一种基于票据的单点登录协议设计与实现

随着企业信息化建设的发展,企业信息应用系统的种类、数量越来越多,建立统一的身份认证管理机制,用户只需向身份认证中心提供一次身份信息,便可安全、平滑地访问不同应用系统,即实现单点登录,成为企业信息化建设的重要内容。根据当前企业信息应用系统已具有大量历史遗留帐号的实际情况,本文给出了一种基于票据的单点登录协议,对传统的基于票据的单点登录协议必须依赖全局统一用户身份标识的局限性进行改进,通过该协议能够简单、安全地实现对具有大量历史遗留帐号的应用系统的单点登录集成。     

企业信息门户单点登录系统的设计与实现

本文介绍了一个企业信息门户中单点登录系统的设计与实现。系统实现了一个基于Java EE架构的结合凭证加密和Web Services的单点登录系统,对门户用户进行统一认证和访问控制。论文详细阐述了该系统的总体结构、设计思想、工作原理和具体实现方案,目前系统已在部分省市的广电行业信息门户平台中得到了良好的应用。     

基于SAML改进的单点登录模型研究

针对安全断言标记语言(SAML)的不足,提出了基于站群的会话有效期的概念,设计了主题在线反查协议、定点注销协议和重复登录限制办法,解决了跨域单点登录问题,给出了数据同步策略,实现了源站点和各目标站点之间的松耦合关系,支持可分可合式的系统集成,便于集成历史遗留系统。基于该方案架构的系统已经在我国某大型国有银行中被推广使用,应用结果表明,降低了系统管理成本及用户操作复杂度,提高了生产效率和安全性,满足了企业需要。     

结合Cookie与票据共享的单点登录方案

通过分析现有单点登录模型中存在的不足,针对多个业务应用系统之间的身份认证问题,提出了一种结合Cookie与票据共享的单点登录方案。该方案通过共享票据信息,实现多个业务应用系统之间的单点登录和统一认证,研究表明,该方案具有简单、实用的特点,能够实现多个业务应用系统之间的单点登录和安全认证。     

基于统一用户管理的办公业务资源系统集成

随着办公业务系统的广泛使用,各种支撑办公业务系统应用的用户数量不断增加,但用户信息存在重复记录且不统一的情况,以及需多处登录、跨系统流程无法正常流转等问题越来越突出。文中提出了一种基于统一用户授权管理的办公业务支撑系统的集成方案,目的在于将办公业务系统支撑的账号管理、认证管理和升级整合为集中统一的安全支撑体系。通过对身份认证与分布授权、单点登录、统一用户、数据同步和资源管理等技术的整合,实现了统一的用户管理和维护,对多个Web应用只提供一个登陆窗口即可完成对多个应用的访问,并提供统一的认证源;对于集成在单点登录中的应用系统,可以对应用系统的资源进行角色管理,划分权限。     

基于票据的跨域单点登录

针对单点登录中的跨域身份认证问题,提出了一种基于票据的解决方案,以地址重定向的方式传递加密用户登录信息,异域应用系统获取用户信息并提供数据操作服务。使用随机数字生成票据,并作为生成传统加密算法会话密钥的参数,采用现代加密算法实现异域系统之间的互信并安全传递票据,异域应用系统根据票据产生会话密钥,加密并传输用户登录信息,每次会话产生新的密钥。通过对票据产生和传输以及密钥的安全性分析,可以实现跨域单点登录的功能并保证身份认证安全可信。     

基于Portal的企业门户单点登录和应用集成研究

随着信息化的发展,企业信息系统应用增多,用户访问信息系统需多次登录,记住多个口令,影响了工作效率。本文介绍了基于Portal的企业门户单点登录,提出了一种单点登录和应用集成设计方案,实现了企业门户系统与多个信息系统的单点登录和应用集成,用户只需登录门户系统即可访问任何一个授权的应用系统。     

基于可变Cookie的跨域单点登录

针对单点登录中的跨域身份认证问题,提出了一种基于可变Cookie的方案解决跨域单点登录,使用随机数字生成票据,并作为传统加密算法的会话密钥对客户端的Cookie进行加密,采用现代加密算法在异域系统之间安全传递票据,每次认证产生新的票据并更新异域应用系统的Cookie。通过对票据产生和传输以及Cookie加密和常见攻击的安全性分析,可以实现跨域单点登录的功能并保证身份认证安全可信。     

