• 제목/요약/키워드: Problem finding

검색결과 1,670건 처리시간 0.026초

Development of evolutionary algorithm for determining the k most vital arcs in shortest path problem

  • Chung, Hoyeon;Shin, Dongju
    • 한국경영과학회:학술대회논문집
    • /
    • 한국경영과학회 2000년도 추계학술대회 및 정기총회
    • /
    • pp.113-116
    • /
    • 2000
  • The purpose of this study is to present a method for determining the k most vital arcs in shortest path problem using an evolutionary algorithm. The problem of finding the k most vital arcs in shortest path problem is to find a set of k arcs whose simultaneous removal from the network causes the greatest increase in the total length of shortest path. The problem determining the k most vital arcs in shortest path problem has known as NP-hard. Therefore, in order to deal with the problem of real world the heuristic algorithm is needed. In this study we propose to the method of finding the k-MVA in shortest path problem using an evolutionary algorithm which known as the most efficient algorithm among heuristics. For this, the expression method of individuals compatible with the characteristics of shortest path problem, the parameter values of constitution gene, size of the initial population, crossover rate and mutation rate etc. are specified and then the effective genetic algorithm will be proposed. The method presented in this study is developed using the library of the evolutionary algorithm framework (EAF) and then the performance of algorithm is analyzed through the computer experiment.

  • PDF

Optimization of the Travelling Salesman Problem Using a New Hybrid Genetic Algorithm

  • Zakir Hussain Ahmed;Furat Fahad Altukhaim;Abdul Khader Jilani Saudagar;Shakir Khan
    • International Journal of Computer Science & Network Security
    • /
    • 제24권3호
    • /
    • pp.12-22
    • /
    • 2024
  • The travelling salesman problem is very famous and very difficult combinatorial optimization problem that has several applications in operations research, computer science and industrial engineering. As the problem is difficult, finding its optimal solution is computationally very difficult. Thus, several researchers have developed heuristic/metaheuristic algorithms for finding heuristic solutions to the problem instances. In this present study, a new hybrid genetic algorithm (HGA) is suggested to find heuristic solution to the problem. In our HGA we used comprehensive sequential constructive crossover, adaptive mutation, 2-opt search and a new local search algorithm along with a replacement method, then executed our HGA on some standard TSPLIB problem instances, and finally, we compared our HGA with simple genetic algorithm and an existing state-of-the-art method. The experimental studies show the effectiveness of our proposed HGA for the problem.

A Review of Dose Finding Methods and Theory

  • Cheung, Ying Kuen
    • Communications for Statistical Applications and Methods
    • /
    • 제22권5호
    • /
    • pp.401-413
    • /
    • 2015
  • In this article, we review the statistical methods and theory for dose finding in early phase clinical trials, where the primary objective is to identify an acceptable dose for further clinical investigation. The dose finding literature is initially motivated by applications in phase I clinical trials, in which dose finding is often formulated as a percentile estimation problem. We will present some important phase I methods and give an update on new theoretical developments since a recent review by Cheung (2010), with an aim to cover a broader class of dose finding problems and to illustrate how the general dose finding theory may be applied to evaluate and improve a method. Specifically, we will illustrate theoretical techniques with some numerical results in the context of a phase I/II study that uses trinary toxicity/efficacy outcomes as basis of dose finding.

케이블돔 구조물의 안정화 이행과정 및 구조적 거동특성에 관한 연구 (A Study on the Stabilizing Process and Structural Characteristics of Cable-Dome Structure)

  • 한상을;이경수;이주선;황보석
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 1999년도 봄 학술발표회 논문집
    • /
    • pp.260-267
    • /
    • 1999
  • In this paper, We propose the initial shape finding and dynamic analysis of cable dome structure are presented. Cable dome that is consist of three component such as cable, strut and fabric membrane have complex structural characteristics. Main structural system of cable dome is cable-strut tensegric system, and fabric membrane element Is conceived as cladding roof material. One of the important problem of cable dome is shape finding of those subjected to cable and membrane forces, which stabilize the structures. And the other is structural response from external load effect such as snow and wind When cable dome are subjected to dynamic load such as wind load each structural component has many important problem because of their special structural characteristics. One problem is that geometrical nonlinearity should be considered in the dynamic analysis because large deformation is occurred from their flexible characteristic. The other problem is that wrinkling occurs occasionally because cable and membrane elements can not transmit compressive forces. So this paper describe the physical structural response of cable dome structure.

  • PDF

A Repeated Mapping Scheme of Task Modules with Minimum Communication Cost in Hypercube Multicomputers

  • Kim, Joo-Man;Lee, Cheol-Hoon
    • ETRI Journal
    • /
    • 제20권4호
    • /
    • pp.327-345
    • /
    • 1998
  • This paper deals with the problem of one-to-one mapping of 2$^n$ task modules of a parallel program to an n-dimensional hypercube multicomputer so as to minimize the total communication cost during the execution of the task. The problem of finding an optimal mapping has been proven to be NP-complete. First we show that the mapping problem in a hypercube multicomputer can be transformed into the problem of finding a set of maximum cutsets on a given task graph using a graph modification technique. Then we propose a repeated mapping scheme, using an existing graph bipartitioning algorithm, for the effective mapping of task modules onto the processors of a hypercube multicomputer. The repeated mapping scheme is shown to be highly effective on a number of test task graphs; it increasingly outperforms the greedy and recursive mapping algorithms as the number of processors increases. Our repeated mapping scheme is shown to be very effective for regular graphs, such as hypercube-isomorphic or 'almost' isomorphic graphs and meshes; it finds optimal mappings on almost all the regular task graphs considered.

