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International Conference on Design, Manufacturing and Mechatronics (ICDMM)

作者： Bu, He-Nan Yan, Zhu-Wen Zhang, Cheng-Ming Zhang, Dian-Hua Northeastern Univ State Key Lab Rolling & Automat Shenyang Liaoning Peoples R China Bengang Steel Plates Co Ltd High Strength Steel Dev Dept Shenzhen Liaoning Peoples R China

ISBN: (纸本)9783038351016

In order to improve the setting accuracy of rolling force model, a comprehensive parameters adaptive objective function of rolling force was established. During the adaptive process, the adaptive coefficients of friction coefficient and deformation resistance were taken as the optimized parameters, and the Rosenbrock algorithm was used to search the optimal solution of the objective function. The proposed adaptive method has been applied successfully to a 1450mm 5-stand tandem cold mill. Application results show that the forecast accuracy of rolling force model has been improved significantly.

关键词： Tandem cold mill objective function Rolling force model Optimization algorithm Adaption

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An objective function based technique for devignetting fundus imagery using MST

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Informatics in Medicine Unlocked 2019年 14卷 82-91页

作者： Shamsudeen, Fousia M. Raju, G. School of Computer Science MG University Kottayam India Department of Computer Applications TKM College of Engineering India Department of Computer Science and Engineering Faculty of Engineering Christ (deemed to be University) Kanminike Kumbalagod Post Bengaluru 560074 India

Fundus photography is a powerful imaging modality that is utilized for detecting macular degeneration, retinal neoplasms, choroid disturbances, glaucoma and diabetic retinopathy. As the illumination source in fundus imaging is situated at the center of the fundus camera, the illumination at the peripheral regions of the images would be relatively less than the center, which is termed vignetting. Vignetting adversely affects the performance of computerized methods for analyzing fundus imagery. A devignetting method for fundus imagery based on the Modified Sigmoid Transform (MST) is proposed in this paper. Gain (A) and centering parameter (α) of MST have a crucial influence on its performance. For low values of the gain, local contrast is penalized, and the overall dynamic range is compressed. When the value of gain is very high, the images after the illumination correction will have a washed out appearance. The optimum value of gain is determined in this paper from an objective method based on two statistical indices, Average Gradient of Illumination Component (AGIC) and Error of Enhancement (EME). MST with gain value defined via objective methods is able to correct the uneven illumination in fundus images without penalizing the local contrast. The proposed method is compared with illumination equalization model, homomorphic filtering and Adaptive Gamma Correction (AGC) and was found to be superior in terms of ‘naturality’ uniformity of background illumination, and computational speed. © 2018

关键词： Average gradient of illumination component Devignetting Error of enhancement Fundus imagery Illumination correction Modified sigmoid transform (MST) objective function

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Minimization algorithms making use of non-quadratic properties of the objective function

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IMA Journal of Applied Mathematics (Institute of Mathematics and Its Applications) 1971年第3期8卷 315-327页

作者： Biggs, M.C. Numerical Optimization Centre Hatfield Polytechnic Hatfield Hertfordshire England United Kingdom

This paper proposes modifications to the matrix updating formulae used in the Fletcher-Powell (1963), Broyden (1970) and Fletcher (1970) methods for function minimization, and discusses some properties of these modified formulae. A function minimization algorithm incorporating the new expressions has been programmed and the results of tests with some well-known functions are reported. © 1971 by Academic Press Inc. (London) Limited.

关键词： function MINIMISATION MODIFICATION formula objective function algorithms Modified

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Study on the properties of flatness error objective function

Study on the properties of flatness error objective function

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3rd International Symposium on Precision Mechanical Measurements

作者： Liu Ping Wang Sha Northeastern Univ Sch Mech Engn & Automat Shenyang 110004 Liaoning Peoples R China China Explorat Engn Bur Geophys Explorat Bur Baoding 071051 Peoples R China

ISBN: (纸本)0819463515

Optimization algorithms are generally used to seek the minimal values of form error objective functions by iteration when a microcomputer is used to evaluate form errors of machine components by the minimum zone evaluation methods. The properties of such objective functions are very important for seeking the minimum zone values of error quickly and reliably. In this article, the unconstrained optimization model is established for assessing flatness errors by the minimum zone assessment method. The properties of the corresponding objective function are thoroughly researched. On the basis of the modem theory on convex functions, it is strictly proved that the established flatness objective function by the minimum zone assessment method is a continuous, non-differentiable and convex function defined on the two-dimensional Euclidean space R-2. Therefore, the global minimal value of the objective function is unique and any of its minimal point must be its global minimal point. Thus, any existing optimization algorithm, as long as it is convergent, can be used to solve the objective function to get the reliable minimum zone flatness errors, without the possibility of seeking a value which is not in accord with the minimum zone for flatness. Two examples are given to verify the theoretical results presented.

