Physical Sciences and Mathematics Commons^™

The Role Of Adenine In Fast Excited-State Deactivation Of Fad: A Femtosecond Mid-Ir Transient Absorption Study, Guifeng Li, Ksenija D. Glusac

Chemistry Faculty Publications

We present a study of excited-state dynamics of two flavin cofactors: flavin-adenine dinucleotide (FAD) and flavin-mononucleotide (FMN). We used femtosecond mid-R transient absorption spectroscopy to study the effect of FAD conformation oil its excited-state behavior. The conformation of FAD was modulated by changing the solvent polarity: in D(2)O, FAD is present predominantly in the "stacked" conformation, in which flavin and adenine moieties are in close proximity to each other, whereas the increased amount of DMSO led to an increased amount of the "open" conformer. FMN served as a model system which lacks adenine. We found that the "stacked" conformer undergoes …

Probing Single-Molecule Interfacial Geminate Electron-Cation Recombination Dynamics, Yuanmin Wang, Xuefei Wang, H. Peter Lu

Chemistry Faculty Publications

Interfacial electron-cation recombination in zinc-tetra (4-carboxyphenyl) porphyrin (ZnTCPP)/TiO(2) nanoparticle system has been probed at the single-molecule level by recording and analyzing photon-to-photon pair times of the ZnTCPP fluorescence. We have. developed a novel approach to reveal the hidden single-molecule interfacial electron-cation recombination dynamics by analyzing the autocorrelation function and a proposed convoluted single-molecule interfacial electron-cation recombination model. Our results suggest that the fluctuations of the interfacial electron transfer (ET) reactivity modulate the ET cycles as well as the interfacial electron-cation recombination dynamics. On the basis of this model, the single-molecule electron-cation recombination time of ZnTCPP/-TiO(2) system is deduced to be …

Fluorenylidene-Pyrroline Biomimetic Light-Driven Molecular Switches, Laura Rivado-Casas, Diego Sampedro, Pedro J. Campos, Stefania Fusi, Vinicio Zanirato, Massimo Olivucci

Chemistry Faculty Publications

A new family of biomimetic photoactivated molecular switches based in the retinal chromophore is described. Expedient synthesis allows a library of compounds with a different substitution pattern, including chiral substituents, to be obtained. The effect of substitution, solvent, and light source on the photoisomerization step has been assessed. The absorption maximum has been red-shifted ca. 50 nm with respect to related systems and rotation is now easily achieved by using visible light.

Assessing Organic Matter Breakdown And Associated Macroinvertebrate Community Structure In Headwater Streams: Effects Of Hydrologic Gradients And Upland Timber Harvesting, Miller Scott Jarrell

Masters Theses & Specialist Projects

I examined the effects of hydrologic gradients and upland timber harvesting with different streamside management zone widths on yellow-poplar (Liriodendron tulipifera) processing and the associated macroinvertebrate community structure in the Cumberland Plateau ecophysic region, U.S.A. Prior to upland timber harvesting, 5.0 ± 0.1 g yellow-poplar leaf packs were constructed, zip-tied to gutter nails, and placed into 7 perennial and 6 temporary stream reaches with similar physiochemical and geomorphic characteristics. From December 2007 to May 2008, 3–5 leaf packs were collected per reach monthly. I found significant differences in the functional feeding group composition. Temporary reaches contained higher shredder, gathering-collector, predator, …

Modeling Stormwater Pollutant Transport In A Karst Region--Bowling Green, Kentucky, Allison H. Ross

Masters Theses & Specialist Projects

The management of stormwater runoff is a particular challenge for communities in karst regions. Most guidelines for compliance with regulations for stormwater monitoring and mapping pertain to non-karst environments. It can be argued that effective stormwater management is even more essential to karst regions because stormwater receives little or no natural filtration as it is transferred through conduits in the subsurface and the buildup of pollutants underneath can be detrimental to community and environmental health if not effectively mitigated. Because of the limited resources available to determine how stormwater runoff carries potential pollutants across the surface before being transferred to …

Feeding Phishers, Nicholas J. Lynch

Master's Theses

Phishing campaigns continue to deceive users into revealing their credentials, despite advancing spam filters, browser and toolbar warnings, and educational efforts. Recently, researchers have begun investigating how fake credentials --- or honeytokens --- can be used to detect phishing sites and protect users. BogusBiter, one such work, creates sets of honeytokens based on users' real credentials and sends them alongside real user submissions to phishing sites. In this paper, we present Phish Feeder, an anti-phishing tool which extends the BogusBiter honeytoken generation algorithm in order to create more realistic and authentic-looking credentials. Phish Feeder also employs a ``honeytoken repository'' which …