陶瓷行业ASP平台安全认证技术的研究与实现

随着应用服务提供商(ASP)商业模式在国内的发展,为满足陶瓷行业ASP平台集成多种异构应用系统的实际需求,该文提出了一种采用统一安全认证技术进行轻量级应用集成的解决方案。方案中采用目录服务数据库统一存储用户身份和权限信息,使用会话令牌保证用户身份的持久有效性,通过策略代理保护应用服务资源的安全,并对用户的访问进行统一授权和控制。为实现用户在平台和应用系统之间的单点登录,提出了结合令牌和代理进行身份信息传递与验证的实现方案,尤其是解决了跨域单点登录(SSO)的难题。     

单点登录在企业门户中的实现

本文首先介绍了企业门户和单点登录的概念,论述单点登录是实现企业门户的关键。在了解了单点登录的现有实现后,给出了一种基于URL重定向及Session信息共享的单点登录实现方案。     

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。     

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.     

Editorial: Special issue on recent advances in hybrid control theory and applications

正The demands of a rapidly advancing technology for faster and more accurate controllers have always had a strong influence on the progress of automatic control theory.In recent years control problems have been arising with increasing frequency in widely different areas,which cannot be addressed using conventional control techniques.The principal reason for this is the fact that a highly competitive economy is forcing systems to operate in regimes where     

Information for Authors

正Aim The Journals of Zhejiang University-SCIENCE(A/B/C)areedited by the international board of distinguished Chinese andforeign scientists,and are aimed to present the latest devel-opments and achievements in scientific research in China andoverseas to the world’s scientific circles,especially to stimulateand promote academic exchange between Chinese and for-eign scientists everywhere.     

Enhancing a leaf radiative transfer model to estimate concentrations and in vivo specific absorption coefficients of total carotenoids and chlorophylls a and b from single-needle reflectance and transmittance

The relative concentrations of different pigments within a leaf have significant physiological and spectral consequences. Photosynthesis, light use efficiency, mass and energy exchange, and stress response are dependent on relationships among an ensemble of pigments. This ensemble also determines the visible characteristics of a leaf, which can be measured remotely and used to quantify leaf biochemistry and structure. But current remote sensing approaches are limited in their ability to resolve individual pigments. This paper focuses on the incorporation of three pigments—chlorophyll a, chlorophyll b, and total carotenoids—into the LIBERTY leaf radiative transfer model to better understand relationships between leaf biochemical, biophysical, and spectral properties.Pinus ponderosa and Pinus jeffreyi needles were collected from three sites in the California Sierra Nevada. Hemispheric single-leaf visible reflectance and transmittance and concentrations of chlorophylls a and b and total carotenoids of fresh needles were measured. These data were input to the enhanced LIBERTY model to estimate optical and biochemical properties of pine needles. The enhanced model successfully estimated reflectance (RMSE = 0.0255, BIAS = 0.00477, RMS%E = 16.7%), had variable success estimating transmittance (RMSE = 0.0442, BIAS = 0.0294, RMS%E = 181%), and generated very good estimates of carotenoid concentrations (RMSE = 2.48 µg/cm², BIAS = 0.143 µg/cm², RMS%E = 20.4%), good estimates of chlorophyll a concentrations (RMSE = 10.7 µg/cm², BIAS = − 0.992 µg/cm², RMS%E = 21.1%), and fair estimates of chlorophyll b concentrations (RMSE = 7.49 µg/cm², BIAS = − 2.12 µg/cm², RMS%E = 43.7%). Overall root mean squared errors of reflectance, transmittance, and pigment concentration estimates were lower for the three-pigment model than for the single-pigment model. The algorithm to estimate three in vivo specific absorption coefficients is robust, although estimated values are distorted by inconsistencies in model biophysics. The capacity to invert the model from single-leaf reflectance and transmittance was added to the model so it could be coupled with vegetation canopy models to estimate canopy biochemistry from remotely sensed data.     

Mr. Twinn’s bombes

This article discusses the history and design of the special versions of the bombe key-finding machines used by Britain’s Government Code & Cypher School (GC&CS) during World War II to attack the Enigma traffic of the Abwehr (the German military intelligence service). These special bombes were based on the design of their more numerous counterparts used against the traffic of the German armed services, but differed from them in important ways that highlight the adaptability of the British bombe design, and the power and flexibility of the diagonal board. Also discussed are the changes in the Abwehr indicating system that drove the development of these machines, the ingenious ways in which they were used, and some related developments involving the bombes used by the U.S. Navy’s cryptanalytic unit (OP-20-G).