Electrical and Electronics Commons^™

Coupling Into Waveguide Evanescent Modes With Applications In Electron Paramagnetic Resonance, Jason Walter Sidabras

Master's Theses (2009 -)

The use of analytical and numerical techniques in solving the coupling of evanescent modes in a microwave waveguide through slots can be optimized to create a uniform magnetic field excitation on axis within a waveguide. This work has direct applications in Electron Paramagnetic Resonance (EPR) where a 100~kHz time-varying magnetic field is incident on a sample contained in a microwave cavity. Typical cavity designs do not take into consideration the uniformity of the 100~kHz field modulation and assume it to be uniform enough over the sample region from quasi-static principles. This work shows otherwise and uses Ansoft (Pittsburgh, PA) High …

A Voip Implementation On An Embedded Platform, Zachary D. Lund

Master's Theses (2009 -)

This thesis presents a method of building an open VoIP telephone using off-the-shelf hardware. VoIP has become an important area of study in computer science and engineering, but many of the pieces are expensive and proprietary. We discuss the process of building an open IP telephone, the design decisions and difficulties, a performance evaluation of the different pieces of the system, and methods and suggestions for improving the overall system.

The IP telephone is built on the Freescale 68HC12 microcontroller because of its analog and digital capabilities and the Linksys WRT54GL router for its embedded simplicity and network capabilities. The …

Electric Field Computation Of Wet Insulating Surfaces, Bhargavi Sarang

Electrical & Computer Engineering Theses & Dissertations

High voltage outdoor insulators form the backbone of modem power systems and therefore play a pivotal role in reliable supply of power. The presence of water droplets/films due to rain, fog, etc. enhances the electric field intensity and leads to electrical breakdown subsequently affecting the longevity of the insulator. The magnitude of surface E-fields necessary for initiation of electrical breakdown is a function of water repellent characteristic of an insulator called hydrophobicity. Thus, knowledge of field distribution around water droplets/films at various hydrophobic levels is significant in designing a better insulating material.

The current research analyzed electric field distributions on …

Ontology-Based Automatic Classification For News Articles In Indonesian Language, Prajna Wira Basnur, Dana Indra Sensuse

Makara Journal of Technology

Ontology-Based Automatic Classification for News Articles in Indonesian Language. Searching specific information will be difficult if relying only on query. Choosing less specific queries will result in a lot of irrelevant information fetched by the system. One of the most successful ways to overcome this problem is to perform document classification based on the topic. There are many methods that can be used to conduct such a classification, such as using statistical and machine learning approaches. However, those document classification methods require training the data or learning the documents. In this study, the authors attempted to classify documents using a …

Particle Filter With Binary Gaussian Weighting And Support Vector Machine For Human Pose Interpretation, Indah Agustien, Muhammad Rahmat Widyanto, Sukmawati Nur Endah, Tarzan Basaruddin

Makara Journal of Technology

This paper proposes human pose interpretation using particle filter (PF) with Binary Gaussian Weighting and support vector machine (SVM). In the proposed system, particle filter is used to track a human object, then this human object is skeletonized using thinning algorithm and classified using SVM. The classification is to identify human pose, whether it is normal or abnormal behavior. Here particle filter is modified through weight calculation using Gaussian distribution to reduce the computational time. The modified particle filter consists of four main phases. First, particles are generated to predict target’s location. Second, the weight of certain particles is calculated …

Maintenance Activity Planning By Reability Centered Maintenance Ii Method, Rachmad Hidayat, Nachnul Ansori, Ali Imron

Makara Journal of Technology

Maintenance Activity Planning by Reability Centered Maintenance II Method. This research discusses maintenance activity planning using the RCM II method to evaluate failure function risk on compresor screw. The calculation of maintenance time is performed by considering maintenance and repair costs. The risk evaluation result with RPN shows that the critical component that needs to get the main priority in applying maintenance on compresor screw is function disorder on timeworn piston and on the broken outgoing air sponge’s filter that receives RPN 45. The optimum maintenance time calculation is applied on components that undergo scheduled restoration and scheduled discard task …

