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2006

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Articles 4291 - 4320 of 5872

Full-Text Articles in Physical Sciences and Mathematics

A New Cryptographic Scheme For Securing Dynamic Conferences In Data Networks, Sarang Deshpande, Ajay Todimala, Ravi K Balachandran, Byrav Ramamurthy, Xukai Zou, N. V. Vinodchandran Jan 2006

A New Cryptographic Scheme For Securing Dynamic Conferences In Data Networks, Sarang Deshpande, Ajay Todimala, Ravi K Balachandran, Byrav Ramamurthy, Xukai Zou, N. V. Vinodchandran

CSE Conference and Workshop Papers

Dynamic conferencing refers to a scenario wherein any subset of users in a universe of users form a conference for sharing confidential information among themselves. The key distribution (KD) problem in dynamic conferencing is to compute a shared secret key for such a dynamically formed conference. In literature, the KD schemes for dynamic conferencing either are computationally unscalable or require communication among users, which is undesirable. The extended symmetric polynomial based dynamic conferencing scheme (ESPDCS) is one such KD scheme which has a high computational complexity that is universe size dependent. In this paper we present an enhancement to the …


Router And Firewall Redundancy With Openbsd And Carp, Garhan Attebury, Byrav Ramamurthy Jan 2006

Router And Firewall Redundancy With Openbsd And Carp, Garhan Attebury, Byrav Ramamurthy

CSE Conference and Workshop Papers

As more reliance is placed on computing and networking systems, the need for redundancy increases. The Common Address Redundancy Protocol (CARP) protocol and OpenBSD’s pfsync utility provide a means by which to implement redundant routers and firewalls. This paper details how CARP and pfsync work together to provide this redundancy and explores the performance one can expect from the open source solutions. Two experiments were run: one showing the relationship between firewall state creation and state synchronization traffic and the other showing how TCP sessions are transparently maintained in the event of a router failure. Discussion of these simulations along …


Autonomous Clustering-Based Heterogeneous Waveband Switching In Wdm Networks, Mengke Li, Byrav Ramamurthy Jan 2006

Autonomous Clustering-Based Heterogeneous Waveband Switching In Wdm Networks, Mengke Li, Byrav Ramamurthy

CSE Conference and Workshop Papers

Employing waveband switching (WBS) in WDM networks can reduce the network operational cost and the call blocking probability. However, upgrading the existing optical switching architecture requires time and money. It is expected that a heterogeneous waveband switching (HeteroWBS) architecture would be desirable, where some nodes can support WBS functions and some cannot. We study the performance of HeteroWBS networks in terms of call blocking probability and cost savings under dynamic traffic requests. We propose an autonomous clustering-based HeteroWBS (AS-HeteroWBS) architecture to clusters the network into multiple autonomous systems (ASs). An AS may contain some specific nodes that provide WBS functions …


A Generic Autonomous Clustering-Based Heterogeneous Waveband Switching Architecture In Wdm Networks, Mengke Li, Byrav Ramamurthy Jan 2006

A Generic Autonomous Clustering-Based Heterogeneous Waveband Switching Architecture In Wdm Networks, Mengke Li, Byrav Ramamurthy

CSE Conference and Workshop Papers

Heterogeneous waveband switching (HeteroWBS) in WDM networks reduces the network operational costs. We propose an autonomous clustering-based HeteroWBS architecture to support the design of efficient HeteroWBS algorithms under dynamic traffic requests in such a network.


Dynamic Lightpath Scheduling In Next-Generation Wdm Optical Networks, Lu Shen, Ajay Todimala, Byrav Ramamurthy, Xi Yang Jan 2006

Dynamic Lightpath Scheduling In Next-Generation Wdm Optical Networks, Lu Shen, Ajay Todimala, Byrav Ramamurthy, Xi Yang

CSE Conference and Workshop Papers

Lightpath scheduling is an important capability in next-generation wavelength-division multiplexing (WDM) optical networks to reserve resources in advance for a specified time period while provisioning end-to-end lightpaths. In this study, we propose an approach to support dynamic lightpath scheduling in such networks. To minimize blocking probability in a network that accommodates dynamic scheduled lightpath demands (DSLDs), resource allocation should be optimized in a dynamic manner. However, for the network users who desire deterministic services, resources must be reserved in advance and guaranteed for future use. These two objectives may be mutually incompatible. Therefore, we propose a two-phase dynamic lightpath scheduling …


