Identifying the most relevant items in an e-commerce site is becoming more and more
difficult nowadays because of the heavy overload of information. A Java Recommender
System that uses Collaborative Filtering techniques has been developed to reduce such
information overload and even personalize the information to the individual’s preference.
The...
End-user specification of Lyee programs is one goal envisioned by the Lyee methodology. But with any software development effort comes the possibility of faults. Thus, providing end users a means to enter their own specifications is not enough; they must also be provided with the means to find faults in...
A variable gain, high linearity, low power baseband filter for WLAN applications is implemented in a 1.5 V 3 V 0.15 μm CMOS process. This fourth-order low-pass filter, which is introduced in the transmit channel as a reconstruction filter between the D/A converter and the mixer, has a measured cut-off...
How can rigorous forms of testing be supported in a way that is both compatible with the visual aspect of visual programming languages, and usable by the audiences using those languages - even when the audience has no background in software engineering? Visual programs are likely to contain at least...
Recently, switched capacitor DC/DC converters are extensively used in portable electronic devices because they feature many advantages, such as high efficiency, small package, low quiescent current, minimal external components and low cost. In this thesis, two step-down switched capacitor DC/DC converters are designed. One has the fixed output options 1.5V,...
Random number generation is important in many fields today. It is particularly important in the field of cryptography when generating nonce values, cryptographic keys, and other data required in many cryptographic applications. The proliferation of small, handheld devices that are typically connected to large networks via a wireless connection requires...
Power and timing requirements are becoming more and more stringent as applications move from less mobile devices to more mobile ones. As such, it is important to optimize these applications as much as possible in order to provide the best solution that is low power and low latency. Although there...
This thesis presents algorithms and tools for the automated design of RF LC CMOS voltage controlled oscillators (VCOs) with low phase noise given a set of specifications. The electromagnetic solver, ASITIC, combined with the circuit simulator, SpectreRF, allows optimization of the VCO circuit parameters and inductor layout. This approach gives...
The transition from second-generation (2G) to third-generation (3G) wireless cellular and cordless telephone systems requires multi-standard adaptability in a single RF receiver equipment. An important answer to this request is the use of Delta-Sigma modulators for IF-to-baseband conversion, which will satisfy the dynamic range requirements for digital signal processing, and...
Estimating the carrier frequency from a modulated waveform is one of the most important functions of a coherent signal receiver. Good performance and low bit error rates are obtained by coherent demodulation. Therefore, exact knowledge of the received signal carrier frequency is critical for communication systems. Also due to the...
The evaluation of the stray-load losses in induction motors is an important part of the efficiency estimation process. However, stray-load losses have several components which are difficult to isolate and calculate. Consequently, they are more readily determined by test. IEEE Standard 112-1996 recommends the testing of electrical induction motors at...
Regression testing is an expensive software engineering activity intended to provide confidence that modifications to a software system have not introduced faults. Test case prioritization techniques help to reduce regression testing cost by ordering test cases in a way that better achieves testing objectives. In this thesis, we are interested...
Approximate string matching is commonly used to align genetic sequences (DNA
or RNA) to determine their shared characteristics. In contrast with the standard
dynamic programming methods which use local edit distance models, the Walking
Tree heuristic method was created to handle non-local changes, e.g., translocations,
inversions, and duplications, altogether and...
The world's oceans contain tremendous renewable energy potentials. It is estimated that if 0.2% of the ocean's untapped energy could be harnessed, it could provide power sufficient for the entire world [1]. This thesis provides a comprehensive description of the state-of-the-art of ocean energy extraction technologies and lessons learned from...
Farm machinery continues to increase in its importance to the agricultural sector. Depreciation, the decline in value of a durable asset over time, represents one of the largest costs of agricultural production. The general objectives of this study were to update and expand the number of Remaining Value (RV) functions...
Advancements in power electronics to higher power levels and faster switching times allow new machine and systems designs, but also create higher stresses on electric machinery insulation. High performance, pulse-width modulated (PWM) inverters are now available for medium voltage drive systems, and are being considered by the U.S. Navy as...
The aim of this dissertation is to develop non-traditional approaches to alternating-current thin-film electroluminescent (ACTFEL) device fabrication. ACTFEL technology suffers from a lack of adequately bright and efficient primary-color phosphors and cannot presently compete in the low-cost display market. Therefore the research presented in this dissertation focuses on an exploration...
This thesis presents an automated methodology to calibrate the substrate profile for accurate prediction of substrate parasitics using Green's function based extractors. The technique requires fabrication of only a few test structures and results in an accurate three layered approximation of a heavily doped epitaxial silicon substrate. The obtained substrate...