Software Design Of Mobile Antenna For Auto Satellite Tracking Using Modem Correction And Elevation Azimuth Method, Djamhari Sirat, Muhamad Asvial, Arman Djohan Diponegoro, Himawan Sidharta

Makara Journal of Technology

Software Design of Mobile Antenna for Auto Satellite Tracking Using Modem Correction and Elevation Azimuth Method. Pointing accuracy is important in satellite communication. Because the satellite’s distance to the surface of the earth's satellite is so huge, 1 degree of pointing error will make the antenna unable to send data to satellites. To overcome this, the auto-tracking satellite controller is made. This system uses a microcontroller as the controller, with the GPS as the location indicator of the antenna, a digital compass as the beginning of antenna pointing direction, a rotary encoder as azimuth and elevation censor, and a modem …

Petroleum Degradation In Soil By Thermophilic Bacteria With Biopile Reactor, Astri Nugroho, Edison Effendi, Yulius Karonta

Makara Journal of Technology

Crude oil degradation has been carried out using biopile reactor in total petroleum hydrocarbon (TPH) concentration of 5%, 10% and 15%. The thermophilic microorganisms used from isolation result and identification are Aeromonas salmonicida, Bacillus pantothenticus, and Stenotrophomonas maltophilia. The biodegradation of biopile reactor is done by various concentrations of TPH, total plate count (TPC), and volatile suspended solid (VSS) per day for 30 days. The biodegradation of kinetic parameter calculated consists of μ, μm, Y, Yt, Yobs, Kd, Ks from TPH concentration decision, and TPC and VSS in every microorganism with t (observation time) of 0 hour to 168 hours. …

Ergonomic Analysis Of Ui’S Bicyclesusing Posture Evaluation Index (Pei) Method In Virtual Environment, Erlinda Muslim, Boy Nurtjahyo, Zulkarnain Zulkarnain, Liza Afrinotha

Makara Journal of Technology

Ergonomic Analysis of UI’s Bicycles Using Posture Evaluation Index (PEI) Method in Virtual Environment. This research was conducted to study the ergonomic aspect of University of Indonesia’s bicycles in virtual environment. Software Jack 6.0 was used to analyze it. PEI was used as an approach that integrated the results of three methods: lower back analysis (LBA), ovako working posture analysis (OWAS), and rapid upper limb assessment (RULA). The research objective is to evaluate the existing design of University of Indonesia’s bicycles and to determine the most ergonomic redesign which concerns handlebar height and saddle height modification. The result showed that …

Power Quality In Grid Connected Renewable Energy Systems: Role Of Custom Power Devices, Shafiuzzaman Khan Khadem, Malabika Basu, Michael Conlon

Conference papers

This paper deals with the technical review of power quality problems associated with the renewable based distributed generation systems and how the custom power devices like STATCOM, DVR and UPQC play important role in power quality improvement. IEEE and IEC standard for the grid connected renewable energy systems are one of the critical point of interest for the selection of custom power devices. Special attention has been given on the compensation of reactive power, harmonic current and voltage fluctuation during the interconnected as well as islanding mode of operation. As the solar and wind are the most abundant resources therefore …

The Control Of Rotor Side And Grid Side Converters In A Dfig During Network Voltage Unbalance Conditions Using Resonant Current Controllers., Joseph Kearney, Michael Conlon, Eugene Coyle

Conference papers

This paper implements control techniques to enable improved operation of DFIG’s when subjected to the effects of network voltage unbalance conditions. The control scheme involves the integration of a resonant regulator into the PI controllers of both the rotor side and grid side converters in a DFIG. The resonant controller is tuned to twice the network frequency (2ω_e) and designed to mitigate against the oscillations in a DFIG due to network voltage unbalance conditions. The grid side converter controller also incorporates a second resonant controller tuned to three times the grid frequency (3ω_e) to alleviate the …

