• 제목/요약/키워드: Optimization and identification

검색결과 419건 처리시간 0.026초

Neural Model Predictive Control for Nonlinear Chemical Processes

  • Song, Jeong-Jun;Park, Sunwon
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1993년도 Fifth International Fuzzy Systems Association World Congress 93
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    • pp.899-902
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    • 1993
  • A neural model predictive control strategy combining a neural network for plant identification and a nonlinear programming algorithm for solving nonlinear control problems is proposed. A constrained nonlinear optimization approach using successive quadratic programming combined with neural identification network is used to generate the optimum control law for complex continuous chemical reactor systems that have inherent nonlinear dynamics. The neural model predictive controller (MNPC) shows good performances and robustness. To whom all correspondence should be addressed.

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Damage assessment of beams from changes in natural frequencies using ant colony optimization

  • Majumdar, Aditi;De, Ambar;Maity, Damodar;Maiti, Dipak Kumar
    • Structural Engineering and Mechanics
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    • 제45권3호
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    • pp.391-410
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    • 2013
  • A numerical method is presented here to detect and assess structural damages from changes in natural frequencies using Ant Colony Optimization (ACO) algorithm. It is possible to formulate the inverse problem in terms of optimization and then to utilize a solution technique employing ACO to assess the damage/damages of structures using natural frequencies. The laboratory tested data has been used to verify the proposed algorithm. The study indicates the potentiality of the developed code to solve a wide range of inverse identification problems in a systematic manner. The developed code is used to assess damages of beam like structures using a first few natural frequencies. The outcomes of the simulated results show that the developed method can detect and estimate the amount of damages with satisfactory precision.

SEQUENTIAL MINIMAL OPTIMIZATION WITH RANDOM FOREST ALGORITHM (SMORF) USING TWITTER CLASSIFICATION TECHNIQUES

  • J.Uma;K.Prabha
    • International Journal of Computer Science & Network Security
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    • 제23권4호
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    • pp.116-122
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    • 2023
  • Sentiment categorization technique be commonly isolated interested in threes significant classifications name Machine Learning Procedure (ML), Lexicon Based Method (LB) also finally, the Hybrid Method. In Machine Learning Methods (ML) utilizes phonetic highlights with apply notable ML algorithm. In this paper, in classification and identification be complete base under in optimizations technique called sequential minimal optimization with Random Forest algorithm (SMORF) for expanding the exhibition and proficiency of sentiment classification framework. The three existing classification algorithms are compared with proposed SMORF algorithm. Imitation result within experiential structure is Precisions (P), recalls (R), F-measures (F) and accuracy metric. The proposed sequential minimal optimization with Random Forest (SMORF) provides the great accuracy.

Optimization study of a clustering algorithm for cosmic-ray muon scattering tomography used in fast inspection

  • Hou, Linjun;Huo, Yonggang;Zuo, Wenming;Yao, Qingxu;Yang, Jianqing;Zhang, Quanhu
    • Nuclear Engineering and Technology
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    • 제53권1호
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    • pp.208-215
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    • 2021
  • Cosmic-ray muon scattering tomography (MST) technology is a new radiation imaging technology with unique advantages. As the performance of its image reconstruction algorithm has a crucial influence on the imaging quality, researches on this algorithm are of great significance to the development and application of this technology. In this paper, a fast inspection algorithm based on clustering analysis for the identification of the existence of nuclear materials is studied and optimized. Firstly, the principles of MST technology and a binned clustering algorithm were introduced, and then several simulation experiments were carried out using Geant4 toolkit to test the effects of exposure time, algorithm parameter, the size and structure of object on the performance of the algorithm. Based on these, we proposed two optimization methods for the clustering algorithm: the optimization of vertical distance coefficient and the displacement of sub-volumes. Finally, several sets of experiments were designed to validate the optimization effect, and the results showed that these two optimization methods could significantly enhance the distinguishing ability of the algorithm for different materials, help to obtain more details in practical applications, and was therefore of great importance to the development and application of the MST technology.

