• Title/Summary/Keyword: Hybrid $A^*$ algorithm

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Study on the Hybrid HRN Algorithm for Efficient Elevator Boarding Considering the Users' Waiting Time (사용자의 효율적인 엘리베이터 탑승 대기시간을 위한 Hybrid HRN Algorithm 연구)

  • Baek, Jin-Woo;Yeom, Gi-Hun;Chung, Sung-Wook
    • The Journal of Korea Institute of Information, Electronics, and Communication Technology
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    • v.15 no.1
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    • pp.45-55
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    • 2022
  • Currently, the Collective Control Algorithm is the most popular elevator algorithm. The Collective Control Algorithm allows the user to use the elevator when the direction of movement of the elevator and the direction of the user's destination are the same. However, the algorithm has a problem in that only one elevator responds to a user's call when the user's waiting time and using multiple elevators. To solve this problem, this paper proposes a new hybrid HRN algorithm based on the highest response ratio next (HRN) algorithm. In general, HRN Algorithm requires a user's boarding time and getting off time, but due to the nature of the elevator, it is difficult to predict the user's call in advance. Therefore, to overcome these limitations, this paper proposes Hybrid HRN Algorithm that considers the distance between the user's call location and the arrival location. This paper shows that Hybrid HRN Algorithm, proposed through experiments, has an average waiting time of 23.34 seconds, a standard deviation of 11.86, a total moving distance of 535.2m, a total operating time of 84sec, and a driving balance between the two elevators is 92m, which is superior to the previously suggested Collective Control, Zoning, and 3-Passage Algorithm.

Parameter Identification Using Hybrid Neural-Genetic Algorithm in Electro-Hydraulic Servo System (신경망-유전자 알고리즘을 이용한 전기${\cdot}$유압 서보시스템의 파라미터 식별)

  • 곽동훈;정봉호;이춘태;이진걸
    • Journal of the Korean Society for Precision Engineering
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    • v.19 no.11
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    • pp.192-199
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    • 2002
  • This paper demonstrates that hybrid neural-genetic multimodel parameter estimation algorithm can be applied to structured system Identification of electro-hydraulic servo system. This algorithm are consist of a recurrent incremental credit assignment (ICRA) neural network and a genetic algorithm. The ICRA neural network evaluates each member of a generation of model and genetic algorithm produces new generation of model. We manufactured electro-hydraulic servo system and the hybrid neural-genetic multimodel parameter estimation algorithm is applied to the task to find the parameter values(mass, damping coefficient, bulk modulus, spring coefficient) which minimize total square error.

Parameter Identification of an Electro-Hydraulic Servo System Using an Improved Hybrid Neural-Genetic Multimodel Algorithm (개선된 신경망-유전자 다중모델에 의한 전기.유압 서보시스템의 파라미터 식별)

  • 곽동훈;정봉호;이춘태;이진걸
    • Journal of the Korean Society for Precision Engineering
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    • v.20 no.5
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    • pp.196-203
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    • 2003
  • This paper demonstrates that an improved hybrid neural-genetic multimodel parameter estimation algorithm can be applied to the structured system identification of an electro-hydraulic servo system. This algorithm is consists of a recurrent incremental credit assignment (ICRA) neural network and a genetic algorithm, The ICRA neural network evaluates each member of a generation of model and the genetic algorithm produces new generation of model. We manufactured an electro-hydraulic servo system and the improved hybrid neural-genetic multimodel parameter estimation algorithm is applied to the task to find the parameter values, such as mass, damping coefficient, bulk modulus, spring coefficient and disturbance, which minimize total square error.