Spectral Domain Rf Fingerprinting For 802.11 Wireless Devices, Sheldon A. Munns

Theses and Dissertations

The increase in availability and reduction in cost of commercial communication devices (e.g. IEEE compliant such as 802.11, WiFi, 802.16, Bluetooth etc.) has increased wireless user exposure and the need for techniques to properly identify/classify signals for increased security measures. Communication device emissions include intentional modulation that enables correct device operation. Hardware and environmental factors alter the ideal response and induce unintentional modulation effects. If these effects (features) are sufficiently unique, it becomes possible to identify a device using its fingerprint, with potential discrimination of not only the manufacturer but possibly the serial number for a given manufacturer. Many techniques …

Pulse Shape Correlation For Laser Detection And Ranging (Ladar), Brian T. Deas

Theses and Dissertations

Radar systems provide an important remote sensing capability, and are crucial to the layered sensing vision; a concept of operation that aims to apply the right number of the right types of sensors, in the right places, at the right times for superior battle space situational awareness. The layered sensing vision poses a range of technical challenges, including radar, that are yet to be addressed. To address the radar-specific design challenges, the research community responded with waveform diversity; a relatively new field of study which aims reduce the cost of remote sensing while improving performance. Early work suggests that the …

Toward A Mobile Agent Relay Network, Hyon H. Kwak

Theses and Dissertations

Although wireless communication provides connectivity where hardwired links are difficult or impractical, it is still hindered by the environmental conditions where the communicators reside. Signal loss over large distances or because of intervening obstacles can be mitigated by increasing the user's transmission power or adding repeater nodes between the users. Unfortunately, increasing the signal strength strains limited power resources and increases the likelihood of eavesdropping. Stationary repeaters are impractical for highly mobile users in dangerous environments. While mobile relay nodes might be a preferred solution, a centralized control scheme saps bandwidth from important traffic and introduces a single point of …

Improved Multispectral Skin Detection And Its Application To Search Space Reduction For Dismount Detection Based On Histograms Of Oriented Gradients, Adam L. Brooks

Theses and Dissertations

Due to the general shift from conventional warfare to terrorism and urban warfare by enemies of the United States in the late 20th Century, locating and tracking individuals of interest have become critically important. Dismount detection and tracking are vital to provide security and intelligence in both combat and homeland defense scenarios including base defense, combat search and rescue (CSAR), and border patrol. This thesis focuses on exploiting recent advances in skin detection research to reliably detect dismounts in a scene. To this end, a signal-plus-noise model is developed to map modeled skin spectra to the imaging response of an …

Monocular Passive Ranging By An Optical System With Band Pass Filtering, Joel R. Anderson

Theses and Dissertations

An instrument for monocular passive ranging based on atmospheric oxygen absorption near 762 nm has been designed, built and deployed to track emissive targets, including the plumes from jet engines or rockets. An intensified CCD array is coupled to variable band pass liquid crystal display filter and 3.5 – 8.8 degree field of view optics to observe the target. By recording sequential images at 7 Hz in three 6 nm width bands, the transmittance of the R-branch of the O₂ (X-b) (0,0) band is determined. A metric curve for determining range from transmittance is developed using the HITRAN spectral …

Optical Properties Of Si, Ge, Gaas, Gasb, Inas, And Inp At Elevated Temperatures, Thomas R. Harris

Theses and Dissertations

Investigation of the optical and electrical behavior of some semiconductors at very high temperatures has not been an area of much study, at least not experimentally. The importance of such research becomes obvious due to the effects of high temperatures on semiconductor devices such as infrared detectors and light emitters. Besides the destructive effects of thermal stress and melting, changes in the optical properties of the material can greatly affect device performance. In this research, the infrared absorption of Si, Ge, GaAs, GaSb, InAs, and InP was measured from 0.6 to 25 μm at temperatures ranging from 295 up to …

Flexible Computing Architecture For Real Time Skin Detection, Matthew P. Hornung

Theses and Dissertations

In both the Air Force and Search and Rescue Communities, there is a current need to detect and characterize persons. Existing methods use red-green-blue (RGB) imagery, but produce high false alarm rates. New technology in multi-spectral skin detection is better than the existing RGB methods, but lacks a control and processing architecture to make them efficient for real time problems. We hypothesize that taking a minimalistic approach to the software design, we can perform image preprocessing, feature computation, and skin detection in real time. A number of applications require accurate detection and characterization of persons, human measurement and signature intelligence …

