• Title/Summary/Keyword: Adaptive operators

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Comparison of Adaptive Operators in Genetic Algorithms (유전알고리즘에서 적응적 연산자들의 비교연구)

  • Yun, Young-Su;Seo, Seoun-Lock
    • Journal of Intelligence and Information Systems
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    • v.8 no.2
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    • pp.189-203
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    • 2002
  • In this paper we compare the performances of adaptive operators in genetic algorithm. For the adaptive operators, the crossover and mutation operators of genetic algorithm are considered. One fuzzy logic controller is developed in this paper and two heuristics is presented from conventional works for constructing the operators. The fuzzy logic controller and two conventional heuristics adaptively regulate the rates of the operators during genetic search process. All the algorithms are tested and analyzed in numerical examples. Finally, the best algorithm is recommended.

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A New Approach to Adaptive HFC-based GAs: Comparative Study on Crossover Genetic Operator (적응 HFC 기반 유전자알고리즘의 새로운 접근: 교배 유전자 연산자의 비교연구)

  • Kim, Gil-Sung;Choi, Jeoung-Nae;Oh, Sung-Kwun
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.57 no.9
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    • pp.1636-1641
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    • 2008
  • In this study, we introduce a new approach to Parallel Genetic Algorithms (PGA) which combines AHFCGA with crossover operator. As to crossover operators, we use three types of the crossover operators such as modified simple crossover(MSX), arithmetic crossover(AX), and Unimodal Normal Distribution Crossover(UNDX) for real coding. The AHFC model is given as an extended and adaptive version of HFC for parameter optimization. The migration topology of AHFC is composed of sub-populations(demes), the admission threshold levels, and admission buffer for the deme of each threshold level through succesive evolution process. In particular, UNDX is mean-centric crossover operator using multiple parents, and generates offsprings obeying a normal distribution around the center of parents. By using test functions having multimodality and/or epistasis, which are commonly used in the study of function parameter optimization, Experimental results show that AHFCGA can produce more preferable output performance result when compared to HFCGA and RCGA.

THE CONSTRAINED ITERATIVE IMAGE RESTORATION ALGORITHM USING NEW REGULARIZATION OPERATORS

  • Lee, Sang-Hwa;Lee, Choong-Woong
    • Proceedings of the Korean Society of Broadcast Engineers Conference
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    • 1997.06a
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    • pp.107-112
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    • 1997
  • This paper proposes the regularized constrained iterative image restoration algorithms which apply new space-adaptive methods to degraded image signals, and analyzes the convergence condition of the proposed algorithm. First, we introduce space-adaptive regularization operators which change according to edge characteristics of local images in order to effectively prevent the restored edges and boundaries from reblurring. And, pseudo projection operator is used to reduce the ringing artifact which results from extensive amplification of noise components in the restoration process. The analysed algorithm is stable convergent to the fixed point. According to the experimental results for various signal-to-noise ratios(SNR) and blur models, the proposed algorithms other methods and is robust to noise effects and edge reblurring by regularization especially.

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Aircraft delivery vehicle with fuzzy time window for improving search algorithm

  • C.C. Hung;T. Nguyen;C.Y. Hsieh
    • Advances in aircraft and spacecraft science
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    • v.10 no.5
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    • pp.393-418
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    • 2023
  • Drones are increasingly used in logistics delivery due to their low cost, high-speed and straight-line flight. Considering the small cargo capacity, limited endurance and other factors, this paper optimized the pickup and delivery vehicle routing problem with time windows in the mode of "truck+drone". A mixed integer programming model with the objective of minimizing transportation cost was proposed and an improved adaptive large neighborhood search algorithm is designed to solve the problem. In this algorithm, the performance of the algorithm is improved by designing various efficient destroy operators and repair operators based on the characteristics of the model and introducing a simulated annealing strategy to avoid falling into local optimum solutions. The effectiveness of the model and the algorithm is verified through the numerical experiments, and the impact of the "truck+drone" on the route cost is analyzed, the result of this study provides a decision basis for the route planning of "truck+drone" mode delivery.

Evaluation of Various Tone Mapping Operators for Backward Compatible JPEG Image Coding

  • Choi, Seungcheol;Kwon, Oh-Jin;Jang, Dukhyun;Choi, Seokrim
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.9 no.9
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    • pp.3672-3684
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    • 2015
  • Recently, the standardization of backward compatible JPEG image coding for high dynamic range (HDR) image has been undertaken to establish an international standard called "JPEG XT." The JPEG XT consists of two layers: the base layer and the residual layer. The base layer contains tone mapped low dynamic range (LDR) image data and the residual layer contains the error signal used to reconstruct the HDR image. This paper gives the result of a study to evaluate the overall performance of tone mapping operators (TMOs) for this standard. The evaluation is performed using five HDR image datasets and six TMOs for profiles A, B, and C of the proposed JPEG XT standard. The Tone Mapped image Quality Index (TMQI) and no reference image quality assessment (NR IQA) are used for measuring the LDR image quality. The peak signal to noise ratio (PSNR) is used to evaluate the overall compression performance of JPEG XT profiles A, B, and C. In TMQI and NR IQA measurements, TMOs using display adaptive tone mapping and adaptive logarithmic mapping each gave good results. A TMO using adaptive logarithmic mapping gave good PSNRs.

