• Title/Summary/Keyword: hybrid genetic algorithm

Search Result 416, Processing Time 0.029 seconds

A Decision Tree Induction using Genetic Programming with Sequentially Selected Features (순차적으로 선택된 특성과 유전 프로그래밍을 이용한 결정나무)

  • Kim Hyo-Jung;Park Chong-Sun
    • Korean Management Science Review
    • /
    • v.23 no.1
    • /
    • pp.63-74
    • /
    • 2006
  • Decision tree induction algorithm is one of the most widely used methods in classification problems. However, they could be trapped into a local minimum and have no reasonable means to escape from it if tree algorithm uses top-down search algorithm. Further, if irrelevant or redundant features are included in the data set, tree algorithms produces trees that are less accurate than those from the data set with only relevant features. We propose a hybrid algorithm to generate decision tree that uses genetic programming with sequentially selected features. Correlation-based Feature Selection (CFS) method is adopted to find relevant features which are fed to genetic programming sequentially to find optimal trees at each iteration. The new proposed algorithm produce simpler and more understandable decision trees as compared with other decision trees and it is also effective in producing similar or better trees with relatively smaller set of features in the view of cross-validation accuracy.

Performance Comparison of Discrete Particle Swarm Optimizations in Sequencing Problems (순서화 문제에서 01산적 Particle Swarm Optimization들의 성능 비교)

  • Yim, D.S.
    • Journal of Korean Society of Industrial and Systems Engineering
    • /
    • v.33 no.4
    • /
    • pp.58-68
    • /
    • 2010
  • Particle Swarm Optimization (PSO) which has been well known to solve continuous problems can be applied to discrete combinatorial problems. Several DPSO (Discrete Particle Swarm Optimization) algorithms have been proposed to solve discrete problems such as traveling salesman, vehicle routing, and flow shop scheduling problems. They are different in representation of position and velocity vectors, operation mechanisms for updating vectors. In this paper, the performance of 5 DPSOs is analyzed by applying to traditional Traveling Salesman Problems. The experiment shows that DPSOs are comparable or superior to a genetic algorithm (GA). Also, hybrid PSO combined with local optimization (i.e., 2-OPT) provides much improved solutions. Since DPSO requires more computation time compared with GA, however, the performance of hybrid DPSO is not better than hybrid GA.

Hybrid Approach When Multiple Objectives Exist

  • Kim, Young-Il;Lim, Yong-Bin
    • Communications for Statistical Applications and Methods
    • /
    • v.14 no.3
    • /
    • pp.531-540
    • /
    • 2007
  • When multiple objectives exist, there are three approaches exist. These are maximin design, compound design, and constrained design. Still, each of three design criteria has its own strength and weakness. In this paper Hybrid approach is suggested when multiple design objectives exist, which is a combination of maximin and constrained design. Sometimes experimenter has several objectives, but he/she has only one or two primary objectives, others less important. A new approach should be useful under this condition. The genetic algorithm is used for few examples. It has been proven to be a very useful technique for this complex situation. Conclusion follows.

Genetic Algorithm and Goal Programming Technique for Simultaneous Optimal Design of Structural Control System (구조-제어시스템의 동시최적설계를 위한 유전자알고리즘 및 Goal Programming 기법)

  • 옥승용;박관순;고현무
    • Proceedings of the Earthquake Engineering Society of Korea Conference
    • /
    • 2003.09a
    • /
    • pp.497-504
    • /
    • 2003
  • An optimal design method for hybrid structural control system of building structures subject to earthquake excitation is presented in this paper. Designing a hybrid structural control system nay be defined as a process that optimizes the capacities and configuration of passive and active control systems as well as structural members. The optimal design proceeds by formulating the optimization problem via a multi-stage goal programming technique and, then, by finding reasonable solution to the optimization problem by means of a goal-updating genetic algorithm. The process of the integrated optimization design is illustrated by a numerical simulation of a nine-story building structure subject to earthquake excitation. The effectiveness of the proposed method is demonstrated by comparing the optimally designed results with those of a hybrid structural control system where structural members, passive and active control systems are uniformly distributed.

  • PDF

A Neuro-Fuzzy Approach to Integration and Control of Industrial Processes:Part I

  • Kim, Sung-Shin
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.8 no.6
    • /
    • pp.58-69
    • /
    • 1998
  • This paper introduces a novel neuro-fuzzy system based on the polynomial fuzzy neural network(PFNN) architecture. The PFNN consists of a set of if-then rules with appropriate membership functions whose parameters are optimized via a hybrid genetic algorithm. A polynomial neural network is employed in the defuzzification scheme to improve output performance and to select appropriate rules. A performance criterion for model selection, based on the Group Method of DAta Handling is defined to overcome the overfitting problem in the modeling procedure. The hybrid genetic optimization method, which combines a genetic algorithm and the Simplex method, is developed to increase performance even if the length of a chromosome is reduced. A novel coding scheme is presented to describe fuzzy systems for a dynamic search rang in th GA. For a performance assessment of the PFNN inference system, three well-known problems are used for comparison with other methods. The results of these comparisons show that the PFNN inference system outperforms the other methods while it exhibits exceptional robustness characteristics.

  • PDF

A Hybrid Genetic Algorithm for Vehicle Routing Problem which Considers Traffic Situations and Stochastic Demands (교통상황과 확률적 수요를 고려한 차량경로문제의 Hybrid 유전자 알고리즘)

  • Kim, Gi-Tae;Jeon, Geon-Uk
    • Journal of Korean Society of Transportation
    • /
    • v.28 no.5
    • /
    • pp.107-116
    • /
    • 2010
  • The vehicle travel time between locations in a downtown is greatly influenced by both complex road conditions and traffic situation that changes real time according to various external variables. The customer's demands also stochastically change by time period. Most vehicle routing problems suggest a vehicle route considering travel distance, average vehicle speed, and deterministic demand; however, they do not consider the dynamic external environment, including items such as traffic conditions and stochastic demand. A realistic vehicle routing problem which considers traffic (smooth, delaying, and stagnating) and stochastic demands is suggested in this study. A mathematical programming model and hybrid genetic algorithm are suggested to minimize the total travel time. By comparing the results considering traffic and stochastic demands, the suggested algorithm gives a better solution than existing algorithms.

