检索结果-内蒙古大学图书馆

Antennas and Propagation Society International Symposium

作者： Doolos Aibek Uulu Rui Chen Liang Chen Ping Li Hakan Bagci Division of Computer Electrical and Mathematical Science and Engineering King Abdullah University of Science and Technology (KAUST) Thuwal Saudi Arabia Department of Mathematics and Natural Sciences University of Central Asia (UCA) Naryn Kyrgyzstan Key Laboratory of Ministry of Education of Design and Electromagnetic Compatibility of High-Speed Electronic Systems Shanghai Jiao Tong University Shanghai China

A coupled system of volume integral and hydrodynamic equations is formulated to analyze electromagnetic scattering from composite plasmonic structures involving a metal-metal interface. This coupled system in unknowns electric flux and free electron velocity is discretized using Schaubert-Wilton-Glisson basis functions. Inserting these expansions into the coupled system of equations and applying Galerkin testing yield a matrix equation. Two-level iterative scheme is used to solve this matrix equation for the unknown expansion coefficients. To demonstrate the accuracy of the proposed method, numerical results are compared to those obtained using an extended Mie series approach that takes into account the hydrodynamic equation and the boundary conditions it requires.

关键词：

来源：评论

学校读者我要写书评

暂无评论

Unbiased Parameter Inference for a Class of Partially Observed LÃ©vy-Process Models

arXiv

引用

arXiv 2021年

作者： Ruzayqat, Hamza Jasra, Ajay Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia

We consider the problem of static Bayesian inference for partially observed LÃ©vy-process models. We develop a methodology which allows one to infer static parameters and some states of the process, without a bias from the time-discretization of the afore-mentioned LÃ©vy process. The unbiased method is exceptionally amenable to parallel implementation and can be computationally efficient relative to competing approaches. We implement the method on S & P 500 log-return daily data and compare it to some Markov chain Monte Carlo (MCMC) *** Codes 65C05, 60H35, 62M05, 62M20, 62F15 © 2021, CC BY.

关键词： Bayesian networks

来源：评论

学校读者我要写书评

暂无评论

Size Optimized Antenna-in-Package with Quasi-Isotropic Radiation Pattern

Size Optimized Antenna-in-Package with Quasi-Isotropic Radia...

引用

IEEE International Symposium on Antennas and Propagation

作者： Maria Bermudez Arboleda Kirill Klionovski Atif Shamim Computer Electrical and Mathematical Sciences and Engineering (CEMSE) King Abdullah University of Science and Technology KAUST Thuwal Kingdom of Saudi Arabia

ISBN: (纸本)9781728146713

The Internet of Things applications require small wireless sensors with quasi-isotropic radiation, so that their communication is orientation insensitive. A method to realize quasi-isotropic antenna is by placing multiple radiators on the faces of a cube, which also acts as a package for the embedded electronics. In this work, we demonstrate quasi-isotropic radiation through a 3D Antenna-in-Package with multiple magnetic Hertzian dipole radiators. For quasi-isotropy, the dipoles on four faces of the cube must be in phase, while the dipoles orthogonal to the plane carrying the other four dipoles must be 60° out of phase. With this feeding arrangement, an isotropy of 7.3 dB has been achieved in the whole radiation sphere in simulations and 6.5 dB in a prototype where the ideal dipoles were replaced by practical microstrip patch antennas. The inner walls of the cube have been metallized to provide effective shielding between the antennas and the embedded electronics. We also optimized the size of the cube while maintaining a decent isolation between the adjacent patches so that the required quasi-isotropic radiation can be achieved. It is observed that the isotropy increases by reducing the size of the cube until the coupling between the multiple radiators starts to negatively affect it. As a trade-off between size, acceptable coupling and decent isotropy, a cube with λ_o/2 sides has been designed, prototyped and tested.

