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...
This thesis presents Silencer!, a fully automated, schematic-driven tool for substrate noise coupling simulation and analysis. It has been integrated in the CADENCE DFII environment and seamlessly enables substrate coupling analysis in a standard mixed-signal design flow. Silencer! aids IC designers in the analysis of substrate noise coupling at different...
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...
Coarse resolution imagery, such as that produced by the MODIS instrument, poses the challenge of estimating sub-pixel proportions of di erent land cover types. This problem is di cult because of the variety and variability of vegetation within individual pixels. This thesis describes and compares two existing algorithms for estimating...
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...
In its simplest form, the process of diagnosis is a decision-making process in which the diagnostician performs a sequence of tests culminating in a diagnostic decision. For example, a physician might perform a series of simple measurements (body tem- perature, weight, etc.) and laboratory measurements (white blood count, CT scan,...
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...
The objective of this thesis is to contribute to the development of p-type materials for transparent electronics applications. Thin films of ®-BaCu2S2, a p-type semi-transparent semiconductor, are fabricated and characterized. ®-BaCu2S2 has a transmittance of 60% to 80 % in the visible portion of the electromagnetic spectrum. The mobility, conductivity,...
The objective of this dissertation is to introduce low-cost processing methods for the fabrication of ZnO transparent thin-film transistors (TTFTs). A novel method for depositing ZnO body layers via spin-coating of a zinc nitrate-based spin solution is presented. The processing conditions of spin-coated ZnO are optimized to produce continuous and...
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...
Strategies for simulation and measurement of substrate noise have been analyzed using various digital and analog circuits fabricated in the TSMC 0.35um heavily doped CMOS process. The measurements validate a substrate noise coupling macromodel that has been used to obtain the simulation results. The simulations and measurements also substantiate the...
Phase-locked loop (PLL) frequency synthesizers lie at the heart of most radio transceivers. An important objective of the electronics and communications industry is to design high-speed building blocks which dissipate the lowest possible power, and to ac- complish this with the cheapest technology. The dual-modulus prescaler is one of the...
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...
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...
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...
A comparison and analysis of jitter for five different architectures of ring oscillators using a novel simulation technique developed by Professor Forbes' group is presented. Ring oscillators have become an essential building block in many digital and synchronous communications system due to their integrated nature and are widely used in...
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...
Advanced low power devices promote the development of micro power generators (MPGs) to replace the batteries to power them. Due to the trend in decreasing integrated circuit (IC) supply voltages, power supply designers are facing more and more serious challenges. The objective of this research is to design a power...
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...
Many new applications of energy system devices have been developed to save energy, improve the controllability and stability of industrial processes, and reduce the weight, volume and cost of consumer devices. Due to the novelty of these devices, traditional empirical methods and lumped-parameter circuit theory methods are not sufficient for...
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...
In the first part of this dissertation, low frequency l/f or flicker noise in the frequency range of Hz to kHz has been identified and demonstrated to be described by temperature fluctuations in heat conduction in bipolar transistors operated at higher power densities. This noise phenomenon is not described by...
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,...
The objective of this work is to explore the feasibility of replacing conventional op-amps with inverters in switched-capacitor (SC) circuits. In order to verify the idea, a low-pass filter (LPF) and a second-order delta-sigma (∆Σ) analog-todigital converter (ADC) are designed in the 0.5-m CMOS technology. The low-pass filter structure is...
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...
Embedded passives in multi-layer media have gained importance for offering an attractive solution to the implementation of off-chip passive components in RF and mixed signal circuits, especially for wireless applications. Among the passive devices, power dividers and combiners are extensively used for a host of applications including balanced mixers, phase...
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...