This thesis presents an adaptive modulation scheme using a Walsh-code modulator. The Walsh-code modulator consists of a dynamic demultiplexer and predetermined sets of orthogonal Walsh-Hadamard codes. The demultiplexer can demultiplex the input bit stream into a maximum of thirty-two sub-streams. The Walsh- Hadamard codes are used to spread the spectrum...
In cellular telephones, RF power amplifiers consume a significant part of the total phone current. Reducing the average PA current will extend battery life. In GSM systems the handset is commanded by the base station to transmit at power levels lower than full power much of the time. A Doherty...
The long-term goal of the research project initiated with this thesis is the development of lead-free, fully-transparent ferroelectric devices, such as ferroelectric capacitors or ferroelectric-gate field-effect transistors. Ferroelectric materials exhibit spontaneous polarization with the application of an external electric field, which is persistent upon removal of the applied field, and...
GEM-GIS is a prototype of a web-based GIS/Database application for managing a germplasm collection. This application include a database, a map interface, a set of web forms for database access, and an analysis module. The analysis module perform statistical analysis for the accessions of a species selected by the user...
This study presents the results of using common two or three-parameter "default" distributions in place of "best fit distributions" in simulations of serial production lines with finite buffers and blocking. The default distributions used instead of the best-fit distribution are chosen such that they are non-negative, unbounded, and can match...
Switch-mode power supplies (SMPS's) not only convert energy, they also consume it. Typical operational efficiencies are approximately 25 to 60% for linear power supplies, and approximately 50-90% for switching power supplies. This means that products whose end-use electronics are dc, such as televisions and DVD players, could consume 50% less...
A main arithmetic operation for cryptographic systems is modular exponenti- ation. Exponentiation is computed by a long sequence of modular multiplications. Modular multiplication can be implemented in a general-purpose processor or a dedicated hardware, but dedicated hardware tends to be faster than a processor. Modular multiplication is a time-consuming operation,...
Accreditation Board for Engineering and Technology, Inc. (ABET) is the primary organization responsible for monitoring, evaluating and certifying the quality of engineering, engineering technology, computing and applied sciences education in the United States. In 2000, ABET changed the way computer science (and engineering) programs are accredited from a ‘checklist’ approach...
"A non-redundant number system has the digit set limited ranging from 0 to radix -1. While the Signed digit numbers have digit set consisting of more than radix r values. Hence it is also called redundant number system. Furthermore, the advantage of redundant number system lies in its application for...
In this report, I first introduce three areas of interest to collaborative filtering researchers, namely: (a) how to solve the sparsity and scalability problems in recommendation systems; (b) how to rapidly develop and test collaborative filtering algorithms; and (c) how to apply collaborative filtering to unbounded numeric preference data. In...
Timing attacks enable an attacker to extract secret information from a cryptosystem by observing timing differences with respect to different inputs given to an encryption or decryption algorithm. Werner Schindler has proposed a timing attack on smart card devices. We implemented this attack based on the same approach for RSA...
Personalization is defined as a process that facilitates interaction among consumers and providers such that individual consumers are enabled to more readily access the content and services of providers, and individual providers are enabled to more effectively and easily deliver their content and services to consumers. This project presents a...
This paper discusses Java Bytecode Obfuscation techniques that make the reverse engineering task more difficult. This paper is structured as follows: Java virtual machine and Java language specifications are discussed first. Then the paper talks about different techniques for protecting software and then details one promising approach named Obfuscation. The...
Shape transformation is a technique for gradually changing one geometric shape to another. A recent approach presents the use of thin-plate radial basis functions as opposed to traditional "blobby sphere" implicit functions. Without the explicit evaluation of he energy function, this approach combined the two traditional steps into one by...
In this thesis, a novel Direct-Charge-Transfer (DCT) integrator structure is proposed, which can settle much faster than regular switch-capacitor integrators. A new Spread-Spectrum Dynamic Element Matching (SS-DEM) algorithm is also introduced, which can effectively spread or shape the nonlinearity error of multi-bit DAC in the feedback path, thus improve the...
This thesis examines substrate noise coupling for NMOS transistors in heavily doped substrates. The study begins with the analysis of an NMOS transistor switching noise in a digital inverter at the device level. A resistive substrate network for the NMOS transistor is proposed and verified. Coupling between N+- P+ contacts...
There has been tremendous technological advancement in the area of high-speed indoor wireless local area networks (WLAN's) in recent years. All the existing tech- nologies such as IEEE 802.11a,b are bandwidth limited and high powered systems. The challenge any wireless technology faces is to minimize both the power consumption and...
The Advanced Encryption Standard (AES) is the new standard for cryptography and has gained wide support as a means to secure digital data. Hence, it is beneficial to develop an implementation of AES that has a high throughput. SIMD technology is very effective in increasing the performance of some cryptographic...
This thesis presents the results of two studies that investigate the question of what interruption-styles are most appropriate for end-user programmers who are debugging programs. In the studies, end-user programmers are presented with surprises that encourage them to investigate, use, and learn about debugging devices in their programming environment. We...
Statistics and Metrics Generator (SMG), is a software tool that gathers, stores and reports
performance and execution metrics for a web-based software installation process. The
purpose of this project was to develop a software utility that provides feedback about software
download and installation process efficiency. A web-based software installation is...