Electrical and Computer Engineering Commons^™

Printed Triple-Band Circularly Polarised Antenna For Wireless Systems, Xiulong Bao, Max Ammann

Articles

A triple-band circularly polarised microstrip patch antenna operating in the 2.4, 3.5 and 5.7 GHz bands is presented. The antenna consists of two substrate layers with an electromagnetically coupled low-band patch in the middle layer and a probe-fed dual-band patch on the top layer. The impedance bandwidths (voltage standing wave ratio (VSWR) < 2.5) for the three frequency bands are 112, 118 and 427 MHz with 3 dB axial-ratio bandwidths of 15, 44 and 36 MHz, respectively. The peak gains across the operating bands are 4.2, 5.5 and 4 dBic, respectively.

Miniature Printed Antennas And Filters Using Volumetric Reactive Pins And Lumped Circuit Loadings, Saurabh Gupta

USF Tampa Graduate Theses and Dissertations

This dissertation presents a new technique for miniaturization of printed RF circuits and antennas. The technique is based on lumped circuit elements and volumetric reactive pin loadings. The vertical arrangement of the pins is shown to provide a meandered current path within the device volume enhancing the miniaturization achieved with sole application of lumped circuit components. The technique is applied for antenna and filter size reduction. In antenna applications, it is shown that due to the presence of the reactive pin loading the overall size of a printed antenna can be miniaturized without affecting the radiation efficiency performance. One of …

Miniature Ion Optics Towards A Micro Mass Spectrometer, Ashish Chaudhary

USF Tampa Graduate Theses and Dissertations

This PhD dissertation reports the development of miniature ion optics components of a mass spectrometer (MS) with the ultimate goal to lay the foundation for a compact low-power micromachined MS (µMS) for broad-range chemical analysis. Miniaturization of two specific components a) RF ion traps and b) an ion funnel have been investigated and miniature low-power versions of these components have been developed and demonstrated successfully in lab experiments. Power savings, simpler electronics and packaging schemes required to operate the micro-scale RF cylindrical ion traps have been the key motivation driving this research. Microfabricated cylindrical ion traps (µCITs) and arrays in …

On The Improvement Of The Capacity Of The Heterogeneous Networks With Link-Level And System-Level Approaches, Mehmet Bahadır Çelebi

USF Tampa Graduate Theses and Dissertations

Evolution of wireless services enabled the development of the advanced applications and shifted the paradigms of research in this field from voice to data centric. Such services are spreading like wildfire between users and hence, increasing the demand for large bandwidth. However, the frequency spectrum that is suitable for wireless mobile communications is already assigned to particular services from 400 MHz to several GHz. Also, allocating a large chunk of band continuously from the same part of the spectrum may not be possible due to spectral crowd. Therefore, meeting the demand for high data rate requiring wireless services within the …

Fabrication And Comparison Of Electrospun Cobalt Oxide-Antimony Doped Tin Oxide (Coo-Ato) Nanofibers Made With Ps: D-Limonene And Ps: Toluene, Manopriya Devisetty Subramanyam

USF Tampa Graduate Theses and Dissertations

This work investigates the fabrication, process optimization, and characterization of cobalt oxide-antimony doped tin oxide (CoO-ATO) nanofibersusing polystyrene (PS) solutions with toluene orD-limonene as solvents. These nanofibers are produced by anelectrospinning process. Nanofibers are fabricated using polymeric solutions of CoO doped ATO and mixtures of PS: D-limonene and PS:toluene. PSis a base aromatic organic polymer, a non-toxic material, and a versatile catalyst for fiber formation. PSsolutions are made by mixing polystyrene beads and D-limonene or toluene at specific weight percentages. These polymeric solutions of PS: D-limonene and PS:toluene are then mixed with CoO-ATO at various weight percentages. The two solutions …

Solar Power Deployment: Forecasting And Planning, Mohana Shandal Alanazi

Electronic Theses and Dissertations

The rapid growth of Photovoltaic (PV) technology has been very visible over the past decade. Recently, the penetration of PV plants to the existing grid has significantly increased. Such increase in the integration of solar energy has brought attention to the solar irradiance forecasting. This thesis presents a thorough research of PV technology, how solar power can be forecasted, and PV planning under uncertainty.

