Engineering Commons^™

Entropy And Certainty In Lossless Data Compression, James Jay Jacobs

Dissertations

Data compression is the art of using encoding techniques to represent data symbols using less storage space compared to the original data representation. The encoding process builds a relationship between the entropy of the data and the certainty of the system. The theoretical limits of this relationship are defined by the theory of entropy in information that was proposed by Claude Shannon. Lossless data compression is uniquely tied to entropy theory as the data and the system have a static definition. The static nature of the two requires a mechanism to reduce the entropy without the ability to alter either …

Spatial Frequency Localization In Mammograms Using Wavelets, Tomislav Bujanovic

Dissertations

Microcalcifications are residual calcium deposits that are often the first signs of developing breast abnormalities that may lead to breast cancer. Up to 30% of cancerous lesion in diagnosed breast cancer cases could have been detected earlier through mammogram screenings if the right tools were available. While the detection of calcifications may be easier in fatty backgrounds, it is challenging in dense parenchyma, suggesting the need for more sensitive tools for accurately identifying suspicious regions in mammograms and propping a computer-aided system for further target classification. Therefore, the objective of the research work in this dissertation is to develop a …

Simulation, Synthesis, And Characterization Of Hydrogels And Nanocomposite Gels., Kamleshkumar J. Suthar

Dissertations

Stimuli-responsive gels are three-dimensional, cross-linked polymeric materials that undergo large physical change in response to the environmental stimuli, like temperature, pH, electrical potential, and irradiation. Ferrogels are colloidaldispersion of magnetic nanoparticles in the hydrogel network. The magnetic nanoparticles are attached to the polymeric network by different adhesive forces; as a result, it becomes sensitive to the applied magnetic field.

The main objective of this research is the simulation, synthesis, and characterization of the hydrogel and ferrogel. Simulation of the hydrogel response was performed for various environmental stimuli using a multiphysics finite element analysis software, COMSOL. The pH and electrical response …

Electrical And Optical Properties Of Carbon Nanotube Intra-Connects And Conductive Polymers, Seon Woo Lee

Dissertations

Growth of individual carbon nanotube (CNT) intra-connects (bridges) between two prefabricated electrodes is a great challenge and a pre-requisite to the development of single electron devices. In this thesis, CNT intra-connects were fabricated and studied. Later on, the intra-connects were deposited with electrically conductive polymer (ECP) in the realization of CNT/ECP hybrids.

The process started by realizing two electrodes with sharp end on a silicon wafer using e-beam lithography. The intra-connects were then grown by use of chemical vapor deposition (CVD) technique. The intra-connects were later electroplated by various conductive polymers. The morphology, electrical conductivity of these intra-connects as well …

Practical Localized Waves Generation, Mohamed Ahmed Salem

Dissertations

Since the early works on localized waves (LW), extensive results were published on this important subject, from both the theoretical and the experimental points of view. Nevertheless, those experimental techniques of LW generation suffer from several shortcomings. A major one is that only pulse peaks were accredited. Either the full profile of the generated pulse was not reported, or it was not closely matching the theoretical profile. Additionally, low resolutions of the generated LWs were reported in the acoustic X-Waves. The conductors of the experiment attributed this effect to the limited bandwidth of the excitation elements.

The interest in the …

Electrohydrodynamic Manipulation Of Multiphase Fluids, Sai C. Nudurupati

Dissertations

In microfluidic devices, the fluid can be manipulated either as continuous streams or droplets. The latter is particularly attractive as individual droplets can not only move but also split and fuse, thus offer a greater flexibility in applications such as a laboratory-on- a-chip. In this thesis, a technique is developed that uses an externally applied electric field for manipulating and removing particles trapped on the surface of a drop. The drop is assumed to be immersed in another liquid with which it is immiscible, and the electric field is generated by placing electrodes on the sides of the microdevice. Both …

Inferring Gene Regulatory Networks From Time Series Microarray Data, Peng Li

Dissertations

The innovations and improvements in high-throughput genomic technologies, such as DNA microarray, make it possible for biologists to simultaneously measure dependencies and regulations among genes on a genome-wide scale and provide us genetic information. An important objective of the functional genomics is to understand the controlling mechanism of the expression of these genes and encode the knowledge into gene regulatory network (GRN). To achieve this, computational and statistical algorithms are especially needed.

