Dynamic characterization of Built-In Current Sensors based on PN junctions: Analysis and experiments

The goal of this work is to analyze the performance of PN junction-based Built-in Current Sensors (BICS) for I _DDQ testing. Two types of BIC Sensors are analyzed: one based on a simple PN junction as the sensing element (DBICS), and the other based on a lateral BJT (PBICS). The sensitivity, speed and performance of the BICS are studied by showing their dependence on circuit parameters. Design constraints of such sensors in order to achieve performance criteria on CUT and BICS are analyzed. The dynamic analysis of the BICS is compared with experimental results when the PN junction BICS are used on a CMOS circuit.     

Process optimization and characterization of silicon microneedles fabricated by wet etch technology

In this research, we have optimized a fabrication technique for manufacturing microneedle arrays in standard silicon wafer ((100) orientation) using potassium hydroxide (KOH) wet etching. The etch behaviour of silicon was simulated for different mask shapes and sizes using SIMODE software. In the context of the fabrication process, we demonstrate the influence of the mask design and the processing environment such as etching parameters and etch bath conditions on the formation of silicon microneedle structures (needle height up to 300 μm) and its reproducibility. Single needle shear tests have been carried out to characterize the mechanical stiffness of fabricated microneedles.     

基于分离模块航天器的激光输能技术研究

随着航天任务的日趋复杂化,航天器能源需求越来越高,将激光输能技术运用于航天器能源供给越来越受到重视。针对当前地基激光输能技术的发展现状和不足,本文从分离模块航天器的设计理念出发,研究了一种基于模块化航天器的天基激光输能技术。介绍了这种天基激光输能的输能模式和输能过程,分析了其相对于地基激光输能的优势。根据当前激光技术和航天技术的发展现状,分析了实现天基激光输能方式需要解决的五个关键技术,为分离模块航天器的能量供给提供了一种新的解决方案。     

Reliability estimation and tolerance limits for Laplace distribution based on censored samples

In this paper, we first present an estimator for the reliability function based on the best linear unbiased estimators (BLUEs) of the location and scale parameters, μ and σ, for the Laplace distribution based on Type-II censored samples. We show that this estimator is almost unbiased at varying levels of reliability. Next, we determine through Monte Carlo simulations the values of the tolerance factor t_γ that are necessary for the construction of lower and upper tolerance limits for the distribution. We also illustrate how these tables for tolerance limits could be used to determine lower confidence limits for the reliability. Finally, we present an example to illustrate the methods of inference developed in this paper.     

Point and interval estimation for Gaussian distribution, based on progressively Type-II censored samples

The likelihood equations based on a progressively Type-II censored sample from a Gaussian distribution do not provide explicit solutions in any situation except the complete sample case. This paper examines numerically the bias and mean square error of the MLE, and demonstrates that the probability coverages of the pivotal quantities (for location and scale parameters) based on asymptotic s-normality are unsatisfactory, and particularly so when the effective sample size is small. Therefore, this paper suggests using unconditional simulated percentage points of these pivotal quantities for constructing s-confidence intervals. An approximation of the Gaussian hazard function is used to develop approximate estimators which are explicit and are almost as efficient as the MLE in terms of bias and mean square error; however, the probability coverages of the corresponding pivotal quantities based on asymptotic s-normality are also unsatisfactory. A wide range of sample sizes and progressive censoring schemes are used in this study.     

Real-time grasping-force optimization for multifingered manipulation: theory and experiments

Real-time grasping-force optimization is a vital problem in dextrous manipulation with multifingered robotic hands. In this paper, we review two prominent approaches that have recently been proposed for this problem, and identify their common need for an appropriate initial condition to start the recursive algorithms. Then, we propose an efficient algorithm that combines a linear-matrix-inequality method with a gradient method for automatic generation of initial conditions. By incorporating the initial conditions, optimal grasping forces can be generated efficiently in real time. Finally, we implement and evaluate all the algorithms for grasping-force control in the Hong Kong University of Science and Technology three-fingered hand platform. Experimental results demonstrate the efficiency of the proposed approach.     

Testing exponentiality based on the Kullback-Leibler information with the type II censored data

We express the joint entropy of order statistics in terms of an incomplete integral of the hazard function, and provide a simple estimate of the joint entropy of the type II censored data. Then we establish a goodness of fit test statistic based on the Kullback-Leibler information with the type II censored data, and compare its performance with some leading test statistics. A Monte Carlo simulation study shows that the proposed test statistic shows better powers than some leading test statistics against the alternatives with monotone increasing hazard functions.     

