• Steel and Composite Structures
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• 제9권6호
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• pp.535-555
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• 2009

The harmony search method based optimum design algorithm is presented for geometrically non-linear semi-rigid steel frames. Harmony search method is recently developed metaheuristic algorithm which simulates the process of producing a musical performance. The optimum design algorithm aims at obtaining minimum weight steel frames by selecting from standard set of steel sections such as European wide flange beams (HE sections). Strength constraints of Turkish Building Code for Steel Structures (TS648) specification and displacement constraints were used in the optimum design formulation. The optimum design algorithm takes into account both the geometric non-linearity of the frame members and the semi-rigid behaviour of the beam-to-column connections. The Frye-Morris polynomial model is used to calculate the moment-rotation relation of beam-to-column connections. The robustness of harmony search algorithm, in comparison with genetic algorithms, is verified with two benchmark examples. The comparisons revealed that the harmony search algorithm yielded not only minimum weight steel frames but also required less computational effort for the presented examples.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 2003년도 ICCAS
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• pp.1763-1766
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• 2003

Millimeter-wave networking is composed of narrow beam link. 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 (GA) in point-to-point link. Proposed method presume that each station knows his direction ${\theta}_1$ , ${\theta}_2$ at every step of GA, 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.

• KSII Transactions on Internet and Information Systems (TIIS)
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• 제15권5호
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• pp.1929-1943
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• 2021

Millimeter wave (mmWave) communication based on the wide bandwidth of >28 GHz is one of the key technologies for cellular-connected unmanned aerial vehicles (UAVs). The selection of mmWave beams in such cellular-connected UAVs is challenging and critical, especially when downlink transmissions toward aerial user equipment (UE) suffer from poor signal-to-interference-plus-noise ratio (SINR) more often than their terrestrial counterparts. This study proposed a coordinated mmWave beam selection scheme using fingerprint for cellular-connected UAV. The scheme comprises fingerprint database configuration and coordinated beam selection. In the fingerprint database configuration, the best beam index from the serving cell and interference beam indexes from neighboring cells are stored. In the coordinated beam selection, the best and interference beams are determined using the fingerprint database information instead of performing an exhaustive search, and the coordinated beam transmission improves the SINR for aerial UEs. System-level simulations assess the UAV effect based on the third-generation partnership project-new radio mmWave and UAV channel models. Simulation results show that the proposed scheme can reduce the overhead of exhaustive search and improve the SINR and spectral efficiency.

• 한국음향학회지
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• 제18권1호
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• pp.53-60
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• 1999

이 논문은 한국 방송 음성 인식에 관한 연구이다. 여기서 우리는 대규모 어휘를 갖는 연속 음성 인식을 위한 방법을 제시한다. 주요 관점은 언어 모델과 탐색 방법이다. 사용된 음성 모델은 기본음소 Semi-continuous HMM이고 언어 모델은 N-gram 방법이다. 탐색 방법은 음성과 언어 정보를 최대한 활용하기 위해 3단계의 방법을 사용하였다. 첫째로, 단어의 끝 부분과 그에 관련된 정보를 만들기 위한 순방향 Viterbi Beam탐색을 하였으며, 둘째로 단어 의 시작 부분과 그에 관련된 정보를 만드는 역방향 Viterbi Beam탐색, 그리고 마지막으로 이들 두 결과와 확률적인 언어 모델을 결합하여 최종 인식결과를 얻기 위해 A/sup */ 탐색을 한다. 이 방법을 사용하여 12,000개의 단어에 대한 화자 독립으로 최고 96.0%의 단어 인식률과 99.2%의 음절 인식률을 얻었다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2008년도 정기 학술대회
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• pp.139-144
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• 2008

In this study, damage detection method using harmony search method and frequency response is proposed. In order to verify this method, the following approaches are implemented. Firstly, damage detection method using harmony search is developed. To detect damage, objective function that minimize difference with natural frequency and modal strain energy from undamaged and damaged model is used. Secondly, finite element model for beam structure is created. And damage scenario is determined. Lastly, damage detection is performed by proposed method and utility of proposed method is verified.

