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Non-uniform Doo-Sabin Subdivision Surface via Eigen Polygon

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Journal of Systems Science & Complexity 2021年第1期34卷 3-20页

作者： ALAM Md Nur LI Xin School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026China

This paper constructs a new Non-uniform Doo-Sabin subdivision scheme via eigen polygon.The authors proved that the limit surface is always convergent and is G1 continuous for any valence and any positive knot intervals under a minor assumption, that λ is the second and third eigenvalues of the subdivision matrix. And then, a million of numerical experiments are tested with randomly selecting positive knot intervals, which verify that our new subdivision scheme satisfies the assumption.However this is not true for the other two existing Non-uniform Doo-Sabin schemes in Sederberg, et al.(1998), Huang and Wang(2013). In additional, numerical experiments indicate that the quality of the new limit surface can be improved.

关键词： Doo-Sabin Non-uniform splines subdivision

Single-Layer Wideband Circularly Polarized Antenna Using Non-uniform Metasurface for C-band Applications

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Computers, Materials & Continua 2021年第8期68卷 2487-2498页

作者： Huy Hung Tran Khoa Nguyen-Dang Niamat Hussain Faculty of Electrical and Electronic Engineering PHENIKAA UniversityHanoi12116Vietnam PHENIKAA Research and Technology Institute(PRATI) A&A Green Phoenix Group JSCCau Giay11313HanoiVietnam Department of Computer and Communication Engineering Chungbuk National UniversityCheongju 28644Korea

A single-layer design of Non-uniform metasurface(MS)based circularly polarized(CP)antenna with wideband operation characteristic is proposed and investigated in this paper.The antenna is excited by a truncated corner squared patch as a primary radiating CP source.Then,a Non-uniform MS is placed in the same layer with the driven patch.Besides increasing the impedance bandwidth,the Non-uniform MS also generates two additional CP bands in the high frequency band,leading to significantly increase the antenna’s overall performances.The use of Non-uniform MS distinguishes our design from the other CP MS based antennas in literature,in which the MS is formed by multiple uniform unit cells and placed in different layer with the radiating element.For validation,an antenna prototype,whose overall dimensions of 0.94λ_(o)×0.94λ_(o)×0.06λ_(o) at the center operating frequency,is fabricated and experimentally tested.The measured operating bandwidth with|S11|≤−10 dB and AR≤3 dB is 27.1%(5.1–6.7 GHz)and the broadside gain within this band is from 5.7 to 7.2 dBic.Compared to the other related works,the proposed antenna has advantage of very wideband operation with single-layer design.

关键词： Circular polarization metasurface Non-uniform patch antenna wideband

A novel unified model predicting flow stress and grain size evolutions during hot working of Non-uniform as-cast 42CrMo billets

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Chinese Journal of Aeronautics 2019年第2期32卷 531-545页

作者： Lianggang GUO Fengqi WANG Pengliang ZHEN Xuechao LI Mei ZHAN School of Materials Science and Engineering Northwestern Polytechnical University

The cast preformed forming process(CPFP) is increasingly considered and applied in the metal forming industries due to its short process, low cost, and environmental friendliness, especially in the aerospace field. However, how to establish a unified model of a Non-uniform as-cast billet depicting the flow stress and microstructure evolution behaviors during hot working is the key to microstructure prediction and parameter optimization of the CPFP. In this work, hot compression tests are performed using a Non-uniform as-cast 42 CrMo billet at 1123–1423 K and 0.01–1sà1. The effect laws of the Non-uniform state of the as-cast billet with different initial grain sizes on the flow stress and microstructure are revealed deeply. Based on experimental results, a unified model of flow stress and grain size evolutions is developed by the internal variable modeling method. Verified results show that the model can well describe the responses of the flow stress and microstructure to deformation conditions and initial grain sizes. To further evaluate its reliability, the unified model is applied to FE simulation of the cast preformed ring rolling process.The predictions of the rolling force and grain size indicate that it could well describe the flow stress and microstructure evolutions during the process.

关键词： Cast preformed forming process Flow stress Grain size Non-uniform as-cast 42CrMo billet Ring rolling Unified model

On the Complex Difference Equation of Hypergeometric Type on Non-uniform Lattices

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Acta Mathematica Sinica,English Series 2020年第5期36卷 487-511页

作者： Jin Fa CHENG School of Mathematical Sciences Xiamen UniversityXiamen 361005P.R.China

In this article,we obtain a new fundamental theorems for Nikiforov-Uvarov-Suslov complex difference equation of hypergeometric type by the method of Euler integral transformation,its expression is different from Suslov’s Theorem.We also establish the adjoint equation for Nikiforov-Uvarov-Suslov difference equation of hypergeometric type on Non-uniform lattices,and prove it to be a difference equation of hypergeometric type on Non-uniform lattices as well.The particular solutions of the adjoint equation are then obtained.As an appliction of these particular solutions,we use them to obtain the particular solutions for the original difference equation of hypergeometric type on Non-uniform lattices and other important results.

