多级安全数据库管理系统查询处理器的设计

多级安全数据库与传统的数据库最大的不同就在于它引入了安全级的概念，访问数据库的主体和数据库中的客体都被赋予了安全级，主体对客体的访问遵循强制存取控制规则．多级安全查询处理器是多级安全数据库的核心部分，它提供对安全级查询的支持．多级安全查询处理器必须保证用户的查询不违反数据库系统安全性的要求．分析了多级安全查询处理的执行过程，定义了多级安全查询语言的语法，利用编译器生成工具Yacc设计了一个多级安全查询处理器，并对其进行了分析．     

部分相容关系的集合运算及其在数据库查询语言中的应用

将同类关系上的运算交、并、差以及对乐差扩充到非同类关系上，同时引入了一个新的关系运算－拼接，并对以上各运算的性质进行了讨论，最后，介绍了这些运算在关系数据库子模式查询语言ＶＱＬ中的应用。     

一个基于Authorware的SQL数据库开发

基于Authorware附带的数据库编程接口Odbc.u32的打开数据库、SQL语句的执行、关闭数据库等3个功能，探讨SQL数据库应用程序的开发，并给出了一个实例。     

分布式数据库中关系运算结果大小的估计

本文在分析了原有的几种估计关系运算结果大小的方法的基础上,提出了一新的估计模型——UDB,并对其建造方法、使用方法、适用情况及估计精度做了较详细的讨论。     

A Designated Query Protocol for Serverless Mobile RFID Systems with Reader and Tag Privacy

Recently, a new type of Radio Frequency IDentification (RFID) system with mobile readers is introduced. In such a system, it is more desirable for mobile readers to identify tags without a back-end server, and thus it is frequently referred as a serverless mobile RFID system. In this paper, we formalize a serverless mobile RFID system model and propose a new encryption-based system that preserves the privacy of both tags and readers in the model. In addition, we define a new adversary model for the system model and show the security of the proposed system. Throughout comparisons between ours and the other alternatives, we show that our proposed system provides a stronger reader privacy and robustness against a reader forgery attack than the competitors.     

Efficient evaluation of monitoring top-t most influential places

The continuous top-t most influential place (CTtMIP) query is defined formally and solved efficiently in this paper. A CTtMIP query continuously monitors the t places with the maximum influence from the set of places, where the influence of a place is defined as the number of its bichromatic reverse k nearest neighbors (BRkNNs). Two new metrics and their corresponding rules are introduced to shrink the search region and reduce the candidates of BRkNNs checked. Extensive experiments confirm that our proposed approach outperforms the state-of-the-art competitor significantly.     

Some classes of disconnected antimagic graphs and their joins

A labeling of a graph G is a bijection from E(G) to the set {1,2,…,|E (G)| }.A labeling is antimagic if for any distinct vertices x and y,the sum of the labels on edges incident to x is different from the sum of the labels on edges incident to y.We say that a graph is antimagic if it has an antimagic labeling.Hartsfield and Ringel conjectured in 1990 that every graph other than 2 K is antimagic.In this paper,we show that the antimagic conjecture is false for the case of disconnected graphs.Furthermore,we find some classes of disconnected graphs that are antimagic and some classes of graphs whose complement are disconnected are antimagic.     

Web图像搜索系统中用户交互及反馈系统模型

提出一种用于图像搜索系统的用户交互和反馈模型,采用多模式查询方式满足不同用户的查询需求,加之完全基于用户语义理解的反馈策略,有效提高了系统准确性.作为整个图像搜索系统中直接面向用户的模块,整个交互及反馈系统简单易用、灵活方便,更适用于一般用户的"傻瓜式"查询需求.基于内容的图像搜索系统VAST(Visual ＆ Semantic Image Search)及反馈性能测试充分证明了该交互及反馈系统在Web环境下图像搜索领域的优势.     

网格中间件快速查询数据的VC++实现

介绍了VC^ 中的网格控件DBGrid和RDC,并利用它们实现普通数据查询和高级数据查询的功能．详细分析了工程实现的流程并给出一个具体的应用实例、结果表明：该方法无需额外复杂的编程,具有方便简洁和实用的特点．     

一种安全相关输入输出数据总线的实现

提出了一种在SPI总线上利用循环冗余校验码(CRC)、安全码和停等式自动反馈重传(ARQ)实现安全相关闭环传输的方法,给出了硬件电路设计方法和仿真结果.