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Electrical and Computer Engineering Faculty Research & Creative Works

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Versatile Optochemical Quantification With Optical Mouse, Altamash Fakki, Salahaldein Ahmed, Jongwon Park, Chang-Soo Kim Aug 2017

Versatile Optochemical Quantification With Optical Mouse, Altamash Fakki, Salahaldein Ahmed, Jongwon Park, Chang-Soo Kim

Electrical and Computer Engineering Faculty Research & Creative Works

There is an ever increasing need for simple, low-cost instruments for ubiquitous medical and environmental measurements in conjunction with networks and Internet-of-things. This work demonstrates that the optical mouse, one of the most common optoelectronic computer peripherals, can be used for chemical quantification. Particularly, we explore the feasibility of using the preassembled optical platform of mouse for oxygen and pH quantification. The image sensor and the light-emitting diode (LED) serve as photodetector and excitation/illumination light source, respectively, while the preinstalled microoptics (e.g., lens and waveguide) provide a fixed optical arrangement convenient for sample analysis. This novel, cost-effective approach demonstrates the …


Secure Transmission With Large Numbers Of Antennas And Finite Alphabet Inputs, Yongpeng Wu, Jun Bo Wang, Jue Wang, Robert Schober, Chengshan Xiao Aug 2017

Secure Transmission With Large Numbers Of Antennas And Finite Alphabet Inputs, Yongpeng Wu, Jun Bo Wang, Jue Wang, Robert Schober, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate secure transmission over the large-scale multiple-antenna wiretap channel with finite alphabet inputs. First, we investigate the case where instantaneous channel state information (CSI) of the eavesdropper is known at the transmitter. We show analytically that a generalized singular value decomposition (GSVD)-based design, which is optimal for Gaussian inputs, may exhibit a severe performance loss for finite alphabet inputs in the high signal-to-noise ratio regime. In light of this, we propose a novel Per-Group-GSVD (PG-GSVD) design, which can effectively compensate the performance loss caused by the GSVD design. More importantly, the computational complexity of the PG-GSVD …


Transient Heterogeneous Electromagnetic Simulation With Dgtd And Behavioral Macromodel, Huan Huan Zhang, Li (Lijun) Jun Jiang, He Ming Yao, Yu Zhang Aug 2017

Transient Heterogeneous Electromagnetic Simulation With Dgtd And Behavioral Macromodel, Huan Huan Zhang, Li (Lijun) Jun Jiang, He Ming Yao, Yu Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

A novel hybrid field-circuit simulation method is proposed for transient heterogeneous electromagnetic simulations. It adopts the discontinuous Galerkin time domain (DGTD) method and behavioral macromodel trained by artificial neural network to analyze the electromagnetic structure and circuit network, respectively. Due to the feature of DGTD method and behavioral macromodel, the proposed method can handle not only electromagnetic structures with complex geometries and materials but also manage circuits with unknown internal details. It provides a new approach that has the trainable accuracy to meet today's IP projection requestions. It is also the first time for DGTD algorithm to work with the …


Discontinuous Galerkin Time-Domain Analysis Of Power/Ground Plate Pairs With Wave Port Excitation, Ping Li, Li (Lijun) Jun Jiang, Hakan Baǧci Jul 2017

Discontinuous Galerkin Time-Domain Analysis Of Power/Ground Plate Pairs With Wave Port Excitation, Ping Li, Li (Lijun) Jun Jiang, Hakan Baǧci

Electrical and Computer Engineering Faculty Research & Creative Works

In this work, a discontinuous Galerkin time-domain method is developed to analyze the power/ground plate pairs taking into account arbitrarily shaped antipads. To implement proper source excitations over the antipads, the magnetic surface current expanded by the electric eigen-modes supported by the corresponding antipad is employed as the excitation. For irregularly shaped antipads, the eigen-modes are obtained by numerical approach. Accordingly, the methodology for the S-parameter extraction is derived based on the orthogonal properties of the different modes. Based on the approach, the transformation between different modes can be readily evaluated.