Inference of GRN is a very challenging task for computational biologists because the degree of freedom of the parameters is redundant. Various computational approaches have been proposed for …

Analytical, Computational And Experimental Studies Of Capillary Flow In Complex Geometries, Yongqing Peng

Dissertations

The dynamic processes of capillary flow in complex geometries have been studied analytically, computationally and experimentally in this research. A general approach for modeling the capillary flow in arbitrary irregular geometries with straight axis of symmetry is proposed. Using this approach, the governing equation to describe the dynamic capillary rising motion in capillaries with nonuniform elliptical cross-section is first derived under the assumptions of parabolic distribution of the axial velocity and constant contact angle. The calculation results for the capillary flow in different tubes with irregular wall show that, in comparison with existing models that have been tested, the present …

Communications And Positioning In Wireless Networks, Yao Zhao

Dissertations

My doctoral research for the past three years is presented in this report. My research mainly focuses on the communications and positioning for wireless networks and is composed of three parts. First, I explored a new Turbo frequency equalization technique for multiple-input multiple-output (MIMO) wireless communications systems to improve the performance of wireless communications. In the second part of my research, I studied the multiple antenna cooperative communications from the perspective of information theories. The third part of my work is dedicated to extensive research on positioning technology for wireless networks using knowledge of the estimation theory in signal processing.

I/Q Imbalance Mitigation For Space-Time Block Coded Communication Systems, Mingzheng Cao

Dissertations

Multiple-input multiple-output (MIMO) space-time block coded (STBC) wireless communication systems provide reliable data transmissions by exploiting the spatial diversity in fading channels. However, due to component imperfections, the in-phase/quadrature (I/Q) imbalance caused by the non-ideal matching between the relative amplitudes and phases of the I and Q branches always exists in the practical implementation of MIMO STBC communication systems. Such distortion results in a complex conjugate term of the intended signal in the time domain, hence a mirror-image term in the frequency domain, in the data structure. Consequently, I/Q imbalance increases the symbol error rate (SER) drastically in MIMO STBC …

Freeway Speed-Flow Relationships Under Rain And Congested Conditions, Jongho Byun

Dissertations

A procedure to account for the impact of rain and congested conditions on the average speed estimates is provided in this study. Although the Highway Capacity Manual (HCM) provides some discussion on the impact of adverse weather on speed-flow relationships, these impacts are not quantified. Using data collected under rain and congested conditions, a procedure for estimating the average speed under these conditions is provided, which is an improvement over the existing HCM (2000) procedures. Using the speed-flow relationships provided in the HCM (2000) for basic freeway segments as a starting point, new numerical relationships suitable for New Jersey roadways …

Analysis Of Marine Container Terminal Gate Congestion, Truck Waiting Cost, And System Optimization, Chang Qian Guan

Dissertations

As world container volume continues to grow and the introduction of 12,000 TEUs plus containerships into major trade routes, the port industry is under pressure to deal with the ever increasing freight volume. Gate congestion at marine container terminal is considered a major issue facing truckers who come to the terminal for container pickup and delivery. Harbor truckers operate in a very competitive environment; they are paid by trip, not by the hours they drive. Gate congestion is not only detrimental to their economic well-being, but also causes environmental pollution.

This thesis applies a multi-server queuing model to analyze marine …

Optimizing Replenishment Order Quantities In Uncoordinated Supply Chains, Atipol Kanchanapiboon

Dissertations

Many modern supply chains can be described as a series of uncoordinated suppliers. That is each supplier establishes their individual inventory and production policies on both the input and output sides. In these supply links there is minimal coordination between suppliers, and typically only prices and delivery guarantees are contracted. As a consequence, the inventory behavior and associated costs do not exhibit standard patterns. This makes it difficult to model and optimize these chains using classical inventory models. The common approach, therefore, for evaluating uncoordinated supply chains is to use Supply Chain Analytics software. These retrieve operational data from Enterprise …

Heterogeneous Flow Structure And Gas-Solid Transport Of Riser, Jun You

Dissertations

This study aims to understand physical mechanisms of gas-solid transport and riser flow, investigate heterogeneous flow structures of gas-solid transport and their formation mechanism of the in riser flows, both in axial and radial directions. It provides sound interpretation for the experimental observation and valuable suggestion to riser reactor design. Chemical reaction is also coupled with flow hydrodynamics to board the industrial applications. This study mainly focuses on mathematical modeling approach based upon physical mechanism, and endeavor to validate model prediction against available experimental data.

First of all, most important physical mechanisms including inter-particle collision force, gas/solid interfacial force and …

On Modeling And Mitigating New Breed Of Dos Attacks, Amey Bhaskar Shevtekar

Dissertations

Denial of Service (DoS) attacks pose serious threats to the Internet, exerting in tremendous impact on our daily lives that are heavily dependent on the good health of the Internet. This dissertation aims to achieve two objectives:1) to model new possibilities of the low rate DoS attacks; 2) to develop effective mitigation mechanisms to counter the threat from low rate DoS attacks.

