Physical Sciences and Mathematics Commons^™

Toxicity Assessment Of Single-Walled Carbon Nanotubes, Eva Herzog

Doctoral

The objective of this study was to investigate the potential adverse health effects of occupational exposure to SWCNT dust using various in vitro approaches. Lung epithelium (represented by A549 and NHBE cells) was chosen as target cell model and exposed to minimally processed particle samples under submerse conditions and effects were compared to that of carbon black and crocidolite asbestos exposure. Cytotoxicity studies indicated low acute cytotoxicity of SWCNT. Morphological changes included decreases in microvilli and increased numbers of surfactant storing lamellar bodies and changes in cytoskeleton. Due to interactions of SWCNT and toxicity indicator dyes, the clonogenic assay was …

Sampling With Confidence: Using K-Nn Confidence Measures In Active Learning, Rong Hu, Sarah Jane Delany, Brian Macnamee

Conference papers

Active learning is a process through which classifiers can be built from collections of unlabelled examples through the cooperation of a human oracle who can label a small number of examples selected as most informative. Typically the most informative examples are selected through uncertainty sampling based on classification scores. However, previous work has shown that, contrary to expectations, there is not a direct relationship between classification scores and classification confidence. Fortunately, there exists a collection of particularly effective techniques for building measures of classification confidence from the similarity information generated by k-NN classifiers. This paper investigates using these confidence measures …

Enabling Adaptation In Trust Computations, Luca Longo, Pierpaolo Dondio, Bresciani Riccardo, Andrew Butterfield, Stephen Barrett

Conference papers

Digital systems have been rapidly evolving within highly dynamic and unstructured environments, where the lack of a central authority forces entities to interact with each other through collaboration and negotiation. Digital agents often use Trust models in order to compute the level of trustworthiness of the partner they want to collaborate with. Unfortunately, due to the evolution speed of open and collaborative environments, the trustworthiness of an agent varies over time, and as a result, Trust models must be continuously adapted to the changing context. In this work we address the problem by presenting a self-adaptive model for Trust computations. …

Sentiment Classification Of Reviews Using Sentiwordnet, Bruno Ohana, Brendan Tierney

Conference papers

Sentiment classification concerns the use of automatic methods for predicting the orientation of subjective content on text documents, with applications on a number of areas including recommender and advertising systems, customer intelligence and information retrieval. SentiWordNet is an opinion lexicon derived from the WordNet database where each term is associated with numerical scores indicating positive and negative sentiment information. This research presents the results of applying the SentiWordNet lexical resource to the problem of automatic sentiment classification of film reviews. Our approach comprises counting positive and negative term scores to determine sentiment orientation, and an improvement is presented by building …

Evaluating Lake Response To Environmental And Climatic Change Using Lake Core Records And Modeling, Brandi Bracht-Flyr

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

This dissertation evaluates how lakes respond to changes in their environmental and climatic settings. This dissertation consists of two lake modeling projects and the environmental and paleoclimatic reconstructions of four lakes in southwestern Montana. Lakes and their associated biological communities respond to environmental and climatic change on rapid timescales. Lake modeling and lake core stratigraphies are complementary tools for exploration of how lakes and their biota respond to environmental or climatic perturbations. In one modeling approach for exploring these issues, a simple hydro-climatological lake model was developed that classifies lake sensitivity to climatic perturbations based upon lake area, catchment area, …

Fitting Weibull Acd Models To High Frequency Transactions Data : A Semi-Parametric Approach Based On Estimating Functions, Kok Haur Ng, David E. Allen, Shelton Peiris

Research outputs pre 2011

Autoregressive conditional duration (ACD) models play an important role in financial modeling. This paper considers the estimation of the Weibull ACD model using a semiparametric approach based on the theory of estimating functions (EF). We apply the EF and the maximum likelihood (ML) methods to a data set given in Tsay (2003, p203) to compare these two methods. It is shown that the EF approach is easier to apply in practice and gives better estimates than the MLE. Results show that the EF approach is compatible with the ML method in parameter estimation. Furthermore, the computation speed for the EF …

Connections Between Computation Trees And Graph Covers, Deanna Dreher, Judy L. Walker

Department of Mathematics: Faculty Publications

Connections between graph cover pseudocodewords and computation tree pseudocodewords are investigated with the aim of bridging the gap between the theoretically attractive analysis of graph covers and the more intractable analysis of iterative message-passing algorithms that are intuitively linked to graph covers. Both theoretical results and numerous examples are presented.

