• Title/Summary/Keyword: 논리곱

Search Result 58, Processing Time 0.026 seconds

(The Minimization of Boolean functions to the Exclusive-OR sum of Products logic) (부울함수의 논리곱의 배타적 합 논리로의 간략화)

  • 이진흥;이상곤;문상재;서용수;김태근;정원영
    • Proceedings of the Korea Institutes of Information Security and Cryptology Conference
    • /
    • 1997.11a
    • /
    • pp.315-321
    • /
    • 1997
  • 본 논문에서는 임의의 부울함수(Boolean function)에 대한 진리표나 출력 시퀀스로부터 논리곱의 배타적 합(exclusive-or sum of products; ESOP)형의 부울함수를 구성하는 알고리듬을 제안한다. 기존에 알려진 카르노맵이나 Quine HcClusky법에 의하여 구해지는 부울함수는 논리곱의 합(sum of product; SOP) 형으로 주어지며 이들 수식은 부정(NOT)논리를 포함하는 경우가 있다. 제안된 알고리듬에 의하여 구해지는 부울함수는 구조적인 등가성을 판별하는데 편리하므로 해쉬함수용 부울함수의 개발에 이용될 수 있다.

  • PDF

Conjunctive Boolean Query Optimization based on Join Sequence Separability in Information Retrieval Systems (정보검색시스템에서 조인 시퀀스 분리성 기반 논리곱 불리언 질의 최적화)

  • 박병권;한욱신;황규영
    • Journal of KIISE:Databases
    • /
    • v.31 no.4
    • /
    • pp.395-408
    • /
    • 2004
  • A conjunctive Boolean text query refers to a query that searches for tort documents containing all of the specified keywords, and is the most frequently used query form in information retrieval systems. Typically, the query specifies a long list of keywords for better precision, and in this case, the order of keyword processing has a significant impact on the query speed. Currently known approaches to this ordering are based on heuristics and, therefore, cannot guarantee an optimal ordering. We can use a systematic approach by leveraging a database query processing algorithm like the dynamic programming, but it is not suitable for a text query with a typically long list of keywords because of the algorithm's exponential run-time (Ο(n2$^{n-1}$)) for n keywords. Considering these problems, we propose a new approach based on a property called the join sequence separability. This property states that the optimal join sequence is separable into two subsequences of different join methods under a certain condition on the joined relations, and this property enables us to find a globally optimal join sequence in Ο(n2$^{n-1}$). In this paper we describe the property formally, present an optimization algorithm based on the property, prove that the algorithm finds an optimal join sequence, and validate our approach through simulation using an analytic cost model. Comparison with the heuristic text query optimization approaches shows a maximum of 100 times faster query processing, and comparison with the dynamic programming approach shows exponentially faster query optimization (e.g., 600 times for a 10-keyword query).

Fuzzy Traffic Control Expert System (퍼지 교통 제어 전문가 시스템)

  • 진정애;김용기
    • Journal of Intelligence and Information Systems
    • /
    • v.1 no.2
    • /
    • pp.17-32
    • /
    • 1995
  • 본 논문에서는 추론엔진 (inference engine)내에 퍼지정보 검색부(Fuzzy Information Retrieval part)를 갖는 교통신도 제어 전문가 시스템을 제안한다. 제안하는시스템은 다양하고 복잡한 도로 상화을 고려하여 그에 따른 적절한 주기를 각 도로별로 할당함으로써 원활한 교통 흐름을 제어한다. 추론엔진내의 퍼지정보 검색부는 퍼지 삼각 논리곱을 이용하여 도로의 상황을 분석한 후 각 도로에 맞는 가장 적절한 신호주기를 생성한다.

  • PDF

BAR: Bitmap-based Association Rule-Implementation and its Optimizations (BAR: 비트맵 기반의 연관규칙 구현 및 최적화)

  • Kim Jae-Myung;Oh Ki-Sun;Kim Dong-Hyun;Lee Sang-Won
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2005.11b
    • /
    • pp.58-60
    • /
    • 2005
  • 대표적인 데이터마이닝 문제중의 하나인 연관규칙 탐사에는 지금까지 Apriori 기반의 많은 알고리즘들이 개발되어 왔다. 본 논문에서는 비트맵을 이용한 Apriori 알고리즘 구현방안을 제시한다. 우선, 핵심연산인 비트맵 논리곱(Bitmap AND)과 비트 카운팅(bit-counting)을 컴퓨터 CPU의 고급 기술을 이용해서 효과적으로 구현할 수 있음을 보인다. 또한, 트랜잭션 데이터를 비트맵으로 표현함으로써, 기존 Apriori와는 달리, 비트맵 논리곱 연산을 획기적으로 줄일 수 있는 방법을 제시한다. BAR의 이러한 구현기법을 통해, Apriori 기반의 최신 구현 방법에 비해, 성능이 최대 30배 정도 향상됨을 보인다.

  • PDF

Source to teminal reliability evaluation by network decomposition (분할에 의한 네트워크의 국간신뢰도 계산)

  • 서희종;최종수
    • The Journal of Korean Institute of Communications and Information Sciences
    • /
    • v.21 no.2
    • /
    • pp.375-382
    • /
    • 1996
  • In this paper, aneffective method for computing source to terminal reliability of network by decomposition is described. A graph is modeled after a network, and decomposed into two subgraphs. A logic product term of one subgraph is computed, and a graph of the other subgraphs is made according to the event representing the logic product term, and it's logic product term is compted. By multiplying the logic product term of one subgraph by that of the other subgraphs, a method for computing the source to terminal reliability is proposed. the time complexity for computing all the logic product terms of one subgraph is the product of copies of the number of edges in the subgraph of 2, and that of the other subgraph is the number of edges multiplied by the number of logic product terms. This method requires less computation time than that not by decomposition.

