检索结果-内蒙古大学图书馆

Wearable Electronics: Metal/Polymer Based Stretchable Antenna for Constant Frequency Far‐Field Communication in Wearable Electronics (Adv. Funct. Mater. 42/2015)

引用

Advanced Functional Materials 2015年第42期25卷

作者： Aftab M. Hussain Farhan A. Ghaffar Sung I. Park John A. Rogers Atif Shamim Muhammad M. Hussain Integrated Nanotechnology Lab CEMSE Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955‐6900 Saudi Arabia IMAPCT Lab CEMSE Division King Abdullah University of Science and Technology (KAUST) Thuwal 23955‐6900 Saudi Arabia Department of Materials Science and Engineering Chemistry Mechanical Science and Engineering Electrical and Computer Engineering Beckman Institute for Advanced Science and Technology and Frederick Seitz Materials Research Laboratory University of Illinois at Urbana–Champaign Urbana IL 61801 USA

来源：评论

学校读者我要写书评

暂无评论

Load-aware modeling for uplink cellular networks in a multi-channel environment

Load-aware modeling for uplink cellular networks in a multi-...

引用

IEEE International Symposium on Personal, Indoor and Mobile Radio Communications (PIMRC)

作者： Ahmad AlAmmouri Hesham ElSawy Mohamed-Slim Alouini Computer Electrical and Mathematical Sciences and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Makkah Province Saudi Arabia

ISBN: (纸本)9781479949113

We exploit tools from stochastic geometry to develop a tractable analytical approach for modeling uplink cellular networks. The developed model is load aware and accounts for per-user power control as well as the limited transmit power constraint for the users' equipment (UEs). The proposed analytical paradigm is based on a simple per-user power control scheme in which each user inverts his path-loss such that the signal is received at his serving base station (BS) with a certain power threshold ρ Due to the limited transmit power of the UEs, users that cannot invert their path-loss to their serving BSs are allowed to transmit with their maximum transmit power. We show that the proposed power control scheme not only provides a balanced cell center and cell edge user performance, it also facilitates the analysis when compared to the state-of-the-art approaches in the literature. To this end, we discuss how to manipulate the design variable ρ in response to the network parameters to optimize one or more of the performance metrics such as the outage probability, the network capacity, and the energy efficiency.

关键词： Interference Power control Uplink Signal to noise ratio Load modeling Analytical models Stochastic processes

来源：评论

学校读者我要写书评

暂无评论

On the performance of free-space optical wireless communication systems over double generalized gamma fading channels

On the performance of free-space optical wireless communicat...

引用

International Conference on Communications and Networking, ComNet

作者： Hessa AlQuwaiee Imran Shafique Ansari Mohamed-Slim Alouini Computer Electrical and Mathematical Sciences and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Makkah Province Kingdom of Saudi Arabia

Starting with the double generalized Gamma (GG) model that was proposed in [1] to describe turbulence-induced fading in free-space optical (FSO) systems, we propose a new unified model which accounts for the impact of pointing errors and type of receiver detector. Based on this new unified model, we study the performance of FSO links operating over these kind of channels. All our analytical results are verified using computer based Monte-Carlo simulations.

关键词： Fading Signal to noise ratio Atmospheric modeling Bit error rate Adaptive optics Optical mixing Optical receivers

来源：评论

学校读者我要写书评

暂无评论

A Broadband Metasurface-Based Terahertz Flat-Lens Array

引用

Advanced Optical Materials 2015年第6期3卷 779-785页

作者： Wang, Qiu Zhang, Xueqian Xu, Yuehong Tian, Zhen Gu, Jianqiang Yue, Weisheng Zhang, Shuang Han, Jiaguang Zhang, Weili Center for Terahertz Waves and College of Precision Instrument and Optoelectronics Engineering Tianjin Univ. and the Key Lab. of Optoelectronics Inf. and Technol. Tianjin (Ministry of Education) Tianjin 300072 China Advanced Nanofabrication and Imaging Core Lab King Abdullah University of Science and Technology (KAUST) Thuwal 23955-6900 Saudi Arabia School of Physics and Astronomy University of Birmingham Birmingham B15 2TT United Kingdom School of Electrical and Computer Engineering Oklahoma State University Stillwater 74078 OK United States

来源：评论

学校读者我要写书评

暂无评论

Analysis of electromagnetic wave interactions on nonlinear scatterers using time domain volume integral equations

Analysis of electromagnetic wave interactions on nonlinear s...

