• Title/Summary/Keyword: Neighborhood systems

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Cooperative Case-based Reasoning Using Approximate Query Answering (근사질의 응답기능을 이용한 협동적 사례기반추론)

  • 김진백
    • The Journal of Information Systems
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    • v.8 no.1
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    • pp.27-44
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    • 1999
  • Case-Based Reasoning(CBR) offers a new approach for developing knowledge based systems. CBR has several research issues which can be divided into two categories : (1) static issues and (2) dynamic issues. The static issues are related to case representation scheme and case data model, that is, focus on casebase which is a repository of cases. The dynamic issues, on the other hand, are related to case retrieval procedure and problem solving process, i.e. case adaptation phase. This research is forcused on retrieval procedure Traditional query processing accepts precisely specified queries and only provides exact answers, thus requiring users to fully understand the problem domain and the casebase schema, but returning limited or even null information if the exact answer is not available. To remedy such a restriction, extending the classical notion of query answering to approximate query answering(AQA) has been explored. AQA can be achieved by neighborhood query answering or associative query answering. In this paper, neighborhood query answering technique is used for AQA. To reinforce the CBR process, a new retrieval procedure(cooperative CBR) using neighborhood query answering is proposed. An neighborhood query answering relaxes a query scope to enlarge the search range, or relaxes an answer scope to include additional information. Computer Aided Process Planning(CAPP) is selected as cooperative CBR application domain for test. CAPP is an essential key for achieving CIM. It is the bridge between CAD and CAM and translates the design information into manufacturing instructions. As a result of the test, it is approved that the problem solving ability of cooperative CBR is improved by relaxation technique.

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L-filters and L-filter convergence

  • Ko, Jung-Mi;Kim, Yong-Chan
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.9 no.1
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    • pp.59-64
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    • 2009
  • In this paper, we study the relations between L-fuzzy topologies and L-filters on a strictly two-sided, commutative quantale lattice L. We define an L-fuzzy neighborhood filter and introduce the notion of L-filter convergence in L-fuzzy topological spaces.

Receding Horizon Control of Nonlinear Systems: Robustness and Effects of Disturbance (비선형 시스템에 대한 동적 구간 제어법:강인성 및 외란의 영향)

  • 양현석
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.33B no.10
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    • pp.1-11
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    • 1996
  • In this paper, a robust receding horizon control algorithm, which can be employed for a wide class of nonlinear systems with control and state constraints, modeling errors, and disturbances, is considered. In a neighborhood of the origin, a linear feedback controlelr for the linearized system is applied. Outside this neighborhood, a receding horizon control is applied. Robust stability is proved considering the time taken to solve an optimal control problem so that the proposed algorithm can be applied as an on-line controller.

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Double Fuzzy Preproximity Spaces

  • Zahran, Ahmed M.;Abd-Allah, M. Azab;El-Saady, Kamal;El-Rahman, Abd El-Nasser G. Abd
    • International Journal of Fuzzy Logic and Intelligent Systems
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    • v.7 no.4
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    • pp.249-255
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    • 2007
  • In this paper, we introduce the concept of double fuzzy preproximity spaces as a generalization of a fuzzy preproximity spaces and investigate some of their properties. Also we study the relationships between double fuzzy preproximity spaces, double fuzzy topological spaces and double fuzzy closure spaces. In addition to this was the introduction of the concept of double fuzzy neighborhood system and has been studying the connection with double fuzzy preproximity, which resulted in the definition of the concept double fuzzy preproximal neighborhood.

A Restricted Neighborhood Generation Scheme for Parallel Machine Scheduling (병렬 기계 스케줄링을 위한 제한적 이웃해 생성 방안)

  • Shin, Hyun-Joon;Kim, Sung-Shick
    • IE interfaces
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    • v.15 no.4
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    • pp.338-348
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    • 2002
  • In this paper, we present a restricted tabu search(RTS) algorithm that schedules jobs on identical parallel machines in order to minimize the maximum lateness of jobs. Jobs have release times and due dates. Also, sequence-dependent setup times exist between jobs. The RTS algorithm consists of two main parts. The first part is the MATCS(Modified Apparent Tardiness Cost with Setups) rule that provides an efficient initial schedule for the RTS. The second part is a search heuristic that employs a restricted neighborhood generation scheme with the elimination of non-efficient job moves in finding the best neighborhood schedule. The search heuristic reduces the tabu search effort greatly while obtaining the final schedules of good quality. The experimental results show that the proposed algorithm gives better solutions quickly than the existing heuristic algorithms such as the RHP(Rolling Horizon Procedure) heuristic, the basic tabu search, and simulated annealing.

Synthesis of Symmetric 1-D 5-neighborhood CA using Krylov Matrix (Krylov 행렬을 이용한 대칭 1차원 5-이웃 CA의 합성)

  • Cho, Sung-Jin;Kim, Han-Doo;Choi, Un-Sook;Kang, Sung-Won
    • The Journal of the Korea institute of electronic communication sciences
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    • v.15 no.6
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    • pp.1105-1112
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    • 2020
  • One-dimensional 3-neighborhood Cellular Automata (CA)-based pseudo-random number generators are widely applied in generating test patterns to evaluate system performance and generating key sequence generators in cryptographic systems. In this paper, in order to design a CA-based key sequence generator that can generate more complex and confusing sequences, we study a one-dimensional symmetric 5-neighborhood CA that expands to five neighbors affecting the state transition of each cell. In particular, we propose an n-cell one-dimensional symmetric 5-neighborhood CA synthesis algorithm using the algebraic method that uses the Krylov matrix and the one-dimensional 90/150 CA synthesis algorithm proposed by Cho et al. [6].

