Physical Sciences and Mathematics Commons^™

Transcending Technological Innovation: The Impact Of Acquisitions On Entrepreneurial Technical Organizations, Bruce Crochetiere

Walden Dissertations and Doctoral Studies

Technology firms with substantial cash reserves acquire smaller entrepreneurial firms for diversification. In 2006, 3 large firms acquired 28 organizations, with the combined deals exceeding {dollar}4.7 billion. The problem addressed in this study is that new start-up companies with innovative ideas may not mature when they are acquired by larger companies and do not fully articulate potential industry-transcending innovation. This is important because the unsuccessful integration of an acquisition can dismantle innovation and compromises economic inventiveness. Drawing from the disruptive innovation and the resource-based theories, the purpose of the quasi-experimental study was to examine the impact of acquisition by larger …

Biologically Active Alkaloids From Kopsia., Yap Wai Sum

Student Works (2010-2019)

Two Malaysian plants viz., Kopsia pauciflora and Kopsia grandifolia were investigated for their alkaloidal constituents. A total of 40 alkaloids were isolated and characterized from K. pauciflora, of which 12 are new alkaloids. The new alkaloids isolated include seven aspidofractinine alkaloids (1, 2, 3, 4, 5, 6, 7), and five eburnane alkaloids (8, 9, 10, 11, 12). K. grandifolia yielded a total of eight alkaloids. Of these, three are new. The new alkaloids are grandilodine A (41), grandilodine B (42), and grandilodine C (43). Grandilodine A (41), grandilodine C (43), and lapidilectine B (47) were found to reverse multidrug resistance …

Instance-Based Parameter Tuning Via Search Trajectory Similarity Clustering, Linda Lindawati, Hoong Chuin Lau, David Lo

Research Collection School Of Computing and Information Systems

This paper is concerned with automated tuning of parameters in local-search based meta-heuristics. Several generic approaches have been introduced in the literature that returns a ”one-size-fits-all” parameter configuration for all instances. This is unsatisfactory since different instances may require the algorithm to use very different parameter configurations in order to find good solutions. There have been approaches that perform instance-based automated tuning, but they are usually problem-specific. In this paper, we propose CluPaTra, a generic (problem-independent) approach to perform parameter tuning, based on CLUstering instances with similar PAtterns according to their search TRAjectories. We propose representing a search trajectory as …

Lightweight Delegated Subset Test With Privacy Protection, Xuhua Zhou, Xuhua Ding, Kefei Chen

Research Collection School Of Computing and Information Systems

Delegated subset tests are mandatory in many applications, such as content-based networks and outsourced text retrieval, where an untrusted server evaluates the degree of matching between two data sets. We design a novel scheme to protect the privacy of the data sets in comparison against the untrusted server, with half of the computation cost and half of the ciphertext size of existing solutions based on predicate only encryption supporting inner product.

Trends And Controversies: Ai, Virtual Worlds, And Massively Multiplayer Online Games, Hsinchun Chen, Yulei Zhang, W. S. Bainbridge, Kyong Jin Shim, N. Pathak, M. A. Ahmad, C. Delong, Z. Borbora, A. Mahapatra, J. Srivastava

Research Collection School Of Computing and Information Systems

The rich social media data generated in virtual worlds has important implications for business, education, social science, and society at large. Similarly, massively multiplayer online games (MMOGs) have become increasingly popular and have online communities comprising tens of millions of players. They serve as unprecedented tools for theorizing about and empirically modeling the social and behavioral dynamics of individuals, groups, and networks within large communities. Some technologists consider virtual worlds and MMOGs to be likely candidates to become the Web 3.0. AI can play a significant role, from multiagent avatar research and immersive virtual interface design to virtual world and …

Innovation And Price Competition In A Two-Sided Market, Mei Lin, Shaojin Li, Andrew B. Whinston

