基于CPK的IKE协议的改进

本文在简要介绍和分析评述IPsec协议的基础上,基于CPK系统提出了对IPsec协议的改进,并对改进的协议利用逻辑化方法作了详细地安全性分析,指出了改进的协议在安全性和效率等方面所具有的优势,同时对应用环境作了说明。     

鉴别协议综述

对鉴别协议的演进发展过程进行了详细的介绍,重点对比分析了目前流行的几种鉴别协议的优缺点,并对目前鉴别协议的发展作了归纳总结.     

对Kerberos协议的攻击及对策研究

Kerberos协议是当今最重要的实用认证协议,但是它也存在着一些局限性和缺陷,文章主要分析了Kerberos协议的两种最重要的攻击：口令攻击和重放攻击,以Windows2000环境下对Kerberos协议进行的攻击为例进行了具体分析。并且把对Keerteros的各种改进方案作了一个全面的分析和总结,把各种方法作了一个对比,找出各种方法的优缺点,这将对以后Kerberos协议更完美的改进起参考作用。     

RIP路由协议及其漏洞攻击防范

本文对RIP协议的基本工作原理、RIP协议的特点,RIP协议的不足之处等基本理论作了科学的阐述。在此基础上指出了边界网关协议存在的缺陷,并对可能存在的漏洞攻击及其防范措施进行了分析。     

基于包交换网络的多媒体通信协议H.323

本文对Ｈ．３２３ 协议的发展历史,组成部分及其作用,相关协议及发展作了简要介绍     

PLC与支持ModBus协议的DCS系统的综合

本文介绍了PLC和DCS的综合技术,对ModBus协议的技术要点和具体的规定作了比较详细的阐述,最后还就PLC和基于MODBUS协议的DCS结合的实现方法作了说明.     

基于IEEE802.15.4的Ad hoc网络路由协议研究

Adhoc网络是一个自组织、动态拓扑变化的网络。由于具有低成本、低功耗的特点,基于IEEE802.15.4的Adhoc网络将得到广泛的应用。文章在分析AODV协议的基础上,提出了适合基于IEEE802.15.4的Adhoc网络的M-AODV协议。并在NS-2中对该协议作了仿真,在性能上和AODV协议作了比较。     

一种安全协议的安全性分析及攻击研究

针对Web安全协议SSL的握手协议部分进行了详尽的阐述，对其安全性作了一定的分析，给出了理论上存在的三个协议漏洞的详尽描述，并且经过测试验证，指出了SSL协议存在***模式漏洞。     

基于时延Petri网的密码协议分析及性能评估

形式化分析方法由于其精炼、简洁和无二义性逐步成为分析密码协议的一条可靠和准确的途径，但是密码协议的形式化分析研究目前还不够深入，针对这一现状，该文提出用时延Petri网来表示和分析密码协议。该模型不但能够反映协议的静态和动态的特性，而且能够对密码协议进行时间、空间上的性能评估。作为实例，文章对MSR无线协议作了详细的形式分析和性能评估。最后，与其它形式化分析密码协议的方法作了比较。     

因特网密钥交换协议的应用研究

介绍IPSec协议,包括IKE协议的安全体系结构、安全策略和IKE协议的不足,重点研究了主模式下预共享密钥认证-仅支持固定IP用户的不足,对协议作了相应改进以支持动态IP。     

Soap bubbles. 1

I consider the chemistry, physics, and computer graphics of soap bubbles. I focus on the physics of soap films, which are, after all, what bubbles are made of. I see what happens when soap dissolves in water and discuss some surprising properties of soap films     

A robust device for large-scale monitoring of bar soap usage in free-living conditions

This work reports the development and evaluation of a robust and easily deployable soap use logging device. The waterproof device contains motion and sound sensors and can be fully embedded in commercial bar soap. At rest, the device is in a low-power mode and the recording of data is triggered by vibrations measured by a tilt switch. Monitoring soap usage is used to support behaviour change interventions, with the aim to reduce contact diseases. Following the algorithm development under laboratory conditions, we evaluate the performance of the logging device under free-living conditions in 58 low-income households in India. In addition to the measurement by logger soaps, washing activity was recorded by observers. These data allow us to quantify the error of soap use detection. Further, the study data are used to train and evaluate an algorithm for the discrimination of soap use associated with hand and body wash. The results show that the soap logger provides an unobtrusive and objective measure of free-living soap usage. The analysis of the activity features reveals a novel hygienic habit, which is important information for the design of bespoke interventions.     