Field-Scale Cleanup Of Atrazine And Cyanazine Contaminated Soil With A Combined Chemical-Biological Approach, Manmeet Waria, Steven Comfort, Sathaporn Onanong, T. Satapanajaru, Hardiljeet Boparai, C. Harris, Daniel D. Snow, David A. Cassada

Nebraska Water Center: Faculty Publications

A former agrichemical dealership in western Nebraska was suspected of having contaminated soil. Our objective was to characterize and remediate the contaminated site by a combined chemical-biological approach. This was accomplished by creating contour maps of the on-site contamination, placing the top 60 cm of contaminated soil in windrows and mixing with a mechanical high-speed mixer. Homogenized soil containing both atrazine [6-chloro-N-ethyl-N´-isopropyl-1,3,5-triazine- 2,4-diamine] and cyanazine {2-[[4-chloro-6-(ethylamino)-1,3,5- triazin-2-yl] amino]-2-methylpropanenitrile} was then used in laboratory investigations to determine optimum treatments for pesticide destruction. Iron suspension experiments verified that zerovalent iron (Fe⁰) plus ferrous sulfate (FeSO_{4 …}

Estrogenic Compounds Downstream From Three Small Cities In Eastern Nebraska: Occurrence And Biological Effect, Marlo K. Sellin, Daniel D. Snow, Debbie L. Akerly, Alan S. Kolok

Nebraska Water Center: Faculty Publications

Recent studies have detected estrogenic compounds in surface waters in North America and Europe. Furthermore, the presence of estrogenic compounds in surface waters has been attributed, in some cases, to the discharge of wastewater treatment plant (WWTP) effluent. The primary objective of the current study was to determine if WWTP effluent contributes estrogens to the surface waters of Nebraska. A second objective of this study was to determine if estrogens were found in concentrations sufficient enough to manifest feminizing effects on fish. These objectives were satisfied by deploying polar organic chemical integrative samplers (POCIS) and caged fathead minnows at eight …

A Match-Based Approach To Optimize Conformance Test Sequence Generation Using Mp-Method, Jitian Xiao

Research outputs pre 2011

An important issue in protocol conformance testing is how to generate test sequences in an efficient and effective way that achieves the required fault detection coverage. We proposed an approach for finding shorter test sequences for protocol conformance testing based on the Wp method in our previous work. While the method generated good quality test sequences, an extra leading sequence may have to be added if the final test sequence generated was not started from the same starting state of the given FSM. A new approach is proposed in this paper to overcome this problem thus to improve the quality …

Scada Security - Slowly Circling A Disaster Area, Craig Valli, Andrew Woodward

Research outputs pre 2011

SCADA (Supervisory Control And Data Acquisition) networks control much of the industrialised nations production and supply complexes. Various government reports and investigations have highlighted the vulnerability of these systems. Many of these systems are on private networks which are increasingly being connected to systems that are accessible from other networks such as the Internet. SCADA systems have unique security and operational requirements. However, many of the most basic security measures are missing in these networks. This examines some of these issues and proposes some technologies that could help secure these networks from attack.

Scada Forensics With Snort Ids, Craig Valli

Research outputs pre 2011

This paper is a research in progress paper outlining an approach using open source IDS (Snort) and honeypot (nepenthes, honeyd) technologies to create a resilient layered defensive approach for SCADA and control systems networks.

Electron Attachment To Trans-Azobenzene, Alberto Modelli, Paul Burrow

Paul Burrow Publications

The temporary anion states of gas-phase trans-azobenzene are characterized by means of electron transmission spectroscopy (ETS) in the 0–6 eV range. The measured energies of vertical electron attachment are compared with the energies of the π* virtual orbitals of the neutral molecule supplied by HF (at MP2 optimized geometries) and B3LYP calculations. The calculated energies, scaled with empirical equations, reproduce quantitatively the energies of the corresponding spectral features and predict a positive vertical electron affinity of 0.83 eV.

