• Title/Summary/Keyword: computational algorithm

Search Result 4,372, Processing Time 0.032 seconds

Efficient power allocation algorithm in downlink cognitive radio networks

  • Abdulghafoor, Omar;Shaat, Musbah;Shayea, Ibraheem;Mahmood, Farhad E.;Nordin, Rosdiadee;Lwas, Ali Khadim
    • ETRI Journal
    • /
    • v.44 no.3
    • /
    • pp.400-412
    • /
    • 2022
  • In cognitive radio networks (CRNs), the computational complexity of resource allocation algorithms is a significant problem that must be addressed. However, the high computational complexity of the optimal solution for tackling resource allocation in CRNs makes it inappropriate for use in practical applications. Therefore, this study proposes a power-based pricing algorithm (PPA) primarily to reduce the computational complexity in downlink CRN scenarios while restricting the interference to primary users to permissible levels. A two-stage approach reduces the computational complexity of the proposed mathematical model. Stage 1 assigns subcarriers to the CRN's users, while the utility function in Stage 2 incorporates a pricing method to provide a power algorithm with enhanced reliability. The PPA's performance is simulated and tested for orthogonal frequency-division multiplexing-based CRNs. The results confirm that the proposed algorithm's performance is close to that of the optimal algorithm, albeit with lower computational complexity of O(M log(M)).

AN ALGORITHM FOR GENERATING MINIMAL CUTSETS OF UNDIRECTED GRAPHS

  • Shin, Yong-Yeonp;Koh, Jai-Sang
    • Journal of applied mathematics & informatics
    • /
    • v.5 no.3
    • /
    • pp.771-784
    • /
    • 1998
  • In this paper we propose an algorithm for generating minimal cutsets of undirected graphs. The algorithm is based on a blocking mechanism for generating every minimal cutest ex-actly once. The algorithm has an advantage of not requiring any preliminary steps to find minimal cutsets. The algorithm generates minimal cutsets at O(e.n) {where e,n = number of (edges, vertices) in the graph} computational effort per cutset. Formal proofs of the algorithm are presented.

Fast Detection of Copy Move Image using Four Step Search Algorithm

  • Shin, Yong-Dal;Cho, Yong-Suk
    • Journal of Korea Multimedia Society
    • /
    • v.21 no.3
    • /
    • pp.342-347
    • /
    • 2018
  • We proposed a fast detection of copy-move image forgery using four step search algorithm in the spatial domain. In the four-step search algorithm, the search area is 21 (-10 ~ +10), and the number of pixels to be scanned is 33. Our algorithm reduced computational complexity more than conventional copy move image forgery methods. The proposed method reduced 92.34 % of computational complexity compare to exhaustive search algorithm.

Diffusive DTW Algorithm for Optimizing Distance Matrix Computation Structure (거리 행렬 연산 구조 최적화를 위한 확산 동적 시간 왜곡(Diffusive DTW) 알고리즘)

  • Kim, Young-tak;Jin, Kyo-hong
    • Proceedings of the Korean Institute of Information and Commucation Sciences Conference
    • /
    • 2022.10a
    • /
    • pp.93-96
    • /
    • 2022
  • DTW can eliminate gaps between sequences of different lengths and find out the similarity of patterns, but due to the time and space complexity, it requires a high computational cost on large datasets. In this paper, we propose a DDTW algorithm that not only reduces computational costs but also has no error in the results. In addition, the algorithm complexity of DTW and DDTW is compared by measuring the computational time according to the length of the sequence. Simulation results show a noticeable reduction in computational time in DDTW compared to DTW.

  • PDF

An efficient procedure for lightweight optimal design of composite laminated beams

  • Ho-Huu, V.;Vo-Duy, T.;Duong-Gia, D.;Nguyen-Thoi, T.
    • Steel and Composite Structures
    • /
    • v.27 no.3
    • /
    • pp.297-310
    • /
    • 2018
  • A simple and efficient numerical optimization approach for the lightweight optimal design of composite laminated beams is presented in this paper. The proposed procedure is a combination between the finite element method (FEM) and a global optimization algorithm developed recently, namely Jaya. In the present procedure, the advantages of FEM and Jaya are exploited, where FEM is used to analyze the behavior of beam, and Jaya is modified and applied to solve formed optimization problems. In the optimization problems, the objective aims to minimize the overall weight of beam; and fiber volume fractions, thicknesses and fiber orientation angles of layers are selected as design variables. The constraints include the restriction on the first fundamental frequency and the boundaries of design variables. Several numerical examples with different design scenarios are executed. The influence of the design variable types and the boundary conditions of beam on the optimal results is investigated. Moreover, the performance of Jaya is compared with that of the well-known methods, viz. differential evolution (DE), genetic algorithm (GA), and particle swarm optimization (PSO). The obtained results reveal that the proposed approach is efficient and provides better solutions than those acquired by the compared methods.

