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Full-Text Articles in Engineering

Automated Liquid Dispensing Pin For Dna Microarray Applications, Suganya Parthasarathy Aug 2005

Automated Liquid Dispensing Pin For Dna Microarray Applications, Suganya Parthasarathy

Theses

This thesis describes the research and development of a new liquid dispensing/aspiring system that is capable of producing micro sized spots/droplets for molecular biology research and analysis. In particular, the application is focused on DNA microarray fabrication with the goals of smaller spot size, higher yield, more efficient usage of biological materials, and capability to handle high viscosity liquids. The new system is based on active sensing and control and it is part of a fully integrated robotic microarray system for genomic and proteomic applications. The prototype system handles water as well as thick liquids such as 100% glycerol and …


Multicodes For Improved Range Resolution In Radar, Rhiya Vitto Aug 2005

Multicodes For Improved Range Resolution In Radar, Rhiya Vitto

Theses

Third generation (3G) wireless systems are required to support a variety of communication services like voice, image, motion picture transmission, etc, each of which requires different transmission rates. Multi-code modulation has been introduced therefore as a means of supporting multi-rate services and operating in multi-cell environments [8, 9, 10]. This multi-rate multi-function capability may be used in Radar related applications, too. For example, a single transmitted waveform consisting of two orthogonal codes can be used to simultaneously track a target and obtain high range resolution. Tracking requires low bandwidth and high resolution needs a high bandwidth signal. Orthogonal codes like …


Enhancing End-To-End Quality Of Service Provisioning In Wireless Ad Hoc Networks Using Service Vectors, Didem Gozupek Aug 2005

Enhancing End-To-End Quality Of Service Provisioning In Wireless Ad Hoc Networks Using Service Vectors, Didem Gozupek

Theses

A cross-layer architecture that achieves significant power savings, while enhancing the end-to-end QoS provisioning and granularity in wireless ad hoc networks is proposed in this thesis. Recently, a new concept called service vector has been introduced, which enables an end host to choose different service classes along its data path. This scheme enhances the user benefits from the network services and network resource utilization, while maintaining the simplicity and scalability of the current Differentiated Services (DiffServ) network architecture. This thesis explores the application of this concept on wireless ad hoc networks and provides a cross-layer architecture based on the combination …


Deposition Of Tantalum Thin Films By Rf Sputtering With Substrate Bias, Savita Raina Aug 2005

Deposition Of Tantalum Thin Films By Rf Sputtering With Substrate Bias, Savita Raina

Theses

The effects of energetic ion bombardment on the crystallographic structure of RF sputtered tantalum thin films on different substrates, particularly aluminum and silicon, have been studied. The effect of substrate biasing on ion current and film thickness has been investigated. The study included comparison between substrate ion current of DC sputtering and RF sputtering and also was aimed at finding the process parameters, which could influence the crystallographic phase of Ta film. The characterization of Ta films is carried by RBS and x-ray diffraction techniques.

A magnetron sputtering system with a matching network between the source and the RF generator …


Stereo Vision Algorithm Using Propagation Of Correspondences Along An Array Of Cameras, Danyan Ganjali May 2005

Stereo Vision Algorithm Using Propagation Of Correspondences Along An Array Of Cameras, Danyan Ganjali

Theses

One well known problem in stereo vision is the trade-off between precision and accuracy.

In a conventional two camera model, as the baseline separating the two cameras becomes smaller, the images that both cameras produce become more identical. This results in a more accurate set of correspondences, however at the same time causing less precise depth measurement due to the small angle used for triangulation. Similarly, in a larger baseline model, the depth measurement is more precise while the correspondences are not as accurate as of the shorter baseline model. This thesis proposes a method that promises to solve the …


On Performance Analysis Of Optimal Diversity Combining With Imperfect Channel Estimation, Yong Peng May 2005

On Performance Analysis Of Optimal Diversity Combining With Imperfect Channel Estimation, Yong Peng

Theses

The optimal diversity combining technique is investigated for multipath Rayleigh and Ricean fading channel with additive white Gaussian noise where only imperfect channel knowledge is available at the receiver. The non-observable estimation error contributes as an additive source of noise which is not white. Therefore, the optimal combining weight is derived taking into consideration the imperfect channel knowledge.

The bit error rate for BPSK modulation over correlated Rayleigh and Ricean fading channel is derived for minimum mean square channel estimation using pilot symbol assisted modulation. Analytical result and Monte-Carlo simulation are presented for specific channel and estimation models to demonstrate …


Difference-Expansion Based Reversible Data Hiding And Its Steganalysis, Guangsen Tian May 2005

Difference-Expansion Based Reversible Data Hiding And Its Steganalysis, Guangsen Tian

Theses

A novel reversible data embedding method was reported in a recent IEEE journal article. The method was based on difference expansion (DE) technique. It used redundancy in digital images to achieve a high embedding capacity, while keeping visual distortion of the stego-image low. In this thesis, this technique was studied and experimentally evaluated. An effective steganalysis scheme for this DE-based reversible data embedding method was proposed, which used 12-dimensional feature vectors and a Bayes Classifier. The proposed steganalysis scheme steadily achieved a correct classification rate of 99%.


Performance Of Multi-User Codes In Wireless Communications, Muhammad Tauseef Ulislam May 2005

Performance Of Multi-User Codes In Wireless Communications, Muhammad Tauseef Ulislam

Theses

Multi-user codes are a widely used in transmitting user data from base station to mobile station and vice versa. In wireless communications a signal received by a mobile station goes through different fading channels resulting. These multi-paths add constructively and destructively with different delays and attenuation at the mobile station. The autocorrelation and cross correlation properties of the Multi-user codes play a significant role in extracting the user data from the signal corrupted by multipath fading channel.

