Physical Sciences and Mathematics Commons^™

Monochromatization Effect Kinetic Model For Penning Gas Mixtures Emission Mechanisms, Catalina Ciobotaru, Geavit Musa

Turkish Journal of Physics

The monochromatization effect (M-effect), which consists in the reduction of an electronegative-electropositive gas mixtures discharge emission spectrum to only a few or a single line, was largely explained in our previous published papers together with their generation mechanisms, namely the polar ion-ion recombination and the energy resonance condition. This paper presents a kinetic model for the M-effect based on the radiative and collisional processes which appear between 1s_2, 1s_3, 1s_4 and 1s_5 Paschen levels, in Penning gas mixtures, where this effect was observed to be the most powerful.

The Differential Transform Method For Solving Heat-Like And Wave-Like Equations With Variable Coefficients, Khatereh Tabatabaei, Ercan Çeli̇k, Raziyeh Tabatabaei

Turkish Journal of Physics

In this article, Differential transform method is presented for solving heat-like and wave-like equations with variable coefficients. We applied these methods to six examples. This powerful method gives an exact solution. These examples are prepared to show the efficiency and simplicity of the method.

Coupled-Channels Analysis Of K^+ Scattering From ^6li, Ahmed Aly Ebrahim

Turkish Journal of Physics

Differential cross sections for the elastic and inelastic scattering of K^+ at 715 MeV/c from ^6Li are analysed by applying the Watanabe superposition model to the real potential with a phenomenological imaginary potential. The optical potential of ^6Li is calculated in terms of alpha-particle and deuteron or triton and helion optical potentials. The calculated cross sections are consistent with the triton-helion model.

Resonant Electron Transfer And L-Shell Excitation For _{26}Fe^{19+} And _{30}Zn^{23+} Ions, Hassan Ramadan

Turkish Journal of Physics

Resonant transfer and excitation (RTE) involving simultaneous electron capture and projectile L-shell excitation has been calculated for Fe^{19+} and Zn^{23+} ions, in charge states ranging from nitrogen-like to oxygen-like incident on molecular hydrogen over an energy range 0--250 MeV. By the same way the calculations have been performed with helium over an energy range 0--300 MeV. The calculations are carried out using the angular momentum average (AMA) scheme in the isolated resonance approximation (IRA). This method was previously used to calculate RTE cross sections for N-like P^{8+} and Ca^{13+}, where the results are found to agree with the present calculations. …

The Impact Of Hyperfine Interaction On The Charge Radius Of Protons, Majid Amirfakhrian

Turkish Journal of Physics

In this paper, the wave function of a Proton has been calculated via solving the Dirac equation for a three-particle system. Then, the charge radius of the proton was measured. Isospin-Isospin interaction was added to the system as a perturbation factor, and the variation of the charge radius of Proton was considered. Finally, the spin-spin and spin-isospin interactions on the charge radius of the Proton were calculated based on this method.

Bianchi-V Cosmological Models With Viscous Fluid And Constant Deceleration Parameter In General Relativity, Sharad Kandalkar, Pramod Khade, Mohini Gaikwad

Turkish Journal of Physics

In this paper we discuss the variation law for Hubble's parameter, average scale factor in spatially homogenous anisotropic Bianchi Type V space-time that yields a constant value deceleration parameter. Using the law of variation for Hubble's parameter, exact solutions of Einstein's field equations are obtained for Bianchi-V space time filled with viscous fluid in two different cases where the universe exhibits power law and exponential expansion. We investigate a number of solutions with constant and time varying cosmological constant together with variable and constant bulk viscosity. We find that the constant value of deceleration parameter is reasonable for the present …

A Fresh Look At Thermal Field Emission From Tungsten Tip, Ahmed Abdurrahman Ahmed Al-Tabbakh

Turkish Journal of Physics

Electron emission from clean tungsten tips has been investigated at different temperatures and applied electric field. Emission mechanism is analyzed on the basis of the Fowler-Nordheim (FN) model and a parameter extraction model based on elimination of field enhancement factor. The suggested extraction model of the physical and geometrical parameters is found fairly adequate to resolving the apparently confusing behavior of these parameters and shedding light on the emission mechanism. The observed linear FN plots at low temperatures confirm the predominating effect of the applied field on the electron emission. At elevated temperatures, emission is found to fall in the …

