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Estimates of Approximation Numbers and Applications

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Acta Mathematica Sinica,English Series 2012年第9期28卷 1883-1896页

作者： Veli SHAKHMUROV department of electronics Engineering and Communication Okan University

In this study, the estimates of approximation numbers of embedding operators in weighted spaces have been analyzed. These estimates depend on orders of differential operators, dimensions of function spaces and weighted functions. This fact implies that the associated embedding operators belong to Schatten class of compact operators. By using these estimates, the discreetness of spectrum and completion of root elements relating to principal nonselfedjoint degenerate differential operators is obtained.

关键词： Approximation numbers Kolmogorov numbers separable boundary value problems differential-operator equations Banach-valued function spaces operator-vMued multipliers interpo- lation of Banach spaces

Polar Mixing Optical Phonon Spectra in Wurtzite GaN Cylindrical Quantum Dots: Quantum Size and Dielectric Effects

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Communications in Theoretical Physics 2010年第5期53卷 963-970页

作者：张立廖建尚 department of Mechanism and electronics Guangzhou Panyu Polytechnic

The interface-optical-propagating （IO-PR） mixing phonon modes of a quasi-zero-dimensional （QOD） wurtzite cylindrical quantum dot （QD） structure are derived and studied by employing the macroscopic dielectric continuum model. The analytical phonon states of IO-PR mixing modes are given. It is found that there are two types of IO-PR mixing phonon modes, i.e. p-IO//z-PR mixing modes and the z-IO//p-PR mixing modes existing in QOD wurtzite QDs. And each IO-PR mixing modes also have symmetrical and antisymmetrieal forms. Via a standard procedure of field quantization, the Frohlich Hamiltonians of electron-（IO-PR） mixing phonons interaction are obtained. Numerical calculations on a wurtzite GaN cylindrical QD are performed. The results reveal that both the radial-direction size and the axial-direction size as well as the dielectric matrix have great influence on the dispersive frequencies of the IO-PR mixing phonon modes. The limiting features of dispersive curves of these phonon modes are discussed in depth. The phonon modes ＂reducing＂ behavior of wurtzite quantum confined systems has been observed obviously in the structures. Moreover, the degenerating behaviors of the IO-PR mixing phonon modes in wurtzite QOD QDs to the IO modes and PR modes in wurtzite Q2D QW and QID QWR systems are analyzed deeply from both of the viewpoints of physics and mathematics.

关键词： wurtzite nitride quantum dots phonon spectra electron-phonon interactions quantum size and dielectric effect

Free Boundary Value Problems for Abstract Elliptic Equations and Applications

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Chinese Annals of Mathematics,Series B 2011年第5期32卷 749-770页

作者： Veli SHAKHMUROV department of electronics Engineering and Communication Okan University

The free boundary value problems for elliptic differential-operator equations are *** conditions for the uniform maximal regularity with respect to boundary parameters and the Fredholmness in abstract L p-spaces are *** application,the nonlocal free boundary problems for finite or infinite systems of elliptic and anisotropic type equations are studied.

关键词： Free boundary value problems Sobolev-Lions type spaces Differential-operator equations Maximal Lp regularity Banach spaces Operator-

ABSTRACT CAPACITY OF REGIONS AND COMPACT EMBEDDING WITH APPLICATIONS

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Acta Mathematica Scientia 2011年第1期31卷 49-67页

作者： Veli Shakhmurov department of electronics Engineering and Communication Okan University

The weighted Sobolev-Lions type spaces W pl,γ（Ω; E0, E） = W pl,γ（Ω; E） ∩ Lp,γ （Ω; E0） are studied, where E0, E are two Banach spaces and E0 is continuously and densely embedded on E. A new concept of capacity of region Ω ∈ Rn in W pl,γ（; E0, E） is introduced. Several conditions in terms of capacity of region Ω and interpolations of E0 and E are found such that ensure the continuity and compactness of embedding operators. In particular, the most regular class of interpolation spaces Eα between E0 and E, depending of α and l, are found such that mixed differential operators Dα are bounded and compact from W pl,γ（Ω; E0, E） to Eα-valued Lp,γ spaces. In applications, the maximal regularity for differential-operator equations with parameters are studied.

关键词： Capacity of regions embedding theorems Banach-valued function spaces differential-operator equations Semigroups of operators operator-valued Fourier multipliers interpolation of Banach spaces

Power Reallocation and Complexity Enhancement for Beyond 4G Systems

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China Communications 2019年第6期16卷 114-128页

作者： Omar Daoud Communications and electronics Engineering department Philadelphia University

Competitiveness in the modern wireless systems’provided services is a key factor in the development,in addition to the adaptation to/harmonization of user ***,this paper discussed the quality of services from the point of view of the need for supporting the needed data *** this purpose,a benchmark based on Multi-Antenna Multiband Orthogonal Frequency Division Multiplexing has been proposed to compatible with Ultra-Wideband systems such as the fifth generation based *** order to enhance the system quality of service,the structure of the ultra-wideband system’s main stage;namely Orthogonal Frequency Division Multiplexing has been modified by imposing a low complexity designed Haar-wavelets stage instead of the fast Fourier transform *** is in addition to reallocate the transmitted power in order to reduce the effect of one of the main drawbacks that is found in the Orthogonal Frequency Division Multiplexing;namely the peak-to-average power ratio problem.A MATLAB simulation has been performed in order to validate the propositions that have been made based on six different performance *** a result,the new propositions were achieved our targets by reducing the system’s complexity in terms of mathematical operations and by giving promising results in managing the transmitted ***,the effectiveness of such work has been verified and compared with four different work in the literature。

