• Title/Summary/Keyword: Polynomial Time Algorithm

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An Efficient Architecture for Modified Karatsuba-Ofman Algorithm (불필요한 연산이 없는 카라슈바 알고리즘과 하드웨어 구조)

  • Chang Nam-Su;Kim Chang-Han
    • Journal of the Institute of Electronics Engineers of Korea SD
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    • v.43 no.3 s.345
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    • pp.33-39
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    • 2006
  • In this paper we propose the Modified Karatsuba-Ofman algorithm for polynomial multiplication to polynomials of arbitrary degree. Leone proposed optimal stop condition for iteration of Karatsuba-Ofman algorithm(KO). In this paper, we propose a Non-Redundant Karatsuba-Ofman algorithm (NRKOA) with removing redundancy operations, and design a parallel hardware architecture based on the proposed algorithm. Comparing with existing related Karatsuba architectures with the same time complexity, the proposed architecture reduces the area complexity. Furthermore, the space complexity of the proposed multiplier is reduced by 43% in the best case.

An improved ellipsoid algorithm for LMI feasibility problems (LMI 가능성 문제를 위한 타원 알고리즘의 개선)

  • Bahng, Dane;Choi, Jin-Young
    • Proceedings of the KIEE Conference
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    • 2002.11c
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    • pp.188-192
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    • 2002
  • The ellipsoid algorithm solves some feasibility(or optimization) problems with LMI(Linear Matrix Inequality) constraint in polynomial time. Recently, it has been replaced by interior point algorithm due to its slow convergence and incapability of verifying feasibility. This paper proposes a method to improve its convergence by using the deep-cut method of linear programming. Simulation results show that the improved algorithm is more effective than the original one.

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Linear Time Algorithm for Network Reliability Problem

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.5
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    • pp.73-77
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    • 2016
  • This paper deals with the network reliability problem that decides the communication line between main two districts while the k districts were destroyed in military communication network that the n communication lines are connected in m districts. For this problem, there is only in used the mathematical approach as linear programming (LP) software package and has been unknown the polynomial time algorithm. In this paper we suggest the heuristic algorithm with O(n) linear time complexity to solve the optimal solution for this problem. This paper suggests the flow path algorithm (FPA) and level path algorithm (LPA). The FPA is to search the maximum number of distinct paths between two districts. The LPA is to construct the levels and delete the unnecessary nodes and edges. The proposed algorithm can be get the same optimal solution as LP for experimental data.

An Evolutionary Algorithm for Minimizing the Assembly Time of surface Mounting Machines (표면실장기의 조립시간 최소화를 위한 진화 알고리즘)

  • Lee, Sung-Han;Lee, Young-Dae;Lee, Won-Sik;Lee, Beom-Hee
    • Journal of Institute of Control, Robotics and Systems
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    • v.6 no.8
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    • pp.697-702
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    • 2000
  • The paper considers the problem of improving the productivity of surface mounting in the printed circuit board(PCB) assembly line. This problem is generally divided into two problems ; real assignment problem and pick-and -place sequencing problem which are known to have no polynomial time algorithms. In the last ten years algorithm designers have been trying to solve them separately. However they need to be solved jointly because they are highly interrelated. This paper proposes an evolutionary algorithm which can consider the two problems jointly and thus yield a better solution. In order to evaluate the proposed algorithm computer simulation is performed on real-life surface mounting machines. The proposed algorithm is expected to reduce the assembly time of surface mounting machines and thus improve the productivity.

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A Degree-Constrained Minimum Spanning Tree Algorithm Using k-opt (k-opt를 적용한 차수 제약 최소신장트리 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.5
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    • pp.31-39
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    • 2015
  • The degree-constrained minimum spanning tree (d-MST) problem is considered NP-complete for no exact solution-yielding polynomial algorithm has been proposed to. One thus has to resort to an heuristic approximate algorithm to obtain an optimal solution to this problem. This paper therefore presents a polynomial time algorithm which obtains an intial solution to the d-MST with the help of Kruskal's algorithm and performs k-opt on the initial solution obtained so as to derive the final optimal solution. When tested on 4 graphs, the algorithm has successfully obtained the optimal solutions.

