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Mining Frequent Generalized Patterns For Web Personalization In The Presence Of Taxonomies, Panagiotis Giannikopoulos, Iraklis Varlamis, Magdalini Eirinaki 2010 University of Peloponnese

Mining Frequent Generalized Patterns For Web Personalization In The Presence Of Taxonomies, Panagiotis Giannikopoulos, Iraklis Varlamis, Magdalini Eirinaki

Magdalini Eirinaki

The Web is a continuously evolving environment, since its content is updated on a regular basis. As a result, the traditional usage-based approach to generate recommendations that takes as input the navigation paths recorded on the Web page level, is not as effective. Moreover, most of the content available online is either explicitly or implicitly characterized by a set of categories organized in a taxonomy, allowing the page-level navigation patterns to be generalized to a higher, aggregate level. In this direction, the authors present the Frequent Generalized Pattern (FGP) algorithm. FGP takes as input the transaction data and a hierarchy …


Challenges Students Face When Solving Open - Ended Problems, Nikos J. Mourtos 2010 San Jose State University

Challenges Students Face When Solving Open - Ended Problems, Nikos J. Mourtos

Nikos J. Mourtos

No abstract provided.


Challenges Students Face When Solving Open - Ended Problems, Nikos J. Mourtos 2010 San Jose State University

Challenges Students Face When Solving Open - Ended Problems, Nikos J. Mourtos

Faculty Publications

Several core aerospace engineering courses at SJSU have been re-designed in an effort to help students develop problem-solving skills. This re-design includes (a) explicit definition of skills and attributes students need to develop to become capable problem-solvers, (b) inclusion of open-ended problems in each of several key, junior-level, core courses, (c) coaching students in the use of Wood’s Problem-Solving Methodology, and (d) development of rubrics to evaluate student performance at each step of this methodology. The paper discusses the application of this process and, in particular, it presents an assessment of student performance in two courses: fluid mechanics and aerodynamics. …


Molecular Simulation Of The Infrared Absorption Cross Section And Thermophysical Properties Of A Polyatomic Fluid, Zhi Liang 2010 Missouri University of Science and Technology

Molecular Simulation Of The Infrared Absorption Cross Section And Thermophysical Properties Of A Polyatomic Fluid, Zhi Liang

Doctoral Dissertations

"The work presented in this dissertation aims at ab initio calculations of the infrared absorption cross section, heat capacity, self-diffusion coefficient, shear viscosity and thermal conductivity of a polyatomic fluid with the aid of statistical mechanics. The simulation is firstly focused on calculating single-molecule properties such as molecular structure, vibrational energy eigen values and transition dipole moments using an efficient method based on the density functional theory. Based on these ab initio results, the infrared absorption cross sections are determined by the Fermi's Golden rule, and the thermophysical properties are determined from molecular dynamics simulations. Using carbon dioxide as an …


Factors Controlling Ductility In Ultrafine Grain Aluminum Alloys Under Monotonic And Cyclic Loading, Partha Sarathi De 2010 Missouri University of Science and Technology

Factors Controlling Ductility In Ultrafine Grain Aluminum Alloys Under Monotonic And Cyclic Loading, Partha Sarathi De

Doctoral Dissertations

"Ultrafine grained (UFG) Al processed by severe plastic deformation (SPD) methods are characterized by high strength and a limited uniform ductility. Friction stir processing (FSP), an offshoot of friction stir welding has emerged as a new technique to produce UFG alloys. FSP-UFG Al alloys show a distinctly different behavior with higher uniform elongation and improved high cycle fatigue life as compared to other SPD processed variants. The objective of this work was to study the microstructural basis for such mechanical behavior in FSP-UFG Al alloys.

To study the mechanical behavior of FSP Al alloys, a subsize bending fatigue and uniaxial …


Experimental And Computational Investigations Of Hydrogen Safety, Dispersion And Combustion For Transportation Applications, Shravan K. Vudumu 2010 Missouri University of Science and Technology

Experimental And Computational Investigations Of Hydrogen Safety, Dispersion And Combustion For Transportation Applications, Shravan K. Vudumu

Doctoral Dissertations

"Hydrogen is an energy carrier that can be produced from a variety of sources, offering one of the viable solutions to the increasing demands for clean and sustainable energy. Compared to the conventional fuels, hydrogen has distinct properties that need to be properly accounted for during its safer storage and delivery as well as more efficient and cleaner utilization. The broader objective of this study is to contribute to the scientific knowledge necessary to overcome key technical barriers to the widespread implementation of hydrogen in transportation applications. Specifically, lower flammability limit of hydrogen is first measured with an enhanced experimental …