Electromagnetic-Circuit Cosimulation Based On Hybrid Explicit-Implicit Dgtd And Sbf Macromodel, Ping Yuan, Huan Huan Zhang, Li (Lijun) Jun Jiang, Daniel Garcia Donoro, Yu Zhang Jul 2017

Electromagnetic-Circuit Cosimulation Based On Hybrid Explicit-Implicit Dgtd And Sbf Macromodel, Ping Yuan, Huan Huan Zhang, Li (Lijun) Jun Jiang, Daniel Garcia Donoro, Yu Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

The integrated circuits usually have multiscale feature. If utilizing the explicit discontinuous Galerkin time domain (DGTD) method for electromagnetic-circuit cosimulation, the time step size will be limited to the minimum grid size according to CFL (Courant-Friedrichs-Lewy) condition, which will lead to a small time step size. In order to improve the simulation efficiency, this paper adopts the hybrid explicit-implicit DGTD coupled with the Sigmoidal basis function (SBF) macromodel to achieve electromagnetic-circuit cosimulation.


Analytical Evaluation Of Partial Inductances With Retardation, L. Lombardi, G. Antonini, A. E. Ruehli Jul 2017

Analytical Evaluation Of Partial Inductances With Retardation, L. Lombardi, G. Antonini, A. E. Ruehli

Electrical and Computer Engineering Faculty Research & Creative Works

The Partial Element Equivalent Circuit (PEEC) circuit oriented electromagnetic method has been found particularly useful for modeling PCBs, interconnects, and 3-D problems involving both electromagnetic computations and circuits. Efficiency improvements in PEEC for higher frequencies are becoming important especially for large aspect ratio cells. The analytical solution of the six-fold integrals has been shown to lead to a very efficient solution for such integrals. In this paper we introduce a new approach for the analytical evaluation of retarded partial inductances at arbitrary distances.


Numerical Modeling Of Pcb Power/Ground Plate-Pairs By Dgtd Method Taking Into Account Decoupling Capacitors, Ping Li, Li (Lijun) Jun Jiang, Hakan Baǧci Jul 2017

Numerical Modeling Of Pcb Power/Ground Plate-Pairs By Dgtd Method Taking Into Account Decoupling Capacitors, Ping Li, Li (Lijun) Jun Jiang, Hakan Baǧci

Electrical and Computer Engineering Faculty Research & Creative Works

A discontinuous Galerkin time-domain (DGTD) method is proposed in this work to analyze printed circuit board (PCB) power/ground plate-pair having arbitrarily shaped anti-pads. To apply proper excitation source over the irregular anti-pad, the implemented wave port magnetic current excitation is expanded by the electric eigen-modes of the anti-pad that are calculated via either numerical approach or analytical method. Based on the orthogonality of eigen-modes, the temporal mode expansion coefficient for each mode can be conveniently extracted. Besides, considering the presence of decoupling capacitors, the whole physical system can be split into field and circuit subsystems. For the field subsystem, it …


Fuzzy Color Clustering For Melanoma Diagnosis In Dermoscopy Images, Haidar A. Almubarak, R. Joe Stanley, William V. Stoecker, Randy Hays Moss Jul 2017

Fuzzy Color Clustering For Melanoma Diagnosis In Dermoscopy Images, Haidar A. Almubarak, R. Joe Stanley, William V. Stoecker, Randy Hays Moss

Electrical and Computer Engineering Faculty Research & Creative Works

A fuzzy logic-based color histogram analysis technique is presented for discriminating benign skin lesions from malignant melanomas in dermoscopy images. The approach extends previous research for utilizing a fuzzy set for skin lesion color for a specified class of skin lesions, using alpha-cut and support set cardinality for quantifying a fuzzy ratio skin lesion color feature. Skin lesion discrimination results are reported for the fuzzy clustering ratio over different regions of the lesion over a data set of 517 dermoscopy images consisting of 175 invasive melanomas and 342 benign lesions. Experimental results show that the fuzzy clustering ratio applied over …


Task Assignment And Path Planning For Multiple Autonomous Underwater Vehicles Using 3d Dubins Curves, Wenyu Cai, Meiyan Zhang, Y. Rosa Zheng Jul 2017

Task Assignment And Path Planning For Multiple Autonomous Underwater Vehicles Using 3d Dubins Curves, Wenyu Cai, Meiyan Zhang, Y. Rosa Zheng