Research Collection School Of Computing and Information Systems

We examine a platform's optimal two-sided pricing strategy while considering seller-side innovation decisions and price competition. We model the innovation race among sellers in both finite and infinite horizons. In the finite case, we analytically show that the platform's optimal seller-side access fee fully extracts the sellers' surplus, and that the optimal buyer-side access fee mitigates price competition among sellers. The platform's optimal strategy may be to charge or subsidize buyers depending on the degree of variation in the buyers' willingness to pay for quality; this optimal strategy induces full participation on both sides. Furthermore, a wider quality gap among …

Receiver Function Studies Of Crustal Structure, Composition, And Evolution Beneath The Afar Depression, Ethiopia, Sattam A. Almadani

Doctoral Dissertations

"The dissertation utilizes a set of sophisticated computer programs developed at the Geophysics group at Missouri S&T to characterize crustal properties beneath the Afar Depression in Ethiopia where extensional tectonics dominates. In this study, measurements of crustal thickness (H), crustal mean Vp/Vs [which is related to Poisson's ratio (Σ)], and the sharpness of the Moho (R) were determined using teleseismic data from 18 broadband seismic sensors that we deployed along a profile of 250 km long with a station spacing of ~ 10 km. The stations had been recording continuously for an entire year from December 2009 until December 2010. …

A Moving-Object Index For Efficient Query Processing With Peer-Wise Location Privacy, Dan Lin, Christian S. Jensen, Rui Zhang, Lu Xiao, Jiaheng Lu

Computer Science Faculty Research & Creative Works

With the growing use of location-Based services, location privacy attracts increasing attention from users, industry, and the research community. While considerable effort has been devoted to inventing techniques that prevent service providers from knowing a user's exact location, relatively little attention has been paid to enabling so-called peer-wise privacy-the protection of a user's location from unauthorized peer users. This paper identifies an important efficiency problem in existing peer-privacy approaches that simply apply a filtering step to identify users that are located in a query range, but that do not want to disclose their location to the querying peer. to solve …

Clustering Web Video Search Results Based On Integration Of Multiple Features, Alex Hindle, Jie Shao, Dan Lin, Jiaheng Lu, Rui Zhang

Computer Science Faculty Research & Creative Works

The usage of Web video search engines has been growing at an explosive rate. Due to the ambiguity of query terms and duplicate results, a good clustering of video search results is essential to enhance user experience as well as improve retrieval performance. Existing systems that cluster videos only consider the video content itself. This paper presents the first system that clusters Web video search results by fusing the evidence from a variety of information sources besides the video content such as title, tags and description. We propose a novel framework that can integrate multiple features and enable us to …

Differential Geometry Of Moving Surfaces And Its Relation To Solitons, Andrei Ludu

Publications

In this article we present an introduction in the geometrical theory of motion of curves and surfaces in R 3 , and its relations with the nonlinear integrable systems. The working frame is the Cartan’s theory of moving frames together with Cartan connection. The formalism for the motion of curves is constructed in the Serret-Frenet frames as elements of the bundle of adapted frames. The motion of surfaces is investigated in the Gauss-Weingarten frame. We present the relations between types of motions and nonlinear equations and their soliton solutions.

Solitary Waves, Periodic And Elliptic Solutions To The Benjamin, Bona & Mahony (Bbm) Equation Modified By Viscosity, S.C. Mancas, Harihar Khanal, Shahrdad G. Sajjadi

Publications

We introduce spatiotemporal solitons of the two-dimensional complex Ginzburg-Landau equation (2D CCQGLE) with cubic and quintic nonlinearities in which asymmetry between space-time variables is included. The 2D CCQGLE is solved by a powerful Fourier spectral method, i.e., a Fourier spatial discretization and an explicit scheme for time differencing. Varying the system’s parameters, and using different initial conditions, numerical simulations reveal 2D solitons in the form of stationary, pulsating and exploding solitons which possess very distinctive properties. For certain region of parameters, we have also found stable coherent structures in the form of spinning (vortex) solitons which exist as a result …

Development Of A Versatile Man-Portable Obscurant Aerosol Generator: Characterization Of Aerosols In Laboratory And Field Environments, Robert William Schaub

