• Title/Summary/Keyword: Spatial optimization problem

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Comparison of Spatial Optimization Techniques for Solving Visibility Location Problem (가시권 문제를 위한 공간최적화 기법 비교 연구)

  • Kim, Young-Hoon
    • Journal of the Korean Association of Geographic Information Studies
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    • v.9 no.3
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    • pp.156-170
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    • 2006
  • Determining the best visibility positions on terrain surface has been one of the frequently used analytical issues in GIS visibility analysis and the search for a solution has been carried out effectively using spatial search techniques. However, the spatial search process provides operational and methodological challenges for finding computational algorithms suitable for solving the best visibility site problem. For this problem, current GIS visibility analysis has not been successful due to limited algorithmic structure and operational performance. To meet these challenges, this paper suggests four algorithms explored robust search techniques: an extensive iterative search technique; a conventional solution based on the Tornqvist algorithm; genetic algorithm; and simulated annealing technique. The solution performance of these algorithms is compared on a set of visibility location problems and the experiment results demonstrate the useful feasibility. Finally, this paper presents the potential applicability of the new spatial search techniques for GIS visibility analysis by which the new search algorithms are of particular useful for tackling extensive visibility optimization problems as the next GIS analysis tool.

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Duality in an Optimal Harvesting Problem by a Nonlinear Age-Spatial Structured Population Dynamic System

  • Kim, Yong-Kuk;Lee, Mi-Jin;Jung, Il-Hyo
    • Kyungpook Mathematical Journal
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    • v.51 no.4
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    • pp.353-364
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    • 2011
  • Duality in the optimal harvesting for a nonlinear age-spatial structured population dynamic model is studied in the framework of optimal control problem. In this paper the duality theory that displays the conjugacy of the primal problem is established and an application is given. Duality theory plays an important role in both optimization theory and methodology and the results may be applied to a realistic biological system on the point of optimal harvesting.

Interface Technique for Optimization of Free-form Structural System (구조 최적화를 위한 비정형 구조시스템의 인터페이스 기법)

  • Na, Yoo-Mi;Lee, Jae-Hong;Kang, Joo-Won
    • Journal of Korean Association for Spatial Structures
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    • v.12 no.1
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    • pp.43-50
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    • 2012
  • Recently, due to the advanced computer technology, momental architectures have been designed and built using features that are very sophisticated. People's interest in free-form structural system has increased steadily not only nationwide, but also worldwide. However, there were many difficulties in the materialization of free-form structural system owing to the lack of technique and research. To solve this problem, this study performs the interface between the 3D modeling program and the optimization program. In the 3D modeling program, it is possible to automatic mesh generation and immediately to information extraction. It performs the shape optimization. Consequently, this research designs the example model and performs optimization in order to verify the developed interface module.

Inverse Kinematics of Complex Chain Robotic Mechanism Using Ralative Coordinates (상대좌표를 이용한 복합연쇄 로봇기구의 역기구학)

  • Kim, Chang-Bu;Kim, Hyo-Sik
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.20 no.11
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    • pp.3398-3407
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    • 1996
  • In this paper, we derive an algorithm and develope a computer program which analyze rapidly and precisely the inverse kinematics of robotic mechanism with spatial complex chain structure based on the relative coordinates. We represent the inverse kinematic problem as an optimization problem with the kinematic constraint equations. The inverse kinematic analysis algorithm, therefore, consists of two algorithms, the main, an optimization algorithm finding the motion of independent joints from that of an end-effector and the sub, a forward kinematic analysis algorithm computing the motion of dependent joints. We accomplish simulations for the investigation upon the accuracy and efficiency of the algorithm.

Shape and size optimization of trusses with dynamic constraints using a metaheuristic algorithm

  • Grzywinski, Maksym;Selejdak, Jacek;Dede, Tayfun
    • Steel and Composite Structures
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    • v.33 no.5
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    • pp.747-753
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    • 2019
  • Metaheuristic algorithm is used to solve the weight minimization problem of truss structures considering shape, and sizing design variables. The cross-sectional areas of the line element in trusses are the design variables for size optimization and the changeable joint coordinates are the shape optimization used in this study. The design of plane and spatial truss structures are optimized by metaheuristic technique named Teaching-Learning-Based Optimization (TLBO). Finite element analyses of structures and optimization process are carried out by the computer program visually developed by the authors coded in MATLAB. The four benchmark problems (trusses 2D ten-bar, 3D thirty-seven-bar, 3D seventy-two-bar and 2D two-hundred-bar) taken from literature are optimized and the optimal solution compared the results given by previous studies.

Zoning Permanent Basic Farmland Based on Artificial Immune System coupling with spatial constraints