Electrical and Computer Engineering Faculty Research & Creative Works

This paper investigates the task assignment and path planning problem for multiple AUVs in three dimensional (3D) underwater wireless sensor networks where nonholonomic motion constraints of underwater AUVs in 3D space are considered. The multi-target task assignment and path planning problem is modeled by the Multiple Traveling Sales Person (MTSP) problem and the Genetic Algorithm (GA) is used to solve the MTSP problem with Euclidean distance as the cost function and the Tour Hop Balance (THB) or Tour Length Balance (TLB) constraints as the stop criterion. The resulting tour sequences are mapped to 2D Dubins curves in the X − …


Electronic Receiver Device Detection System And Method, Jagannathan Sarangapani, Maciej Jan Zawodniok, Vivek Thotla, Mohammad Tayeb Ahmad Ghasr, Jake Hertenstein Jun 2017

Electronic Receiver Device Detection System And Method, Jagannathan Sarangapani, Maciej Jan Zawodniok, Vivek Thotla, Mohammad Tayeb Ahmad Ghasr, Jake Hertenstein

Electrical and Computer Engineering Faculty Research & Creative Works

A super regenerative receiver detection system and method that includes a computing system that stores and executes a cross modulation correlation component to modulate a radio-frequency (RF) stimulation signal that is transmitted in an area using a modulating signal having a first modulating mode, and receive a response UEE signal from the area in which the response UEE signal includes a cross modulated signal emitted from a super regenerative receiver (SRR). The cross modulated signal having a second modulation mode that is different from the first modulation mode. Using this information, the cross modulation correlation component processes the received UEE …


Antenna Design For Small Uav Locator Applications, Randall L. Musselman, Steve Eugene Watkins Jun 2017

Antenna Design For Small Uav Locator Applications, Randall L. Musselman, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

An antenna design problem is presented for a small UAV application. A UAV locator system must include an on-board transmitter with the capability to provide a beacon signal, in the event of a crash, and a receiver that is tailored for a transmitter hunt. This specific context for applying antenna theory allows a variety of design constraints, technical approaches, performance measures, and required results. The paper provides a structure for organizing the material, example approaches that illustrate possible design choices, and recommendations on educational implementation.


A Solution To Low Read Rate Problem In Rfid Scattering Networks, Shadi Ebrahimi-Asl, Mohammad Tayeb Ahmad Ghasr, Maciej J. Zawodniok Jun 2017

A Solution To Low Read Rate Problem In Rfid Scattering Networks, Shadi Ebrahimi-Asl, Mohammad Tayeb Ahmad Ghasr, Maciej J. Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

High interference and low read rate have repeatedly been reported by radio frequency identification (RFID) consumers as the main drawback of passive RFID technology. We investigate a solution to this problem by employing low scattering antennas. We propose a new state of scattering state for RFID tags in that tags will switch to low scattering states to suppress their interference to an established and ongoing backscattering link between an RFID reader and a target tag. We evaluate the efficiency of our proposed solution by random deployment of tags in a network of ten antennas. We show that by using our …


Transient Thermal Analysis Of 3-D Integrated Circuits Packages By The Dgtd Method, Ping Li, Yilin Dong, Min Tang, Junfa Mao, Li (Lijun) Jun Jiang, Hakan Bagci Jun 2017

Transient Thermal Analysis Of 3-D Integrated Circuits Packages By The Dgtd Method, Ping Li, Yilin Dong, Min Tang, Junfa Mao, Li (Lijun) Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

Since accurate thermal analysis plays a critical role in the thermal design and management of the 3-D system-level integration, in this paper, a discontinuous Galerkin time-domain (DGTD) algorithm is proposed to achieve this purpose. Such as the parabolic partial differential equation (PDE), the transient thermal equation cannot be directly solved by the DGTD method. To address this issue, the heat flux, as an auxiliary variable, is introduced to reduce the Laplace operator to a divergence operator. The resulting PDE is hyperbolic, which can be further written into a conservative form. By properly choosing the definition of the numerical flux used …


Microstrip Diplexer With Low Channel-Frequency Ratio, Kirti Dhwaj, Li (Lijun) Jun Jiang, Tatsuo Itoh May 2017

