The equivalence exists between regular grammar and finite automata in accepting languages. Some complicated conversion algorithms have also been in existence. The simplified forms of the algorithms and their proofs ar...The equivalence exists between regular grammar and finite automata in accepting languages. Some complicated conversion algorithms have also been in existence. The simplified forms of the algorithms and their proofs are given. And the construction algorithm 5 of the equivalent conversion from finite automata to left linear grammar is presented as well as its correctness proof. Additionally, a relevant example is expounded.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
Nowadays, using Deterministic Finite Automata (DFA) or Non-deterministic Finite Automata (NFA) to parse regular expressions is the most popular way for Deep Packet Inspection (DPI), and the research about DPI focuses ...Nowadays, using Deterministic Finite Automata (DFA) or Non-deterministic Finite Automata (NFA) to parse regular expressions is the most popular way for Deep Packet Inspection (DPI), and the research about DPI focuses on the improvement of DFA to reduce memory. However, most of the existing literature ignores a special kind of "overlap-matching expression", which causes states explosion and takes quite a large part in the DPI rules. To solve this problem, in this paper a new mechanism is proposed based on bitmap. We start with a simple regular expression to describe "overlap-matching expressions" and state the problem. Then, after calculating the terrible number of exploded states for this kind of expressions, the procedure of Bitmap-based Soft Parallel Mechanism (BSPM) is described. Based on BSPM, we discuss all the different types of "overlap-matching ex- pressions" and give optimization suggestions of them separately. Finally, experiment results prove that BSPM can give an excellent performance on solving the problem stated above, and the optimization suggestions are also effective for the memory reduction on all types of "overlap-matching expressions".展开更多
文摘The equivalence exists between regular grammar and finite automata in accepting languages. Some complicated conversion algorithms have also been in existence. The simplified forms of the algorithms and their proofs are given. And the construction algorithm 5 of the equivalent conversion from finite automata to left linear grammar is presented as well as its correctness proof. Additionally, a relevant example is expounded.
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.
基金河南省杰出人才创新基金项目(the Innovation Fundation for Talents of Henan Province under Grant No.074200510013)河南省教育厅自然科学基金项目(the Natural Science Foundation for Education Department of Henan Province under Grant No.2007520048)。
基金Supported by the National High Technology Development 863 Program of China (No. 2008AA01Z117)
文摘Nowadays, using Deterministic Finite Automata (DFA) or Non-deterministic Finite Automata (NFA) to parse regular expressions is the most popular way for Deep Packet Inspection (DPI), and the research about DPI focuses on the improvement of DFA to reduce memory. However, most of the existing literature ignores a special kind of "overlap-matching expression", which causes states explosion and takes quite a large part in the DPI rules. To solve this problem, in this paper a new mechanism is proposed based on bitmap. We start with a simple regular expression to describe "overlap-matching expressions" and state the problem. Then, after calculating the terrible number of exploded states for this kind of expressions, the procedure of Bitmap-based Soft Parallel Mechanism (BSPM) is described. Based on BSPM, we discuss all the different types of "overlap-matching ex- pressions" and give optimization suggestions of them separately. Finally, experiment results prove that BSPM can give an excellent performance on solving the problem stated above, and the optimization suggestions are also effective for the memory reduction on all types of "overlap-matching expressions".