The Minimum number of Mobile Guards Algorithm for Art Gallery Problem (화랑 문제의 최소 이동 경비원 수 알고리즘)

  • Lee, Sang-Un;Choi, Myeong-Bok
    • The Journal of the Institute of Internet, Broadcasting and Communication
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    • v.12 no.3
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    • pp.63-69
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    • 2012
  • Given art gallery P with n vertices, the maximum (sufficient) number of mobile guards is${\lfloor}n/4{\rfloor}$ for simple polygon and${\lfloor}(3n+4)/16{\rfloor}$ for simple orthogonal polygon. However, there is no polynomial time algorithm for minimum number of mobile guards. This paper suggests polynomial time algorithm for the minimum number of mobile guards. Firstly, we obtain the visibility graph which is connected all edges if two vertices can be visible each other. Secondly, we select vertex u with ${\Delta}(G)$ and v with ${\Delta}(G)$ in $N_G(u)$ and delete visible edges from u,v and incident edges. Thirdly, we select $w_i$ in partial graphs and select edges that is the position of mobile guards. This algorithm applies various art galley problems with simple polygons and orthogonal polygons art gallery. As a results, the running time of proposed algorithm is linear time complexity and can be obtain the minimum number of mobile guards.

Maximum Sugar Loss Lot First Production Algorithm for Cane Sugar Production Problem (사탕수수 설탕 생산 문제의 최대 당분 손실 로트 우선 생산 알고리즘)

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.19 no.12
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    • pp.171-175
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    • 2014
  • Gu$\acute{e}$ret et al. tries to obtain the solution using linear programming with $O(m^4)$ time complexity for cane sugar production problem a kind of bin packing problem that is classified as NP-complete problem. On the other hand, this paper suggests the maximum loss of lot first production greedy rule algorithm with O(mlogm) polynomial time complexity underlying assumption of the polynomial time rule to find the solution is exist. The proposed algorithm sorts the lots of sugar loss slope into descending order. Then, we select the lots for each slot production capacity only, and swap the exhausted life span of lots for lastly selected lots. As a result of experiments, this algorithm reduces the $O(m^4)$ of linear programming to O(mlogm) time complexity. Also, this algorithm better result than linear programming.

An Assignment-Balance-Optimization Algorithm for Minimizing Production Cycle Time of a Printed Circuit Board Assembly Line

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.2
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    • pp.97-103
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    • 2016
  • This paper deals with the cycle time minimization problem that determines the productivity in printed circuit board (PCB) with n components using the m placement machines. This is known as production cycle time determination problem (PCTDP). The polynomial time algorithm to be obtain the optimal solution has been unknown yet, therefore this hard problem classified by NP-complete. This paper gets the initial assignment result with the machine has minimum unit placement time per each component firstly. Then, the balancing process with reallocation from overhead machine to underhead machine. Finally, we perform the swap optimization and get the optimal solution of cycle time $T^*$ within O(mn) computational complexity. For experimental data, the proposed algorithm can be obtain the same result as integer programming+branch-and-bound (IP+B&B) and B&B.

Maximum Options-Equiped Class First-Production Algorithm for Car Sequencing Problem

  • Lee, Sang-Un
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.9
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    • pp.105-111
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    • 2015
  • This paper suggests O(n) linear-time algorithm for car sequencing problem (CSP) that has been classified as NP-complete because of the polynomial-time algorithm to solve the solution has been unknown yet. This algorithm applies maximum options-equiped car type first production rule to decide the car sequencing of n meet the r:s constraint. This paper verifies thirteen experimental data with the six data are infeasible. For thirteen experimental data, the proposed algorithm can be get the solution for in all cases. And to conclude, This algorithm shows that the CSP is not NP-complete but the P-problem. Also, this algorithm proposes the solving method to the known infeasible cases. Therefore, the proposed algorithm will stand car industrial area in good stead when it comes to finding a car sequencing plan.

Cell Formation Considering the Minimization of Manufacturing Leadtime in Cellular Manufacturing Systems (셀룰러 생산시스템에서 생산 리드타임의 최소화를 고려한 셀 구성 방법)

  • Yim, Dong-Soon;Woo, Hoon-Shik
    • Journal of Korean Institute of Industrial Engineers
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    • v.30 no.4
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    • pp.285-293
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    • 2004
  • In this study, a machine grouping problem for the formation of manufacturing cells is considered. We constructed the problem as minimizing manufacturing leadtime consisting of parts' processing, moving, and waiting time. Specifically, the main objective of the defined problem is established as minimizing inter-cell traffic in order to minimize the part's moving time. In addition, to reduce the waiting time of parts, the load balance among cells is implicitly included as constraints. Since this problem is well known as NP-complete and cannot be solved in polynomial time, a genetic algorithm is implemented to obtain solutions. Also, a local optimization algorithm is applied in order to improve the solution by the genetic algorithm. Several experiments show that the suggested algorithms guarantee near optimal solutions in a few seconds.