引用

USNC-URSI Radio science Meeting (Joint with AP-S Symposium)

作者： Hüseyin Arda Ülkü Sadeed Bin Sayed Hakan Bagci Division of Computer Electrical and Mathematical Sciences and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal KSA Department of Electronics Engineering Gebze Institute of Technology Kocaeli Turkey

Effects of material nonlinearities on electromagnetic field interactions become dominant as field amplitudes increase. A typical example is observed in plasmonics, where highly localized fields “activate” Kerr nonlinearities. Naturally, time domain solvers are the method of choice when it comes simulating these nonlinear effects. Oftentimes, finite difference time domain (FDTD) method is used for this purpose. This is simply due to the fact that explicitness of the FDTD renders the implementation easier and the material nonlinearity can be easily accounted for using an auxiliary differential equation (J.H. Green and A. Taflove, Opt. Express, 14(18), 8305-8310, 2006). On the other hand, explicit marching on-in-time (MOT)-based time domain integral equation (TDIE) solvers have never been used for the same purpose even though they offer several advantages over FDTD (E. Michielssen, et al., ECCOMAS CFD, The Netherlands, Sep. 5-8, 2006). This is because explicit MOT solvers have never been stabilized until not so long ago. Recently an explicit but stable MOT scheme has been proposed for solving the time domain surface magnetic field integral equation (H.A. Ulku, et al., IEEE Trans. Antennas Propag., 61(8), 4120-4131, 2013) and later it has been extended for the time domain volume electric field integral equation (TDVEFIE) (S. B. Sayed, et al., Pr. Electromagn. Res. S., 378, Stockholm, 2013). This explicit MOT scheme uses predictor-corrector updates together with successive over relaxation during time marching to stabilize the solution even when time step is as large as in the implicit counterpart. In this work, an explicit MOT-TDVEFIE solver is proposed for analyzing electromagnetic wave interactions on scatterers exhibiting Kerr nonlinearity. Nonlinearity is accounted for using the constitutive relation between the electric field intensity and flux density. Then, this relation and the TDVEFIE are discretized together by expanding the intensity and flux using half and fu

关键词： Time-domain analysis Integral equations Finite difference methods Electromagnetic scattering Materials Electric fields computers

来源：评论

学校读者我要写书评

暂无评论

Analysis of transient plasmonic interactions using an MOT-PMCHWT integral equation solver

Analysis of transient plasmonic interactions using an MOT-PM...

引用

USNC-URSI Radio science Meeting (Joint with AP-S Symposium)

作者： Ismail Enes Uysal Hüseyin Arda Ülkü Hakan Bağcı Division of Computer Electrical and Mathematical Sciences and Engineering King Abdullah University of Science and Technology Thuwal Saudi Arabia Department of Electronics Engineering Gebze Institute of Technology Kocaeli Turkey

In this work, a marching on-in-time (MOT) scheme is proposed to solve the Poggio-Miller-Chan-Harrington-Wu-Tsai (PMCHWT) (L. N. MedgyesiMitschang et al., J. Opt. Soc. Am. A, 11(4), 1383-1398, 1994) IE for analyzing transient plasmonic interactions. The MOT-PMCHWT solver calls for convolutions of the spatio-temporal basis functions with the time domain Green function of the dispersive medium. These convolutions are carried out using a semi-numerical procedure. It is shown that Green function consists of a Dirac delta term and a temporal tail. The convolution with the delta term is analytically evaluated. Samples of the temporal tail are computed from frequency domain samples using the Fast Relaxed Vector Fitting (FRVF) algorithm (B. Gustavsen, IEEE Trans. Power Delivery, 21(3), 1587-1592, 2006). FRVF generates a rational function fit to frequency domain samples, which is used in time domain to represent the tail of the Green function in terms of shifted exponentials. Applying this procedure to every source-observer pair during the computation of MOT matrix entries is computationally costly. Therefore, a look-up table consisting of Green function samples at discrete distances and times is generated. Then, an interpolation scheme is used to fill the MOT matrix elements.

关键词： Time-domain analysis Green's function methods Plasmons Mathematical model Transient analysis Integral equations Metals

来源：评论

学校读者我要写书评

暂无评论

An explicit marching on-in-time solver for the time domain volume magnetic field integral equation

An explicit marching on-in-time solver for the time domain v...

引用

USNC-URSI Radio science Meeting (Joint with AP-S Symposium)

作者： Sadeed Bin Sayed Hüseyin Arda Ülkü Hakan Bagci Division of Computer Electrical and Mathematical Sciences and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal KSA Department of Electronics Engineering Gebze Institute of Technology Kocaeli Turkey

