档案信息数字化问题刍议

档案作为一种原生的信息资源,其重要性正日益凸显出来。随着信息技术的高速发展和推广应用,档案信息数字化建设逐渐的提上了日程,给档案工作带来了新的契机。因此档案工作者必须更新观念,改变传统的工作模式,掌握信息技术,更好的为档案工作服务,使档案工作向着信息数字化的方向逐步迈进。     

档案信息数字化问题刍议

档案作为一种原生的信息资源,其重要性正日益凸显出来。随着信息技术的高速发展和推广应用,档案信息数字化建设逐渐的提上了日程,给档案工作带来了新的契机。因此档案工作者必须更新观念,改变传统的工作模式,掌握信息技术,更好的为档案工作服务,使档案工作向着信息数字化的方向逐步迈进。     

多Agent群体行为中的扩散趋同综述

为了研究复杂系统及复杂性科学问题,人们提出多Agent模型进行建模和分析.多Agent的群体行为是复杂系统研究所必须解决的问题,而其中的扩散趋同更是相关领域的研究热点.文中首先介绍多Agent群体行为中的扩散趋同现象,然后根据Agent扩散趋同传递的方式、Agent的扩散趋同能力的分布情况和Agent扩散趋同所感知的范围,将相关研究成果中的扩散趋同机制分为3个方面:层次结构性扩散趋同与群集性扩散趋同、平滑扩散趋同与非平滑扩散趋同、邻域扩散趋同与全局扩散趋同.文中对每种模型的特点进行论述和比较分析,最后指出下一步的研究方向.     

Review of the Year,Part II: 2001: A game of two halves

In Part 1 of this Review, we got as far as the middle of the year. The economic climate was driving a lot of discussion and technology usage seemed to take second place to what was economically viable. The major event of this year took place in September, but we still have a little way to go before we get there. And, don’t forget to check out our predictions for 2002 as well. But enough of the doom and gloom, let’s kick off Part II by revisiting some moments the world’s largest software firm would rather forget…     

Review of the Year,Part I: 2001: A game of two halves

Here at Network Security, we chewed over the events of the year as they happened. We've reviewed them, added analysis and made assertions to challenge and inform our readers. But, now is the time to summarize them in our customary cohesive and well-heeled manner — and we have come unstuck. The truth is, 2001 is like two different years. The events of 11 September have cast a new light on both future and past, causing any analysis to become disjointed, schizophrenic. Even so, here is our rundown on the year that was. Part I takes us up to the summer. In Part II, in January’s issue, we’ll take you through to the end of the year, and wheel out our crystal ball for some predictions for 2002.     

Influencing versus Informing Design, Part 1: A Gap Analysis

The collaboration of cognitive systems engineers with systems engineers is motivated by the goal of creating human-centered systems. However, there can be a gap in this collaboration. In presentations at professional meetings about cognitive systems engineering projects, we often hear that one or another method of cognitive task analysis was employed in order to inform design. But what software developers need is designs. This is the first of two essays about the gap between the products of cognitive task analysis and the needs of the software engineers. We discuss a success story of cognitive systems engineering for a large-scale system, a project that coped with the practical constraints of time pressure and the challenge of designing for an envisioned world when system elements could not be fully specified in advance. This project relied on a particular product from cognitive task analysis, the abstraction-decomposition matrix, that speaks in a language that corresponds with the needs and goals of the software designers.     

Staff Smart, Part 1: Motivation

If you're a manager, for the most part, you can only be as capable and productive as your staff. It thus behooves you to develop skills to make your staff as capable and as productive as they can reasonably be. How do you do this? It depends to a large extent on your skills in recruiting, your artistry in motivating, and your knack in delegating.     

一种基于Peer-to-Peer的分布式文件共享框架

主要探讨了在基于非集中式Peer to Peer网络中实现分布式文件共享和传输管理需要考虑的主要因素，给出了基于Gnutella框架的改进之处以及实现细节，并提出了以通信自相似性和拓扑幂律分布相结合的特性模型。     

一种非DHT查找方式的结构化P2P文件共享模型

普遍认为在结构化P2P协议中实现能力感知会增加网络开销.提出一种能力感知结构化P2P协议——HeteroChord,HeteroChord在新加入结点的路由表建立算法与更新算法中实现能力感知,能力感知速度快,在动态环境下,HeteroChord具有比Chord更小的维护开销.针对HeteroPastry文件索引双向复制开销大以及不能遍历强结点的缺点,以HeteroChord协议为基础建立一种非DHT查找方式的文件共享模型——NHFS,NHFS将超级结点简单首尾相连形成super leaf set,并采用选择性单向复制把文件索引复制到超级结点,使查询仅在超级结点中进行.super leaf set使查询可以方便遍历超级结点,且选择性单向复制文件索引产生的网络开销远小于双向复制文件索引产生的网络开销,相对HeteroPastry而言,NHFS文件共享模型更合理.     

基于兴趣特征向量的端对端仿真学习社区研究

为了正确分类远程教育环境中具有相同学习兴趣的学习者,提出了一个基于学习者兴趣特征向量的端对端自适应仿真学习社区构建算法.算法着眼于一个开放的分布式仿真学习环境,在一个端对端的系统框架下,赋予每个学习者一个学习兴趣向量,并通过模拟学习者之间相互推荐学习资料来对学习者进行分组.仿真实验结果表明:经过一段学习者之间关系调整的时间,算法能显著提高学习资源推荐的正确率,提高学习者的满意度.所以,算法很合适应用于远程学习社区的构建.     

