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COMPLEX FUNDAMENTAL SOLUTIONS FOR SEMI-INFINITEPLANE AND INFINITE PLANE WITH HOLE UNDER VARIOUS BOUNDARY CONDITIONS

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Applied Mathematics and Mechanics(English Edition) 1998年第4期19卷 335-344页

作者：唐寿高曹志远 Dept. of Eng. Mechanics and Technol. Tongji University Shanghai 200092 China

A general method of finding the complex fundamental solutions for semi-infinite plane and infinite plane with hole under various boundary conditions has be established by using Riemann-Schwarz symmetric principle and ... 详细信息

关键词： fundamental solution Riemann-Schwarz symmetric principle superposition principle

A Two-Scale Asymptotic Analysis of a Time-Harmonic Scattering Problem with a Multi Layered Thin Periodic Domain

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Communications in Computational Physics 2009年第9期6卷 758-776页

作者： Mounir Tlemcani Universite des Sciences et de la Technologie d’Oran U.S.T.O-M.BBP 1505 El M’NaouerAlgeria

The scope of this paper is to show how a two-scale asymptotic analysis,based on a superposition principle,allows us to derive high order approximate boundary conditions for a scattering problem of a time-harmonic wave by a thin and tangentially periodic multi-layered *** periods are assumed of the same order of the *** terms like memory effect and variance-covariance ones are observed contrarily to the laminar *** a result,optimal error estimates are obtained.

关键词： Two-scale asymptotic analysis superposition principle tangential periodicity thin layer approximate boundary condition time-harmonic scattering

Analysis on the stability of the single weld pool formed during the triple-electrode high speed CO2 welding

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China Welding 2010年第2期19卷 56-60页

作者：马晓丽华学明吴毅雄 Shanghai Key Laboratory of Materials Laser Processing and Modification Shanghai Jiao Tong University Shanghai 200240.

The pinch instability theory with free surface and wave superposition principle was applied to understanding the critical disturbance wavelength and the theoretical bead width for the single weld pool formed during the triple-electrode high speed CO2 welding. In addition, the reason for higher stability in the single weld pool was analyzed. Then single-, twin-, and triple-electrode overlaying experiments were conducted. It was found that triple-electrode CO2 welding can improve welding efficiency greatly without reducing the weld quality. The results indicated that the oscillation frequcncy of the weld pool increased, oscillation wavelength decreased, and bead width increased with the increase of welding electrodes under the same disturbance circumstances.

关键词： triple-electrode CO2 welding the pinch instability superposition principle critical wavelength

Fault Tolerance and Overmodulation Algorithm for Three Level Neutral Point Clamped Inverters

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Fault Tolerance and Overmodulation Algorithm for Three Level...

Study on characteristics of well-test type curves for composite reservoir with sealing faults

第36届中国控制会议

作者： Ming Zhang Ze Li Yuanbo Guo Xiaohua Zhang School of Electrical Engineering & Automation Harbin Institute of Technology School of Electrical Engineering Dalian University of Technology

ISBN: (纸本)9781538629185

It has been a hot issue and also a difficulty to study the fault tolerance of multilevel *** topology changes to eight-switch three-phase inverter（ESTPI） if one leg of three-level NPC inverter is *** optimal modulation algorithm of ESTPI is proposed in this *** to the loss of one leg,the DC-link voltage utilization of ESTPI is reduced by ***,an overmodulation algorithm based on superposition principle is proposed to improve DC-link voltage utilization,without increasing DC-link *** proposed method is easier to implement compared with conventional overmodulation strategies for less *** proof and experimental results show that the proposed overmodulation algorithm is effective,and the DC-link voltage utilization can be increased maximally by 10.3%.

关键词： Fault tolerance eight-switch three-phase inverter superposition principle overmodulation

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Petroleum 2018年第3期4卷 309-317页

作者： Qiguo Liu Heng Lu Longxin Li Aiting Mu School of Oil&Gas Engineering Southwest Petroleum UniversityChengduSichuanPR China Exploration and Development Research Institute of PetroChina Southwest Oil and Gas Field Company PR China

The pressure response for the composite reservoirs with a sealing fault locating in inner and outer region is different,which neglected by previous researchers,would cause significant errors during well-test *** on seepage theory,a well-test model of two-region radial composite reservoir with infinite outer boundary has been built in this study considering wellbore storage and skin *** solutions for this model and characteristics of the type curves have been analyzed by applying the method of mirror image,Laplace transformation and superposition principle,including a straight fault,a perpendicular fault and parallel faults *** study shows that the dimensionless pressure derivative curves would be obviously different in two cases:the well to fault distance is larger,and smaller than the half length of the inner-region ***,type curves are presented with reasonable parameters to analyze the distance effect on the dynamic pressure *** results in this study are of great significance。

关键词： Composite reservoir Sealing faults Well-test interpretation Dynamic pressure response superposition principle

