• Title/Summary/Keyword: 공간 복잡도

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Computing Longest Common Substrings by Using Suffix Arrays (써픽스 배열을 이용한 최장 공통 부분 스트링 계산)

  • 전정은;박희진;김동규
    • Proceedings of the Korean Information Science Society Conference
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    • 2004.10a
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    • pp.739-741
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    • 2004
  • 최장 공통 부분 스트링이란 주어진 두 개 이상의 스트링에서 가장 길게 일치하는 공통 부분 스트링을 계산하는 문제이다 최장 공통 부분 스트링은 스트링 프로세싱이나 생물정보학 분야에서 널리 사용되고 있는 중요한 문제이지만, 현재까지 연구된 동적 프로그래밍이나 써픽스 트리를 사용한 방법은 저장 공간을 많이 차지하므로 효율적이지 못하다 따라서 적은 저장 공간을 차지하면서도 최장 공통 부분 스트링을 빨리 구할 수 있는 알고리즘이 필요하며, 본 논문에서는 이를 위해 써픽스 배열을 도입하였다. 본 논문에서 제시한 알고리즘은 선형 시간, 공간 복잡도를 가지며, 써픽스 트리의 최하 공통 조상(LCA, Lowest Common Ancestor) 연산이나 써픽스 배열에서 사용하는 그와 비슷한 구간 최소 값 질의(RMQ, Range Minima Query)를 전혀 사용하지 않으므로 매우 효율적이다.

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Color Look-Up Table Design for Gamut Mapping and Color Space Conversion (색역 사상과 색공간 변환을 위한 칼라 참조표 설계)

  • 김윤태;조양호;이호근;하영호
    • Journal of the Institute of Electronics Engineers of Korea SP
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    • v.41 no.2
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    • pp.1-10
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    • 2004
  • This paper proposes the method that design CLUT(color look-up table) simultaneously processing gamut mapping and color space conversion using only CLUT without complex computation. After CLUT is constructed using scanner gamut and printer gamut, the scanner gamut is extended to include original scanner gamut. This extended scanner gamut is used as input CIE $L^{*}$ $a^{*}$ $b^{*}$ values for CLUT. Then CMY values are computed by using gamut mapping. Input RGB image of scanner is converted into CIE $L^{*}$ $a^{*}$ $b^{*}$ by using regression function. CIE $L^{*}$ $a^{*}$ $b^{*}$ values of scanner are converted into CMY values without computation of additional gamut mapping using the proposed CLUT. In the experiments, the proposed method resulted in the similar color difference, but reduced the complexity computation than the direct computing method to process gamut mapping and color space conversion respectively.espectively.ively.

The analysis of parameters and affection(Gamsung) for facial types of Korean females in twenties (한국인 20대 여성 얼굴의 수치 및 감성 구조 분석)

  • 박수진;김한경;한재현;이정원;김종일;송경석;정찬섭
    • Proceedings of the Korean Society for Emotion and Sensibility Conference
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    • 2001.05a
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    • pp.74-81
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    • 2001
  • 얼굴은 내측두(IT: inferotemporal) 영역에 독자적인 처리 공간을 가지고 있는 (Bruce, Desimone, & Gross, 1981; Rolls, 1992) 매우 복잡한 시각 자극이다. 본연구는 이러한 복잡한 얼굴 자극을 구성하고 있는 물리적인 특징들을 추출하여 얼굴을 수치 구조면에서 분석하고 이를 감성 공간과 연결시킬 목적으로 수행되었ㄷ. 이를 위해 본연구에서는 먼저 얼굴 내부에 36개의 특징들 및 특징들 간 관계를 설정하였다. 또한 얼굴 외곽형의 분류를 위해 얼굴 윤곽선 부위에 14개의 특징점을 찍고 코끝에서부터 이들 지점과의 거리를 측정하였다. 사람마다 기본적인 얼굴 14개의 특징점을 찍고 코끝에서부터 이들 지점과의 거리를 측정하였다. 사람마다 기본적인 얼굴 크기가 다르다는 점을 감안하여 이들 특징값들 중 길이값들은 얼굴 좌우폭 또는 얼굴 상하길이를 기주으로 정규화(normalization)되었다. 그런 다음 36개의 얼굴 내부 특징 요소들과 5가지 얼굴 외곽형을 입력값으로 하여 주성분분석(PCA: proncipal component analysis)을 실시하고, 여기서 도출된 다섯 개의 요인점수를 기반으로 5차원 공간을 가정하였다. 이 공간을 대표하는 얼굴을 고루 선정하되 해당 얼굴이 있다고 보기 어려운 영역을 제외하고 평균에 해당하는 얼굴을 추가하여 총 30가지 대표 얼굴 유형을 선정하였다. 선정된 얼굴들에 대해 일차적으로 감성 평가를 실시하여 2차원 감성 공간에 대표 얼굴들을 분포시켰다.