Microstrip Diplexer With Low Channel-Frequency Ratio, Kirti Dhwaj, Li (Lijun) Jun Jiang, Tatsuo Itoh

Electrical and Computer Engineering Faculty Research & Creative Works

The paper presents a microstrip diplexer constructed by joining two stub-perturbed ring resonators at a T-junction. Each ring resonator acts as a bandpass filter with a transmission zero lying very close to the passband of the other filter, thereby increasing the isolation between the two channels. A short stub is additionally added at the T-junction to improve the matching at the common port. The diplexer is able to achieve a channel separation of 50 MHz, with the two channels centered at 2.49 GHz and 2.37 GHz respectively. This translates to a center frequency ratio of 1.05 between the two channels, …


Precoder Design For Simultaneous Wireless Information And Power Transfer With Finite-Alphabet Inputs, Xiaodong Zhu, Weiliang Zeng, Chengshan Xiao May 2017

Precoder Design For Simultaneous Wireless Information And Power Transfer With Finite-Alphabet Inputs, Xiaodong Zhu, Weiliang Zeng, Chengshan Xiao

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, we investigate the mutual information maximization for a multiple-input multiple-output (MIMO) system with simultaneous wireless information and power transfer (SWIPT), where perfect channel state information (CSI) is known at the transmitter. We formulate an optimization problem under the constraints of transmit power and harvested energy. Different from previous work, we assume the input signals to be taken from finite-alphabet inputs instead of Gaussian signals. The formulated problem is NP-hard, so a global optimal solution cannot be found with polynomial time complexity. However, by exploiting the structure of the problem, this optimization problem can be transformed into a …


Fast Monostatic Scattering Analysis Based On Bayesian Compressive Sensing, Huan Huan Zhang, Wei E.I. Sha, Li (Lijun) Jun Jiang May 2017

Fast Monostatic Scattering Analysis Based On Bayesian Compressive Sensing, Huan Huan Zhang, Wei E.I. Sha, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

In conjugation with the method of moments, the Bayesian compressive sensing algorithm is utilized to fast analyze the monostatic electromagnetic scattering problem. Different from the orthogonal matching pursuit based compressive sensing approach that cannot determine the required measurement times, the proposed method overcomes the difficulty by adopting the Bayesian framework to recover the underlying signal. Error bars of the signal can be obtained in the recovery procedure, which offers a way to adaptively determine the number of compressive-sensing measurements.


Multi-Objective Dynamic Economic Dispatch With Demand Side Management Of Residential Loads And Electric Vehicles, Mohammad Rasoul Narimani, Fnu Maigha, Jhi-Young Joo, Mariesa Crow May 2017

Multi-Objective Dynamic Economic Dispatch With Demand Side Management Of Residential Loads And Electric Vehicles, Mohammad Rasoul Narimani, Fnu Maigha, Jhi-Young Joo, Mariesa Crow

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multi-objective optimization method based on the normal boundary intersection is proposed to solve the dynamic economic dispatch with demand side management of individual residential loads and electric vehicles. The proposed approach specifically addresses consumer comfort through acceptable appliance deferral times and electric vehicle charging requirements. The multi-objectives of minimizing generation costs, emissions, and energy loss in the system are balanced in a Pareto front approach in which a fuzzy decision making method has been implemented to find the best compromise solution based on desired system operating conditions. The normal boundary intersection method is described and validated.


Investigating Process-Structure Relations Of Zno Nanofiber Via Electrospinning Method, Ehsan Ghafari, Yining Feng, Yao Liu, Ian T. Ferguson, Na Lu May 2017

Investigating Process-Structure Relations Of Zno Nanofiber Via Electrospinning Method, Ehsan Ghafari, Yining Feng, Yao Liu, Ian T. Ferguson, Na Lu

Electrical and Computer Engineering Faculty Research & Creative Works

1D ZnO nanofibers were fabricated in this study using the electrospinning method through sol-gel approach. The effects of fabrication processing parameters on the nanofibers size have been systematically investigated. The higher concentration of the polymer resulted in a broader distribution of the nanofibers diameter due to non-uniform ejection of the fluid jet. The results indicated that an increase in annealing temperature resulted in a lower diameter size and more uniformity of the nanofiber due to decomposition of PVA. The DSC result confirms that an annealing temperature higher than 480 °C is required to remove the PVA and fully decompose the …