Over the last decade, the PV was one of the fastest growing renewable energy technologies. However, the PV system output varies based on weather conditions. Due to the variability and the uncertainty of solar power, the …

Hosting Capacity Calculations In Power Systems, Mansoor T. Alturki

Electronic Theses and Dissertations

The aim of this thesis is to investigate and calculate Hosting Capacity in power systems to identify the maximum amount of renewable energy resources that can be deployed. After connecting distributed generation to distribution system, the performance index of the distribution system will improve or deteriorate. The point which is between the acceptable deterioration and unacceptable deterioration is the hosting capacity. This research is specifically concerned with the effect of increasing distributed generation on the performance index in distribution networks and finding the maximum point of the acceptable deterioration.

The hosting capacity is the amount of distributed generation that can …

Statistical Scheduling Of Economic Dispatch And Energy Reserves Of Hybrid Power Systems With High Renewable Energy Penetration, Yi Gu

Electronic Theses and Dissertations

A statistical scheduling approach to economic dispatch and energy reserves is proposed in this paper. The proposed approach focuses on minimizing the overall power operating cost with considerations of renewable energy uncertainty and power system security. A hybrid power system generates electricity from both conventional and renewable energy sources. In such a system, it is challenging and yet an open question on the scheduling of economic dispatch together with energy reserves, due to renewable energy generation uncertainty, and spatially wide distribution of energy resources. The hybrid power system scheduling is formulated as a convex programming problem to minimize power operating …

Condition Monitoring System Of Wind Turbine Generators, Khaled Bubaker Abdusamad

Electronic Theses and Dissertations

The development and implementation of the condition monitoring systems (CMS) play a significant role in overcoming the number of failures in the wind turbine generators that result from the harsh operation conditions, such as over temperature, particularly when turbines are deployed offshore. In order to increase the reliability of the wind energy industry, monitoring the operation conditions of wind generators is essential to detect the immediate faults rapidly and perform appropriate preventative maintenance. CMS helps to avoid failures, decrease the potential shutdowns while running, reduce the maintenance and operation costs and maintain wind turbines protected. The knowledge of wind turbine …

A New Transfer Impedance Based System Equivalent Model For Voltage Stability Analysis, Yang Wang, Caisheng Wang, Feng Lin, Wenyuan Li, Le Yi Wang, Junhui Zhao

Electrical & Computer Engineering and Computer Science Faculty Publications

This paper presents a new transfer impedance based system equivalent model (TISEM) for voltage stability analysis. The TISEM can be used not only to identify the weakest nodes (buses) and system voltage stability, but also to calculate the amount of real and reactive power transferred from the generator nodes to the vulnerable node causing voltage instability. As a result, a full-scale view of voltage stability of the whole system can be presented in front of system operators. This useful information can help operators take proper actions to avoid voltage collapse. The feasibility and effectiveness of the TISEM are further validated …

Simulation Of A Rising Sun Magnetron Employing A Faceted Cathode With A Continuous Current Source, Sulmer Fernandez-Gutierrez, Jim Browning, Ming-Chieh Lin, David N. Smithe, Jack Watrous

Electrical and Computer Engineering Faculty Publications and Presentations

It has been proposed that gated field emitters could be used in place of conventional thermionic cathodes to control the current injection in a magnetron, both temporally and spatially. Since gated field emitters have to be fabricated on flat surfaces, a faceted cathode would be used to implement this approach. A 2D ten cavity, rising sun magnetron has been modeled using the particle-in-cell code VORPAL. Cylindrical, five-sided, and ten-sided faceted cathodes were modeled to study the variation of magnetron operation due to the cathode shape. This work shows the results of the device performance employing three different cathode geometries with …

Cubic Spline Interpolation By Solving A Recurrence Equation Instead Of A Tridiagonal Matrix, Peter Revesz

