Object-oriented DBMS requirements

The requirements on an object-oriented DBMS for management of information in a large, complex enterprise are presented. These requirements aid in the achievement of an environment characterized by data sharing, open architectures, application and data portability, and assurance of data integrity. They were defined from the point of view of a user of the DBMS; therefore they describe the expected functionality of the DBMS and do not specify the method of implementation to achieve this functionality. They encompass requirements on the data model, query and data manipulation languages, the system architecure, interfaces to the system, change management, and transaction management.     

Data Squashing by Empirical Likelihood

Data squashing was introduced by W. DuMouchel, C. Volinsky, T. Johnson, C. Cortes, and D. Pregibon, in Proceedings of the 5th International Conference on KDD (1999). The idea is to scale data sets down to smaller representative samples instead of scaling up algorithms to very large data sets. They report success in learning model coefficients on squashed data. This paper presents a form of data squashing based on empirical likelihood. This method reweights a random sample of data to match certain expected values to the population. The computation required is a relatively easy convex optimization. There is also a theoretical basis to predict when it will and won't produce large gains. In a credit scoring example, empirical likelihood weighting also accelerates the rate at which coefficients are learned. We also investigate the extent to which these benefits translate into improved accuracy, and consider reweighting in conjunction with boosted decision trees.     

辽宁省节水工作存在问题及对策

辽宁省是水资源严重短缺的省份之一，水资源不足已成为制约全省经济社会可持续发展的瓶颈。通过对全省大型取用水户的调查分析，找出了辽宁省节水工作中存在的问题，提出了节约用水工作的对策和建议。     

On assertion-based encapsulation for object invariants and simulations

In object-oriented programming, reentrant method invocations and shared references make it difficult to achieve adequate encapsulation for sound modular reasoning. This tutorial paper surveys recent progress using auxiliary state (ghost fields) to describe and achieve encapsulation. It also compares this technique with encapsulation in the forms provided by separation logic. Encapsulation is assessed in terms of modular reasoning about invariants and simulations.     

晋煤集团赵庄煤矿建筑外部空间规划浅谈

通过对晋煤集团赵庄煤矿建筑外部空间规划的实例分析,综合考虑工业、行政、生活区的不同功能,构建园林、人文、旅游式矿山,从文化提炼、总体把握、景观构成等方面解决了煤矿建设中的可持续发展问题,以达到良好的规划效果。     

Information Visualization Within a Digital Video Library

The Informedia Digital Video Library contains over a thousand hours of video, consuming over a terabyte of disk space. This paper summarizes the multimedia abstractions used to represent this video in prior systems and introduces the visualization techniques employed to browse and navigate multiple video documents at once.     

OAuth2.0协议形式化验证: 使用AVISPA

OAuth协议是一套用于在不同的服务中进行身份认证并且实现资源互访一套协议.由于关系到用户隐私,所以OAuth协议的安全性非常重要.这篇文章的主要贡献是研究OAuth2.0协议文本,对协议进行抽象,并且使用验证工具AVISPA对抽象后的协议进行建模与验证,找到协议中会导致隐私泄露的一种攻击模式.我们在建模过程中提出需将要验证的消息作为双方的对称密码这样一种创新思路.这种对协议的抽象和验证的方法可以推广到其他安全协议上,例如在线支付协议等等.     

Abstraction of levels of abstraction

The notion of level of abstraction (LoA) is one of the foundations of the Floridi's Philosophy of Information. It also serves for many practical purposes as in information ethics. But the notion of abstraction is not new; it has been given many different meanings in various fields, especially in scientific disciplines and, in particular, in computer science. Our purpose here is to examine the use of abstraction in Floridi's works in conjunction with some of the meanings of abstraction in computer science. The article is divided into five sections. After a general introduction to the Floridi's method of abstraction (MoA) in Section 1, Section 2 revisits Floridi's definition of abstraction and Section 3 gives the different senses of abstraction in computer science. The Section 4 compares them with the Floridi's LoAs and proposes to generalise the Floridi's approach to abstraction using an abstraction of the LoAs, while Section 5 concludes on what we think to be some new arguments in favour of MoA and LoA.     

基于抽象和组合方法的网络协议验证

由于模型检测存在状态爆炸问题,多主体的网络协议组合模型检测往往难以进行。为了缓解该问题,分析了通信主体数量增加对状态数量的影响,提出了组合式的抽象验证方法。首先根据所需验证的LTL性质,建立各个通信主体的Kripke结构,再对该Kripke结构进行抽象;然后组合抽象模型;最后运用Spin对组合抽象模型进行检验。为验证该方法的有效性,对NSPK协议进行了检测,结果表明,该方法所需的状态空间向量长度、搜索深度、存贮和遍历的状态数都有明显减少,有利于缓解状态爆炸问题。