• Title/Summary/Keyword: Binary search

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Asynchronous Multilevel Search Strategy for Fast Acquisition of AltBOC Signals

  • Kim, Binhee;Kong, Seung-Hyun
    • Journal of Positioning, Navigation, and Timing
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    • v.4 no.4
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    • pp.161-171
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    • 2015
  • Alternative binary offset carrier (AltBOC) signals can be approximated by four synchronized direct sequence spread spectrum (DSSS) signals, each pair of which is a quadrature phase shift keyed (QPSK) signal at a different frequency. Therefore, depending on the strength of an incoming AltBOC signal, an acquisition technique can reduce the mean acquisition time (MAT) by searching the four DSSS signals asynchronously; the search for each of the four DSSS signals can start at one of the evenly separated hypotheses on the two-dimensional hypothesis space. And detection sensitivity can be improved by multiple levels when different numbers of search results for the same hypothesis are combined. In this paper, we propose a fast AltBOC acquisition technique that has an asynchronous search strategy and efficiently utilizes the output of the four search results to increase the sensitivity level when sensitivity improvement is needed. We provide a complete theoretical analysis and demonstrate with numerous Monte Carlo simulations that the MAT of the proposed technique is much smaller than conventional AltBOC acquisition techniques.

Motion Estimation in Video Coding using Search Candidate Point on Region by Binary-Tree Structure (이진트리 구조에 따른 구간별 탐색 후보점을 이용한 비디오 코딩의 움직임 추정)

  • Kwak, Sung-Keun
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.14 no.1
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    • pp.402-410
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    • 2013
  • In this paper, we propose a new fast block matching algorithm for block matching using the temporal and spatially correlation of the video sequence and local statistics of neighboring motion vectors. Since the temporal correlation of the video sequence between the motion vector of current block and the motion vector of previous block. The proposed algorithm determines the location of a better starting point for the search of an exact motion vector using the point of the smallest SAD(sum of absolute difference) value by the predicted motion vectors of neighboring blocks around the same block of the previous frame and the current frame and the predictor candidate point on each division region by binary-tree structure. Experimental results show that the proposed algorithm has the capability to dramatically reduce the search points and computing cost for motion estimation, comparing to fast FS(full search) motion estimation and other fast motion estimation.

Past Anti-Collision Algorithm in Ubiquitous ID System (Ubiquitous ID 시스템에서 고속 충돌 방지 알고리즘)

  • 차재룡;김재현
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.29 no.8A
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    • pp.942-949
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    • 2004
  • This paper proposes and analyzes the anti-collision algorithm in Ubiquitous ID system. We mathematically compares the performance of the proposed algorithm with that of binary search algorithm, slotted binary tree algorithm using time slot, and bit-by-bit binary tree algorithm proposed by Auto-ID center. We also validated analytic results using OPNET simulation. Based on the analytic results, comparing the proposed algorithm with bit-by-bit algorithm which is the best of existing algorithms, the performance of proposed algorithm is about 5% higher when the number of tags is 20, and 100% higher when the number of tags is 200.

A Novel Binary Ant Colony Optimization: Application to the Unit Commitment Problem of Power Systems

  • Jang, Se-Hwan;Roh, Jae-Hyung;Kim, Wook;Sherpa, Tenzi;Kim, Jin-Ho;Park, Jong-Bae
    • Journal of Electrical Engineering and Technology
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    • v.6 no.2
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    • pp.174-181
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    • 2011
  • This paper proposes a novel binary ant colony optimization (NBACO) method. The proposed NBACO is based on the concept and principles of ant colony optimization (ACO), and developed to solve the binary and combinatorial optimization problems. The concept of conventional ACO is similar to Heuristic Dynamic Programming. Thereby ACO has the merit that it can consider all possible solution sets, but also has the demerit that it may need a big memory space and a long execution time to solve a large problem. To reduce this demerit, the NBACO adopts the state probability matrix and the pheromone intensity matrix. And the NBACO presents new updating rule for local and global search. The proposed NBACO is applied to test power systems of up to 100-unit along with 24-hour load demands.

A Real Code Genetic Algorithm for Optimum Design (실수형 Genetic-Algorithm에 의한 최적 설계)

  • 양영순;김기화
    • Computational Structural Engineering
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    • v.8 no.2
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    • pp.123-132
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    • 1995
  • Genetic Algorithms(GA), which are based on the theory of natural evolution, have been evaluated highly for their robust performances. Traditional GA has mostly used binary code for representing design variable. The binary code GA has many difficulties to solve optimization problems with continuous design variables because of its large computer core memory size, inefficiency of its computing time, and its bad performance on local search. In this paper, a real code GA is proposed for dealing with the above problems. So, new crossover and mutation processes of GA are developed to use continuous design variables directly. The results of read code GA are compared with those of binary code GA for several single and multiple objective optimization problems. As a result of comparisons, it is found that the performance of the real code GA is better than that of the binary code GA, and concluded that the real code GA developed here can be used for the general optimization problem.