A New Karren Feature: Hummocky Karren, Lukas Plan, Christa Renetzeder, Rudolf Pavuza, Wilfried Körner

International Journal of Speleology

Karren are small-scale landforms on karst surfaces and many types have been described so far. Here we present an apparently new feature which was found on the Hochschwab karst massive in the Northern Calcareous Alps of Austria. So far only few outcrops each having less than 1 m² within a very restricted area have been found. Morphometric analysis reveals that the karren consist of a randomly distributed, dispersed assemblage of small hummocks and depressions in between. The mean distance between neighbouring hummocks is 4 to 5 cm and the mean height is 0.85 cm. Longitudinal sections are gently sinuous. The …

Cycles Of Electronic Health Records Adaptation By Physicians: How Do The Positive And Negative Experience With The Ehr System Affect Physicians' Ehr Adaptation Process?, Cherie Noteboom, Dhundy Bastola, Sajda Qureshi

Research & Publications

The integration of EHR in IT infrastructures supporting organizations enable improved access and recording of patient data, enhanced ability to make improved decisions, improved quality and reduced errors in patient care. Despite these benefits, there are mixed results as to the use of EHR. The literature suggests that the reasons for the limited use relate to policy, financial and usability considerations, but it does not provide an understanding of reasons for physicians’ limited interaction and adaptation of EHR.

Following an analysis of qualitative data, collected in a case study at a hospital using interviews, this research explains how physicians interact …

Multi-Party Multi-Period Supply Chain Coordination, Thin Yin Leong, Michelle Lee Fong Cheong

Research Collection School Of Computing and Information Systems

We apply combinatorial auction as a coordination mechanism to smooth demands placed on suppliers' limited production capacities, allowing several manufacturers to share common suppliers effectively. Products are bidders bidding for parts from suppliers, consuming their capacities in different time periods. The fourth party logistic (4PL) provider acts as the auctioneer to coordinate bids and perform price iterations. We leverage on the strong links between the Lagrangian relaxation method and combinatorial auction, where the Lagrange multipliers serve as the supply capacity reserve prices, to balance the demand and supply of capacities. To prevent cyclic behaviour and to increase convergence speed, we …

A Sentiment Analysis Of Singapore Presidential Election 2011 Using Twitter Data With Census Correction, Murphy Junyu Choy, Michelle Lee Fong Cheong, Nang Laik Ma, Ping Shung Koo

Research Collection School Of Computing and Information Systems

Sentiment analysis is a new area in text analytics where it focuses on the analysis and understanding of the human emotions from the text patterns. This new form of analysis has been widely adopted in customer relationship management especially in the context of complaint management. However, sentiment analysis using Twitter data has remained extremely difficult to manage due to sampling biasness. In this paper, we will discuss about the application of reweighting techniques in conjunction with online sentiment divisions to predict the vote percentage that individual presidential candidate in Singapore will receive in the Presidential Election 2011. There will be …

Robust Local Search For Solving Rcpsp/Max With Durational Uncertainty, Na Fu, Hoong Chuin Lau, Pradeep Varakantham, Fei Xiao

Research Collection School Of Computing and Information Systems

Scheduling problems in manufacturing, logistics and project management have frequently been modeled using the framework of Resource Constrained Project Scheduling Problems with minimum and maximum time lags (RCPSP/max). Due to the importance of these problems, providing scalable solution schedules for RCPSP/max problems is a topic of extensive research. However, all existing methods for solving RCPSP/max assume that durations of activities are known with certainty, an assumption that does not hold in real world scheduling problems where unexpected external events such as manpower availability, weather changes, etc. lead to delays or advances in completion of activities. Thus, in this paper, our …

