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Articles 121 - 150 of 850
Full-Text Articles in Electrical and Electronics
Real-Time Multi-Spectral Image Processing On The Adsp-Bf533 Dsp, Stephen Niall Coffey
Real-Time Multi-Spectral Image Processing On The Adsp-Bf533 Dsp, Stephen Niall Coffey
Theses
As the need to process multi-spectral images in real-time is becoming more prevalent, the pressure on Integrated Circuit (IC) manufacturers to produce cheap and reliable devices capable of handling the demands of such operations is growing. This project investigates the ADSP-BF533 Blackfin® Digital Signal Processor (DSP) and its ability to support a real-time multi-spectral imaging system. The Blackfin® DSP, incorporating the Analog Devices/Intel Micro Signal Architecture (MSA), are a broad family of 16-bit fixed-point product with a dual Multiply Accumulate (MAC) core.
Using the MicroC/OS-II Real-time Operating System (RTOS), which is a completely portable and scaleable pre-emptive real-time kernel, the …
A 10-Bit 100msample/S Pipeline Analog- To-Digital Converter In Cmos, Pieter Berkelaar
A 10-Bit 100msample/S Pipeline Analog- To-Digital Converter In Cmos, Pieter Berkelaar
Theses
High speed, medium resolution ADC’s, are required for many applications, including wireless receivers, ultrasound systems, wireline interfaces, cameras and camcorders. Low power dissipation is important, particularly for portable equipment where battery life must be maximised. The pipeline ADC architecture is particularly suited to such applications. Its strength comes from the manner in which it performs a conversion, distributing the work in time and amongst successive stages. These stages operate concurrently, maintaining high throughput. Each stage is made up of a fully differential switched capacitor sample-and- hold amplifier and some other circuitry. Designing these circuits to operate at l00MHz is extremely …
An Evaluation Of Model-Based Predictive Control, Daniel Czarkowski
An Evaluation Of Model-Based Predictive Control, Daniel Czarkowski
Theses
This thesis attempts to determine whether advanced control algorithms offer any real benefits to the process industry in terms of optimising single-input single output process units. To establish this, an ideal PID controller, Two Degree of Freedom (2 DOF) PID Controller and the Generalised Predictive Controller (GPC) are compared. A common design philosophy is applied based on optimising performance subject to constraints on robustness. Specifically, three different designs are examined; minimum subject to constraints on the gain and phase margin, minimum lAE subject to constraints on the modulus margin and minimum lAE subject to constraints on the input sensitivity function. …
Robust Colour Segmentation Under Dynamic Lighting Conditions, Noreen Mary Looney
Robust Colour Segmentation Under Dynamic Lighting Conditions, Noreen Mary Looney
Theses
Traditionally, the issue of colour constancy has limited the success of colour image segmentation algorithms. Numerous methods exist to achieve colour constancy for different applications. The principal contribution of this thesis is the investigation of a suitable technique for the problem of robust colour based object detection.
Appropriate colour models are investigated and analysed in order to assess their ability to enhance the isolation process. Models that possess suitable colour constancy characteristics are chosen for use with image segmentation algorithms. Reviews of existing sur\'eys of image segmentation algorithms are appraised for the emergence of a suitable colour image segmentation technique. …
Characterisation, Modelling And Performance Evaluation Of Cmos Integrated Rf-Mems Multielectrode Tunable Capacitor, Zbigniew Olszewski
Characterisation, Modelling And Performance Evaluation Of Cmos Integrated Rf-Mems Multielectrode Tunable Capacitor, Zbigniew Olszewski
Theses
The circuits used in telecommunications are made of two types of components; active integrated circuits that have continuously been improved together with the evolution of the Si technology and off-chip and on-chip passive components. The latter did not profit from much development and now constitute the bottleneck for further integration of RF (Radio Frequency) integrated circuits. MicroElectroMechanical Systems (MEMS) is rapidly emerging as an enabling technology to yield a new generation of high performance components to replace off-chip (not integrated) and on-chip (poor performance) counterparts. The RF components (RF-MEMS) that can be fabricated with MEMS technology are mainly the resonator, …
Automated Control Of Led-Based Illumination Using Image Analysis Metrics, Stephen Mills
Automated Control Of Led-Based Illumination Using Image Analysis Metrics, Stephen Mills
Theses
This project discusses a microprocessor controlled illumination system that covers the visible spectrum. It uses multiple discrete wavelength LEDs. Spatial and spectral illumination profiles are achieved by controlling LED currents with an array of voltage controlled current sources. A highly efficient polycarbonate holographic diffuser is used to improve the uniformity of the distribution. System design is underpinned by accurate characterisation and modelling of the LEDs used.