关键词： multi antennas-multiband wireless PAPR Haar-DWT power reallocation ACLR EVM

A novel NN based rotor flux MRAS to overcome low speed problems for rotor resistance estimation in vector controlled IM drives

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Frontiers in Energy 2016年第4期10卷 382-392页

作者： Venkadesan ARUNACHALAM Himavathi SRINWASAN A. MUTHURAMALINGAM department of Electrical and electronics Engineering National Instituteof Technology Puducherry Karaikal 609605 India department of Electrical and electronics Engineering PondicherryEngineering College Puducherry 605014 India

This paper presents a new neural network based model reference adaptive system （MRAS） to solve low speed problems for estimating rotor resistance in vector control of induction motor （IM）. The MRAS using rotor flux as the state variable with a two layer online trained neural network rotor flux estimator as the adaptive model （FLUX-MRAS） for rotor resistance estimation is popularly used in vector control. In this scheme, the reference model used is the flux estimator using voltage model equations. The voltage model encounters major drawbacks at low speeds, namely, integrator drift and stator resistance variation problems. These lead to a significant error in the estimation of rotor resistance at low speed. To address these problems, an ofltine trained NN with data incorporating stator resistance variation is proposed to estimate flux, and used instead of the voltage model. The ofttine trained NN, modeled using the cascade neural network, is used as a reference model instead of the voltage model to form a new scheme named as ＂NN-FLUX- MRAS.＂ The NN-FLUX-MRAS uses two neural net- works, namely, otttine trained NN as the reference model and online trained NN as the adaptive model. The performance of the novel NN-FLUX-MRAS is compared with the FLUX-MRAS for low speed problems in terms of integral square error 0SE）, integral time square error （ITSE）, integral absolute error （IAE） and integral time absolute error （ITAE）. The proposed NN-FLUX-MRAS is shown to overcome the low speed problems in Matlab simulation.

关键词： rotor resistance stator resistance low speed Error analysis Pest Control ITAE Instant messaging Vector control MRAS gene rotor flux State variable reference model

Effect of electric field on metallic SWCNT interconnects for nanoscale technologies

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Journal of Semiconductors 2015年第3期36卷 92-98页

作者： Harsimran Kaur Karamjit Singh Sandha department of electronics and Communication Engineering Thapar University

The influence of an electric field on metallic single walled carbon nanotube （SWCNT） interconnects is studied. A voltage-dependent equivalent circuit model is presented for the impedance parameters of single-wall carbon nanotubes that capture various electron-phonon scattering mechanisms as a function of the electric field. To estimate the performance of SWCNT bundle interconnects, signal delay and power dissipation are calculated based on the field dependent model that results in an improvement in the delay and power estimation accuracy compared to the field-independent model. We find that the power delay product of a SWCNT bundle increases with the increase in electric field but decreases with technology scaling showing that at a low electric field, the SWCNT bundle is a potential reliable alternative interconnect for future high performance VLSI industry at scaled technologies.

关键词： carbon nanotube single wall carbon nanotube metallic single wall carbon nanotube multiwall carbon nanotube very large scale integration

A smooth co-ordination control for a hybrid autonomous power system （HAPS） with battery energy storage （BES）

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Frontiers in Energy 2015年第1期9卷 31-42页

作者： C. K. ARAVINDI C. NAGAMANI G. SARAVANA ILANGO department of Electrical and electronics Engineering National Instituteof Technology Tiruchirappalli 620015 India department of Electrical and electronics Engineering National Instituteof Technology Trichy 620015 India

The standalone hybrid power system constitu- tes a synchronous generator driven by a diesel engine, renewable energy source （wind） apart from a battery energy storage system. A coherent control strategy to regulate the voltage and frequency of the standalone grid is proposed in this paper. The system is simulated using Matlab/Simulink for preliminary validation and further tested on a laboratory prototype which involves a TMS320LF2407A DSP controller to digitally implement the control strategy. The dynamic behavior of the system is perused through the direct connection of an induction machine. The control strategy is verified for step changes in load and variation in wind power.

关键词： standalone hybrid power system batteryenergy storage system (BESS) power conversion

Photovoltaic-based DC microgrid with partial shading and fault tolerance

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Journal of Modern Power Systems and Clean Energy 2019年第2期7卷 340-349页

作者： Carlos CORREA-BETANZO Hugo CALLEJA Carlos AGUILAR Adolfo R.LOPEZ-NUNEZ Elías RODRIGUEZ electronics department National Center for Research and Development of Technology62490 CuernavacaMorelosMexico electronics department Technological Institute of Celaya38010 CelayaGuanajuatoMexico

Partial shading is a common problem that affects bus regulation in DC microgrids with several photovoltaic(PV) modules as energy sources, as a result of reduced solar irradiance reaching the *** problem can be mitigated by incorporating batteries, but if they are not included, appropriate control strategies must be used. This paper presents a new approach in a PV-based DC microgrid, which provides a high-quality bus voltage regulation in islanding mode, without being affected by partial shading or problems associated with PV module connection and disconnection. The solution proposed herein ensures a proper voltage regulation without being affected by problems such as failures in PV modules or mismatch between them. Besides, it can help to prevent PV partial shade stress by disconnecting the affected modules. A further advantage of the approach is the flexibility to connect more PV modules. The advantages of this approach were verified in a 200 W prototype.

关键词： Photovoltaic Microgrid Partial shading Fault Control strategy