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Metamodel-based Global Optimization Using Fuzzy Clustering for Design Space Reduction 被引量:13
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作者 LI Yulin LIU Li +1 位作者 LONG Teng DONG Weili 《Chinese Journal of Mechanical Engineering》 SCIE EI CAS CSCD 2013年第5期928-939,共12页
High fidelity analysis are utilized in modern engineering design optimization problems which involve expensive black-box models.For computation-intensive engineering design problems,efficient global optimization metho... High fidelity analysis are utilized in modern engineering design optimization problems which involve expensive black-box models.For computation-intensive engineering design problems,efficient global optimization methods must be developed to relieve the computational burden.A new metamodel-based global optimization method using fuzzy clustering for design space reduction(MGO-FCR) is presented.The uniformly distributed initial sample points are generated by Latin hypercube design to construct the radial basis function metamodel,whose accuracy is improved with increasing number of sample points gradually.Fuzzy c-mean method and Gath-Geva clustering method are applied to divide the design space into several small interesting cluster spaces for low and high dimensional problems respectively.Modeling efficiency and accuracy are directly related to the design space,so unconcerned spaces are eliminated by the proposed reduction principle and two pseudo reduction algorithms.The reduction principle is developed to determine whether the current design space should be reduced and which space is eliminated.The first pseudo reduction algorithm improves the speed of clustering,while the second pseudo reduction algorithm ensures the design space to be reduced.Through several numerical benchmark functions,comparative studies with adaptive response surface method,approximated unimodal region elimination method and mode-pursuing sampling are carried out.The optimization results reveal that this method captures the real global optimum for all the numerical benchmark functions.And the number of function evaluations show that the efficiency of this method is favorable especially for high dimensional problems.Based on this global design optimization method,a design optimization of a lifting surface in high speed flow is carried out and this method saves about 10 h compared with genetic algorithms.This method possesses favorable performance on efficiency,robustness and capability of global convergence and gives a new optimization strategy for engineering design optimization problems involving expensive black box models. 展开更多
关键词 global optimization metamodel-based optimization reduction of design space fuzzy clustering
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Variable-fidelity optimization with design space reduction 被引量:2
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作者 Mohammad Kashif Zahir Gao Zhenghong 《Chinese Journal of Aeronautics》 SCIE EI CAS CSCD 2013年第4期841-849,共9页
Advanced engineering systems, like aircraft, are defined by tens or even hundreds of design variables. Building an accurate surrogate model for use in such high-dimensional optimization problems is a difficult task ow... Advanced engineering systems, like aircraft, are defined by tens or even hundreds of design variables. Building an accurate surrogate model for use in such high-dimensional optimization problems is a difficult task owing to the curse of dimensionality. This paper presents a new algorithm to reduce the size of a design space to a smaller region of interest allowing a more accurate surrogate model to be generated. The framework requires a set of models of different physical or numerical fidelities. The low-fidelity (LF) model provides physics-based approximation of the high-fidelity (HF) model at a fraction of the computational cost. It is also instrumental in identifying the small region of interest in the design space that encloses the high-fidelity optimum. A surrogate model is then constructed to match the low-fidelity model to the high-fidelity model in the identified region of interest. The optimization process is managed by an update strategy to prevent convergence to false optima. The algorithm is applied on mathematical problems and a two-dimen-sional aerodynamic shape optimization problem in a variable-fidelity context. Results obtained are in excellent agreement with high-fidelity results, even with lower-fidelity flow solvers, while showing up to 39% time savings. 展开更多
关键词 Airfoil optimization Curse of dimensionality Design space reduction Genetic algorithms Kriging Surrogate models Surrogate update strategies Variable fidelity