基于Proteus的微机原理实验仿真

介绍了微机原理实验教学中存在的问题,并依据教学实践,对微机原理课程中的一些重点和难点内容,探讨了利用Proteus7．5SP3进行仿真的教学方法。实践表明,该方法能加深学生对微机原理课程相关内容的理解,激发学生的学习积极性,锻炼学生利用所学知识进行软硬件综合开发的能力。     

Process optimization for 123 and Bi-based superconductors

The development of pure phase 123 and Bi-based 2223 superconductors has been optimized. The pre-heat processing appears to be a very important parameter in achieving this objective. In addition, the synthesis of pure phases in the Bi-based system involves effects due to oxygen partial pressure, time and temperature. The optimization of this processing is a key step towards the successful continuation of the superconducting materials development, i.e. in substitutions, c-axis orientation, melt-sintering processes, and in synthesizing single crystals.An example of optimized bulk substitution is the 70% limit of Sr for Ba substitution in the yttrium-based 123 superconductor. In a nominal composition containing no barium, a majority 123 phase has also been observed, though this phase is apparently not superconducting. In the Bi-based system, substitution of Sb and Pb for Bi has been obtained in the 2223 phase. The Sb substitution into the pure phase has no apparent advantage over the parent Bi compound or the Pb-substituted phase.Orientation/melt-sintering effects include the extreme c-axis orientation of yttrium 123 and of the bisumuth 2223, 2212 and 2201 phases. Surface orientation of all three Bi-based phases can be obtained from one sample of a specific nominal bulk composition. The surface orientation for both series of samples is dependent upon a number of factors including pre- heat processing, exact composition and/or extraneous phases present, heat rates, temperatures, and times.A procedure for establishing Sr substitution for Ba into 123 single crystals has been determined. Systematic substitution of up to 30% Sr for Ba in the structure has been successful. This procedure as well as those above will be described and discussed.     

细菌觅食差分粒子群算法的无功优化方法

电力系统无功优化是以网损最小化且保持良好电压水平为目的。提出了细菌觅食差分粒子群算法（DEBFO）,并首次应用于电力系统无功优化问题。趋化操作的交叉算子可提高局部搜索能力,变异算子可加强全局搜索能力,繁殖操作使细菌寻优速度加快,迁徙操作避免了细菌早熟。Matlab仿真结果表明DEBFO具有较强的全局寻优能力,收敛速度快,鲁棒性好,能够更有效地解决电力系统无功优化问题。     

基于混沌优化的双种群量子粒子群算法

提出了一种基于混沌优化的双种群量子粒子群算法(BCQPSO)。算法利用混沌序列随机生成两个种群,在子种群中惯性权重分别采用不同的更新策略,并通过种群间的融合和变异进行信息交互,提高了算法的收敛速度和解空间的遍历范围。仿真实验结果表明,所提算法具有很好的搜索能力和优化效率。     

BLUEs of location and scale parameters of laplace distribution based on type-II censored samples and associated inference

In this paper, we first present the Best Linear Unbiased Estimators (BLUEs) of the location and scale parameters, μ and σ, of the Laplace distribution based on Type-II censored samples. We next present some simulated percentage points for three pivotal quantities which will enable one to construct confidence intervals or carry out tests of hypotheses for the parameters μ and σ. Finally, we present an example to illustrate the methods of inference developed in this paper.     

融合损失优化的行人重识别方法

行人重识别的目的是通过深度学习检索出数据集中存在特定身份的行人,在行人重识别算法中最理想的优化目标是最小化类内距离,最大化类间距离.本文提出一种对损失函数进行优化改进的行人重识别方法.通过在分类损失上添加了额外的监督信号,使其配合联合训练.在保持类间判别力的基础上,使训练出的特征有较强的内聚性,约束了类内紧凑性,有效提...     

基于遗传算法的排产优化方法

针对单件小批量生产车间的优化排产问题,采用遗传算法进行研究,设计了一种分组编码方案,提出了可处理零部件间装配关系的适应度函数算法。介绍了遗传算法在车间优化排产中的实现方法及结果,重点讨论了编码方案及适应度函数设计。基于此算法,开发了生产作业计划排产软件,可完成顺排产与倒排产的自动排产,实现工艺排产的智能化。     

基于ASPS的覆盖优化方法

覆盖优化是无线优化的核心之一,扫频数据是进行覆盖优化的最佳数据源,本文介绍了ASPS软件扫频模块的主要功能,并结合案例重点阐述了使用ASPS软件进行覆盖优化的流程和方法.     