关键词： Couplings Antenna measurements Wireless communication Wireless sensor networks Dipole antennas Patch antennas Prototypes

来源：评论

学校读者我要写书评

暂无评论

Enabling the Internet of bodies through capacitive body channel access schemes

TechRxiv

引用

TechRxiv 2021年

作者： Celik, Abdulkadir Eltawil, Ahmed M. The Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal 23955-6900 Saudi Arabia

The Internet of Bodies (IoB) is an imminent extension of the vast Internet of things (IoT) domain, where wearable, ingestible, injectable, and implantable smart objects form a network in, on, and around the human body. Even though on-body IoB communications are required to occur within very close proximity of the human body, on-body wireless radio frequency (RF) IoB devices unnecessarily extend the coverage range beyond the human body due to their radiative nature. This eventually reduces energy efficiency, causes co-existence and interference issues, and exposes sensitive personal data to security threats. Alternatively, capacitive body channel communications (BCC) exhibit much less signal leakage by confining signal transmission to the human body and experience substantially less propagation loss than RF systems as body tissues has better conductivity than surrounding air. Furthermore, the BCC band (10-100 MHz) decouples the transceiver size from the carrier wavelength, eliminating the need for complex and power-hungry radio front-ends. Therefore, capacitive BCC is a key enabler to reach the ultimate design goals of ultra-low-power, high throughput, and small form-factor IoB devices. Albeit these attractive features, the communication and networking aspects of the capacitive BCC are not thoroughly explored yet. This paper is the first to model orthogonal and non-orthogonal body channel access schemes with or without cooperation among the IoB nodes. In order to address the quality of service (QoS) demand scenarios of different IoB applications, we present and formulate max-min rate, max-sum rate, and QoS sufficient operational regimes, then provide solution methodologies for optimal power and phase time allocations. Extensive numerical results are analyzed to compare the performance of orthogonal and non-orthogonal schemes with and without cooperation for various design parameters under prescribed QoS regimes. © 2021, CC BY.

关键词： Internet of things

来源：评论

学校读者我要写书评

暂无评论

A Robust Subtree-Based Authentication Scheme for TMIS Using Chaotic Hash Function

A Robust Subtree-Based Authentication Scheme for TMIS Using ...

引用

International Conference on computer, Information and Telecommunication Systems (CITS)

作者： Chandrashekhar Meshram Mohammad S. Obaidat Balqies Sadoun Agbotiname Lucky Imoize Vishesh P. Gaikwad Department of Post Graduate Studies and Research in Mathematics Jayawanti Haksar Government Post Graduate College College of Chhindwara University Betul M.P. India King Abdullah II School of Information Technology University of Jordan Amman Jordan University of Science and Technology Beijing Beijing China SRM University SRM Nagar Kattankulathur TN India Amity University Noida UP India College of Engineering Al-Balqa’ Applied University Al-Salt Jordan Department of Electrical and Electronics Engineering Faculty of Engineering University of Lagos Akoka Lagos Nigeria Department of Electrical Engineering and Information Technology Institute of Digital Communication Ruhr University Bochum Germany Department of Computer Science and Engineering Sardar Vallabhbhai National Institute of Technology Surat Gujarat India

ISBN: (数字)9798350359091

ISBN: (纸本)9798350359107

The widespread availability of broadband telecommunication and the relatively affordable cost of vital signs monitoring devices have enabled telemedicine to bring its benefits directly to patients' homes. In contemporary healthcare, Telecare Medicine Information System (TMIS) facilitates remote disease diagnosis, treatment, and healthcare delivery through the capabilities of wireless communication and information technology. To protect patient confidentiality, TMIS must develop robust authentication systems since it operates on the public Internet, which exposes its operations to security vulnerabilities. To ensure patient privacy, we present a novel Subtree-based Authentication technique for TMIS. An evaluation of the proposed scheme reveals that it is resistant to known potential attacks, and offers more security effectiveness and resource efficiency than existing schemes, making it an excellent solution for enhancing the security of TMIS implementations.

关键词： Privacy Chaotic communication Telemedicine Authentication Passwords Internet Security

来源：评论

学校读者我要写书评

暂无评论

BUSIFusion: Blind Unsupervised Single Image Fusion of Hyperspectral and RGB Images

TechRxiv

引用

TechRxiv 2022年

作者： Li, Jiabao Li, Yuqi Wang, Chong Ye, Xulun Heidrich, Wolfgang The Faculty of Electrical Engineering and Computer Science Ningbo University Ningbo315600 China Zhejiang Engineering Research Center of Advanced Mass Spectrometry and Clinical Application China The Visual Computing Center King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia

Hyperspectral images (HSIs) provide rich spectral information that has been widely used in numerous computer vision tasks. However, their low spatial resolution often prevents their use in applications such as image segmentation and recognition. Fusing low-resolution HSIs with high-resolution RGB images to reconstruct high-resolution HSIs has attracted great research attention recently. In this paper, we propose an unsupervised blind fusion network that operates on a single HSI and RGB image pair and requires neither known degradation models nor any training data. Our method takes full advantage of an unrolling network and coordinate encoding to provide a state-of-the-art HSI reconstruction. It can also estimate the degradation parameters relatively accurately through the neural representation and implicit regularization of the degradation model. The experimental results demonstrate the effectiveness of our method both in simulations and in our real experiments. The proposed method outperforms other state-of-the-art nonblind and blind fusion methods on two popular HSI datasets. Our related code and data is available at https://***/CPREgroup/Real-Spec-RGB-Fusion. © , CC BY-NC-SA.

