• 제목/요약/키워드: computational algorithm

검색결과 4,384건 처리시간 0.03초

열원을 이용한 공정에서 지그재그 공구 경로 연결 알고리즘 (Zigzag Tool-Path Linking Algorithm for Shaping Process Using Heat Source)

  • 김효찬;이상호;양동열
    • 한국CDE학회논문집
    • /
    • 제9권4호
    • /
    • pp.286-293
    • /
    • 2004
  • Recently, hot processing using the heat source like laser machining and RFS was developed and spreaded gradually. In order to generate tool-path for the proper hot tool, a new tool-path linking algorithm is needed because tool-path linking algorithm for machining can't be applied. In this paper, zigzag tool-path liking algorithm was proposed to generate tool-path automatically for RFS. The algorithm is composed of three steps: 1) Generating valid tool-path element, 2) Storing tool-path elements and creating sub-groups, 3) linking sub-groups. Using the proposed algorithm, CAD/CAM software for the tool-path generation of hot tool was developed. The proposed algorithm was applied and verified for Venus's face and die of cellular phone case.

터부 알고리즘에 의한 대공간 구조물의 최적설계 (The Optimum Design of Spatial Structures by TABU Algorithm)

  • 한상을;이상주;조용원;김민식
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2004년도 가을 학술발표회 논문집
    • /
    • pp.171-178
    • /
    • 2004
  • The purpose of optimum design for structures is to minimize the cost and to obtain the reasonable structural systems. This design algorithm have many objective functions including discrete variables as sections, weight, stiffness and shapes. Simulated annealing, Genetic algorithm and TABU algorithm are used search for these optimum values in the structural design. TABU algorithm is applied to many types structures to search for section and distribution optimization and compared with the results of Genetic algorithm for evaluating the efficiency of this algorithm. In this paper, the plane truss of 10 elements and the space truss of 25 element having 10 nodes, star dome and cable dome are analyzed as analytical models.

  • PDF

전역 최적화를 위한 B-스플라인 기반의 Branch & Bound알고리즘 (A B-spline based Branch & Bound Algorithm for Global Optimization)

  • 박상근
    • 한국CDE학회논문집
    • /
    • 제15권1호
    • /
    • pp.24-32
    • /
    • 2010
  • This paper introduces a B-spline based branch & bound algorithm for global optimization. The branch & bound is a well-known algorithm paradigm for global optimization, of which key components are the subdivision scheme and the bound calculation scheme. For this, we consider the B-spline hypervolume to approximate an objective function defined in a design space. This model enables us to subdivide the design space, and to compute the upper & lower bound of each subspace where the bound calculation is based on the LHS sampling points. We also describe a search tree to represent the searching process for optimal solution, and explain iteration steps and some conditions necessary to carry out the algorithm. Finally, the performance of the proposed algorithm is examined on some test problems which would cover most difficulties faced in global optimization area. It shows that the proposed algorithm is complete algorithm not using heuristics, provides an approximate global solution within prescribed tolerances, and has the good possibility for large scale NP-hard optimization.

Munkres 최적할당 기법을 적용한 무기할당 알고리즘 (A Weapon Assignment Algorithm Using the Munkres Optimal Assignment Method)

  • 김지은;신진화;조길석
    • 한국군사과학기술학회지
    • /
    • 제13권1호
    • /
    • pp.1-8
    • /
    • 2010
  • This paper presents global and optimal solution for weapon assignment problems using the Munkres assignment algorithm. We propose a new modeling method of weapon assignment problems concerning some constraints of weapon systems. In this paper, we compares the Munkres weapon assignment algorithm with two other algorithms employing a search tree model in terms of computational complexity and performance. One is an optimal algorithm using exhausted search and the other is a greedy algorithm which selects the first search result as a solution. The experiment results show that the Munkres weapon assignment algorithm has better performance and less computational complexity in comparison with the two other algorithms.

이산형 변수를 이용한 뼈대구조물의 다단계 최적설계 (Multi-Level Optimization for Steel Frames using Discrete Variables)

  • 조효남;민대용;박준용
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2000년도 가을 학술발표회논문집
    • /
    • pp.115-124
    • /
    • 2000
  • An efficient multi-level (EML) optimization algorithm using discrete variables of framed structures is proposed in this paper. For the efficiency of the proposed algorithm multi-level optimization techniques using a decomposition method that separates both system-level and element-level are incorporated in the algorithm In the system-level, to save the numerical efforts an efficient reanalysis technique through approximated structural responses such as moments and frequencies with respect to intermediate variables is proposed in the paper. Sensitivity analysis of dynamic structural response is executed by automatic differentiation (AD) that is a powerful technique for computing complex or implicit derivatives accurately and efficiently with minimal human effort. In the element-level, to use AISC W-sections a section search algorithm is introduced. The efficiency and robustness of the EML algorithm, compared with a conventional multi-level (CML) algorithm and single-level genetic algorithm is successfully demonstrated in the numerical examples.

  • PDF

Parameter estimation of weak space-based ADS-B signals using genetic algorithm

  • Tao, Feng;Jun, Liang
    • ETRI Journal
    • /
    • 제43권2호
    • /
    • pp.324-331
    • /
    • 2021
  • Space-based automatic dependent surveillance-broadcast (ADS-B) is an important emerging augmentation of existing ground-based ADS-B systems. In this paper, the problem of space-based ultra-long-range reception processing of ADS-B signals is described. We first introduce a header detection method for accurately determining the pulse position of a weak ADS-B signal. We designed a signal encoding method, shaping method, and fitness function. We then employed a genetic algorithm to perform high-precision frequency and phase estimations of the detected weak signal. The advantage of this algorithm is that it can simultaneously estimate the frequency and phase, meaning a direct coherent demodulation can be implemented. To address the computational complexity of the genetic algorithm, we improved the ratio algorithm for frequency estimation and raised the accuracy beyond that of the original ratio algorithm with only a slight increase in the computational complexity using relatively few sampling points.