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Full-Text Articles in Physical Sciences and Mathematics

Simulation Study For Wireless Sensor Networks And Load Sharing Routing Protocol To Increase Network Life And Connectivity, Ankur Suri Jan 2005

Simulation Study For Wireless Sensor Networks And Load Sharing Routing Protocol To Increase Network Life And Connectivity, Ankur Suri

LSU Master's Theses

LSU SensorSimulator is a framework for simulating wireless sensor networks. It is a customizable and extendible simulator, which allows testing and analyzing software for wireless sensor networks. The users can subclass the framework classes and customize the behavior of various network layers. This subclassing gives a way to the developers an opportunity to analyze and investigate, phenomenological, networking, robustness and scaling issues, to explore arbitrary algorithms for distributed sensors, independent of hardware constraint. The results are compared against the simulation results for ns-2 for routing protocols Directed Diffusion and GEAR. Through the comparison of results for scalability, performance and memory …


Sensorsimulator: Simulation Framework For Sensor Networks, Cariappa D. Mallanda Jan 2005

Sensorsimulator: Simulation Framework For Sensor Networks, Cariappa D. Mallanda

LSU Master's Theses

Wireless sensor networks have the potential to become significant subsystems of engineering applications. Before relegating important and safety-critical tasks to such subsystems, it is necessary to understand the dynamic behavior of these subsystems in simulation environments. There is an urgent need to develop a simulation platform that is useful to explore both the networking issues and the distributed computing aspects of wireless sensor networks. Current approaches to simulating wireless sensor networks largely focus on the networking issues. These approaches use well-known network simulation tools that are often difficult to extend to explore distributed computing issues. Discrete-event simulation is a trusted …


Pseudo-Random Number Generation In R For Commonly Used Multivariate Distributions, Hakan Demirtas Nov 2004

Pseudo-Random Number Generation In R For Commonly Used Multivariate Distributions, Hakan Demirtas

Journal of Modern Applied Statistical Methods

An increasing number of practitioners and applied statisticians have started using the R programming system in recent years for their computing and data analysis needs. As far as pseudo-random number generation is concerned, the built-in generator in R does not contain multivariate distributions. In this article, R routines for widely used multivariate distributions are presented.


Studies Of Disk Arrays Tolerating Two Disk Failures And A Proposal For A Heterogeneous Disk Array, Chunqi Han May 2004

Studies Of Disk Arrays Tolerating Two Disk Failures And A Proposal For A Heterogeneous Disk Array, Chunqi Han

Dissertations

There has been an explosion in the amount of generated data in the past decade. Online access to these data is made possible by large disk arrays, especially in the RAID (Redundant Array of Independent Disks) paradigm. According to the RAID level a disk array can tolerate one or more disk failures, so that the storage subsystem can continue operating with disk failure(s). RAID 5 is a single disk failure tolerant array which dedicates the capacity of one disk to parity information. The content on the failed disk can be reconstructed on demand and written onto a spare disk. However, …


Synthetic Image Generation Of Shallow Water Using An Iterative Layered Radiative Transfer Model With Realistic Water Surface Waves, Charles R. Bostater Jr., Lisa Huddleston, Luce Bassetti Feb 2004

Synthetic Image Generation Of Shallow Water Using An Iterative Layered Radiative Transfer Model With Realistic Water Surface Waves, Charles R. Bostater Jr., Lisa Huddleston, Luce Bassetti

Ocean Engineering and Marine Sciences Faculty Publications

Modeled hyperspectral reflectance signatures just above the water surface are obtained from an analytical-based, iterative radiative transport model applicable to shallow water types. Light transport within the water body is simulated using a fast, accurate radiative transfer model that calculates the light distribution in any layered media. A realistic water surface is synthesized using empirically-based spectral models of the ocean surface to generate water surface waves. Images are displayed as 24 bit RGB images of the water surface using selected channels from a synthetic hyperspectral image cube. The selected channels are centered at 490, 530 and 676 nm. Hyperspectral image …