Load Characteristics Of Wireless Power Transfer System With Different Resonant Types And Resonator Numbers, Yiming Zhang, Zhengming Zhao, Kainan Chen, Jun Fan May 2017

Load Characteristics Of Wireless Power Transfer System With Different Resonant Types And Resonator Numbers, Yiming Zhang, Zhengming Zhao, Kainan Chen, Jun Fan

Electrical and Computer Engineering Faculty Research & Creative Works

Wireless Power Transfer (WPT) has been the research focus and applied in many fields. Normally power is transferred wirelessly to charge the battery, which requires specific load characteristics. The load characteristics are essential for the design and operation of the WPT system. This paper investigates the load characteristics of the WPT system with different resonant types and resonator numbers. It is found that in a WPT system with series or LCL resonance under a constant voltage source, the load characteristic is determined by the number of inductors. Even number of inductors results in a constant current characteristic and odd number …


Novel Complementary Metasurfaces For The Orbital Angular Momentum Generation, Menglin L.N. Chen, Li Jun Jiang, Wei E.I. Sha May 2017

Novel Complementary Metasurfaces For The Orbital Angular Momentum Generation, Menglin L.N. Chen, Li Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

Besides amplitude, phase and polarization, wavefront is an important property of electromagnetic (EM) waves. EM waves with twisted wavefronts are known to carry orbital angular momentum (OAM). In this paper, a complementary-type metasurface is proposed to generate an OAM beam at microwave regime. Two metasurfaces that can produce OAM of order 2 and 4 are designed. By using our novel design methods, which are based on circuit model and dyadic Green's function, a high conversion efficiency has been achieved with a very low profile.


Surface Waves Extraction And Their Effect On Effective Material Parameters Of Metamaterials, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha Apr 2017

Surface Waves Extraction And Their Effect On Effective Material Parameters Of Metamaterials, Xiaoyan Y.Z. Xiong, Li (Lijun) Jun Jiang, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

We investigate the influence of the finite width of the metamaterial slabs. The surface waves excited in finite-width slabs are numerically extracted by the rigorous coupled-wave analysis method. The magnitudes and decay rates of surface waves are analyzed for different materials and geometries. A general homogenization method based on the analysis of appropriately defined macroscopic fields in metamaterial cells is proposed to retrieve the effective material parameters as functions of position. The effects of surface waves on effective material parameters are studied.


Nanoselective Area Growth Of Defect-Free Thick Indium-Rich Ingan Nanostructures On Sacrificial Zno Templates, Renaud Puybaret, David J. Rogers, Youssef El Gmili, Suresh Sundaram, Matthew B. Jordan, Xin Li, Gilles Patriarche, Ferechteh H. Teherani, Eric V. Sandana, Philippe Bove, Paul L. Voss, Ryan Mcclintock, Manijeh Razeghi, Ian Ferguson Apr 2017

Nanoselective Area Growth Of Defect-Free Thick Indium-Rich Ingan Nanostructures On Sacrificial Zno Templates, Renaud Puybaret, David J. Rogers, Youssef El Gmili, Suresh Sundaram, Matthew B. Jordan, Xin Li, Gilles Patriarche, Ferechteh H. Teherani, Eric V. Sandana, Philippe Bove, Paul L. Voss, Ryan Mcclintock, Manijeh Razeghi, Ian Ferguson

Electrical and Computer Engineering Faculty Research & Creative Works

Nano selective area growth (NSAG) by metal organic vapor phase epitaxy of high-quality InGaN nanopyramids on GaN-coated ZnO/c-sapphire is reported. Nanopyramids grown on epitaxial low-temperature GaN-on-ZnO are uniform and appear to be single crystalline, as well as free of dislocations and V-pits. They are also indium-rich (with homogeneous 22% indium incorporation) and relatively thick (100 nm). These properties make them comparable to nanostructures grown on GaN and AlN/Si templates, in terms of crystallinity, quality, morphology, chemical composition and thickness. Moreover, the ability to selectively etch away the ZnO allows for the potential lift-off and transfer of the InGaN/GaN nanopyramids onto …


