• Title/Summary/Keyword: step problem

Search Result 1,875, Processing Time 0.027 seconds

A Study on the Systematic, Intuitive Approach for Fashion Design (패션 디자인을 위한 체계적, 직관적 접근방법에 관한 고찰)

  • 최윤미
    • The Research Journal of the Costume Culture
    • /
    • v.5 no.1
    • /
    • pp.71-83
    • /
    • 1997
  • It is the important situation that the fashion industry is faced to enormous changes in the nation and worldwide market. To cope with this situations, it is necessary to clarify that the concept of fashion design and its process. This study was conducted as followings : 1. Fashion design is the process of problem solving including the steps of understanding problem, visualizing the image of a design concept. 2. The systematic and intuitive approach is harmonized to solve the process of fashion design. 3. The step of understanding problem is consist of the analysis of environments, the explanation of problem, the determination of purposes, the definition of problem and the visualizing the image of a design concept. 4. In the step of the visualizing the image of a design concept, the intuitive approaches can be clarifies as the importance of start, the step by step process, the determination of a design concept, the fixations of an image, the image realization through real objects, the diminution a difference between a concept and a visualizing the image and the necessity of exercises.

  • PDF

Integrated Vehicle Routing Model for Multi-Supply Centers Based on Genetic Algorithm (유전자알고리즘 및 발견적 방법을 이용한 차량운송경로계획 모델)

  • 황흥석
    • Journal of the Korea Society for Simulation
    • /
    • v.9 no.3
    • /
    • pp.91-102
    • /
    • 2000
  • The distribution routing problem is one of the important problems in distribution and supply center management. This research is concerned with an integrated distribution routing problem for multi-supply centers based on improved genetic algorithm and GUI-type programming. In this research, we used a three-step approach; in step 1 a sector clustering model is developed to transfer the multi-supply center problem to single supply center problems which are more easy to be solved, in step 2 we developed a vehicle routing model with time and vehicle capacity constraints and in step 3, we developed a GA-TSP model which can improve the vehicle routing schedules by simulation. For the computational purpose, we developed a GUI-type computer program according to the proposed methods and the sample outputs show that the proposed method is very effective on a set of standard test problems, and it could be potentially useful in solving the distribution routing problems in multi-supply center problem.

  • PDF

Single Machine Scheduling Problem with Step-deterioration under A Rate-modifying Activity (단일 복구조정활동 하에 단계적 퇴화를 가지는 단일기계 생산일정계획)

  • Kim, Byung Soo
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.37 no.3
    • /
    • pp.43-50
    • /
    • 2014
  • In this paper, we deal with a single machine scheduling problems integrating with step deterioration effect and a rate-modifying activity (RMA). The scheduling problem assumes that the machine may have a single RMA and each job has the processing time of a job with deterioration is a step function of the gap between recent RMA and starting time of the job and a deteriorating date that is individual to all jobs. Based on the two scheduling phenomena, we simultaneously determine the schedule of step deteriorating jobs and the position of the RMA to minimize the makespan. To solve the problem, we propose a hybrid typed genetic algorithm compared with conventional GAs.

A Max-Min Ant Colony Optimization for Undirected Steiner Tree Problem in Graphs (스타이너 트리 문제를 위한 Mar-Min Ant Colony Optimization)

  • Seo, Min-Seok;Kim, Dae-Cheol
    • Korean Management Science Review
    • /
    • v.26 no.1
    • /
    • pp.65-76
    • /
    • 2009
  • The undirected Steiner tree problem in graphs is known to be NP-hard. The objective of this problem is to find a shortest tree containing a subset of nodes, called terminal nodes. This paper proposes a method based on a two-step procedure to solve this problem efficiently. In the first step. graph reduction rules eliminate useless nodes and edges which do not contribute to make an optimal solution. In the second step, a max-min ant colony optimization combined with Prim's algorithm is developed to solve the reduced problem. The proposed algorithm is tested in the sets of standard test problems. The results show that the algorithm efficiently presents very correct solutions to the benchmark problems.

STABILITY AND ERROR OF THE VARIABLE TWO-STEP BDF FOR SEMILINEAR PARABOLIC PROBLEMS

  • EMMRICH ETIENNE
    • Journal of applied mathematics & informatics
    • /
    • v.19 no.1_2
    • /
    • pp.33-55
    • /
    • 2005
  • The temporal discretisation of a moderate semilinear parabolic problem in an abstract setting by the two-step backward differentiation formula with variable step sizes is analysed. Stability as well as optimal smooth data error estimates are derived if the ratios of adjacent step sizes are bounded from above by 1.91.

