• 제목/요약/키워드: Selection Process

검색결과 3,336건 처리시간 0.189초

휴리스틱 기법을 활용한 PCB 자동삽입라인의 작업흐름경로선택기법 (Heuristic Job Route Selection of PCB Auto-insertion Line)

  • 한성배;조현규;함호상;우훈식;김중배
    • 산업공학
    • /
    • 제8권3호
    • /
    • pp.259-267
    • /
    • 1995
  • A printed circuit board auto-insertion line consists of several processes of identical machines and produces several different types of PCBs. Each board must be processed by at most one machine in each process. So, we call it a flexible flow line. The load balancing is the one of the most important issues in the FFL which has many sequential processes. Therefore we have represented the job route selection model to balance the load of inter-process in the PCB auto-insertion line, and validated it by simulation.

  • PDF

계층화의사결정법(AHP)을 이용한 전투기의 기종선정에 관한 연구 (A Study on the Application of Analytic Hierarchy Process to the selection of Fighter Plane)

  • 은희봉;김봉선
    • 한국항공운항학회지
    • /
    • 제6권1호
    • /
    • pp.51-69
    • /
    • 1998
  • This paper was studied to present a model for the application of AHP to the selection of fighter planes. For this study, a questionnaire was developed in respect to the criteria of fighter plane and given to 70 reserved officers who had experienced as fighter pilots in Republic of Korean Air Force (ROKAF) to ask their opinions about the candidates for the next-generation fighter planes of the ROKAF. The AHP software developed by Korean Advanced Institute of Science Technology (KAIST) was used to process the data. The result was analyzed by the criteria of selecting military aircraft and the several alternatives for the next-generation fighter planes.

  • PDF

유연한 셀생산을 위한 최적가공경로와 생산조건의 결정 (Optimization Analysis of Flexible Cellular Manufacturing: Route Selection and Determining the Optimal Production Conditions for Ordered Products)

  • 송상재;최정희
    • 대한산업공학회지
    • /
    • 제18권1호
    • /
    • pp.47-62
    • /
    • 1992
  • This paper describes a procedure for optimizing the route selection and production conditions in alternate process plans under a cellular manufacturing environment. The type of production is mainly production-to-order which deals with unexpected products as the changes factor. The flexible cellular manufacturing can be viewed as a complete unification of both flexible manufacturing process and flexible production management. The integrated problem for designing flexible cellular manufacturing associated with determining the optimal values of the machining speeds, overtime, and intercell flow is formulated as Nonlinear Mixed Integer Programming(NMIP) in order to minimize total production change cost. This is achieved by introducing the marginal cost analysis into the NMIP, which will compute the optimal machining speed, overtime, intercell flow, and routing. The application of this procedure offers greater flexibility to take advantage of the cellular manufacturing due to the optimum use of resources. A solution procedure for this problem was developed and a numerical example is included.

  • PDF

중복된 칼라 히스토그램과 공간 정보를 이용한 내용 기반 화상 검색 시스템 설계 및 구현 (LDesign and implementation of a content-based image retrieval system using the duplicated color histogram and spatial information)

  • 김철원;최기호
    • 한국통신학회논문지
    • /
    • 제22권5호
    • /
    • pp.889-898
    • /
    • 1997
  • Most general content-based image retrieval techniques use color and texture as retrieval indices. Spatial information is not used to color histogram and color pair based on color retrieval techniques. This paper proposes the selection of a set of representative in the duplicated color histogram, the analysis of spatial information of the selected colors and the image retrieval process based on the duplicated color histogram and spatial information. Two color historgrams for background and object are used in order to decide on color selection in the duplicated color histogram. Spatial information is obtained using a maximum entropy discretization. A retrieval process applies to duplicated color histogram and spatial to retrieve input images and relevant images. As the result of experiment of the image retrieval, improved color his togram and spatial information method hs increased the retrieval effectiveness more the color histogram method and color pair method.

  • PDF

창발적 기계설계를 위한 컴퓨터기반 프레임워크 (Framework for Innovative Mechanical Design Using Simulated Emergent Evolution)

  • 이인호;차주헌;김재정
    • 대한기계학회논문집A
    • /
    • 제26권4호
    • /
    • pp.701-710
    • /
    • 2002
  • The framework, described in this paper, involves artificial evolutionary systems that re -produce aimed solutions through a simulated Darwinian evolution process. Through this process the framework designs structures of machines innovatively and emergently especially in the stages of conceptual and basic design. Since the framework simulates the evolution of nature, it inevitably involves processes that converse the natural evolution to the artificial evolution. For the conversion, based on several methods as the building block modeling, Artificial Life, evolutionary computation and the law of natural selection, we propose a series of processes that consists of modeling, evaluation, selection, evolution etc. We have demonstrated the implementation of the framework with the design of multi-step gear systems.

Whole genome sequencing of Luxi Black Head sheep for screening selection signatures associated with important traits

  • Liu, Zhaohua;Tan, Xiuwen;Wang, Jianying;Jin, Qing;Meng, Xianfeng;Cai, Zhongfeng;Cui, Xukui;Wang, Ke
    • Animal Bioscience
    • /
    • 제35권9호
    • /
    • pp.1340-1350
    • /
    • 2022
  • Objective: Luxi Black Head sheep (LBH) is the first crossbreed specialized for meat production and was developed by crossbreeding Black Head Dorper sheep (DP) and Small Tailed Han sheep (STH) in the farming areas of northern China. Research on the genomic variations and selection signatures of LBH caused by continuous artificial selection is of great significance for identifying the genetic mechanisms of important traits of sheep and for the continuous breeding of LBH. Methods: We explored the genetic relationships of LBH, DP, and several Mongolian sheep breeds by constructing phylogenetic tree, principal component analysis and linkage disequilibrium analysis. In addition, we analysed 29 whole genomes of sheep. The genome-wide selection signatures have been scanned with four methods: heterozygosity (HP), fixation index (FST), cross-population extended haplotype homozygosity (XP-EHH) and the nucleotide diversity (𝜃π) ratio. Results: The genetic relationships analysis showed that LBH appeared to be an independent cluster closer to DP. The candidate signatures of positive selection in sheep genome revealed candidate genes for developmental process (HoxA gene cluster, BCL2L11, TSHR), immunity (CXCL6, CXCL1, SKAP2, PTK6, MST1R), growth (PDGFD, FGF18, SRF, SOCS2), and reproduction (BCAS3, TRIM24, ASTL, FNDC3A). Moreover, two signalling pathways closely related to reproduction, the thyroid hormone signalling pathway and the oxytocin signalling pathway, were detected. Conclusion: The selective sweep analysis of LBH genome revealed candidate genes and signalling pathways associated with developmental process, immunity, growth, and reproduction. Our findings provide a valuable resource for sheep breeding and insight into the mechanisms of artificial selection.