적응형 계층적 공정 경쟁 기반 병렬유전자 알고리즘의 구현 및 비선형 시스템 모델링으로의 적용 (Implementation of Adaptive Hierarchical Fair Com pet ion-based Genetic Algorithms and Its Application to Nonlinear System Modeling)

  • 최정내;오성권;김현기
    • 대한전기학회:학술대회논문집
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    • 대한전기학회 2006년 학술대회 논문집 정보 및 제어부문
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    • pp.120-122
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    • 2006
  • The paper concerns the hybrid optimization of fuzzy inference systems that is based on Hierarchical Fair Competition-based Parallel Genetic Algorithms (HFCGA) and information data granulation. The granulation is realized with the aid of the Hard C-means clustering and HFCGA is a kind of multi-populations of Parallel Genetic Algorithms (PGA), and it is used for structure optimization and parameter identification of fuzzy model. It concerns the fuzzy model-related parameters such as the number of input variables to be used, a collection of specific subset of input variables, the number of membership functions, the order of polynomial, and the apexes of the membership function. In the hybrid optimization process, two general optimization mechanisms are explored. Thestructural optimization is realized via HFCGA and HCM method whereas in case of the parametric optimization we proceed with a standard least square method as well as HFCGA method as well. A comparative analysis demonstrates that the proposed algorithm is superior to the conventional methods.

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입자 군집 최적화를 이용한 FCM 기반 퍼지 모델의 동정 방법론 (Identification Methodology of FCM-based Fuzzy Model Using Particle Swarm Optimization)

  • 오성권;김욱동;박호성;손명희
    • 전기학회논문지
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    • 제60권1호
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    • pp.184-192
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    • 2011
  • In this study, we introduce a identification methodology for FCM-based fuzzy model. The two underlying design mechanisms of such networks involve Fuzzy C-Means (FCM) clustering method and Particle Swarm Optimization(PSO). The proposed algorithm is based on FCM clustering method for efficient processing of data and the optimization of model was carried out using PSO. The premise part of fuzzy rules does not construct as any fixed membership functions such as triangular, gaussian, ellipsoidal because we build up the premise part of fuzzy rules using FCM. As a result, the proposed model can lead to the compact architecture of network. In this study, as the consequence part of fuzzy rules, we are able to use four types of polynomials such as simplified, linear, quadratic, modified quadratic. In addition, a Weighted Least Square Estimation to estimate the coefficients of polynomials, which are the consequent parts of fuzzy model, can decouple each fuzzy rule from the other fuzzy rules. Therefore, a local learning capability and an interpretability of the proposed fuzzy model are improved. Also, the parameters of the proposed fuzzy model such as a fuzzification coefficient of FCM clustering, the number of clusters of FCM clustering, and the polynomial type of the consequent part of fuzzy rules are adjusted using PSO. The proposed model is illustrated with the use of Automobile Miles per Gallon(MPG) and Boston housing called Machine Learning dataset. A comparative analysis reveals that the proposed FCM-based fuzzy model exhibits higher accuracy and superb predictive capability in comparison to some previous models available in the literature.

3-자유도 헬리콥터 시스템의 입자군집최적화 기법을 이용한 시스템 식별 (A Study on Identification using Particle Swarm Optimization for 3-DOF Helicopter System)

  • 이호운;김태우;김태형
    • 한국지능시스템학회논문지
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    • 제25권2호
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    • pp.105-110
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    • 2015
  • 본 연구는 Quanser사의 3-자유도 헬리콥터 시스템에 대한 종래의 선형 수리 모델을 개선한 수리 모델을 제안하고, 실험을 통해 제안된 수리 모델을 기반으로 설계된 제어기의 제어 성능을 종래의 수리 모델을 기반으로 설계된 제어기의 제어 성능과 비교함으로써 그 타당성을 검증한다. 이에 대한 연구 진행 과정은 다음과 같다. 첫째, 3-자유도 헬리콥터 시스템의 동 특성을 분석하고, 종래의 선형 수리 모델을 구축한다. 둘째, 종래의 수리 모델의 구축을 위해 수행된 선형화 과정에서 제거된 비선형적 요소들을 파악한다. 그리고 이 제거된 비선형적 요소들에 대응하는 파라미터들을 추가하여 개선된 수리 모델을 구축한다. 이 때, 수리 모델을 구축하기 위해 메타 휴리스틱 전역 최적화 기법인 입자군집최적화 알고리즘을 이용한다. 마지막으로, 제안된 모델을 기반으로 제어기를 설계하고, 이를 종래의 수리 모델을 기반으로 설계된 제어기의 제어 성능을 비교하여 제안된 수리 모델의 타당성을 검증한다.