Consumer-Driven Innovation Management, Arcot Desai Narasimhalu, Shekhar Mitra

Research Collection School Of Computing and Information Systems

The evolution of human society leads to increased affluence and prosperity of certain populations, sometimes at the expense of well-established markets. Market leaders in products and services tend to be so focused on their current customer base that they are caught off guard with the changes in markets created by the evolution. These changes often go unnoticed until it is too late. The change in customer base often requires the repositioning of products and services through innovations, which address new and emerging markets. Some of these changes could potentially result in tectonic market shifts that force innovation managers to involve …

Who Is Retweeting The Tweeters? Modeling, Originating, And Promoting Behaviors In The Twitter Network, Achananuparp Palakorn, Ee Peng Lim, Jing Jiang, Tuan Anh Hoang

Research Collection School Of Computing and Information Systems

Real-time microblogging systems such as Twitter offer users an easy and lightweight means to exchange information. Instead of writing formal and lengthy messages, microbloggers prefer to frequently broadcast several short messages to be read by other users. Only when messages are interesting, are they propagated further by the readers. In this article, we examine user behavior relevant to information propagation through microblogging. We specifically use retweeting activities among Twitter users to define and model originating and promoting behavior. We propose a basic model for measuring the two behaviors, a mutual dependency model, which considers the mutual relationships between the two …

Mantle Flow And Lithosphere-Asthenosphere Coupling Beneath The Southwestern Edge Of The North American Craton: Constraints From Shear-Wave Splitting Measurements, Hesham A. Refayee

Doctoral Dissertations

"High-quality broadband seismic data recorded by the USArray and other stations in the southwestern United States provide a unique opportunity to test different models of anisotropy-forming mechanisms in the vicinity of a cratonic edge. Systematic spatial variations of anisotropic characteristics are revealed by 3027 pairs of splitting parameters measured at 547 broadband seismic stations. The western and southern edges of the North American craton show edge-parallel fast directions with larger-than-normal splitting times, and the continental interior is characterized by smaller splitting times spatially consistent fast directions that are mostly parallel to the absolute plate motion direction of North America. Except …

N-Acetyl-L-Cysteine Amide Protects Retinal Pigment Epithelium Against Methamphetamine-Induced Oxidative Stress, Nuran Ercal, Joshua W. Carey, Shakila Tobwala, Xinsheng Zhang, Atrayee Banerjee, Eylem Y. Pinarci, Humeyra Karacal

Chemistry Faculty Research & Creative Works

Methamphetamine (METH), a highly addictive drug used worldwide, induces oxidative stress in various animal organs. Recent animal studies indicate that methamphetamine also induces oxidative stress in the retina, which is an em- bryonic extension of the forebrain. The aim of this study, therefore, was to evaluate the pro- tecttive effects of N-acetylcysteine amide (NACA) against oxidative stress induced by METH in retinal pigment epithelium (RPE) cells. Our stud- ies showed that NACA protected against METH- induced oxidative stress in retinal pigment epithelial cells. Although METH significantly de- creased glutathione (GSH) levels and increased reactive oxygen species (ROS) and malondial- dehyde …

Noncanonical Reactions Of Flavoenzymes, Pablo Sobrado

Chemistry Faculty Research & Creative Works

Enzymes containing flavin cofactors are predominantly involved in redox reactions in numerous cellular processes where the protein environment modulates the chemical reactivity of the flavin to either transfer one or two electrons. Some flavoenzymes catalyze reactions with no net redox change. In these reactions, the protein environment modulates the reactivity of the flavin to perform novel chemistries. Recent mechanistic and structural data supporting novel flavin functionalities in reactions catalyzed by chorismate synthase, type II isopentenyl diphosphate isomerase, UDP-galactopyranose mutase, and alkyl-dihydroxyacetone phosphate synthase are presented in this review. In these enzymes, the flavin plays either a direct role in acid/base …

Ace - A Model Centered Reu Program Standing On The Three Legs Of Cse: Analysis, Computation And Experiment, Hong P. Liu, Andrei Ludu

Publications

Enhancing REU (research experience for undergraduates) has become a popular strategy for many selective universities to enhance quality of undergraduate education and recruit gifted new students. The university that the authors are affiliated has set REU as one of the major outcomes for our QEP (quality enhancement program) for next 5 years. This paper presents a model centered REU program entitled as ACE standing for Analysis, Computation and Experiment. As a work in progress, the program is planned to run for the next 5 years and to serve for 20-30 undergraduate students who are gifted in mathematics and computing annually. …