School of Computing: Conference and Workshop Papers

The cubic spline interpolation method is proba- bly the most widely-used polynomial interpolation method for functions of one variable. However, the cubic spline method requires solving a tridiagonal matrix-vector equation with an O(n) computational time complexity where n is the number of data measurements. Even an O(n) time complexity may be too much in some time-ciritical applications, such as continuously estimating and updating the flight paths of moving objects. This paper shows that under certain boundary conditions the tridiagonal matrix solving step of the cubic spline method could be entirely eliminated and instead the coefficients of the unknown cubic polynomials …

Predicting Solar Irradiance Using Time Series Neural Networks, Ahmad Alzahrani, Jonathan W. Kimball, Cihan H. Dagli

Electrical and Computer Engineering Faculty Research & Creative Works

Increasing the accuracy of prediction improves the performance of photovoltaic systems and alleviates the effects of intermittence on the systems stability. A Nonlinear Autoregressive Network with Exogenous Inputs (NARX) approach was applied to the Vichy-Rolla National Airport's photovoltaic station. The proposed model uses several inputs (e.g. time, day of the year, sky cover, pressure, and wind speed) to predict hourly solar irradiance. Data obtained from the National Solar Radiation Database (NSRDB) was used to conduct simulation experiments. These simulations validate the use of the proposed model for short-term predictions. Results show that the NARX neural network notably outperformed the other …

Calderón Preconditioned Pmchwt Equations For Analyzing Penetrable Objects In Layered Medium, Yongpin P. Chen, Lijun Jiang, Sheng Sun, Weng Cho Chew, Jun Hu

Electrical and Computer Engineering Faculty Research & Creative Works

We study Calderón preconditioners for analyzing electromagnetic scattering by penetrable objects in a layered medium. To account for the scattering effects of the multilayered background, the layered medium Green's function is adopted in the Poggio-Miller-Chang-Harrington-Wu-Tsai (PMCHWT) method. However, similar to the free-space case, the spectrum of the resulting equation is undesirable. This leads to a slow convergence of an iterative solver, especially when the geometry is densely meshed. To improve the convergence, a highly effective preconditioner is proposed. Different from its free-space counterpart, the preconditioning operator is constructed based on the Calderón identities for inhomogeneous medium. To reduce the relatively …

Runtime Self-Calibrated Temperature-Stress Cosensor For 3-D Integrated Circuits, Chun Zhang, Dian Ma, Changzhi Li, Yiyu Shi

Electrical and Computer Engineering Faculty Research & Creative Works

On-chip temperature and stress sensors are important for runtime system management techniques tackling thermomechanical reliability issues in 3-D integrated circuits (ICs). However, traditional temperature and stress sensor designs require large calibration overhead to improve accuracy, which incurs significant cost for massive production. To address the challenge, in this paper, we propose a novel temperature-stress cosensor design for 3-D ICs. By exploring the inherent reciprocity of temperature and stress mechanisms, it achieves runtime self-calibration such that no dedicated calibration effort is needed. Simulation results show that the cosensor achieves 0.26 C and 0.43 MPa accuracy on average in temperature and stress …

Shaping The Axial-Ratio Footprint Of Crossed-Dipole Antennas, Adam Narbudowicz, Max Ammann, Janusz Przewocki

Conference papers

A method is proposed to adaptively change the axial-ratio beam of simple circularly-polarized antennas. It is shown, that by varying the phase shift between two orthogonal elements the axial-ratio beam shape can be dynamically adjusted. This allows control of the direction of minimum axial-ratio and the ability to increase or decrease the beamwidth in one of two planes. The method is intended for satellite navigation systems: it can improve the rejection of reflected signals in varying propagation conditions (e.g. urban canyons), while using simple and low-cost circularly-polarized antennas.