Strip distortion generator for simulating inlet flow distortion in gas turbine engine ground test facilities

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Propulsion and Power Research 2016年第4期5卷 287-301页

作者： M.Saleem Yusoof M.Sivapragasam M.D.Deshpande Department of Automotive and Aeronautical Engineering Faculty of Engineering and TechnologyM.S.Ramaiah University of Applied SciencesBengaluruKarnataka 560058India

A methodology has been developed to generate a non-uniform/distoited inlet flow field to test a gas turbine engine in ground test *** distorted flow field is generated by positioning radial and circumferential strips of varying widths upstream of the Aerodynamic Interface *** interacting wakes from these strips are used to generate a given target flow *** approximate superposition of these wakes is investigated and used to construct the strip arrangement which is subsequently validated by computing the flow field by solving the Navier-Stokes *** strip geometry designed using the present methodology is able to produce the target Mach number distribution with a root-mean-square error of 5.06%.

关键词： Inlet flow distortion Strip distortion generator Wake interaction superposition principle Total pressure distortion Distortion parameters

Overmodulation Strategy for Four-Switch Three-Phase Inverter Based on Virtual Voltage Vector

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Overmodulation Strategy for Four-Switch Three-Phase Inverter...

Distribution of contact loads in crushed zone between tunnel boring machine disc cutter and rock

第36届中国控制会议

作者： Ze Li Ming Zhang Yuanbo Guo Xiaohua Zhang School of Electrical Engineering Dalian University of Technology School of Electrical Engineering & Automation Harbin Institute of Technology

ISBN: (纸本)9781538629185

The four-switch three-phase inverter（FSTPI） is the fault-tolerant topology of the six-switch three-phase inverter（SSTPI）,and the maximum output voltage is limited in the linear modulation ***,an overmodulation strategy for FSTPI is presented,based on virtual voltage vector and superposition principle,in order to improve the utilization of the DC voltage,enhance the output capacity of the inverter and extend the operation range of induction *** with the traditional overmodulation strategy,the proposed strategy can make the inverter transit smoothly from the linear operation to the six-step operation with simple online computation,which is convenient for digital realization and can possess balanced output ***,the relationship between SVPWM and carrier-based PWM in the overmodulation region for FSTPI is *** simulation results illustrate the validity and effectiveness of the theoretical analysis.

关键词： Virtual voltage vector superposition principle four-switch three-phase inverter modulated functions

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Journal of Central South University 2019年第9期26卷 2393-2403页

作者： SHI Yu-peng XIA Yi-min TAN Qing ZHANG Yi-chao QIAO Shuo State Key Laboratory of High Performance Complex Manufacturing Central South UniversityChangsha 410083China College of Mechanical and Electrical Engineering Central South UniversityChangsha 410083China Patent Examination Cooperation Sichuan Center of the Patent Office SIPOChengdu 610000China

The construction efficiency and quality of tunnel boring machines(TBMs)is largely determined by the service life of cutting tools,which is the result of contact loads in the crushed zone between cutter ring and *** this paper,a series of rock breaking tests were conducted with a 216 mm diameter disc cutter and concrete *** on the superposition principle,the distribution of contact loads between disc cutter and rock were obtained by using the truncated singular value decomposition(TSVD).The results show that both the peak value and the whole numerical distribution of the radial strains on the cutter ring increase with the increase of the *** distribution curves of the contact loads show an approximate parabola going downwards,which indicates contact loads are more *** front non-loading area with a ratio from 1.8%to 5.4%shows an increasing trend with the increase of ***,the change of rear non-loading area is not *** is believed that the conclusions have guidance for the study of rock breaking mechanism and manufacturing process of the disc cutter.

关键词： disc cutter contact loads superposition principle non-loading area

EIT Image Reconstruction by Modified Data

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Journal of Biomedical Science and Engineering 2016年第10期9卷 99-106页

作者： B. Gong B. Schullcke S. Krueger-Ziolek K. Moeller Institute of Technical Medicine Furtwangen University Villingen-Schwenningen Germany

Electrical impedance tomography (EIT) is a radiation-free imaging method. Canoni-cally, in lung EIT, 16 electrodes are placed horizontally on the thorax skin. By inject-ing currents through electrodes attached to the skin, a set of induced voltage measure-ments can be collected. The conductivity distribution on the chest plane can be ob-tained from these electrical boundary conditions. It has been reported that the adjacent current injection pattern is sub-optimal for EIT reconstruction. However, this adjacent current injection pattern is commonly used in commercially available EIT devices. In this study, we modify the boundary conditions according to the superposition principle of the electrical field. As a result, boundary conditions of the adjacent current pattern will be transformed to those corresponding to “skip-3” current injection pattern. Simulation results indicated that reconstruction benefits from the modified boundary conditions.

关键词： Electrical Impedance Tomography Current Pattern superposition principle