Mixing Of Spin And Orbital Angular Momenta Via Second-Harmonic Generation In Plasmonic And Dielectric Chiral Nanostructures, Xiaoyan Y.Z. Xiong, Ahmed Al-Jarro, Li (Lijun) Jun Jiang, Nicolae C. Panoiu, Wei E.I. Sha Apr 2017

Mixing Of Spin And Orbital Angular Momenta Via Second-Harmonic Generation In Plasmonic And Dielectric Chiral Nanostructures, Xiaoyan Y.Z. Xiong, Ahmed Al-Jarro, Li (Lijun) Jun Jiang, Nicolae C. Panoiu, Wei E.I. Sha

Electrical and Computer Engineering Faculty Research & Creative Works

We present a theoretical study of the characteristics of the nonlinear spin-orbital angular momentum coupling induced by second-harmonic generation in plasmonic and dielectric nanostructures made of centrosymmetric materials. In particular, the connection between the phase singularities and polarization helicities in the longitudinal components of the fundamental and second-harmonic optical fields and the scatterer symmetry properties are discussed. By in-depth comparison between the interaction of structured optical beams with plasmonic and dielectric nanostructures, we have found that all-dielectric and plasmonic nanostructures that exhibit magnetic and electric resonances have comparable second-harmonic conversion efficiency. In addition, mechanisms for second-harmonic enhancement for single and …


Design Of Dual Loaded Rfid Tag For Higher Order Modulations, Shadi Ebrahimi-Asl, Mohammad Tayeb Ahmad Ghasr, Maciej Jan Zawodniok Apr 2017

Design Of Dual Loaded Rfid Tag For Higher Order Modulations, Shadi Ebrahimi-Asl, Mohammad Tayeb Ahmad Ghasr, Maciej Jan Zawodniok

Electrical and Computer Engineering Faculty Research & Creative Works

Methods, systems, and apparatus for an improved antenna, specifically a T-match bowtie antenna system, including a t-match antenna having a first side and a second side, wherein the antenna is dual loaded; a first load soldered to the first side of the antenna; a second load soldered to the second side of the antenna; and a gap defined by the space between the first load and the second load, wherein the gap is approximately one millimeter; where the antenna is capable of providing quasi-32-QAM encoding.


Machine Learning Based Mom (Ml-Mom) For Parasitic Capacitance Extractions, He Ming Yao, Yu Wei Qin, Li (Lijun) Jun Jiang Apr 2017

Machine Learning Based Mom (Ml-Mom) For Parasitic Capacitance Extractions, He Ming Yao, Yu Wei Qin, Li (Lijun) Jun Jiang

Electrical and Computer Engineering Faculty Research & Creative Works

This paper is a rethinking of the conventional method of moments (MoM) using the modern machine learning (ML) technology. By repositioning the MoM matrix and unknowns in an artificial neural network (ANN), the conventional linear algebra MoM solving is changed into a machine learning training process. The trained result is the solution. As an application, the parasitic capacitance extraction broadly needed by VLSI modeling is solved through the proposed new machine learning based method of moments (ML-MoM). The multiple linear regression (MLR) is employed to train the model. The computations are done on Amazon Web Service (AWS). Benchmarks demonstrated the …


Linear Precoding For Fading Cognitive Multiple-Access Wiretap Channel With Finite-Alphabet Inputs, Juening Jin, Chengshan Xiao, Meixia Tao, Wen Chen Apr 2017

Linear Precoding For Fading Cognitive Multiple-Access Wiretap Channel With Finite-Alphabet Inputs, Juening Jin, Chengshan Xiao, Meixia Tao, Wen Chen

Electrical and Computer Engineering Faculty Research & Creative Works

We investigate the fading cognitive multiple-access wiretap channel (CMAC-WT), in which two secondary-user transmitters (STs) send secure messages to a secondary-user receiver (SR) in the presence of an eavesdropper and subject to interference threshold constraints at multiple primary-user receivers (PRs). We design linear precoders to maximize the average secrecy sum rate for a multiple-input-multiple-output (MIMO) fading CMAC-WT under finite-alphabet inputs and statistical channel state information at STs. For this nondeterministic polynomial-time NP-hard problem, we utilize an accurate approximation of the average secrecy sum rate to reduce the computational complexity and then present a two-layer algorithm by embedding the convex-concave procedure …