Frequency Diverse Array Radar: Signal Characterization And Measurement Accuracy, Steven H. Brady

Theses and Dissertations

Radar systems provide an important remote sensing capability, and are crucial to the layered sensing vision; a concept of operation that aims to apply the right number of the right types of sensors, in the right places, at the right times for superior battle space situational awareness. The layered sensing vision poses a range of technical challenges, including radar, that are yet to be addressed. To address the radar-specific design challenges, the research community responded with waveform diversity; a relatively new field of study which aims reduce the cost of remote sensing while improving performance. Early work suggests that the …

Characterization And Measurement Of Passive And Active Metamaterial Devices, Christopher A. Lundell

Theses and Dissertations

This document addresses two major obstacles facing metamaterial development: uncertainty in the characterization of electromagnetic field behavior in metamaterial structures and the relatively small operational bandwidth of metamaterial structures. To address the first obstacle, a new method to characterize electromagnetic field behavior in a metamaterial is presented. This new method is a bistatic radar cross section (RCS) measurement technique. RCS measurements are well-suited to measuring bulk metamaterial samples because they show frequency dependence of scattering angles and offer common postprocessing techniques that can be useful for visualizing results. To address the second obstacle, this document characterizes the effectiveness of an …

Artificial Inhomogeneous Tapered Impedance Sheet Characterization And Applications, Jeffrey P. Massman

Theses and Dissertations

The ability to manipulate a complex impedance sheet about a PEC or general dielectric cylinder of arbitrary diameter to control the overall scattering characteristics at particular angles for shielding or scattering applications is presented. It is shown that with the capability to readily control both the real and imaginary components of a percolated lossy film's effective impedance, specific impedance distributions can be obtained to effectively direct the overall nulls in the bistatic scattering pattern. The exact approach only requires negligible truncation error of the matrix solution and can be applied to cylinders of arbitrary size. This approach relies on general …

Low-Complexity Transmit Diversity Scheme Using Moderate-Sized Signal Constellations, B. K. Khoo, P. Xiao, S. Y. Le Goff, B. S. Sharif, C. C. Tsimenidis

Electrical & Electronic Engineering

In the conventional space-time coding technique [1], nT radio frequency (RF) chains are employed to transmit signals simultaneously from nT transmit antennas. In this Letter, a lowcomplexity transmit diversity scheme with nT = 2 transmit antennas is proposed. The proposed system employs only one RF chain as well as a low-complexity switch for transmission.

Novel Ac Side P&O Maximum Power Transfer Control For Grid Connected Photovoltaic Systems, Mohamed Moin Hanif, Malabika Basu, Kevin Gaughan

Conference papers

Grid connected Photovoltaic inverters can convert PV energy into electricity with very high efficiencies. Power from the PV panels fluctuates depending on various weather conditions. PV inverters usually include a maximum power point tracker (MPPT) to track this varying power, in order to transfer all the available power to the grid efficiently. Control of power transferred to the grid along with the MPPT plays a crucial role in determining the efficiency of a PV system. This paper discusses about the basic power transfer theory between sources (PV and Grid) and focuses on the need of a DC-DC boost circuit, along …

Target Localization In Mimo Radar Systems, Hana Godrich

Dissertations

MIMO (Multiple-Input Multiple-Output) radar systems employ multiple antennas to transmit multiple waveforms and engage in joint processing of the received echoes from the target. MIMO radar has been receiving increasing attention in recent years from researchers, practitioners, and funding agencies. Elements of MIMO radar have the ability to transmit diverse waveforms ranging from independent to fully correlated. MIMO radar offers a new paradigm for signal processing research. In this dissertation, target localization accuracy performance, attainable by the use of MIMO radar systems, configured with multiple transmit and receive sensors, widely distributed over an area, are studied. The Cramer-Rao lower bound …

