• Title, Summary, Keyword: String Pattern Matching

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Development of the Pattern Matching Engine using Regular Expression (정규 표현식을 이용한 패턴 매칭 엔진 개발)

  • Ko, Kwang-Man;Park, Hong-Jin
    • The Journal of the Korea Contents Association
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    • v.8 no.2
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    • pp.33-40
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    • 2008
  • In various manners, string pattern matching algorithm has been proven for prominence in speed of searching particular queries and keywords. Whereas, the existing algorithms are limited in terms of various pattern. In this paper, regular expression has been utilized to improve efficiency of pattern matching through efficient execution towards various pattern of queries including particular keywords. Such as this research would enable to search various harmful string pattern more efficiently, rather than matching simple keywords, which also implies excellent speed of string pattern matching compared to that of those existing algorism. In this research, the proposed string search engine generated from the LEX are more efficient than BM & AC algorithm for a string patterns search speed in cases of 1000 with more than patterns, but we have got similar results for the keywords pattern matching.

Design of String Pattern Matching (SPM) Processor (문자열 패턴 매칭 (SPM:String Pattern Matching)프로세서의 설계)

  • Kook, Il-Ho;Cho, Won-Kyung
    • Proceedings of the KIEE Conference
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    • pp.659-661
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    • 1988
  • SPM is MDC Processor for string pattern expressed in directional chain code. In this paper we consider the string pattern matching algorithm (Leve-nstein Algorithm) whitch is portion of Dynamic Programing, and propose architecture of SPM and simulate it on the R-T level to evaluate its architecture. We used the C language as the hardware description language, and developed it on the IBM PC/AT Zenix system V OS environment.

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Retargetable Intermediate Code Optimization System Using Tree Pattern Matching Techniques (트리패턴매칭기법의 재목적 가능한 중간코드 최적화 시스템)

  • Kim, Jeong-Suk;O, Se-Man
    • The Transactions of the Korea Information Processing Society
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    • v.6 no.8
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    • pp.2253-2261
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    • 1999
  • ACK generates optimized code using the string pattern matching technique in pattern table generator and peephole optimizer. But string pattern matching method is not effective due to the many comparative actions in pattern selection. We designed and implemented the EM intermediate code optimizer using tree pattern matching algorithm composed of EM tree generator, optimization pattern table generator and tree pattern matcher. Tree pattern matching algorithm practices the pattern matching that centering around root node with refer to the pattern table, with traversing the EM tree by top-down method. As a result, compare to ACK string pattern matching methods, we found that the optimized code effected to pattern selection time, and contributed to improved the pattern selection time by about 10.8%.

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A Memory-Efficient Two-Stage String Matching Engine Using both Content-Addressable Memory and Bit-split String Matchers for Deep Packet Inspection (CAM과 비트 분리 문자열 매처를 이용한 DPI를 위한 2단의 문자열 매칭 엔진의 개발)

  • Kim, HyunJin;Choi, Kang-Il
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.39B no.7
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    • pp.433-439
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    • 2014
  • This paper proposes an architecture of two-stage string matching engine with content-addressable memory(CAM) and parallel bit-split string matchers for deep packet inspection(DPI). Each long signature is divided into subpatterns with the same length, where subpatterns are mapped onto the CAM in the first stage. The long pattern is matched in the second stage using the sequence of the matching indexes from the CAM. By adopting CAM and bit-split string matchers, the memory requirements can be greatly reduced in the heterogeneous string matching environments.

A Hardware-Based String Matching Using State Transition Compression for Deep Packet Inspection

  • Kim, HyunJin;Lee, Seung-Woo
    • ETRI Journal
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    • v.35 no.1
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    • pp.154-157
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    • 2013
  • This letter proposes a memory-based parallel string matching engine using the compressed state transitions. In the finite-state machines of each string matcher, the pointers for representing the existence of state transitions are compressed. In addition, the bit fields for storing state transitions can be shared. Therefore, the total memory requirement can be minimized by reducing the memory size for storing state transitions.