Data Assimilation Of Avhrr And Modis Data For Land Base Initialization And Boundary Conditions In The Utc-M Atmospheric Boundary Layer Sea-Breeze Model Of Space Coast Florida, Charles R. Bostater Jr., Jerome A. King, Lisa H. Huddleston, Luce Bassetti Feb 2004

Data Assimilation Of Avhrr And Modis Data For Land Base Initialization And Boundary Conditions In The Utc-M Atmospheric Boundary Layer Sea-Breeze Model Of Space Coast Florida, Charles R. Bostater Jr., Jerome A. King, Lisa H. Huddleston, Luce Bassetti

Ocean Engineering and Marine Sciences Faculty Publications

The purpose of this paper is to present results of simulations of the Florida Tech UTC-M sea-breeze model22 with the addition of a simplified atmospheric downwelling radiation subroutine1,4 combined and a thermal inertia subroutine17,19,20 into the atmospheric planetary boundary layer model, in order to calculate time dependant heat flux boundary conditions at the air-land boundary that are derived from satellite data from AVHRR and MODIS sensors. The improved UTC-M planetary boundary layer model with this thermal sub-model subroutine is used to demonstrate the use of thermal inertia to help estimate heat fluxes at the land-air interface which in turn influences …


Use Of Next Generation Weather Radar Data And Basin Disaggregation To Improve Continuous Hydrograph Simulations, Ziya Zhang, Victor Koren, Michael Smith, Seann Reed, David Wang Jan 2004

Use Of Next Generation Weather Radar Data And Basin Disaggregation To Improve Continuous Hydrograph Simulations, Ziya Zhang, Victor Koren, Michael Smith, Seann Reed, David Wang

United States Department of Commerce: Staff Publications

Currently, the river forecasting system deployed in each of 13 River Forecast Centers of the National Weather Service primarily uses lumped parameter models to generate hydrologic simulations. With the deployment of the weather surveillance radar 1988 Doppler radars, more and more precipitation data with high spatial and temporal resolution have become available for hydrologic modeling. Hydrologists inside and outside the National Weather Service are now investigating how to effectively use these data to enhance river-forecasting capabilities. In this paper, six years of continuously simulated hydrographs from an eight-subbasin model are compared to those from a single-basin (or lumped) model, both …


A Novel Approach To Information Security Risk Analysis, Bilge Karabacak, Ibrahim Sogukpinar Jan 2004

A Novel Approach To Information Security Risk Analysis, Bilge Karabacak, Ibrahim Sogukpinar

All Faculty and Staff Scholarship

A number of risk analysis methods became obsolete because of the profound changes in information technologies. Revolutionary changes in information technologies have converted many risk analysis methods into inconsistent, long lasting and expensive instruments. Therefore, risk analysis methods should be adaptively modified or redesigned according to the changes in information technologies, so that they meet the information security requirements of the organizations. By taking these requirements into consideration, a survey based approach is proposed for analyzing the risks of information technologies. This new method is named as Risk Analysis Method for Information Security (RAMIS). A case study is conducted to …


Diffusional Interactions At Dual Disk Microelectrodes: Comparison Of Experiment With Three-Dimensional Random Walk Simulations, John E. Baur, Perry N. Motsegood Jan 2004

Diffusional Interactions At Dual Disk Microelectrodes: Comparison Of Experiment With Three-Dimensional Random Walk Simulations, John E. Baur, Perry N. Motsegood

Faculty Publications – Chemistry

Three dimensional random walk simulations were used to model the diffusional interactions between coplanar dual disk microelectrodes. Working curves for the dependence of shielding factor, collection efficiency, and amplification factor on the size of the gap between the electrodes were developed. The simulations showed that when the gap size was ≥22 radii, the electrodes could be considered as independent and diffusionally isolated. Empirical equations for determining the gap size from simple shielding and generator-collector experiments were established. The simulation was used to model the collector electrode response for square waves of various frequencies applied to the generator electrode. Simulation results …


