基于遗传算法的汽车永磁发电机多目标优化设计

提出了一种基于遗传算法的汽车永磁发电机多目标优化设计。该设计通过改进的遗传算法进行多目标优化。改进的遗传算法采用二进制编码,规范化几何秩选择,混合交叉及均匀变异。优化结果表明,在单目标函数和多目标函数情形下均搜索到全局最优解,遗传算法为多目标优化提供了有效的途径。同时经过反复计算后,获得一些具有实用价值的经验数据,对永磁电机的设计起到一定指导作用。     

On Optimal Adaptive Prediction of Multivariate Autoregression

Abstract

The problem of asymptotic efficiency of adaptive one-step predictors for a stable multivariate first-order autoregressive process (AR(1)) with unknown parameters is considered. The predictors are based on the truncated estimators of the dynamic matrix parameter. The truncated estimation method is a modification of the truncated sequential estimation method that makes it possible to obtain estimators of ratio-type functionals with a given accuracy by samples of fixed size. The criterion of optimality is based on the loss function, defined as a sum of sample size and squared prediction error's sample mean. The cases of known and unknown variance of the noise model are studied. In the latter case the optimal sample size is a special stopping time. The simulation results are given.     

专业学位《高等生物分离工程实验》课程设计

生物分离工程是整个生物产业技术中的关键环节,而生物分离工程实验课程是生物工程专业学位教育中不可替代的内容。本文阐述了利用具有不同专业知识基础的专业学位硕士生的知识基础不同,选择不同实验内容。在实验设计中,强调知识点的模块化设计。通过学生参与设计,调动学生学习积极性。开展好实验设计,对培养专业型人才有重要作用。     

丹尼尔流动点在涂料配方设计中的应用

对于给定的树脂、颜填料体系,采用丹尼尔流动点理论对分散剂进行定性选择和用量试验,并将设计配方推广至生产应用。     

Can dendrimer based nanoparticles fight neurodegenerative diseases? Current situation versus other established approaches

For several decades, the treatment of central nervous system (CNS) disorders such as, for instance, Alzheimer’s disease (AD), Huntington’s disease (HD), and Parkinson’s disease (PD) represented an important challenge due to the difficulty in delivering drug molecules and imaging agents to the brain. Two strategies have been developed aimed at achieving the efficient delivery of drugs to the brain: invasive (e.g., temporary osmotic Blood Brain Barrier (BBB) opening, direct local delivery of nanoparticles with encapsulated CNS drugs etc.) and noninvasive approaches. As a part of the noninvasive approach among systemic delivery of drug molecules across BBB using nanocarriers, dendrimers represent promising therapeutics agents per se or nanocarriers of CNS drugs and for gene therapies. This original review emphasizes and analyzes the use of dendrimers as promising systems in the treatment of AD and PD, ischemia/reperfusion injury, neuroinflammation including cerebral palsy, neurological injury after cardiac surgery and particularly after hypothermic circulatory arrest, and for retinal degeneration purposes.     

硫化胶制样技术对红外光谱分析的影响

样品粒径对硫化胶网络主链α－亚甲基浓度影响较大,但对侧甲基浓度影响甚微。样品粒径减小会导致样品严重氧化,因此压片法红外光谱分析要严格控制样品粒径。样品浓度对分析结果也有较大影响。在样品粒径小于２μｍ、样品与溴化钾质量比为（１～５）：１０００时,可获得较为理想的红外光谱图。     

果汁机外罩壳注射模设计

根据某品牌果汁机外罩壳的形状特点,详细分析了其模具的结构和工作原理,设计了具有前模内滑块、斜滑块、穿孔滑块,后模滑块、斜顶等抽芯机构的注射模具,实现了外罩壳的注射成型。     

Designing one-sided group sequential clinical trials to detect a mixture alternative

We consider the construction of one-sided group sequential designs where the stopping rule includes boundaries for early stopping to accept for futility and to reject for efficacy. The traditional assumption that all patients have the same likelihood of benefiting from the treatment is sometimes unrealistic and can underestimate the required sample size. This motivates us to power the design for an alternative where the treatment group observations come from a mixture of normal distributions. For the proposed setting, we use standardized test statistics based on sample means, and the test turns out to be an L-optimal similar test. Stopping boundaries and arm size for the design are determined by Type I and Type II error spending equations. We demonstrate the need for larger arm sizes when trying to detect a mixture alternative compared to trying to detect a pure shift alternative. The unknown variance case is discussed. With the mixture model, we discuss a more general definition of treatment effect. The maximum likelihood estimator for the treatment effect is discussed.     