RFID 태그 개수 추정 방법 및 질의 시간 최소화 방안 (RFID Tag Number Estimation and Query Time Optimization Methods)

  • 우경문;김종권
    • 한국정보과학회논문지:정보통신
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    • 제33권6호
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    • pp.420-427
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    • 2006
  • 무선인식(RFID) 시스템은 기존의 바코드 시스템을 대체할 뿐만 아니라 제조, 물류, 서비스 산업 등을 변화시킬 차세대 핵심 기술 중의 하나이다. RFID 시스템은 무선으로 초당 수 백개까지의 태그 정보를 인식할 수 있다. 태그 인식은 리더(reader)가 각 라운드 별로 정한 프레임 동안 태그들이 자신의 ID를 임의 전송함으로써 이루어진다. 태그 인식 시간을 감소시키려면 태그 수를 감안한 적절한 크기의 프레임을 할당해야 한다. 본 논문에서는 RFID 시스템에서 질의 시간을 최소화 할 수 있는 방법을 제안하였다. 먼저 태그 개수를 단순하면서도 효율적으로 추정하는 방법을 제안하고, 이를 이용하여 각 라운드 별로 최적 프레임 길이를 구하여 전체 질의 시간을 최소화하는 방법을 개발하였다. 기존에 제안된 방법과 성능 비교를 수행하여 본 논문에서 제안하는 태그 수 추정 방법이 기존 방법보다 더 정확하고 효율적임을 관찰하였고 최적 프레임 길이 결정 문제에 또한 간단한 Greedy방법이 복잡한 최적 프레임 계산기법과 비슷한 성능을 가진다는 것을 확인하였다.

On-load Parameter Identification of an Induction Motor Using Univariate Dynamic Encoding Algorithm for Searches

  • Kim, Jong-Wook;Kim, Nam-Gun;Choi, Seong-Chul;Kim, Sang-Woo
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 2004년도 ICCAS
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    • pp.852-856
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    • 2004
  • An induction motor is one of the most popular electrical apparatuses owing to its simple structure and robust construction. Parameter identification of the induction motor has long been researched either for a vector control technique or fault detection. Since vector control is a well-established technique for induction motor control, this paper concentrates on successive identification of physical parameters with on-load data for the purpose of condition monitoring and/or fault detection. For extracting six physical parameters from the on-load data in the framework of the induction motor state equation, unmeasured initial state values and profiles of load torque have to be estimated as well. However, the analytic optimization methods in general fail to estimate these auxiliary but significant parameters owing to the difficulty of obtaining their gradient information. In this paper, the univariate dynamic encoding algorithm for searches (uDEAS) newly developed is applied to the identification of whole unknown parameters in the mathematical equations of an induction motor with normal operating data. Profiles of identified parameters appear to be reasonable and therefore the proposed approach is available for fault diagnosis of induction motors by monitoring physical parameters.

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FUZZY IDENTIFICATION BY MEANS OF AUTO-TUNING ALGORITHM AND WEIGHTING FACTOR

  • Park, Chun-Seong;Oh, Sung-Kwun;Ahn, Tae-Chon;Pedrycz, Witold
    • 한국지능시스템학회:학술대회논문집
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    • 한국퍼지및지능시스템학회 1998년도 The Third Asian Fuzzy Systems Symposium
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    • pp.701-706
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    • 1998
  • A design method of rule -based fuzzy modeling is presented for the model identification of complex and nonlinear systems. The proposed rule-based fuzzy modeling implements system structure and parameter identification in the efficient form of " IF..., THEN,," statements. using the theories of optimization and linguistic fuzzy implication rules. The improved complex method, which is a powerful auto-tuning algorithm, is used for tuning of parameters of the premise membership functions in consideration of the overall structure of fuzzy rules. The optimized objective function, including the weighting factors, is auto-tuned for better performance of fuzzy model using training data and testing data. According to the adjustment of each weighting factor of training and testing data, we can construct the optimal fuzzy model from the objective function. The least square method is utilized for the identification of optimum consequence parameters. Gas furance and a sewage treatment proce s are used to evaluate the performance of the proposed rule-based fuzzy modeling.

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