Quantization With Knowledge Base Applied To Geometrical Nesting Problem, Grzegorz Chmaj, Leszek Koszalka Jan 2004

Quantization With Knowledge Base Applied To Geometrical Nesting Problem, Grzegorz Chmaj, Leszek Koszalka

Electrical & Computer Engineering Faculty Research

Nesting algorithms deal with placing two-dimensional shapes on the given canvas. In this paper a binary way of solving the nesting problem is proposed. Geometric shapes are quantized into binary form, which is used to operate on them. After finishing nesting they are converted back into original geometrical form. Investigations showed, that there is a big influence of quantization accuracy for the nesting effect. However, greater accuracy results with longer time of computation. The proposed knowledge base system is able to strongly reduce the computational time.


Resonant Photoemission In F-Electron Systems: Pu And Gd, James G. Tobin, Brandon W. Chung, Roland K. Schulze, Jeff Russell Terry, John Douglas Farr, David K. Shuh, K. Heinzelman, Eli Rotenberg, George Daniel Waddill, Gerrit V. Van Der Laan Oct 2003

Resonant Photoemission In F-Electron Systems: Pu And Gd, James G. Tobin, Brandon W. Chung, Roland K. Schulze, Jeff Russell Terry, John Douglas Farr, David K. Shuh, K. Heinzelman, Eli Rotenberg, George Daniel Waddill, Gerrit V. Van Der Laan

Physics Faculty Research & Creative Works

Resonant photoemission in the Pu 5f and Pu 6p states is compared to that in the Gd 4f and Gd 5p states. Spectral simulations, based upon an atomic model with angular momentum coupling, are compared to the Gd and Pu results. Additional spectroscopic measurements of Pu, including core level photoemission and x-ray absorption, are also presented.


You Think You’Ve Got Trivials?, Shlomo S. Sawilowsky May 2003

You Think You’Ve Got Trivials?, Shlomo S. Sawilowsky

Theoretical and Behavioral Foundations of Education Faculty Publications

Effect sizes are important for power analysis and meta-analysis. This has led to a debate on reporting effect sizes for studies that are not statistically significant. Contrary and supportive evidence has been offered on the basis of Monte Carlo methods. In this article, clarifications are given regarding what should be simulated to determine the possible effects of piecemeal publishing trivial effect sizes.


Not All Effects Are Created Equal: A Rejoinder To Sawilowsky, J. Kyle Roberts, Robin K. Henson May 2003

Not All Effects Are Created Equal: A Rejoinder To Sawilowsky, J. Kyle Roberts, Robin K. Henson

Journal of Modern Applied Statistical Methods

In the continuing debate over the use and utility of effect sizes, more discussion often helps to both clarify and syncretize methodological views. Here, further defense is given of Roberts & Henson (2002) in terms of measuring bias in Cohen’s d, and a rejoinder to Sawilowsky (2003) is presented.


Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls May 2003

Computer Simulation And Homogenization In Heating Design Optimization, Daniel K. Balls

All Graduate Plan B and other Reports, Spring 1920 to Spring 2023

The ability to ensure uniformity of temperature within a given finite physical region is an essential element in the success of many scientific processes, especially those that involve extreme fluctuation in temperature. Such a process is performed in an instrument called the LightTyper developed by Idaho Technology, Inc. of Salt Lake City Utah. This paper details the development and results of a scheme intended to obtain a heating design that ensures a high degree of temperature uniformity within the Idaho Technology instrument. Due to the experiments performed during this project, we were able to answer many questions that concerned finding …


You Think You’Ve Got Trivials?, Shlomo S. Sawilowsky May 2003

You Think You’Ve Got Trivials?, Shlomo S. Sawilowsky

Journal of Modern Applied Statistical Methods

Effect sizes are important for power analysis and meta-analysis. This has led to a debate on reporting effect sizes for studies that are not statistically significant. Contrary and supportive evidence has been offered on the basis of Monte Carlo methods. In this article, clarifications are given regarding what should be simulated to determine the possible effects of piecemeal publishing trivial effect sizes.


