• 제목/요약/키워드: total graph

검색결과 246건 처리시간 0.02초

불확실한 환경 하에서 중간 평가가 있는 시간-비용 프로젝트 문제 (Project Time-Cost Tradeoff Problem with Milestones under an Uncertain Processing Time)

  • 최병천;정지복
    • 한국경영과학회지
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    • 제38권2호
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    • pp.25-42
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    • 2013
  • We consider a project time-cost tradeoff problem with two milestones, where one of the jobs has an uncertain processing time. Unless each milestone is completed on time, some penalty cost may be imposed. However, the penalty costs can be avoided by compressing the processing times of some jobs, which requires additional resources or costs. The objective is to minimize the expected total costs subject to the constraint on the expected project completion time. We show that the problem can be solved in polynomial time if the precedence graph of a project is a chain.

SoC를 위한 다단 HW/SW 분할 알고리듬 (A Multi-Level HW/SW Partitioning Algorithm for SoCs)

  • 안병규;신봉식;정정화
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 2004년도 하계종합학술대회 논문집(2)
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    • pp.553-556
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    • 2004
  • In this paper, we present a new efficient multi-level hardware/software partitioning algorithm for system-on-a-chip design. Originally the multi-level partitioning algorithm are proposed to enhance the performance of previous iterative improvement partitioning algorithm for large scale circuits. But when designing very complex and heterogeneous SoCs, the HW/SW partitioning decision needs to be made prior to refining the system description. In this paper, we present a new method, based on multi-level algorithm, which can cover SoC design. The different variants of algorithm are evaluated by a randomly generated test graph. The experimental results on test graphs show improvement average $9.85\%$ and $8.51\%$ in total communication costs over FM and CLIP respectively.

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연결-에지 추가 기법을 이용한 클락 스큐 최적화 (Clock Skew Optimization Using Link-Edge Insertion)

  • 정공옥;류광기신현철정정화
    • 대한전자공학회:학술대회논문집
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    • 대한전자공학회 1998년도 추계종합학술대회 논문집
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    • pp.1009-1012
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    • 1998
  • An efficient algorithm for clock skew optimization is proposed in this paper. It construct a new clock routing topology which is the generalized graph model while previous methods uses tree-structured routing topology. Edge-insertion technique is used in order to reduce the clock skew. A link-edge is inserted repeatedly between two sinks whose delay difference is large and the distance is small. As a result, the delay of a sink which has the longer delay is decreased and the clock skew is reduced. The proposed algorithm is implemented in C programming language. From the experimental results, we can get the total wire length minimization under the given skew bound.

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다중프로세서 시스템에 적합한 우선순위 할당 결정기법에 관한 연구 (Allocation Priority Scheme for Multiprocessor Systems)

  • 박영선;김화수
    • 한국국방경영분석학회지
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    • 제17권2호
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    • pp.113-122
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    • 1991
  • This paper presents the Allocation Priority Scheme (APS) for multiprocessor system. The objective of APS is to reduce the time-complexity on a Physical Mapping Scheme(PMS). The PMS is to allocate the nodes of the Data Dependency Graph (DDG) to the multprocessors efficiently and effectively. The APS provides the priority to each node (vertex) in the DDG. In other words, the goal of the APS is to find a request resource mapping such that the total cost (time-complexity) is minimized. The special case in which all requests have equal priorities and all resoruces have equal precedences, and the comparisons between our APS and other schems are discussed in the paper. The APS provides the heuristic rules which are based on maximum height (MH), number of children nodes ($N_c$), number of father nodes ($N_f$), and computation time ($T_c$). The estimation moth of the computaion time is in the paper.

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아파트 단위주거 평면의 규모별 공간구성에 관한 기초 연구 (An Analysis of the Unit Plan Characteristics for the Apartments at Metropolitan Seoul Area in the Context of Space Syntax Model)

  • 이동원;오도엽
    • 한국실내디자인학회논문집
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    • 제13권1호
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    • pp.81-88
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    • 2004
  • The purpose of this study is to analyze spatial configuration of the unit floor plan characteristics of the apartments built in Seoul Metropolitan area by using the Space Syntax methodology and finally to test the relationship between space in the unit floor plans. So the unit floor plans are analyzed using sector graphs from justified graph and computer programs based on the Space Syntax model and compared by size. The results are as follows; The sector graphs are summarized in 14 types. The total depth of spaces is not in proportion to the plan area. And the global and local integration and intelligibility are inversely proportional to the area. But in the case of largest areas(265$m^2$ and above), the integration and intelligibility increase.