Image analysis techniques are then used to parameterise the recorded scene and to provide a figure of merit for the quality of the illumination. Several functions such as contrast, low/high saturation, average brightness and …
Multispectral Camera Control And High Speed Image Transfer Using Lossless Hardware Compression, Padraig Ryan
Multispectral Camera Control And High Speed Image Transfer Using Lossless Hardware Compression, Padraig Ryan
Theses
This work provides extensions of a standard D-Cam/Firewire digital camera platform for use within a multispectral imaging setting and includes real-time lossless image compression targeted at the re-configurable environment of an FPGA. The control and image acquisition structures specific to multispectral systems are detailed with respect to an embedded firmware solution, complementary host PC software driver routines, and camera hardware control infrastructures. The augmentation of the standards based implementation is discussed without compromising compliance with underlying specifications. The mandate for image data acquisition includes glue logic to efficiently transmit data via a high-speed communications pipe, IEEE - 1394 in this …
Controller Design And Web-Based Simulation For A Pasteurisation Process, Luis Torres
Controller Design And Web-Based Simulation For A Pasteurisation Process, Luis Torres
Theses
The basic PID controller remains the most commonly used automatic feedback control technique in industry. Many tuning techniques exist for this controller and the use of tuning rules remains very popular, both in industry and academia. This thesis is concerned with the practical evaluation of a selected number of PID tuning rules. The rules were to be evaluated on an industrial pilot-scale milk pasteurisation process. However, most of these rules could not be tested on the real plant as the industrial distributed control system was quite inflexible and did not permit many of the more advanced PID structures e.g. two-degree …
Carrier Transport In Ge Nanowires And One Dimensional Si/Ge Heterojunctions, Eun Kyu Lee
Carrier Transport In Ge Nanowires And One Dimensional Si/Ge Heterojunctions, Eun Kyu Lee
Theses
Ge Nanowires (Ge NWs) on single crystal, (100) and (111) oriented n-type Si substrates were grown via the vapor-liquid-solid (VLS) mechanism and studied with respect to their electrical properties.
Using different contact geometries, direct current (DC) and alternating current (AC) electrical and photoelectrical measurements were carried out at room temperature to investigate electrical properties of Ge NWs and Ge NWs/Si substrate one-dimensional (1 D) heterojunctions (HJs). A rectifying junction behavior is observed at NWs/substrate interface, but many orders of magnitude greater AC conductance than DC in Ge NW volume is measured at high frequencies. The obtained experimental data are consistent …
Detection Of Denial Of Service Attacks Using Database Queries, Dmytro Zakhalyavko
Detection Of Denial Of Service Attacks Using Database Queries, Dmytro Zakhalyavko
Theses
In the current intrusion detection world, most intrusion detection systems output data into flat files. This project was conducted in order to improve intrusion detection data and alerts by writing them into a database system and analyzing them with SQL. A database plug-in was developed that helps to transition the data from an intrusion detection system to a database. Storing, analyzing, categorizing, and accessing data are major advantages and reasons for using databases in intrusion detection. Security analysts have to constantly perform the difficult task of sorting through a haystack of attack alerts, many of which turn out to be …
Spectrum Control And Iterative Coding For High Capacity Multiband Ofdm, Divaydeep Sikri
Spectrum Control And Iterative Coding For High Capacity Multiband Ofdm, Divaydeep Sikri
Theses
The emergence of Multiband Orthogonal Frequency Division Modulation (MB-OFDM) as an ultra-wideband (UWB) technology injected new optimism in the market through realistic commercial implementation, while keeping promise of high data rates intact. However, it has also brought with it host of issues, some of which are addressed in this thesis.