Giant soap bubble creation model

We present a simple and real‐time technique for animating giant realistic looking soap bubbles. Unlike small spherical soap bubbles, giant soap bubbles stretch significantly and undergo globally varying and locally consistent deformations because of time‐varying surface tensions. For physically plausible surface tensions, we introduce and combine a variable‐length mass spring system and Gibbs elasticity and Marangoni elasticity. Using a proposed framework, we deform our models because of general forces from surface tensions, winds, and excessive pressures. Our framework effectively generates a physically plausible animation of giant soap bubbles, differing in shape according to the user's design; generates capillary waves and vibrations while floating in the air; and shows vivid iridescent colors corresponding to the deformations, all of which have been difficult to achieve using previous soap bubble animation methods. Copyright © 2015 John Wiley & Sons, Ltd.     

基于J2ME平台的SOAP协议研究与应用

本文对于在J2ME平台下,利用XML解析器开发SOAP协议的基本方法进行了研究,介绍了J2ME平台和SOAP协议,其中重点探讨了XML的开发,提出了一种利用XML解析器在J2ME平台上实现SOAP协议的方法,具有一定的推广价值。     

Structural optimization and form finding of light weight structures

There exist three different lines of computational form finding methods: (i) simulation of hanging models, (ii) numerical simulation of soap films, and (iii) structural shape optimization. The aim of the present paper is to show their differences and common aspects when applied to the special task of maximizing stiffness. The inverse problem of simulation of soap films is formulated in more detail on the basis of differential geometry. The effect of internal pressure is discussed. Several illustrative examples are given.     

Use of structural analogy in generation of smooth surfaces for engineering purposes

The use of the minimization of surface integrals of functions of the mean and Gaussian curvature to obtain smooth surfaces that satisfy given boundary and other conditions is discussed. A structural analogy based on the bending theory of shells is introduced to enable the designer to predict the effect of changing parameters in the integrals to be minimized. Surfaces of zero mean curvature (minimal or soap film surfaces), surfaces of constant mean curvature (inflated soap films, including the sphere) and the elastica (in two dimensions) are all special cases of the theory.     

Soap film analogy for anisotropically stretched membranes and cable nets

Analogical physical models are a preferred technique to intuitively grasp complex engineering problems. It is well-known that the equilibrium minimal-surface configuration of membranes under equibiaxial tension can be visually represented by the surface of a soap film under equivalent boundary conditions, but this analogy fails when the stress state is not uniform equibiaxial. We extend to this situation the analogy with soap films. The equilibrium state of an orthotropically tensioned membrane is found by geometrically stretching the shape of a soap film, in a precise manner depending upon the applied state of stress. The procedure is easily done by elaborating digital pictures. The method is mathematically justified under the kinematic hypotheses of small strains and large rotations, and further verified in a parametric design environment. It can also provide an insight into the equilibrium configuration of cable-nets, when the stresses in the warp and weft directions are considerably different. Furthermore, this visualization favors implementing transformable shapes for membranes or orthogonal cable nets, as a consequence of a modification of the ratio of the principal stress components.     

Animation of Soap Bubble Dynamics, Cluster Formation and Collision

What is happening when a soap bubble floats on the air? How do bubbles coalesce to form beautiful three‐dimensional clusters? The physical‐based model and animation described herein provide the answers. This paper deals with a complete computer simulation of soap bubbles from a dynamic perspective, which should prove to be of great interest to physicists and mathematicians. We discuss the dynamic formation of irregular bubble clusters and how to animate bubbles. The resulting model takes into account surface tension, film elasticity, and shape variations due to gravity and external wind forces.     

Minimal Surfaces and Architecture: New Forms

Michele Emmer discusses the relations between soap films, arts, mathematics, visual arts, architecture with very recent examples. It’s because I don’t do anything, I chatter a lot, you see, it’s already a month that I’ve got into the habit of talking a lot, sitting for days on end in a corner with my brain chasing after fancies. It is perhaps something serious? No, it’s nothing serious. They are soap bubbles, pure chimeras that attract my imagination. Fedor Dostoevsky, Crime and Punishment      

基于SPH算法的钢球高速撞击肥皂数值仿真

运用光滑粒子流体动力学分析方法,对钢球高速侵彻肥皂靶标进行了数值仿真分析。建立了钢球与肥皂高速撞击数值计算模型,运用侵蚀接触算法,求解了高速钢球侵彻肥皂的动力响应时间历程,获取了钢球侵彻肥皂靶标的侵彻深度与投射物速度关系图和瞬态Von—Mises等效应力云图,分析了高速碰撞过程及碰撞过程中空腔的形成和变化情况,并与实验结果及Lagrange数值仿真结果对照,计算结果具有良好精度,表明运用SPH方法能够较好地描述高速撞击现象。文中的研究表明,SPH技术是开展创伤弹道研究的有效手段。