열 생성 기법을 이용한 스타이너 나무 분할 문제에 관한 연구 (Column Generation Approach to the Steiner Tree Packing Problem)

  • 정규웅;이경식;박성수;박경철
    • 한국경영과학회지
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    • 제25권3호
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    • pp.17-33
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    • 2000
  • We consider the Steiner tree packing problem. For a given undirected graph G =(V, E) with positive integer capacities and non-negative weights on its edges, and a list of node sets(nets), the problem is to find a connection of nets which satisfies the edge capacity limits and minimizes the total weights. We focus on the switchbox routing problem in knock-knee model and formulate this problem as an integer programming using Steiner tree variables. The model contains exponential number of variables, but the problem can be solved using a polynomial time column generation procedure. We test the algorithm on some standard test instances and compare the performances with the results using cutting plane approach. Computational results show that our algorithm is competitive to the cutting plane algorithm presented by Grotschel et al. and can be used to solve practically sized problems.

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여러 개의 목적함수와 운행시간제약을 가진 버스일정계획 (A Bus Scheduling Problem with Multiple Objective Functions and Travel Time Constraint)

  • 김우제
    • 산업공학
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    • 제15권1호
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    • pp.49-54
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    • 2002
  • A bus scheduling problem with multiple objective functions and travel time constraint is to determine the allocation of buses to customer service requests minimizing the number of buses and travel costs under the travel time restriction for each bus. For the scheduling, we first represent the scheduling problem using a graph and develop a hierarchical approach. Second, we develop a mathematical model based algorithm for the scheduling problem including heuristic methods. We tested the performance of the algorithm on instances with real data. As a result, the total number of buses and travel costs are reduced over about 10% comparing with that of current practice at the company.

Development of a Stand Density Management Diagram for Teak Forests in Southern India

  • Tewari, Vindhya Prasad;Alvarez-Gonz, Juan Gabriel
    • Journal of Forest and Environmental Science
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    • 제30권3호
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    • pp.259-266
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    • 2014
  • Stand Density Diagrams (SDD) are average stand-level models which graphically illustrate the relationship between yield, density and mortality throughout the various stages of forest development. These are useful tools for designing, displaying and evaluating alternative density regimes in even-aged forest ecosystems to achieve a desired future condition. This contribution presents an example of a SDD that has been constructed for teak forests of Karnataka in southern India. The relationship between stand density, dominant height, quadratic mean diameter, relative spacing and stand volume is represented in one graph. The relative spacing index was used to characterize the population density. Two equations were fitted simultaneously to the data collected from 27 sample plots measured annually for three years: one relates quadratic mean diameter with stand density and dominant height while the other relates total stand volume with quadratic mean diameter, stand density and dominant height.

선회화염 의 구조 에 따른 NO , CO 및 THC 생성특성 에 관한 연구 (A Study on the Formation Characteristics of NO, CO and THC with respect to the Structure of the Swirl Flame)

  • 윤재건;명현국;신현동
    • 대한기계학회논문집
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    • 제8권3호
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    • pp.210-216
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    • 1984
  • 본 연구에서는 이러한 화염의 구조를 자세히 파악하기 위하여, 화염의 온도분 포 및 가스농도분포 등을 비교적 정밀하게 측정하고 Shadow graph 등을 통하여, 선회 화염의 거시적인 구조적 특성을 알아보고 일산화질소, 탄화수소 및 일산화탄소 등의 생성특성을 규명함으로서 실제 버어너에서의 기하학적 변형에 따른 화염구조의 예측과 수치해석을 위한 기본 데이타를 얻고, 공해물질발생과 화염구조와의 상관관계를 제시 하는데 그 목적이 있다.

개미군 최적화 방법을 적용한 무선 센서 네트워크에서의 클러스터링 최적 설계 (Clustering Optimal Design in Wireless Sensor Network using Ant Colony Optimization)

  • 김성수;최승현
    • 경영과학
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    • 제26권3호
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    • pp.55-65
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    • 2009
  • The objective of this paper is to propose an ant colony optimization (ACO) for clustering design in wireless sensor network problem. This proposed ACO approach is designed to deal with the dynamics of the sensor nodes which can be adaptable to topological changes to any network graph in a time. Long communication distances between sensors and a sink in a sensor network can greatly consume the energy of sensors and reduce the lifetime of a network. We can greatly minimize the total communication distance while minimizing the number of cluster heads using proposed ACO. Simulation results show that our proposed method is very efficient to find the best solutions comparing to the optimal solution using CPLEX in 100, 200, and 400 node sensor networks.