14 results
Search Results
2. The property of search strategies of swarm intelligent algorithms and their influences on stagnation.
- Author
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CHEN Jun-feng and WU Tie-jun
- Subjects
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SWARM intelligence , *ALGORITHMS , *ANIMAL behavior , *MATHEMATICAL optimization , *STOCHASTIC convergence - Abstract
Swarm intelligent algorithms are derived from the simulation of natural evolution or collective behavior of animals to seek solutions of complicated optimization problems by exploring and exploiting the search space efficiently and effectively. Through the analysis on the search characteristics of swarm intelligent algorithms, the concept of solution set diversity is introduced in this paper according to the infrastructural changes of solution sets in search processes. Two categories of fundamental search strategies, i.e. the diversification search and the intensification search, are then defined and their influences on the stagnation of solution sets evolution are investigated on the basis of the solution set diversity. It is proved in this paper that an intensification strategy inevitably leads candidates solution to a single solution, which is one of the main sources of stagnation; while a diversification strategy is able to reach any point of the coding space from each initial candidate solution, i.e., the whole searching space is the reachable region of the diversification strategy, but the convergence of the algorithm cannot be guaranteed. Three popular swarm intelligent algorithms, i.e. the canonical generic algorithm, the ant colony system and the discrete particle swarm optimization, are tested with a benchmark problem, and the results support the theoretical conclusions. [ABSTRACT FROM AUTHOR]
- Published
- 2013
3. Optimization of the batches processing modes and resource scheduling for mixed-model manufacturing system of multi-variety and small-batch considering handling time.
- Author
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KONG Ji-li and JIAGuo-zhu
- Subjects
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CONTINUOUS time models , *ALGORITHMS , *MANUFACTURED products , *MATHEMATICAL optimization , *EQUIPMENT & supplies - Abstract
This paper, based on the consideration of the handling time, aimed to conduct a study on the optimization of the batches processing modes and resource scheduling for the mixed-model manufacturing system. The time models of the processing and handling for batch parts were established in order to obtain the solutions to the makespan and optimize the handling frequency. In this foundation, a principle was analyzed for determining the optimum processing sequencing. Besides, an optimization algorithm of the mutual-aid teams was also designed to schedule the handling equipments needed by the optimum processing sequencing. The results show that the study in this thesis can provide effective solutions to the makespan of batch parts, optimize the handling time and frequency, acquire the optimum processing sequencing, and schedule the resources of the handling equipments sensibly. [ABSTRACT FROM AUTHOR]
- Published
- 2014
4. Some properties of grey differential equation GM(1,1,β).
- Author
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LI Xi-can, YUAN Zheng, ZHANG Guang-bo, and CHENG Shu-han
- Subjects
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DIFFERENTIAL equations , *MATHEMATICAL optimization , *ALGORITHMS , *CITY dwellers , *INCOME , *ECONOMIC history - Abstract
As to the applied range and optimization of grey forecast model, according to the principle that grey GM(1,1) model's parameters are grey and adjustable, the connotation model and parameter packet formulas of GM(1,1, β) were put forward in this paper, and some properties of the model and model's optimization algorithm was analyzed. The results show that the objective valuing region of parameter a of GM(1,1, β) model is (-∞+ ∞), and the objective valuing region of parameter a of GM(1,1) model is (- 2,+2), the objective valuing region of parameter a is determined by the background value coefficient, and it has nothing with raw data sequence; GM(1,1, β) grey differential equation completely suits for the homogeneous exponential function series. Finally, the example of simulating and forecasting the per capita income of urban dwellers in China shows that the grey differential equation GM(1,1, β) is valid. [ABSTRACT FROM AUTHOR]
- Published
- 2014
5. Optimization model based on discrete Morse theory.
- Author
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ZHANG Jian-ping and LIU Xi-yu
- Subjects
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MORSE theory , *CALCULUS of variations , *MATHEMATICAL optimization , *ALGORITHMS , *TRIANGULATION - Abstract
The paper discussed characteristics of Forman theory and presented an optimization model based on discrete Morse theory, which could obtain an optimal value or approximate optimal one by the algorithm of constructing a discrete Morse function in 3-dimensional space. It is a radical attempt. The experimental results show that this model is effective for applications and especially for optimization problem of a large amount of data. [ABSTRACT FROM AUTHOR]