Using Bayesian tree-based model integrated with genetic algorithm for streamflow forecasting in an urban basin

  • Nguyen, Duc Hai;Bae, Deg-Hyo
    • Proceedings of the Korea Water Resources Association Conference
    • /
    • 2021.06a
    • /
    • pp.140-140
    • /
    • 2021
  • Urban flood management is a crucial and challenging task, particularly in developed cities. Therefore, accurate prediction of urban flooding under heavy precipitation is critically important to address such a challenge. In recent years, machine learning techniques have received considerable attention for their strong learning ability and suitability for modeling complex and nonlinear hydrological processes. Moreover, a survey of the published literature finds that hybrid computational intelligent methods using nature-inspired algorithms have been increasingly employed to predict or simulate the streamflow with high reliability. The present study is aimed to propose a novel approach, an ensemble tree, Bayesian Additive Regression Trees (BART) model incorporating a nature-inspired algorithm to predict hourly multi-step ahead streamflow. For this reason, a hybrid intelligent model was developed, namely GA-BART, containing BART model integrating with Genetic algorithm (GA). The Jungrang urban basin located in Seoul, South Korea, was selected as a case study for the purpose. A database was established based on 39 heavy rainfall events during 2003 and 2020 that collected from the rain gauges and monitoring stations system in the basin. For the goal of this study, the different step ahead models will be developed based in the methods, including 1-hour, 2-hour, 3-hour, 4-hour, 5-hour, and 6-hour step ahead streamflow predictions. In addition, the comparison of the hybrid BART model with a baseline model such as super vector regression models is examined in this study. It is expected that the hybrid BART model has a robust performance and can be an optional choice in streamflow forecasting for urban basins.

  • PDF

A Hybrid Genetic Algorithm Using Epistasis Information for Sequential Ordering Problems (서열순서화문제를 위한 상위정보를 이용하는 혼합형 유전 알고리즘)

  • Seo Dong-Il;Moon Byung-Ro
    • Journal of the Korean Institute of Intelligent Systems
    • /
    • v.15 no.6
    • /
    • pp.661-667
    • /
    • 2005
  • In this paper, we propose a new hybrid genetic algorithm for sequential ordering problem (SOP). In the proposed genetic algorithm, the Voronoi quantized crossover (VQX) is used as a crossover operator and the path-preserving 3-Opt is used as a local search heuristic. VQX is a crossotver operator that uses the epistasis information of given problem instance. Since it is a crossover proposed originally for the traveling salesman problem (TSP), its application to SOP requires considerable modification. In this study, we appropriately modify VQX for SOP, and develop three algorithms, required in the modified VQX, named Feasible solution Generation Algorithm, Precedence Cycle Decomposition Algorithm, and Genic Distance Assignment Method. The results of the tests on SOP instances obtained from TSPLIB and ZIB-MP-Testdata show that the proposed genetic algorithm outperforms other genetic algorithms in stability and solution quality.

A hybrid genetic algorithm for the optimal transporter management plan in a shipyard

  • Jun-Ho Park;Yung-Keun Kwon
    • Journal of the Korea Society of Computer and Information
    • /
    • v.28 no.12
    • /
    • pp.49-56
    • /
    • 2023
  • In this study, we propose a genetic algorithm (GA) to optimize the allocation and operation order of transporters. The solution in the GA is represented by a set of lists each of which the operation order of the corresponding transporter. In addition, it was implemented in the form of a hybrid genetic algorithm combining effective local search operations for performance improvement. The local search reduces the number of operating transporters by moving blocks from a transporter with a low workload into that with a high workload. To evaluate the effectiveness of the proposed algorithm, it was compared with Multi-Start and a pure genetic algorithm through a simulation environment similar in scale to an actual shipyard. For the largest problem, compared to them, the number of transporters was reduced by 40% and 34%, and the total task time was reduced by 27% and 17%, respectively.

FE Model Updating on the Grillage Model for Plate Girder Bridge Using the Hybrid Genetic Algorithm and the Multi-objective Function (하이브리드 유전자 알고리즘과 다중목적함수를 적용한 플레이트 거더교의 격자모델에 대한 유한요소 모델개선)

  • Jung, Dae-Sung;Kim, Chul-Young
    • Journal of the Earthquake Engineering Society of Korea
    • /
    • v.12 no.6
    • /
    • pp.13-23
    • /
    • 2008
  • In this study, a finite element (FE) model updating method based on the hybrid genetic algorithm (HGA) is proposed to improve the grillage FE model for plate girder bridges. HGA consists of a genetic algorithm (GA) and direct search method (DS) based on a modification of Nelder & Mead's simplex optimization method (NMS). Fitness functions based on natural frequencies, mode shapes, and static deflections making use of the measurements and analytical results are also presented to apply in the proposed method. In addition, a multi-objective function has been formulated as a linear combination of fitness functions in order to simultaneously improve both stiffness and mass. The applicability of the proposed method to girder bridge structures has been verified through a numerical example on a two-span continuous grillage FE model, as well as through an experimental test on a simply supported plate girder skew bridge. In addition, the effect of measuring error is considered as random noise, and its effect is investigated by numerical simulation. Through numerical and experimental verification, it has been proven that the proposed method is feasible and effective for FE model updating on plate girder bridges.