Stress And Thermal Characterization Of 4h-Sic Microelectromechanical Structures, Colton Wells, Jheng Yi Jiang, Ting Fu Chang, Chih Fang Huang, Jiaxin Ke, Weijun Luo, Guangrui Xia, Kuan Yew Cheong, Feng Zhao Mar 2017

Stress And Thermal Characterization Of 4h-Sic Microelectromechanical Structures, Colton Wells, Jheng Yi Jiang, Ting Fu Chang, Chih Fang Huang, Jiaxin Ke, Weijun Luo, Guangrui Xia, Kuan Yew Cheong, Feng Zhao

Electrical and Computer Engineering Faculty Research & Creative Works

In this letter, the potential of single crystalline 4H-polytype silicon carbide (4H-SiC) based microelectromechanical structures as resistance thermometer for high temperature sensing were explored. A dopant-selective photoelectrochemical etching process was applied to release the sensing element – suspended microstructures on 4H-SiC substrate. Residual stress and stress gradient in the microstructure before and after release was examined by micro-Raman spectroscopy. Electrical resistance of the suspended microstructures at different temperatures were characterized and analyzed by a temperature-dependent electron mobility model.


Sure: A Novel Approach For Self Healing Battery Starved Users Using Energy Harvesting, Mohamed Y. Selim, Ahmad Alsharoa, Ahmed E. Kamal, Mohammed Alnuem Mar 2017

Sure: A Novel Approach For Self Healing Battery Starved Users Using Energy Harvesting, Mohamed Y. Selim, Ahmad Alsharoa, Ahmed E. Kamal, Mohammed Alnuem

Electrical and Computer Engineering Faculty Research & Creative Works

Radio Frequency (RF) energy harvesting holds a promising future for energizing low power mobile devices in next generation wireless networks. Harvesting from a dedicated RF energy source acquires much more energy than simply harvesting from ambient RF sources. In this paper, novel Self-healing of Users equipment by RF Energy transfer scheme is introduced between the network operator and battery starved users to heal and extend their battery life time by sending dedicated energy from different sources in order to be aggregated and harvested by starved users. This approach depends on the concept of Energy as a Service where the network …


Hypothetical Cases In Engineering Ethics, Steve Eugene Watkins Mar 2017

Hypothetical Cases In Engineering Ethics, Steve Eugene Watkins

Electrical and Computer Engineering Faculty Research & Creative Works

An important educational subject for engineering students is engineering ethics. Common instructional objectives are to develop knowledge of ethical principles, e.g. professional codes, and to apply these principles to specific situations. Case studies are useful instructional examples and exercises and cases are central to student ethics competitions. Historical case studies emphasize the relevance of ethics in engineering work. Hypothetical case studies can address specific ethical principles and provide great design flexibility. This paper discusses hypothetical cases in engineering ethics in the context of instructional exercises or student competitions. Recommendations are given for the development of versatile cases and for approaching …


Transient Analysis Of Dispersive Power-Ground Plate Pairs With Arbitrarily Shaped Antipads By The Dgtd Method With Wave Port Excitation, Ping Li, Li Jun Jiang, Hakan Bagci Feb 2017

Transient Analysis Of Dispersive Power-Ground Plate Pairs With Arbitrarily Shaped Antipads By The Dgtd Method With Wave Port Excitation, Ping Li, Li Jun Jiang, Hakan Bagci

Electrical and Computer Engineering Faculty Research & Creative Works

A discontinuous Galerkin time-domain (DGTD) method analyzing signal/power integrity on multilayered power-ground parallel plate pairs is proposed. The excitation is realized by introducing wave ports on the antipads where electric/magnetic current sources are represented in terms of the eigenmodes of the antipads. Since closed-forms solutions do not exist for the eigenmodes of the arbitrarily shaped antipads, they have to be calculated using numerical schemes. Spatial orthogonality of the eigenmodes permits determination of each mode's temporal expansion coefficient by integrating the product of the electric field and the mode over the wave port. The temporal mode coefficients are then Fourier transformed …