Doctoral Dissertations

"The objective of research presented in this dissertation was to develop a readily deployable and environmentally benign obscurant system operating with a single liquid for the visible and near infrared regions. To achieve this objective, research efforts were directed in two areas: i. Evaluating suitable biogenic oils to replace the United States Army's "Fog Oil" as the obscurant fluid. ii. Design, fabrication and validation of a prototype man-portable / vehicle mountable modular obscurant aerosol generator. Petroleum middle distillate - "Fog Oil" has been the material of choice for wide area obscuration for several decades. Large quantities (thousands gallons) of the …

Synthesis And Binding Studies Of Peptide Mimetics, Anion Receptors, And Kinase Inhibitors, Nanditha G. Nair

Doctoral Dissertations

"A series of novel purine-based fluoroaryl triazoles were synthesized and assayed for their neuroprotective effects of hippocampal slice culture exposed to amyloid beta (Aß) oligomers. A monofluorinated triazole has been identified which has comparable neuroprotective effect as that of flavopiridol and roscovitine against the Aß induced neurotoxicity. Carnosine and histidine are biologically interesting antioxidants. In order to probe whether they exert their antioxidant effect through metal ion chelation, the Cu(ll) ion chelating abilities of these compounds were measured by UV-vis spectroscopy. Amyloid beta, the major component of senile plaques in Alzheimer's disease, is known to complex transition metal ions through …

Cat Detect (Computer Activity Timeline Detection): A Tool For Detecting Inconsistency In Computer Activity Timelines, Andrew Marrington, Ibrahim Baggili, George Mohay, Andrew Clark

All Works

The construction of timelines of computer activity is a part of many digital investigations. These timelines of events are composed of traces of historical activity drawn from system logs and potentially from evidence of events found in the computer file system. A potential problem with the use of such information is that some of it may be inconsistent and contradictory thus compromising its value. This work introduces a software tool (CAT Detect) for the detection of inconsistency within timelines of computer activity. We examine the impact of deliberate tampering through experiments conducted with our prototype software tool. Based on the …

Composite Web Services Formation Using A Social Network Of Web Services: A Preliminary Investigation, Said Elnaffar, Zakaria Maamar

All Works

A composite Web service, such as arranging a travel to a conference, can be viewed as a project team that is comprised of several members who want to collaborate in order to accomplish a specific goal. In this work, we propose an algorithm for searching a social network of Web services in order to select an effective set of Web services that can collaborate in order to attain the main goal of the composite Web service at hand. Ultimately, the selection algorithm takes into consideration the set of functions that each Web services member possesses, e.g., hotel booking, car rental, …

Real-Time Behavior-Based Robot Control, Brian G. Woolley, Gilbert L. Peterson, Jared T. Kresge

Faculty Publications

Behavior-based systems form the basis of autonomous control for many robots, but there is a need to ensure these systems respond in a timely manner. Unexpected latency can adversely affect the quality of an autonomous system’s operations, which in turn can affect lives and property in the real-world. A robots ability to detect and handle external events is paramount to providing safe and dependable operation. This paper presents a concurrent version of a behavior-based system called the Real-Time Unified Behavior Framework, which establishes a responsive basis of behavior-based control that does not bind the system developer to any single behavior …

Minimal And Near Minimal Congruence Lattice Representations Of Finite Lattices By Finite Algebras On Sets Of Integers, Roger Lee Bunn

Doctoral Dissertations

"We give finite congruence lattice representations of some finite distributive, modular and nonmodular lattices by means of finite algebras on sets of integers. These representations are minimal or near minimal as determined by ρ, a mapping from the class R of finitely representable lattices into the natural numbers N"--Abstract, page iii.

Applied Palynology: Multidisciplinary Case Studies From Egypt, Gulf Of Mexico And Usa, Mohamed K. Zobaa

Doctoral Dissertations

"Various applications of palynology have been used to study case studies from four different parts of the world, namely northern Egypt, offshore Gulf of Mexico, eastern Tennessee (USA), and New Orleans, Louisiana (USA). In these case studies, palynomorphs (spores, pollen, dinoflagellate cysts, and algae) have been utilized to define zones of hydrocarbon potential, reconstruct paleoenvironmental and paleoclimatic conditions, constrain the ages of the studied rock sequences, and express its potential as a replacement proxy for some expensive organic geochemical analyses. The ability to detect past hurricane activities and their associated damage to the geologic record is here presented as a …