  • Hua, Wang;Mengyu, Wang;Yuxin, Zhu;Jiqiang, Niu;Xueye, Chen;Yang, Zhang
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.15 no.5
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    • pp.1666-1689
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    • 2021
  • The red line of Permanent Basic Farmland is the most important part in the "three-line" demarcation of China's national territorial development plan. The scientific and reasonable delineation of the red line is a major strategic measure being taken by China to improve its ability to safeguard the practical interests of farmers and guarantee national food security. The delineation of Permanent Basic Farmland zoning (DPBFZ) is essentially a multi-objective optimization problem. However, the traditional method of demarcation does not take into account the synergistic development goals of conservation of cultivated land utilization, ecological conservation, or urban expansion. Therefore, this research introduces the idea of artificial immune optimization and proposes a multi-objective model of DPBFZ red line delineation based on a clone selection algorithm. This research proposes an objective functional system consisting of these three sub-objectives: optimal quality of cropland, spatially concentrated distribution, and stability of cropland. It also takes into consideration constraints such as the red line of ecological protection, topography, and space for major development projects. The mathematical formal expressions for the objectives and constraints are given in the paper, and a multi-objective optimal decision model with multiple constraints for the DPBFZ problem is constructed based on the clone selection algorithm. An antibody coding scheme was designed according to the spatial pattern of DPBFZ zoning. In addition, the antibody-antigen affinity function, the clone mechanism, and mutation strategy were constructed and improved to solve the DPBFZ problem with a spatial optimization feature. Finally, Tongxu County in Henan province was selected as the study area, and a controlled experiment was set up according to different target preferences. The results show that the model proposed in this paper is operational in the work of delineating DPBFZ. It not only avoids the adverse effects of subjective factors in the delineation process but also provides multiple scenarios DPBFZ layouts for decision makers by adjusting the weighting of the objective function.

Optimal EEG Channel Selection using BPSO with Channel Impact Factor (Channel Impact Factor 접목한 BPSO 기반 최적의 EEG 채널 선택 기법)

  • Kim, Jun-Yeup;Park, Seung-Min;Ko, Kwang-Eun;Sim, Kwee-Bo
    • Journal of the Korean Institute of Intelligent Systems
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    • v.22 no.6
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    • pp.774-779
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    • 2012
  • Brain-computer interface based on motor imagery is a system that transforms a subject's intention into a control signal by classifying EEG signals obtained from the imagination of movement of a subject's limbs. For the new paradigm, we do not know which positions are activated or not. A simple approach is to use as many channels as possible. The problem is that using many channels causes other problems. When applying a common spatial pattern (CSP), which is an EEG extraction method, many channels cause an overfit problem, in addition there is difficulty using this technique for medical analysis. To overcome these problems, we suggest a binary particle swarm optimization with channel impact factor in order to select channels close to the most important channels as channel selection method. This paper examines whether or not channel impact factor can improve accuracy by Support Vector Machine(SVM).

Suggestion for Spatialization of Environmental Planning Using Spatial Optimization Model (공간최적화 모델을 활용한 환경계획의 공간화 방안)

  • Yoon, Eun-Joo;Lee, Dong-Kun;Heo, Han-Kyul;Sung, Hyun-Chan
    • Journal of the Korean Society of Environmental Restoration Technology
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    • v.21 no.2
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    • pp.27-38
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    • 2018
  • Environmental planning includes resource allocation and spatial planning process for the conservation and management of environment. Because the spatialization of the environmental planning is not specifically addressed in the relevant statutes, it actually depends on the qualitative methodology such as expert judgement. The results of the qualitative methodology have the advantage that the accumulated knowledge and intuition of the experts can be utilized. However, it is difficult to objectively judge whether it is enough to solve the original problem or whether it is the best of the possible scenarios. Therefore, this study proposed a methodology to quantitatively and objectively spatialize various environmental planning. At first, we suggested a quantitative spatial planning model based on an optimization algorithm. Secondly, we applied this model to two kinds of environmental planning and discussed about the model performance to present the applicability. Since the models were developed based on conceptual study site, there was a limitation in showing possibility of practical use. However, we expected that this study can contribute to the fields related to environmental planning by suggesting flexible and novel methodology.

Multi-objective Optimization for Force Design of Tensegrity Structures (텐세그리티 구조물 설계를 위한 다목적 최적화 기법에 관한 연구)

  • Ohsaki, Makoto;Zhang, Jingyao;Kim, Jae-Yeol
    • Journal of Korean Association for Spatial Structures
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    • v.8 no.1
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    • pp.49-56
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    • 2008
  • A multi-objective optimization approach is presented for force design of tensegrity structures. The geometry of the structure is given a priori. The design variables are the member forces, and the objective functions are the lowest eigenvalue of the tangent stiffness matrix that is to be maximized, and the deviation of the member forces from the target values that is to be minimized. The multi-objective programming problem is converted to a series of single-objective programming problems by using the constraint approach. A set of Pareto optimal solutions are generated for a tensegrity grid to demonstrate the validity of the proposed method.

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Spatial Optimization Approaches to Redistricting for National Assembly Election: A Case Study on Yongin City (공간 최적화 기법을 이용한 국회의원 선거구 획정 -용인시를 사례로-)

  • Kim, Myung Jin;Kim, Kamyoung
    • Journal of the Korean Geographical Society
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    • v.48 no.3
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    • pp.387-401
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    • 2013
  • Redistricting of National Assembly Election has a significant effect on the results of election because it has a strong tendency to be performed with political intentions rather than the equivalent representativeness of population and region. This paper focuses on proposing an alternative for restricting of National Assembly Election in terms of implementation, that is, an procedural and systematic approach, not allowing for political or arbitrary intervention. A spatial optimization model conforming with criteria for political redistricting such as population equality, contiguity, and spatial compactness is developed and applied to Yongin City where are some controversy over the redistricting of the 19th National Assembly. Modeling results show that it is possible to derive National Assembly Election districts based on the information of basic spatial units without political consideration or arbitrary intervention. In addition, The districts derived from the model improved population equality compared with the existing districts.

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