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parametric modeling the human calves for evaluation and design of medical compression stockings

COMPUTER METHODS AND PROGRAMS IN BIOMEDICINE 2020年 194卷 105515-105515页

作者： Wang Xi Yang Bao Li Qiao Guo Xia Tao Xiaoming Hong Kong Polytech Univ Inst Text & Clothing Kowloon Hong Kong Peoples R China Donghua Univ Coll Informat Sci & Technol Shanghai Peoples R China Donghua Univ Coll Text Shanghai Peoples R China Hong Kong Polytech Univ Multidisciplinary Div Bioengn Kowloon Hong Kong Peoples R China

Background and objective: Accurate dose of compression imposed by functional compression garments, such as medical compression stockings, is critical for medical treatment or rehabilitation. To evaluate or provide fitted compression stockings for individuals, the real curved calf shapes other than just anthropometric parameters are required. Methods: This paper proposes and verifies a simple 3D parametric model of human calf that can fast and efficiently construct representative calves for evaluation or size-design purposes. Instead of selecting feature points, shape parameters were used to characterize the real calves. Results: Based on principal component analysis and a database of 220 scanned Chinese subjects, the proposed parametric model was found as capable of largely reducing the data complexity to only the 1st order principal component with a major variance percentage of as high as 96%. A methodological framework of parametric modeling was then proposed. Results show that the proposed parametric model and method can fast produce valid representative shapes of patients' calves, with which commercial stockings can be evaluated and customized stockings can be designed. Conclusions: It can be concluded that the proposed parametric model and method can highly boost evaluation/size customization of MCSs, and will also inspire the research on customization of other compression garments. (c) 2020 Published by Elsevier B.V.

关键词： parametric modeling 3D scan Customized design Medical compression stockings

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parametric modeling of Circuit Model for AC Glow Discharge in Air

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Transactions of Nanjing University of Aeronautics and Astronautics 2018年第4期35卷 710-718页

作者： Yu Bing Yuan Pei Shen Enyu Shu Wenjun Jiangsu Province Key Laboratory of Aerospace Power Systems College of Energy and Power EngineeringNanjing University of Aeronautics and Astronautics Nanjing 210016 P.R. China

In the parametric modeling of the circuit model for glow discharge in air,a new method for the design of glow discharge circuit model is *** new circuit model is an important reference for the design of plasma power supply,the simulation of glow discharge plasma actuator and the simulation of glow discharge plasma *** modeling approach consists in developing an electrical model of the glow discharge in air based on circuit *** structure of the circuit model is established according to the theoretical analysis and the experimental *** the parameters of the circuit model are obtained based on the circuit ***,the circuit model is verified by comparing the simulation current with the experimental *** model takes into account the whole framework of the air glow discharge including the sheath and the plasma *** built circuit model is feasible and reliable,thus being instructive for the investigation of the glow discharge in air.

关键词： parametric modeling glow discharge circuit model OrCAD

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parametric modeling of speech by complex AM and FM signals

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DIGITAL SIGNAL PROCESSING 2007年第6期17卷 1055-1064页

作者： Sircar, Pradip Saini, Rakesh K. Indian Inst Technol Dept Elect Engn Kanpur 208016 Uttar Pradesh India

Complex AM and FM signal models can be used for parametric modeling of speech signals. Complex AM signal model has been found to be suitable for voiced speech phonemes, whereas complex FM signal model can be used for representation of unvoiced speech phonemes. This article explains the basic principles of parameter estimation of these two models, and presents techniques for fast on-line processing of speech data and automated model fitting. (c) 2006 Elsevier Inc. All rights reserved.

