Security constraints are consistent by modifying security constraint definition , and an effective classification assignment algorithm is given in this paper . we analyze the problem of inference channel and give solution to solve the problem during database analysis and design period . by analyzing the problems resulting from extending single - level transactions to multilevel transactions , we also give a multilevel secure transaction schedule algorithm based multiversion snapshot graph 本文提出采用主从结构表的方法对blp模型加以改造,使得改造后的blp模型具有较高的可用性和安全性;通过修改安全约束的定义,使得安全约束之间始终是协调的,并给出一种高效的密级分配算法;讨论了推理通道问题,给出了在数据库分析、设计等阶段可以采用的对策;分析了事务从传统的单级扩展到多级面临的众多难题,给出了一种基于多版本串行化图的事务调度算法;根据上述理论,开发了一个多级安全数据库管理系统的原型系统。
Next , a novel priority - based wavelength assignment algorithm in all - optical networks with partial wavelength conversion is proposed , based on link independent assumption and the method of calculating the network the blocks probability . it improves the routing and wavelength assignment presented by others . this algorithm fits the demand of different business for asking the grade of corresponding different services in the modern all - optical network than the original algorithm 其次研究了部分波长可变wdm网中支持优先级的波长分配问题,以及在此网络中网络阻塞概率的计算;基于链路波长占用独立性假设,改进了在部分波长转换wdm网中已有的rwa算法,提出了一种支持优先级的动态波长分配算法,该算法保证了较高优先级的光路建立请求具有较低的阻塞率,比原有算法更加适合现代光网络中不同业务请求对应不同服务等级的要求。