• 한국통신학회논문지
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• 제29권12C호
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• pp.1623-1632
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• 2004

본 논문에서는 전형적인 실내 무선 채널 환경에서 초광대역 (Ultra Wide Band; UWB) 신호의 고속 동기 획득을 위한 Single-Dwell 연속 통기 탐색 기반의 Linear 탐색 알고리즘 및 Bit Reversal 탐색 알고리즘에 대한 성능분석을 수행하였다. IEEE 802.15 Task Group 3a UWB 실내 무선 채널 환경에서 프레임 구간 및 탐색 단위 구간 등의 변화에 따른 모의실험 결과. Linear 탐색 알고리즘보다 Bit Reversal 탐색 알고리즘이 정규화된 평균 동기 획득 소요 시간에 대해 단연 우수함을 확인하였으며, 탐색 종료 구간의 범위 변화에 따른 정규화된 평균 동기 획득 소요 시간이 이상적인 경우와 거의 일치함을 확인하였다. 특히, Bit Reversal 탐색 알고리즘의 경우 탐색 단위 구간이 세밀할수록 동일한 소요 시간에 대해 더욱 정확한 동기 획득 성능을 얻음을 확인할 수 있었다.

• 한국멀티미디어학회논문지
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• 제18권4호
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• pp.437-442
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• 2015

Voice activity detection is very important process that voice activity separated form noisy speech signal for speech enhance. Over the past few years, many studies have been made on voice activity detection, but it has poor performance in low signal to noise ratio environment or fickle noise such as car noise. In this paper, it proposed new voice activity detection algorithm using ensemble variance based on wavelet band entropy and soft thresholding method. We conduct a survey in a lot of signal to noise ratio environment of car noise to evaluate performance of the proposed algorithm and confirmed performance of the proposed algorithm.

• 대한산업공학회지
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• 제34권2호
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• pp.205-215
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• 2008

convergence networks (BcN). The problem seeks to minimize the total cost of switch and cable while satisfying the requirement of demand and quality of service (QoS). We develop mixed integer programming models to obtain the optimal switch location of the access network. We develop a Tabu Search (TS) heuristic algorithm for finding a good feasible solution within a reasonable time limit. We propose real networks with up to 25 nodes and 180 demands. In order to demonstrate the effectiveness of the proposed algorithm, we generate lower bounds from nonlinear QoS relaxation problem. Computational results show that the proposed heuristic algorithm provides upper bounds within 5% optimality gap in 10 seconds.

• Journal of Forest and Environmental Science
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• 제34권2호
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• pp.142-144
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• 2018

This paper discusses the development of semi-automatic search program for crown delineation in stand level. The crown of an individual tree was delineated by applying the Watershed (WS) and Valley Following (VF) algorithms. Unmanned Aerial Vehicle (UAV) images were used in the semi-automatic search program to delineate the crown area. The overall accuracy and Khat were used in accuracy assessment. WS algorithm's model showed the overall accuracy and Khat index of 0.80 and 0.59, respectively, in Plot 1. However, the overall accuracy and Khat of VF algorithm's model were 0.78 and 0.51, respectively, in Plot 2.

• 전자공학회논문지C
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• 제34C권10호
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• pp.36-42
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• 1997

In the whole world, the research about the VLSI implementation of motion estimation algorithm is progressed to actively full (brute force) search algorithm research with the development of systolic array possible to parallel and pipeline processing. But, because of processing time's limit in a field to handle a huge data quantily such as a high definition television, many problems are happened to full search algorithm. In the paper, as a fast processing to using parallel scheme for the serial input image data, motion estimator of systolic array structure verifying that processing time is improved in contrast to the conventional full search algorithm.

• 대한전자공학회:학술대회논문집
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• 대한전자공학회 2003년도 하계종합학술대회 논문집 I
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• pp.274-277
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• 2003

Millimeter-wave networking is composed of narrow beam link. High directivity of the beam provides either advantage or disadvantage in comparison with conventional wide-lobe microwave communications. In such networks, it is very substantial that beam connecting point to point is fixed in right direction. It is major requirement in the beam network to keep the beam in best direction. In this paper, We propose the method to find a best suited direction of the antenna's beam using the Genetic Algorithm in point-to-point link. Proposed method presume that each station knows his direction $\theta$$_1$,$\theta$$_2$ at every step of Genetic Algorithm, then it can be expected that GA is possible to search the ideal solution. Intensity of the received signal is evaluated by the multiplication of lengths to the point which the lobe meets with the horizontal line.

• 전자공학회논문지C
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• 제35C권1호
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• pp.25-33
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• 1998

This paepr presents an algorithm for searching an object in a fast way which contains a continuous moving object in multi-dimensional spatical databases. This algorithm improves the search method of R-tree for the case that a target object is continuously moving in a spatial database. It starts the searching from the current node instead of the root of R-tree. Thus, the algorithm will find the target object from the entries of current node or sibling nodes in the most cases. The performance analysis shows that it is more efficient than the existing algorithm for R-tree when search windows or target objects are continuously moving.

• 산업경영시스템학회지
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• 제23권61호
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• pp.105-114
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• 2000

Job Shop Problem which consists of the m different machines and n jobs is a NP-hard problem of the combinatorial optimization. Each job consists of a chain of operations, each of which needs to be processed during an uninterrupted time period of a given length on a given machine. Each machine can process at most one operation at a time. The purpose of this paper is to develop the heuristic method to solve large scale scheduling problem using Constraint Satisfaction Problem method and Simulated Annealing. The proposed heuristic method consists of the search algorithm and optimization algorithm. The search algorithm is to find the solution in the solution space using CSP concept such as backtracking and domain reduction. The optimization algorithm is to search the optimal solution using SA. This method is applied to MT06, MT10 and MT20 Job Shop Problem, and compared with other heuristic method.

• 조명전기설비학회논문지
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• 제28권8호
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• pp.47-53
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• 2014

This paper presents an Differential Search(DS) Algorithm for solving the economic load dispatch(ELD) problems with Valve-Point loading constraints. DS algorithm simulates the Brownian-like random-walk movement used by an organism to migrate. Numerical results on a test system consisting of 13 units show that the proposed approach is faster, more robust and powerful than conventional algorithms. Case studies show the simulation results are better than Lagrange method, the Hopfield neural networks and GA.

• Structural Engineering and Mechanics
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• 제60권4호
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• pp.729-747
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• 2016

This study aims to present a novel optimization algorithm known as gravitational search algorithm (GSA) for structural damage detection. An objective function for damage detection is established based on structural vibration data in frequency domain, i.e., natural frequencies and mode shapes. The feasibility and efficiency of the GSA are testified on three different structures, i.e., a beam, a truss and a plate. Results show that the proposed strategy is efficient for determining the locations and the extents of structural damages using the first several modal data of the structure. Multiple damages cases in different types of structures are studied and good identification results can be obtained. The effect of measurement noise on the identification results is investigated.