A Reduction Algorithm of Computational Amount using Adjustment the Not Uniform Interval and Distribution Characteristic of LSP (불균등 간격조절과 선형 스펙트럼 쌍 분포특성을 이용한 계산량 단축 알고리즘)

  • Ju, Sang-Gyu
    • Proceedings of the KAIS Fall Conference
    • /
    • 2010.05a
    • /
    • pp.261-264
    • /
    • 2010
  • Fast algorithm is proposed by using mel scale and the distribution characteristic of LSP parameters, and is to reduce the computational amount. Computational amount means the calculating times of transformation from LPC coefficients to LSP parameters. Among conventional methods, the real root method is considerably simpler than other, but neverthless, it still suffer from its indeterministic computational time. Because the root searching is processed sequentially in frequency region. In this paper, the searching interval is arranged by using mel scale but not it is uniform and searching order is arranged by the distribution characteristic of LSP parameters that is most LSP papameters are occured in specific frequency region. In experimental results, computational amount of the proposed algorithm is reduced about 48.95% in average, but the transformed LSP parameters of the proposed method were the same as those of real root method.

  • PDF

Low Computational Algorithm of Soft-Decision Extended BCH Decoding Algorithm for Next Generation DVB-RCS Systems (차세대 DVB-RCS 시스템을 위한 저 계산량 연판정 e-BCH 복호 알고리즘)

  • Park, Tae-Doo;Kim, Min-Hyuk;Lim, Byeong-Su;Jung, Ji-Won
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
    • /
    • v.22 no.7
    • /
    • pp.705-710
    • /
    • 2011
  • In this paper, we proposed the low computational complexity soft-decision e-BCH decoding algorithm based on the Chase algorithm. In order to make the test patterns, it is necessary to re-order the least reliable received symbols. In the process of ordering and finding optimal decoding symbols, high computational complexity is required. Therefore, this paper proposes the method of low computational complexity algorithm for soft-decision e-BCH decoding process.

A fast running FIR Filter structure reducing computational complexity

  • Lee, Jae-Kyun;Lee, Chae-Wook
    • Proceedings of the Korea Society of Information Technology Applications Conference
    • /
    • 2005.11a
    • /
    • pp.45-48
    • /
    • 2005
  • In this paper, we propose a new fast running FIR filter structure that improves the convergence speed of adaptive signal processing and reduces the computational complexity. The proposed filter is applied to wavelet based adaptive algorithm. Actually we compared the performance of the proposed algorithm with other algorithm using computer simulation of adaptive noise canceler based on synthesis speech. As the result, We know the proposed algorithm is prefer than the existent algorithm.

  • PDF

A COOLEY-TUKEY MODIFIED ALGORITHM IN FAST FOURIER TRANSFORM

  • Kim, HwaJoon;Lekcharoen, Somchai
    • Korean Journal of Mathematics
    • /
    • v.19 no.3
    • /
    • pp.243-253
    • /
    • 2011
  • We would like to propose a Cooley-Tukey modied algorithm in fast Fourier transform(FFT). Of course, this is a kind of Cooley-Tukey twiddle factor algorithm and we focused on the choice of integers. The proposed algorithm is better than existing ones in speeding up the calculation of the FFT.

Hexahedral Mesh Generation by Sweeping and Grafting Algorithm (스위핑과 접목 알고리즘은 이용한 육면체 요소망의 생성)

  • 권기연;채수원
    • Korean Journal of Computational Design and Engineering
    • /
    • v.6 no.2
    • /
    • pp.125-132
    • /
    • 2001
  • An algorithm for generating all hexahedral meshes for three dimensional objects has been presented. This algorithm is based on the sweeping and the grafting method. In sweeping process internal nodes generating method has been modified by employing the distances between nodes on connecting surfaces and on source surfaces. In addition to the sweeping processes grafting algorithm is also modified to obtain more effective meshes by refining elements near grafting surfaces. With this method two and a half dimensional hexahedral meshes for three dimensional objects can be generated effectively. Sample meshes are constructed to demonstrate the mesh generating capability of the proposed algorithm.

  • PDF