The thesis primarily focuses on the two issues of spectrum control and user capacity for the system currently proposed by the Multiband OFDM Alliance (MBOA). By showing that line spectra are still an issue for new modulation scheme (MB-OFDM), it proposes a mechanism of scrambling the data with an increased …
Investigation Into The Current Statistical Distribution For Oxide Breakdown Versus The Oxide Thickness Used In Integrated Circuit Manufacture, Eoin James O Driscoll
Investigation Into The Current Statistical Distribution For Oxide Breakdown Versus The Oxide Thickness Used In Integrated Circuit Manufacture, Eoin James O Driscoll
Theses
A critical aspect of integrated circuit manufacturing is the reliability of the components, in particular the gate oxide of transistors and capacitors. Accelerated stress tests are used for reliability predictions of gate oxides. There are two statistical distributions, which can be applied to stress test failure data, namely the Lognormal or the Weibull distributions. The failure data can fit each distribution equally well. However the use of either distribution will give vastly different lifetime predictions and their correct use is crucial for accurate lifetime prediction. A statistical based test, developed with Monte Carlo data, which is designed to decide if …
A Statistical Ultra Wideband Indoor Channel Model And The Effects Of Antenna Directivity On Multipath Delay Spread And Path Loss In Ultra Wideband Indoor Channels, Jason Anthony Dabin
A Statistical Ultra Wideband Indoor Channel Model And The Effects Of Antenna Directivity On Multipath Delay Spread And Path Loss In Ultra Wideband Indoor Channels, Jason Anthony Dabin
Theses
Ultra-wideband (UWB) indoor frequency domain channel measurements have been performed in the 2 GHz to 6 GHz frequency band using three different transmitter/receiver (Tx/Rx) antenna combination pairs. The effects of antenna directivity on path loss and multipath propagation in the channel were analyzed extensively for various omni-directional and directional antenna combinations. A statistical model of the path loss in the channel is presented, where the parameters in the model (i.e., path loss exponent and shadow fading statistics) are dependent on the particular Tx/Rx antenna combination. Time domain statistics of the channel (i.e., mean delay spread and RMS delay spread) are …
Si-Sio2 Interface Behavior In N-Mosfets With Screening Potential During High-Field Injection, Purushothaman Srinivasan
Si-Sio2 Interface Behavior In N-Mosfets With Screening Potential During High-Field Injection, Purushothaman Srinivasan
Theses
This work investigates the screening of hot carrier stress degradation in n-channel MOSFETs when the devices were exposed to plasma processing. Devices with various antenna ratios were subjected to current stress (both gate injection and substrate injection) while the source and drain terminals were reverse biased by a screening potential followed by hot carrier stress. It was observed that screening of the drain edge was effective for both gate injection and substrate injection at different screening potentials. The hot carrier lifetime is directly related to interface state density (Dit), measured by charge pumping method. The results suggest that hot electron …
Study Of Design Tradeoffs Of Dram And Sram Memories, Using Hspice Computer Simulation, Bageshri Kale
Study Of Design Tradeoffs Of Dram And Sram Memories, Using Hspice Computer Simulation, Bageshri Kale
Theses
Semiconductor random access memories are complex systems that can be described by performance parameters such as memory cycle time, access delays, storage capacity, bit packing density, chip area and retention time. In this thesis, tradeoffs between cycle time, chip area, and storage size as reflected by bit line capacitance (Cbl) were studied as a function of particular design variables: memory cell capacitance (Cc); CMOS flip-flop sense amplifier (SA) transistor sizes; and size of precharge (PC), and word line (WL) switches. Performance was optimized using circuit simulation software, HSPICE, to observe DRAM and SRAM waveforms. With TSMC 0.18 micron technology, minimum …
Configurable Computer Systems Can Support Dataflow Computing, Anish Arvind Sathe
Configurable Computer Systems Can Support Dataflow Computing, Anish Arvind Sathe
Theses
This work presents a practical implementation of a uni-processor system design. This design, named D2-CPU, satisfies the pure data-driven paradigm, which is a radical alternative to the conventional von Neumann paradigm and exploits the instruction-level parallelism to its full extent. The D2-CPU uses the natural flow of the program, dataflow, by minimizing redundant instructions like fetch, store, and write back. This leads to a design with the better performance, lower power consumption and efficient use of the on-chip resources. This extraordinary performance is the result of a simple, pipelined and superscalar architecture with a very …
Pulsed Laser Ablation Deposition And Optical Characterization Of Hexagonal-Wurtzite Silicon, Berzelius Ybanez Cada
Pulsed Laser Ablation Deposition And Optical Characterization Of Hexagonal-Wurtzite Silicon, Berzelius Ybanez Cada
Theses
Hexagonal-wurtzite silicon phase silicon is an unusual polymorph of silicon with potentially useful electro-optical properties. Previous studies using a simple deposition system demonstrated that laser ablation of the standard cubic-diamond silicon produces droplets containing hexagonal-wurtzite crystallites. In order to study the process parameters and to deposit larger hexagonal crystals, a new pulsed laser ablation system with variable parameters was assembled and tested. Deposition expenments were performed in high vacuum with different laser pulse power. Raman spectroscopy showed that the new system successfully produces hexagonal-wurtzite silicon. The droplet size distributions, measured with an optical microscope, were found to depend on the …
Development Of A Low Jitter Multiplying Delay Locked Loop, Ian Kennedy
Development Of A Low Jitter Multiplying Delay Locked Loop, Ian Kennedy
Theses
The clock generator is a critical component in high-speed wireline communication systems. The clocks in these systems mark time at precise regular intervals. Any deviation of the clock edges from these ideal time points is called jitter and it degrades the overall integrity of the communication system. This thesis looks at both phase locked loops (PLLs) and delay locked loops (DLLs) and their ability to provide these precise clocks. Expressions for the thermal noise-induced jitter in both the PLL and DLL are compared. From this, the DLL is shown to possess the potential for better jitter performance. However, to realise …
Delivery Of Wireless Ad Hoc Services Using Jini, Sinead Cummins
Delivery Of Wireless Ad Hoc Services Using Jini, Sinead Cummins
Theses
Traditionally, networks were planned infrastructures consisting mainly ot desktop machines and servers. As a result of the careful planning carried out prior to their construction, these networks were easily managed and controlled by network administrators. Today these networks are joined by cell phones, PDAs and other handheld devices as well as a host of sensors. This has led to a migration from traditional networks to ad hoc networks.
