• Smart Structures and Systems
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• 제17권2호
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• pp.347-361
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• 2016

A two-stage method for damage detection in truss systems is proposed. In the first stage, a modal residual vector based indicator (MRVBI) is introduced to locate the potentially damaged elements and reduce the damage variables of a truss structure. Then, in the second stage, a differential evolution (DE) based optimization method is implemented to find the actual site and extent of damage in the structure. In order to assess the efficiency of the proposed damage detection method, two numerical examples including a 2D-truss and 3D-truss are considered. Simulation results reveal the high performance of the method for accurately identifying the damage location and severity of trusses with considering the measurement noise.

• 한국시뮬레이션학회논문지
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• 제14권3호
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• pp.43-54
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• 2005

For the effective design of automated distribution center composed of Automated Storage/Retrieval System, Automated Guided Vehicle System, and Conveyor System, we proposed an analysis method to determining. design and control parameters with multiple performance objectives using Compromise Programming, which can resolve the dilemma of conflicting objectives. The Evolution Strategy generates the optimal solutions for each objectives. The Analytic Hierarchy Process selects the best solution among the alternatives generated from Evolution Strategy. The Regression Analysis formulates the objective functions for each objectives. By reducing deviations between goal values and target values generated from Analytic Hierarchy Process, Compromise Programming determines design and control parameters by compromising the multiple objectives formulated using Regression Analysis. When the parameters of system are changed, this proposed analysis method has a benefit of reducing costs and time without repeating whole simulation run.

• 지능정보연구
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• 제1권2호
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• pp.73-83
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• 1995

본 논문 에서는 진화 알고리즘을 이용하여 퍼지 규칙 베이스의 최적 규칙들을 자동으로 생성하는 방법을 제안한다. 진화 알고리즘에 의한 퍼지 논리 시스템의 최적 규칙은 전문가의 사전 경험이나 지식이 없이도 자동 설계가 가능하고 이들 규칙을 이용하여 지능 제어를 할 수 있다. 본 논문에서 사용한 접근 방법은 퍼지 규칙 소속함수의 자동 조정으로 규칙을 생성하고, 최적의 제어 규칙 탐색은 퍼지 논리 시스템의 성능 기준으로 정의한 적합도 값을 기반으로 탐색한다. 제안한 방법의 유용성을 보이기 위해 비선형 시스템에서 컴퓨터 모의실험을 행하였다.

• Journal of information and communication convergence engineering
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• 제17권4호
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• pp.261-266
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• 2019

Differential evolution (DE) is an uncomplicated and serviceable developmental algorithm. Nevertheless, its execution depends on strategies and regulating structures. The combination of several strategies between subpopulations helps to stabilize the probing on DE. In this paper, we propose a unique k-mean soft island model DE(KSDE) algorithm which maintains population diversity through soft island model (SIM). A combination of various approaches, called KSDE, intended for migrating the subpopulation information through SIM is developed in this study. First, the population is divided into k subpopulations using the k-means clustering algorithm. Second, the mutation pattern is singled randomly from a strategy pool. Third, the subpopulation information is migrated using SIM. The performance of KSDE was analyzed using 13 benchmark indices and compared with those of high-technology DE variants. The results demonstrate the efficiency and suitability of the KSDE system, and confirm that KSDE is a cost-effective algorithm compared with four other DE algorithms.

• 대한전기학회:학술대회논문집
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• 대한전기학회 1999년도 하계학술대회 논문집 G
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• pp.2944-2946
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• 1999

In this paper, digital circuit evolution is proposed as an intrinsic evolvable system. Evolutionary hardware is a reconfigurable one which adapt itself to the environment and evolve its structure to realize desired performance. By using special FPGA and genetic algorithm, we have made a prototype of intrinsic hardware evolution system. As an example for digital circuit evolution, full adder realization is performed. As the result of this, a very complex structure of digital circuit performing full adder was created. Analysis made on the hardware revealed that some undetermined circuits were developed.

