Electrical and Computer Engineering Commons^™

Secure Degrees Of Freedom For The Mimo Wire-Tap Channel With A Multi-Antenna Cooperative Jammer, Mohamed Nafea, Aylin Yener

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a multiple antenna wire-tap channel in the presence of a multi-antenna cooperative jammer is studied. In particular, the secure degrees of freedom (s.d.o.f.) of this channel is established, with $N-{t}$ antennas at the transmitter, $N-{r}$ antennas at the legitimate receiver, and $N-{e}$ antennas at the eavesdropper, for all possible values of the number of antennas, $N-{c}$, at the cooperative jammer. In establishing the result, several different ranges of $N-{c}$ need to be considered separately. The lower and upper bounds for these ranges of $N-{c}$ are derived and are shown to be tight. The achievability techniques developed rely …

Apparatus And Method For Controlling Dc-Ac Power Conversion, Patrick L. Chapman, Brian T. Kuhn, Robert S. Balog, Jonathan W. Kimball, Philip T. Krein, Alexander Gray, T. Esram

Electrical and Computer Engineering Faculty Research & Creative Works

An apparatus and method for controlling the delivery of power from a DC source to an AC grid includes an inverter configured to deliver power from the unipolar input source to the AC grid and an inverter controller. The inverter includes an input converter, an active filter, and an output converter. The inverter controller includes an input converter controller, an active filter controller and an output converter controller. The input converter controller is configured to control a current delivered by the input converter to a galvanically isolated unipolar bus of the inverter. The output converter is configured to control the …

Implementation And Performance Analysis Of Long Term Evolution Using Software Defined Radio, Kedar Bhusal

Electrical Engineering Theses

The overwhelming changes in the field of communication brought about need for high data rates, which led to the development of a system known as Long Term Evolution (LTE). LTE made good use of Orthogonal Frequency Division Multiplexing Access (OFDMA) in its downlink and Single Carrier Frequency Division Multiplexing Access (SCFDMA) in its uplink transmission because of their robust performance. These multiple access techniques are the major focus of study in this thesis, with their implementation in the LTE system.

GNU Radio is a software Defined Radio (SDR) platform. It comprises of C++ signal processing libraries. For user simplicity, it …

Special Issue On Supercapacitors, Xiao-Gang Zhang

Journal of Electrochemistry

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Strategies To Enhance Energy Density For Supercapacitors, Jun-Wei Lang, Xu Zhang, Ru-Tao Wang, Xing-Bin Yan

Journal of Electrochemistry

The biggest advantage of supercapacitor lies in not only the excellent pulse and fast charging-discharging performance, but also the characteristics of long cycle life and wide operating temperature window with no pollution. However, the energy density of supercapacitor is low. In this paper, the working principle, the development status, defects and improvement method of supercapacitors are introduced. Based on the research workes of the supercapacitors with high energy density in our group, combined with the literature reports in recent years, the strategies to promote the energy density of supercarpacitors will be focused. The strategies for the enhancement of energy density …

Porous Carbon Materials Produced By Koh Activation For Supercapacitor Electrodes, Jiang-Lin Ye, Yan-Wu Zhu

Journal of Electrochemistry

Porous carbon materials with high specific surface area and excellent conductivity have wide applications in supercapacitor electrodes. Much effort has been made to synthesize and tailor the microstructures of porous carbon materials via various activation procedures (physical and chemical activations). In particular, the chemical activation using potassium hydroxide (KOH) as an activating reagent is promising because of the well-defined micropore size distribution and ultrahigh specific surface area up to 3000 m²·g^-1 of the resulting porous carbons. Based mainly on the previous works taken by the authors and collaborators in the field, we have summarized the activation mechanism …

Recent Advances On Carbon And Transition Metallic Compound Electrodes For High-Performance Supercapacitors, Dun Lin, Xi-Yue Zhang, Yin-Xiang Zeng, Ming-Hao Yu, Xi-Hong Lu, Ye-Xiang Tong

Journal of Electrochemistry

Supercapacitors (SCs) have stimulated intensive interests for their promising applications in electric vehicles and portable electronics, etc. Electrode material is the most important key component of SCs, which vastly determines the performance of SCs. Carbon and transition metallic compound materials have attracted considerable attention and been widely explored as electrode materials. However, the insufficient capacitance of carbon materials and unsatisfactory conductivity and cyclic stability of transition metallic compounds severely limit their implementation as robust SC electrodes. Herein, we highlight our recent efforts to boost the capacitive performance of carbon and metal oxide/nitride electrodes by rationally structural and componential design. The …