Effects Of Optimized And Sub-Optimum Two Degree Of Freedom Lining Tolerances On Modeled Inlet Acoustic Attenuation And Normal Incidence Impedance Measurement At Elevated Temperatures, David R. Burd 2010 Missouri University of Science and Technology

Effects Of Optimized And Sub-Optimum Two Degree Of Freedom Lining Tolerances On Modeled Inlet Acoustic Attenuation And Normal Incidence Impedance Measurement At Elevated Temperatures, David R. Burd

Doctoral Dissertations

"This work first investigates the effect of manufacturing tolerances on realized attenuation for two degree-of-freedom linings with the use of lining models and finite element duct propagation codes. Acoustic linings were created for two turbofan engines that optimize attenuation at takeoff/sideline and approach conditions. Lining physical and geometric parameters were set, which best meet the optimum impedance requirements at two target frequencies. Similar linings were created to investigate sub-optimum designs. Variations of these parameters representing realistic manufacturing tolerances were used to systematically examine the effect on installed impedance and predicted attenuation. Attenuation at sideline and approach conditions was found to …


Development Of Embedded Modulated Scatterer Technique: Single- And Dual-Loaded Scatterers, Kristen M. Donnell 2010 Missouri University of Science and Technology

Development Of Embedded Modulated Scatterer Technique: Single- And Dual-Loaded Scatterers, Kristen M. Donnell

Doctoral Dissertations

"Health monitoring of infrastructure is an important ongoing issue. Therefore, it is important that a cost-effective and practical method for evaluating complex composite structures be developed. A promising microwave-based embedded sensor technology is developed based on the Modulated Scatterer Technique (MST). MST is based on illuminating a probe, commonly a dipole antenna loaded with a PIN diode (also referred to as a single-loaded scatterer, or SLS), with an electromagnetic wave. This impinging wave induces a current along the scatterer length, which causes a scattered field to be reradiated. Modulating the PIN diode also modulates the signal scattered by the probe, …


Adaptive Resource Allocation For Cognitive Wireless Ad Hoc Networks, Behdis Eslamnour 2010 Missouri University of Science and Technology

Adaptive Resource Allocation For Cognitive Wireless Ad Hoc Networks, Behdis Eslamnour

Doctoral Dissertations

"Widespread use of resource constrained wireless ad hoc networks requires careful management of the network resources in order to maximize the utilization. In cognitive wireless networks, resources such as spectrum, energy, communication links/paths, time, space, modulation scheme, have to be managed to maintain quality of service (QoS). Therefore in the first paper, a distributed dynamic channel allocation scheme is proposed for multi-channel wireless ad hoc networks with single-radio nodes. The proposed learning scheme adapts the probabilities of selecting each channel as a function of the error in the performance index at each step.

Due to frequent changes in topology and …


The Functionalization Of Single Wall Carbon Nanotubes For Bioapplications, Pu Zhang 2010 Missouri University of Science and Technology

The Functionalization Of Single Wall Carbon Nanotubes For Bioapplications, Pu Zhang

Doctoral Dissertations

"In the past few years, the functionalization of carbon nanotubes has received considerable attention due to their extraordinary mechanical, electrical, optical and thermal properties. Using single wall carbon nanotube as a platform in bioanalytical and biomedical applications has also been extensively studied. This dissertation consists of four papers. In the first paper, various methods to functionalize single wall carbon nanotubes with immobilized enzyme for bioanalytical application were investigated. It was found that the covalent functionalization method was not an ideal methodology for enzyme addition neither in terms of enzyme loading amount nor activity retention compared to other methods. Use of …


Speech Intelligibility From Image Processing, Andrew Hines, Naomi Harte 2010 Technological University Dublin

Speech Intelligibility From Image Processing, Andrew Hines, Naomi Harte

Articles

Hearing loss research has traditionally been based on perceptual criteria, speech intelligibility and threshold levels. The development of computational models of the auditory-periphery has allowed experimentation via simulation to provide quantitative, repeatable results at a more granular level than would be practical with clinical research on human subjects.