Time Valuation Of Risk A Delayed-Bang Approach, Abhishek Pathak

Engineering Management & Systems Engineering Theses & Dissertations

The subject of this thesis is the combined use of engineering economics and survival analysis in estimating time-value of risk-related resources. The discussion includes (1) the need for sustainable risk management, (2) the importance of time-valuation of risk related resources in the allocation or selection among competing risk mitigation alternatives, (3) the convergence of deterministic engineering economics, survivability analysis, and probabilistic analysis, and (4) results and examples of application in the context of prevention of risk event or mitigation of its consequences.

The significance of this thesis is in how three topics: engineering economics, survivability analysis, and probability theory can …

Finding Alternatives To The Hard Disk Drive For Virtual Memory, Bruce Albert Embry

Theses and Dissertations

Current computer systems fill the demand of operating systems and applications for ever greater amounts of random access memory by paging the least recently used data to the hard disk drive. This paging process is called "virtual memory," to indicate that the hard disk drive is used to create the illusion that the computer has more random access memory than it actually has. Unfortunately, the fastest hard disk drives are over five orders of magnitude slower than the DRAM they are emulating. When the demand for memory increases to the point that processes are being continually saved to disk and …

Analysis Of Partial Discharge Pulse Height Distribution Parameters, Vinay N. Nimbole

Electrical & Computer Engineering Theses & Dissertations

Partial Discharges (PD) have been traditionally used to assess the state of any insulation system and its remnant life. In earlier work, Perspex (PMMA) samples with a needle plane gap have been aged with AC voltage. Their tree growth was monitored simultaneously by collecting PD at regular intervals of time and taking microphotographs in real time without interrupting the aging voltage. The obtained partial discharge pulse amplitude records were clustered together into groups of class intervals. The sequence of PD pulse height records was quantified as a time series of shape (η), and scale (σ) parameters of a Weibull distribution. …

Brain Tumor Progression Assessment Using Multiple Mri Volumes, Yufei Shen

Electrical & Computer Engineering Theses & Dissertations

Predicting and assessing tumor progression is important in brain tumor treatment. We attempt to use machine learning techniques to achieve consistency in assessing brain tumor progression. This thesis presents a prediction method of brain tumor progression by exploring a large MR database, which contains two patients ' complete records covering all their visits in the past two years. All ten MRI series, namely, apparent diffusion coefficient (ADC) , diffusion tensor imaging (DTI) , fractional anisotropy (FA), fluid attenuated inversion recovery (FLAIR), max eigenvalue (MAX), mid eigenvalue (MID), min eigenvalue (MIN) , post-contrast T₁-weighted, T₁- weighted, and …

A Study Of Decision Analysis Methods In Aerospace Technology Assessments, Sharon Monica Jones

Engineering Management & Systems Engineering Theses & Dissertations

Managers of aerospace technology programs and projects are faced with the challenge of making technology portfolio decisions under conditions of limited data, rapidly changing macro level factors and organizational uncertainties. To help make these technology investment decisions, some aerospace managers and analysts have used techniques from the field of decision analysis. In addition, there have been a limited number of research studies of real decision problems.

This dissertation presents the results of a non-experimental examination of the use of decision analysis methods for the assessment of aerospace technology portfolios. A web-based survey instrument was developed based on the results of …

Poster Abstract: Beamcast: Harnessing Beamforming Capabilities For Link Layer Multicast, Souvik Sen, Rahul Ghosh, Jie Xiong, Romit Roy Choudhury

Research Collection School Of Computing and Information Systems

Wireless multicast is an important service primitive for emerging applications such as live video, streaming audio and content telecasts. Transmission rate in such a link layer multicast is bottlenecked by the rate of the weakest client, leading to channel under-utilization. Attempts to increase the data rate results in lower reliability (due to higher bit error rate) and higher unfairness. This poster utilizes smart beamforming antennas to improve multicast performance in wireless LANs. The main idea is to satisfy majority of the (strong) clients with a high-rate omnidirectional transmission, followed by high-rate directional transmission(s) to cover the weaker ones. By selecting …

Creating Human-Like Autonomous Players In Real-Time First Person Shooter Computer Games, Di Wang, Budhitama Subagdja, Ah-Hwee Tan, Gee-Wah Ng