The total anion current at the walls of the collision chamber and the mass-selected molecular anion current are also reported as …

Development Of A Source Of Quasi-Monochromatic Mev Energy Photons, Donald Umstadter, Sudeep Banerjee, Viswanathan Ramanathan, Nathan D. Powers, Nathaniel Cunningham, Nathan A. Chandler-Smith

Donald Umstadter Publications

We report current progress on a project to develop an all-optically-driven x-ray photon source. A laser pulse with 40-50 TW of peak power is focused on a supersonic helium nozzle to drive a relativistic plasma wave. Electron beams with energies of 320 MeV (+/- 28 MeV) are accelerated by means of laser wakefield acceleration. Remarkably, the acceleration region is only 3 mm in length. This accelerator is currently being employed to demonstrate the generation of MeV- energy x-ray by means of all-optical Thomson scattering. By this mechanism, a lower power, laser pulse (from the same laser system) is focused onto …

Semantics-Empowered Social Computing, Amit P. Sheth, Meenakshi Nagarajan

Kno.e.sis Publications

In this article, we discuss some of the challenges in marking-up or annotating UGC, a first step toward the realization of the social semantic Web. Using examples from real- world UGC, we show how domain knowledge can effectively complement statistical natural language processing techniques for metadata creation.

Prom: A Semantic Web Framework For Provenance Management In Science, Satya S. Sahoo, Roger Barga, Amit P. Sheth, Krishnaprasad Thirunarayan, Pascal Hitzler

Kno.e.sis Publications

The eScience paradigm is enabling researchers to collaborate over the Web in virtual laboratories and conduct experiments on an industrial scale. But, the inherent variability in the quality and trust associated with eScience resources necessitates the use of provenance information describing the origin of an entity. Existing systems often model provenance using ambiguous terminology, have poor domain semantics and include modeling inconsistencies that hinders interoperability. Further, mere collection of provenance information is of little value without a well-defined and scalable query mechanism.

In this paper, we present 'PrOM', a framework that addresses both the modeling and querying issues in eScience …

Service Level Agreement In Cloud Computing, Pankesh Patel, Ajith H. Ranabahu, Amit P. Sheth

Kno.e.sis Publications

Cloud computing that provides cheap and pay-as-you-go computing resources is rapidly gaining momentum as an alternative to traditional IT Infrastructure. As more and more consumers delegate their tasks to cloud providers, Service Level Agreements(SLA) between consumers and providers emerge as a key aspect. Due to the dynamic nature of the cloud, continuous monitoring on Quality of Service (QoS) attributes is necessary to enforce SLAs. Also numerous other factors such as trust (on the cloud provider) come into consideration, particularly for enterprise customers that may outsource its critical data. This complex nature of the cloud landscape warrants a sophisticated means of …

Characterization Of 1h Nmr Spectroscopic Data And The Generation Of Synthetic Validation Sets, Paul E. Anderson, Michael L. Raymer, Benjamin J. Kelly, Nicholas V. Reo, Nicholas J. Delraso, Travis E. Doom

Kno.e.sis Publications

Motivation: Common contemporary practice within the nuclear magnetic resonance (NMR) metabolomics community is to evaluate and validate novel algorithms on empirical data or simplified simulated data. Empirical data captures the complex characteristics of experimental data, but the optimal or most correct analysis is unknown a priori; therefore, researchers are forced to rely on indirect performance metrics, which are of limited value. In order to achieve fair and complete analysis of competing techniques more exacting metrics are required. Thus, metabolomics researchers often evaluate their algorithms on simplified simulated data with a known answer. Unfortunately, the conclusions obtained on simulated data are …

User-Generated Content On Social Media Challenges, Opportunities, Meenakshi Nagarajan