关键词： metrology precision mechanical measurement form error flatness objective function optimization convex function

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Selection of the objective function of reduction parameter optimization algorithm, and its impact on the properties of reduced MIMO models 20

Selection of the objective function of reduction parameter o...

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20th International Conference on Methods and Models in Automation and Robotics (MMAR)

作者： Rydel, Marek Stanislawski, Wlodzimierz Opole Univ Technol Dept Elect Control & Comp Engn Opole Poland Univ Appl Sci Inst Comp Sci Nysa Poland

ISBN: (纸本)9781479987016

This article presents a range of approximation error measures for reduced mathematical MIMO models of controlled objects. These measures can be of use in evaluations of reduction quality. The impact of selection of a particular approximation error measure as the objective function of the reduction parameter optimization algorithm on the frequency characteristics of the reduced model was analyzed. Particular emphasis was given to those cases where the individual channels of a MIMO model differ significantly from one another. The results are presented on the example of a one-phase zone evaporating tubes model of a BP-1150 steam boiler.

关键词： objective function multiple input multiple output systems Approximation error IMPACT PROPERTIES Parameter optimization frequency characteristic reduced model controlled object COHERENT TUBE MODEL annonacin-A-one

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OF-ECF: A New Optimization of the objective function for Parent Selection in RPL 15

OF-ECF: A New Optimization of the Objective Function for Par...

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15th International Conference on Wireless and Mobile Computing, Networking and Communications (WiMob)

作者： Lamaazi, Hanane El Ahmadi, Adnan Benamar, Nabil Jara, Antonio J. Moulay Ismail Univ Meknes Fac Sci Meknes Morocco Ibn Tofail Univ Natl Sch Appl Sci Kenitra Morocco Moulay Ismail Univ Meknes Sch Technol Meknes Morocco Univ Appl Sci Western Switzerland HES SO Sierre Vallais Switzerland

ISBN: (纸本)9781728133164

The RPL routing protocol is designed to respond to the requirements of a large range of Low-power and Lossy Networks (LLNs). RPL uses an objective function (OF) to build the route toward a destination based on routing metrics. Considering only a single metric, some network performances can be improved while others may be degraded. In this paper, we present a flexible objective function based on Expected Transmission Count (ETX), Consumed Energy and Forwarding Delay (OF-ECF) built on a combination of metrics using an additive method. The main goal of this proposed solution is to balance energy consumption and minimize the average delay. To improve the reliability of the network, a flexible routing scheme that provides the diversity of paths and a higher availability is presented. Simulations results show that the new objective function OF-ECF outperforms the OF-FUZZY, and the standards OF0 and MRHOF. In terms of network lifetime and reliability.

关键词： RPL objective function ETX energy consumption forwarding delay

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TAOF: Traffic Aware objective function for RPL-based Networks

TAOF: Traffic Aware Objective Function for RPL-based Network...

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Global Information Infrastructure and Networking Symposium (GIIS)

作者： Ji, Chenyang Koutsiamanis, Remous-Aris Montavont, Nicolas Chatzimisios, Periklis Dujovne, Diego Papadopoulos, Georgios Z. Alexander TEI Thessaloniki CSSN Res Lab Thessaloniki Greece UBL IRISA IMT Atlantique Nantes France Univ Diego Portales Escuela Informat & Telecomunicac Santiago Chile

ISBN: (纸本)9781538672723

Within the context of the Internet of Things (IoT), the distance-vector IPv6 Routing Protocol for Low-power and Lossy Networks (RPL) is one of the most popular choices for the network routing layer. Within RPL, distance calculation is abstracted by the objective function (OF) and two OF implementations have been standardized, namely OF0 and MRHOF. However, these OFs build network topologies where bottleneck nodes may suffer from excessive unbalanced traffic load. The load distribution problem is a major issue for existing OFs defined in RPL because it decreases network performance and the network's lifetime. In this paper, we propose a new OF called the Traffic Aware objective function (TAOF), which balances the traffic load that each node processes in order to ensure node lifetime maximization. To implement this OF, we altered the DIO message format, introduced a new RPL metric, named Traffic Rate, and used a new parent selection algorithm. Simulation experiments have been conducted to examine the performance of our proposal. The results show that TAOF achieves enhanced performance in terms of Packet Delivery Ratio (PDR) and that it builds more stable networks with fewer parent changes.

