• Title/Summary/Keyword: Improved genetic algorithm

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Self-optimizing feature selection algorithm for enhancing campaign effectiveness (캠페인 효과 제고를 위한 자기 최적화 변수 선택 알고리즘)

  • Seo, Jeoung-soo;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.26 no.4
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    • pp.173-198
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    • 2020
  • For a long time, many studies have been conducted on predicting the success of campaigns for customers in academia, and prediction models applying various techniques are still being studied. Recently, as campaign channels have been expanded in various ways due to the rapid revitalization of online, various types of campaigns are being carried out by companies at a level that cannot be compared to the past. However, customers tend to perceive it as spam as the fatigue of campaigns due to duplicate exposure increases. Also, from a corporate standpoint, there is a problem that the effectiveness of the campaign itself is decreasing, such as increasing the cost of investing in the campaign, which leads to the low actual campaign success rate. Accordingly, various studies are ongoing to improve the effectiveness of the campaign in practice. This campaign system has the ultimate purpose to increase the success rate of various campaigns by collecting and analyzing various data related to customers and using them for campaigns. In particular, recent attempts to make various predictions related to the response of campaigns using machine learning have been made. It is very important to select appropriate features due to the various features of campaign data. If all of the input data are used in the process of classifying a large amount of data, it takes a lot of learning time as the classification class expands, so the minimum input data set must be extracted and used from the entire data. In addition, when a trained model is generated by using too many features, prediction accuracy may be degraded due to overfitting or correlation between features. Therefore, in order to improve accuracy, a feature selection technique that removes features close to noise should be applied, and feature selection is a necessary process in order to analyze a high-dimensional data set. Among the greedy algorithms, SFS (Sequential Forward Selection), SBS (Sequential Backward Selection), SFFS (Sequential Floating Forward Selection), etc. are widely used as traditional feature selection techniques. It is also true that if there are many risks and many features, there is a limitation in that the performance for classification prediction is poor and it takes a lot of learning time. Therefore, in this study, we propose an improved feature selection algorithm to enhance the effectiveness of the existing campaign. The purpose of this study is to improve the existing SFFS sequential method in the process of searching for feature subsets that are the basis for improving machine learning model performance using statistical characteristics of the data to be processed in the campaign system. Through this, features that have a lot of influence on performance are first derived, features that have a negative effect are removed, and then the sequential method is applied to increase the efficiency for search performance and to apply an improved algorithm to enable generalized prediction. Through this, it was confirmed that the proposed model showed better search and prediction performance than the traditional greed algorithm. Compared with the original data set, greed algorithm, genetic algorithm (GA), and recursive feature elimination (RFE), the campaign success prediction was higher. In addition, when performing campaign success prediction, the improved feature selection algorithm was found to be helpful in analyzing and interpreting the prediction results by providing the importance of the derived features. This is important features such as age, customer rating, and sales, which were previously known statistically. Unlike the previous campaign planners, features such as the combined product name, average 3-month data consumption rate, and the last 3-month wireless data usage were unexpectedly selected as important features for the campaign response, which they rarely used to select campaign targets. It was confirmed that base attributes can also be very important features depending on the type of campaign. Through this, it is possible to analyze and understand the important characteristics of each campaign type.

Constrained Relay Node Deployment using an improved multi-objective Artificial Bee Colony in Wireless Sensor Networks

  • Yu, Wenjie;Li, Xunbo;Li, Xiang;Zeng, Zhi
    • KSII Transactions on Internet and Information Systems (TIIS)
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    • v.11 no.6
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    • pp.2889-2909
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    • 2017
  • Wireless sensor networks (WSNs) have attracted lots of attention in recent years due to their potential for various applications. In this paper, we seek how to efficiently deploy relay nodes into traditional static WSNs with constrained locations, aiming to satisfy specific requirements of the industry, such as average energy consumption and average network reliability. This constrained relay node deployment problem (CRNDP) is known as NP-hard optimization problem in the literature. We consider addressing this multi-objective (MO) optimization problem with an improved Artificial Bee Colony (ABC) algorithm with a linear local search (MOABCLLS), which is an extension of an improved ABC and applies two strategies of MO optimization. In order to verify the effectiveness of the MOABCLLS, two versions of MO ABC, two additional standard genetic algorithms, NSGA-II and SPEA2, and two different MO trajectory algorithms are included for comparison. We employ these metaheuristics on a test data set obtained from the literature. For an in-depth analysis of the behavior of the MOABCLLS compared to traditional methodologies, a statistical procedure is utilized to analyze the results. After studying the results, it is concluded that constrained relay node deployment using the MOABCLLS outperforms the performance of the other algorithms, based on two MO quality metrics: hypervolume and coverage of two sets.