An Adaptive Genetic Algorithm Based Optimal Feeder Routing for Distribution System Planning (적응 유전알고리즘을 이용한 배전계통 계획의 급전선 최적경로 선정)

  • Kim, Byung-Seop;Kim, Min-Soo;Shin, Joong-rin
    • The Transactions of the Korean Institute of Electrical Engineers A
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    • v.50 no.2
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    • pp.58-66
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    • 2001
  • This paper presents an application of a newly designed Adaptive Genetic Algorithm (AGA) to solve the Optimal Feeder Routing (OFR) problem for distribution system planning. The main objective of the OFR problem usually is to minimize the total cost that is the sum of investment costs and system operation costs. We propose a properly designed AGA, in this paper, which can handle the horizon-year expansion planning problem of power distribution network in which the location of substation candidates, the location and amount of forecasted demands are given. In the proposed AGA, we applied adaptive operators using specially designed adaptive probabilities. we also a Simplified Load Flow (SLF) technique for radial networks to improve a searching efficiency of AGA. The proposed algorithm has been evaluated with the practical 32, 69 bus test system to show favorable performance. It is also shown that the proposed method for the OFR can also be used for the network reconfiguration problem in distribution system.

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Optimal Routing for Distribution System Planning using New Adaptive GA (새로운 적응 유전 알고리즘을 이용한 배전계통계획의 최적경로탐색)

  • Kim, Min-Soo;Kim, Byung-Seop;Lee, Tae-Hyung;Shin, Joong-Rin
    • Proceedings of the KIEE Conference
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    • 2000.07a
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    • pp.137-141
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    • 2000
  • This paper presents an application of a new Adaptive Genetic Algorithms(AGA) to solve the Optimal Routing problem(ORP) for distribution system planning. In general, since the ORP is modeled as a mixed integer problem with some various mathematical constraints, it is hard to solve the problem. In this paper, we proposed a new adaptive strategy in GA to overcome the premature convergence and improve the convergence efficiency. And for these purposes, we proposed a fitness function suited for the ORP. In the proposed AGA, we used specially designed adaptive probabilities for genetic operators to consider the characteristics of distribution systems that are operated under radial configuration. The proposed algorithm has been tested in sample networks and the results are presented.

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Development of Adaptive Ground Control System for Multi-UAV Operation and Operator Overload Analysis (복수 무인기 운용을 위한 적응형 지상체 개발 및 운용자 과부하 분석)

  • Oh, Jangjin;Choi, Seong-Hwan;Lim, Hyung-Jin;Kim, Seungkeun;Yang, Ji Hyun;Kim, Byoung Soo
    • Journal of Advanced Navigation Technology
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    • v.21 no.6
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    • pp.529-536
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    • 2017
  • The general ground control system has control and information display functions for the operation of a single unmanned aerial vehicle. Recently, the function of the single ground control system extends to the operation of multiple UAVs. As a result, operators have been exposed to more diverse tasks and are subject to task overload due to various factors during their mission. This study proposes an adaptive ground control system that reflects the operator's condition through the task overload measurement of multiple UAV operators. For this, the ground control software is developed to control multiple UAVs at the same time, and the simulator with six degree-of-freedom aircraft dynamics is constructed for realistic human-machine-interface experiments by the operators.

An Adaptive Clustering Algorithm Based on Genetic Algorithm (유전자 알고리즘 기반 적응 군집화 알고리즘)

  • Park Namhyun;Ahn Chang Wook;Ramakrishna R.S.
    • Proceedings of the Korea Information Processing Society Conference
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    • 2004.11a
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    • pp.459-462
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    • 2004
  • This paper proposes a genetically inspired adaptive clustering algorithm. The algorithm automatically discovers the actual number of clusters and efficiently performs clustering without unduly compromising cluster purity. Chromosome encoding that ensures the correct number of clusters and cluster purity is discussed. The required fitness function is desisted on the basis of modified similarity criteria and genetic operators. These are incorporated into the proposed adaptive clustering algorithm. Experimental results show the efficiency of the clustering algorithm on synthetic data sets and real world data sets.

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Adaptive Directional Filtering Techniques for Image Sequences (동영상을 위한 적응 방향성 필터링 기술)

  • 고성제
    • The Journal of Korean Institute of Communications and Information Sciences
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    • v.18 no.7
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    • pp.922-934
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    • 1993
  • In this paper, statistical properties of the spatiotemporal center weighted median(CWM) filter for image sequences are investigated. It is statistically shown that the CWM filter preserves image structures under motion at the expense of noise suppression. To improve the CWM filter, a filter which can be effectively used in image sequence processing, the adaptive directional center weighted median filter (ADCWM), is proposed. This filter utilizes a multistage filtering structure based on adaptive symmetric order statistic(ASOS) operators which produce a pall of order statistics symmetric about the median. The ASOS's are selected by using adaptive parameters adjusted by local image statistics. It is shown experimentally that the proposed filter can preserve image structures while attenuating noise without the use of motion estimation.

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