• Title/Summary/Keyword: Linear complexity

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A Study on the Cryptographic Properties of FCSR Sequences (FCSR 난수열의 암호학적인 특성에 관한 연구)

  • 서창호;김정녀;조현숙;김석우
    • The KIPS Transactions:PartC
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    • v.8C no.1
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    • pp.12-15
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    • 2001
  • A summation generator creates sequence from addition with carry of LFSR (Linear Feedback Shift Register) sequences. Similarly, it is possible to generate keystream by bitwise exclusive-oring on two FCSR sequences. In this paper, we described the cryptographic properties of a sequence generated by the FCSRs.

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Performance Improvement of Korean Connected Digit Recognition Using Various Discriminant Analyses (다양한 변별분석을 통한 한국어 연결숫자 인식 성능향상에 관한 연구)

  • Song Hwa Jeon;Kim Hyung Soon
    • MALSORI
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    • no.44
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    • pp.105-113
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    • 2002
  • In Korean, each digit is monosyllable and some pairs are known to have high confusability, causing performance degradation of connected digit recognition systems. To improve the performance, in this paper, we employ various discriminant analyses (DA) including Linear DA (LDA), Weighted Pairwise Scatter LDA WPS-LDA), Heteroscedastic Discriminant Analysis (HDA), and Maximum Likelihood Linear Transformation (MLLT). We also examine several combinations of various DA for additional performance improvement. Experimental results show that applying any DA mentioned above improves the string accuracy, but the amount of improvement of each DA method varies according to the model complexity or number of mixtures per state. Especially, more than 20% of string error reduction is achieved by applying MLLT after WPS-LDA, compared with the baseline system, when class level of DA is defined as a tied state and 1 mixture per state is used.

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O(logN) Depth Routing Structure Based on truncated Concentrators (잘림구조 집중기에 기초한 O(logN) 깊이의 라우팅 구조)

  • Lee, Jong-Keuk
    • Proceedings of the Korea Multimedia Society Conference
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    • 1998.04a
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    • pp.366-370
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    • 1998
  • One major limitation of the efficiency of parallel computer designs has been the prohibitively high cost of parallel communication between processors and memories. Linear order concentrators can be used to build theoretically optimal interconnection schemes. Current designs call for building superconcentrators from concentrators, then using these to recursively partition the connection streams O(log2N) times to achieve point-to-point routing. Since the superconcentrators each have O(N) hardware complexity but O(log2N) depth, the resulting networks are optimal in hardware, but they are of O(log2N) depth. This pepth is not better than the O(log2N) depth Bitonic sorting networks, which can be implemented on the O(N) shuffle-exchange network with message passing. This paper introduces a new method of constructing networks using linear order concentrators and expanders, which can be used to build interconnection networks with O(log2N) depth as well as O(Nlog2N) hardware cost. (All logarithms are in base 2 throughout paper)

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A WEIGHTED-PATH FOLLOWING INTERIOR-POINT ALGORITHM FOR CARTESIAN P(κ)-LCP OVER SYMMETRIC CONES

  • Mansouri, Hossein;Pirhaji, Mohammad;Zangiabadi, Maryam
    • Communications of the Korean Mathematical Society
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    • v.32 no.3
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    • pp.765-778
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    • 2017
  • Finding an initial feasible solution on the central path is the main difficulty of feasible interior-point methods. Although, some algorithms have been suggested to remedy this difficulty, many practical implementations often do not use perfectly centered starting points. Therefore, it is worth to analyze the case that the starting point is not exactly on the central path. In this paper, we propose a weighted-path following interior-point algorithm for solving the Cartesian $P_{\ast}({\kappa})$-linear complementarity problems (LCPs) over symmetric cones. The convergence analysis of the algorithm is shown and it is proved that the algorithm terminates after at most $O\((1+4{\kappa}){\sqrt{r}}{\log}{\frac{x^0{\diamond}s^0}{\varepsilon}}\)$ iterations.

An Image Contrast Enhancement Method Using Brightness Preseving on the Linear Approximation CDF (선형 추정 CDF에서 밝기 보존을 이용한 이미지 콘트라스트 향상 기법)

  • Cho Hwa-Hyun;Choi Myung-Ryul
    • The KIPS Transactions:PartB
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    • v.11B no.7 s.96
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    • pp.779-784
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    • 2004
  • In this paper, we have proposed an image contrast control method using brightness preserving on the FPD(Flat Panel Display). The proposed method can be easily applied to the FPD required real-time processing, since hardware complexity is greatly reduced using linear approximation method of CDF(Cumulative Density Function). For effective processing of the proposed algorithm, we have utilized the sample value of CDF and Barrel Shift. Visual test and standard deviation of their histogram have been introduced to evaluate the resultant output images of the pro-posed method and the original ones.