Transmission Scheduling Based On A New Conflict Graph Model For Multicast In Multihop Wireless Networks, Maggie Cheng, Quanmin Ye

Computer Science Faculty Research & Creative Works

In multicast applications, the end-to-end delay from the source to a group member is determined by the multicast tree topology and the waiting time at each relay node. This paper addresses when the multicast tree is given how to schedule wireless nodes for transmission so that network delay is minimized. We first model the conflict relation among wireless transmissions in a conflict graph, and then we compute a transmission schedule based on an Integer Linear Programming (ILP) model. Since solving ILP problem is NP-hard, a heuristic is designed to solve the ILP problem. the resulting schedule is conflict-free, which is …

Sieve Bootstrap Based Prediction Intervals And Unit Root Tests For Time Series, Maduka Rupasinghe

Doctoral Dissertations

"The application of the sieve bootstrap procedure, which resamples residuals obtained by fitting a finite autoregressvie (AR) approximation to empirical time series, to obtaining prediction intervals for integrated, long-memory, and seasonal time series as well as constructing a test for seasonal unit roots, is considered. The advantage of this resampling method is that it does not require knowledge about the underlying process generating a given time series and has been shown to work well for ARMA processes. We extend the application of the sieve bootstrap to ARIMA and FARIMA processes. The asymptotic properties of the sieve bootstrap prediction intervals for …

Investigation Of Biomarkers For Noninvasive Early Diagnosis Of Cancer, Sanjeewa Bandara Gamagedara

Doctoral Dissertations

"Cancer is the second leading cause of death worldwide, and deaths from cancer worldwide are projected to continue rising, with an estimated 12 million deaths in 2030. Cancer occurs when cells in a part of the body begin to grow out of control. It develops very rapidly, and early diagnosis offers a greater chance of successful treatment and a higher survival rate. Biomarkers are good potential tools for early diagnosis. The main hypothesis of this study is that the levels of certain metabolites present in human urine can indicate the current or future behavior of cancer. Therefore, these studies focused …

An Algebraic Classification Of Entangled States, Roman V. Buniy, Thomas W. Kephart

Mathematics, Physics, and Computer Science Faculty Articles and Research

We provide a classification of entangled states that uses new discrete entanglement invariants. The invariants are defined by algebraic properties of linear maps associated with the states. We prove a theorem on a correspondence between the invariants and sets of equivalent classes of entangled states. The new method works for an arbitrary finite number of finite-dimensional state subspaces. As an application of the method, we considered a large selection of cases of three subspaces of various dimensions. We also obtain an entanglement classification of four qubits, where we find 27 fundamental sets of classes.

Toward Solving The Cosmological Constant Problem By Embedding, Roman V. Buniy, Thomas W. Kephart

Mathematics, Physics, and Computer Science Faculty Articles and Research

The typical scalar field theory has a cosmological constant problem. We propose a generic mechanism by which this problem is avoided at tree level by embedding the theory into a larger theory. The metric and the scalar field coupling constants in the original theory do not need to be fine-tuned, while the extra scalar field parameters and the metric associated with the extended theory are fine-tuned dynamically. Hence, no fine-tuning of parameters in the full Lagrangian is needed for the vacuum energy in the new physical system to vanish at tree level. The cosmological constant problem can be solved if …

Forensic Analysis Of Social Networking Applications On Mobile Devices, Noora Al Mutawa, Ibrahim Baggili, Andrew Marrington

All Works

The increased use of social networking applications on smartphones makes these devices a goldmine for forensic investigators. Potential evidence can be held on these devices and recovered with the right tools and examination methods. This paper focuses on conducting forensic analyses on three widely used social networking applications on smartphones: Facebook, Twitter, and MySpace. The tests were conducted on three popular smartphones: BlackBerrys, iPhones, and Android phones. The tests consisted of installing the social networking applications on each device, conducting common user activities through each application, acquiring a forensically sound logical image of each device, and performing manual forensic analysis …