Fpga Implementation Of Pso Algorithm And Neural Networks, Parviz Palangpour 2010 Missouri University of Science and Technology

Fpga Implementation Of Pso Algorithm And Neural Networks, Parviz Palangpour

Masters Theses

"This thesis describes the Field Programmable Gate Array (FPGA) implementations of two powerful techniques of Computational Intelligence (CI), the Particle Swarm Optimization algorithm (PSO) and the Neural Network (NN). Particle Swarm Optimization (PSO) is a popular population-based optimization algorithm. While PSO has been shown to perform well in a large variety of problems, PSO is typically implemented in software. Population-based optimization algorithms such as PSO are well suited for execution in parallel stages. This allows PSO to be implemented directly in hardware and achieve much faster execution times than possible in software. In this thesis, a pipelined architecture for hardware …


Controlling Strength And Permeability Of Silica Investment Casting Molds, Darryl M. Kline 2010 Missouri University of Science and Technology

Controlling Strength And Permeability Of Silica Investment Casting Molds, Darryl M. Kline

Masters Theses

"Investment casting is a metal casting process in which a ceramic mold is created around a disposable pattern using dip coating. The fine silica flour making up most of the mold gives the benefits of a smooth internal mold surface and high density. The high density allows for investment casting molds to be thinner and lighter than sand-based molds, but gives substantially smaller gaps between particles for air flow. This research focused on the design and improvement of the formulation for making investment casting molds with customizable physical properties. Properties of the molds, specifically flexural strength, permeability, and physical structure, …


Development Of An Efficient Super-Resolution Image Reconstruction Algorithm For Implementation On A Hardware Platform, Pestak Thomas C. 2010 Wright State University

Development Of An Efficient Super-Resolution Image Reconstruction Algorithm For Implementation On A Hardware Platform, Pestak Thomas C.

Browse all Theses and Dissertations

There is a growing demand from numerous commercial and military applications for images with ever-improving spatial resolution. However, there are resolution-limiting factors inherent in all imaging systems. Decreasing pixel sizes and/or increasing sensor arrays are not always viable. Super-Resolution (SR) Image Reconstruction is an image processing technique that restores a high-resolution (HR) image from a series of low-resolution (LR) images of a particular scene. Recently, there has been extensive research on robust SR algorithms used for post-processing. The goal of this thesis is to explore the current SR research and design computationally efficient SR algorithms for real-time processing based on …


Experimental Studies Of Turbulent Boundary Layers Over A Rough Forward-Facing Step And Its Coarse Scale Resolution Approximations, Huiying Ren 2010 Wright State University

Experimental Studies Of Turbulent Boundary Layers Over A Rough Forward-Facing Step And Its Coarse Scale Resolution Approximations, Huiying Ren

Browse all Theses and Dissertations

High spatial resolution PIV experiments are performed in the x-y plane at two different spanwise positions to compare the turbulent boundary layers over smooth and rough forward-facing-steps as well as the rough step's two coarse scale-resolution approximations. The Reynolds number based on the step's mean height, Reh, is 3450 and the ratio of the boundary layer thickness to the step's height is δ/h = 8. The roughness topography on the top surface of the rough step is replicated from a realistic turbine blade and is intrinsically three-dimensional and highly irregular. The surface topographies of the coarse scale-resolution …


Hard-Switching And Soft-Switching Two-Switch Flyback Pwm Dc-Dc Converters And Winding Loss Due To Harmonics In High-Frequency Transformers, Dakshina S. Murthy Bellur 2010 Wright State University

Hard-Switching And Soft-Switching Two-Switch Flyback Pwm Dc-Dc Converters And Winding Loss Due To Harmonics In High-Frequency Transformers, Dakshina S. Murthy Bellur

Browse all Theses and Dissertations

The flyback pulse-width modulated (PWM) DC-DC power converter is a very important circuit in switching mode power supply (SMPS) converters for low power applications. The main drawback of the conventional single-switch flyback converter is the high turn-off voltage stress suffered by the switch. The high voltage transients are caused by the resonant behavior of the transformer leakage inductance and the transistor output capacitance, resulting in ringing superimposed on the steady-state switch voltage level. This requires a transistor with higher voltage rating. However, a transistor with higher voltage rating has higher on-resistance causing higher conduction loss. The high voltage ringing also …


Visualization Of Complex Unsteady 3d Flow: Flowing Seed Points And Dynamically Evolving Seed Curves With Applications To Vortex Visualization In Cfd Simulations Of Ultra Low Reynolds Number Insect Flight, Christopher M. Koehler 2010 Wright State University

Visualization Of Complex Unsteady 3d Flow: Flowing Seed Points And Dynamically Evolving Seed Curves With Applications To Vortex Visualization In Cfd Simulations Of Ultra Low Reynolds Number Insect Flight, Christopher M. Koehler

Browse all Theses and Dissertations

Three dimensional integration-based geometric visualization is a very powerful tool for analyzing flow phenomena in time dependent vector fields. Streamlines in particular have many perceptual benefits due to their ability to provide a snapshot of the vectors near key features of complex 3D flows at any instant in time. However, streamlines do not lend themselves well to animation. Subtle changes in the vector field at each time step lead to increasingly large changes between streamlines with the same seed point the longer they are integrated. Path lines, which show particle trajectories over time suffer from similar problems when attempting to …