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An Application of a Binary PSO Algorithm to the Generator Maintenance Scheduling Problem (이진 PSO 알고리즘의 발전기 보수계획문제 적용)

  • Park, Young-Soo;Kim, Jin-Ho
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.56 no.8
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    • pp.1382-1389
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    • 2007
  • This paper presents a new approach for solving the problem of maintenance scheduling of generating units using a binary particle swarm optimization (BPSO). In this paper, we find the optimal solution of the maintenance scheduling of generating units within a specific time horizon using a binary particle swarm optimization algorithm, which is the discrete version of a conventional particle swarm optimization. It is shown that the BPSO method proposed in this paper is effective in obtaining feasible solutions in the maintenance scheduling of generating unit. IEEE reliability test systems(1996) including 32-generators are selected as a sample system for the application of the proposed algorithm. From the result, we can conclude that the BPSO can find the optimal solution of the maintenance scheduling of the generating unit with the desirable degree of accuracy and computation time, compared to other heuristic search algorithm such as genetic algorithms. It is also envisaged that BPSO can be easily implemented for similar optimizations and scheduling problems in power system problems to obtain better solutions and improve convergence performance.

USING TABU SEARCH IN CSPS

  • Gupta, D.K.
    • Journal of applied mathematics & informatics
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    • v.8 no.1
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    • pp.181-197
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    • 2001
  • A heuristic method TABU-CSP using Tabu Search (TS) is described for solving Constraint Satisfaction Problems (CSPs). The method is started with a complete but inconsistent solution of a binary CSP and obtained in prespecified number of iterations either a consistent solution or a near optimal solution with an acceptable number of conflicts. The repair in the solution at each iterative step is done by using two heuristics alternatively. The first heuristic is a min-conflicts heuristic that chooses a variable with the maximum number of conflicts and reassigns it the value which leads to the minimum number of conflicts. If the acceptable solution is not reached after the search continued for a certain number of iterations, the min-conflict heuristic is changed and the variable selected least number of times is chosen for repair. If an acceptable solution is not reached, the method switches back to the min-conflict heuristic and proceeds further. This allowed the method to explore a different region of search space space for the solution as well as to prevent cycling. The demonstration of the method is shown on a toy problem [9]which has no solution. The method is then tested on various randomly generated CSPs with different starting solutions. The performance of the proposed method in terms of the average number of consistency is checked and the average number of conflicts is conflicts is compared with that of the Branch and Bound(BB) method used to obtain the same solution. In almost all cases, the proposed method moves faster to the acceptable solution than BB.

Modification-robust contents based motion picture searching method (변형에 강인한 내용기반 동영상 검색방법)

  • Choi, Gab-Keun;Kim, Soon-Hyob
    • 한국HCI학회:학술대회논문집
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    • 2008.02a
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    • pp.215-217
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    • 2008
  • The most widely used method for searching contents of mot ion picture compares contents by extracted cuts. The cut extract ion methods, such as CHD(Color Histogram Difference) or ECR(Edge Change Ratio), are very weak at modifications such as cropping, resizing and low bit rate. The suggested method uses audio contents for indexing and searching to make search be robust against these modification. Scenes of audio contents are extracted for modification-robust search. And based on these scenes, make spectral powers binary on each frequency bin. in the time-frequency domain. The suggested method shows failure rate less than 1% on the false positive error and the true negative error to the modified(using cropping, clipping, row bit rate, addtive frame) contents.

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TPC-BS: Transmission Power Control based on Binary Search in the Wireless Sensor Networks (TPC-BS: 센서 네트워크에서 이진검색 방법을 이용한 빠른 전송전력 결정 방법)

  • Oh, Seung-Hyun
    • Journal of Korea Multimedia Society
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    • v.14 no.11
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    • pp.1420-1430
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    • 2011
  • This paper proposes a new method to optimize energy consumption in a wireless modem by setting up a transmission power value according to the distance between nodes and circumstance in the MAC layer of IEEE 802.15.4. The proposed method can dynamically find an optimal transmission power range using the binary search scheme and minimize overhead caused by multiple message transmissions when determining the optimal transmission power. The determined transmission power is used for transmitting data packets and can be modified dynamically depending on the changes in a network environment when exchanging data packets and acknowledgement signals. The results of the simulations show 30% reduction in energy consumption while 2.5 times increase in data transmission rate per unit of energy comparing with IEEE 802.15.4 standard.

Application of the New Calibration Algorithm of a Straight-Type Five-Hole Pressure Probe (직선형 5공 압력프로브의 새로운 교정 알고리듬 적용)

  • Kim, Jang-Kweon;Oh, Seok-Hyung
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.32 no.11
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    • pp.863-869
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    • 2008
  • This paper investigated the new calibration algorithm of a straight-type five-hole pressure probe for measuring three-dimensional flow velocity components. This new calibration algorithm was used for velocity data reduction from the calibration map and based on the combination of a look-up, a binary search algorithm and a geometry transformation including the translation and reflection of nodes in a calibration map. The calibration map was expanded up to the application angle, ${\pm}55^{\circ}$ of a probe. This velocity data reduction method showed a perfect performance without any kind of interpolating errors in calculating yaw and pitch angles from the calibration map. Moreover, when it was applied to an actual flow field including a swirling flow, a good result came out on the whole.