Improving Neighborhood-based CF Systems : Towards More Accurate and Diverse Recommendations (추천의 정확도 및 다양성 향상을 위한 이웃기반 협업 필터링 추천시스템의 개선방안)

  • Kwon, YoungOk
    • Journal of Intelligence and Information Systems
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    • v.18 no.3
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    • pp.119-135
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    • 2012
  • Among various recommendation techniques, neighborhood-based Collaborative Filtering (CF) techniques have been one of the most widely used and best performing techniques in literature and industry. This paper proposes new approaches that can enhance the neighborhood-based CF techniques by identifying a few best neighbors (the most similar users to a target user) more accurately with more information about neighbors. The proposed approaches put more weights to the users who have more items co-rated by the target user in similarity computation, which can help to better understand the preferences of neighbors and eventually improve the recommendation quality. Experiments using movie rating data empirically demonstrate simultaneous improvements in both recommendation accuracy and diversity. In addition to the typical single rating setting, the proposed approaches can be applied to the multi-criteria rating setting where users can provide more information about their preferences, resulting in further improvements in recommendation quality. We finally introduce a single metric that measures the balance between accuracy and diversity and discuss potential avenues for future work.

Comparison of Spatial Small Area Estimators Based on Neighborhood Information Systems (이웃정보시스템을 이용한 공간 소지역 추정량 비교)

  • Kim, Jeong-Suk;Hwang, Hee-Jin;Shin, Key-Il
    • The Korean Journal of Applied Statistics
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    • v.21 no.5
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    • pp.855-866
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    • 2008
  • Recently many small area estimation methods using the lattice data analysis have been studied and known that they have good performances. In the case of using the lattice data which is mainly used for small area estimation, the choice of better neighborhood information system is very important for the efficiency of the data analysis. Recently Lee and Shin (2008) compared and analyzed some neighborhood information systems based on GIS methods. In this paper, we evaluate the effect of various neighborhood information systems which were suggested by Lee and Shin (2008). For comparison of the estimators, MSE, Coverage, Calibration, Regression methods are used. The number of unemployment in Economic Active Population Survey(2001) is used for the comparison.

A Fast CU Size Decision Optimal Algorithm Based on Neighborhood Prediction for HEVC

  • Wang, Jianhua;Wang, Haozhan;Xu, Fujian;Liu, Jun;Cheng, Lianglun
    • Journal of Information Processing Systems
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    • v.16 no.4
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    • pp.959-974
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    • 2020
  • High efficiency video coding (HEVC) employs quadtree coding tree unit (CTU) structure to improve its coding efficiency, but at the same time, it also requires a very high computational complexity due to its exhaustive search processes for an optimal coding unit (CU) partition. With the aim of solving the problem, a fast CU size decision optimal algorithm based on neighborhood prediction is presented for HEVC in this paper. The contribution of this paper lies in the fact that we successfully use the partition information of neighborhood CUs in different depth to quickly determine the optimal partition mode for the current CU by neighborhood prediction technology, which can save much computational complexity for HEVC with negligible RD-rate (rate-distortion rate) performance loss. Specifically, in our scheme, we use the partition information of left, up, and left-up CUs to quickly predict the optimal partition mode for the current CU by neighborhood prediction technology, as a result, our proposed algorithm can effectively solve the problem above by reducing many unnecessary prediction and partition operations for HEVC. The simulation results show that our proposed fast CU size decision algorithm based on neighborhood prediction in this paper can reduce about 19.0% coding time, and only increase 0.102% BD-rate (Bjontegaard delta rate) compared with the standard reference software of HM16.1, thus improving the coding performance of HEVC.

A Stigmergy-and-Neighborhood Based Ant Algorithm for Clustering Data

  • Lee, Hee-Sang;Shim, Gyu-Seok
    • Management Science and Financial Engineering
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    • v.15 no.1
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    • pp.81-96
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    • 2009
  • Data mining, specially clustering is one of exciting research areas for ant based algorithms. Ant clustering algorithm, however, has many difficulties for resolving practical situations in clustering. We propose a new grid-based ant colony algorithm for clustering of data. The previous ant based clustering algorithms usually tried to find the clusters during picking up or dropping down process of the items of ants using some stigmergy information. In our ant clustering algorithm we try to make the ants reflect neighborhood information within the storage nests. We use two ant classes, search ants and labor ants. In the initial step of the proposed algorithm, the search ants try to guide the characteristics of the storage nests. Then the labor ants try to classify the items using the guide in-formation that has set by the search ants and the stigmergy information that has set by other labor ants. In this procedure the clustering decision of ants is quickly guided and keeping out of from the stagnated process. We experimented and compared our algorithm with other known algorithms for the known and statistically-made data. From these experiments we prove that the suggested ant mining algorithm found the clusters quickly and effectively comparing with a known ant clustering algorithm.