关键词： parametric modeling speech signals complex AM signal complex FM signal automated model fitting

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parametric modeling of an electromagnetic compression device with the proper generalized decomposition

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INTERNATIONAL JOURNAL OF MATERIAL FORMING 2016年第1期9卷 101-113页

作者： Heuze, Thomas Leygue, Adrien Racineux, Guillaume Ecole Cent Nantes Res Inst Civil & Mech Engn GeM CNRS UMR 6183 1 Rue Noe F-44321 Nantes France

Optimization of forming processes seeks an optimal choice of many process parameters. In Electromagnetic Material Forming (EMF), parameters associated to the geometry of the forming device or related to the generation of the pulsed currents have to be set, and are of primary importance to achieve the proper geometry of the formed part. Usual optimization procedures proceed by defining a trial choice of the set of parameters and then evaluate the optimality of a given cost function computed from a direct analysis. This iterative process requires many assessments of the cost function and may lead to a prohibitive computation cost since the direct analysis may involve a structural analysis. Others approaches have been proposed to circumvent this problem;based on a separated representation of the solution, the Proper Generalized Decomposition allows for a parametric resolution by introducing optimization parameters as extra-coordinates of the problem, hence the optimization procedure reduces to a simple post-treatment of the multidimensional numerical solution. The aim of this work is to develop a numerical tool dedicated to the optimization of the design of an electromagnetic compression device. This tool should enable to optimize process parameters of the generator and geometrical parameters of the electromagnetic forming device by solving the set of electromagnetic equations in quasistatics. To this end, we take advantage of the Proper Generalized Decomposition (PGD) to perform a parametric resolution. We show solutions computed with a parameterization of the discharged current, and with a parameterization of the geometry considering a multi-layered structure. Finally, an example of optimization procedure is shown on the latter solution, seeking the configuration maximising the radial component of the resultant compression force applied on the part to be formed.

关键词： parametric modeling optimization electromagnetic compression device Proper generalized decomposition

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parametric modeling of Microwave Components Using Adjoint Neural Networks and Pole-Residue Transfer Functions With EM Sensitivity Analysis

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IEEE TRANSACTIONS ON MICROWAVE THEORY AND TECHNIQUES 2017年第6期65卷 1955-1975页

作者： Feng, Feng Gongal-Reddy, Venu-Madhav-Reddy Zhang, Chao Ma, Jianguo Zhang, Qi-Jun Tianjin Univ Sch Elect Informat Engn Tianjin 300072 Peoples R China Carleton Univ Dept Elect Ottawa ON K1S 5B6 Canada

This paper proposes a pole-residue-based adjoint neuro-transfer function (neuro-TF) technique with electromagnetic (EM) sensitivity analysis for parametric modeling of EM behavior of microwave components with respect to changes in geometrical parameters. The purpose is to increase model accuracy by utilizing EM sensitivity information and to speed up model development by reducing the number of training data required for developing the model. The proposed parametric model consists of original and adjoint pole-residue based neuro-TF models. New formulations are derived for calculating the second-order derivatives for training the adjoint pole-residue-based neuro-TF model. An advanced pole-residue tracking technique is proposed to exploit the sensitivity information to track the splitting of poles as geometrical parameters change. This pole-residue tracking technique allows the model to bridge the differences of the orders of transfer function over different regions of the geometrical parameters, and ultimately form smooth and continuous functions between the pole/residues and the geometrical variables. The proposed technique addresses the challenges of tracking pole splitting when training data are limited. By exploiting the sensitivity information, the proposed technique can speed up the model development process over the existing pole-residue parametric modeling method which does not use sensitivity analysis.