Localization Of Near-Field Radio Controlled Unintended Emitting Sources In The Presence Of Multipath Fading, Nurbanu Guzey, Hao Xu, Sarangapani Jagannathan

Electrical and Computer Engineering Faculty Research & Creative Works

Localization of near-field unintended emitting radio controlled (RC) devices under a multipath environment is considered in this paper using a uniform linear array (ULA). Since received signals are dependent on both angle of arrival (AoA) and distance from the RC devices to the ULA in the near-field scenario, traditional localization schemes based on received signal strength indicator, time difference in arrival, which only estimate either AoA or distance, are unsuitable. Therefore, a novel smooth 2-D multiple signal classification (MUSIC) near-field localization scheme is developed to locate RC devices under a multipath environment with a possible location error of 0.5 m. …

Extending The Sensing Of Online Social Networks – A Healthcare Perspective, Asma’ Wasfi Fayez Mustafa

Theses

Obesity is a rising health concern in the United Arab Emirates. Obesity leads to health risks such as diabetes, heart disease, and other conditions. It may also lead to eating disorders, depression, and low self-esteem. Regular exercising helps to protect from obesity, diabetes, heart disease, high blood pressure and better manage stress. Despite all the benefits of exercising, people are doing less of it. In this research, an effort is made to encourage people to exercise by extending the prevalent sensing abilities of Online Social Networks (OSNs). Sensors are used to collect and generate data to be processed, clustered and …

Designing A Bayer Filter With Smooth Hue Transition Interpolation Using The Xilinx System Generator, Zhiqiang Li, Peter Revesz

School of Computing: Conference and Workshop Papers

This paper describes the design of a Bayer filter with smooth hue transition using the System Generator for DSP. We describe and compare experimentally two different designs, one based on a MATLAB implementation and the other based on a modification of the Bayer filter using bilinear interpolation.

A Game-Theoretic Analysis Of The Nuclear Non-Proliferation Treaty, Peter Revesz

School of Computing: Conference and Workshop Papers

Although nuclear non-proliferation is an almost universal human desire, in practice, the negotiated treaties appear unable to prevent the steady growth of the number of states that have nuclear weapons. We propose a computational model for understanding the complex issues behind nuclear arms negotiations, the motivations of various states to enter a nuclear weapons program and the ways to diffuse crisis situations.

Estimating The Flight Path Of Moving Objects Based On Acceleration Data, Peter Revesz

School of Computing: Conference and Workshop Papers

Inertial navigation is the problem of estimating the flight path of a moving object based on only acceleration measurements. This paper describes and compares two approaches for inertial navigation. Both approaches estimate the flight path of the moving object using cubic spline interpolation, but they find the coefficients of the cubic spline pieces by different methods. The first approach uses a tridiagonal matrix, while the second approach uses recurrence equations. They also require different boundary conditions. While both approaches work in O(n) time where n is the number of given acceleration measurements, the recurrence equation-based method can be easier updated …

A Solid-State Ion Detector For Use In Portable Mass Spectrometry, Sadek Salman Sabbah

Theses and Dissertations

Mass spectrometry has long been used as a scientific tool in a wide variety of applications. A portable mass spectrometer would make many of these applications faster and more efficient. One of the key components of a mass spectrometer is its ion detection system; to make a mass spectrometer portable, this system must be small and involve as few components as possible. Single ion detection has been achieved through several methods, nearly all of which are well-known and understood. These methods, however, often require bulky vacuum and/or cooling systems in order to achieve high sensitivity. An ion detection system that …

Geoacoustic Inversion Of Ship Radiated Noise In Shallow Water Using Data From A Single Hydrophone, Steven E. Crocker, Peter L. Nielsen, James H. Miller, Martin Siderius

Electrical and Computer Engineering Faculty Publications and Presentations

The Centre for Maritime Research and Experimentation conducted a geoacoustic inverse experiment in the Mediterranean Sea in the summer of 2012. Among the objectives was to employ an autono- mous underwater vehicle to collect acoustic data to invert for properties of the seafloor. Inversion results for the compression wave speed in the bottom and the source spectrum of the R/V Alliance during a close approach to the bottom moored vehicle are presented. The estimated wave speed was 1529 m/s (r ¼ 10). The source spectrum of the Alliance was estimated across more than six octaves of frequency.