关键词： Image fusion

来源：评论

学校读者我要写书评

暂无评论

Fast Tracking of Maximum Power in a Shaded Photovoltaic System Using Ali Baba and the Forty Thieves (AFT) Algorithm

引用

Processes 2023年第10期11卷

作者： Rehman, Khalil Ur Sajid, Injila Lu, Shiue-Der Ahmad, Shafiq Liu, Hwa-Dong Bakhsh, Farhad Ilahi Tariq, Mohd Sarwar, Adil Lin, Chang-Hua Department of Electrical Engineering ZHCET Aligarh Muslim University Aligarh202002 India Department of Electrical Engineering National Chin-Yi University of Technology Taichung411 Taiwan Industrial Engineering Department College of Engineering King Saud University Riyadh11421 Saudi Arabia Undergraduate Program of Vehicle and Energy Engineering National Taiwan Normal University Taipei106 Taiwan Department of Electrical Engineering National Institute of Technology Srinagar190006 India Department of Electrical and Computer Engineering Florida International University MiamiFL33174 United States Department of Electrical Engineering National Taiwan University of Science and Technology Taipei106 Taiwan

Photovoltaic (PV) generation systems that are partially shaded have a non-linear operating curve that is highly dependent on temperature and irradiance conditions. Shading from surrounding objects like clouds, trees, and buildings creates partial shading conditions (PSC) that can cause hot spot formation on PV panels. To prevent this, bypass diodes are installed in parallel across each panel, resulting in a global maximum power point (GMPP) and multiple local maximum power points (LMPPs) on the power-voltage (P-V) curve. Traditional methods for maximum power point tracking (MPPT), such as perturb and observe (P&O) and incremental conductance (INC), converge for LMPPs on the P-V curve, but metaheuristic algorithms can track the GMPP effectively. This paper proposes a new, efficient, and robust GMPP tracking technique based on a nature-inspired algorithm called Ali Baba and the Forty Thieves (AFT). Utilizing the AFT algorithm for MPPT in PV systems has several novel features and advantages, including its adaptability, exploration-exploitation balance, simplicity, efficiency, and innovative approach. These characteristics make AFT a promising choice for enhancing the efficiency of PV systems under varied circumstances. The performance of the proposed method in tracking the GMPP is evaluated using a simulation model under MATLAB/Simulink environment, the achieved simulation results are compared to particle swarm optimization (PSO). The proposed method is also tested in real-time using the Hardware-in-the-loop (HIL) emulator to validate the achieved simulation results. The findings indicate that the proposed AFT-based GMPP tracking method performs better under complex partial irradiance conditions than PSO. © 2023 by the authors.

关键词： Efficiency

来源：评论

学校读者我要写书评

暂无评论

Sub-structure Characteristic Mode Analysis of Microstrip Antennas Using a Global Multi-trace Formulation

arXiv

引用

arXiv 2022年

作者： Zhao, Ran Lu, Yuyu Cheng, Guang Shang Zhu, Wei Hu, Jun Bagci, Hakan Chengdu611731 China The Electrical and Computer Engineering Program Computer Electrical and Mathematical Science and Engineering Division King Abdullah University of Science and Technology Thuwal23955 Saudi Arabia The Information Materials and Intelligent Sensing Laboratory of Anhui Province Anhui University Hefei230601 China The Anhui Province Key Laboratory of Target Recognition and Feature Extraction Lu’an237010 China Thuwal23955 Saudi Arabia