The thesis presents a comparison of different Multi-user codes based on their autocorrelation and cross correlation properties. These codes are passed through a …


Analysis Of Mhpdm Algorithm For Data Hiding In Jpeg Images, Pooja Gore May 2005

Analysis Of Mhpdm Algorithm For Data Hiding In Jpeg Images, Pooja Gore

Theses

In the recent years, there has been a great deal of interest in developing a secure algorithm for hiding information in images, or steganography. There has also been a lot of research in steganalysis of images, which deals with the detection of hidden information in supposedly natural images. The first section of this thesis reviews the steganography algorithms and steganalysis techniques developed in the last few years. It discusses the breadth of steganographic algorithms and steganalytic techniques, starting with the earliest, based on LSB flipping of the DCT coefficients, to more recent and sophisticated algorithms for data hiding and equally …


Cyclic Prefix Assisted Block Transmission For Low Complexity Communication System Design, Haibin Huang Jan 2005

Cyclic Prefix Assisted Block Transmission For Low Complexity Communication System Design, Haibin Huang

Theses

This thesis presents new results on cyclic prefix (CP) assisted block transmission for low complexity communication system design. Two important aspects are studied: the CP based low-complexity schemes for channel equalization and channel estimation.

Specifically, based on the simple frequency domain equalization, a low complexity joint receiver is proposed for CP-CDMA system, which is a special application of block transmission.

And in this work the finite impulse response (FIR) model is used for the unknown communication channels. To identify an unknown FIR channel, a novel channel estimation method is proposed by exploiting the cyclic prefix technique. Compared to a conventional …


Optical Properties Of Sige Nanostructures, Varun Sharma Jan 2005

Optical Properties Of Sige Nanostructures, Varun Sharma

Theses

In this thesis, Raman Scattering (RS) and photoluminescence (PL) measurements of Ge nanowires (NWs) grown via vapor-liquid-solid (VLS) using chemical vapor deposition silicon substrates consisting of (100) and (111) crystallographic orientations are reported. Ge NWs grown are ~40 nm in diameter, approximately a micrometer in length, and a sharp narrow Raman peak at ~300cm-1 indicates single crystal quality. An absence of SiGe peak in the Raman spectra indicates that SiGe interdiffusion is insignificant for the NW volume. Low temperature PL-intensity-dependence spectra indicate that the observed emission originates at the Ge NW - Si substrate interface, where SiGe intermixing has …


Study Of Steganalysis Methods, Wen Chen Jan 2005

Study Of Steganalysis Methods, Wen Chen

Theses

Steganography is the art and science of hiding the presence of conmunication by embedding secret message into digital images. The steganographic techniques can be applied in many areas. On one hand, people can benefit from their application. For example, they can be used for copyright protection. On the other hand, these techniques may be used by criminals or terrorists for malicious purposes. For example, terrorists may use the techniques to transmit the secret plan of terror attacks. Law enforcement and security authorities have concerns about such activities. It is necessary to devise the methods to detect steganographic systems. The detection …


A Digital Signature And Watermarking Based Authentication System For Jpeg2000 Images, Rui Jing Jan 2005

A Digital Signature And Watermarking Based Authentication System For Jpeg2000 Images, Rui Jing

Theses

In this thesis, digital signature based authentication system was introduced, which is able to protect JPEG2000 images in different flavors, including fragile authentication and semi-fragile authentication. The fragile authentication is to protect the image at code-stream level, and the semi-fragile is to protect the image at the content level.

The semi-fragile can be further classified into lossy and lossless authentication. With lossless authentication, the original image can be recovered after verification. The lossless authentication and the new image compression standard, JPEG2000 is mainly discussed in this thesis.


Study Of Joint Embedding And Compression On Jpeg Compression Scheme Using Multiple Codebook Data Hiding, Amol Nishikant Sukerkar Jan 2005

Study Of Joint Embedding And Compression On Jpeg Compression Scheme Using Multiple Codebook Data Hiding, Amol Nishikant Sukerkar

Theses

This thesis studies a direct application of multiple codebook data hiding technique in the multimedia applications. It studies the practical implementation of a joint embedding and compression scheme. It presents a study of Type III data embedding technique using multiple codebook design on JPEG-85 compression scheme. The application of the above technique is compared with the Type III data embedding techniques using single codebook design. The comparison is carried out in tenns of the parameters such as mean square error and normalized correlation between the embedded and extracted watermark.

The performance of data hiding rate against the embedding distortion is …


Multispectral Camera Control And High Speed Image Transfer Using Lossless Hardware Compression, Padraig Ryan Jan 2005

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 …


Automated Control Of Led-Based Illumination Using Image Analysis Metrics, Stephen Mills Jan 2005

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 …


An Evaluation Of Model-Based Predictive Control, Daniel Czarkowski Jan 2005

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. …


Real-Time Multi-Spectral Image Processing On The Adsp-Bf533 Dsp, Stephen Niall Coffey Jan 2005

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 …


Characterisation, Modelling And Performance Evaluation Of Cmos Integrated Rf-Mems Multielectrode Tunable Capacitor, Zbigniew Olszewski Jan 2005

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, …


Controller Design And Web-Based Simulation For A Pasteurisation Process, Luis Torres Jan 2005

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 …


A 10-Bit 100msample/S Pipeline Analog- To-Digital Converter In Cmos, Pieter Berkelaar Jan 2005

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 …


Robust Colour Segmentation Under Dynamic Lighting Conditions, Noreen Mary Looney Jan 2005

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. …