Computation of Unsteady Separated Flows Using the Vortex Particle Method (ll) - Stability and Particle Redistribution - (와류입자법에 의한 비정상 박리흐름의 전산 (II) - 안전성과 와류입자 재배열 -)

  • Park, Woe-Chul
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.23 no.10
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    • pp.1223-1228
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    • 1999
  • As part of study on separated flow using the vortex particle method, stability of the method and particle redistribution were scrutinized. Stability was investigated by choosing different combination of numerical parameters. The Gaussian vortex was considered to make the problem simple by eliminating the complexity due to presence of walls. It was shown that the numerical method was stable when $v{\Delta}t/h^2{\leq}0.5$. In all the stable cases the circulation and the linear momentum were conserved. Without the particle redistribution, the angular momentum was severely attenuated.

Clustering Algorithm of Hierarchical Structures in Large-Scale Wireless Sensor and Actuator Networks

  • Quang, Pham Tran Anh;Kim, Dong-Seong
    • Journal of Communications and Networks
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    • v.17 no.5
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    • pp.473-481
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    • 2015
  • In this study, we propose a clustering algorithm to enhance the performance of wireless sensor and actuator networks (WSANs). In each cluster, a multi-level hierarchical structure can be applied to reduce energy consumption. In addition to the cluster head, some nodes can be selected as intermediate nodes (INs). Each IN manages a subcluster that includes its neighbors. INs aggregate data from members in its subcluster, then send them to the cluster head. The selection of intermediate nodes aiming to optimize energy consumption can be considered high computational complexity mixed-integer linear programming. Therefore, a heuristic lowest energy path searching algorithm is proposed to reduce computational time. Moreover, a channel assignment scheme for subclusters is proposed to minimize interference between neighboring subclusters, thereby increasing aggregated throughput. Simulation results confirm that the proposed scheme can prolong network lifetime in WSANs.

A Soft-Decision Decoding Algorithm for Linear Binary Block Codes (線形 2元 블럭 符號를 위한 軟判定 復號 알고리듬)

  • Shim, Yong-Geol;Lee, Choong-Woong
    • Journal of the Korean Institute of Telematics and Electronics
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    • v.27 no.2
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    • pp.9-15
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    • 1990
  • A soft-decision decoding algorithm for linear binary block codes is proposed, for minimizing the block error probability. To compare the proposed algorithm with already established decoding methods, computer simulations are performed for the (7,4)Hamming code and the (23,12) Golay code. The average number of hard-decision decoding is always less then 2, and approaches to 1 when the signal to noise ratio is sufficiently large. These results show that the proposed algorithm reduces the decoding complexity.

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A Divide-and-Conquer Algorithm for Rigging Elections Problem

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.12
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    • pp.101-106
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    • 2015
  • This paper suggests heuristic algorithm with polynomial time complexity for rigging elections problem that can be obtain the optimal solution using linear programming. The proposed algorithm transforms the given problem into adjacency graph. Then, we divide vertices V into two set W and D. The set W contains majority distinct and the set D contains minority area. This algorithm applies divide-and-conquer method that the minority area D is include into majority distinct W. While this algorithm using simple rule, that can be obtains the optimal solution equal to linear programing for experimental data. This paper shows polynomial time solution finding rule potential in rigging elections problem.

Slope variation effect on large deflection of compliant beam using analytical approach

  • Khavaji, A.;Ganji, D.D.;Roshan, N.;Moheimani, R.;Hatami, M.;Hasanpour, A.
    • Structural Engineering and Mechanics
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    • v.44 no.3
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    • pp.405-416
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    • 2012
  • In this study the investigation of large deflections subject in compliant mechanisms is presented using homotopy perturbation method (HPM). The main purpose is to propose a convenient method of solution for the large deflection problem in compliant mechanisms in order to overcome the difficulty and complexity of conventional methods, as well as for the purpose of mathematical modeling and optimization. For simplicity, a cantilever beam of linear elastic material under horizontal, vertical and bending moment end point load is considered. The results show that the applied method is very accurate and capable for cantilever beams and can be used for a large category of practical problems for the aim of optimization. Also the consequence of effective parameters on the large deflection is analyzed and presented.