Lithium Ion Hybrid Capacitor With High Energy Density, Xian-Zhong Sun, Xiong Zhang, Kai Wang, Yan-Wei Ma

Journal of Electrochemistry

Lithium ion hybrid capacitors are electrochemical energy storage devices combining the advantages of both Li-ion battery and electrochemical capacitor. They can be extensively used in many fields. However, the commercialization of lithium ion hybrid capacitor has been encountered several problems, e.g., the device structure design, the screening of materials, the pre-lithiation process, and the interface between electrolyte and electrode, etc. This review summarizes the recent research advances in lithium ion hybrid capacitor with high energy density, including the selection of the active materials in cathode/anode and the separator, the pre-lithiation method using the three-electrode structure, the high- and low-temperature performances, …

Template Induced Fabrication Of Nitrogen Doped Carbon Sheets As Electrode Materials In Supercapacitors, Tao Huang, Guang-Zhi Tao, Chong-Qing Yang, Deng Lu, Lie Ma, Dong-Qing Wu

Journal of Electrochemistry

Due to the good electrical conductivity, high specific surface area, and excellent chemical/mechanical stability, carbon nanomaterials with two-dimensional morphology have gradually become the hot topic of the research on supercapacitors. Herein, we report for the first time the fabrication of nitrogen doped carbon sheets (NCSs). In our approach, the sheet-like magnisum aluminum (MgAl) layered double hydroxide was used as the hard template, which was mixed with o-phenylene diamine and iron chloride. The following thermal treatment could render the polymerization and carbonization of o-phenylene diamine. The NCSs with ordered hexagonal architectures were formed by final etching process of the thermally treated …

Preparation And Characterization Of Cellulose Acetate-Based Separator For Lithium-Ion Batteries, Hua-Feng Luo, Yuan-Dong Qiao

Journal of Electrochemistry

To improve the electrolyte wettability and thermal resistance of separators used for lithium-ion battery, a novel cellulose acetate (CA)-based separator is facilely prepared by non-solvent induced phase separation (NIPS) wet-process and investigated in lithium-ion batteries. Systematical investigations including morphological characterization, electrolyte wettability and thermal resistance testing were carried out. The results demonstrated that the CA-based separator exhibited well developed three-dimensional porous structures with porosity up to 65%, which is 1.5 times higher than that of PE separator. The CA separator also showed excellent electrolyte uptake (285%) and thermal stability at 150 ^oC for 30 min. Compared with the commercial …

Smart Inverter Control And Operation For Distributed Energy Resources, Ahmad F. Tazay

USF Tampa Graduate Theses and Dissertations

The motivation of this research is to carry out the control and operation of smart inverters and voltage source converters (VSC) for distributed energy resources (DERs) such as photovoltaic (PV), battery, and plug-in hybrid electric vehicles (PHEV). The main contribution of the research includes solving a couple of issues for smart grids by controlling and implementing multifunctions of VSC and smart inverter as well as improving the operational scheme of the microgrid. The work is mainly focused on controlling and operating of smart inverter since it promises a new technology for the future microgrid. Two major applications of the smart …

Measurement Of Speed Of Sound Profile Using Laaces Balloon, Zhuang Li, Brett Schaefer, Brian Schaefer, William Dever, Tyler Morgan, Matthew Foltz

2017 Academic High Altitude Conference

The goal of this mission is to test the speed of sound at different altitudes and ultimately at a maximum height of 100,000 feet (30 km). In conjunction with this testing, environmental parameters including temperature, pressure, and humidity are measured and used to calculate the speed of sound to compare to the measured results. The team constructed the payload “Dorothy” using polystyrene foam due to its lightweight and thermal isolation property. An ultrasonic sensor with a reflection mirror were installed outside payload box to measure speed of sound. All the sensors were calibrated. Software for the project was developed in …

How Iridium Satellite Tracker Model 9602-Lp Asset Affects Span Of Control In High Altitidue Balloning, Steven Hamby