- Published
- 2014
6. A Memetic particle swarm algorithm for dynamic multi-modal optimization problems.
- Author
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WANG Hong-feng, WANG Na, and WANG Ding-wei
- Subjects
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MATHEMATICAL optimization , *ALGORITHMS , *PARTICLE swarm optimization , *DYNAMICS , *MEMETICS - Abstract
Many real-world optimization problems are both dynamic and multi-modal, which require an optimization algorithm not only to find as many as possible optima under a specific environment but also to track their trajectory over dynamic environments. To address this requirement, this paper investigates a memetic particle swarm algorithm for dynamic multi-modal optimization problems. Within the framework of the proposed algorithm, a new speciation method is employed to locate multiple peaks and an adaptive local search method is also hybridized to accelerate the exploitation of species generated by the speciation method. In addition, the re-initialization schemes are introduced into the proposed algorithm in order to further enhance its performance in dynamic multi-modal environments. Based on the moving peaks benchmark problems, experiments are carried out to investigate the performance of the memetic particle swarm algorithm in comparison with several state-of-the-art algorithms in the literature. The experimental results show the efficiency of our proposed algorithm for dynamic multi-modal optimization problems. [ABSTRACT FROM AUTHOR]
- Published
- 2013
7. Two-stage heuristic algorithm for multi-depot vehicle routing problem with time windows.
- Author
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YU Bin, JIN Peng-huan, and YANG Zhong-zhen
- Subjects
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VEHICLE routing problem , *COMBINATORIAL optimization , *ALGORITHMS , *HEURISTIC algorithms , *MATHEMATICAL optimization - Abstract
Vehicle routing problem (VRP) plays a vital role in logistics research. The multi-depot vehicle routing problem with time windows (MDVRPTW), an extension of VRP with time windows (VRPTW), is very complicated to be solved. This paper presented a two-stage heuristic to solve MDVRPTW. In the two-stage heuristic, aggregation-based clustering algorithm was firstly proposed to transfer MDVRPTW to several VRPTWs, and ant colony optimization (ACO) was developed to optimize each VRPTW. Two improvement strategies: crossover operation and adaptive ant-weight strategy, are designed to improve ACO. The performance of the two-stage heuristic was examined by use of some classic instances. Results show that the two-stage heuristic is a powerful tool for MDVRPTW. [ABSTRACT FROM AUTHOR]
- Published
- 2012
8. The bi-level optimization model of the compound system for basin initial water right allocation.
- Author
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Wu Dan, Wu Feng-ping, and Chen Yan-ping
- Subjects
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WATER rights , *GEOLOGICAL basins , *MATHEMATICAL optimization , *DECISION making , *ALGORITHMS - Abstract
The paper took different regions and regional industries as initial water right allocation objects in the basin; the compound system for basin initial water right allocation was given; the connotation and objective of the compound system was analyzed; and the bi-level optimization model of the compound system optimization was established to allocate water right of different regions and regional industries, and eliminate the water conflict and contradiction among regions, embody the fairness and efficiency of different regions' water right, prevent different industries from the vicious water right competition, optimize comprehensive benefit of society-economy-ecology in the basin. Meanwhile, according to the interactive decision-making theory, the model algorithm was put forward. The case analysis verified the effectiveness of the model. [ABSTRACT FROM AUTHOR]
- Published
- 2012
9. Inward-outward crossover based genetic algorithm for constrained optimization problem.
- Author
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Liu Da-lian and Xu Shang-wen
- Subjects
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GENETIC algorithms , *CONSTRAINED optimization , *MATHEMATICAL optimization , *PARTICLE swarm optimization , *ALGORITHMS , *NUMERICAL analysis - Abstract
Considering that the global optimal solutions often locate on or near the boundary of the feasible region for many constrained optimization problems, a novel genetic algorithm was proposed in this paper. The basic idea of the proposed algorithm was to put feasible solutions and infeasible solutions into two different containers respectively. Subsequently, a new designed crossover operator (named inward-outward crossover operator) was used to a feasible solution and a infeasible solution, then a line search along a potential decent direction was used to improve the offspring so as to find a good solution on or near to the boundary of feasible region. By this search procedure, the possibility for obtaining the globally optimal solution is obviously enhanced, and similarly, the convergent speed is also strengthened. The "particle swarm mutation" inherited the advantages of Particle Swarm Optimization (PSO) algorithm and searched for the potential solution along the direction of the best current particle and the direction of the best individual of the whole swarm in the past. Selection operator retained a constant rate of infeasible solutions. Numerical results indicate that the proposed algorithm can be efficient to get global optimal solutions or near to them in smaller population and less iteration times. [ABSTRACT FROM AUTHOR]
- Published
- 2012
10. A Novel Error Compensation Term in Velocity Updating of SINS under Coning Angular Motion Conditions.
- Author
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YOU Jin-chuan, QIN Yong-yuan, MEI Chun-bo, and XIA Jia-he
- Subjects
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ALGORITHMS , *MATHEMATICAL optimization , *SPEED measurements , *ERROR analysis in mathematics , *VIBRATION (Aeronautics) - Abstract
Coning effects must be accurately compensated in the attitude updating of the classical strapdown inertial navigation integration algorithm. These effects are not involved in the velocity updating, though the attitude change is being taken into it. The novel velocity error term induced by the coning correction is studied in this paper. These effects as the gyro angular increment data have the influence on the velocity updating in the same way. For the assumed linear ramp model, a two-sample compensation algorithm for the novel velocity error term is deduced in detail by using the two successive integrated angular rate increment and specific force increment measurements. The weighting coefficients are then optimized for best average performance in a specific environment; i. e. the body is exposed to a coning angular vibration about the x axis of the body frame combined with a linear vibration at the same frequency and in phase along the z axis. The simulation results validate that the two-sample optimization algorithm can compensate the integrated term of the novel velocity error effectively. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