Universal and Can be Applied Wireless Channel Assignment Algorithm (범용 적용이 가능한 무선채널할당알고리즘)

  • Heo, Seo-Jung;Son, Dong-Cheul;Kim, Chang-Suk
    • Journal of Digital Convergence
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    • v.10 no.9
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    • pp.375-381
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    • 2012
  • If a mobile station requests a channel allocation in its mobile networks, the switching center assigns a channel to a mobile station that belongs to each base station. There are three kinds of channel allocation schemes; a fixed channel allocation, a dynamic channel allocation and a hybrid combination of these two forms. In assigning a good frequency, it is our intention to provide quality service to our customers as well as to use resources efficiently. This paper proposes methods of assigning frequencies that minimize interference between channels and that also minimize the amount of searching time involved. In this paper, we propose an algorithm to per specific equipment, regardless of the number of channels that can be used as a general-purpose system, such as base stations, control stations, central office model is proposed, the existing operators manner similar to the fixed channel allocation based statistics and assigned when the conventional method and the improved method is proposed. Different ways and compared via simulations to verify the effectiveness of the proposed approach.

Identification of prognosis-specific network and prediction for estrogen receptor-negative breast cancer using microarray data and PPI data (마이크로어레이 데이터와 PPI 데이터를 이용한 에스트로겐 수용체 음성 유방암 환자의 예후 특이 네트워크 식별 및 예후 예측)

  • Hwang, Youhyeon;Oh, Min;Yoon, Youngmi
    • Journal of the Korea Society of Computer and Information
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    • v.20 no.2
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    • pp.137-147
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    • 2015
  • This study proposes an algorithm for predicting breast cancer prognosis based on genetic network. We identify prognosis-specific network using gene expression data and PPI(protein-protein interaction) data. To acquire the network, we calculate Pearson's correlation coefficient(PCC) between genes in all PPI pairs using gene expression data. We develop a prediction model for breast cancer patients with estrogen-receptor-negative using the network as a classifier. We compare classification performance of our algorithm with existing algorithms on independent data and shows our algorithm is improved. In addition, we make an functionality analysis on the genes in the prognosis-specific network using GO(Gene Ontology) enrichment validation.

Redundancy Allocation in A Multi-Level Series System by Cuckoo Search (뻐꾸기 탐색 방법을 활용한 다계층 시스템의 중복 할당 최적화)

  • Chung, Il-Han
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.18 no.4
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    • pp.334-340
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    • 2017
  • Reliability is considered a particularly important design factor for systems that have critical results once a failure occurs in a system, such as trains, airplanes, and passenger ships. The reliability of the system can be improved in several ways, but in a system that requires considerable reliability, the redundancy of parts is efficient in improving the system reliability. In the case of duplicating parts to improve reliability, the kind of parts and the number of duplicating parts should be determined under the system reliability, part costs, and resources. This study examined the redundancy allocation of multi-level systems with serial structures. This paper describes the definition of a multi-system and how to optimize the kind of parts and number of duplications to maximize the system reliability. To optimize the redundancy, the cuckoo search algorithm was applied. The search procedure, the solution representation and the development of the neighborhood solution were proposed to optimize the redundancy allocation of a multi-level system. The results of numerical experiments were compared with the genetic algorithm and cuckoo search algorithm.

Optimization of Array Configuration in Time Reversal Processing (시역전 처리에서 센서 배열 최적화에 관한 연구)

  • Joo, Jae-Hoon;Kim, Jea-Soo;Ji, Yoon-Hee;Chung, Jae-Hak;Kim, Duk-Yung
    • The Journal of the Acoustical Society of Korea
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    • v.29 no.7
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    • pp.411-421
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    • 2010
  • A time-reversal mirror (TRM) is useful in diverse areas, such as reverberation ing, target echo enhancement and underwater communication. In underwater communication, the bit error rate has been improved significantly due to the increased signal-to-noise ratio by spatio-temporal focusing. This paper deals with two issues. First, the optimal number of array elements for a given environment was investigated based on the exploitation of spatial diversity. Second, an algorithm was developed to determine the optimal location of the given number of array elements. The formulation is based on a genetic algorithm maximizing the contrast between the foci and area of interest as an objective function. In addition, the developed algorithm was applied to the matched field processing with ocean experimental data for verification. The sea-going data and simulation showed almost 3 dB improvement in the output power at the foci when the array elements were optimally distributed.