浅谈“十五”期间我国仪器仪表工业的发展

文章论述了仪器仪表工业在国民经济中的战略地位，作用：提出了“十五”期间采用自主创新，超前发展及突出重点等发展；建议政府制定政策扶持仪器仪表工业的发展。     

S-Chord：一种基于分组的P2P系统研究

Chord是结构化基于DHT的典型算法,但是由于各节点性能的不一致性。使得部分节点负载过大,节点的频繁加入和退出使得系统的路由表要频繁的更新,严重影响系统的性能,而且整体的DHT机制也不能保证节点的安全性,文章提出了一种基于分组的S-Chord系统,将分组内指定一个manager节点并且引入了中间节点,减少路由表更新的信息量,有效的解决了系统效率和安全性问题。     

Multiscale Computational Homogenization: Review and Proposal of a New Enhanced-First-Order Method

The continuous increase of computational capacity has encouraged the extensive use of multiscale techniques to simulate the material behaviour on several fields of knowledge. In solid mechanics, the multiscale approaches which consider the macro-scale deformation gradient to obtain the homogenized material behaviour from the micro-scale are called first-order computational homogenization. Following this idea, the second-order FE2 methods incorporate high-order gradients to improve the simulation accuracy. However, to capture the full advantages of these high-order framework the classical boundary value problem (BVP) at the macro-scale must be upgraded to high-order level, which complicates their numerical solution. With the purpose of obtaining the best of both methods i.e. first-order and second-order, in this work an enhanced-first-order computational homogenization is presented. The proposed approach preserves a classical BVP at the macro-scale level but taking into account the high-order gradient of the macro-scale in the micro-scale solution. The developed numerical examples show how the proposed method obtains the expected stress distribution at the micro-scale for states of structural bending loads. Nevertheless, the macro-scale results achieved are the same than the ones obtained with a first-order framework because both approaches share the same macro-scale BVP.     

Collective plume tracing: A minimal information approach to collective control

A team of simple robots are used to trace a chemical plume to its source in order to find buried landmines. The goal of this paper is to analyze and design ‘emergent’ behaviors to enable the team of simple robots to perform plume tracing with the assistance of information theory. The first step in the design process is to define a fundamental trade‐off for collective systems between processing, memory, and communications for each robot in order to execute the desired collective behaviors. The baseline problem is to determine the minimum values for processing, memory, and communications simultaneously. This will enable the designer to determine the required information flow and how effectively the information resources are being utilized in collective systems. The solution to this baseline problem is an 8‐bit processor, no memory, and three words to communicate. The details of this solution are described in this paper. The second step is to extend the previous kinematic solution to a more general Hamiltonian‐based solution to develop a Fisher Information Equivalency. The Fisher Information Equivalency leads directly to necessary and sufficient conditions for stability and control of nonlinear collective systems via physical and information exergy flows. In particular, the creation of a ‘virtual/information potential’ by the team of robots via the decentralized distributed networked sensors produces a direct relationship between proportional feedback control, stored exergy in the system, and Fisher Information. This nonlinear stability formulation through Fisher Information directly provides an optimization problem to ‘tune’ the performance of the team of robots as a function of required information resources. Copyright © 2009 John Wiley & Sons, Ltd.     

Review of options for structural design sensitivity analysis. Part 1: Linear systems

The paper reviews options for structural design sensitivity analysis, including global finite differences, continuum derivatives, discrete derivatives, and computational or automated differentiation. The objective is to put these different approaches to design sensitivity analysis in the context of accuracy and consistency, computational cost, and implementation options and effort. Linear static analysis and transient dynamic analysis are reviewed. In a separate appendix, special attention is paid to the semi-analytical method. A future paper will address design sensitivity analysis in nonlinear structural problems.     

Meta-firewall: A sixth generation firewall — Part 1

Terminology in the firewall area is still confusing. Proxies, packet filters, ‘stateful’ filters, hybrid approaches, fifth generation firewalls and many more rule the market, and thus rule the user's mind of what is good and what is bad. But few people (1) have thought about the relationships between all those technologies, how they can interact, and how they can be integrated to increase security on a perimeter network to a maximum. Let us call this approach a ‘meta-firewall’, designed to provide maximum security for dedicated purposes. All of the issues involved in planning for a solution for any network cannot be discussed, but it is an approach to a new way of thinking what can be done with firewalls and the like. The first part of this two-part article begins to build the layers of security in a firewall for an imaginary company.     

Software Construction, Part 1

This is the first installment of a software engineering glossary of software construction terminology.     

Tracing Hackers: Part 1

In the computer security arena, every now and then, a vulnerability comes along causing a significant impact. The impact of a vulnerability is based on factors such as popularity of the vulnerable platform and the ease of exploitation of the vulnerability. Lots of research gets done on a vulnerability, beginning from its origin to the various permutations and combinations of exploit code that come out subsequently. In recent years, we have seen self-propagating exploit code (in other words, worms) becoming quite popular.