Approximation Algorithms For Survivable Multicommodity Flow Problems With Applications To Network Design, Ajay Todimala, Byrav Ramamurthy Jan 2006

Approximation Algorithms For Survivable Multicommodity Flow Problems With Applications To Network Design, Ajay Todimala, Byrav Ramamurthy

CSE Conference and Workshop Papers

Multicommodity flow (MF) problems have a wide variety of applications in areas such as VLSI circuit design, network design, etc., and are therefore very well studied. The fractional MF problems are polynomial time solvable while integer versions are NP-complete. However, exact algorithms to solve the fractional MF problems have high computational complexity. Therefore approximation algorithms to solve the fractional MF problems have been explored in the literature to reduce their computational complexity. Using these approximation algorithms and the randomized rounding technique, polynomial time approximation algorithms have been explored in the literature.

In the design of high-speed networks, such as …


An Efficient Scheduling Scheme For On-Demand Lightpath Reservations In Reconfigurable Wdm Optical Networks, Xi Yang, Lu Shen, Ajay Todimala, Byrav Ramamurthy, Tom Lehman Jan 2006

An Efficient Scheduling Scheme For On-Demand Lightpath Reservations In Reconfigurable Wdm Optical Networks, Xi Yang, Lu Shen, Ajay Todimala, Byrav Ramamurthy, Tom Lehman

CSE Conference and Workshop Papers

We propose an efficient scheduling scheme that optimizes advance-reserved lightpath services in reconfigurable WDM networks. A re-optimization approach is devised to reallocate network resources for dynamic service demands while keeping determined schedule unchanged.


Active Learning To Maximize Area Under The Roc Curve, Matt Culver, Deng Kun, Stephen Scott Jan 2006

Active Learning To Maximize Area Under The Roc Curve, Matt Culver, Deng Kun, Stephen Scott

CSE Conference and Workshop Papers

In active learning, a machine learning algorithmis given an unlabeled set of examples U, and is allowed to request labels for a relatively small subset of U to use for training. The goal is then to judiciously choose which examples in U to have labeled in order to optimize some performance criterion, e.g. classification accuracy. We study how active learning affects AUC. We examine two existing algorithms from the literature and present our own active learning algorithms designed to maximize the AUC of the hypothesis. One of our algorithms was consistently the top performer, and Closest Sampling from the literature …


Cross-Layer Analysis Of Error Control In Wireless Sensor Networks, Mehmet C. Vuran, Ian F. Akyildiz Jan 2006

Cross-Layer Analysis Of Error Control In Wireless Sensor Networks, Mehmet C. Vuran, Ian F. Akyildiz

CSE Conference and Workshop Papers

Severe energy constraints and hence the low power communication requirements amplify the significance of the energy efficient and preferably cross-layer error control mechanisms in Wireless Sensor Networks (WSN). In this paper, a crosslayer methodology for the analysis of error control schemes in WSNs is presented such that the effects of multi-hop routing and the broadcast nature of the wireless channel are investigated. More specifically, the cross-layer effects of routing, medium access and physical layers are considered. This analysis enables a comprehensive comparison of forward error correction (FEC) and automatic repeat request (ARQ) in WSNs.
FEC schemes improve the error resiliency …


A Constraint-Based Approach To Solving Minesweeper, Ken Bayer, Josh Snyder, Berthe Y. Choueiry Jan 2006

A Constraint-Based Approach To Solving Minesweeper, Ken Bayer, Josh Snyder, Berthe Y. Choueiry

CSE Conference and Workshop Papers

·Motivate the students for the study of Constraint Processing (CP). Minesweeper is perfect to this end because it allows us to illustrate the use of CP algorithms in a familiar context and show how they operate.

·Understand and demystify humans’ fascination with puzzles.

·Discourage graduate students from losing too much time playing the game by making a program that plays the game for them.