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A Creation Model from the Gell-Mann Standard Model to the Creation of Bio Cells: Based on the Assumption of Homogeneous 5D Space-Time Universe
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作者 Kai Wai Wong Wan Ki Chow 《Journal of Modern Physics》 2020年第7期1058-1074,共17页
In this paper, we briefly go over the homogeneous 5D model field theory: from the 5D space-time inception, to its quantum field solutions given in terms of Higgs vacuum, filled with magnetic monopole bose fields of al... In this paper, we briefly go over the homogeneous 5D model field theory: from the 5D space-time inception, to its quantum field solutions given in terms of Higgs vacuum, filled with magnetic monopole bose fields of all energies. Then through the space dimension reduction projections, the Gell-Mann standard model was obtained as well as a quantum to Classical connection was made via introducing Bose distribution to the monopoles to obtain the Perelman entropy and Ricci Flow mappings. This provided us a picture to the creation of Astronomical objects, from galaxies to stars and planets. This method of splitting the monopole energy into ranges is extended to show that below the basic rest mass range of the electron and Quark, it still can be applied to explaining for the creation of the chemical elements periodic table. But perhaps the most interesting is in the lowest hundreds of Hz energy range, obtained from yet another 3 fold space symmetry breaking, into 2D × 1D, producing bio nitrogenous bases composed of 3 Carbon 12 in hexagon structures, due to preservation of the 1D monopole standing waves of this low frequencies. From that by imposing gauge changes the monopole states into DNA spectra. Since such spectra states retain the DLRO, it induces formation of charge carriers periodicity in a spherical bio cell.. It was then argued that due to cell’s surface proteins, the structure must contain partial filled VB, with “p” state hole density, and empty CB, separated from VB by a positive band gap. Such band structures resemble known HTC Cuprate ceramics. Since the HTC goes through a Superconductivity transition via the simultaneous bose exciton condensation, providing a Coulomb pressure, which reduces the band gap substantially, and induces the ODLRO transition of the hole density. The same obviously applies to the bio cells. Because of the near continuous exciton levels generated, a matching to the DNA spectra then can always occur by selective choices of proteins on the cell surface. Judging from a numerical study, we did years ago on YBCO, with doping. We found with a large enough VB hole density, the exciton induced superconducting gap can easily lead to <em>T</em><em>c</em> in the room temperature range. In fact by EMF excitation can increase the exciton pressure and trigger the ODLRO transition <em>T</em><em>c</em> upward. In fact, numerical results then suggest there do exist coherent EMF spectra from three key elements: Water, Carbon and Hydrogen, together with Oxygen, as studied over the years by numerous people, starting from Schr<span style="white-space:nowrap;">&ouml;</span>dinger to most recently Geesink. 展开更多
关键词 5D Fermat’s Theorem space Dimension reduction Projections Perelman Mappings The Higgs Vacuum: A B.E. Condensed Monopole Bosons Realization of Excitonic Induced Superconducting “p” Valence Band Orbitals in Bio Cells The Final Coherent Building Block EMF Spectra: Water Carbon Hydrogen and Oxygen
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A Summary of the Homogeneous 5D Universe Creation Model: Expressed in the Dirac Second-Order Quantization Representation 被引量:1
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作者 Kai Wai Wong Wan Ki Chow 《Journal of Modern Physics》 2021年第3期123-138,共16页
A summary of the homogeneous 5D universe model is expressed in the Dirac second-order quantized representation for the magnetic monopoles, identified in terms of the Higgs Bosons, and through systematic ordered excita... A summary of the homogeneous 5D universe model is expressed in the Dirac second-order quantized representation for the magnetic monopoles, identified in terms of the Higgs Bosons, and through systematic ordered excitations of the Higgs vacuum obtained the non-homogeneous 4D Lorentz manifolds filled with masses, corresponding to making space dimension reduction projections, and thus realization of Newtonian gravity, followed by the 3D space symmetry breaking into 2D × 1D that produces the Perelmann-entropy and Ricci-Flow mappings, resulting in the realization of Poincare spheres, represented by nucleus such as Carbon 12, all the way to stars, and matter filled discs, such as stars in galaxies and 2D carbon-based molecular structures like nitrogenous bases. Finally, the forming of RNAs and DNAs, then life forms. 展开更多
