. The efficiency of the method lies in the fact that the amount of neccessary information is reduced significantly, and even further if a suboptimal solution is acceptable to the decision-maker.ion-maker.

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Automation of Decision-Making in the Game "Ecopoly" for Education on Relationship between Environment and Economy

  • Komuro, Tatsuya;Shinozaki, Ayano;Kim, Aramu;Doyo, Daisuke;Matsumoto, Toshiyuki
    • Industrial Engineering and Management Systems
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    • 제11권1호
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    • pp.123-132
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    • 2012
  • Recently, global environmental problems have become serious due to human economic activities. Therefore, in order to build a sustainable society in which human economic activities coexist with nature, it is important to promote and enhance environmental education. As a preceding study, a board and computer game of "Ecopoly," which is the game for education on global environmental problems, were developed. This study further aims to develop algorithms which make decisions in Ecopoly, to automate decision-makings of opponents using the algorithms, and to develop the environmental educational game "Ecopoly V" which enables self-learning. In order to develop the algorithms, the board game of Ecopoly was played, and each player's decision-makings at the all points at which players make a decision were observed and analyzed. From the analyses, it became clear that the decision-makings were distinguished by 3 characteristics; Ecology type, Economy type, and Balance type. Based on the characteristics, the factors and standard values of each decision-making were made clear. Algorithms were developed based on the factors and standard values. Ecopoly V was developed by incorporating the algorithms into the computer game of Ecopoly. Experimental testing of the game was conducted and the validity of the game was verified.

AHP 및 Fuzzy 의사결정 모형을 활용한 반도체 장치라인의 CTP 선정 방법론 개발 (Development of CTP Selection Methodology of Semiconductor Equipment Line Using AHP and Fuzzy Decision Model)

  • 정재환;김정섭;김여진;이종환
    • 반도체디스플레이기술학회지
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    • 제20권2호
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    • pp.6-13
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    • 2021
  • Cases and studies on the selection method of CTQ are relatively active, but there are few cases or studies on the selection method of CTP which is important in the device industry. In fact, many companies simply select and manage CTP from the point of contact based on their experience and intuition. The purpose of this study is to present an evaluation model and a mathematical decision model for rational and systematic CTP selection to improve the process quality of semiconductor equipment lines. In the evaluation model, AHP (Analytic Hierarchy Process) analysis technique was applied to show objective and quantitative figures, and Fuzzy decision-making model was used to solve the ambiguity and uncertainty in the decision-making process. Decision Value (DV) was presented. The subjects were 22 process factors managed in the Plating Process that the representative equipment line can do. As a result, the evaluation model proposed in this study can support more efficient and effective decision-making for process quality improvement by more objectively measuring the problem of subjective CTP selection in manufacturing sites.

A cross-domain access control mechanism based on model migration and semantic reasoning

  • Ming Tan;Aodi Liu;Xiaohan Wang;Siyuan Shang;Na Wang;Xuehui Du
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • 제18권6호
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    • pp.1599-1618
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    • 2024
  • Access control has always been one of the effective methods to protect data security. However, in new computing environments such as big data, data resources have the characteristics of distributed cross-domain sharing, massive and dynamic. Traditional access control mechanisms are difficult to meet the security needs. This paper proposes CACM-MMSR to solve distributed cross-domain access control problem for massive resources. The method uses blockchain and smart contracts as a link between different security domains. A permission decision model migration method based on access control logs is designed. It can realize the migration of historical policy to solve the problems of access control heterogeneity among different security domains and the updating of the old and new policies in the same security domain. Meanwhile, a semantic reasoning-based permission decision method for unstructured text data is designed. It can achieve a flexible permission decision by similarity thresholding. Experimental results show that the proposed method can reduce the decision time cost of distributed access control to less than 28.7% of a single node. The permission decision model migration method has a high decision accuracy of 97.4%. The semantic reasoning-based permission decision method is optimal to other reference methods in vectorization and index time cost.

