基于Multisim2001仿真的集成稳压电源设计

集成稳压电源与一般分立元件的稳压电源相比较,具有性能优良、可靠性高、体积小、价格低廉的优点,在电子制作及仪器设备中得到广泛的应用。要得到满足性能要求的集成稳压电源,可以通过传统的设计来进行,但利用计算机结合Multisim2001仿真软件来设计集成稳压电源在实践中更具有深远的现实意义。     

太阳能路灯工作情况仿真研究

利用MATLAB/SIMULINK、MATLAB/SIMPOWERSYSTEMS仿真软件包对太阳能路灯系统在不同天气条件下的工作情况进行了仿真分析,并根据仿真数据对系统可能存在的问题提出了改进方法。     

基于Taguchi正交试验的一维装配成功率计算方法及其应用

针对全因子试验计算多组成环尺寸产品装配成功率试验次数较多、计算工作量较大等不足,提出一种基于Taguchi正交试验的产品一维装配成功率计算方法.首先根据Taguchi参数设计准则,将一维尺寸链中组成环尺寸作为Taguchi正交试验的因素,每个因素分为3个水平,制定正交试验表,进行正交试验,求解封闭环尺寸的均值和标准差,经计算获得装配成功率,然后采用极值法分析了各因素对装配成功率的影响.最后,以齿轮组件为实例运用Taguchi正交试验计算装配成功率,应用蒙特卡洛模拟法进行对比分析,结果表明该方法的有效性.这为产品一维装配成功率计算提供了一种新的途径.     

基于Solidworks Simulation码垛机械手末端执行器导杆静力学分析

文章利用SolidWorks建立码垛机械手末端执行器三维设计模型,并直接应用SolidWorks软件中的SolidWorks Simulation分析计算模块对码垛机械手末端执行器抓手导杆进行了有限元静力学分析计算,验证了采用SolidWorks建立三维数学模型,直接应用SolidWorks软件中的SolidWorksSimulation插件模块进行机械构件的有限元分析计算方法和步骤的正确性,有效避免了其它三维设计建模软件与分析计算软件之间的双项转换操作和数据转换缺陷等问题,对相关工程技术人员具有一定参考价值,并提供了一种实用的分析计算方法。     

On the optimal design of the randomized unbiased Monte Carlo estimators

We consider a class of unbiased Monte Carlo estimators and develop an efficient algorithm to produce the distribution of the optimal random truncation level. We establish the convergence and optimality results of the associated algorithm and also derive its exact complexity. We find this algorithm has a much lower complexity as compared to the existing one in the literature. The proposed algorithm is also applicable to optimization problems arising in supply chain management, such as economic reorder interval problem.     

Quadratic hedging for sequential claims with random weights in discrete time

We study a quadratic hedging problem for a sequence of contingent claims with random weights in discrete time. We obtain the optimal hedging strategy explicitly in a recursive representation, without imposing the non-degeneracy (ND) condition on the model and square integrability on hedging strategies. We relate the general results to hedging under random horizon and fair pricing in the quadratic sense. We illustrate the significance of our results in an example in which the ND condition fails.     

Rotational Forms of Large Eddy Simulation Turbulence Models

In this paper the authors present a derivation of a back-scatter rotational Large Eddy Simulation model,which is the extension of the Baldwin&Lomax model to nonequilibrium problems.The model is particularly designed to mathematically describe a fluid filling a domain with solid walls and consequently the differential operators appearing in the smoothing terms are degenerate at the boundary.After the derivation of the model,the authors prove some of the mathematical properties coming from the weighted energy estimates,which allow to prove existence and uniqueness of a class of regular weak solutions.     

Investigation of mini-hydrocyclone performance in removing small-size microplastics

Large amounts of microplastics (MPs) have been found in rivers and oceans, bringing great harm to aquatic animals, plants, even human beings. However, the effective removal method of MPs, especially those with small sizes (5–20 μm) is still lacking. This work presents mini-hydrocyclones to remove 10 μm (average size) diameter MPs. The removal performance of nine mini-hydrocyclones with different diameters of spigot and vortex finder is examined experimentally and numerically. The performance of the designed cyclones is evaluated in terms of recovery, water split, concentration ratio and pressure drop. The results show that mini-hydrocyclones are applicable to removing small-size MPs with the maximum concentration ratio at 2.16 and the particle recovery at 51%. The flow characteristics inside the mini-hydrocyclones are analyzed in detail. It is shown that the distributions of water axial velocity and radial velocity could collectively affect the behaviors of small-size MPs in mini-hydrocyclones. Specifically, a larger amount of water split could entrain more fine particles to underflow. Meanwhile, a less frequent alternation of radial velocity between the positive and negative directions on the same side of the cyclone should benefit the removal of small-size MPs.     

应用Flow Simulation工具对电源内部热场的仿真分析

 从电源的数据模型、分析项目、材料数据库的建立、边界条件定义、热源定义、设定求解目标与计算、结果查看与应用这几个方面,来介绍如何应用Flow Simulation工具来实现对电源内部热场的仿真分析.通过对仿真结果的查看与应用,来预测开发设计中热设计的效果,并将此种电源批量投入使用.     

A stochastic multi-period industrial hazardous waste location-routing problem: Integrating NSGA-II and Monte Carlo simulation

The present study extends a multi-objective mathematical model in the context of industrial hazardous waste management, which covers the integrated decisions of three levels with locating, vehicle routing, and inventory control. Analyzing these decisions simultaneously not only may lead to the most effective structure in the waste management network, but also may reduce the potential risk of managing the hazardous waste. Furthermore, because of the inherent complexity of the waste management system, uncertainty is inevitable and should be acknowledged to guarantee reliability in the decision-making process. From this perspective, the proposed model is novel in the following three aspects: (1) shifting from a deterministic to stochastic environment; (2) considering a multi-period planning horizon; and (3) incorporating the inventory decisions into the problem. The problem is formulated as a multi-objective stochastic Mixed-Integer Nonlinear Programming (MINLP) model, which can be easily converted into a MILP one. In terms of methodological contribution, a new simheuristic approach that is an integration of Non-Dominated Sorting Genetic Algorithm-II (NSGA-II) and Monte Carlo simulation is developed to overcome the stochastic combinatorial optimization problem of this study. Our findings verify the efficiency of the proposed approach as it is able to find a high-quality solution within a relatively reasonable computational time.