Population Fit Threshold: Fully Automated Signal Map Generation For Baseline Correction In Nmr-Based Metabolomics, Daniel C. Homer 2010 Wright State University

Population Fit Threshold: Fully Automated Signal Map Generation For Baseline Correction In Nmr-Based Metabolomics, Daniel C. Homer

Browse all Theses and Dissertations

Baseline correction of NMR-based metabolomic spectra is a key step in data processing to elucidate biomarkers of diseased and toxic states. Automated baseline correction methods often use human-selected parameters. Presented is a method for automated baseline correction using parameters selected from and without manipulation of the spectrum. The focus is on generating an accurate signal map based on the differentiating characteristics of baseline noise and signal. The presented method of signal map generation and baseline correction was developed and tested on 13C and 1H NMR spectra. The spectra were as simple as chemical standards containing less than 25 signal peaks …


Ab Initio Simulations Of Hydrogen And Lithium Adsorption On Silicene, Tim H. Osborn 2010 Wright State University

Ab Initio Simulations Of Hydrogen And Lithium Adsorption On Silicene, Tim H. Osborn

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The energies and temperature-dependent dynamics of hydrogen and lithium chemisorption on a silicon nanosheet, called silicene, were studied using density functional theory and molecular-dynamics (MD) simulations. Silicene has a buckled honeycomb structure, and has been fabricated as suspended monolayer sheets and nanoribbons in recent experiments. We calculated the adsorption energies of hydrogen and lithium on silicene for different adsorption ratios between 3.1% and 100%. The studies will clarify the characteristics of these novel and promising nanomaterials, and pave the way for their applications.

For Hydrogen, the adsorption energy had a maximum of 3.01 eV/H for complete hydrogenation, and decreased by …


Charaterization Of Chlorpyrifos Toxicity On The Pancreatic Beta Cell Line Rinm5f, Zhongyu Yan 2010 Wright State University

Charaterization Of Chlorpyrifos Toxicity On The Pancreatic Beta Cell Line Rinm5f, Zhongyu Yan

Browse all Theses and Dissertations

Chlorpyrifos (CPF) is a well-known organophosphate (OP) insecticide that inhibits acetylcholinesterase (AChE). Organophosphates have been shown to induce hyperglycemia in both humans and animals that cannot be explained by AChE inhibition alone. Pancreatic β-cells are responsible for secreting insulin and playing a fundamental role in glucose homeostasis. The aim of this research was to investigate CPF toxicity on the insulin secreting β-cell line RINm5f (RIN). In the first part of this dissertation, we determined that cytotoxic concentrations of CPF between 50 µM and 200 µM induced a dose-dependent increase in RIN cell apoptotic and necrotic death (p<0.05). Lower doses, i.e., 5-25 µM did not induce apoptosis or necrosis. In further mechanistic studies, inhibitors of c-Jun N-terminal kinase (JNK) and P38 pathways, i.e., SP600125 and SB202190, successfully attenuated CPF-induced apoptosis (p<0.05), suggesting cell death is mediated by JNK and/or p38. In addition, N-Acetyl-L-cysteine (NAC), an antioxidant, inhibited apoptosis suggesting that oxidative stress is also involved in RIN cell death. In the second part of this dissertation, low dose CPF's effects on insulin synthesis and secretion was studied. Our results showed that RIN cells treated with CPF for 4 hr exhibited a dose-dependent decrease in insulin secretion in response to stimulation by 50 mM potassium (p<0.05). Insulin secretion stimulated by 25 mM glucose also showed significant decreases upon incubation with various doses of CPF (p<0.05). Insulin synthesis involves proteolytic cleavage of proinsulin at two specific sites. The enzymes responsible for promoting proinsulin cleavage, i.e, prohormone convertase (PC) 1/3 and 2 (PC2), contain a serine hydrolase catalytic triad, His-Asp-Ser, similar to AChE. CPF modification of PC enzymes similar to AChE, could potentially interrupt the conversion of proinsulin to insulin and disrupt insulin secretion. PC2 enzyme activity was significantly inhibited by CPF at concentrations as low as 10 µM (p<0.01). RIN cells, for the first time, were found to secrete proinsulin was through a constitutive instead of a regulated pathway. In summary, our results show that CPF not only exerts a direct cytotoxic effect at concentrations above 50 µM, but also significantly impairs insulin secretion at lower doses. Low dose CPF could potentially affect endocrine function in vivo by inhibiting the proinsulin processing enzyme PC2.


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