Economics And Finance On Time Scales, Julius Severin Heim

Doctoral Dissertations

"This thesis consists of 6 papers that investigate models in economics and finance based on so-called dynamic equations on time scales. The first paper covers multiplier-accelerator models that can be described by linear second-order dynamic equations. The possibility of taxes as well as the possibility of foreign trade is taken into consideration. The second paper discusses cobweb models, which describe cyclical supply and demand in markets, where the supply is determined before the observation of the price. Cobweb models that can be formulated with first-order linear, second-order linear, and nonlinear dynamic equations are being considered. The third and fourth papers …

Theoretical Studies Of Few-Body Problems, Uttam Chowdhury

Doctoral Dissertations

"Heavy ion collisions with atomic and molecular targets produce many outcomes. The Schrödinger equation is not analytically soluble for more than two mutually interacting particles. As a result, theory must resort to using approximations, the validity of which is determined by comparison with experiment. This work is focused on finding better approximations to describe ionization and capture processes in proton collisions.

Proton-impact ionization of molecular hydrogen is treated as a 3-body problem. Usually the target is treated as an atomic target and the results are multiplied by an ad hoc factor to account for the molecular structure. Measured cross sections …

A Performance Comparison Of Hypervisors For Cloud Computing, Suganya Sridharan

UNF Graduate Theses and Dissertations

The virtualization of IT infrastructure enables the consolidation and pooling of IT resources so that they can be shared over diverse applications to offset the limitation of shrinking resources and growing business needs. Virtualization provides a logical abstraction of physical computing resources and creates computing environments that are not restricted by physical configuration or implementation. Virtualization is very important for cloud computing because the delivery of services is simplified by providing a platform for optimizing complex IT resources in a scalable manner, which makes cloud computing more cost effective.

Hypervisor plays an important role in the virtualization of hardware. It …

Colordots: An Intersection Analysis Resistant Graphical Password Scheme For The Prevention Of Shoulder-Surfing Attack, Jim Littleton

UNF Graduate Theses and Dissertations

In an increasingly mobile world, the combination of mobile computing devices, publicly accessible Wi-Fi hotspots, and camera phones pose a significant threat to alphanumeric passwords in public environments. Graphical passwords, introduced as an alternative to alphanumerical passwords, help prevent successful shoulder-surfing attacks – covertly observing or recording a password login session, however, most cannot prevent intersection analysis on the data collected through shoulder-surfing. ColorDots is a new graphical password scheme designed to be easy to use and learn, to prevent successful shoulder-surfing attacks, and to hinder intersection analysis. A software implementation of ColorDots is tested, and the results analyzed. This …

Improving The Knowledge-Based Expert System Lifecycle, Lucien Millette

UNF Graduate Theses and Dissertations

Knowledge-based expert systems are used to enhance and automate manual processes through the use of a knowledge base and modern computing power. The traditional methodology for creating knowledge-based expert systems has many commonly encountered issues that can prevent successful implementations. Complications during the knowledge acquisition phase can prevent a knowledge-based expert system from functioning properly. Furthermore, the time and resources required to maintain a knowledge-based expert system once implemented can become problematic. There are several concepts that can be integrated into a proposed methodology to improve the knowledge-based expert system lifecycle to create a more efficient process. These methods are …

Synthesis And Applications Of Imidazolium-Based Ionic Liquids And Their Polymer Derivatives, Woon Su Oh

Doctoral Dissertations

"Imidazolium-based ionic liquids have been increasingly used as green solvents to replace the volatile and relatively toxic organic solvents, in homogeneous and heterogeneous catalysis, materials science, nano materials, lithium ion batteries, and separation technology. Section 1 describes the modulating effect of the imidazolium based room temperature ionic liquids (RTILs) on the critical micelle concentrations (CMC) of surfactants. CMC of sodium dodecyl sulfate (SDS), an anionic surfactant, has been investigated in aqueous solutions of a variety of room temperature ionic liquids (RTILs). CMC values decrease with increasing alkyl chain-length and with fluorinated side chains on the imidazole moiety. In section 2, …