An Integrated AHP-VIKOR Methodology for Facility Layout Design

  • Shokri, Hamidreza;Ashjari, Behzad;Saberi, Morteza;Yoon, Jin Hee
    • Industrial Engineering and Management Systems
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    • 제12권4호
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    • pp.389-405
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    • 2013
  • A facility layout design (FLD) problem can be generally introduced as assignment of facilities (departments) to a site such that a set of criteria are satisfied or some objectives are minimized (maximized). Hence, it can be considered as a multi-criteria problem due to the presence of qualitative criteria such as maintenance or flexibility and quantitative criteria such as the total cost of handling material. The VIKOR method was developed to solve multiple criteria decision making problems with conflicting and non-commensurable (different units) criteria, assuming that compromising is acceptable for conflict resolution, the decision maker wants a solution that is the closest to the ideal, and the alternatives are evaluated according to all established criteria. This paper proposes a hierarchical analytic hierarchy process (AHP) and VIKOR approach to solve the FLD problem. A computer-aided layout-planning tool is adopted to generate the facility layout problems, as well as their quantitative data. The qualitative performance measures are weighted by AHP. VIKOR is then used to solve the FLD problem. Finally, the proposed integrated procedure is applied to three real-time examples.

유전자 알고리즘을 활용한 데이터 불균형 해소 기법의 조합적 활용

  • 장영식;김종우;허준
    • 한국지능정보시스템학회:학술대회논문집
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    • 한국지능정보시스템학회 2007년도 한국지능정보시스템학회
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    • pp.309-320
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    • 2007
  • The data imbalance problem which can be uncounted in data mining classification problems typically means that there are more or less instances in a class than those in other classes. It causes low prediction accuracy of the minority class because classifiers tend to assign instances to major classes and ignore the minor class to reduce overall misclassification rate. In order to solve the data imbalance problem, there has been proposed a number of techniques based on resampling with replacement, adjusting decision thresholds, and adjusting the cost of the different classes. In this paper, we study the feasibility of the combination usage of the techniques previously proposed to deal with the data imbalance problem, and suggest a combination method using genetic algorithm to find the optimal combination ratio of the techniques. To improve the prediction accuracy of a minority class, we determine the combination ratio based on the F-value of the minority class as the fitness function of genetic algorithm. To compare the performance with those of single techniques and the matrix-style combination of random percentage, we performed experiments using four public datasets which has been generally used to compare the performance of methods for the data imbalance problem. From the results of experiments, we can find the usefulness of the proposed method.

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트리의 최적 경로 분할을 위한 다항시간 알고리즘 (A Polynomial-time Algorithm to Find Optimal Path Decompositions of Trees)

  • 안형찬
    • 한국정보과학회논문지:시스템및이론
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    • 제34권5_6호
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    • pp.195-201
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    • 2007
  • 트리의 최소단말경로분할이란 트리를 에지가 서로 소인 단말 노드 간 경로들로 분할하되, 가장 긴 경로의 길이를 최소화하는 문제이다. 본 논문에서는 트리의 최소단말경로분할을 $O({\mid}V{\mid}^2$시간에 구하는 알고리즘을 제시한다. 이 알고리즘은 주어진 최적화 문제를 이에 대응하는 결정 문제, 즉 최소단말경로 분할의 비용이 l 이하인지를 결정하는 문제를 이용한 이진 탐색으로 환원한다. 결정 문제는 트리를 한 차례 순회하는 동안 동적 계획법에 의해 해결된다

모델베이스 설계를 위한 개념적 모델링 도구에 관한 연구 (A Conceptual Modeling Tools for the Model Base Design)

  • 정대율
    • 한국정보시스템학회지:정보시스템연구
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    • 제7권1호
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    • pp.181-208
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    • 1998
  • In many literatures of model management, various schemes for representing model base schema have proposed. Ultimately, the goal is to arrive at a set of mutually supportive and synergistic methodologies and tools for the modeling problem domain and model base design. This paper focus on how best to structure and represent conceptual model of problem domain and schema of model base. Semantic concepts and modeling constructs are valuable conceptual tools for understanding the structural relationships and constraints involved in an model management environment. To this end, we reviewed the model management literature, and analyzed the constructs of modeling tools of data model management graph-based approach. Although they have good tools but most of them are not enough for the representation of structural relationships and constraints. So we wanted more powerful tools which can represent diverse constructs in a decision support modeling and model base schema design. For the design of a model base, we developed object modeling framework which uses Object Modeling Techniques (OMT). In Object Modeling Framework, model base schema are classified into conceptual schema, logical schema, and physical schema. The conceptual schema represents the user's view of problem domain, and the logical schema represents a model formatted by a particular modeling language. The schema design, this paper proposes an extension of Object Model to overcome some of the limitations exhibited by the OMT. The proposed tool, Extended Object Model(EOM) have diverse constructs for the representation of decision support problem domain and conceptual model base schema.

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