In an emergency evacuation,the free evacuation of pedestrians can make the entire evacuation process slow and *** limit the free behavior of pedestrians and reduce the interaction between pedestrians,a reasonable layo...
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In an emergency evacuation,the free evacuation of pedestrians can make the entire evacuation process slow and *** limit the free behavior of pedestrians and reduce the interaction between pedestrians,a reasonable layout of the guider can improve the efficiency and safety of *** to set the number,location,and exit allocation of guiders requires further *** the current study,we transform the evacuation into a multiobjective optimization problem.A two-layer optimization framework is *** the upper level,the improvednsga-ii multi-objective algorithm is introduced to generate the favorable guider layout,and a chromosome fragment deletion operator is added to improve the optimization *** the lower layer,the agent movement simulation model is used to simulate the evacuation dynamic of crowd under the favorable guider *** variables of this multi-objective solution model in the upper layer are the number and location of the *** evacuation time and agent movement cost are calculated by the lower layer simulation as the objective values of the solution sample,and guide the iterative search process to obtain more reasonable optimization *** developed model is verified and then applied to a fictional *** number,initial position and exit allocation of guiders are obtained by optimizing the iterative *** results show that the near optimal solution can be applied in various visibility conditions,and the evacuation efficiency is much higher than that of unguided *** optimization framework can provide theoretical and methodological support for emergency evacuation planning.
This paper studies the flight path optimization problem of air cargo companies in aviation line alliance. There are two limitations in this paper. One is to limit of the number and location of airbases and capacity in...
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This paper studies the flight path optimization problem of air cargo companies in aviation line alliance. There are two limitations in this paper. One is to limit of the number and location of airbases and capacity in the air network. The other is to limit of flight time and airspace capacity of full cargo aircraft in actual operation. Considering the influence of alliance on operation, the selection probability of air alliance is introduced. It is assuming that all cargo aircraft is one type, the unit transportation cost of every aviation line is the same as each other, the queuing problem of aircraft landing is not considered, and the network transportation demand of itself must be completed by an airline. It proposes a directed aircraft fleet routing problem optimization model (SMDDDAAAFRPTW) with multi-airbase stochastic and time constraints to minimize total operating cost and flight distance. Using the multi-objective optimization algorithmnsga-ii by most scholars, and improving the initial solution generation step, introducing Genetic engineering into cross-mutation to solve the optimal number and location of air bases and fleet routing of multiple aircraft. Comparing with the weighted method and ant colony algorithm, it shows that the improved nsga-ii algorithm is effective and has better computational efficiency. The results show that the more segments are selected for outsourcing, the lowest cost of network and the lowest carbon emission. This kind of decision-making behavior is only suitable for the initial operation phase of the enterprise.
Aiming at the power optimization control problem of front-end speed regulation (FESR) wind turbine, when the wind speed above rated wind speed, an optimal control strategy of variable pitch and variable torque based o...
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Aiming at the power optimization control problem of front-end speed regulation (FESR) wind turbine, when the wind speed above rated wind speed, an optimal control strategy of variable pitch and variable torque based on improved nsga-ii algorithm is proposed. For this strategy, the reverse learning mechanism was used to initialize and evolve, and the crossover probability and mutation probability were adjusted dynamically based on the exponential distribution. A fuzzy comprehensive evaluation was used to get the best solution from the non-inferior solutions. The objective function was established upon the goals of the constant output speed for hydraulic speed converter and the smoothness of FESR's output power. And pitch angle and vane opening angle were optimized by the improved nsga-ii algorithm. Afterward, the optimization control algorithm has been validated through simulation experiment to a 2MWFESR. The simulation results show that the output power of FESR was smoothed, and the speed fluctuation and power fluctuation of FESR were also reduced, better control performance is thus achieved. Therefore, it is feasible and effective to optimize the control of FESR by the improved nsga-ii algorithm proposed in this paper.
The growing need of responsiveness for enterprises facing market volatility raises a strong demand for flexibility in their human resource management. This paper presents a multi-objective model for Multi-skill Projec...
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ISBN:
(纸本)9781728115665
The growing need of responsiveness for enterprises facing market volatility raises a strong demand for flexibility in their human resource management. This paper presents a multi-objective model for Multi-skill Project Scheduling Problem. We propose a new wage distribution method in which different perform efficiencies of human resources are taken into account. The model aims at minimizing project duration and project costs concurrently. An improved nsga-ii algorithm is designed to solve the model. The algorithm introduces a multi-dimensional chromosome coding scheme to identify the priorities and staff allocation of each activity. Special chromosome crossover and mutation operation are employed to address resource conflicts and constraint violations. Eventually, A case study is presented to verify the efficiency of the proposed approach.
To improve the energy efficiency and output power of the piston compressed air engine (CAE), a mathematical model of its working process was set up. With the use of the MATLAB/Simulink software for simulation, the inf...
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To improve the energy efficiency and output power of the piston compressed air engine (CAE), a mathematical model of its working process was set up. With the use of the MATLAB/Simulink software for simulation, the influences of the bore-to-stroke ratio, intake pressure and valve lift on the performance of the engine were obtained for the analysis of the energy efficiency and the output power. Moreover, to optimize the energy efficiency of the engine with the given output power, an improvednsga-ii was introduced, and a series of optimization intake pressures and valve lifts was obtained. When the output power value is about 2 kW, the intake pressure and the intake valve lift can be set to 1.99 MPa and 9.99 mm, the energy efficiency is highest: 31.17%. Finally, that the improvednsga-ii is superior to nsga-ii in proximity and diversity has been proved. This research can be referred in the optimization of the piston CAE and provides a method for the energy efficiency optimization study.
Job-shop scheduling is the very important, but weak part in the integrated manufacturing system. In view of the Job-shop scheduling characteristics for batch production of enterprises, this article analysised batch pr...
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ISBN:
(纸本)9783037857649
Job-shop scheduling is the very important, but weak part in the integrated manufacturing system. In view of the Job-shop scheduling characteristics for batch production of enterprises, this article analysised batch production scheduling problem in detail;then put out a workshop Intelligent Scheduling Optimization technical framework which contained six-stories. And study the basic theory and key technology of this structure framework in-depth, then proposed object-oriented technology which based on improved tabu search algorithm and nsga-iialgorithm to achieve the intelligent optimization targets, and in the experiment proved it is practical and effective.
The modern embedded multimedia electronic devices rely on dynamically-allocated data structures to store and process their data, as a result, the demand of its memory capacity and dynamic are increasing unceasingly. I...
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ISBN:
(纸本)9783037852132
The modern embedded multimedia electronic devices rely on dynamically-allocated data structures to store and process their data, as a result, the demand of its memory capacity and dynamic are increasing unceasingly. In order to better solve the memory application optimization in embedded device, this paper represents multimedia application's dynamic data structures optimization flow and improved or modified nsga-ii multi-objective evolutionary algorithm (Mnsga-ii), and uses three objective functions: embedded device's memory accesses, memory use and energy consumption. The Mnsga-iialgorithm adopts repeat crowded distance sorting tactics to improve nsga-ii based on keeping the advantage of the original nsga-ii for multi-objective optimization problem. The experiment results show that Mnsga-ii has better performance of the convergence and the diversity of solutions than original nsga-ii, and the optimal dynamic data structure implementation is successful by performing our method for one real embedded multimedia device's memory application.
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