关键词： Electromagnetic (EM) neural network parametric modeling sensitivity analysis transfer function

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parametric modeling and multiobjective crashworthiness design optimization of a new front longitudinal beam

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STRUCTURAL AND MULTIDISCIPLINARY OPTIMIZATION 2019年第5期59卷 1789-1812页

作者： Duan, Libin Jiang, Haobin Geng, Guoqing Zhang, Xuerong Li, Zhanjiang Jiangsu Univ Sch Automot & Traff Engn Zhenjiang 212013 Jiangsu Peoples R China Nanjing Yueboo Power Syst Co Ltd Nanjing Jiangsu Peoples R China

The front longitudinal beam (FLB) is the most important energy-absorbing and crashing force-transmitting structure of a vehicle under front-impact collision. For better weight reduction and crashworthiness of the FLB, a new structure, variable rolled blank-variable cross-sectional shape FLB (VRB-VCS FLB), is proposed. It has both the continuous variation of thickness and variable cross-sectional shape in space. As the thickness distribution and cross-sectional shape change continuously, the proposed structure evolves into three distinct forms, i.e., the uniform-thickness FLB, variable rolled blank FLB, and variable cross-sectional shape FLB. However, literature on parametric modeling and crashworthiness design optimization of the VRB-VCS FLB is very limited. This paper proposes a parametric modeling method of VRB-VCS FLB with manufacturing constraints. Multiobjective crashworthiness design optimization is performed to explore the lightweightness and crashworthiness performance of the VRB-VCS FLB. Firstly, thickness distribution and cross-sectional shape parameters are defined. Secondly, local parametric subsystem front-impact model is established to balance accuracy and efficiency. Thirdly, a multiobjective optimization model of VRB-VCS FLB is constructed. Finally, a fully automated design of experiment platform is established to improve the data collection efficiency, and epsilon-support vector regression technique and non-dominated sorting genetic algorithm II are utilized to search the Pareto optimal frontier. The numerical results show that the lightweightness and crashworthiness of the VRB-VCS FLB are significantly improved when compared with the uniform-thickness FLB.

关键词： parametric modeling Multiobjective crashworthiness optimization Front longitudinal beam (FLB) Variable rolled blank (VRB) Variable cross-sectional shape (VCS)

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parametric modeling of the intervertebral disc space in 3D: Application to CT images of the lumbar spine

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COMPUTERIZED MEDICAL IMAGING AND GRAPHICS 2014年第7期38卷 596-605页

作者： Korez, Robert Likar, Bostjan Pernus, Franjo Vrtovec, Tomaz Univ Ljubljana Fac Elect Engn SI-1000 Ljubljana Slovenia

Gradual degeneration of intervertebral discs of the lumbar spine is one of the most common causes of low back pain. Although conservative treatment for low back pain may provide relief to most individuals, surgical intervention may be required for individuals with significant continuing symptoms, which is usually performed by replacing the degenerated intervertebral disc with an artificial implant. For designing implants with good bone contact and continuous force distribution, the morphology of the intervertebral disc space and vertebral body endplates is of considerable importance. In this study, we propose a method for parametric modeling of the intervertebral disc space in three dimensions (3D) and show its application to computed tomography (CT) images of the lumbar spine. The initial 3D model of the intervertebral disc space is generated according to the superquadric approach and therefore represented by a truncated elliptical cone, which is initialized by parameters obtained from 3D models of adjacent vertebral bodies. In an optimization procedure, the 3D model of the intervertebral disc space is incrementally deformed by adding parameters that provide a more detailed morphometric description of the observed shape, and aligned to the observed intervertebral disc space in the 3D image. By applying the proposed method to CT images of 20 lumbar spines, the shape and pose of each of the 100 intervertebral disc spaces were represented by a 3D parametric model. The resulting mean (+/- standard deviation) accuracy of modeling was 1.06 +/- 0.98 mm in terms of radial Euclidean distance against manually defined ground truth points, with the corresponding success rate of 93% (i.e. 93 out of 100 intervertebral disc spaces were modeled successfully). As the resulting 3D models provide a description of the shape of intervertebral disc spaces in a complete parametric form, morphometric analysis was straightforwardly enabled and allowed the computation of the corresponding h

关键词： Intervertebral disc space parametric modeling Superquadrics Three-dimensional (3D) images Computed tomography (CT) Lumbar spine Total disc replacement

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parametric modeling of ultrawideband antennas

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IEEE TRANSACTIONS ON ANTENNAS AND PROPAGATION 2007年第11期55卷 3103-3105页

作者： Duroc, Y. Ghiotto, A. Vuong, T. P. Tedjini, S. LCIS Inst Natl Polytech Grenoble F-26000 Valence France

Compared to narrowband antennas, ultrawideband (UWB) antennas have particular characteristics which involve new ways to model them. This paper introduces the use of parametric modeling to efficiently model transfer functions (and associated impulse responses) of UWB antennas, and to determine an equivalent circuit of their input impedance.