关键词： Internet of Things Low-power and Lossy Networks LLNs RPL Load Balancing objective function

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The Cutter Speed Determination of CNC Laser Cutting Machines for Precise Calculation of objective function of Tool Path Problem 2

The Cutter Speed Determination of CNC Laser Cutting Machines...

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2nd International Conference on Industrial Engineering, Applications and Manufacturing (ICIEAM)

作者： Tavaeva, A. F. Petunin, A. A. Ural Fed Univ UrFU Ekaterinburg Russia

ISBN: (纸本)9781509013227

This paper deals with problems of optimization of tool path for CNC thermal cutting machines. We have chosen basic restrictions, for example, selection of piercing, selection of parts cutting sequence. They must be considered during development of NC programs. The paper considers optimization of tool path for CNC thermal cutting machines, namely minimization of cutting time and cost. The accuracy of objective function parameters calculation is investigated. The paper also reviews the operation speed of cutting tool for CNC laser cutting machines. It is usually a constant value, but conducted researches show that operation speed of cutting tool depends on some parameters, such as number of frames in NC programs, configurations, geometries and dimensions of parts. The correction parameters for operation speed of cutting tool for rectangle parts were obtained in previous works. The parts of various configurations, geometries and overall dimensions are also considered in this paper. Based on received results, average correction coefficients for operation speed of cutting tool have been obtained. These coefficients may be taken into account in order to calculate the objective function more accurately. In future work, the examples of tool path calculation will be considered taking into account the computation of objective functions with correction coefficients and without them.

关键词： CNC thermal cutting machines thermal deformation of material tool path problem optimization objective function optimization working speed of cutter parameters of objective function

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Effect of the Different objective function Formulations on DOCR Setting Optimization

Effect of the Different Objective Function Formulations on D...

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7th IEEE Region10 Humanitarian Technology Conference (IEEE R10 HTC)

作者： Senarathna, T. S. S. Boralessa, M. A. K. S. Hemapala, K. T. M. Udayanga Univ Moratuwa Dept Elect Engn Moratuwa Sri Lanka

ISBN: (纸本)9781728108346

Modern distribution networks are more inclined to integrate distributed energy generation (DEG) into their systems. Protection problems occur when using conventional protection solutions on these DEG integrated networks. Optimal coordination of overcurrent relays while minimizing the operating time is one of the popular research interests. Optimization algorithms are used to solve this multi-objective constrained optimization problem. In this paper, various methods of problem formulation in literature are compared to observe their effect on final relay operating times.

关键词： Distributed Generation objective function Genetic algorithm Near-end faults Far-end faults Protection coordination

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A novel opportunistic Fuzzy logic based objective function for the Routing Protocol for Low-Power and Lossy Networks 15

A novel opportunistic Fuzzy logic based objective function f...

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15th IEEE International Wireless Communications and Mobile Computing Conference (IEEE IWCMC)

作者： Kechiche, Ines Bousnina, Ines Samet, Abdelaziz Univ Carthage Tunisian Polytech Sch SERCOM Lab La Marsa Tunisia

ISBN: (纸本)9781538677476

Low power and lossy networks (LLNs) are constrained networks that need specific routing protocols able to meet application requirements such as latency and reliability. RPL was designed by the IETF ROLL working group for such challenging networks. It defines an objective function (OF) that can operate according to a set of metrics and constraints to make nodes select best parents and then construct paths. Considering the vast areas of applications for RPL, used metrics and constraints combinations was left an open issue for implementation. In this paper, we propose an opportunistic fuzzy logic based OF (OPP-FL) that takes into consideration a novel routing metric measuring neighbor load in addition to traditional IETF ROLL specified metrics. Our proposed scheme combine through a fuzzy logic process the traditional expected transmission count (ETX) and Hop Count (HC) metrics to proposed Children Number (CN) metric. Simulation results reveal that compared to the based ETX OF, namely MRHOF and the OF-EC a fuzzy logic based OF has achieved better performances in terms of PDR and acceptable results in terms of delay when the network size expands without inducing high traffic overhead.

关键词： RPL objective function Fuzzy Logic ETX Hop Count Children Number

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