An Optimization Method Based on Hybrid Genetic Algorithm for Scramjet Forebody/Inlet Design

  • Zhou, Jianxing;Piao, Ying;Cao, Zhisong;Qi, Xingming;Zhu, Jianhong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2008.03a
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    • pp.469-475
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    • 2008
  • The design of a scramjet inlet is a process to search global optimization results among those factors influencing the geometry of scramjet in their ranges for some requirements. An optimization algorithm of hybrid genetic algorithm based on genetic algorithm and simplex algorithm was established for this purpose. With the sample provided by a uniform method, the compressive angles which also are wedge angles of the inlet were chosen as the inlet design variables, and the drag coefficient, total pressure recovery coefficient, pressure rising ratio and the combination of these three variables are designed specifically as different optimization objects. The contrasts of these four optimization results show that the hybrid genetic algorithm developed in this paper can capably implement the optimization process effectively for the inlet design and demonstrate some good adaptability.

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A Hybrid Learning Model to Detect Morphed Images

  • Kumari, Noble;Mohapatra, AK
    • International Journal of Computer Science & Network Security
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    • v.22 no.6
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    • pp.364-373
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    • 2022
  • Image morphing methods make seamless transition changes in the image and mask the meaningful information attached to it. This can be detected by traditional machine learning algorithms and new emerging deep learning algorithms. In this research work, scope of different Hybrid learning approaches having combination of Deep learning and Machine learning are being analyzed with the public dataset CASIA V1.0, CASIA V2.0 and DVMM to find the most efficient algorithm. The simulated results with CNN (Convolution Neural Network), Hybrid approach of CNN along with SVM (Support Vector Machine) and Hybrid approach of CNN along with Random Forest algorithm produced 96.92 %, 95.98 and 99.18 % accuracy respectively with the CASIA V2.0 dataset having 9555 images. The accuracy pattern of applied algorithms changes with CASIA V1.0 data and DVMM data having 1721 and 1845 set of images presenting minimal accuracy with Hybrid approach of CNN and Random Forest algorithm. It is confirmed that the choice of best algorithm to find image forgery depends on input data type. This paper presents the combination of best suited algorithm to detect image morphing with different input datasets.

A Study on a Hybrid Genetic Algorithm for the Analysis of Inverse Radiation (역복사 해석을 위한 혼합형 유전 알고리듬에 관한 연구)

  • Kim, Ki-Wan;Baek, Seung-Wook;Kim, Man-Young;Ryou, Hong-Sun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.27 no.10
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    • pp.1516-1523
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    • 2003
  • An inverse radiation analysis is presented for the estimation of the boundary emissivities for an absorbing, emitting, and scattering media with diffusely emitting and reflecting opaque boundaries. The finite-volume method is employed to solve the radiative transfer equation for a two-dimensional irregular geometry. A hybrid genetic algorithm is proposed for improving the efficiency of the genetic algorithm and reducing the effects of genetic parameters on the performance of the genetic algorithm. After verifying the performance of the proposed hybrid genetic algorithm, it is applied to inverse radiation analysis in estimating the wall emissivities in a two-dimensional irregular medium when the measured temperatures are given at only four data positions. The effect of measurement errors on the estimation accuracy is examined.

Optimal Time Slot Assignment Algorithm for Combined Unicast and Multicast Packets

  • Lee, Heyung-Sub;Joo, Un-Gi;Lee, Hyeong-Ho;Kim, Whan-Woo
    • ETRI Journal
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    • v.24 no.2
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    • pp.172-175
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    • 2002
  • This paper considers a packet-scheduling algorithm for a given combined traffic of unicast and multicast data packets and proposes a hybrid router with several dedicated buses for multicast traffic. Our objective is to develop a scheduling algorithm that minimizes schedule length for the given traffic in the hybrid router. We derive a lower bound and develop an optimal solution algorithm for the hybrid router.