Origin And Tectonic Significance Of The Metamorphic Sole And Isolated Dykes Of The Divriği Ophiolite (Sivas, Turkey): Evidence For Slab Break-Off Prior To Ophiolite Emplacement, Osman Parlak, Hüseyi̇n Yilmaz, Durmuş Boztuğ Jan 2006

Origin And Tectonic Significance Of The Metamorphic Sole And Isolated Dykes Of The Divriği Ophiolite (Sivas, Turkey): Evidence For Slab Break-Off Prior To Ophiolite Emplacement, Osman Parlak, Hüseyi̇n Yilmaz, Durmuş Boztuğ

Turkish Journal of Earth Sciences

The Late Cretaceous Divriği ophiolite of east-central Anatolia comprises, from bottom to top, an ophiolitic mélange, metamorphic sole and remnants of oceanic lithosphere. The ophiolitic mélange has been thrust onto the Lower Carboniferous-Campanian Munzur Limestone (Tauride platform), and is in turn tectonically overlain by the metamorphic sole. The metamorphic-sole rocks are represented by amphibolite, plagioclase amphibolite, plagioclase-amphibole schist, plagioclase-epidote-amphibole schist and calc-schist. The oceanic-lithosphere remnant exhibits a complete section, excluding volcanic rocks, comprising mantle tectonites, ultramafic to mafic cumulates, isotropic gabbros and sheeted dykes. Isolated dykes intrude the metamorphic sole and mantle tectonites at different structural levels. The metamorphic-sole rocks …


Complexity Trends In The Evolutionary History Of Dasycladalean Algae, Michael Stearns Jan 2006

Complexity Trends In The Evolutionary History Of Dasycladalean Algae, Michael Stearns

Senior Honors Theses and Projects

Dasycladalean algae are a group of marine algae that have an excellent fossil record extending back more than 500 million years. In our study, we investigated morphological complexity over the evolutionary history of this group. To determine complexity for each of more than 400 species, we assigned numerical values for six morphological features; the sum for each species forms a quantitative expression of complexity. We found that although maximum complexity increased over time, forms with minimum complexity persisted during most of the evolutionary history of the group.


Inequality For Ricci Curvature Of Slant Submanifolds In Cosymplectic Space Forms, Dae Won Yoon Jan 2006

Inequality For Ricci Curvature Of Slant Submanifolds In Cosymplectic Space Forms, Dae Won Yoon

Turkish Journal of Mathematics

In this article, we establish inequalities between the Ricci curvature and the squared mean curvature, and also between the k-Ricci curvature and the scalar curvature for a slant, semi-slant and bi-slant submanifold in a cosymplectic space form of constant \varphi-sectional curvature with arbitrary codimension.


Remarks About Some Weierstrass Type Results, Mihai Turinici Jan 2006

Remarks About Some Weierstrass Type Results, Mihai Turinici

Turkish Journal of Mathematics

The Weierstrass type results of Gajek and Zagrodny [7] are not in general retainable in the precise context. Our first aim in this exposition is to show that a completion of the imposed conditions may be offered so that these results be true. As a second aim, alternate proofs of the statements in question are performed, via ordering principles comparable with the one in Brezis and Browder [3].


A Critical Appraisal Of The Opportunities Currently Available For A More Energy Conscious Approach To Residential Building In Ireland, John Mcdonagh, Louis Gunnigan Jan 2006

A Critical Appraisal Of The Opportunities Currently Available For A More Energy Conscious Approach To Residential Building In Ireland, John Mcdonagh, Louis Gunnigan

Conference papers

This paper focuses on the particular advantages which off-site housing construction has over the more traditional methods of building especially where the efficient use and conservation of energy is concerned. It will explain why modern innovative methods of house construction not only have a clear advantage environmentally (big reductions in CO2 emissions) but also deliver substantial benefits to the end user or householder especially in the form of lower energy bills.