Research Collection School Of Computing and Information Systems

This paper illustrates how we create a software agent by employing FALCON, a self-organizing neural network that performs reinforcement learning, to play a well-known first person shooter computer game known as Unreal Tournament 2004. Through interacting with the game environment and its opponents, our agent learns in real-time without any human intervention. Our agent bot participated in the 2K Bot Prize competition, similar to the Turing test for intelligent agents, wherein human judges were tasked to identify whether their opponents in the game were human players or virtual agents. To perform well in the competition, an agent must act like …

Conditional Proxy Broadcast Re-Encryption, Cheng-Kang Chu, Jian Weng, Sherman S. W. Chow, Jianying Zhou, Robert H. Deng

Research Collection School Of Computing and Information Systems

A proxy re-encryption (PRE) scheme supports the delegation of decryption rights via a proxy, who makes the ciphertexts decryptable by the delegatee. PRE is useful in various applications such as encrypted email forwarding. In this paper, we introduce a more generalized notion of conditional proxy broadcast re-encryption (CPBRE). A CPBRE scheme allows Alice to generate a re-encryption key for some condition specified during the encryption, such that the re-encryption power of the proxy is restricted to that condition only. This enables a more fine-grained delegation of decryption right. Moreover, Alice can delegate decryption rights to a set of users at …

Geologic Storage Of Sour Co2 From A Natural Gas-Processing Plant – A Commercial Demonstration, University Of North Dakota. Energy And Environmental Research Center

EERC Brochures and Fact Sheets

Fact sheet about the Plains CO₂ Reduction (PCOR) and Spectra Energy-led demonstration of carbon capture and storage (CCS) to manage the CO₂ emissions of natural gas processing facilities. Describes the project, research objectives, and intended schedule.

Introducing Computing Now, George K. Thiruvathukal

Computer Science: Faculty Publications and Other Works

One of Computing Now's editorial board members talks about this IEEE Computer Society initiative and all that it has to offer members and nonmembers alike.

Ligand-Dependent Effects On The Conformational Equilibrium Of The Na+,K+-Atpase As Monitored By Voltage Clamp Fluorometry, Robert Dempski, Stefan Geys, Ernst Bamberg

Robert E. Dempski

Voltage clamp fluorometry was used to monitor conformational changes associated with electrogenic partial reactions of the Na(+),K(+)-ATPase after changes in the concentration of internal sodium (Na(+)(i)) or external potassium (K(+)(o)). To probe the effects of the Na(+)(i) concentration on the Na(+) branch of the Na(+),K(+)-ATPase, oocytes were depleted of Na(+)(i) and then loaded with external sodium (Na(+)(o)) using the amiloride-sensitive epithelial sodium channel. The K(+) branch of the Na(+),K(+)-ATPase was studied by exposing the oocytes to different K(+)(o) concentrations in the presence and absence of Na(+)(o) to obtain additional information on the apparent affinity for K(+)(o). Our results demonstrate that …

Design Of Service Component Layer In Soa Reference Architecture, Liang-Jie Zhang, Jia Zhang

Jia Zhang

No abstract provided.

The Primary Noise Sources Associated With Turbulent Coanda Wall Jets, Caroline Lubert

Caroline P Lubert

No abstract provided.

The Study Of The 1s4–2pj Optogalvanic Transients In A Neon Discharge Plasma, Naveed Piracha, R. Feaver, T. Gilani, Rizwan Ahmed, R. Ali, M. Baig

Naveed K. Piracha

Time dependent optogalvanic signals induced by the 1s4→2pj laser excitations have been studied in neon DC plasma. The decay rates related to all the four 1si levels have been derived by fitting the waveforms with a mathematical rate equation model. The temporal signatures of three transitions namely 638.3, 650.7 and 724.5nm related to the 2p7, 2p8 and 2p10 upper levels, respectively, have been found to be different from the rest of the transitions. We relate these effects to the population redistribution of decaying channels and to the processes responsible for the optogalvanic effect.

Collaborative Scientific Workflows, Shiyong Lu, Jia Zhang

Jia Zhang

In recent years, a number of scientific workflow management systems (SWFMSs) have been developed to help domain scientists synergistically integrate distributed computations, datasets, and analysis tools to enable and accelerate scientific discoveries. As more scientific research projects become collaborative in nature, there is a compelling need of dedicated services to support collaborative scientific workflows on the Internet. This paper reviews the state of the art of the field of scientific workflows towards the support of collaborative scientific workflows, identifies critical research challenges, and presents our ongoing research work aiming to study how to create services supporting collaborative scientific workflows.