A new stealthy DDoS attack model referred to as the "quiet" attack is proposed in this dissertation. The attack traffic consists of TCP traffic only. Widely used botnets in today's various attacks and newly introduced network feedback control …

Sensorimotor Experience In Virtual Environments, Katherine Grace August

Dissertations

The goal of rehabilitation is to reduce impairment and provide functional improvements resulting in quality participation in activities of life, Plasticity and motor learning principles provide inspiration for therapeutic interventions including movement repetition in a virtual reality environment, The objective of this research work was to investigate functional specific measurements (kinematic, behavioral) and neural correlates of motor experience of hand gesture activities in virtual environments stimulating sensory experience (VE) using a hand agent model. The fMRI compatible Virtual Environment Sign Language Instruction (VESLI) System was designed and developed to provide a number of rehabilitation and measurement features, to identify optimal …

Clustered Wireless Sensor Networks, Renita Margaret Machado

Dissertations

The study of topology in randomly deployed wireless sensor networks (WSNs) is important in addressing the fundamental issue of stochastic coverage resulting from randomness in the deployment procedure and power management algorithms. This dissertation defines and studies clustered WSNs, WSNs whose topology due to the deployment procedure and the application requirements results in the phenomenon of clustering or clumping of nodes. The first part of this dissertation analyzes a range of topologies of clustered WSNs and their impact on the primary sensing objectives of coverage and connectivity. By exploiting the inherent advantages of clustered topologies of nodes, this dissertation presents …

Electro Hydrodynamic Manipulation Of The Process Of Self-Assembly Of Particles At Fluid-Fluid Interfaces, Muhammad Mansoor Janjua

Dissertations

This dissertation is divided into two parts, first deals with the numerical study of motion of dielectric particles subjected to nonuniform electric fields and second deals with the process of self-assembly of particles at fluid-fluid interfaces and subjected to uniform electric field normal to the interface. In the numerical study, the particles are moved using a direct simulation scheme (DNS) in which the fundamental equations of motion of fluid and solid particles are solved without the use of models. The motion of particles is tracked using a distributed Lagrange multiplier method (DLM) and the electric force acting on the particles …

Optimizing Container Retrieval Operation At A Port Container Terminal, Dejan Besenski

Dissertations

In the presence of major challenges, where ports are striving to improve their operation and stay competitive in the global market, the issue of port efficiency, particularly the intelligent management of straddle carriers is investigated in this study. A new approach is presented that optimizes container handling equipment operation and is beneficial for the terminal operator in terms of improving productivity, providing faster service and reducing operating cost, Also, the solution provides acceptable service for truckers, The operational strategies presented are able to assess the operation from the truckers' and terminal operators' perspective.

The research is structured into four different …

Surface And Bulk Passivation Of Multicrystalline Silicon Solar Cells By Silicon Nitride (H) Layer : Modeling And Experiments, Chuan Li

Dissertations

The objective of this dissertation is to study passivation effects and mechanisms in Si solar cells, specifically, the surface and bulk passivation by hydrogen-rich PECVD silicon nitride (SiN :H) antireflection layer on multicrystalline silicon (me-Si) solar cells.

The passivation of silicon surface can be achieved in two ways: by field-effect passivation and/or by neutralization of interface states. In other words, the deposition should result in a high value of fixed charge, Qf and /or a low value of interface state density, D1. The surface recombination velocity can be described by Shockley-Read-Hall (SRH) statistics.

Current SRH formalisms have failed to explain …

Precipitation Of Micro/Nanoparticles In Enhanced High Energy Dissipation Mixing Systems, Giuseppe Di Benedetto

Dissertations

Crystallization is the most common unit operation used in the pharmaceutical industry to synthesize active ingredients. Rapid development of a drug candidate is dependent on the ability to produce a desired drug substance with consistent properties, These properties include stability and purity, which are directly affected by the crystallization process and which affect, in turn, bioavailability, drug dissolution rate, drug stability, and shelf life.