2017 Academic High Altitude Conference

The Irdium Satelitte Network has greatly increased safety in the ballooning field by enabling a greater span of control in flight awarness and termination. This enhanced awareness stems from accurate high interval GPS coordinates that can be integrated into ground station tracking software. The Iridium Network creates the ability to send activation commands remotely with high reliabilty using emails. Additionally this feature has the ability to use local rf transmiters and recievers to increase the flexibilty of cutdown designs. The Iridium Modems provides significant coverage regardless of altitude and loss of ground communication. It is marketed at econmical price point …

Multiple Camera Control Using An Octaplexer In A 5.8 Ghz Video System, Uciel Garcia Olmedo, Skylar Tamke

2017 Academic High Altitude Conference

One of the greatest challenges with camera systems on High-Altitude Balloons (HAB) is to control the direction that they point. This is because the payload boxes constantly rotate during the flight. While mechanical gambles are normally used, an electronic gambled was designed using multiple cameras and a series of multiplexers. The design consists of 8 version 1 pi cameras, connected through a series of multiplexers and interfacing with an IMU to tell the direction the cameras are facing. This design attaches to the Raspberry Pi through the GPIO pins. The multiplexers turn on the camera facing the orientation desired and …

Ground Station Tracking System, Garret Hilton, Carter Mciver, Steven Hamby, Trevor Gahl, Casey Coffman, David Schwehr

2017 Academic High Altitude Conference

One of the Eclipse Ballooning Project’s main goals was to stream live video of the eclipse to the internet. To accomplish this task a tracking antenna was built to follow the balloon payload. As an added challenge, the task had to be completed on a budget. The “ground station” is the center for communication between the payload and user. This system utilizes GPS position reports from the payload via the iridium network to determine the balloons position. The computer algorithm takes in additional GPS and IMU data from the ground station to determine a relative heading to orientate the antenna …

2017 Eclipse Rfd-900 Still Image System, Tristan Running Crane, Uciel Garcia Olmedo, David Schwehr

2017 Academic High Altitude Conference

As part of the NASA Space Grant 2017 Eclipse Ballooning Project, Montana Space Grant Consortium designed a camera system capable of transmitting still images from a balloon borne payload to a remote ground station via a RFD-900 radio. This payload consists of a Raspberry Pi, a Raspberry Pi camera, custom power supply and a RFD 900MHz radio. This system was designed to record pictures at high and low resolution at altitude. The low resolution images could be selected for downlinking back to the ground via the radio, while the high resolution pictures were saved to the Raspberry Pi memory card. …

University Of Maine High Altitude Ballooning Eclipse Experience, Kent Seneres, Derek Haas, William Bessette, Richard Eason

2017 Academic High Altitude Conference

The University of Maine High Altitude Ballooning (UMHAB) team launched two balloons during the August 21, 2017 total solar eclipse, producing a consistent online video stream of the eclipse to an altitude of 110,000 feet. This paper discusses the key factors that lead to a successful launch and recovery, such as thorough testing procedures, redesign of components, choice of launch site, and a touch of luck. In preparation for the event, the team tested the equipment and code over eleven balloon launches. Airplane based testing and land testing were conducted for the tracking and video stream components. The payloads and …

Placing A High-Altitude Balloon In The Path Of Totality, Nicholas Jordan, Christopher Helmerich

2017 Academic High Altitude Conference

The UAH Space Hardware Club had conducted 70 flights prior to the Eclipse. In this time, we have gained valuable skills and experience which we have put into practice and passed on through the years. We put these skills into practice for the Eclipse. Our first challenge was finding where to launch. We started out by looking for suitable locations inside totality. We also examined a map of totality at 80,000 ft. We then ran predictions based on past weather during that time of year. By compiling multiple past predictions, we eliminated possible launch sites. We had multiple payloads, some …

New Approach To Improve The Breakdown Strength For Thick Dielectrics: A Theoretical Study, Sijay Huang, Biswajit Ray

Von Braun Symposium Student Posters

No abstract provided.

Electrostatic Sail - Tether Deployment Testbed, Davis Hunter

Von Braun Symposium Student Posters

No abstract provided.

Characterization Of A Microplasma-Based Heaterless, Insertless Cathode, Ryan Gott, Gabriel Xu

Von Braun Symposium Student Posters

No abstract provided.