Generic optimization, energy analysis, and seismic response study for MSCSS with rubber bearings

  • Fan, Buqiao;Zhang, Xun'an;Abdulhadi, Mustapha;Wang, Zhihao
    • Earthquakes and Structures
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    • v.19 no.5
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    • pp.347-359
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    • 2020
  • The Mega-Sub Controlled Structure System (MSCSS), an innovative vibration passive control system for building structures, is improved by adding lead rubber bearings (LRBs) on top of the substructure. For the new system, a genetic algorithm is used to optimize the dynamic parameters and distributions of dampers and LRBs. The program uses various seismic performance indicators as optimization objectives, and corresponding results are compared. It is found that the optimization procedure for maximizing the energy dissipation ratio yields the best solutions, and optimized models have consistent seismic performances under different earthquakes. Seismic performances of optimized MSCSS models with and without LRBs, as well as the traditional Mega-Sub Structure model, are evaluated and compared under El Centro wave, Taft wave and 20 other artificial waves. In both elastic and plastic analysis, the model with LRBs shows significantly smaller story drift and horizontal acceleration than those of the other two models, and fewer plastic hinges are developed during severe earthquakes. Energy analysis also shows that LRBs installed in proper locations increase the deformation and energy dissipation of dampers, thereby significantly reduce the kinetic, potential, and hysteretic energy in the structure. However, LRBs do not have to be mounted on all the additional columns. It is also demonstrated that LRBs at unfavorable locations can decrease the energy dissipation for dampers. After LRBs are installed, the optimal damping coefficient and the optimal damping exponent of dampers are reduced to produce the best damping effect.

A New Method of PAPR Reduction in OFDM Systems Using Modified GA-SPW (변형된 GA-SPW에 의한 OFDM의 새로운 PAPR 감소 기법)

  • Kim, Sung-Soo;Kim, Myoung-Je
    • The Journal of Korean Institute of Electromagnetic Engineering and Science
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    • v.17 no.11 s.114
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    • pp.1065-1072
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    • 2006
  • An OFDM(Orthogonal Frequency Division Multiplexing) system has the problem of the PAPR(Peak-to-Average Power Ratio) due to the overlapping phenomena of many sub-carriers. The previously proposed GA-SPW(Genetic Sub-block Phase Weighting) method not only improved the reduction of PAPR as the number of sub-blocks increases in an OFDM symbol but also decreased the number of calculations involved in the iterative phase searching yields to depend on the number of population and generation by using genetic algorithm not on the number of sub-blocks and phase elements. In this paper, we propose the modified GA-SPW method in order to improve the performance and to decrease the complexity. It is shown that the proposed modified GA-SPW method achieves the significant performance and the reduction of search complexity comparing to the ordinary technique, iterative flipping and previously proposed GA-SPW by the experimental results and analysis.

Gene-Gene Interaction Analysis for the Accelerated Failure Time Model Using a Unified Model-Based Multifactor Dimensionality Reduction Method

  • Lee, Seungyeoun;Son, Donghee;Yu, Wenbao;Park, Taesung
    • Genomics & Informatics
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    • v.14 no.4
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    • pp.166-172
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    • 2016
  • Although a large number of genetic variants have been identified to be associated with common diseases through genome-wide association studies, there still exits limitations in explaining the missing heritability. One approach to solving this missing heritability problem is to investigate gene-gene interactions, rather than a single-locus approach. For gene-gene interaction analysis, the multifactor dimensionality reduction (MDR) method has been widely applied, since the constructive induction algorithm of MDR efficiently reduces high-order dimensions into one dimension by classifying multi-level genotypes into high- and low-risk groups. The MDR method has been extended to various phenotypes and has been improved to provide a significance test for gene-gene interactions. In this paper, we propose a simple method, called accelerated failure time (AFT) UM-MDR, in which the idea of a unified model-based MDR is extended to the survival phenotype by incorporating AFT-MDR into the classification step. The proposed AFT UM-MDR method is compared with AFT-MDR through simulation studies, and a short discussion is given.

Optimal Design of Medical Bed Head Consol Considering the Strength Condition (의료용 베드 헤드 콘솔의 강도조건을 고려한 최적 설계)

  • Byon, Sung-Kwang;Choi, Ha-Young;Lee, Bong-Gu
    • Journal of the Korean Society of Manufacturing Process Engineers
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    • v.15 no.3
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    • pp.8-14
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    • 2016
  • Medical bed head consoles (BHC) are generally used to increase the efficiency of medical equipment and speed the medical treatment response time. The BHC design has been consistently improved including a movable shelf unit that is embedded to mount stably medical instruments on the lower part of the main console. The cost of a BHC can be reduced through design optimization to limit the overall weight. However, as the size of a head console might decrease due to design optimization, the BHC deflection could be increased. In this study, multi-objective optimal design was adopted to consider this BHC design problem. In order to reduce the cost of optimization planning, an approximate model was applied for the design optimization. In the context of approximate optimization, we used the response surface method and non-dominant sorting genetic algorithm developed from various fields. Multi-objective optimal solutions were also compared with a single objective optimal design.