The ecological argument for off-site systems is a very powerful one but on its own is still unlikely to be the prime driver for widespread implementation. That growth is …


Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi Jan 2006

Integrating Micro-Scale Separations To Matrix Assisted Laser Desorption And Ioniation Time Of Flight Mass Spectrometry (Maldi-Tof-Ms) For Protein Analysis, Harrison K. Musyimi

LSU Doctoral Dissertations

This dissertation describes the integration of micro-scale separations to matrix assisted laser desorption and ionization time-of-flight mass spectrometry (MALDI TOF MS) for protein analysis. MALDI MS provides unsurpassed accurate mass measurements of intact bio-molecules, for example peptides and proteins, which in turn generate high molecular specificity enabling the identity, function and structure of these molecules to be characterized. However, in order to realize the full potential of MS in proteomic studies, integrated sample processing on automated and high throughput platforms is required to address the complexity, diversity and the dynamic range of proteomic analysis. The work described here contributes towards …


Monodomain Dynamics For Rigid Rod And Platelet Suspensions In Strongly Coupled Coplanar Linear Flow And Magnetic Fields. Ii. Kinetic Theory, M. Gregory Forest, Sarthok Sircar, Qi Wang, Ruhai Zhou Jan 2006

Monodomain Dynamics For Rigid Rod And Platelet Suspensions In Strongly Coupled Coplanar Linear Flow And Magnetic Fields. Ii. Kinetic Theory, M. Gregory Forest, Sarthok Sircar, Qi Wang, Ruhai Zhou

Mathematics & Statistics Faculty Publications

We establish reciprocity relations of the Doi-Hess kinetic theory for rigid rod macromolecular suspensions governed by the strong coupling among an excluded volume potential, linear flow, and a magnetic field. The relation provides a reduction of the flow and field driven Smoluchowski equation: from five parameters for coplanar linear flows and magnetic field, to two field parameters. The reduced model distinguishes flows with a rotational component, which map to simple shear (with rate parameter) subject to a transverse magnetic field (with strength parameter), and irrotational flows, for which the reduced model consists of a triaxial extensional flow (with two extensional …


Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang Jan 2006

Porous Inorganic-Organic Materials Based On Beta-Diketone Ligands, Yixun Zhang

LSU Doctoral Dissertations

Synthesis and characterization of porous inorganic-organic materials have been studied mainly on two linear β-diketone multifunctional ligands: pyridine based pyacH and isocyanide based HacphNC. As a known ligand, the preparation of pyacH has been improved with higher yield. When pyacH reacts with Fe and Al metal salts, trigonal metal β-diketonate building blocks M(pyac)3 are produced. When pyacH reacts with zinc acetate, both trans and cis Zn(pyac)2 are produced, both isomers were isolated and characterized by single-crystal X-ray crystallography. Solutions of the trigonal building block Fe(pyac)3 generate various crystal structures on reaction with AgNO3 in CH3CN. When the concentration of AgNO3 …


Ontology-Based Methodology For Error Detection In Software Design, Allyson M. Hoss Jan 2006

Ontology-Based Methodology For Error Detection In Software Design, Allyson M. Hoss

LSU Doctoral Dissertations

Improving the quality of a software design with the goal of producing a high quality software product continues to grow in importance due to the costs that result from poorly designed software. It is commonly accepted that multiple design views are required in order to clearly specify the required functionality of software. There is universal agreement as to the importance of identifying inconsistencies early in the software design process, but the challenge is how to reconcile the representations of the diverse views to ensure consistency. To address the problem of inconsistencies that occur across multiple design views, this research introduces …


Belowground Biomass Of Spartina Alterniflora: Seasonal Variability And Response To Nutrients, Faith Armand Darby Jan 2006

Belowground Biomass Of Spartina Alterniflora: Seasonal Variability And Response To Nutrients, Faith Armand Darby

LSU Doctoral Dissertations

Spartina alterniflora is a salt marsh macrophyte found from Canada to the Gulf of Mexico which often provides the dominant plant cover. Although S. alterniflora is well known for its high aboveground productivity, fifty to ninety percent of the total plant production occurs belowground. No previous studies address the seasonal variation of belowground biomass or the response of above-and belowground biomass to nutrients at the southern limits of its U. S. range. The objectives of this study were to: 1) document the seasonal variability of its above- and belowground biomass and test for responses to various combinations of N, P, …