Service Oriented Networking For Multimedia Applications In Broadband Wireless Networks, Ehsan Haghani Dogaheh

Dissertations

Extensive efforts have been focused on deploying broadband wireless networks. Providing mobile users with high speed network connectivity will let them run various multimedia applications on their wireless devices. In order to successfully deploy and operate broadband wireless networks, it is crucial to design efficient methods for supporting various services and applications in broadband wireless networks. Moreover, the existing "access-oriented" networking solutions are not able to fully address all the issues of supporting various applications with different quality of service requirements. Thus, "service-oriented" networking has been recently proposed and has gained much attention.

This dissertation discusses the challenges and possible …

Cooperative Retransmission Protocols In Fading Channels : Issues, Solutions And Applications, Igor Stanojev

Dissertations

Future wireless systems are expected to extensively rely on cooperation between terminals, mimicking MIMO scenarios when terminal dimensions limit implementation of multiple antenna technology. On this line, cooperative retransmission protocols are considered as particularly promising technology due to their opportunistic and flexible exploitation of both spatial and time diversity. In this dissertation, some of the major issues that hinder the practical implementation of this technology are identified and pertaining solutions are proposed and analyzed. Potentials of cooperative and cooperative retransmission protocols for a practical implementation of dynamic spectrum access paradigm are also recognized and investigated. Detailed contributions follow.

While conventionally …

Adaptive Trust And Reputation System As A Security Service In Group Communications, Pitipatana Sakarindr

Dissertations

Group communications has been facilitating many emerging applications which require packet delivery from one or more sender(s) to multiple receivers. Owing to the multicasting and broadcasting nature, group communications are susceptible to various kinds of attacks. Though a number of proposals have been reported to secure group communications, provisioning security in group communications remains a critical and challenging issue.

This work first presents a survey on recent advances in security requirements and services in group communications in wireless and wired networks, and discusses challenges in designing secure group communications in these networks. Effective security services to secure group communications are …

Generalized Discrete Fourier Transform With Non-Linear Phase : Theory And Design, Handan Agirman-Tosun

Dissertations

Constant modulus transforms like discrete Fourier transform (DFT), Walsh transform, and Gold codes have been successfully used over several decades in various engineering applications, including discrete multi-tone (DMT), orthogonal frequency division multiplexing (OFDM) and code division multiple access (CDMA) communications systems. Among these popular transforms, DFT is a linear phase transform and widely used in multicarrier communications due to its performance and fast algorithms. In this thesis, a theoretical framework for Generalized DFT (GDFT) with nonlinear phase exploiting the phase space is developed. It is shown that GDFT offers sizable correlation improvements over DFT, Walsh, and Gold codes. Brute force …

Advanced Classification Of Ofdm And Mimo Signals With Enhanced Second Order Cyclostationarity Detection, Miao Shi

Dissertations

With the emergence of cognitive radio and the introduction of new modulation techniques such as OFDM and MIMO, the problem of Modulation Classification (MC) becomes more challenging and complicated. In the first part of the thesis, we explore the automatic modulation classification to blindly distinguish OFDM from single carrier signals. We use the fourth order cumulants; an approach which in the past has been also applied to classify single carrier signals. A blind OFDM parameter estimation scheme was then followed, which includes the estimation of number of subcarriers, CP length, timing and frequency offset and the oversampling factor for the …

A Fpga/Dsp Design For Real-Time Fracture Detection Using Low Transient Pulse, Akash Mathur

Theses

This work presents the hardware and software architecture for the detection of fractures and edges in materials. While the detection method is based on the novel concept of Low Transient Pulse (LTP), the overall system implementation is based on two digital microelectronics technologies widely used for signal processing: Digital Signal Processor (DSP) and Field Programmable Gate Array (FPGA). Under the proposed architecture, the DSP carries out the analysis of the received baseband signal at a lower rate and hence can be used for large number of signal channels. The FPGA's master clock runs at a higher frequency (62.5MHz) for the …