LDAP目录服务在PKI/PMI中的应用

轻量级目录访问协议是互联网中一门新技术，它可用来为PKI／PMI提供后台数据支持，优化数据的查询，同时其目录数据的树形结构，也可优化PKI／PMI中资源的管理。该文探讨了LDAP目录服务在PKI／PMI中的应用方案，并且给出了一种采用JNDI技术实现基于Web的LDAP目录服务方案。     

LDAP目录服务在企业PKI／PMI中的应用

PMI提出了一个新的信息保护基础设施,能够与PKI和目录服务紧密地集成,并系统地建立起对认可用户的特定授权．对权限管理进行了系统的定义和描述,完整地提供了授权服务所需过程。对建立在PKI基础上的PMI在企业中建立了授权关系建模．将授权模型及其变更关系在LDAP树的设计中体现,并简要提出了LDAP目录服务在PKI／PMI混合系统中的应用。     

LDAP目录服务在企业PKI/PMI中的应用

PMI提出了一个新的信息保护基础设施,能够与PKI和目录服务紧密地集成,并系统地建立起对认可用户的特定授权,对权限管理进行了系统的定义和描述,完整地提供了授权服务所需过程。对建立在PKI基础上的PMI在企业中建立了授权关系建模,将授权模型及其变更关系在LDAP树的设计中体现,并简要提出了LDAP目录服务在PKI/PMI混合系统中的应用。     

轻量级目录访问协议在证书库中的应用

轻量级目录访问协议(LDAP)是互联网中的一门新技术,目录服务作为数字证书系统、统一认证和授权管理系统的核心基础设施,为公钥数字证书和公钥属性证书提供查询、证书废止列表查询.探讨了LDAP目录服务PKI/PMI中的应用方案,着重论述了如何建立证书库的应用.     

基于PKI和LDAP的全球网格安全系统*

对于高性能分布式计算环境——网格来说,网格安全是非常重要的,网格安全是网格被广泛应用的基础。首先介绍了轻量级目录访问协议LDAP,讨论了PKI基础设施以及LDAP和PKI在全球网格安全系统中的作用,提出了一个基于PKI和LDAP的全球网格安全模型GGSM。     

URP中授权管理系统的设计与实现

PMI是一个新的信息保护基础设施,能够与PKI和目录服务紧密集成.PMI作为一个基础设施,能够系统地建立起对合法用户的特定授权.PMI通过结合授权管理系统和身份认证系统消除了PKI的弱点,提供将PKI集成到商业计算环境的应用模型,而不只是将PKI的应用限制在用户安全解决方案上,因此,基于PMI的授权应用前景很好.文中介绍数字校园及URP(大学资源计划)的概念,分析PMI技术的授权管理模式的特点,重点叙述PMI与PKI,URP应用系统的逻辑关系,并设计与实现URP中的授权管理系统.     

LDAP服务器在PKI中的应用研究

数字证书服务与信息存储服务是PKI服务的基础,LDAP以其自身的固有特性成为认证服务中信息存储服务的首选。文章探讨了LDAP目录服务器的特点,给出了LDAP服务器与数字证书服务器的典型架构模式,以及如何使数字证书服务器与LDAP目录服务器协同的具体方法。     

一种基于PKI的授权访问控制模型

基于PKI的身份认证技术以其较高的安全性和可靠性得到了广泛的认可,而随之而来的授权问题也成为实现应用系统安全重点考虑的问题。为解决基于PKI安全认证后的授权问题,本文提出了一种基于双LDAP目录与RBAC相结合的授权模型,核心部分是角色LDAP目录和授权服务程序。     

URP中授权管理系统的设计与实现

PMI是一个新的信息保护基础设施,能够与PKI和目录服务紧密集成。PMI作为一个基础设施,能够系统地建立起对合法用户的特定授权。PMI通过结合授权管理系统和身份认证系统消除了PKI的弱点,提供将PKI集成到商业计算环境的应用模型,而不只是将PKI的应用限制在用户安全解决方案上,因此,基于PMI的授权应用前景很好。文中介绍数字校园及URP(大学资源计划)的概念,分析PMI技术的授权管理模式的特点,重点叙述PMI与PKI,URP应用系统的逻辑关系,并设计与实现URP中的授权管理系统。     

基于关系数据库的LDAP证书查询服务器的实现

LDAP协议是Internct中用于数据查询访问的重要协议,在PKI基础设施中,LDAP可用于证书和CRL的查询下载,具有广泛而重要的应用。结合了LDAP协议标准和PKI实现的具体要求,提出了一种基于关系数据库的LDAP服务器的实现方式,实现了LDAP的查询操作。     

Only connect: teaching, technology and telesis

Abstract This paper describes an approach to the design of interactive multimedia materials being developed in a European Community project. The developmental process is seen as a dialogue between technologists and teachers. This dialogue is often problematic because of the differences in training, experience and culture between them. Conditions needed for fruitful dialogue are described and the generic model for learning design used in the project is explained.     