Unconventional Computing Catechism, Christof Teuscher

Electrical and Computer Engineering Faculty Publications and Presentations

What makes a new paradigm or technology promising? What should science, research, and industry invest money in? Is there a life after CMOS electronics? And will the vacuum tube be back? While one cannot predict the future, one can still learn from the past. Over the last decade, unconventional computing developed into a major new research area with the goal to look beyond existing paradigms. In this Perspective, we reflect on the current state of the field and propose a set of questions that anyone working in unconventional computing should be able to answer in order to assess the potential …

Uv Laser-Assisted Diamond Deposition, Mengxiao Wang

Department of Electrical and Computer Engineering: Dissertations, Theses, and Student Research

Diamond, due to its unique properties, has been studied for decades. Many diamond synthesis methods have been developed as well. As one of the synthesis methods, combustion flame chemical vapor deposition (CVD) is considered as the most flexible way. Combined with laser irradiation, laser-assisted combustion flame CVD can enhance the deposition process of diamond films. In this thesis work, efforts were made to explore the capability of a laser-assisted combustion flame CVD technique with krypton fluoride (KrF) excimer laser irradiation for improving diamond thin film quality and deposition rate. The research efforts mainly focus on following activities, including: 1) studying …

A Microfluidic Device For Thermal Particle Detection, Ashwin Kumar Vutha, Benyamin Davaji, Chung-Hoon Lee, Glenn M. Walker

Electrical and Computer Engineering Faculty Research and Publications

We demonstrate the use of heat to count microscopic particles. A thermal particle detector (TPD) was fabricated by combining a 500-nm-thick silicon nitride membrane containing a thin-film resistive temperature detector with a silicone elastomer microchannel. Particles with diameters of 90 and 200 μm created relative temperature changes of 0.11 and −0.44 K, respectively, as they flowed by the sensor. A first-order lumped thermal model was developed to predict the temperature changes. Multiple particles were counted in series to demonstrate the utility of the TPD as a particle counter.

Fabrication And Characterization Of Magnetic Nanostructures, Kevin Scott

USF Tampa Graduate Theses and Dissertations

Magnetic permalloy nanostructures were fabricated onto a silicon wafer using electron beam lithography and a liftoff process. The lithography was performed with a Hitachi SU-70 SEM retrofitted with a Nabity NPGS lithography conversion kit. PMMA of 950kDa molecular weight was used as the photoresist. Features were either nanowires, nanodots, or elliptical or rectangular nanostructures. The nanowires had dimensions of 15µm x 200nm x 40nm, the nanodots had diameters of 145nm and thickness of 12nm, and the ellipses and rectangles had dimensions of 110nm x 50nm x 13nm. Characterization of the nanostructures was performed using the same Hitachi SEM as well …

Age And Gender Recognition For Speech Applications Based On Support Vector Machines, Hasan Erokyar

USF Tampa Graduate Theses and Dissertations

Automatic age and gender recognition for speech applications is very important for a number of reasons. One of the reasons is that it can improve human-machine interaction. For example, the advertisements can be specialized based on the age and the gender of the person on the phone. It also can help identify suspects in criminal cases or at least it can minimize the number of suspects. Some other uses of this system can be applied for adaptation of waiting queue music where a different type of music can be played according to the person's age and gender. And also using …

Control Of A Fuel Cell Based Autonomous Electric Power System For An Aerospace Vehicle, Roshini S. Ashok

Von Braun Symposium Student Posters

No abstract provided.

Telecommunication Network Survivability For Improved Reliability In Smart Power Grids, Sankalp Mogla

USF Tampa Graduate Theses and Dissertations

Power transmission grid infrastructures deliver electricity across large distance and are vital to the functioning of modern society. Increasingly these setups embody highly-coupled cyber-physical systems where advanced telecommunications networks are used to send status and control information to operate power transmission grid components, i.e., "smart grids". However, due to the high inter-dependency between the communication and power grid network layers, failure events can lead to further loss of control of key grid components, i.e., even if they are undamaged. In turn, such dependencies can exacerbate cascading failures and lead to larger electricity blackouts, particularly under disaster conditions. As a result, …