“立象以尽意”——论陶瓷设计的方法

陶瓷设计不仅要满足物质实用性的需要,同时也要满足人的精神审美需要。\"立象以尽意\"是中国古典美学思想、同时也是一种造物法则,该法则运用在陶瓷设计中,指的就是陶瓷的仿生设计、情感化设计等设计方法。此文从功能、造型、装饰等角度分析\"立象以尽意\"法则在陶瓷设计中的应用,以期使大家对中国陶瓷设计文化有更深入的理解。     

Improved sequential and accelerated sequential Procedures for estimating the scale parameter in a aniform distribution

Ghosh and Mukhopadhyay (1975a) and more recently Mukhopadhyay et al.(1983) have consideredsequential minimum risk point estimation of θ in a uniform (0,θ)population.The loss function has been squared error plus linear cost and θ has beencustomarily estimated by the sample maximum.In this paper,we consider instead the best scalarmultiple of the sample aximum as the estimator of θ.The percentage saving in the fictitious optimal fixed sample size as well as the percentage reduction in the corresponding minimum risk ar seen to be about 20.6X when compared with the Mukhopadhyay et al.(1983) cedure.Since thisamount of saving is quite substantial,we set out to develop     

基于遗传算法的干气密封双向槽统一模型与参数优化

通过提出表征能力更强的新型结构模型和引入全局寻优能力更强的智能优化算法以提高双向旋转槽干气密封的稳态密封性能。在综合分析国内外干气密封典型双向旋转槽结构特点的基础上,提出一种动压槽倾角可变的双向旋转槽统一模型。建立双向旋转槽干气密封的几何模型和数学模型,采用有限差分法求解端面膜压控制方程,获得开启力和气膜刚度等稳态性能参数。分析了动压槽倾斜角对干气密封稳态性能的影响规律,对比分析了不同速度条件下单因素优化、迭代优化和遗传算法优化等三种优化方法对提高双向旋转槽干气密封稳态性能的作用。结果表明：相较于以往双向树形槽干气密封单因素优化的结果,基于遗传算法的统一模型槽干气密封获得的开启力和气膜刚度显著提高,最大增幅分别达到6%和55%;在高速条件下,上游动压槽螺旋角为锐角,下游动压槽螺旋角为钝角的似机翼形双向旋转槽干气密封具有最大的开启力和气膜刚度。     

微通道内纳米流体传热流动特性

为提高微通道散热器的传热效率,需要对微通道进行结构优化设计。以热阻Rt和泵功Pp为目标函数,在Re=100的条件下,采用多目标遗传算法对文丘里管微通道的结构参数,如通道深度、收缩角度、喉颈宽度和扩散角度进行优化,通过遗传迭代计算得到Pareto优化解集,利用k-means聚类法对优化解集进行比较分析,通过强化传热因子η对各聚类点综合性能进行评价,得到最优的微通道结构。采用数值模拟方法,研究优化后的微通道结构的流动与传热特性。结果表明：当去离子水中加入纳米颗粒后微通道内的压降具有小幅度上升,但其流动阻力在相同Reynolds数的条件下并没有发生较大的变化。在文丘里管微通道喉部位置会产生喉部效应,强化纳米颗粒与微通道中流动工质的融合。熵产分析表明,传热熵随着Reynolds数的增大而减小,摩擦熵随着Reynolds数的增大而增大,不过总熵值中主要是传热熵占据主导地位。纳米流体随着体积分数的增加不可逆损失均小于去离子水。     

基于Kriging模型与遗传算法结合的RHCM成型工艺参数优化

为了提高高光无痕注塑成型(rapid heat cycle molding,RHCM)制品综合品质,提出了一种基于Kriging模型与遗传算法(genetic algorithm,GA)结合的工艺参数优化策略.将该策略应用于某空调柜机出风面板成型,以正交实验法规划实验,通过CAE分析获取实验样本数据,借助数据归一化法、线性加权法、直观分析法等数据处理方法,得到了对RHCM成型影响显著的工艺参数依次为保压时间、冷却时间、熔体温度、加热时间.然后引入Kriging建模理论,建立了RHCM成型制品综合品质与主要成型工艺参数的近似模型,采用GA对建立的近似模型在可行解空间搜寻最优解.得到的最优工艺参数为:加热时间36.9 s,熔体温度182.9℃,保压压力88.5 MPa,冷却时间51.3 s.最后,通过CAE分析和生产试制分别验证了该优化策略的可行性和合理性.     

激光粒度分析仪在微细粒级荧光粉粒度测量中的应用

采用激光粒度分析仪对某种微细粒级荧光粉运用不同的样品循环运动速度和加载超声波进行粒度组成与分布的测量。通过正态曲线叠加比较获得:该微细粒级荧光粉颗粒平均直径为4.128μm,中值为3.145μm,标准差为3.930μm,变异系数为95.10%,众数为4.048μm,并测得不同粒径颗粒所占的质量分数。结果表明,该方法是粉末粒度及粒度分布测量的准确方法。     

特殊换热网络算例优化与分析

换热网络综合属于混合整数非线性规划问题,具有严重的非凸、非线性特性。为探讨某些换热网络算例可能存在内部公用工程且年综合费用极低的特殊换热网络结构,本文采用了允许公用工程内置的无分流分级超结构模型。基于布谷鸟搜索算法,通过设置最小换热量阀值及以较小概率接受较差结构来指导换热网络结构进化,建立适用于求解换热网络综合问题的优化算法,并对特殊算例的优化结果进行分析。本文列举3个特殊算例,具有热流体的初始温度高于热公用工程的入口温度或热公用工程的进出口温差较大的特征,改进的布谷鸟搜索算法能够搜索到带有内部公用工程的换热网络结构,且年综合费用得到明显下降。结果表明：对于特殊算例,公用工程内置能够优化换热网络的热量分布,节约换热器面积,有效降低换热网络的年综合费用。