The focus of this thesis involves development of highly transparent, n-channel, accumulation- mode thin-film transistors employing a zinc tin oxide (ZTO) channel layer. ZTO-based transparent thin-film transistors (TTFTs) show improved device performance compared to ZnO-based TTFTs. An estimated peak effective mobility for these devices as high as ~100 cm² V⁻¹sec⁻¹...
Sequential supervised learning problems involve assigning a class label to each item in a sequence. Examples include part of speech tagging and text to speech mapping. A very general-purpose strategy for solving such problems is to construct a recurrent sliding window (RSW) classifier which maps some window of the input...
XML is a very versatile data format that has been used to represent many different kinds of data, including web pages, books, business and accounting data, programming interfaces, vector graphics, system logs, and games. In a short span of time, it has gained wide acceptance as the document and data...
With the development of high performance power electronic and semiconductor technologies, Adjustable Speed Drive (ASD) systems are increasingly applied in residential, commercial and industrial applications. Due to the advantages at higher power ratings, the three-level Neutral-Point-Clamped (NPC) Voltage Source Inverter (VSI) is being employed in industrial and traction applications, static...
Pipelined analog to digital converters (ADCs) are very important building blocks in many electronic systems such as high quality video systems, high performance digital communication systems and high speed data acquisition systems. The rapid development of these applications is driving the design of pipeline ADCs towards higher speed, higher dynamic...
Sequential supervised learning problems involve assigning a class label to each item in a sequence. Examples include part-of-speech tagging and text-to-speech mapping. A very general-purpose strategy for solving such problems is to construct a recurrent sliding window (RSW) classifier, which maps some window of the input sequence plus some number...
Modern digital still cameras are equipped with just a single CCD for color image acquisition. Since only one spectral band can be recorded in each pixel, a mosaic of red, green and blue color filters is placed in front of the chip. The process of subsequently calculating a full color...
A tuning technique which tunes the continuous time filter very accurately is proposed in this thesis. This technique overcomes the problem of master slave mismatch, thus tuning the filter accurately. The mismatch minimization is done on power up on foreground while the background tuning is always operational. Once the mismatch...
This thesis presents the contributions to substrate noise due to supply coupling and the effect of pin parasitics on the substrate noise generated by digital circuits. Various sources of substrate noise and their effect on analog circuits sharing the same substrate are discussed. A simulation approach to isolate the various...
The electrical behavior of on-chip interconnects has become a dominant factor in silicon-based high speed, RF, and mixed-signal integrated circuits. In particular, the frequency-dependent loss mechanisms in heavily-doped silicon substrates can have a large influence on the transmission characteristics of on-chip interconnects. To optimize the performance of the integrated circuit,...
This thesis proposes a novel fully digital technique for the estimation and correction of the DAC error in multi-bit delta sigma ADCs. The structure of the DAC error is indicated through a simple model for unit-element based DACs. The impact of the DAC error on the performance of ADC is...
A new comprehensive wide-band compact modeling methodology for single-ended spiral inductors and differential spiral inductors is presented. The new modeling methodology creates an equivalent circuit model consisting of frequency-independent circuit elements for use in circuit simulators. A fast automated extraction procedure is developed for determining the circuit element values from...
End-user programmers are writing an unprecedented number of programs, due in large part to the significant effort put forth to bring programming power to end users. Unfortunately, this effort has not been supplemented by a comparable effort to increase the correctness of these often faulty programs. To address this need,...
Hardware cryptography offers a reliable way to provide security for data that is sent over networks. Security processors have taken the stage in the movement for secure computing. Some of the more prominent security processors belong to the S1 family created by Motorola. The primary goal of this thesis is...
Supervised learning is concerned with discovering the relationship between example sets of features and their corresponding classes. The traditional supervised learning formulation assumes that all examples are independent from one another. The order of the examples contains no information. Nonetheless, many problems have a sequential nature. Classifiers for these problems...
A novel method for modeling bends in coplanar waveguides (CPWs) is described. The CPW can be viewed as a pair of parallel coupled quasi-slot lines. Bends in the CPW are modeled as a non-uniform coupled line system in terms of their even- and odd- mode characteristics. This modeling approach is...
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...
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...
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...
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...
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...
A novel switched-R-MOSFET-C input branch is proposed for low-voltage and high-linearity applications. The tunability is achieved by varying the clock duty cycle using an automatic tuning circuit. This tuning method does not involve a change in gate voltage, and is therefore particularly suitable for low-voltage applications. The advantages of the...
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...
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...