A characteristic mode (CM) method that relies on a global multi-trace formulation (MTF) of surface integral equations is proposed to compute the modes and the resonance frequencies of microstrip patch antennas with finite dielectric substrates and ground planes. Compared to the coupled formulation of electric field and Poggio-Miller-Chang-Harrington-Wu-Tsai integral equations, global MTF allows for more direct implementation of a sub-structure CM method. This is achieved by representing the coupling of the electromagnetic fields on the substrate and ground plane in the form of a numerical Green function matrix, which yields a more compact generalized eigenvalue equation. The resulting sub-structure CM method avoids the cumbersome computation of the multilayered medium Green function (unlike the CM methods that rely on mixed-potential integral equations) and the volumetric discretization of the substrate (unlike the CM methods that rely on volume-surface integral equations), and numerical results show that it is a reliable and accurate approach to predicting the modal behavior of electromagnetic fields on practical microstrip antennas. Copyright © 2022, The Authors. All rights reserved.

关键词： Microstrip antennas

来源：评论

学校读者我要写书评

暂无评论

Unbiased estimation of the Hessian for partially observed diffusions

arXiv

引用

arXiv 2021年

作者： Chada, Neil K. Jasra, Ajay Yu, Fangyuan Computer Electrical and Mathematical Sciences and Engineering Division King Abdullah University of Science and Technology Thuwal23955-6900 Saudi Arabia

In this article we consider the development of unbiased estimators of the Hessian, of the log-likelihood function with respect to parameters, for partially observed diffusion processes. These processes arise in numerous applications, where such diffusions require derivative information, either through the Jacobian or Hessian matrix. As time-discretizations of diffusions induce a bias, we provide an unbiased estimator of the Hessian. This is based on using Girsanov’s Theorem and randomization schemes developed through Mcleish [25] and Rhee & Glynn [27]. We demonstrate our developed estimator of the Hessian is unbiased, and one of finite variance. We numerically test and verify this by comparing the methodology here to that of a newly proposed particle filtering methodology. We test this on a range of diffusion models, which include different Ornstein–Uhlenbeck processes and the Fitzhugh–Nagumo model, arising in neuroscience. © 2021, CC BY.

关键词： Diffusion

来源：评论

学校读者我要写书评

暂无评论

Optimizing Photovoltaic Power Production in Partial Shading Conditions Using Dandelion Optimizer (DO)-Based MPPT Method

引用

Processes 2023年第8期11卷

作者： Sajid, Injila Gautam, Ayushi Sarwar, Adil Tariq, Mohd Liu, Hwa-Dong Ahmad, Shafiq Lin, Chang-Hua Sayed, Abdelaty Edrees Department of Electrical Engineering ZHCET Aligarh Muslim University Aligarh202002 India Department of Electrical and Computer Engineering Florida International University MiamiFL33174 United States Undergraduate Program of Vehicle and Energy Engineering National Taiwan Normal University Taipei106 Taiwan Industrial Engineering Department College of Engineering King Saud University Riyadh11421 Saudi Arabia Department of Electrical Engineering National Taiwan University of Science and Technology Taipei106 Taiwan

This research proposes the dandelion optimizer (DO), a bioinspired stochastic optimization technique, as a solution for achieving maximum power point tracking (MPPT) in photovoltaic (PV) arrays under partial shading (PS) conditions. In such scenarios, the overall power output of the PV array is adversely affected, with shaded cells generating less power and consuming power themselves, resulting in reduced efficiency and local hotspots. While bypass diodes can be employed to mitigate these effects by redirecting current around shaded cells, they may cause multiple peaks, making MPPT challenging. Therefore, metaheuristic algorithms are suggested to effectively optimize power output and handle multiple peaks. The DO algorithm draws inspiration from the long-distance movement of a dandelion seed, which relies on the force of the wind. By utilizing this bioinspired approach, the DO algorithm can successfully capture the maximum power point (MPP) under different partial shading scenarios, where traditional MPPT algorithms often struggle. An essential contribution of this research lies in the examination of the performance of the proposed algorithm through simulation and real-time hardware-in-the-loop (HIL) results. Comparing the DO algorithm with the state-of-the-art algorithms, including particle swarm optimization (PSO) and cuckoo search (CS), the DO algorithm outperforms them in terms of power tracking efficiency, tracking duration, and the maximum power tracked. Based on the real-time HIL results, the DO algorithm achieves the highest average efficiency at 99.60%, surpassing CS at 96.46% and PSO at 94.74%. These findings demonstrate the effectiveness of the DO algorithm in enhancing the performance of MPPT in PV arrays, particularly in challenging partial shading conditions. © 2023 by the authors.

关键词： Efficiency

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：