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Optimal Design of Fuzzy-Neural Networkd Structure Using HCM and Hybrid Identification Algorithm (HCM과 하이브리드 동정 알고리즘을 이용한 퍼지-뉴럴 네트워크 구조의 최적 설계)

  • Oh, Sung-Kwun;Park, Ho-Sung;Kim, Hyun-Ki
    • The Transactions of the Korean Institute of Electrical Engineers D
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    • v.50 no.7
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    • pp.339-349
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    • 2001
  • This paper suggests an optimal identification method for complex and nonlinear system modeling that is based on Fuzzy-Neural Networks(FNN). The proposed Hybrid Identification Algorithm is based on Yamakawa's FNN and uses the simplified inference as fuzzy inference method and Error Back Propagation Algorithm as learning rule. In this paper, the FNN modeling implements parameter identification using HCM algorithm and hybrid structure combined with two types of optimization theories for nonlinear systems. We use a HCM(Hard C-Means) clustering algorithm to find initial apexes of membership function. The parameters such as apexes of membership functions, learning rates, and momentum coefficients are adjusted using hybrid algorithm. The proposed hybrid identification algorithm is carried out using both a genetic algorithm and the improved complex method. Also, an aggregated objective function(performance index) with weighting factor is introduced to achieve a sound balance between approximation and generalization abilities of the model. According to the selection and adjustment of a weighting factor of an aggregate objective function which depends on the number of data and a certain degree of nonlinearity(distribution of I/O data), we show that it is available and effective to design an optimal FNN model structure with mutual balance and dependency between approximation and generalization abilities. To evaluate the performance of the proposed model, we use the time series data for gas furnace, the data of sewage treatment process and traffic route choice process.

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Hybrid genetic-paired-permutation algorithm for improved VLSI placement

  • Ignatyev, Vladimir V.;Kovalev, Andrey V.;Spiridonov, Oleg B.;Kureychik, Viktor M.;Ignatyeva, Alexandra S.;Safronenkova, Irina B.
    • ETRI Journal
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    • v.43 no.2
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    • pp.260-271
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    • 2021
  • This paper addresses Very large-scale integration (VLSI) placement optimization, which is important because of the rapid development of VLSI design technologies. The goal of this study is to develop a hybrid algorithm for VLSI placement. The proposed algorithm includes a sequential combination of a genetic algorithm and an evolutionary algorithm. It is commonly known that local search algorithms, such as random forest, hill climbing, and variable neighborhoods, can be effectively applied to NP-hard problem-solving. They provide improved solutions, which are obtained after a global search. The scientific novelty of this research is based on the development of systems, principles, and methods for creating a hybrid (combined) placement algorithm. The principal difference in the proposed algorithm is that it obtains a set of alternative solutions in parallel and then selects the best one. Nonstandard genetic operators, based on problem knowledge, are used in the proposed algorithm. An investigational study shows an objective-function improvement of 13%. The time complexity of the hybrid placement algorithm is O(N2).

Improvement and Performance Analysis of Hybrid Anti-Collision Algorithm for Object Identification of Multi-Tags in RFID Systems (RFID 시스템에서 다중 태그 인식을 위한 하이브리드 충돌방지 알고리즘의 개선 및 성능 분석)

  • Choi, Tae-Jeong;Seo, Jae-Joon;Baek, Jang-Hyun
    • IE interfaces
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    • v.22 no.3
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    • pp.278-286
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    • 2009
  • The anti-collision algorithms to identify a number of tags in real-time in RFID systems are divided into the anti-collision algorithms based on the Framed slotted ALOHA that randomly select multiple slots to identify the tags, and the anti-collision algorithms based on the Tree-based algorithm that repeat the questions and answer process to identify the tags. In the hybrid algorithm which is combined the advantages of these algorithms, tags are distributed over the frames by selecting one frame among them and then identified by using the Query tree frame by frame. In this hybrid algorithm, however, the time of identifying all tags may increase if many tags are concentrated in a few frames. In this study, to improve the performance of the hybrid algorithm, we suggest an improved algorithm that the tags select a specific group of frames based on the earlier bits of the tag ID so that the tags are distribute equally over the frames. By using the simulation and mathematical analysis, we show that the suggested algorithm outperforms traditional hybrid algorithm from the viewpoint of the number of queries per frame and the time of identifying all tags.