关键词 Magnetic Monopoles Higgs Bosons space reduction Projections Perelmann Mappings Nitrogenous Bases and Life Forms
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Gravity observation at continental borderlands (Russia, Primorie, Cape Shults)
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作者 Vladimir Yu. Timofeev Eugenii N. Kalish +7 位作者 Dmitriy G. Ardyukov Maksim G. Valitov Anton V. Timofeev Yurii F. Stus Ruslan G. Kulinich Dmitrii A. Nosov Igor S. Sizikov Bernard Ducarme 《Geodesy and Geodynamics》 2017年第3期193-200,共8页
The paper is focused on different kinds of gravity results obtained in Shults Cape Observatory for 2010 -2015. Gravity observation is interpreted together with GPS observation data which was obtained from 2012 to 2015... The paper is focused on different kinds of gravity results obtained in Shults Cape Observatory for 2010 -2015. Gravity observation is interpreted together with GPS observation data which was obtained from 2012 to 2015 at the same station, The station is situated on Gamov peninsular (42.58° N, 131.15° E, Russia) at the coast of Japan Sea, This region constitutes the eastern boundary of Eurasia. This major continental tectonic feature is associated with a seismic activity, high heat flow and anomalous thickness of earth's crust. The goal of the observation was the investigation of gravity variation with time and seismicity situation monitoring. Gravity observation was developed at special basement by absolute gravimeter (GABL type) and by spring gravimeter (SCINREX CG-5and gPhone type). Tidal models were tested by results of observation with spring gravimeters. Reduction task was solved, as the experimental data received from different points of Shults Cape Observatory was used. Applied reduction coefficient is 203.3 12Gal m l, and agrees with theoretical calculation. Next goal was studying structure of earth's crust by means of gravity models. Gravity anomaly varied from 30 mGal to 46 mGal, which also depend on difference reference system, Experimental results were used for testing of the structure of continental boundary, which also depends on the sea bottom flexion. Thickness of elastic layer was estimated from 12 km to 18 km by using different models. 展开更多
关键词 Absolute and relative gravity observation space geodesy reduction task for gravity Structure models Crust
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Assessing cooling energy reduction potentials by retrofitting traditional cavity walls into passively ventilated cavity walls 被引量:3
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作者 Ri Na Zhigang Shen 《Building Simulation》 SCIE EI CSCD 2021年第4期1295-1309,共15页
A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption.Finding low-cost energy retrofit s... A major roadblock in achieving substantial building energy reduction is the low performance of old buildings that account for a significant portion of the building energy consumption.Finding low-cost energy retrofit solutions that do not disrupt occupants’daily life during the retrofitting is the key to successful building energy retrofit initiatives.In this paper,a novel and low-cost exterior wall retrofitting solution is introduced,and its performance in reducing space cooling load was quantitatively evaluated to demonstrate its feasibility and effectiveness.The primary goal of this paper is to provide a quantitative assessment of the cooling-energy savings potential by using the proposed new wall system.The intended retrofitting targets are the large amount of existing cavity-wall buildings located in hot climate regions.The quantification of the before-after heat-flux reduction was conducted through a 3-dimensional steady-state low turbulence computational fluid dynamics(CFD)model,which is validated by benchmarking its prediction against the published experimental case results.The outcomes of the investigation suggest that this simple low-cost solution has great potentials in reducing buildings’summer cooling load in hot climate regions.The applicability of this solution is not limited to retrofitting existing buildings.New energy-efficient building designs can also adopt this solution in their envelope systems. 展开更多
关键词 low-cost energy retrofit building envelope cavity wall stack effect space cooling energy reduction CFD
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中医人类学的研究回眸——人类学学者访谈录之八十八 被引量:3
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作者 蒋辰雪 许小丽 《广西民族大学学报(哲学社会科学版)》 CSSCI 北大核心 2019年第4期45-48,共4页
以英国牛津大学Elisabeth Hsu教授三十余年来从事中医相关的人类学研究经历为线索,探讨了人类学方法对中医研究的意义,介绍了其作为西方中医人类学家的部分研究成果、观点和最新进展,并对中医人类学发展提出了建议和展望。
关键词 中医人类学 感知理论 反还原论 文化空间
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