An Ant Colony Optimization Algorithm to Solve Steiner Tree Problem (스타이너 트리 문제를 위한 Ant Colony Optimization 알고리즘의 개발)

  • Seo, Min-Seok;Kim, Dae-Cheol
    • Journal of the Korean Operations Research and Management Science Society
    • /
    • v.33 no.3
    • /
    • pp.17-28
    • /
    • 2008
  • The Steiner arborescence problem is known to be NP-hard. The objective of this problem is to find a minimal Steiner tree which starts from a designated node and spans all given terminal nodes. This paper proposes a method based on a two-step procedure to solve this problem efficiently. In the first step, graph reduction rules eliminate useless nodes and arcs which do not contribute to make an optimal solution. In the second step. ant colony algorithm with use of Prim's algorithm is used to solve the Steiner arborescence problem in the reduced graph. The proposed method based on a two-step procedure is tested in the five test problems. The results show that this method finds the optimal solutions to the tested problems within 50 seconds. The algorithm can be applied to undirected Steiner tree problems with minor changes. 18 problems taken from Beasley are used to compare the performances of the proposed algorithm and Singh et al.'s algorithm. The results show that the proposed algorithm generates better solutions than the algorithm compared.

Error Estimation and Adaptive Time Stepping Procedure for Structural Dynamics (구조동역학에서의 오차 추정과 시간간격 제어 알고리즘)

  • 장인식
    • Transactions of the Korean Society of Automotive Engineers
    • /
    • v.4 no.4
    • /
    • pp.190-200
    • /
    • 1996
  • Step-by-step time integration methods are widely used for solving structural dynamics problem. One difficult yet critical choice an analyst must make is to decide an appropriate time step size. The choice of time step size has a significant effect on solution accuracy and computational expense. The objective of this research is to derive error estimate for newly developed time integration method and develop automatic time step size control algorithm for structural dynamics. A formula for computing error tolerance is derived based on desired period resolution. An automatic time step size control strategy is proposed based on a normalized local error estimate for the generalized-α method. Numerical examples demonstrate the developed strategy satisfies general design criteria for time step size control algorithm for dynamic problem.

  • PDF

Cognitive Components Definition of Creative Problem-Solving Ability in Informatics Education (정보 교육에서 요구되는 창의적 문제해결능력의 인지적 요소 정의)

  • Kim, JongHye;Jeong, HoiGang;Kim, HanSung;Kim, HyeonCheol;Lee, WonGyu
    • The Journal of Korean Association of Computer Education
    • /
    • v.11 no.2
    • /
    • pp.1-12
    • /
    • 2008
  • It is important to improve the creative problem- solving ability through subject matter education. Especially, Informatics education is important to improve the problem-solving ability by using computer as well as the general problem-solving ability. This paper identifies the creative problem- solving ability which is required in Informatics education. The cognitive components of the creative problem-solving ability are organized as the result of crossing the problem-solving ability and the creativity. This paper investigated the validity of the contents as judged by a panel of experts. The cognitive components of creativity are the elaboration, sensitivity, and reorganization in the step of 'Understanding and Analysis the Problem'. Also, The cognitive components of creativity are the fluency, flexibility, and originality in the step of the 'Exploring the Problem Solutions'. The cognitive components of creativity are elaboration in the step of the 'Design the Problem Solution' and 'Implementation'. Finally, the cognitive components of creativity are the flexibility and elaboration in the step of the 'Evaluation'.

  • PDF

A Design of an Active Noise Controller in a Communication Headset (통신용 헤드셋에서 능동소음제어기의 설계)

  • 정태진;정찬수
    • 제어로봇시스템학회:학술대회논문집
    • /
    • 1997.10a
    • /
    • pp.81-84
    • /
    • 1997
  • This paper studies an active noise controller in a communication headset. The system is a two inputs(communication signal and noise signal) and single output(error signal) system. The problem is to reduce noise level sufficiently lower than communication signal to receive the communication signal clearly. The approach to this problem is in two steps. In the first step, we solve the noise rejection problem without communication signals. In this step, the problem is transformed to the robust H$_{\infty}$ regulating problem and solved using Linear Matrix Inequalities. In the second step, communication signal is introduced to the system, To verify the performance of the designed controller, a couple of experiments are performed..

  • PDF

PRECONDITIONERS FOR THE PRESSURE-CORRECTION METHOD APPLIED TO THE UNSTEADY STOKES PROBLEM

  • Ghahreman, N.;Kerayechian, A.
    • Journal of applied mathematics & informatics
    • /
    • v.16 no.1_2
    • /
    • pp.307-321
    • /
    • 2004
  • In this paper, the unsteady Stokes problem is considered and also the pressure-correction method for the problem is described. At a fixed time level, we reduce the problem to two symmetric positive definite problems which depend on a time step parameter. Linear systems that arise from the problems are large, sparse, symmetric, positive definite and ill-conditioned as the time step tends to zero. Preconditioned problems based on an additive Schwarz method for solving the symmetric positive definite problems are derived and preconditioners are defined implicitly. It will be shown that the rate of convergence is independent of the mesh parameters as well as the time step size.