基于对标学习的智能优化算法

科研、工程和管理中的很多问题都可以转化为优化问题。应用于这些优化问题的各种方法本身就是各种模型,设计不同的方法即设计不同的模型。将标杆管理理念建模成为一种用于单目标优化问题的元启发式搜索方法。基于奥卡姆剃刀原则,摒弃了复杂的操作算子的概率调优规则,用一个简单的框架来组织核心算子,从而达到许多组合算法的搜索效果。     

A highly efficient OLED based on terbium complexes

A neutral ligand 9-(4-tert-butylphenyl)-3,6-bis(diphenylphosphineoxide)-carbazole (DPPOC) and its complex Tb(PMIP)₃DPPOC (A, where PMIP stands for 1-phenyl-3-methyl-4-isobutyryl-5-pyrazolone) were synthesized. DPPOC has a suitable lowest triplet energy level (24,691 cm^?1) for the sensitization of Tb(III) (⁵D₄: 20,400 cm^?1) and a significantly higher thermal stability (glass transition temperature 137 °C) compared with the familiar ligand triphenylphosphine oxide (TPPO). Experiments revealed that the emission layer of the Tb(PMIP)₃DPPOC film could be prepared by vacuum co-deposition of the complex Tb(PMIP)₃(H₂O)₂ (B) and DPPOC (molar ratio = 1:1). The electroluminescent (EL) device ITO/N,N′-diphenyl-N,N′-bis(1-naphthyl)-1,1′-diphenyl-4,4′-diamine (NPB; 10 nm)/Tb(PMIP)₃ (20 nm)/co-deposited Tb(PMIP)₃DPPOC (30 nm)/2,9-dimethyl-4,7-diphenyl-1,10-phenanthroline (BCP; 10 nm)/tris(8-hydroxyquinoline) (AlQ; 20 nm)/Mg_0.9Ag_0.1 (200 nm)/Ag (80 nm) exhibited pure emission from terbium ions, even at the highest current density. The highest efficiency obtained was 16.1 lm W^?1, 36.0 cd A^?1 at 6 V. At a practical brightness of 119 cd m^?2 (11 V) the efficiency remained above 4.5 lm W^?1, 15.7 cd A^?1. These values are a significant improvement over the previously reported Tb(PMIP)₃(TPPO)₂ (C).     

Computer-aided transistor design, characterization, and optimization

A systematic and general method of computing ac and dc characteristics of double-diffused junction transistors using major process parameters such as dimensions of the device, surface concentration, junction depth, diffusion time, temperature, and diffusion coefficient as a function of temperature and impurity concentration is described. These parameters can be checked during the process and, therefore, can aid the process control problem by predicting the expected values of junction depth and sheet resistivity. If the specified control parameters are met during the fabrication, the ac and dc characteristics of the device will be realized. The time and/or frequency response of a circuit can be computed using the ac and dc characteristics of the diffused devices of the circuit on the basis of a distributed or an equivalent lumped model. The measurement of important ac parameters on the basis of these models has also been simulated on the computer, thus aiding the characterization problem of the device in the integrated circuit environment. Also, the switching speed of a loaded logic net can be computed and optimized by trading off interacting parameters and relating them back to the original diffusion process parameters and dimensions of the components. Finally, experimental verification of the computed results has been accomplished and found to be satisfactory.     

New highly efficient polarization converters based on hybridsupermodes

Mode coupling in strip waveguides can lead to the occurrence of hybrid supermodes. These supermodes offer the opportunity to develop highly efficient polarization converters even in isotropic materials as InP or GaAs. We present the theoretical background for the occurrence of hybrid supermodes and offer concrete design proposals for new polarization converters     

基于改进粒子群算法的无线传感器网络覆盖优化

为了解决粒子群算法的无线传感器网络覆盖方法存在的容易出现局部收敛的问题,提出基于改进粒子群的无线传感器网络覆盖优化方法。分析基本粒子群算法进行无线传感器网络覆盖优化的过程,找出其存在的局部收敛问题,通过采用拟万有引力和库仑力两种拟物方案,在粒子速度进化过程中融入拟物力,对基本粒子群算法的速度修正过程实施优化,避免粒子群算法出现局部收敛问题,降低重复覆盖率,完成无线传感器网络覆盖优化。实验结果表明,改进粒子群算法具有更快的收敛效率,对无线传感网络的覆盖优化效果更好。