Kno.e.sis Publications

Understanding and exploiting user generated (textual) content (UGC) on social media is at the forefront of information management challenges today. The variety of UGC in detailed blog commentaries, collaborative wiki-content, online conversations, short messages in micro-blogs etc., are powering several personalization, monetization, crowd/business intelligence applications, and also providing an electronic microscope on social phenomena at an extraordinary scale. Certain characteristics of UGC however, necessitate key computational linguistic interventions before systems can tap into this data. A large portion of language found on social media is in the Informal English domain a blend of abbreviations, slang and context dependent terms delivered …

Determining The Best K For Clustering Transactional Datasets: A Coverage Density-Based Approach, Hua Yan, Keke Chen, Ling Liu

Kno.e.sis Publications

The problem of determining the optimal number of clusters is important but mysterious in cluster analysis. In this paper, we propose a novel method to find a set of candidate optimal number Ks of clusters in transactional datasets. Concretely, we propose Transactional-cluster-modes Dissimilarity based on the concept of coverage density as an intuitive transactional inter-cluster dissimilarity measure. Based on the above measure, an agglomerative hierachical clustering algorithm is developed and the Merge Dissimilarity Indexes, which are generated in hierachical cluster merging processes, are used to find the candidate optimal number Ks of clusters of transactional data. Our experimental results on …

Prediction Of A Spin-Polarized Two-Dimensional Electron Gas At The Laalo3/Euo(001) Interface, Yong Wang, Manish K. Niranjan, John D. Burton, Joonhee M. An, Kirill D. Belashchenko, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

First-principles calculations predict the existence of a spin-polarized two-dimensional electron gas (2DEG) at the LaO/EuO interface in a LaAlO₃/EuO(001) heterostructure. This polar interface favors electron doping into the Eu-5d conduction bands resulting in a 2DEG formed at the interface.

Prediction Of Electrically Induced Magnetic Reconstruction At The Manganite/Ferroelectric Interface, John D. Burton, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

The control of magnetization via the application of an electric field, known as magnetoelectric coupling, is among the most fascinating and active research areas today. In addition to fundamental scientific interest, magnetoelectric effects may lead to new device concepts for data storage and processing. There are several known mechanisms for magnetoelectric coupling that include intrinsic effects in single-phase materials, strain-induced coupling in two-phase composites, and electronically driven effects at interfaces. Here we explore a different type of magnetoelectric effect at a ferromagnetic-ferroelectric interface: magnetic reconstruction induced by switching of electric polarization.

Prediction Of A Switchable Two-Dimensional Electron Gas At Ferroelectric Oxide Interfaces, Manish K. Niranjan, Yong Wang, Sitaram S. Jaswal, Evgeny Y. Tsymbal

Evgeny Tsymbal Publications

The demonstration of a quasi-two-dimensional electron gas (2DEG) in LaAlO₃=SrTiO₃ heterostructures has stimulated intense research activity in recent years. The 2DEG has unique properties that are promising for applications in all-oxide electronic devices. For such applications it is desirable to have the ability to control 2DEG properties by external stimulus. Here, based on first-principles calculations we predict that all-oxide heterostructures incorporating ferroelectric constituents, such as KNbO₃=ATiO₃ (A = Sr, Ba, Pb), allow creating a 2DEG switchable between two conduction states by ferroelectric polarization reversal. The effect occurs due to the screening charge at …

Newsletter Of The Wildli Fe Society Wildlife Damage Management Working Group Interactions: Volume 15 Issue 2 Spring 2009

TWS Wildlife Damage Management Working Group Newsletter

The Wildlife Damage Management Meeting Was A Success! Letters From Gary; A Brief Report from the Wildlife Damage Management Conference; Two New Publications Available Dominion Over Wildlife Fifth Eastern Wdm Conference; Conference Announcement Tws Conference Preliminary Program; Workshop Announcement Deer Damage Management Workshop; Call for Papers Special Issue of Human-Wildlife Conflicts To Focus On the Management of North American Geese; Conference Announcement Bird Strike North American Conference; Calls from the Field (Or A House, Or A Farm, Or A…); Conference Announcement 24th Vertebrate Pest Conference; Call for Papers 24th Vertebrate Pest Conference; Recent Wildlife Damage Management Research; The Wildlife Society …