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Type II Optimal Normal Basis Multipliers in GF(2n) (타입 II 최적 정규기저를 갖는 GF(2n)의 곱셈기)

  • Kim, Chang Han;Chang, Nam Su
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.25 no.5
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    • pp.979-984
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    • 2015
  • In this paper, we proposed a Semi-Systolic multiplier of $GF(2^n)$ with Type II optimal Normal Basis. Comparing the complexity of the proposed multiplier with Chiou's multiplier proposed in 2012, it is saved $2n^2+44n+26$ in total transistor numbers and decrease 4 clocks in time delay. This means that, for $GF(2^{333})$ of the field recommended by NIST for ECDSA, the space complexity is 6.4% less and the time complexity of the 2% decrease. In addition, this structure has an advantage as applied to Chiou's method of concurrent error detection and correction in multiplication of $GF(2^n)$.

Characteristic analysis of Modular Multipliers and Squarers for GF($2^m$) (유한 필드 GF($2^m$)상의 모듈러 곱셈기 및 제곱기 특성 분석)

  • 한상덕;김창훈;홍춘표
    • Journal of Korea Society of Industrial Information Systems
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    • v.7 no.5
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    • pp.167-174
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    • 2002
  • This paper analyzes the characteristics of three multipliers and squarers in finite fields GF(2/sup m/) from the point of view of processing time and area complexity. First, we analyze structures of three multipliers and squarers: 1) Systolic array structure, 2), LFSR structure, and 3) CA structure. To make performance analysis, each multiplier and squarer was modeled in VHDL and was synthesized for FPGA implementation. The simulation results show that CA structure is the best from the point view of processing time, and LFSR structure is the best from the point of view of area complexity.

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A Comparative Study on Reliability Enhancement Techniques of Soft Output in MIMO Systems (MIMO 시스템을 위한 연판정 값의 신뢰도 향상기법들의 비교분석)

  • Kim, Jae-kwon
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.6 no.4
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    • pp.255-261
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    • 2013
  • In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.

A Comparative Study on Reliability Enhancement Techniques of Soft Output in MIMO Systems (MIMO 시스템을 위한 연판정 값의 신뢰도 향상기법들의 비교분석)

  • Hur, Hoon;Kim, Jae-Kwon
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.1 no.1
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    • pp.53-59
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    • 2008
  • In this paper, we compare two methods that improve the reliability of soft output at the receiver of MIMO communications. The receiver complexity of spatially mutiplexed MIMO system is in proportion to the number of candidate vectors. Low complexity receiver techniques involving a small number of candidate vectors, provide soft output values of low reliability. In order to improve the low reliability of soft output, two previous methods can be used; the first method involves a clipping threshold, the second method uses Euclidian distance instead of squared Euclidian distance. In the paper, we address the theoretical similarity of the two methods, then we compare the two methods from the perspective of hardware implementation.

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Parallel Modular Multiplication Algorithm to Improve Time and Space Complexity in Residue Number System (RNS상에서 시간 및 공간 복잡도 향상을 위한 병렬 모듈러 곱셈 알고리즘)

  • 박희주;김현성
    • Journal of KIISE:Computer Systems and Theory
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    • v.30 no.9
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    • pp.454-460
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    • 2003
  • In this paper, we present a novel method of parallelization of the modular multiplication algorithm to improve time and space complexity on RNS (Residue Number System). The parallel algorithm executes modular reduction using new table lookup based reduction method. MRS (Mixed Radix number System) is used because algebraic comparison is difficult in RNS which has a non-weighted number representation. Conversion from residue number system to certain MRS is relatively fast in residue computer. Therefore magnitude comparison is easily Performed on MRS. By the analysis of the algorithm, it is known that it requires only 1/2 table size than previous approach. And it requires 0(ι) arithmetic operations using 2ㅣ processors.

Reduced Complexity Scheduling Method with MIMO Interference Alignment for Mutually Interfering Broadcast Channels (상호 간섭 Broadcast 채널을 위한 MIMO 간섭 정렬을 이용한 복잡도를 줄인 스케쥴링)

  • Park, Hae-Wook;Park, Seok-Hwan;Sung, Hak-Jea;Lee, In-Kyu
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.37 no.8A
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    • pp.601-611
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    • 2012
  • In this paper, we first study the spatial multiplexing gain for the 3-cell interfering broadcast channels (IFBC) where all base stations and mobile users are equipped with multiple antennas. Then, we present the IA scheme in conjunction with user selection which outperforms the TDMA technique in the IFBC environment. The optimal scheduling method utilizes multiuser diversity to achieve a significant fraction of sum capacity by using an exhaustive search algorithm. To reduce the computational complexity, a suboptimal scheduling method is proposed based on a coordinate ascent approach.

A Study on Adaptive Partitioning-based Genetic Algorithms and Its Applications (적응 분할법에 기반한 유전 알고리즘 및 그 응용에 관한 연구)

  • Han, Chang-Wook
    • Journal of the Institute of Convergence Signal Processing
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    • v.13 no.4
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    • pp.207-210
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    • 2012
  • Genetic algorithms(GA) are well known and very popular stochastic optimization algorithm. Although, GA is very powerful method to find the global optimum, it has some drawbacks, for example, premature convergence to local optima, slow convergence speed to global optimum. To enhance the performance of GA, this paper proposes an adaptive partitioning-based genetic algorithm. The partitioning method, which enables GA to find a solution very effectively, adaptively divides the search space into promising sub-spaces to reduce the complexity of optimization. This partitioning method is more effective as the complexity of the search space is increasing. The validity of the proposed method is confirmed by applying it to several bench mark test function examples and the optimization of fuzzy controller for the control of an inverted pendulum.