A Geological And Geophysical Study Of The Tendaho Graben In The Afar Depression, Ethiopia: Insights Into Transitional Continental Rifting, David Lee Bridges

Doctoral Dissertations

"A detailed magnetic and gravity study across the Tendaho Graben (the Red Sea propagator within the Afar Depression, Ethiopia) revealed features that can best be interpreted as a continental rift undergoing oceanization. This NW-trending extensional structure is ~50 km wide and it is confined within well-developed NW-trending boarder faults that deform the 2 km thick and ~ 2 Ma basaltic flows of the Afar Stratoids. The age of the basaltic flows becomes progressively younger inward from the boarder faults until it reaches ~30,000 years close to the rift axis. The central part of the Tendaho Graben is characterized by a …

Quantum Electrodynamics And Fundamental Constants, Benedikt J. Wundt

Doctoral Dissertations

"The unprecedented precision achieved both in the experimental measurements as well as in the theoretical description of atomic bound states make them an ideal study object for fundamental physics and the determination of fundamental constants. This requires a careful study of the effects from quantum electrodynamics (QED) on the interaction between the electron and the nucleus.

The two theoretical approaches for the evaluation of QED corrections are presented and discussed. Due to the presence of two energy scales from the binding potential and the radiation field, an overlapping parameter has to be used in both the approaches in order to …

Modeling Hourly Electricity Prices: A Structural Time Series Approach Incorporating Modified Garch Innovations, Edirisinghe Mudiyanselage Asitha Edirisinghe

Doctoral Dissertations

"The main objective of this research is to develop time series based procedures for modeling day-ahead and real-time hourly electricity prices. Such empirical processes exhibit features that make the direct application of standard time series models infeasible. Four years of hourly day-ahead and real-time electricity price data from the region supplied by the American Electric Power (AEP) company through the PJM Regional Transmission Organization (RTO) and one half years of real-time electricity prices from the MISO RTO are utilized as an empirical basis for developing such procedures. The price data show several features, such as irregular seasonal behavior, weekly and …

Multiple Differential Study Of Fragmentation Processes In 75 Kev Proton-Molecular Hydrogen Collisions, Kisra Nayomal Egodapitiya

Doctoral Dissertations

"Double Differential Cross Sections (DDCS) were measured for single ionization of H₂ by 75 keV proton (p) impact as a function of the projectile scattering angle (θp) for a fixed energy loss (ΔE) for two different target-collimating slit distances, which determined the width of the projectile wave packet (Δx). In one case Δx was larger than the inter-nuclear separation of the H₂ molecule (coherent projectile beam), while for the other case it was much smaller than the inter-nuclear separation (incoherent projectile beam). A Young type interference pattern was observed in the coherent data, but this was not present in the …

First-Principles Studies Of Complex Hydrides For Li-Ion Battery And Hydrogen Storage Applications, Timothy Hudson Mason

Doctoral Dissertations

"We employ density functional theory in a computational study of two energy storage systems.

In the first, we explore the thermodynamic viability of light metal hydrides as a high capacity Li-ion battery negative electrode. Given a set of solid-state and gas-phase reactants, we have determined the phase diagram in the Li-Mg-B-N-H system in the grand canonical ensemble as a function of lithium electrochemical potential. We present computational results for several new conversion reactions with predicted capacities between 2400 and 4000 mAhg⁻¹ that are thermodynamically favorable and that do not involve gas evolution. We provide experimental evidence for the reaction pathway …

Interfacial Effects On Dielectric Properties Of Polymer-Particle Nanocomposites, Sasidhar Siddabattuni

Doctoral Dissertations

"Dielectric materials that are capable of efficiently storing large amounts of electrical energy are desirable for many electronic and power devices. Since the electrical energy density in a dielectric material is limited to εV_b²/2, where ε is the dielectric permittivity of the material and V_b is the breakdown strength, increased permittivity and breakdown strength are required for large energy storage density. Interfacial effects can influence the dielectric properties, especially dielectric breakdown resistance in polymer-particle nanocomposites. Several functional organophosphates were used to modify the surface of titania and barium titanate nanofiller particles in order to achieve covalent interface …