  • PDF

서비스시간 제한이 있는 복합교통망에서의 경로안내 시스템을 위한 유전자 알고리듬 (A Genetic Algorithm for Route Guidance System in Intermodal Transportation Networks with Time - Schedule Constraints)

  • 장인성
    • 대한산업공학회지
    • /
    • 제27권2호
    • /
    • pp.140-149
    • /
    • 2001
  • The paper discusses the problem of finding the Origin-Destination(O-D) shortest paths in internodal transportation networks with time-schedule constraints. The shortest path problem on the internodal transportation network is concerned with finding a path with minimum distance, time, or cost from an origin to a destination using all possible transportation modalities. The time-schedule constraint requires that the departure time to travel from a transfer station to another node takes place only at one of pre-specified departure times. The scheduled departure times at the transfer station are the times when the passengers are allowed to leave the station to another node using the relative transportation modality. Therefore, the total time of a path in an internodal transportation network subject to time-schedule constraints includes traveling time and transfer waiting time. In this paper, a genetic algorithm (GA) approach is developed to deal with this problem. The effectiveness of the GA approach is evaluated using several test problems.

  • PDF

과학 영재 학생들의 과학적 문제발견 능력을 측정하기 위한 도구 개발 (Development of an Instrument to Measure Scientific Problem-Finding Ability for Scientifically-Gifted Student)

  • 류시경;박종석
    • 한국과학교육학회지
    • /
    • 제28권2호
    • /
    • pp.139-149
    • /
    • 2008
  • 본 연구에서는 과학 영재 학생들의 과학적 문제발견 능력을 측정하기 위해 타당도와 신뢰도가 높은 검사 도구를 개발하였다. 먼저, 과학적 문제발견 능력에 대한 조작적 정의를 바탕으로 5개의 하위 평가 요소(적절성, 융통성, 독창성, 정교성, 가치 판단)를 선정하였으며 평가 기준을 구안하였다. 개발된 검사 도구는 내용 및 평가 기준에 대해 과학교육 전문가의 타당도 검증을 거친 후 과학 고등학교 학생들에게 투입되었으며, 채점 결과를 바탕으로 구인 타당도를 검증받았다. 또한 채점자간 신뢰도는 대체로 높게 나타났으며, 문항 난이도 와 변별도 역시 적절한 것으로 나타났다. 앞으로 과학적 문제발견 능력에 대한 합의된 정의를 도출해내어야 하며 평가의 객관성을 확보하기 위한 더 나은 방안을 강구해야 한다.

STRONG CONVERGENCE THEOREMS FOR ASYMPTOTICALLY QUASI-NONEXPANSIVE MAPPINGS AND INVERSE-STRONGLY MONOTONE MAPPINGS

  • He, Xin-Feng;Xu, Yong-Chun;He, Zhen
    • East Asian mathematical journal
    • /
    • 제27권1호
    • /
    • pp.1-9
    • /
    • 2011
  • In this paper, we consider an iterative scheme for finding a common element of the set of fixed points of a asymptotically quasi nonexpansive mapping and the set of solutions of the variational inequality for an inverse strongly monotone mapping in a Hilbert space. Then we show that the sequence converges strongly to a common element of two sets. Using this result, we consider the problem of finding a common fixed point of a asymptotically quasi-nonexpansive mapping and strictly pseudocontractive mapping and the problem of finding a common element of the set of fixed points of a asymptotically quasi-nonexpansive mapping and the set of zeros of an inverse-strongly monotone mapping.

Stack Bin Packing Algorithm for Containers Pre-Marshalling Problem

  • Lee, Sang-Un
    • 한국컴퓨터정보학회논문지
    • /
    • 제20권10호
    • /
    • pp.61-68
    • /
    • 2015
  • This paper deals with the pre-marshalling problem that the containers of container yard at container terminal are relocated in consensus sequence of loading schedule of container vessel. This problem is essential to improvement of competitive power of terminal. This problem has to relocate the all of containers in a bay with minimum number of movement. There are various algorithms such as metaheuristic as genetic algorithm and heuristic algorithm in order to find the solution of this problem. Nevertheless, there is no unique general algorithm that is suitable for various many data. And the main drawback of metaheuristic methods are not the solution finding rule but can be find the approximated solution with many random trials and by coincidence. This paper can be obtain the solution with O(m) time complexity that this problem deals with bin packing problem for m stack bins with descending order of take out ranking. For various experimental data, the proposed algorithm can be obtain the optimal solutions for all of data. And to conclude, this algorithm can be show that most simple and general algorithm with simple optimal solution finding rule.