一种集成微力检测的压电式微夹钳

针对微装配任务设计了一种双悬臂梁结构的压电双晶片微夹钳,该微夹钳由两个压电双晶片驱动．建立了压电双晶片的复合梁模型,并对它的微位移—电压特性、夹持力—应变特性进行了数学分析．通过检测悬臂梁根部的应变信号实现对微夹钳夹持力的检测．实验证明该微夹钳工作可靠,能够满足微装配机器人装配任务的要求．     

毫米级全方位移动微型装配机器人设计、运动学分析与控制

介绍了一种用于微型工厂的毫米级移动微装配机器人,其具有独特的全方位运动结构．微机器人由4个直径3 mm的电磁微马达驱动,并装备有一对微型夹钳．通过分析运动学矩阵的秩,证明了微机器人的全方位特性,并建立了微夹钳的运动学方程．设计了基于计算机视觉的微机器人控制系统,给出了微机器人定位和驱动方法．实验证明了微机器人的负载能力、机动性以及控制系统的有效性．     

静电梳微振子结构和特性研究

较系统地研究了静电梳驱动微振子的结构和工作原理，导出了微振子的谐振频率、品质因子及跨导等参数，以及相应的力学和电学模型，并研究了空气粘滞效应对品质因子的影响，在此基础上，设计出几种不同尺寸，不同形状的微型谐振子结构，并用表面微机械加工方法成功地制成了能横向振动的静电梳微振子，实测得到的谐振频率在７．５￣９．０ｋＨｚ范围内，在空气中品质因子为１００左右，与理论计算能较好符合。     

微膜尺寸与吸附物对微膜生化传感器动态特性的影响

以微膜生化传感器为研究对象,利用ADINA软件进行模态分析,获得了微膜生化传感器在液态介质影响下的固有频率,分析了微膜结构尺寸和吸附物对传感器动态性能的影响。研究表明：微膜生化传感器的固有频率随着微膜厚度的增大而增大,随着微膜半径的增大而减小。吸附物质量使传感器的固有频率降低,吸附物的吸附位置也对传感器的固有频率产生影响。     

一种无线网络环境中的微支付协议

基于R.Rivest和A．Shamir提出的微支付协议PayWord的一个改进方案NMP，为无线网络环境中的小额交易设计了一种新的无线微支付协议WMP(Wireless Micropayment Protocol)。WMP协议在充分考虑安全性、公平性、不可否认性以及匿名性的基础上，针对目前无线微支付环境中带宽和客户端计算能力较低的问题，尽可能地优化了协议执行过程中的通信代价和客户端的计算量，具有较好的性能和较高的运行效率。     

一种新型管道内微机器人的研究

本文描述了一种微管道机器人的结构与控制,分析 了这种微管道机器人的移动原理,该机器人借用仿生学原理,结构独特、简单、新颖,运行 速度快,能方便地实现前进和后退,可以在各种形状的弯管内运行．具有自学习功能,实现 了智能控制．该机器人的直径为8mm,最小长度为16mm,最高运动速度为40mm/s,牵引力大于 0.5N．该机器人可用于核电站航天飞机等其他特殊领域的微小型管道的检查,维护．     

陶瓷厚膜微压变送器的研制

阐述了利用超薄微压陶瓷弹性体和厚膜技术及特殊的密封技术研制的一种新型陶瓷厚膜微压变送器。这种变送器具有坚固，抗腐蚀和磨损以及抗冲击和振动性能，且具有宽温范围和高性能价格比，其应用将会在微压检测方面起到重要作用。     

用于微器件装配的微操作系统

微器件装配技术是微机械的关键技术之一,本文从微 器件装配系统的特性和功能出发,提出了一套用于微装配的微操作系统设计方案,并对系统 各个组成部分进行分析,介绍了系统实现的方法．     

硅微压电超声换能器的设计与制作

介绍了一种用ZnO薄膜作为压电层的硅微压电式超声换能器(PMUT).该硅微压电换能器的振动基膜采用LPCVD制作的氮化硅薄膜和PECVD制作的二氧化硅形成的复合振动膜结构.文中运用有限元方法对该硅微压电换能器的结构进行了模拟和计算,并进行了预应力对硅微换能器共振频率的影响的分析.实验测得硅微压电式换能器的共振频率为71.36 kHz.本文还使用该硅微超声换能器在油中进行了初步的共振频率点收发信号的实验,接收实验测得信号峰峰值为9 mV左右,发射实验标准水听器接收信号峰峰值为0.8 mV左右.     

一种新型仿壁虎爬行机器人的粘附阵列设计

分析了壁虎与表面间的微尺度粘附接触作用模型,在此基础上设计了一种具有主动控制能力的仿壁虎微纳米粘附阵列．给出了粘附阵列各设计参数,并介绍了微纳米阵列的加工工艺方法．     

热环境下金属橡胶隔振结构的耗散特性及参数识别

由于金属橡胶的耗散特性对温度非常敏感且显著影响隔振性能,因此,开展热环境下金属橡胶隔振结构的耗散及参数识别研究十分重要.本文设计了一种双层金属橡胶隔振结构,研究了环境温度对该隔振结构耗散特性的影响规律,基于试验数据建立了金属橡胶双层隔振结构的非线性本构模型.首先,在不同温度下对该隔振结构进行了一系列耗散特性试验,绘制了隔振结构在各工况下的耗散特性曲线,计算了隔振结构的耗散系数、耗散能量以及最大变形势能,分析了温度、振幅、频率对金属橡胶双层隔振结构耗散特性的作用规律.然后,使用非线性最小二乘法对隔振结构的参数进行了识别,建立了该金属橡胶隔振结构的非线性泛函本构模型,准确预测了隔振结构在各工况下的耗散特性曲线.     