Ceeme: Compensating Events Based Execution Monitoring Enforcement For Cyber-Physical Systems, Thoshitha T. Gamage

Doctoral Dissertations

"Fundamentally, inherently observable events in Cyber-Physical Systems with tight coupling between cyber and physical components can result in a confidentiality violation. By observing how the physical elements react to cyber commands, adversaries can identify critical links in the system and force the cyber control algorithm to make erroneous decisions. Thus, there is a propensity for a breach in confidentiality leading to further attacks on availability or integrity. Due to the highly integrated nature of Cyber-Physical Systems, it is also extremely difficult to map the system semantics into a security framework under existing security models. The far-reaching objective of this research …

Epitaxial Electrodeposition Of Metal Oxide Films And Superlattices Which Exhibit Resistance Switching, Rakesh V. Gudavarthy

Doctoral Dissertations

"This dissertation presents an investigation of the electrodeposition of metal oxide films and superlattices on conducting polycrystalline and single crystal substrates. In the first part of the study, electrodeposition of magnetite (Fe₃O₄) films and superlattices in the magnetite/zinc ferrite system which exhibit resistance switching is studied. Paper I reports the electrodeposition of superlattices in the magnetite/zinc ferrite system and shows that only superlattices exhibit multistate resistance switching. In paper II, simple polycrystalline magnetite films electrodeposited on stainless steel crystals exhibit multistate resistance switching which can be tuned by controlling the composition of the films. Paper II describes the epitaxial electrodeposition …

Cross-Layer Design For Network Performance Optimization In Wireless Networks, Xuan Gong

Doctoral Dissertations

"In this dissertation, I use mathematical optimization approach to solve the complex network problems. Paper l and paper 2 first show that ignoring the bandwidth constraint can lead to infeasible routing solutions. A sufficient condition on link bandwidth is proposed that makes a routing solution feasible, and then a mathematical optimization model based on this sufficient condition is provided. Simulation results show that joint optimization models can provide more feasible routing solutions and provide significant improvement on throughput and lifetime. In paper 3 and paper 4, an interference model is proposed and a transmission scheduling scheme is presented to minimize …

Assessing The Usability Of A Wearable Computer Interface With Split Button Configuration, Lisa A. Jamba

UNF Graduate Theses and Dissertations

A wearable computer interface with split button configuration was constructed using Arduino Lilypad components on the front of a vest with the goal of assessing its usability in an activity involving at least one hand. A sample of twelve men and eight women ages 18 to 62 participated in a usability study of the vest. The activity chosen for this study was a typing test during which users would control a media player remotely with the vest. The usability measures included ease of use, performance of the interface as determined by accuracy rates and time to task completion for both …

Defining Routing Policies In Peer-To-Peer Overlay Networks, Michael Pickering

UNF Graduate Theses and Dissertations

This master’s thesis involves the definition and development of a policy-based routing scheme for peer-to-peer overlay networks. Many peer-to-peer networks are in existence today and each has various methods for discovering new peers, searching for content, and overcoming connectivity problems. The addition of efficient policy-based routing enhances the ability of peers within overlay networks to make appropriate routing decisions. Policy-based routing provides a means for peers to define the types of network traffic they are willing to route and the conditions under which they will route it. The motivations for these policies are many and are described in upcoming sections. …

Performance Of Bfsa Based Anti-Collision Protocols For Rfid Networks Supporting Identical Tags, Kirti Chemburkar

UNF Graduate Theses and Dissertations

Radio Frequency Identification (RFID) is a powerful emerging technology widely used for asset tracking, supply chain management, animal identification, military applications, payment systems, and access control. Over the years, RFID has emerged as a popular technology in various industries because of its ability to track moving objects. As RFID is becoming less expensive and more robust, many companies and vendors are developing tags to track objects. Multiple vendors manufacture RFID tags worldwide. Therefore, it is quite possible that they manufacture tags with the same identification code (ID) as vendor ID code data sets may not be synchronized or may be …