The Biscayne Aquifer Of Southeastern Florida, Kevin Cunningham, Lee J. Florea

Lee J Florea, PhD, P.G.

In southeastern Florida, locally delineated, small, poorly explored caves and subtle karst are characteristic of the limestone that composes the unconfined Biscayne aquifer – one of the most permeable aquifers in the world. The main units of the Biscayne aquifer are the Fort Thompson Formation and Miami Limestone, both characterized by eogenetic karst.

Developing Large-Scale Bayesian Networks By Composition: Fault Diagnosis Of Electrical Power Systems In Aircraft And Spacecraft, Ole J. Mengshoel, Scott Poll, Tolga Kurtoglu

Ole J Mengshoel

In this paper, we investigate the use of Bayesian networks to construct large-scale diagnostic systems. In particular, we consider the development of large-scale Bayesian networks by composition. This compositional approach reflects how (often redundant) subsystems are architected to form systems such as electrical power systems. We develop high-level specifiations, Bayesian networks, clique trees, and arithmetic circuits representing 24 different electrical power systems. The largest among these 24 Bayesian networks contains over 1,000 random variables. Another BN represents the real-world electrical power system ADAPT, which is representative of electrical power systems deployed in aerospace vehicles. In addition to demonstrating the scalability …

Diagnosis And Reconfiguration Using Bayesian Networks: An Electrical Power System Case Study, W. Bradley Knox, Ole J. Mengshoel

Ole J Mengshoel

Automated diagnosis and reconfiguration are important computational techniques that aim to minimize human intervention in autonomous systems. In this paper, we develop novel techniques and models in the context of diagnosis and reconfiguration reasoning using causal Bayesian networks (BNs). We take as starting point a successful diagnostic approach, using a static BN developed for a real-world electrical power system. We discuss in this paper the extension of this diagnostic approach along two dimensions, namely: (i) from a static BN to a dynamic BN; and (ii) from a diagnostic task to a reconfiguration task.

More specifically, we discuss the auto-generation of …

Nevada Interagency Volunteer Program: Helping Hands Across Public Lands – Phase Ii: Annual Progress Report, Period Covering July 1, 2008 - June 30, 2009, Margaret N. Rees

Get Outdoors Nevada

• From July 1, 2008 to June 30, 2009 the Volgistic database has increased the number of records by 20% containing a total 6,226 records at the end of this period.
• Website activity this year averaged 63,590 hits per month, with an average of 5,290 pages viewed per month.
• The IVP team presented a summary of their accomplishments to the SNAP board.
• The team attended 13 community outreach events resulting in 2,501 direct contacts and 394 new mailing list records.
• How to Succeed with Volunteers training was held for SNAP personnel.
• The IVP team met with four SNAP teams to develop …

Back Matter

Journal of Digital Forensics, Security and Law

No abstract provided.

Masthead

Journal of Digital Forensics, Security and Law

No abstract provided.

Front Matter

Journal of Digital Forensics, Security and Law

No abstract provided.

Radio Determination On Mini-Uav Platforms: Tracking And Locating Radio Transmitters, Braden Russell Huber

Theses and Dissertations

Aircraft in the US are equipped with Emergency Locator Transmitters (ELTs). In emergency situations these beacons are activated, providing a radio signal that can be used to locate the aircraft. Recent developments in UAV technologies have enabled mini-UAVs (5-foot wingspan) to possess a high level of autonomy. Due to the small size of these aircraft they are human-packable and can be easily transported and deployed in the field. Using a custom-built Radio Direction Finder, we gathered readings from a known transmitter and used them to compare various Bayesian reasoning-based filtering algorithms. Using a custom-developed simulator, we were able to test …

Recovery Time Scales In A Reversed-Biased Quantum Dot Absorber, T. Piwonski, Gillian Madden, Jaroslaw Pulka, Guillaume Huyet, Et. Al.

Physical Sciences Publications

The nonlinear recovery of quantum dot based reverse-biased waveguide absorbers is investigated both experimentally and analytically. We show that the recovery dynamics consists of a fast initial layer followed by a relatively slow decay. The fast recovery stage is completely determined by the intradot properties, while the slow stage depends on the escape from the dot to the wetting layer.