Advanced Materials Research Vols. 204-210

Abstract: The vehicle routing problem with multiple depots was considered in this paper, and a genetic algorithm for the proposed problem was designed to minimize the vehicle number and total travel distance. Performances are compared with other heuristics recently published in the literature, the computational results show that the proposed approaches produce high quality results within a reasonable computing time.

Abstract: Population diversity is one of the most important factors that influence the convergence speed and evolution efficiency of gene expression programming (GEP) algorithm. In this paper, the population diversity strategy of GEP (GEP-PDS) is presented, inheriting the advantage of superior population producing strategy and various population strategy, to increase population average fitness and decrease generations, to make the population maintain diversification throughout the evolutionary process and avoid “premature” to ensure the convergence ability and evolution efficiency. The simulation experiments show that GEP-PDS can increase the population average fitness by 10% in function finding, and decrease the generations for convergence to the optimal solution by 30% or more compared with other improved GEP.

Abstract: Hydraulic jet pump is one of the mixing-reaction equipments using high-speed jet for work force to deliver energy and mass of fluid. Many factors affect the efficiency of this pump, and the mechanism is very complex. The present work aims to study the influence of different hydraulic structures on the efficiency. Based on computational fluid dynamics, two-dimensional oil flow in hydraulic jet pump with different structural parameters (area ratio, throat length and spray distance) was simulated. Calculation results show that: area ratio determines the suction capacity, throat length determines the mixing efficiency, and spray distance determines the outlet pressure. Since numerical simulation method can reduce experimental expenses and design cycle, our approach may provide some references for safe design and engineering practice of hydraulic jet pump.

Abstract: To solve problem of the routing optimization and load balance in the selection of multimedia server,this paper is aimed to design an anycast routing algorithm based on hybrid strategy that combined ant colony optimazition algorithm with differential evolution algorithm,during the process of route discovery,considering not only the status of link,such as bandwidth,delay,but also introducing the server status,to discover a combination of the server and path which meet the requirement and achieve or near to the best.And then guiding the users’ request to the best server.

Abstract: To improve the control precision of robotic manipulator, fuzzy support vector machines control method for robotic manipulator was presented based on genetic algorithm and least square algorithm. Fuzzy algorithm was used to decouple joints. Using support vector machines, fuzzy logical control of complete process and treatment of non-linear signal were realized. The parameters of controller were optimized by hybrid learning algorithm. First, least square algorithm was used for off-line optimization to form support vector machines control system. Then, genetic algorithm was used for on-line optimization to get the optimal performance parameters of support vector machines and the optimal fuzzy proportional parameters. Simulation results of a two-link manipulator demonstrated that the control method designed gets tracking effect with high precision.

Abstract: Quantum principles is introduced in particle swarm optimization to optimize SVM, aiming that common optimization algorithms of SVM are easy to relapse into local extreme values and optimization result bad. Quantum particle swarm optimization can improve traverse property of particle, thus can overcome the limitation of local extreme values and optimize SVM well. Use the optimized SVM to control the motion of bio-mimetic robotic horse. And simulation results show that this algorithm can achieve the best control effect quickly and accurately.

Abstract: This study proposes a new method to search optimal parameters of BP networks based on improved ant colony algorithm. The algorithm proposed that each ant searches only around the best solution of the previous iteration with, which can reduce search space fast. is proposed for improving the solution performance to reach global optimum fairly quickly. Simulation results indicate that optimize parameters of BP networks with this method can not only overcome the limitations both the slow convergence and the local extreme values by basic BP algorithm, but also improve the learning ability and generalization ability.

Abstract: Merger and acquisition is currently the mainly way of power enterprise to pursue scale effect and improve competitiveness. So it is necessary to research the method to evaluate the merger effectiveness. In this paper, the common methods are analyzed, and a new factor analysis model based on the index-system-method is established. The comprehensive score gained from the model can stand for annual comprehensive performance of the merger company; then paired t-test the comprehensive scores of two different years; finally, whether the merger caused significant performance can be known.

Abstract: A method to decompose dynamic complex systems is proposed, that is, by using the dynamic inclusion principle and permutation transformation, complex system with information constrains of dynamic topology structure is decomposed as a group of pair-wise decoupled subsystems in the expanded space. Then according to the Lyapunov method, the connective stability of pair-wise subsystems is discussed by constructing Lyapunov functions in the case all isolated systems are stable, the conditions of connective stability for the expanded system are obtained, which are also adapt to the original system based on inclusion principle. Finally, the theorem and deduction of connective stability for the dynamic interconnnected complex system are given.

Abstract: Central air-conditioning energy consumption accounts for a large proportion of the buildings. And cold and heat source energy consumption accounts for about two-thirds of central air-conditioning system. For a research and development center in Shanghai, because cold and heat source capacity largely surpasses the actual demand, we propose to combine with cold sources of the two buildings. We call it "two-in-one" reconstruction. When cooling load is small, we use cold source in one building to support the two buildings. After implementation, by return on investment analysis, the average electric energy-saving rate is 9.6%. Investment can be recovered within one year.