Development Of Analytical Techniques For The Analysis Of Submicron Particles And Protein Aggregates, Yohannes H. Rezenom Jan 2006

Development Of Analytical Techniques For The Analysis Of Submicron Particles And Protein Aggregates, Yohannes H. Rezenom

LSU Doctoral Dissertations

The goal of the research presented in this dissertation is to develop analytical techniques for the analysis of heterogeneous mixtures of submicron particles and protein aggregates. In Chapter 2, a simple and reproducible technique for constructing perfectly aligned gaps in fused-silica capillaries has been developed for postcolumn reagent addition with capillary electrophoresis (CE) to take advantage of laser-induced fluorescence (LIF) detection. This technique uses laser ablation with a Nd:YAG laser to create gaps of 14.0 ¡Ó 2.2 ƒÝm. These structures have been used for reagent addition for postcolumn derivatization with LIF detection and have been tested for the separation of …


Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters Jan 2006

Influence Of Surface Chemistry On The Aggregation Of Beta Amyloid Peptide, Mariah Joan Wooldridge Mcmasters

LSU Doctoral Dissertations

Alzheimer's disease is a progressive neurological ailment affecting 4.5 million aging Americans. The disease is characterized by the presence in the brain of self-assembled fibrils consisting of beta amyloid protein (Aβ). Soluble Aβ protein is present in normal human cerebrospinal fluid, but it is unclear what makes the protein aggregate into insoluble plaques. There is evidence that the Aβ fibril assembly is affected by interactions with biological surfaces, such as neuronal membranes. Here, surfaces consisting of self-assembled alkanethiol monolayers with different end groups were used to test the effect of surface chemistry on the structure and morphology of aggregates formed …


Kinetic Correlation In Photo-Double-Ionization Processes: The He-Isoelectronic Sequence, Sebastian Otranto, C. R. Garibotti Jan 2006

Kinetic Correlation In Photo-Double-Ionization Processes: The He-Isoelectronic Sequence, Sebastian Otranto, C. R. Garibotti

Physics Faculty Research & Creative Works

Analytical models proposed to represent the two-electron continuum are revisited. Main results obtained with these models are summarized. Recent studies of the photo-double-ionization (PDI) of the He-isoelectronic sequence by means of the recently introduced SC3 model are shown and compared with the results predicted by classical and semi-classical Wannier approaches. By fitting the triply differential cross sections (TDCSs) with the usual dipolar Gaussian form we find that the width has a power dependence on excess energy with exponent 0.25 in the near threshold region and departs from this law with increasing energy


Self-Optimization Of Optical Confinement In An Ultraviolet Photonic Crystal Slab Laser, Alexey Yamilov, X. Wu, X. Liu, Hui Cao, Robert P. H. Chang Jan 2006

Self-Optimization Of Optical Confinement In An Ultraviolet Photonic Crystal Slab Laser, Alexey Yamilov, X. Wu, X. Liu, Hui Cao, Robert P. H. Chang

Physics Faculty Research & Creative Works

We studied numerically and experimentally the effects of structural disorder on the performance of ultraviolet photonic crystal slab lasers. Optical gain selectively amplifies the high-quality modes of the passive system. For these modes, the in-plane and out-of-plane leakage rates may be automatically balanced in the presence of disorder. The spontaneous optimization of in-plane and out-of-plane confinement of light in a photonic crystal slab may lead to a reduction of the lasing threshold.


Theoretical Treatment Of Electron-Impact Ionization Of Molecules, Junfang Gao, Jerry Peacher, Don H. Madison Jan 2006

Theoretical Treatment Of Electron-Impact Ionization Of Molecules, Junfang Gao, Jerry Peacher, Don H. Madison

Physics Faculty Research & Creative Works

There is currently no reliable theory for calculating the fully differential cross section (FDCS) for low energy electron-impact ionization of molecules. All of the existing experimental FDCS data represent averages over all molecular orientations and this can be an important theoretical complication for calculations that are computer intensive. We have found that using an averaged molecular orbital is an accurate approximation for ionization of ground states. In this paper, we will describe the approximation, discuss its expected range of validity and show some FDCS results using the approximation for ionization of H2 and N2