Newsletter Of The Wildlife Society Wildlife Damage Management Working Group Interactions: Volume 15 Issue 1 Winter 2009

TWS Wildlife Damage Management Working Group Newsletter

See You In Saratoga! Letters from Gary; A Brief Report from The WDMWG Meeting and the 2008 TWS Annual Conference; New Product Announcement Backyard Wildlife: Vole Control And Ground Squirrel Management Dvd; Publication Announcement Latest Issue of Human Wildlife Conflicts Is Now Available; Conference Announcement Bird Strike North American Conference; Conference Announcement TWS Conference Preliminary Program; New Publication Available 23rd Vertebrate Pest Conference Proceedings; Calls from the Field (Or A House, Or A Farm, or A…); 2009 Wildlife Damage Management Conference Preliminary Schedule; 2009 Wildlife Damage Management Conference Registration Information; The Wildlife Society Wildlife Damage Management Working Group; Upcoming Meetings, …

Magnetic And Petrologic Characterization Of Synthetic Martian Basalts And Implications For The Surface Magnetization Of Mars, Julie A. Bowles, Julie E. Hammer, Stefanie A. Brachfeld

Geosciences Faculty Articles

A suite of synthetic Martian basalts is generated with the objective of providing fundamental material properties data for use in modeling and interpretation of mission data. We systematically evaluate the effects of major element composition, oxygen fugacity (ƒO₂), and cooling rate on phase chemistry and magnetic mineralogy, grain size, and intensity of remanent magnetization. The range of experimental compositions and ƒO2 are chosen to bracket the range expected in the Martian crust; our results should therefore span the range of possible mineralogies, textures, and magnetic properties in rapidly cooled Mars crustal materials. Two starting compositions are used for …

Winter 2009 Nova Southeastern University Undergraduate Student Catalog, Nova Southeastern University

Undergraduate Programs Course Catalogs

No abstract provided.

A Plotless Density Estimator Based On The Asymptotic Limit Of Ordered Distance Estimation Values, Barry Kronenfeld

Faculty Research and Creative Activity

Estimation of tree density from point-tree distances is an attractive option for quick inventory of new sites, but estimators that are unbiased in clustered and dispersed situations have not been found. Noting that bias of an estimator derived from distances to the kth nearest neighbor from a random point tends to decrease with increasing k, a method is proposed for estimating the limit of an asymptotic function through a set of ordered distance estimators. A standard asymptotic model is derived from the limiting case of a clustered distribution. The proposed estimator is evaluated against 13 types of simulated generating processes, …

An Infrared Imaging Method For High-Throughput Combinatorial Investigation Of Hydrogenation-Dehydrogenation And New Phase Formation Of Thin Films, H. Oguchi, Jason R. Hattrick-Simpers, I. Takeuchi, E. J. Heilweil, L. A. Bendersky

Faculty Publications

We have developed an infrared imaging setup enabling in situ infrared images to be acquired, and expanded on capabilities of an infrared imaging as a high-throughput screening technique, determination of a critical thickness of a Pd capping layer which significantly blocks infrared emission from below, enhancement of sensitivity to hydrogenation and dehydrogenation by normalizing raw infrared intensity of a Mg thin film to an inert reference, rapid and systematic screening of hydrogenation and dehydrogenation properties of a Mg–Ni composition spread covered by a thickness gradient Pd capping layer, and detection of formation of a Mg₂Si phase in a …

Storage, Manipulation, And Visualization Of Lidar Data, Bianca Schoen-Phelan, M. Bertolotto, D. F. Laefer, Sean W. Corish

Conference papers

In recent years, three-dimensional (3D) data has become increasingly available, in part as a result of significant technological progresses in Light Detection and Ranging (LiDAR). LiDAR provides longitude and latitude information delivered in conjunction with a GPS device, and elevation information generated by a pulse or phase laser scanner, which together provide an effective way of acquiring accurate 3D information of a terrestrial or manmade feature. The main advantages of LiDAR over conventional surveying methods lie in the high accuracy of the data and the relatively little time needed to scan large geographical areas. LiDAR scans provide a vast amount …