Simulation Of Groundwater Flow In Cache Valley, Utah And Idaho, Barry Myers May 2003

Simulation Of Groundwater Flow In Cache Valley, Utah And Idaho, Barry Myers

All Graduate Theses and Dissertations, Spring 1920 to Summer 2023

A groundwater model of Cache Valley was created using MODFLOW. Steady-state calibration of the model demonstrated that recharge to the lower confined aquifer may occur along the margin of the valley that borders the Wellsville Mountains and the Bear River Range. Steady-state calibration also showed that discharge from the unconfined aquifer may occur along the eastern and western margins of the valley in both the Utah and the Idaho portions of the valley.

Two simulations were run with increased pumping of 3 5 cubic feet per second (1 cubic meter per second) from the principal aquifer. The first simulation was …


Hyperspectral Remote Sensing Protocol Development For Submerged Aquatic Vegetation In Shallow Waters, Charles R. Bostater Jr., T. Ghir, L. Bassetti, Carlton Hall, E. Reyier, R. Lowers, K. Holloway-Adkins, Robert Virnstein Feb 2003

Hyperspectral Remote Sensing Protocol Development For Submerged Aquatic Vegetation In Shallow Waters, Charles R. Bostater Jr., T. Ghir, L. Bassetti, Carlton Hall, E. Reyier, R. Lowers, K. Holloway-Adkins, Robert Virnstein

Ocean Engineering and Marine Sciences Faculty Publications

Submerged aquatic vegetation (SAV) is an important indicator of freshwater and marine water quality in almost all shallow water aquatic environments. Throughout the world the diversity of submerged aquatic vegetation appears to be in decline, although sufficient historical data, of sufficient quantitative quality is lacking. Hyperspectral remote sensing technology, available from low altitude aircraft sensors, may provide a basis to improve upon existing photographic regional assessments and monitoring concerned with the aerial extent and coverage of SAV. In addition, modern low altitude remote sensing may also help in the development of environmental satellite requirements for future satellite payloads. This paper …


Initial Electron Beam Polarization Measurement In E-\Gamma Collisions, Gökhan Ünel Jan 2003

Initial Electron Beam Polarization Measurement In E-\Gamma Collisions, Gökhan Ünel

Turkish Journal of Physics

The future high energy e e colliders, together with the complementary \gamma \gamma option, will offer possibilities for both discovery and precision physics. The uncertainty on the initial beam polarizations contributes to the systematic errors in each case. Therefore, it is crucial to obtain the precise beam polarizations by independent measurements. The e \gamma \rightarrow \nu W process in the e \gamma mode can be used to experimentally determine the polarization of the initial e beam. This note addresses the feasibility of making such a measurement with a relative statistical error of one percent. Generator and detector level MC tools …


Security Management Education Online, Peter J. Hosie, Clifton L. Smith, Joseph Luca Jan 2003

Security Management Education Online, Peter J. Hosie, Clifton L. Smith, Joseph Luca

Research outputs pre 2011

This paper describes the philosophy and pedagogy informing the design and development of Security Science online units. The Physical Security unit is used to illustrate the development of the online learning strategies and interactive activities. Learning materials developed for this course have unique attributes as they were specifically designed to provide simulations and interactivity in the learning process. Field scenarios have been developed for the activities to make the learning experiences as realistic as possible. Simulations and graphics provide these experiences, together with security site images for actual security barriers, systems and technologies. Features of units in the course include …


Development And Implementation Of Fine Structure Aerosol Spectrum Coagulation Kernels And Deposition Mechanisms Using Advanced Nodal Method In The Caerot Code, Hyeongkae Park Jan 2003