11. Interval Kalman Filtering Algorithm for High Dynamic Navigation and Positioning.
- Author
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SHEN Yue, ZHANG Lei, FU Zhong-qian, and WANG Jian-yu
- Subjects
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KALMAN filtering , *ALGORITHMS , *MATHEMATICAL optimization , *MATRICES (Mathematics) , *ELECTRONIC noise - Abstract
In traditional Kalman filtering algorithms, optimization estimation cannot be achieved for practical problems because the dynamics system model and noises are unknown. Firstly the impacts of various error sources and interval matrix operations in the traditional Kalman filter are analyzed. The analysis shows that the interval operation can ensure the completeness of set mapping but can not be the optimization. Based on the analysis, a new interval Kalman filtering algorithm is proposed in this paper. In the algorithm, various error sources are reduced to a priori estimation interval and a posterior estimation interval and the interval intersection set operation is adopted to achieve the optimization. This algorithm has comparable computational complexities with the traditional one. Simulations show that the proposed algorithm can achieve a 2dB gain over the traditional Kalman filter in high dynamic navigation and positioning with time-varying noises. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
12. Design of a Kind of Reduced-Order Fault Detection Filtering Algorithm and Its Application in Space Vehicles.
- Author
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WANG Qing, WANG Ming-ming, and DONG Chao-yang
- Subjects
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ALGORITHMS , *MATHEMATICAL optimization , *MATRICES (Mathematics) , *PERTURBATION theory , *LINEAR matrix inequalities , *HELICOPTERS - Abstract
Under the condition of a short sampling period, limited resource and computational capacity, a method for designing reduced-order fault detection filtering algorithm is proposed in this paper. Small perturbation theory and a Taylor series expansion about the balance point are used to linearize the nonlinear dynamics equations of space vehicles. Then the reduced-order fault detection filter is designed for the linear state-space equation. The problem of feasible solution of the reduced-order fault detection filtering algorithm is transformed into a nonconvex optimization problem expressed in terms of linear matrix inequalities. The local optimal solution of the nonconvex optimization is achieved by an alternate mapping algorithm. The reduced-order fault detection filtering algorithm is obtained under the condition that the feasible solution exists. Finally, the reduced-order fault detection algorithm is applied to the fault detection of the yaw control system in a small-scale autonomous helicopter. Simulation results are presented to show effectiveness of the proposed approach. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
13. Study on Design Method of Low-Thrust Phasing Maneuvers for Earth Circle-Orbit Satellites.
- Author
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WANG Shuai, SHANG Hai-bin, CUI Ping-yuan, and HUANG Xiang-yu
- Subjects
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TELECOMMUNICATION satellites , *MATHEMATICAL optimization , *GEOSYNCHRONOUS orbits , *GEOSTATIONARY satellites , *ALGORITHMS - Abstract
Low-thrust phasing maneuver design of Earth circle-orbit satellites is researched in this paper. A semi-analytical phasing parameter analysis method is proposed, and based on that an efficiently accurate design method is developed. First, according to the influence law of thrust direction on phase change rate, functional relationship between phasing parameters are derived by using orbit averaging technique and thrust direction assumption. The key phasing parameters can be obtained by using simple differential correction. Then, the fuel-optimal phasing orbit design under the condition of complex constraints based on a perturbation model is transformed into a multi-parameter optimization problem by discretizing control law. With the initial guess obtained by the analysis method, the problem can be solved rapidly by using a sequential quadratic programming algorithm. Finally, the simulation results of Geosynchronous orbit low-thrust phasing transfer is presented, it is shown that feasible initial guess can be provided with the analytical method for phasing orbit design, and by using the robust design method, low-thrust phasing trajectory design problem can be solved effectively under the perturbation model. [ABSTRACT FROM AUTHOR]
- Published
- 2013
- Full Text
- View/download PDF
14. A Blind Signal Extraction Algorithm Based on Cyclostationary Constraint.
- Author
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Fan Yun, Wang Xiang, Huang Zhi-tao, and Zhou Yi-yu
- Subjects
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CYCLOSTATIONARY waves , *DIGITAL signal processing , *MATHEMATICAL optimization , *ALGORITHMS , *TELECOMMUNICATION satellites - Abstract
Signals of interest (SOIs) extraction is a vital issue in the field of communication signal processing. In this paper, the cyclostationary property of communication signals is incorporated into the constrained ICA (cICA) framework to form a new constrained optimization problem. The approach incorporates cyclostationarity constraints in the ICA process to perform separation and selection of the SOIs simultaneously. Numerical simulations demonstrate the effectiveness and higher performance of the proposed algorithm compared with the conventional ICA algorithms such as FastICA. [ABSTRACT FROM AUTHOR]
- Published
- 2012
- Full Text
- View/download PDF
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