One way to envisage what this new environment will be like is to imagine what life will be like at the edge of the network. Today the edge mostly consists ot clients …
A Sip Based Multimedia Messaging Service, Donna Griffin
A Sip Based Multimedia Messaging Service, Donna Griffin
Theses
The Session Initiation Protocol (SIP) is the protocol of choice for establishing multimedia sessions in Universal Mobile Telecommunications System (UMTS) networks as stated by 3GPP. SIP is a protocol that will merge together the cellular and Internet worlds and is also scalable, highly available and extensible. It enables mobile carriers to extend operations, administration, maintenance and provisioning (OAMP) in one application to all applications. In addition, while SIP permits presence. Instant Messaging, File Sharing etc., its ultimate value lies in seamlessly aggregating these applications in more powerful offerings, such as Multimedia Messaging, Push to Talk and Voice over IP.
Multimedia …
Performance Estimation Of A Sip Based Push-To-Talk Service For 3g Wireless Networks, Eoin O'Regan
Performance Estimation Of A Sip Based Push-To-Talk Service For 3g Wireless Networks, Eoin O'Regan
Theses
Push To Talk (PTT) services have been in existence for several decades providing dispatch services via two-way radio such as walkie-talkies. For a number of years now PTT services have been available for use over mobile phone networks. These mobile PTT services have occupied a niche market with business users and have been provided on proprietary networks that do not enable roaming.
Over the past year there has been an explosion of interest in the concept of PTT provided over mobile networks using Internet Protocol (IP) technology. This service uses cellular access and radio resources more efficiently than circuit-switched cellular …
Enhancement Of Linear Prediction Coefficient Quantisation In The 3g Adaptive Multi Rate Speech Coder, John Raymond Mccarthy
Enhancement Of Linear Prediction Coefficient Quantisation In The 3g Adaptive Multi Rate Speech Coder, John Raymond Mccarthy
Theses
Most speech coding algorithms in use today utilise the source-filter model of human speech production in which speech is modelled as the response of a time varying, linear, all-pole, synthesis filter to an input excitation. In mobile communications, it is the coefficients of this filter and details of the excitation that are transmitted. The filter coefficients are first quantised using a limited number of bits. Due to coefficient sensitivity, direct quantisation of the filter coefficients may lead to an unstable filter during speech synthesis at the receiver and hence an alternative representation is needed. Line Spectral Frequencies (LSFs) have evolved …
Photonic Crystals Composed Of Thick Inductive And Capacitive Meshes, Jay Shah
Photonic Crystals Composed Of Thick Inductive And Capacitive Meshes, Jay Shah
Theses
The transmission properties of metal meshes are studied for single meshes, photonic double layers and photonic crystals. Simulations are performed with the Flomerics Micro-Stripes program for light of infrared and millimeter wavelengths. The Micro-Stripes program solves Maxwell's equations numerically and, for simulations of the transmittance of metal meshes, has been proven as good as an experiment. Input data are the geometrical parameters, the indices of refraction and the conductivity, chosen according to the Drude model. The light is assumed to be at normal incidence and the simulation results are compared with experiments.
