To model the operation of food traceability, features of food supply chain are studied. The aim of the paper is to build an abstract model of food traceability, and to gain better understanding of food traceability an...To model the operation of food traceability, features of food supply chain are studied. The aim of the paper is to build an abstract model of food traceability, and to gain better understanding of food traceability and food safety. Based on the analysis of consumers＇ behavior of searching for traceability information, a finite state automaton for food traceability is presented by using automata theory. The states of the food supply chain are represented by a state transition diagram. The automaton in this paper simulates the entire food supply chain and provides a theoretical basis for the behavior description and structural design of a food traceability system.展开更多
1-way multihead quantum finite state automata (1QFA(k)) can be thought of modified version of 1-way quantum finite state automata (1QFA) and k-letter quantum finite state automata (k-letter QFA) respectively. It has b...1-way multihead quantum finite state automata (1QFA(k)) can be thought of modified version of 1-way quantum finite state automata (1QFA) and k-letter quantum finite state automata (k-letter QFA) respectively. It has been shown by Moore and Crutchfield as well as Konadacs and Watrous that 1QFA can’t accept all regular language. In this paper, we show different language recognizing capabilities of our model 1-way multihead QFAs. New results presented in this paper are the following ones: 1) We show that newly introduced 1-way 2-head quantum finite state automaton (1QFA(2)) structure can accept all unary regular languages. 2) A language which can’t be accepted by 1-way deterministic 2-head finite state automaton (1DFA((2)) can be accepted by 1QFA(2) with bounded error. 3) 1QFA(2) is more powerful than 1-way reversible 2-head finite state automaton (1RMFA(2)) with respect to recognition of language.展开更多
针对访问控制策略评估效率问题,提出基于有限状态自动机(finite state automaton,FSA)和重排序的访问控制策略评估方案。以四元组的形式表示策略,构建FSA策略模型检测策略异常,消除策略中的冲突规则以及冗余规则,实现策略评估的前期优化...针对访问控制策略评估效率问题,提出基于有限状态自动机(finite state automaton,FSA)和重排序的访问控制策略评估方案。以四元组的形式表示策略,构建FSA策略模型检测策略异常,消除策略中的冲突规则以及冗余规则,实现策略评估的前期优化;提出基于重排序的策略评估算法,重排序策略中的规则以及每个规则中的属性-值对(attribute-value pairs,AVP),减少评估访问请求过程中遍历的规则数和属性比较次数。实验结果表明,与传统策略评估引擎相比,该方案检测策略异常效率以及评估效率均有很大提升。展开更多
以传统有限自动机(finite state automata,简称FSA)为基础,从系统调用参数中解析出系统对象,提出了一种基于系统对象的软件行为模型(model of software behavior based on system objects,简称SBO).该模型的行为状态由软件所关联的所有...以传统有限自动机(finite state automata,简称FSA)为基础,从系统调用参数中解析出系统对象,提出了一种基于系统对象的软件行为模型(model of software behavior based on system objects,简称SBO).该模型的行为状态由软件所关联的所有系统对象表示,从而赋予状态的语义信息,解决了不同行为迹中PC(program counter)值的语义不相关问题;同时,该模型可以对抗系统调用参数的直接和间接修改,从而可以检测基于数据语义的攻击.最后,实现了基于SBO的软件异常检测原型工具(intrusion detection prototype system based on SBO,简称SBOIDS),其实验和分析结果表明,该模型可以有效地检测基于控制流的攻击、模仿攻击以及针对数据语义的攻击,并给出了该工具的性能开销.展开更多
基金supported by the Science and Technology Public Projects of Sichuan under Grant No. 07GF001-0032010 Ministry of Science and Technology Innovation Fund for SMEs under Grant No. 10C26225123015
文摘To model the operation of food traceability, features of food supply chain are studied. The aim of the paper is to build an abstract model of food traceability, and to gain better understanding of food traceability and food safety. Based on the analysis of consumers＇ behavior of searching for traceability information, a finite state automaton for food traceability is presented by using automata theory. The states of the food supply chain are represented by a state transition diagram. The automaton in this paper simulates the entire food supply chain and provides a theoretical basis for the behavior description and structural design of a food traceability system.
文摘1-way multihead quantum finite state automata (1QFA(k)) can be thought of modified version of 1-way quantum finite state automata (1QFA) and k-letter quantum finite state automata (k-letter QFA) respectively. It has been shown by Moore and Crutchfield as well as Konadacs and Watrous that 1QFA can’t accept all regular language. In this paper, we show different language recognizing capabilities of our model 1-way multihead QFAs. New results presented in this paper are the following ones: 1) We show that newly introduced 1-way 2-head quantum finite state automaton (1QFA(2)) structure can accept all unary regular languages. 2) A language which can’t be accepted by 1-way deterministic 2-head finite state automaton (1DFA((2)) can be accepted by 1QFA(2) with bounded error. 3) 1QFA(2) is more powerful than 1-way reversible 2-head finite state automaton (1RMFA(2)) with respect to recognition of language.
文摘针对访问控制策略评估效率问题,提出基于有限状态自动机(finite state automaton,FSA)和重排序的访问控制策略评估方案。以四元组的形式表示策略,构建FSA策略模型检测策略异常,消除策略中的冲突规则以及冗余规则,实现策略评估的前期优化;提出基于重排序的策略评估算法,重排序策略中的规则以及每个规则中的属性-值对(attribute-value pairs,AVP),减少评估访问请求过程中遍历的规则数和属性比较次数。实验结果表明,与传统策略评估引擎相比,该方案检测策略异常效率以及评估效率均有很大提升。
文摘以传统有限自动机(finite state automata,简称FSA)为基础,从系统调用参数中解析出系统对象,提出了一种基于系统对象的软件行为模型(model of software behavior based on system objects,简称SBO).该模型的行为状态由软件所关联的所有系统对象表示,从而赋予状态的语义信息,解决了不同行为迹中PC(program counter)值的语义不相关问题;同时,该模型可以对抗系统调用参数的直接和间接修改,从而可以检测基于数据语义的攻击.最后,实现了基于SBO的软件异常检测原型工具(intrusion detection prototype system based on SBO,简称SBOIDS),其实验和分析结果表明,该模型可以有效地检测基于控制流的攻击、模仿攻击以及针对数据语义的攻击,并给出了该工具的性能开销.