关键词： Special function orthogonal polynomials adjoint equation difference equation of hypergeometric type Non-uniform lattice

Experimental Study on Occupant's Thermal Responses under the Non-uniform Conditions in Vehicle Cabin during the Heating Period

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Chinese Journal of Mechanical Engineering 2014年第2期27卷 331-339页

作者： ZHANG Wencan CHEN Jiqing LAN Fengchong School of Mechanical & Automotive Engineering South China University of Technology School of Mechanical & Electrical Engineering Foshan University Key Laboratory of Guangdong Province of Automotive Engineering South China University of Technology

The existing investigations on thermal comfort mostly focus on the thermal environment conditions, especially of the air-flow field and the temperature distributions in vehicle cabin. Less attention appears to direct to the thermal comfort or thermal sensation of occupants, even to the relationship between thermal conditions and thermal sensation. In this paper, a series of experiments were designed and conducted for understanding the Non-uniform conditions and the occupant＇s thermal responses in vehicle cabin during the heating period. To accurately assess the transient temperature distribution in cabin in common daily condition, the air temperature at a number of positions is measured in a full size vehicle cabin under natural winter environment in South China by using a discrete thermocouples network. The occupant body is divided into nine segments, the skin temperature at each segment and the occupant＇s local thermal sensation at the head, body, upper limb and lower limb are monitored continuously. The skin temperature is observed by using a discrete thermocouples network, and the local thermal sensation is evaluated by using a seven-point thermal comfort survey questionnaire proposed by American Society of Heating, Refrigerating and Air-Conditioning Engineers, Inc（ASHRAE） Standard. The relationship between the skin temperature and the thermal sensation is discussed and regressed by statistics method. The results show that the interior air temperature is highly Non-uniform over the vehicle cabin. The locations where the occupants sit have a significant effect on the occupant＇s thermal responses, including the skin temperature and the thermal sensation. The skin temperaWa-e and thermal sensation are quite different between body segments due to the effect of Non-uniform conditions, clothing resistance, and the human thermal regulating system. A quantitative relationship between the thermal sensation and the skin temperature at each body segment of occupant in real life traffic is presented. The investigation re

关键词： vehicle cabin thermal environment thermal comfort skin temperature Non-uniform

Investigation and modeling of the avalanche effect in MOSFETs with Non-uniform finger spacing

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Journal of Semiconductors 2011年第12期32卷 64-67页

作者：刘军孙玲玲 Marissa Condon Key Laboratory of RF Circuits and Systems Ministry of EducationHangzhou Dianzi University School of Electronic Engineering Dublin City University

This paper investigates the effect of a Non-uniform gate-finger spacing layout structure on the avalanche breakdown performance of RF CMOS technology. Compared with a standard multi-finger device with uniform gate-finger spacing, a device with Non-uniform gate-finger spacing represents an improvement of 8.5% for the drain-source breakdown voltage （BVds） and of 20% for the thermally-related drain conductance. A novel compact model is proposed to accurately predict the variation of BVds with the total area of devices, which is dependent on the different finger spacing sizes. The model is verified and validated by the excellent match between the measured and simulated avalanche breakdown characteristics for a set of uniform and Non-uniform gate-finger spacing arranged nMOSFETs.

关键词： Non-uniform gate-finger spacing avalanche breakdown RF CMOS

Explicit Gaussian Quadrature Rules for C1 Cubic Splines with Non-uniform Knot Sequences

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Communications in Mathematics and Statistics 2021年第3期9卷 331-345页

作者： Peng Chen Xin Li School of Mathematical Sciences University of Science and Technology of ChinaHefei 230026People’s Republic of China

This paper provides the explicit and optimal quadrature rules for the cubic C1 spline space,which is the extension of the results in Ait-Haddou et al.(J Comput Appl Math 290:543–552,2015)for less restricted Non-uniform knot values.The rules are optimal in the sense that there exist no other quadrature rules with fewer quadrature points to exactly integrate the functions in the given spline space.The explicit means that the quadrature nodes and weights are derived via an explicit recursive formula.Numerical experiments and the error estimations of the quadrature rules are also presented in the end.

关键词： Gaussian quadrature Non-uniform Isogeometric analysis Cubic splines

High efficiency X-band relativistic backward wave oscillator with Non-uniform slow wave structures

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Chinese Physics C 2012年第8期36卷 750-752页

作者：吴洋许州李正红马乔生唐传祥 Department of Engineering Physics Tsinghua University Institute of Applied Electronics China Academy of Engineering Physics Science and Technology on High Power Microwave Laboratory

Backward wave oscillators （BWOs） driven by intense relativistic electron beams are very efficient means of producing high-power microwaves. However, the efficiency of conventional BWO is lower than 30%. An X-band oversized BWO with Non-uniform slow wave structure is designed to improve RF output characteristics. In particle-in-cell simulation, a high power microwave with a power of 8.0 GW and efficiency of 40% is obtained, compared with that of 30% obtained in a conventional relativistic BWO.

关键词： high power microwave BWO slow wave structure Non-uniform

Analysis of Non-uniform hetero-gate-dielectric dual-material control gate TFET for suppressing ambipolar nature and improving radio-frequency performance

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Chinese Physics B 2019年第10期28卷 571-578页

作者：许会芳崔健孙雯韩新风 Institute of Electrical and Electronic Engineering Anhui Science and Technology University

A tunnel field-effect transistor(TFET) is proposed by combining various advantages together, such as Non-uniform gate-oxide layer, hetero-gate-dielectric(HGD), and dual-material control-gate(DMCG) technology. The effects of the length of Non-uniform gate-oxide layer and dual-material control-gate on the on-state, off-state, and ambipolar currents are investigated. In addition, radio-frequency performance is studied in terms of gain bandwidth product, cut-off frequency,transit time, and transconductance frequency product. Moreover, the length of Non-uniform gate-oxide layer and dualmaterial control-gate are optimized to improve the on-off current ratio and radio-frequency performances as well as the suppression of ambipolar current. All results demonstrate that the proposed device not only suppresses ambipolar current but also improves radio-frequency performance compared with the conventional DMCG TFET, which makes the proposed device a better application prospect in the advanced integrated circuits.

关键词： Non-uniform gate-oxide layer ambipolar current radio-frequency performances tunnel fieldeffect transistor