Grid-Based Rfid Indoor Localization Using Tag Read Count And Received Signal Strength Measurements, Nanda Gopal Jeevarathnam

USF Tampa Graduate Theses and Dissertations

Passive ultra-high frequency (UHF) radio frequency identification (RFID) systems have gained immense popularity in recent years for their wide-scale industrial applications in inventory tracking and management. In this study, we explore the potential of passive RFID systems for indoor localization by developing a grid-based experimental framework using two standard and easily measurable performance metrics: received signal strength indicator (RSSI) and tag read count (TRC). We create scenarios imitating real life challenges such as placing metal objects and other RFID tags in two different read fields (symmetric and asymmetric) to analyze their impacts on location accuracy. We study the prediction potential …

Development Of 3-Axis Control System For 3u Cubesat, Tyler Sholes, Dean Alhorn, Chandler Ellis, William Hankins, Ian Hines

Von Braun Symposium Student Posters

No abstract provided.

28 Ghz 5g Radio Over Fiber Using Uf-Ofdm With Optical Heterodyning, E Martin, C Browning, L Barry, A Farhang, L Doyle, Manh-Ha Hoang, Matthias John, Max Ammann

Conference Papers

A 5G millimeter-wave radio over fibre optical fronthaul system based on optical heterodyning, utilising an externally injected gain switched distributed feedback laser, is successfully demonstrated. Five bands of UF-OFDM are transmitted over 25 km of fibre and a 28 GHz Vivaldi Antenna wireless link. Transmission performance below the 7% FEC limit is achieved with an aggregate total data rate of 4.56 Gb/s.

Grouping Environmental Factors Influencing Individual Decision-Making Behavior In Software Projects: A Cluster Analysis, Luiz Fernando Capretz

Electrical and Computer Engineering Publications

An individual’s decision-making behavior is heavily influenced by and adapted to external environmental factors. Given that software development is a human-centered activity, individual decision-making behavior may affect the software project quality. Although environmental factors affecting decision-making behavior in software projects have been identified in prior literature, there is not yet an objective and a full taxonomy of these factors. Thus, it is not trivial to manage these complex and diverse factors. To address this deficiency, we first design a semantic similarity algorithm between words by utilizing the synonymy and hypernymy relationships in WordNet. Further, we propose a method to measure …

Inductance And Capacitance, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

• Inductance is dominated by the size of the loop • Current density in conductor is a secondary effect (wire size) • Inductance is the key limiting factor to make current flow • Current always flows in lowest impedance • At low frequencies → lowest resistance • At high frequencies → lowest inductance • Switch from low to high frequency in KHz range • Capacitance is simply how much charge can be stored.

Introduction To The Finite-Difference Time-Domain (Fdtd) Technique, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

No abstract provided.

On Inductance Of Power Islands And Its Impact On Decoupling Behavior In High Speed Boards, Mosin Mondal, Bruce Archambeault

Electrical and Computer Engineering Faculty Research & Creative Works

Design of power delivery networks for printed circuit boards hosting both analog and digital parts often employs small power islands for supplying power to sensitive components. While providing necessary isolation from noise generated by other components, the power islands also experience increased inductance due to current crowding at the bridge. In this paper, the inductance at a port on the power island has been quantified. The variation of port inductance with the bridge width and slot/gap width has been studied. It has been demonstrated that the increased inductance adversely affects the effectiveness of decoupling capacitors. This necessitates more careful design …

Answering Food Insecurity: Serving The Community With Food And Knowledge Using Technology, Courtney Simpson

Purdue Journal of Service-Learning and International Engagement

The courses of Tech120, CGT110, and ENGT 180/181 and Red Gold at Purdue collaborated to design a robot that would plant and water a garden for a local community charter school. The students centered the project on the users’ needs for fresh food, nutrition education, and early exposure to STEM for children. The school, Anderson Preparatory Academy (APA), is comprised of many children who come from low-income families and are in the free or reduced lunch program. Inspired from “Farm Bot,” a similar system that allows for almost hands-free gardening, the “Boiler Bot” is designed to be scalable so children …

The Interval Grey Numbers Ranking Based On Risk Preferences, Zhaobin Li, Zhuo Zhang, Jian Liu, Shuai Zhang

Electrical and Computer Engineering Faculty Research & Creative Works

In this paper, a new method for ranking interval grey numbers to address the challenge in multi-criteria decision-making problems with interval grey numbers has been proposed. This new method involves the risk preferences of decision makers. First, we propose a new method to rank the interval grey numbers by comparing the possibility degree or whitened value. Second, we classify the decision makers into three different types according to their risk preferences then we establish the corresponding risk preference assumptions to solve the problem that different interval grey numbers with the same possibility degree or whitened value. Finally, we use a …