• 대한전기학회논문지:시스템및제어부문D
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• 제54권10호
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• pp.581-586
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• 2005

The multi-beam side scan sonar system uses the towfish installed sonars, it is an equipment that search images of the bottom surface of the sea in real time. It is a typical equipment that is related to a sea investigation such as a geological survey, seabed communication cable and power line cable placing repair investigation, fish breeding ground investigation, sea purification, relic and mineral investigation, and mine and submarine search. Recently, it is used to sea purification and geological survey that require information of the correct surface of the seabed. Therefore, this research develops multi-beam sensors for a side scan sonar that supply various information with the fast scan speed and correct high resolution that is not a simple underwater investigation equipment.

• 제어로봇시스템학회:학술대회논문집
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• 제어로봇시스템학회 1996년도 한국자동제어학술회의논문집(국내학술편); 포항공과대학교, 포항; 24-26 Oct. 1996
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• pp.968-971
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• 1996

In this paper, feedback controller is designed for ball-beam system using genetic algorithms. A genetic algorithms are implemented for optimizing gain parameters of feedback controller. We can find optimal point in multi-dimensional search space by using genetic algorithms. Performance of controller is tested by simulation of ball-beam system.

• 한국전자파학회논문지
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• 제23권6호
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• pp.740-747
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• 2012

최신의 다목적 전투기에 필수적으로 장착되고 있는 능동 위상 배열 레이더(AESA radar, Active Electronically Scanned Array radar)는 스캔 손실(scan loss)로 인해 빔 조향각별 탐지 거리가 불균일하게 나타난다. 빔 조향각별 드웰 시간(dwell time)을 가변함으로써 스캔 손실을 보상할 수 있는 방식이 제시되어 왔으나, 한정된 자원 속에 탐색, 추적, 미사일 유도 등의 다기능을 수행해야 하는 전투기 사격 통제 레이더에서 이러한 방식의 효용성은 종합적인 측면에서 고려되어야 한다. 본 논문에서는 먼저 빔 조향각별 드웰 시간을 가변함으로써, 능동 위상 배열 레이더의 전 탐색 영역에서 균일한 탐색 성능을 도출하였다. 다음으로 고정된 프레임 시간(frame time) 안에 빔 조향각별 드웰 시간을 가변하지 않을 경우의 탐색 부하를 50 %로 가정하면, 균일한 탐색 성능을 위해서는 약 100 %의 시간 자원을 탐색 업무에 할당함으로써, 다기능을 수행해야 하는 전투기 사격 통제 레이더의 요구사항을 만족하지 못함을 나타내었다. 다른 한편으로 균일한 탐색 성능과 50 %의 탐색 부하를 나타내기 위해 프레임 시간을 증가할 경우, 탐색 성능이 기존 대비 86.7 % 저하됨을 보여주었다. 이러한 분석을 바탕으로 프레임 시간, 탐색 부하, 탐색 성능을 종합적으로 고려한 전 탐색 영역 균일한 성능을 갖는 항공기 탑재 능동 위상 배열 레이더의 효과적인 빔 운용 방안을 제시하였다.

• 한국전산구조공학회:학술대회논문집
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• 한국전산구조공학회 2003년도 봄 학술발표회 논문집
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• pp.127-133
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• 2003

In this study, a problem formulation and solution for design optimization of laminate composite cylindrical beam section is presented. The objective of this research is to determine the optimal dimension of the laminated composite cylindrical beam sections which has the equivalent flexural rigidities to those of the steel cylindrical beam sections. The analytical model is based on the laminate theory and accounts for the material coupling for arbitrary laminate stacking sequence configuration. The outer diameter and thickness of the beam are design variables. The solutions described are found using a global search algorithm, Genetic Algorithms (GA).

• Structural Engineering and Mechanics
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• 제54권4호
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• pp.665-691
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• 2015

This study aims at comparing the optimum design of two common types open web expanded beams: with hexagonal openings, also called castellated beams and beams with circular openings referred to as cellular beams. The minimum weights of both beams are taken as the objective functions while the design constraints are respectively implemented from The Steel Construction Institute Publication Numbers 5 and 100. The design methods adopted in these publications are consistent with BS5950 parts. The formulation of the design problem considering the limitations of the above mentioned turns out to be a discrete programming problem. Improved harmony search algorithm is suggested to compare the optimum design of mentioned web-expanded beams to analysis the performance of both beams. The design algorithms based on the technique select the optimum Universal Beam sections, dimensional properties of hexagonal and circular holes and total number of openings along the beam as design variables.