Summary form only given. Transient scattering from inhomogeneous dielectric objects can be modeled using time domain volume integral equations (TDVIEs). TDVIEs are oftentimes solved using marching on-in-time (MOT) techniques. Classical MOT-TDVIE solvers expand the field induced on the scatterer using local spatio-temporal basis functions. Inserting this expansion into the TDVIE and testing the resulting equation in space and time yields a system of equations that is solved by time marching. Depending on the type of the basis and testing functions and the time step, the time marching scheme can be implicit (N. T. Gres, et al., Radio Sci., 36(3), 379-386, 2001) or explicit (A. Al-Jarro, et al., IEEE Trans. Antennas Propag., 60(11), 5203-5214, 2012). Implicit MOT schemes are known to be more stable and accurate. However, under low-frequency excitation, i.e., when the time step size is large, they call for inversion of a full matrix system at very time *** can expect that an explicit scheme would be more efficient at low frequencies if it uses the same time step as its implicit counterpart while maintaining its stability and accuracy. Indeed, recently a novel explicit MOT solver, which satisfies this criterion, has been developed for solving the time domain surface magnetic field integral equation (H. A. Ulku, et al., IEEE Trans. Antennas Propag., 61(8), 4120-4131, 2013). In this work, this explicit MOT scheme is applied in solving the time domain volume magnetic field integral equation (TDVMFIE). The proposed solver expands the unknown fields using curl-conforming basis functions in space. Inserting this expansion into the TDVMFIE and using Galerkin testing yield a semi-discrete system of equations. This system is integrated in time using a predictor-corrector scheme (A. Glaser and V. Rokhlin, J. Sci. Comput., 38(3), 368-399, 2009) to obtain the coefficients of the expansion. The resulting scheme calls for inversion of a matrix system at every time step but this c

关键词： Time-domain analysis Integral equations Numerical stability Stability criteria Thermal stability Magnetic fields Mathematical model

来源：评论

学校读者我要写书评

暂无评论

On the maximum and minimum of two modified Gamma-Gamma variates with applications

On the maximum and minimum of two modified Gamma-Gamma varia...

引用

IEEE Conference on Wireless Communications and Networking

In this work, we derive the statistical characteristics of the maximum and the minimum of two modified 1 Gamma-Gamma variates in closed-form in terms of Meijer's G-function and the extended generalized bivariate Meijer's G-function. Then, we rely on these new results to present the performance analysis of (i) a dual-branch free-space optical selection combining diversity undergoing independent but not necessarily identically distributed Gamma-Gamma fading under the impact of pointing errors and of (ii) a dual-hop free-space optical relay transmission system. computer-based Monte-Carlo simulations verify our new analytical results.

关键词： Radio frequency Signal to noise ratio Bit error rate Relays Diversity reception Optical transmitters

来源：评论

学校读者我要写书评

暂无评论

On the symbol error rate of M-ary MPSK over generalized fading channels with additive Laplacian noise

On the symbol error rate of M-ary MPSK over generalized fadi...

引用

IEEE International Symposium on Information Theory

作者： Hamza Soury Mohamed-Slim Alouini Computer Electrical and Mathematical Sciences and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Makkah Province Kingdom of Saudi Arabia

This paper considers the symbol error rate of M-ary phase shift keying (MPSK) constellations over extended Generalized-K fading with Laplacian noise and using a minimum distance detector. A generic closed form expression of the conditional and the average probability of error is obtained and simplified in terms of the Fox's H function. More simplifications to well known functions for some special cases of fading are also presented. Finally, the mathematical formalism is validated with some numerical results examples done by computer based simulations.

关键词： Detectors Rayleigh channels Probability density function Signal to noise ratio Information theory

来源：评论

学校读者我要写书评

暂无评论

On the low SNR capacity of log-normal turbulence channels with full CSI

On the low SNR capacity of log-normal turbulence channels wi...

引用

International Workshop on Optical Wireless Communications

作者： Fatma Benkhelifa Abdoulaye Tall Zouheir Rezki Mohamed-Slim Alouini Computer Electrical and Mathematical Science and Engineering (CEMSE) Division King Abdullah University of Science and Technology (KAUST) Thuwal Makkah Province Saudi Arabia Orange Labs France

In this paper, we characterize the low signal-to-noise ratio (SNR) capacity of wireless links undergoing the log-normal turbulence when the channel state information (CSI) is perfectly known at both the transmitter and the receiver. We derive a closed form asymptotic expression of the capacity and we show that it scales essentially as λ SNR where λ is the water-filling level satisfying the power constraint. An asymptotically closed-form expression of λ is also provided. Using this framework, we also propose an on-off power control scheme which is capacity-achieving in the low SNR regime.

关键词： Signal to noise ratio Integrated optics Tin Reactive power

来源：评论

学校读者我要写书评

暂无评论

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案：

请选择收藏分类：

通借通还

建议与咨询 留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

时间限定

文献类型

馆藏选择

核心期刊

语言

文献类型

帮助

文字说明：

检索规则说明：

检索范例：

分类表

所选分类

限定检索结果

文献类型

馆藏范围

日期分布

学科分类号

主题

机构

作者

语言

请选择保存的检索档案： 新增检索档案 确定 取消

请选择收藏分类： 新增自定义分类 确定 取消

通借通还

建议与咨询留下您的常用邮箱和电话号码，以便我们向您反馈解决方案和替代方法

请选择保存的检索档案：

请选择收藏分类：