医学图像三维重建模型的剖切与立体视窗剪裁

基于医学图像三维重建是医学图像可视化和医疗放射治疗放射治疗规划的基础，在人体多组织器官的重建及可视化中，为地重建组织的截面形状进行分析，观察内部组织的结构及空间位置，需要对重建模型施以剖切及对外表模型进行立体剪裁，针对医学图像重建的表面几何模型，提出对模型进行剖切及开窗的一种方法，该方法用剖切面或剖切体对重建模型施以剖切，在剖切面上生成边序列及顶点序列，由此边序列和顶点序列生成封闭的边界轮廓，确定各轮廓的包含关系，对封闭轮廓包围面区域进行Delaunay三角部分，得到完整的剖切后的表面模型，模型被剖切或开窗，可以方便地看到内部的组织，便于观察和诊断。     

基于椭圆曲线密码体制的可认证的密钥协商设计与分析

椭圆曲线密码体制以其密钥短、安全强度高、速度快等优越性被广泛用于进行构建数字签名和用户身份认证方案.同样,它也可以用来构建密钥交换协议.Diffie-Hellman密钥协商协议对来自中间人的攻击是脆弱的.基于椭圆曲线离散对数难解性, 利用椭圆曲线密码体制的数字签名方案,提出了基于身份认证的密钥协商协议.该协议提供身份认证、密钥确认、完美前向安全性, 并能够防止中间人攻击.     

一类简单闭域的包含测试算法设计

自由曲面的高斯图计算中,需要对由抛物线和直线段组成的闭域进行包含检测来判断该闭域是否为最小闭域,抛物线段由逼近折线多边形表示且单调。基于点与简单闭域的拓扑关系,重新定义了“穿越边界”,设计了点与简单闭域关系判断的算法。该算法通过检测穿越闭域边界次数的奇偶性来判断点与闭域的位置关系;其中对射线与抛物线相交的处理大大减少了判断次数。可以证明算法的时间复杂度仅为o(n);实验表明,该算法简单有效可靠。     

实时监测系统中SNMP报文分析算法的实现

简单网络管理协议帮助网络管理员实现对基于TCP/IP网络的分布式系统的有效管理。管理员在本地计算机上(通常是一个工作站)使用“取—存”模式完成对代理的各种控制,而代理通过对SNMP报文的分析将通信原语转换成等价的在本地数据结构上的操作。本文从SNMP基本体系结构入手,提出了一种基于VisualC 的实时监测系统中SNMP报文分析算法的实现。     

Assistant force compensation for hand movement of patients by using exogenous signals and/or neurophysiological signals

Because functional diseases of the brain can cause disabilities related to human movement control, a compensation method was developed for improving the performance of hand movements. The compensation for human hand movements can be carried out by adding an assistant force that is generated from artificial equipment attached to a human arm. From the experiment on visual target tracking, it was found that the tracking trajectory was adequately represented by a dynamic model of the motion of an articulated industrial robot arm, and the different abilities for movement control among healthy people and patients were classified by different model parameters as position loop gain, velocity loop gain, and response delay. Dynamic force compensation was approached by considering the different control features of the patients. The effectiveness of the proposed compensation method was verified in a simulation study on an actual industrial robot arm. A human-machine interface, e.g., a brain-computer interface (BCI), for realizing the control of artificial equipment to compensate for human hand movements is also presented and discussed.     

Finite‐time formation control of multiple nonholonomic mobile robots

This paper considers finite‐time formation control problem for a group of nonholonomic mobile robots. The desired formation trajectory is represented by a virtual dynamic leader whose states are available to only a subset of the followers and the followers have only local interaction. First of all, a continuous distributed finite‐time observer is proposed for each follower to estimate the leader's states in a finite time. Then, a continuous distributed cooperative finite‐time tracking control law is designed for each mobile robot. Rigorous proof shows that the group of mobile robots converge to the desired geometric formation pattern in finite time. At the same time, all the robots can track the desired formation trajectory in finite time. Simulation example illustrates the effectiveness of our method. Copyright © 2012 John Wiley & Sons, Ltd.     

智能小区单元门密码控制系统的研究与实现

介绍小区智能管理系统中的密码控制模块的设计过程，该模块能完成数据处理和网络通信等功能，具有良好的可移植性，能根据需要进行功能扩展。要求既能独立工作，又能作为整个系统工程的一部分，还要能扩展密码系统的通信接口与主机进行数据传输。系统采用了单片机来实现。     

1~26.5GHz GaAs PIN单刀单掷开关单片

采用GaAs PIN二极管,完成1~26.5 GHz的单刀单掷开关单片的设计、制作。SPST开关单片带内插损小于0.5 dB,驻波优于1.1,隔离度大于27 dB,在10~26.5 GHz,隔离度大于37 dB。开关单片采用MOCVD生长的GaAs纵向PIN二极管材料结构,76 mm GaAs圆片工艺加工制作。     

Automatic generation of boundary conditions using demons nonrigid image registration for use in 3-D modality-independent elastography

Modality-independent elastography (MIE) is a method of elastography that reconstructs the elastic properties of tissue using images acquired under different loading conditions and a biomechanical model. Boundary conditions are a critical input to the algorithm and are often determined by time-consuming point correspondence methods requiring manual user input. This study presents a novel method of automatically generating boundary conditions by nonrigidly registering two image sets with a demons diffusion-based registration algorithm. The use of this method was successfully performed in silico using magnetic resonance and X-ray-computed tomography image data with known boundary conditions. These preliminary results produced boundary conditions with an accuracy of up to 80% compared to the known conditions. Demons-based boundary conditions were utilized within a 3-D MIE reconstruction to determine an elasticity contrast ratio between tumor and normal tissue. Two phantom experiments were then conducted to further test the accuracy of the demons boundary conditions and the MIE reconstruction arising from the use of these conditions. Preliminary results show a reasonable characterization of the material properties on this first attempt and a significant improvement in the automation level and viability of the method.     

High‐Performance Cathode Based on Self‐Templated 3D Porous Microcrystalline Carbon with Improved Anion Adsorption and Intercalation

Dual‐ion batteries (DIBs) have attracted much attention due to their advantages of low cost and especially environmental friendliness. However, the capacities of most DIBs are still unsatisfied (≈100 mAh g^?1) ascribed to the limited capacity of anions intercalation for conventional graphite cathode. In this study, 3D porous microcrystalline carbon (3D‐PMC) was designed and synthesized via a self‐templated growth approach, and when used as cathode for a DIB, it allows both intercalation and adsorption of anions. The microcrystalline carbon is beneficial to obtain capacity originated from anions intercalation, and the 3D porous structure with a certain surface area contributes to anions adsorption capacity. With the synergistic effect, this 3D‐PMC is utilized as cathode and tin as anode for a sodium‐based DIB, which has a high capacity of 168.0 mAh g^?1 at 0.3 A g^?1, among the best values of reported DIBs so far. This cell also exhibits long‐term cycling stability with a capacity retention of ≈70% after 2000 cycles at a high current rate of 1 A g^?1. It is believed that this work will provide a strategy to develop high‐performance cathode materials for DIBs.