Single layers of inductive meshes are studied for …
Transport Properties Of Nc-Si / A-Sio2 Superlattices And Their Applications In Non-Volatile Memory, Lakshmi Susmitha Koneru
Transport Properties Of Nc-Si / A-Sio2 Superlattices And Their Applications In Non-Volatile Memory, Lakshmi Susmitha Koneru
Theses
The dc current-voltage characteristics, ac conductivity, equivalent capacitance, photocurrent transients of the n-Si/nanocrystalline-Si/amorphous-SiO2/Al heterostructure were measured in a wide range of illumination intensities for temperatures from 4.2 K to 300 K. Electrical transport properties of the nanocrystalline-Si/amorphous-SiO2 superlattices were discussed. The observed domination of the electron component at negative bias and of the hole component at positive bias above 0.7 V in a dc current allows to separate transport features of electrons and holes in a nc-Si/a-SiO2 superlattices. Transport of electrons is thermally activated if potential barrier at c-Si/SL interface of 70 meV is suppressed and …
Elastic Brain Image Registration Using Mutual Information, Srisheela Devabhaktuni
Elastic Brain Image Registration Using Mutual Information, Srisheela Devabhaktuni
Theses
Image Registration is the determination of a geometrical transformation that aligns points in one image of an object with corresponding points in another image. The source image is geometrically transformed to match the target image. The geometric transformation can be rigid or non-rigid. Rigid transformations preserve straight lines and angles between straight lines. The basic rigid transformations are rotation, scaling and translation.
In this thesis non-rigid registration using B-splines is the method being used to take into account the elastic change in the brain structure. The B-spline equation is a type of curved transformation that does not preserve the straightness …
Deposition And Characterization Of Laser-Ablated Silicon, Wenwen Luo
Deposition And Characterization Of Laser-Ablated Silicon, Wenwen Luo
Theses
Laser ablation is a powerful thin film deposition and material processing technology. In the Nonlinear Nanostructure Lab at NJIT, silicon films deposited by laser ablation have been studied for the potential applications in nonlinear optoelectronic devices. The previous studies have suggested that the deposited silicon has a hexagonal symmetry, being a polymorph of silicon that previously has been obtained only at very high pressure. This thesis is part of the continuous study and characterization of this new structure. The objective of the research was to gain better understanding of the hexagonal silicon properties as well as the mechanism that lead …
Service Differentiation In Multihop Wireless Packet Networks, Ilker Onat
Service Differentiation In Multihop Wireless Packet Networks, Ilker Onat
Theses
This work explores the potential of link layer scheduling combined with MAC layer prioritization for providing service differentiation in multihop wireless packet networks. As a result of limited power, multihop characteristic and mobility, packet loss ratio in wireless ad hoc networks tends to be high compared to wireline and one-hop mobile data networks. Therefore, for wireless ad hoc networks, DiffServ-like distributed service differentiation schemes are more viable than hard QoS solutions, which are mainly designed for wireline networks. The choice and implementation of proper queuing and scheduling methods, which determine how packets will use the channel when bandwidth becomes available, …
Study Of Mosfet Degradation Under Substrate Injection And Hot Carrier Degradation, Bhawar S. Patel
Study Of Mosfet Degradation Under Substrate Injection And Hot Carrier Degradation, Bhawar S. Patel
Theses
With continued scaling of MOSFET's, the reliability of thin gate oxides is becoming increasingly important. Degradation issues due to fabrication technology may result in misinterpretation unless the actual physical situation arising at source, drain, gate and substrate of a transistor during processing is understood. This degradation is prominent in plasma processing due to wafer charging which occurs due to the reactive ions in the plasma. The voltages developed at source and drain junctions, depending upon polarity relative to the substrate cause the source and drain junctions to be forward biased or reverse biased. Keeping in view this type of physical …
Co-Operative Location Updates For Mobile Nodes For Cellular Networks, Samir Shah
Co-Operative Location Updates For Mobile Nodes For Cellular Networks, Samir Shah
Theses
In current pure cellular networks, each and every mobile node updates it's location to the particular base station separately following certain algorithms, say timer based, mobility based or both. For the next generation wireless networks, which we can consider as a highly dense network, such location update algorithms prove to be very costly in the terms of overall location update traffic to the base station and average battery usage by each mobile node for location updates due to large number of mobile nodes for particular base station area.
Instead of using such one-to-one link for location updates, this report describes …
A Combined Channel-Modified Adaptive Array Mmse Canceller And Viterbi Equalizer, Richard M. Friedman
A Combined Channel-Modified Adaptive Array Mmse Canceller And Viterbi Equalizer, Richard M. Friedman
Theses
In this thesis, a very simple scheme is proposed which couples a maximum-likelihood sequence estimator (MLSE) with a X-element canceller. The method makes use of the MLSE's channel estimator to modify the locally generated training sequence used to calculate the antenna array weights. This method will increase the array's degree of freedom for interference cancellation by allowing the dispersive, desired signal to pass through the array undisturbed. Temporal equalization of the desired signal is then accomplished using maximum-likelihood sequence estimation. The T-spaced channel estimator coefficients and the array weights are obtained simultaneously using the minimum mean square error criteria. The …