The objective of this work is to produce micro/nanoparticle crystals within existent glass-lined pharmaceutical stirred-tank reactors by modifying the current reactor configuration to include features that can increase the local rate of energy dissipation in the …

Experiment And Modeling : Ignition Of Aluminum Particles With A Co2 Laser, Salil Mohan

Dissertations

Aluminum is a promising ingredient for high energy density compositions used in propulsion systems, explosives, and pyrotechnics. Aluminum powder fuel additives enable one to achieve higher combustion enthalpies and reaction temperatures. Therefore, to develop aluminum based novel and customized high density energetic materials, understanding of ignition and combustion kinetics of aluminum powders is required. In most practical systems, metal ignition and combustion occur in environments with rapidly changing temperatures and gas compositions. The kinetics of exothermic reactions in related energetic materials is commonly characterized by thermal analysis, where the heating rates are very low, on the order of 1 -50 …

Phosphate And Thermal Stabilization Of Heavy Metals In Dredged Sediments, Peter Kuria Ndiba

Dissertations

Treatment and reuse of dredged harbor sediments in construction as an alternative to disposal reduces costs and conserves resources. This research focused on leachability of metal contaminants subsequent to phosphate addition and thermal treatment at 700 °C. X- ray absorption spectroscopy (XAS) in combination with principal component analysis, target transformation, and linear combination revealed that in the untreated sediments Zn precipitated as the relatively soluble smithsonite (ZnCO₃) (67%) and adsorbed to hydrous iron oxides (15%) and hydrous manganese oxides (18%). Phosphate addition and calcination resulted in sparingly soluble phases, hopeite (Zn₃₍PO₄)₂.4H_{2 …}

Enhanced Fluidization Of Nanoparticle Agglomerates, Daniel Lepek

Dissertations

Gas fluidization of nanoparticle agglomerates has recently received much attention due to the excellent way in which these novel nanornaterials can be dispersed in a gaseous medium. Nanopowders have a very high surface area to volume ratio which allows them have unique chemical and physical properties especially at the surface. Fluidization is a popular technique for the continuous dispersal of solid materials in the fluidlike state.

Recently it has been found that nanoparticles exist in a highly agglomerate state which allow them to become fluidizable. The fluidization behavior of the nanopowders is dependent on the bulk and material properties of …

Characterization Of Natural Organic Matter And Precursors To Trihalomethanes Using Spectral Flourescence Signatures, Krit Punburananon

Dissertations

Disinfection is an essential process to kill pathogens (i.e., disease causing organisms) in source water during the production of drinking water. Chlorine is most widely used disinfectant because it is effective, affordable, and also provides chlorine residual to ensure that the water is safe through the distribution system. Nonetheless, chlorine reacts with Natural Organic Matter (NOM) and forms potentially carcinogenic Disinfection By-products (DBPs). The major chlorination DBPs are dominantly Trihalomethanes (THMs). However, not all organic compounds are equally reactive to THMs formation.

NOM in water samples collected from the Delaware & Raritan Canal and its tributaries (Central New Jersey) was …

A Novel Storage Area Network (San) Extension Solution Over Passive Optical Networks (Pons), Si Yin

Dissertations

After 9/11 and the 2003 power grid failure in North America, storage area network (SAN) extension has emerged as a critical option to ensure business continuity. However, SAN extension encounters challenges in the access network including the scalability, cost, bandwidth bottleneck, and throughput. In this dissertation, a new solution, SAN extension over passive optical networks (S-PONs), has been proposed to address the above problems. PONs are the mainstream wireline technology for upgrading the megabit-level access solutions (such as xDSL and Cable Modem) into gigabit-level broadband access. To tackle the scalability problem and cost challenge, the S-PON architecture has been designed …

Optimizing Fare Structure And Service Frequency For An Intercity Transit System, Feng-Ming Tsai

Dissertations

This study presents an approach to jointly optimize service headway and differentiated fare for an intercity transit system with an objective of total profit maximization and with consideration given to the economic and social sustainability of the system. Service capacity and fleet size constraints are considered. The optimization problem is structured into four scenarios which are comprised of the combinations of whether the Ranges of Travel Distance (RTD) is fixed or variable and if the time period is for a single period or for multiple periods. A successive substitution method (specifically, a modified Gauss Southwell method) is applied to solve …

Kinematic Synthesis Of Planar Four Bar And Geared Five Bar Mechanisms With Structural Constraints, Yahia Mohammad Al-Smadi

Dissertations

In motion generation, the objective is to calculate the mechanism parameters required to achieve or approximate a set of prescribed rigid-body positions. This doctoral dissertation study is aimed to integrate the classical kinematic analysis of a planar four-bar and geared five-bar motion generation with three structural design constraints. These constraints consider driving link static torque, deflection of the crank and buckling of the follower for a given rigid-body load or constant external load.

This kineto-elastostatic analysis is based on the following assumptions to be considered during the analysis; the crank and the follower are elastic members and the coupler is …