Adiabatic-Nonadiabatic Transition In The Diffusive Hamiltonian Dynamics Of A Classical Holstein Polaron, Alex A. Silvius, Paul Ernest Parris, Stephan De Bièvre Jan 2006

Adiabatic-Nonadiabatic Transition In The Diffusive Hamiltonian Dynamics Of A Classical Holstein Polaron, Alex A. Silvius, Paul Ernest Parris, Stephan De Bièvre

Physics Faculty Research & Creative Works

We study the Hamiltonian dynamics of a free particle injected onto a chain containing a periodic array of harmonic oscillators in thermal equilibrium. The particle interacts locally with each oscillator, with an interaction that is linear in the oscillator coordinate and independent of the particle's position when it is within a finite interaction range. At long times the particle exhibits diffusive motion, with an ensemble averaged mean-squared displacement that is linear in time. The diffusion constant at high temperatures follows a power law D~T 5/2 for all parameter values studied. At low temperatures particle transport changes to a hopping process …


Unexpected Higher-Order Effects In Charged Particle Impact Ionization At High Energies, M. Foster, Jerry Peacher, Michael Schulz, Don H. Madison, Zhangjin Chen, H. R. J. Walters Jan 2006

Unexpected Higher-Order Effects In Charged Particle Impact Ionization At High Energies, M. Foster, Jerry Peacher, Michael Schulz, Don H. Madison, Zhangjin Chen, H. R. J. Walters

Physics Faculty Research & Creative Works

Most of the experimental and theoretical studies of electron-impact ionization of atoms, referred to as (e, 2e), have concentrated on the scattering plane. The assumption has been that all the important physical effects will be observable in the scattering plane. However, very recently it has been shown that, for C6+-helium ionization, experiment and theory are in nice agreement in the scattering plane and in very bad agreement out of the scattering plane. This lack of agreement between experiment and theory has been explained in terms of higher-order scattering effects between the projectile and target ion. We have examined electron-impact ionization …


Ip's Problem Child: Shifting The Paradigms For Software Protection, Jacqueline D. Lipton Jan 2006

Ip's Problem Child: Shifting The Paradigms For Software Protection, Jacqueline D. Lipton

Articles

Computer software is somewhat of a problem child for intellectual property law. Courts and legislatures have struggled to encourage innovations in software development while, at the same time, attempting to avoid undesirable digital information monopolies. Neither the patent nor the copyright system has provided a particularly satisfactory paradigm for software protection. Although patents have received greater attention than copyrights in the software context (consider, for example, the recent BlackBerry case), copyright law arguably creates more insidious undercurrents in today's marketplace. This is partly because we have not yet appreciated the potential impact of recent developments in programming methodology and digital …


Computer Models For Legal Prediction, Kevin D. Ashley, Stephanie Bruninghaus Jan 2006

Computer Models For Legal Prediction, Kevin D. Ashley, Stephanie Bruninghaus

Articles

Computerized algorithms for predicting the outcomes of legal problems can extract and present information from particular databases of cases to guide the legal analysis of new problems. They can have practical value despite the limitations that make reliance on predictions risky for other real-world purposes such as estimating settlement values. An algorithm's ability to generate reasonable legal arguments also is important. In this article, computerized prediction algorithms are compared not only in terms of accuracy, but also in terms of their ability to explain predictions and to integrate predictions and arguments. Our approach, the Issue-Based Prediction algorithm, is a program …


The Antecedents Of M-Commerce Adoption, Morris Kalliny, Michael S. Minor Jan 2006

The Antecedents Of M-Commerce Adoption, Morris Kalliny, Michael S. Minor

Business and Information Technology Faculty Research & Creative Works

The growth of Internet shopping has been attributed to rapid advances in technology and other influences such as convenience. We empirically investigate the relationship between demographics, ease of use, convenience, usefulness and enjoyment and intention to use m-commerce and attitude toward m-commerce. Two studies were conducted where a student and a non student sample was used. Data analysis revealed age, gender and educational level of customers do not play a role in influencing intention to use m-commerce. However, convenience, ease of use, usefulness and enjoyment all play a role in the customer's intention to use m-commerce.