• Title/Summary/Keyword: ALM Method

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Pre-Processing for Determining Acral Lentiginous Melanoma(ALM) (말단흑색점흑색종 판별을 위한 전처리 과정)

  • Ham, S.W.;Oho, B.H.;Yang, S.J.
    • Journal of Biomedical Engineering Research
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    • v.36 no.1
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    • pp.22-30
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    • 2015
  • Melanoma is originated from the melanocyte producing the melanin which determines the complexion, and it has the highest mortality among skin cancers. Acral lentiginous melanoma(ALM) arises from extremities such as hands, feet or fingernails. Since the appearance of ALM is different from melanoma on the body, conventional auto diagnosis systems for melanoma is inappropriate to detect ALM. Therefore, ALM is typically difficult to distinguish from general nevus, resulting in delayed diagnosis and bad prognosis. In this paper, we firstly introduce a determination method for ALM by dermatologists and propose a method to rotate dermoscopic images automatically as a pre-processing for facilitating the easy determination of ALM and to select the optimal value of the Gaussian differentiation filter parameter which is significant for precise pattern extraction using the scale space analysis. From experimental results, it is shown that there exists the consistency between empirical values of the Gaussian differential filter parameter and optimal values derived from the scale space analysis to distinguish nevus and ALM.

Maximum Torque Control of SynRM Drive with ALM-FNN Controller (ALM-FNN 제어기에 의한 SynRM 드라이브의 최대토크 제어)

  • Ko, Jae-Sub;Choi, Jung-Sik;Chung, Dong-Hwa
    • Journal of the Korean Institute of Illuminating and Electrical Installation Engineers
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    • v.20 no.10
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    • pp.47-57
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    • 2006
  • The paper is proposed maximum torque control of SynRM drive using adaptive teaming mechanism-fuzzy neural network(ALM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $^i{_d}$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled ALM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the ALM-FNN and ANN controller.

Numerical optimization via ALM method (ALM방법에 의한 수치해석적 최적화)

  • 김민수;이재원
    • Journal of the korean Society of Automotive Engineers
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    • v.11 no.2
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    • pp.24-33
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    • 1989
  • 본 고에서는 이러한 추세에 따라서, 보다 효율적인 optimization program에 대해서 소개하고자 한다. 사용한 최적화 알고리즘은 ALM(augmented lagrange multiplier) 방법을 적용해서 구속조건이 있는 문제를 구속조건이 없는 문제로 변환한 후, self-scaling BFGS(broydon-flecher-goldfarb-schanno)를 적용한다. BFGS의 각 descent 방향에서의 step 길이는, sequential search로 unimodal point를 구해서, golden section 방법으로 refine을 한후, cubic approximation을 적용해서 구한다.

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An Application of ALM-BFGS Algorithm for the Optimum Section Design of Composite Breakwaters (ALM-BFGS 알고리즘을 이용한 혼성방파제의 최적단면설계에 관한 연구)

  • Seo, Kyung Min;Ryu, Yeon Sun;Ryu, Cheong Ro
    • KSCE Journal of Civil and Environmental Engineering Research
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    • v.12 no.1
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    • pp.197-205
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    • 1992
  • For the optimal design of composite breakwaters, a computer program PROCOBRA is developed using the combined ALM-BFGS algorithm. A model formulation for the section design optimization problem of composite breakwaters is proposed where a concept of subsectional weighting factors is introduced in the objective function. Usability of the program is verified through a numerical example. From the study, it is found that the ALM-BFGS method is reliable and can be effectively applied for the design optimization of coastal structures. Compared with conventional design process, it is proved that the economical design of composite breakwaters is possible.

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A New Smoothing Method of Unstructured Viscous Grid for ALM Method (ALM 방법에 의한 비정렬 점성 격자의 유화 기법)

  • Lee, Bong-Ju;Kim, Byoung-Soo
    • 한국전산유체공학회:학술대회논문집
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    • 2008.03b
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    • pp.618-621
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    • 2008
  • In this paper a new smoothing method of unstructured viscous grid which can be useful when the ALM(Advacning Layer Method) method is used to generate volume grids of prism cells starting with unstructured triangular surface grids. According to the new method two layers of prism cells in the advancing direction which are found by the vector smoothing method are first generated, and then the position of nodes along the middle layer are adjusted by using spring analogy. It is found that the proposed method improves grid quality of the unstructured viscous volume grids for body shape with convex and concave corners.