Development And Implementation Of Fine Structure Aerosol Spectrum Coagulation Kernels And Deposition Mechanisms Using Advanced Nodal Method In The Caerot Code, Hyeongkae Park

LSU Master's Theses

Aerosol transport in confined spaces was studied via numerical simulation using the dynamic aerosol equation, which is Boltzmann?s transport equation at the hydrodynamic limit. Until recent years, there existed no comprehensive computational tool to predict the spatial distribution and time evolution of aerosol size spectrum. A previously developed code, INDASOL3D, solves the dynamic aerosol equation by using a homogenized control-volume based finite difference method applying the group sectional method on the coagulation dynamics. However, quantitative correctness has not been satisfactory. In this thesis, two new codes (SAEROSA, and CAEROT) were developed. SAEROSA computes the time evolution of the size spectrum …


A Simulation Study Of The Impact Of Forecast Recovery For Control Charts Applied To Arma Processes, John N. Dyer, B. Michael Adams, Michael D. Conerly Nov 2002

A Simulation Study Of The Impact Of Forecast Recovery For Control Charts Applied To Arma Processes, John N. Dyer, B. Michael Adams, Michael D. Conerly

Journal of Modern Applied Statistical Methods

Forecast-based schemes are often used to monitor autocorrelated processes, but the resulting forecast recovery has a significant effect on the performance of control charts. This article describes forecast recovery for autocorrelated processes, and the resulting simulation study is used to explain the performance of control charts applied to forecast errors.


Jmasm3: A Method For Simulating Systems Of Correlated Binary Data, Todd C. Headrick May 2002

Jmasm3: A Method For Simulating Systems Of Correlated Binary Data, Todd C. Headrick

Journal of Modern Applied Statistical Methods

An efficient algorithm is derived for generating systems of correlated binary data. The procedure allows for the specification of all pairwise correlations within each system. Intercorrelations between systems can be specified qualitatively. The procedure requires the simultaneous solution of a system of equations for obtaining the threshold probabilities to generate each system of binary data. A numerical example is provided to demonstrate that the procedure generates correlated binary variables that yield correlations in close agreement with the specified population correlations.


Perspectives On The Evolution Of Simulation, Richard E. Nance, Robert G. Sargent Jan 2002

Perspectives On The Evolution Of Simulation, Richard E. Nance, Robert G. Sargent

Electrical Engineering and Computer Science - All Scholarship

Simulation is introduced in terms of its different forms and uses, but the focus on discrete event modeling for systems analysis is dominant as it has been during the evolution of the technique within operations research and the management sciences. This evolutionary trace of over almost fifty years notes the importance of bidirectional influences with computer science, probability and statistics, and mathematics. No area within the scope of operations research and the management sciences has been affected more by advances in computing technology than simulation. This assertion is affirmed in the review of progress in those technical areas that collectively …


Electronic Structure Of Superconducting Mgb₂ And Related Binary And Ternary Borides, Nadezhda I. Medvedeva, Alexander L. Ivanovskii, Julia E. Medvedeva, Arthur J. Freeman Jun 2001

Electronic Structure Of Superconducting Mgb₂ And Related Binary And Ternary Borides, Nadezhda I. Medvedeva, Alexander L. Ivanovskii, Julia E. Medvedeva, Arthur J. Freeman

Physics Faculty Research & Creative Works

First-principles full potential linear muffin-tin orbital-generalized gradient approximation electronic structure calculations of the new medium-Tc superconductor (MTSC) MgB2 and related diborides indicate that superconductivity in these compounds is related to the existence of Px,y-band holes at the γ point. Based on these calculations, we explain the absence of medium-Tc superconductivity for BeB2, AlB2, ScB2, and YB2. The simulation of a number of MgB2-based ternary systems using a supercell approach demonstrates that (i) the electron doping of MgB2 (i.e., MgB2-yXy with X=Be, …


Quantitative Analysis Of Domain Testing Effectiveness., Narendra Koneru May 2001

Quantitative Analysis Of Domain Testing Effectiveness., Narendra Koneru

Electronic Theses and Dissertations

The criticality of the applications modeled by the real-time software places stringent requirements on software quality before deploying into real use. Though automated test tools can be used to run a large number of tests efficiently, the functionality of any test tool is not complege without providing a means for analyzing the test results to determine potential problem sub-domains and sub-domains that need to be covered, and estimating the reliability of the modeled system.

