多级安全空间数据库的语义

本文提出了为每一元素（数据项）赋予安全级时的多级关系－层次数据模型，该模型处理多级空间数据，在该模型下，引入了上下层关系完整性，在吸收基于信赖的语义和基于事实的语义思想的基础上，修改了SELECT语句的格式和语义，扩充了MLR中基于数据的语义，为防止数据模型引入的隐通道，我们修改了MLR中其它SQL语句的语义和处理，最后证明了多级关系－层次数据模型是安全的。     

移动自组网中多级安全事务的并发控制

为满足移动自组网(MANETS)多级事务处理的安全性和并发性要求,将多版本两段锁协议运用到MANETS多级事务中。该协议有效地解决了由于竞争产生的错误的事务调度以及安全问题。模拟仿真结果表明,多版本两段锁协议在延迟截至时间率和重启动率方面比单一的多版本协议或者单一的两段锁协议都要低。     

基于多版本快照的多级安全事务调度算法

现有的各种用于多级事务调度的算法都主要是采用锁机制来解决的,在多级安全系统环境中,正是这个锁机制使得系统在高低安全级事务发生读写冲突时无所适从,从而使得这些算法都只能各自处理某些类多级事务.针对这些缺陷,文中提出了一种有效的、无需对数据上锁的多级安全事务调度算法--多版本快照算法.算法通过消除多版本串行化图(Multiversion Seriarization Graph,MSG)中出现环的方法来达到并行事务的可串行化.文中还证明了算法的正确性,并对算法的安全性进行了分析.     

一种多级安全数据模型中的多实例语义

为了对低安全级的主体(用户)隐藏高安全级的敏感信息,在多级安全数据模型中引入了多实例的概念.关于多实例的语义以及维护一直是多级安全数据模型的研究热点.提出了一种新的多实例语义MLS-POS,并给出了该语义下维护多实例的方法. MLS-POS最大的特点是能够限制低级别用户修改高级别数据的程度,弱化高级别数据与低级别数据的依赖关系,在该语义下维护多实例元组时更具安全性与合理性.     

多级安全数据库系统中多级事务原子性的研究

文章在证明了不可能同时保证多级事务的原子性和安全性的基础上,介绍了多级事务三种不同程度的原子性,给出了两种基本算法,并通过引入多版本机制消除事务节间的语义依赖。     

多级安全数据库系统推理问题研究

在多级安全数据库系统中,推理问题是低安全级的用户利用他能够访问到的数据以及自身的知识,推断出高安全级的机密信息,从而构成对数据库的攻击。该文综述了控制数据库推理问题的方法,并比较了它们的优缺点。     

多级数据库安全模型

多级安全是指一种保护敏感级信息资源不被非法使用的控制策略，它将系统内的主体（如用户、进程、事务）与客体（如文件、设备、表、元组等）按需要分成不同的安全级，通过安全级来限制主体对客体的访问。数据库管理系统中的多级安全是指每个主体（直接或间接）仅能访问其有许可权的客体。作者研究出一个实现强制访问控制和自主访问控制的多级安全数据库模型，模型满足TCSEC的B1级安全要求。     

LogicSQL多级安全数据库的研究与实现

结合数据库的用户身份认证与自主访问控制研究．设计了LogicSQL多级安全模型。该模型把安全级分为分层密级和非分层的范围组成的二元组形式，主要从安全标签、强制访问控制和审计方面进行讨论。该模型在企业搜索与公安系统中得到应用。     

多级安全工作流的任务依赖的语义分类问题研究

工作流管理系统支持在一个组织机构内部的过程的建模和协调执行。通常,为了在一个工作流中协调各种任务（Tasks）或活动的执行,在各种任务之间引入了任务依赖。而在一个多级安全工作流中,任务可能属于不同的安全级别。从高安全级的任务到低安全级的任务的依赖有可能损害安全性,为了探讨以正确而又安全的方法进行执行的方法,分析了任务依赖的来源,其依据是任务依赖的语义分类。然后给出了自动进行分类的算法。     

MLS DBMS中的多实例问题分析及解决方法

1.引言 MLS DBMS(多级安全数据库管理系统)采用MAC(强制访问控制)阻止高安全级的数据未经授权被泄露给低安全级的用户,推理(Inference)是对MAC策略的一种威胁:低安全级的用户能从低安全级的数据结合相关知识等推理出高安全级别的信息。提高某些处于推理链中的关键数据元素的安全级并不能完全     

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     

煤矿井下安全监控分站的设计及其仿真实现

为了设计一种具有低成本、低功耗、易操作、功能强且可靠性高的煤矿井下安全分站,针对煤矿安全生产实际,文章提出了采用MCS-51系列单片机为核心、具有CAN总线通信接口的煤矿井下安全监控分站的设计方案;首先给出煤矿井下安全监控分站的整体构架设计,然后着重阐述模拟量输入信号处理系统的设计过程,最后说明单片机最小系统及其键盘、显示、报警、通信等各个组成部分的设计;为验证设计方案的可行性与有效性,使用Proteus软件对设计内容进行仿真验证,设计的煤矿井下安全监控分站具有瓦斯、温度等模拟量参数超标报警功能和电机开停、风门开闭等开关量指示功能;仿真结果表明:设计的煤矿井下安全监控分站具有一定的实际应用价值.     

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。