  • PDF

Study on Construction of Multiple-Valued Logic Circuits Based on Reed-Muller Expansions (Reed-Muller 전개식에 의한 다치 논리회로의 구성에 관한 연구)

  • Seong, Hyeon-Kyeong
    • The KIPS Transactions:PartA
    • /
    • v.14A no.2
    • /
    • pp.107-116
    • /
    • 2007
  • In this paper, we present a method on the construction of multiple-valued circuits using Reed-Muller Expansions(RME). First, we discussed the input output interconnection of multiple valued function using Perfect Shuffle techniques and Kronecker product and designed the basic cells of performing the transform matrix and the reverse transform matrix of multiple valued RME using addition circuit and multiplication circuit of GF(4). Using these basic cells and the input-output interconnection technique based on Perfect Shuffle and Kronecker product, we implemented the multiple valued logic circuit based on RME. The proposed design method of multiple valued RME is simple and very efficient to reduce addition circuits and multiplication circuits as compared with other methods for same function because of using matrix transform based on modular structures. The proposed design method of multiple valued logic circuits is simple and regular for wire routing and possess the properties of concurrency and modularity of array.

Study on Construction of Quinternary Logic Circuits Using Perfect Shuffle (Perfect Shuffle에 의한 5치 논리회로의 구성에 관한 연구)

  • Seong, Hyeon-Kyeong
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.15 no.3
    • /
    • pp.613-623
    • /
    • 2011
  • In this paper, we present a method on the construction of quinternary logic circuits using Perfect shuffle. First, we discussed the input-output interconnection of quinternary logic function using Perfect Shuffle techniques and Kronecker product, and designed the basic cells of performing the transform matrix and the reverse transform matrix of quinternary Reed-Muller expansions(QRME) using addition circuit and multiplication circuit of GF(5). Using these basic cells and the input-output interconnection technique based on Perfect Shuffle and Kronecker product, we implemented the quinternary logic circuit based on QRME. The proposed design method of QRME is simple and very efficient to reduce addition circuits and multiplication circuits as compared with other methods for same logic function because of using matrix transform based on modular structures. The proposed design method of quinternary logic circuits is simple and regular for wire routing and possess the properties of concurrency and modularity of array.

A Multi-Compartment Secret Sharing Method (다중 컴파트먼트 비밀공유 기법)

  • Cheolhoon Choi;Minsoo Ryu
    • The Transactions of the Korea Information Processing Society
    • /
    • v.13 no.2
    • /
    • pp.34-40
    • /
    • 2024
  • Secret sharing is a cryptographic technique that involves dividing a secret or a piece of sensitive information into multiple shares or parts, which can significantly increase the confidentiality of a secret. There has been a lot of research on secret sharing for different contexts or situations. Tassa's conjunctive secret sharing method employs polynomial derivatives to facilitate hierarchical secret sharing. However, the use of derivatives introduces several limitations in hierarchical secret sharing. Firstly, only a single group of participants can be created at each level due to the shares being generated from a sole derivative. Secondly, the method can only reconstruct a secret through conjunction, thereby restricting the specification of arbitrary secret reconstruction conditions. Thirdly, Birkhoff interpolation is required, adding complexity compared to the more accessible Lagrange interpolation used in polynomial-based secret sharing. This paper introduces the multi-compartment secret sharing method as a generalization of the conjunctive hierarchical secret sharing. Our proposed method first encrypts a secret using external groups' shares and then generates internal shares for each group by embedding the encrypted secret value in a polynomial. While the polynomial can be reconstructed with the internal shares, the polynomial just provides the encrypted secret, requiring external shares for decryption. This approach enables the creation of multiple participant groups at a single level. It supports the implementation of arbitrary secret reconstruction conditions, as well as conjunction. Furthermore, the use of polynomials allows the application of Lagrange interpolation.

Equivalence Checking Finite State Machines with SAT-Procedure (SAT 프로시져를 이용한 유한 상태 기계의 동치 검사)

  • 엄태호;권기현;김태훈
    • Proceedings of the Korean Information Science Society Conference
    • /
    • 2003.04c
    • /
    • pp.37-39
    • /
    • 2003
  • 본 연구에서는 만족성 검사기를 이용하여 두 유한 상태 기계의 행위가 동치인지를 검사한다. 기존의 동치 검사는 대부분 BDD를 기반으로 했었기 때문에 변수 순서 배열 및 내부 BDD노드 폭발 문제에 시달렸었다. 하지만 여기서는 BDD대신 명제 논리를 이용하기 때문에 위와 같은 문제점을 피할 수 있다. 하지만 논리식을 만족성 검사기의 입력 형태인 논리곱 정규형으로 변환하는 과정에서 절의 3기는 식의 크기에 지수적으로 증가하였다.

  • PDF

Algebraic Kripke-Style Semantics for Weakly Associative Fuzzy Logics (약한 결합 원리를 갖는 퍼지 논리를 위한 대수적 크립키형 의미론)

  • Yang, Eunsuk
    • Korean Journal of Logic
    • /
    • v.21 no.2
    • /
    • pp.155-174
    • /
    • 2018
  • This paper deals with Kripke-style semantics, which will be called algebraic Kripke-style semantics, for weakly associative fuzzy logics. First, we recall algebraic semantics for weakly associative logics. W next introduce algebraic Kripke-style semantics, and also connect them with algebraic semantics.