关键词： input impedance parametric modeling transfer function transient response ultrawideband (UWB)

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parametric modeling approach in laser wire additive manufacturing process

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WELDING IN THE WORLD 2023年第4期67卷 885-895页

作者： Mbodj, Natago Guile Abuabiah, Mohammad El Kandaoui, Maxime Yaacoubi, Slah Plapper, Peter Univ Luxembourg Dept Engn 6 Rue Kalergi L-1359 Luxembourg Luxembourg An Najah Natl Univ Dept Mech & Mechatron Engn POB 7 Nablus Palestine Inst Soudure Plateforme DRIEG CND & Assembly 4 Bd Henri Becquerel F-57970 Yutz France

In recent years, the evolution of computer-aided design technology has established a new design method to improve digital model creations. The new design method is called parametric modeling. In this paper, 3D metallic models are printed using a novel parametric modeling approach. The goal of this approach is to use parametric design features to simulate and print 3D metallic objects using Laser Wire Additive Manufacturing (LWAM) process. The proposed approach includes a pattern creation and robot targets assignment while considering several process requirements of LWAM and the robot system. This technique will allow the development of an adaptive robot toolpath for a good deposition process. Finally, a wall, a cylinder, and a complex shape were simulated and deposited to validate the proposed approach. The results show that the approach is feasible, adaptive, and can enhance 3D metallic print in the LWAM process.

关键词： parametric modeling Laser wire additive manufacturing Adaptive toolpath Metallic 3D printing

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parametric modeling and updating for bolted joints of aeroengine casings

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PROCEEDINGS OF THE INSTITUTION OF MECHANICAL ENGINEERS PART C-JOURNAL OF MECHANICAL ENGINEERING SCIENCE 2016年第16期230卷 2940-2951页

作者： Zhai, Xue Fei, Cheng-Wei Wang, Jian-Jun Yao, Xing-Yu Beihang Univ Sch Energy & Power Engn Beijing Peoples R China Hong Kong Polytech Univ Dept Mech Engn Kowloon Hong Kong Peoples R China

To establish accurate finite element (FE) model of bolted joint structures of aeroengine stator system (casings), this work implements the parametric FE modeling and updating of bolted joints of aeroengine stator system with multi-characteristic responses (multi-object). Firstly, the parametric FE modeling approach of bolted joint structure was developed based on the thin layer element method. And then the FE model updating thought of aeroengine stator system was developed based on the probabilistic analysis method. Finally, the parametric modeling and updating of the bolted joints of aeroengine stator system with multi-characteristic responses was completed by the optimization iteration calculation of objective function based on the proposed methods and the static stiffness testing data. Through the parametric modeling of bolted joint structures based on the thin layer method, the complexity of FE model of aeroengine casings with many bolted joint structures is reduced. As shown in the FE model updating of casings with multi-characteristic responses analysis, the static stiffness from the updated model are very close to the test data, in which the maximum relative error decreases to 3.9% from 30.52% and the others are less than 3%, so that the design precision of aeroengine stator system with the many and wide variety of bolted joints gets a great improvement. Moreover, the proposed methods of parametric modeling and model updating for multi-characteristic responses are validated to be effective in the simulation and equivalent of the mechanical characteristics of bolted joints in complex systems like aeroengine stator system.

关键词： Aeroengine casing bolted joint parametric modeling model updating probabilistic design Monte Carlo method

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