This thesis outlines a solution strategy and implementation of that strategy for deriving quantitative metrics from domain testing of real-time control software tested via simulation. The …


Time Step Truncation Error In Direct Simulation Monte Carlo, Alejandro Garcia, W. Wagner Jan 2000

Time Step Truncation Error In Direct Simulation Monte Carlo, Alejandro Garcia, W. Wagner

Faculty Publications

No abstract provided.


An Iron-Based Ecosystem Model Of The Central Equatorial Pacific, Carrie L. Leonard, Charles R. Mcclain, Ragu Murtugudde, Eileen E. Hofmann, Lawrence W. Harding Jr. Jan 1999

An Iron-Based Ecosystem Model Of The Central Equatorial Pacific, Carrie L. Leonard, Charles R. Mcclain, Ragu Murtugudde, Eileen E. Hofmann, Lawrence W. Harding Jr.

CCPO Publications

The central and eastern equatorial Pacific region is characterized by lower than expected phytoplankton biomass and primary production given the relatively high ambient nitrate concentrations. These unusual conditions have spawned several field programs and laboratory experiments to determine why this high nitrate-low chlorophyll pattern persists in this region. To synthesize the results from these field programs, as well as providing additional evidence in support of the iron hypothesis, we developed a one-dimensional, nine-component ecosystem model of 0 degrees N 140 degrees W. The model components include two phytoplankton size fractions, two zooplankton size fractions, two detrital size fractions, dissolved iron, …


Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults Jul 1998

Comparison Of Observed And Simulated Grow-Finish Swine Performance Under Summer Conditions, Larry W. Turner, Thomas C. Bridges, Richard D. Coffey, Richard S. Gates, Gary R. Parker, Tami M. Brown-Brandl, Douglas G. Overhults

Biosystems and Agricultural Engineering Faculty Publications

As a part of a National Pork Producers Council educational program, our research and extension team at the University of Kentucky was linked with an independent commercial swine producer to test the NCPIG model against observed commercial on-farm data. This experience provided improved information for model development as well as increased producer insight into the data input needs and potential benefits of modeling. Detailed production information comparisons between the NCPIG model and producer data are presented for summer time conditions to assess the validity of the NCPIG model for simulation of grow-finish swine performance. Results demonstrated that the NCPIG model …


Optimum Preventive Maintenance Policies For The Amraam Missile, Scott J. Ruflin Feb 1998

Optimum Preventive Maintenance Policies For The Amraam Missile, Scott J. Ruflin

Theses and Dissertations

The overall objective of this research effort was to formulate a preventive maintenance strategy for AMRAAM missiles subject to extended captive carry flight time. A preventive maintenance policy is only applicable if the item in question is aging, or deteriorating with time. Therefore, a supporting objective of this research is to characterize the aging process of the missile system through a non-parametric analysis of its Mean Residual Life (MRL) function. Three non-parametric, censored-data MRL function estimation techniques discussed in the literature are examined via a numerical example. All three estimation techniques provide MRL functions that exhibit greatly exaggerated decreasing trends …


Monte Carlo Simulation In Environmental Risk Assessment--Science, Policy And Legal Issues, Susan R. Poulter Jan 1998

Monte Carlo Simulation In Environmental Risk Assessment--Science, Policy And Legal Issues, Susan R. Poulter

RISK: Health, Safety & Environment (1990-2002)

Dr. Poulter notes that agencies should anticipate judicial requirements for justification of Monte Carlo simulations and, meanwhile, should consider, e.g., whether their use will make risk assessment policy choices more opaque or apparent.