Construction of Deliberation Structure in E-Mail Communication

We propose a model, called a deliberation structure model , that represents streams of relevant messages in email communication. The deliberation structure model treats e-mail messages that include several topics and uses tree structure, called deliberation trees , that are based on Clark's contribution trees to represent message structure. Deliberation trees are useful to visualize the message structure. A method for constructing the deliberation structure is showed.     

Genetic Threading

The biological function of proteins is dependent, to a large extent, on their native three dimensional conformation. Thus, it is important to know the structure of as many proteins as possible. Since experimental methods for structure determination are very tedious, there is a significant effort to calculate the structure of a protein from its linear sequence. Direct methods of calculating structure from sequence are not available yet. Thus, an indirect approach to predict the conformation of protein, called threading, is discussed. In this approach, known structures are used as constraints, to restrict the search for the native conformation. Threading requires finding good alignments between a sequence and a structure, which is a major computational challenge and a practical bottleneck in applying threading procedures. The Genetic Algorithm paradigm, an efficient search method that is based on evolutionary ideas, is used to perform sequence to structure alignments. A proper representation is discussed in which genetic operators can be effectively implemented. The algorithm performance is tested for a set of six sequence/structure pairs. The effects of changing operators and parameters are explored and analyzed.     

The Role of Visual Perception in Data Visualization

This paper presents a perceptually motivated formal framework for effective visualization of relational data. In this framework, the intended structure of data and the perceptual structure of visualizations are formally and uniformly defined in terms of relations that are induced on data and visual elements by data and visual attributes, respectively. Visual attributes are analyzed and classified from the perceptual point of view and in terms of perceptual relations that they induce on visual elements. The presented framework satisfies a necessary condition for effective data visualizations. This condition is formulated in terms of a structure preserving map between the intended structure of data and the perceptual structure of visualization.     

Color error from an RGB‐stripe pixel structure

Abstract— Most direct‐view color displays have a sub‐pixel structure similar to the RGB‐stripe structure. The video data for R and B are produced on the condition that they are reproduced at the same position as G but they are displayed on the screen with 1/3 of a pixel separation from the corresponding G pixel. This pixel structure thus entails a convergence error of 1/3 of a pixel. The modified s‐CIELAB method was applied to investigate color errors produced by the RGB‐stripe pixel structure. The results show that the pixel structure can degrade the image quality even for a viewing distance where the pixel structure is not visible because the color difference caused by the structure has a low‐frequency component and the human vision can detect it. The same method was applied to the convergence error and it was shown that the necessary convergence accuracy is around 1/4 of a pixel.     

离散事件动态系统的结构

提出对离散事件动态系统的结构及组合规律进行研究的问题, 提出离散事件动态系统结构的定义, 提出子系统的两种组合方式并论证了相关的性能保持条件. 利用系统的结构及组合规律, 可以在建模过程中同时考虑控制需求, 避免常规方法的分析困难和综合复杂性, 大幅度减少系统分析和设计过程的开销, 从而为离散事件动态系统监控理论的应用开拓新的途径.     

Primitives for the manipulation of three-dimensional subdivisions

Algorithms for manipulating three-dimensional cell complexes are seldom implemented due to the lack of a suitable data structure for representing them. Such a data structure is proposed here along with the primitive operations necessary to make it useful. Applications of the structure are also given.     

A novel digital filter structure with minimum roundoff noise

In this paper, a novel structure is derived for efficient implementation of digital filters as well as minimizing the finite word length (FWL) errors. Such a structure is actually an improved version of that reported previously. The performance of this new structure and the famous normalized lattice structure are analyzed by deriving the corresponding expression for the roundoff noise gain. Design examples are presented to illustrate the behavior of the proposed structure and to compare it with some existing ones. It is shown that the proposed structure outperforms the others in terms of minimizing roundoff noise as well as implementation efficiency.     

决策问题结构的形式化研究

运用分形理论研究决策问题结构，对决策问题进行形式化描述，定义其结构函数和结构指数，并将决策问题从定性上分为良好结构、未结构化和纯不良结构。给出了关于决策问题结构的几个定理，讨论了决策问题结构化的测度，提出了决策问题简化的判据。     

Variable structure controller design for linear systems with bounded inputs

This paper studies the design of variable structure systems with saturation inputs. Sliding mode domain, reaching domain, and unescapable reaching domain of linear systems with variable structure are defined and investigated. When the state matrix of the linear system is Hurwitz, the stability of the variable structure systems is proven by using passivity theory. Moreover, variable structure systems with novel nonlinear switching surfaces are proposed for second order systems. Two strategies for designing variable structure control for high order linear systems are also proposed, such as stepby-step variable structure control and moving-surface variable structure control, which were found to guarantee that the reaching condition of the variable structure control is always satisfied. Finally, an illustrative example pertaining to the attitude control of a flexible spacecraft demonstrates the effectiveness of the proposed methods.