European Community policy and the market

Abstract This paper starts with some reflections on the policy considerations and priorities which are shaping European Commission (EC) research programmes. Then it attempts to position the current projects which seek to capitalise on information and communications technologies for learning in relation to these priorities and the apparent realities of the marketplace. It concludes that while there are grounds to be optimistic about the contribution EC programmes can make to the efficiency and standard of education and training, they are still too technology driven.     

一种自适应子融合集成多分类器方法

融合集成方法已经广泛应用在模式识别领域,然而一些基分类器实时性能稳定性较差,导致多分类器融合性能差,针对上述问题本文提出了一种新的基于多分类器的子融合集成分类器系统。该方法考虑在度量层融合层次之上通过对各类基多分类器进行动态选择,票数最多的类别作为融合系统中对特征向量识别的类别,构成一种新的自适应子融合集成分类器方法。实验表明,该方法比传统的分类器以及分类融合方法识别准确率明显更高,具有更好的鲁棒性。     

Avoiding semantic and temporal gaps in developing software intensive systems

Development of software intensive systems (systems) in practice involves a series of self-contained phases for the lifecycle of a system. Semantic and temporal gaps, which occur among phases and among developer disciplines within and across phases, hinder the ongoing development of a system because of the interdependencies among phases and among disciplines. Such gaps are magnified among systems that are developed at different times by different development teams, which may limit reuse of artifacts of systems development and interoperability among the systems. This article discusses such gaps and a systems development process for avoiding them.     

Designing economic np control charts: A programmed simulation approach

This paper presents control charts models and the necessary simulation software for the location of economic values of the control parameters. The simulation program is written in FORTRAN, requires only 10K of main storage, and can run on most mini and micro computers. Two models are presented - one describes the process when it is operating at full capacity and the other when the process is operating under capacity. The models allow the product quality to deteriorate to a further level before an existing out-of-control state is detected, and they can also be used in situations where no prior knowledge exists of the out-of-control causes and the resulting proportion defectives.     

The development of robot art

Going through a few examples of robot artists who are recognized worldwide, we try to analyze the deepest meaning of what is called “robot art” and the related art field definition. We also try to highlight its well-marked borders, such as kinetic sculptures, kinetic art, cyber art, and cyberpunk. A brief excursion into the importance of the context, the message, and its semiotics is also provided, case by case, together with a few hints on the history of this discipline in the light of an artistic perspective. Therefore, the aim of this article is to try to summarize the main characteristics that might classify robot art as a unique and innovative discipline, and to track down some of the principles by which a robotic artifact can or cannot be considered an art piece in terms of social, cultural, and strictly artistic interest. This work was presented in part at the 13th International Symposium on Artificial Life and Robotics, Oita, Japan, January 31–February 2, 2008     

Explanation and prediction: an architecture for default and abductive reasoning

Although there are many arguments that logic is an appropriate tool for artificial intelligence, there has been a perceived problem with the monotonicity of classical logic. This paper elaborates on the idea that reasoning should be viewed as theory formation where logic tells us the consequences of our assumptions. The two activities of predicting what is expected to be true and explaining observations are considered in a simple theory formation framework. Properties of each activity are discussed, along with a number of proposals as to what should be predicted or accepted as reasonable explanations. An architecture is proposed to combine explanation and prediction into one coherent framework. Algorithms used to implement the system as well as examples from a running implementation are given.     

Three Process Perspectives: Organizations, Teams, and People

This paper provides the author's personal views and perspectives on software process improvement. Starting with his first work on technology assessment in IBM over 20 years ago, Watts Humphrey describes the process improvement work he has been directly involved in. This includes the development of the early process assessment methods, the original design of the CMM, and the introduction of the Personal Software Process (PSP)^SM and Team Software Process (TSP){^SM}. In addition to describing the original motivation for this work, the author also reviews many of the problems he and his associates encountered and why they solved them the way they did. He also comments on the outstanding issues and likely directions for future work. Finally, this work has built on the experiences and contributions of many people. Mr. Humphrey only describes work that he was personally involved in and he names many of the key contributors. However, so many people have been involved in this work that a full list of the important participants would be impractical.     

基于复小波噪声方差显著修正的SAR图像去噪

提出了一种基于复小波域统计建模与噪声方差估计显著性修正相结合的合成孔径雷达(Synthetic Aperture Radar,SAR)图像斑点噪声滤波方法。该方法首先通过对数变换将乘性噪声模型转化为加性噪声模型,然后对变换后的图像进行双树复小波变换(Dualtree Complex Wavelet Transform,DCWT),并对复数小波系数的统计分布进行建模。在此先验分布的基础上,通过运用贝叶斯估计方法从含噪系数中恢复原始系数,达到滤除噪声的目的。实验结果表明该方法在去除噪声的同时保留了图像的细节信息,取得了很好的降噪效果。     

How do children do mathematics with LOGO?

Abstract  This paper considers some results of a study designed to investigate the kinds of mathematical activity undertaken by children (aged between 8 and 11) as they learned to program in LOGO. A model of learning modes is proposed, which attempts to describe the ways in which children used and acquired understanding of the programming/mathematical concepts involved. The remainder of the paper is concerned with discussing the validity and limitations of the model, and its implications for further research and curriculum development.