Pattern Recognition Method Using Fuzzy Clustering and String Matching (퍼지 클러스터링과 스트링 매칭을 통합한 형상 인식법)

  • 남원우;이상조
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.17 no.11
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    • pp.2711-2722
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    • 1993
  • Most of the current 2-D object recognition systems are model-based. In such systems, the representation of each of a known set of objects are precompiled and stored in a database of models. Later, they are used to recognize the image of an object in each instance. In this thesis, the approach method for the 2-D object recognition is treating an object boundary as a string of structral units and utilizing string matching to analyze the scenes. To reduce string matching time, models are rebuilt by means of fuzzy c-means clustering algorithm. In this experiments, the image of objects were taken at initial position of a robot from the CCD camera, and the models are consturcted by the proposed algorithm. After that the image of an unknown object is taken by the camera at a random position, and then the unknown object is identified by a comparison between the unknown object and models. Finally, the amount of translation and rotation of object from the initial position is computed.

Fast Matching Method for DNA Sequences (DNA 서열을 위한 빠른 매칭 기법)

  • Kim, Jin-Wook;Kim, Eun-Sang;Ahn, Yoong-Ki;Park, Kun-Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.36 no.4
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    • pp.231-238
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    • 2009
  • DNA sequences are the fundamental information for each species and a comparison between DNA sequences of different species is an important task. Since DNA sequences are very long and there exist many species, not only fast matching but also efficient storage is an important factor for DNA sequences. Thus, a fast string matching method suitable for encoded DNA sequences is needed. In this paper, we present a fast string matching method for encoded DNA sequences which does not decode DNA sequences while matching. We use four-characters-to-one-byte encoding and combine a suffix approach and a multi-pattern matching approach. Experimental results show that our method is about 5 times faster than AGREP and the fastest among known algorithms.

Design and Implementation of High-Speed Pattern Matcher in Network Intrusion Detection System (네트워크 침입 탐지 시스템에서 고속 패턴 매칭기의 설계 및 구현)

  • Yoon, Yeo-Chan;Hwang, Sun-Young
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.33 no.11B
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    • pp.1020-1029
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    • 2008
  • This paper proposes an high speed pattern matching algorithm and its implementation. The pattern matcher is used to check patterns from realtime input packet. The proposed algorithm can find exact string, range of string values, and combination of string values from input packet at high speed. Given string and rule set are modelled as a state transition graph which can find overlapped strings simultaneously, and the state transition graph is partitioned according to input implicants to reduce implementation complexity. The pattern matcher scheme uses the transformed state transition graph and input packet as an input. The pattern matcher was modelled and implemented in VHDL language. Experimental results show the proprieties of the proposed approach.

An Index Data Structure for String Search in External Memory (외부 메모리에서 문자열을 효율적으로 탐색하기 위한 인덱스 자료 구조)

  • Na, Joong-Chae;Park, Kun-Soo
    • Journal of KIISE:Computer Systems and Theory
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    • v.32 no.11_12
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    • pp.598-607
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    • 2005
  • We propose a new external-memory index data structure, the Suffix B-tree. The Suffix B-tree is a B-tree in which the key is a string like the String B-tree. While the node in the String B-tree is implemented with a Patricia trio, the node in the Suffix B-tree is implemented with an array. So the Suffix B-tree is simpler and easier to be Implemented than the String B-tree. Nevertheless, the branching algorithm of the Suffix B-tree is as efficient as that of the String B-tree. Consequently, the Suffix B-tree takes the same worst-case disk accesses as the String B-tree to solve the string matching problem, which is fundamental and important in the area of string algorithms.

A Study on 1-D Bit-Serial Array Processor Design for Code-String Matching Using a MWLD Algorithm (MWLD 알고리즘을 이용한 문자열정합 1차원 Bit-Serial 어레이 프로세서의 설계)

  • 박종진;김은원;조원경
    • Journal of the Korean Institute of Telematics and Electronics B
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    • v.29B no.2
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    • pp.1-8
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    • 1992
  • This paper is proposed a Modified WLD (Weighted Levenshtein Distance) algorithm for processor desihn of code-string matching. A proposed MWLD (Modified Weighted Levenshtein Distance) algorithm is consist of 1-dimension bit-serial array processor to pattern matching using a Hamming Distance. The proposed processor is applied to recognition of character with real time input. The recognition rate of Hangul strokes is resulted to 98.65$\%$

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