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Computational enhancement to the augmented lagrange multiplier method for the constrained nonlinear optimization problems (구속조건식이 있는 비선형 최적화 문제를 위한 ALM방법의 성능향상)

  • 김민수;김한성;최동훈
    • Transactions of the Korean Society of Mechanical Engineers
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    • v.15 no.2
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    • pp.544-556
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    • 1991
  • The optimization of many engineering design problems requires a nonlinear programming algorithm that is robust and efficient. A general-purpose nonlinear optimization program IDOL (Interactive Design Optimization Library) is developed based on the Augmented Lagrange Mulitiplier (ALM) method. The ideas of selecting a good initial design point, using resonable initial values for Lagrange multipliers, constraints scaling, descent vector restarting, and dynamic stopping criterion are employed for computational enhancement to the ALM method. A descent vector is determined by using the Broydon-Fletcher-Goldfarb-Shanno (BFGS) method. For line search, the Incremental-Search method is first used to find bounds on the solution, then the bounds are reduced by the Golden Section method, and finally a cubic polynomial approximation technique is applied to locate the next design point. Seven typical test problems are solved to show IDOL efficient and robust.

Maximum Torque Control of IPMSM using ALM-FNN and MFC Controller (ALM-FNN 및 MFC 제어기를 이용한 IPMSM 최대토크 제어)

  • Jung, Byung-Jin;Ko, Jae-Sub;Choi, Jung-Sik;Jung, Chul-Ho;Kim, Do-Yeon;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2009.04b
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    • pp.26-28
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    • 2009
  • This paper proposes maximum torque control of IPMSM drive using adaptive teaming mechanism-fuzzy neural network (ALM-FNN) controller, model reference adaptive fuzzy tonal(MFC) and artificial neural network(ANN). This control method is applicable over the entire speed range which considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $i_d$ for maximum torque operation is derived. This paper considers the design and implementation of novel technique of high performance speed control for IPMSM using ALM-FNN, MFC and ANN controller. The proposed control algorithm is applied to IPMSM drive system controlled ALM-FNN, MFC and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper proposes the analysis results to verify the effectiveness of the ALM-FNN, MFC and ANN controller.

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Dynamic response optmization using approximate search (근사 선탐색을 이용한 동적 반응 최적화)

  • Kim, Min-Soo;Choi, Dong-hoon
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.4
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    • pp.811-825
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    • 1998
  • An approximate line search is presented for dynamic response optimization with Augmented Lagrange Multiplier(ALM) method. This study empolys the approximate a augmented Lagrangian, which can improve the efficiency of the ALM method, while maintaining the global convergence of the ALM method. Although the approximate augmented Lagragian is composed of only the linearized cost and constraint functions, the quality of this approximation should be good since an approximate penalty term is found to have almost second-order accuracy near the optimum. Typical unconstrained optimization algorithms such as quasi-Newton and conjugate gradient methods are directly used to find exact search directions and a golden section method followed by a cubic polynomial approximation is empolyed for approximate line search since the approximate augmented Lagrangian is a nonlinear function of design variable vector. The numberical performance of the proposed approach is investigated by solving three typical dynamic response optimization problems and comparing the results with those in the literature. This comparison shows that the suggested approach is robust and efficient.

A New Penalty Parameter Update Rule in the Augmented Lagrange Multiplier Method for Dynamic Response Optimization

  • Kim, Min-Soo;Choi, Dong-Hoon
    • Journal of Mechanical Science and Technology
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    • v.14 no.10
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    • pp.1122-1130
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    • 2000
  • Based on the value of the Lagrange multiplier and the degree of constraint activeness, a new update rule is proposed for penalty parameters of the ALM method. The theoretical exposition of this suggested update rule is presented by using the algorithmic interpretation and the geometric interpretation of the augmented Lagrangian. This interpretation shows that the penalty parameters can effect the performance of the ALM method. Also, it offers a lower limit on the penalty parameters that makes the augmented Lagrangian to be bounded. This lower limit forms the backbone of the proposed update rule. To investigate the numerical performance of the update rule, it is embedded in our ALM based dynamic response optimizer, and the optimizer is applied to solve six typical dynamic response optimization problems. Our optimization results are compared with those obtained by employing three conventional update rules used in the literature, which shows that the suggested update rule is more efficient and more stable than the conventional ones.

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Maximum Torque Control of SynRM Drive with Artificial Intelligent Controller (인공지능 제어기에 의한 SynRM 드라이브의 최대토크 제어)

  • Ko, Jae-Sub;Choi, Jung-Sik;Kim, Kil-Bong;Chung, Dong-Hwa
    • Proceedings of the KIEE Conference
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    • 2006.10c
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    • pp.257-259
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    • 2006
  • The paper is proposed maximum torque control of SynRM drive using adaptive learning mechanism-fuzzy neural network(ALM-FNN) controller and artificial neural network(ANN). The control method is applicable over the entire speed range and considered the limits of the inverter's current and voltage rated value. For each control mode, a condition that determines the optimal d-axis current $^{i}d$ for maximum torque operation is derived. The proposed control algorithm is applied to SynRM drive system controlled ALM-FNN and ANN controller, the operating characteristics controlled by maximum torque control are examined in detail. Also, this paper is proposed the analysis results to verify the effectiveness of the ALM-FNN and ANN controller.

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