• 인터넷정보학회논문지
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• 제22권2호
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• pp.19-27
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• 2021

Fireworks Algorithm (FWA) is a new heuristic swarm intelligent algorithm inspired by the natural phenomenon of the fireworks explosion. Though it is an effective algorithm for solving optimization problems, FWA has a slow convergence rate and less information sharing between individuals. In this paper, we improve the FWA. Firstly, explosion operator and explosion amplitude are analyzed in detail. The coefficient of explosion amplitude and explosion operator change dynamically with iteration to balance the exploitation and exploration. The convergence performance of FWA is improved. Secondly, differential evolution and commensal learning (CDE) significantly increase the information sharing between individuals, and the diversity of fireworks is enhanced. Comprehensive experiment and comparison with CDE, FWA, and VACUFWA for the 13 benchmark functions show that the improved algorithm was highly competitive.

• 인터넷정보학회논문지
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• 제22권1호
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• pp.1-11
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• 2021

Estimation of distribution algorithm (EDA) is a popular stochastic metaheuristic algorithm. EDA has been widely utilized in various optimization problems. However, it has been shown that the diversity of the population gradually decreases during the iterations, which makes EDA easily lead to premature convergence. This article introduces a hybrid estimation of distribution algorithm (EDA) with differential evolution (DE) based on self-adaptive strategy, namely HEDADE-SA. Firstly, an alternative probability model is used in sampling to improve population diversity. Secondly, the proposed algorithm is combined with DE, and a self-adaptive strategy is adopted to improve the convergence speed of the algorithm. Finally, twenty-five benchmark problems are conducted to verify the performance of HEDADE-SA. Experimental results indicate that HEDADE-SA is a feasible and effective algorithm.

• International Journal of Aerospace System Engineering
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• 제7권2호
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• pp.6-12
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• 2020

The precise prediction of future position of satellite depends on the accurate determination of orbit, which is also helpful in performing orbit maneuvers and trajectory correction maneuvers. For estimating the orbit of satellite many methods are being used. Some of the conventional methods are based on (i) Differential Correction (DC) (ii) Extended Kalman Filter (EKF). In this paper, Differential Evolution (DE) is used to determine the orbit. Orbit Determination using DC and EKF requires some initial guess of the state vector to initiate the algorithm, whereas DE does not require an initial guess since a wide range of bounds for the design unknown variables (orbital elements) is sufficient. This technique is uniformly valid for all orbits viz. circular, elliptic or hyperbolic. Simulated observations have been used to demonstrate the performance of the method. The observations are generated by including random noise. The simulation model that generates the observations includes the perturbation due to non-spherical earth up to second zonal harmonic term.

• Journal of Electrochemical Science and Technology
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• 제14권3호
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• pp.243-251
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• 2023

Developing oxygen evolution reaction (OER) electrocatalysts is essential to accomplish viable CO₂ and water electrolysis. Herein, we report the fabrication and OER performance of Ni-foam (NF)-immobilized Ni₆ nanoclusters (NCs) (Ni₆/NF) prepared by a dip-coating process. The Ni₆/NF electrode exhibited a high current density of 500 mA/cm² for the OER at an overpotential as low as 0.39 V. Ni₆/NF exhibited high durability in an alkaline solution without corrosion. Electrokinetic studies revealed that OER can be easily initiated on Ni6 NC with fast electron-transfer rates. Finally, we demonstrated stable CO₂-to-CO electroreduction using an NC-based zero-gap CO₂ electrolyzer operated at a current density of 100 mA/cm² and a full-cell potential of 2.0 V for 12 h.

• 한국정보통신학회:학술대회논문집
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• 한국정보통신학회 2018년도 추계학술대회
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• pp.568-570
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• 2018

최근 이동통신기술의 급속한 발달과 보급으로 LTE(Long Term Evolution) 기술은 스마트폰 서비스를 넘어 산업통신이나 긴급통신을 비롯하여 다양한 분야로 확대되고 있다. 본 연구에서는 LTE 기술의 응용 분야로서 LTE-R을 기반으로 하는 철도통신의 서비스 분야 가운데 하나인 음성서비스의 전송성능을 분석하고자 한다. 본 연구에서는 LTE-R 네트워크의 응용서비스 관점에서 성능을 분석하여 응용서비스가 사용자 만족도에 미치는 영향을 살펴본다. 분석방법으로는 NS(Network Simulator)-3에 기반한 컴퓨터 시뮬레이션을 사용하며 분석대상 트래픽으로는 VoIP(Voice over Internet Protocol) 규격 음성트래픽을 사용한다. 본 연구의 결과는 LTE-R 네트워크 구축뿐 아니라 LTE-R 네트워크를 대상으로 하는 응용서비스 개발에 활용이 가능하다. 다음은 요약문 입니다.