Physical Sciences and Mathematics Commons^™

Gpu Accelerated Long-Term Simulations Of Beam-Beam Effects In Colliders, B. Terzić, V. Morozov, Y. Roblin, F. Lin, H. Zhang, M. Aturban, D. Ranjan, M. Zubair

Computer Science Faculty Publications

We present an update on the development of the new code for long-term simulation of beam-beam effects in particle colliders. The underlying physical model relies on a matrix-based arbitrary-order particle tracking (including a symplectic option) for beam transport and the generalized Bassetti-Erskine approximation for beam-beam interaction. The computations are accelerated through a parallel implementation on a hybrid GPU/CPU platform. With the new code, previously computationally prohibitive long-term simulations become tractable. The new code will be used to model the proposed Medium-energy Electron-Ion Collider (MEIC) at Jefferson Lab.

Technical Note: Swift - A Fast Semi-Empirical Model For Polar Stratospheric Ozone Loss, M. Rex, S. Kremser, P. Huck, G. Bodeker, I. Wohltmann, M. L. Santee, P. F. Bernath

Chemistry & Biochemistry Faculty Publications

An extremely fast model to estimate the degree of stratospheric ozone depletion during polar winters is described. It is based on a set of coupled differential equations that simulate the seasonal evolution of vortex-averaged hydrogen chloride (HCl), nitric acid (HNO3), chlorine nitrate (ClONO₂), active forms of chlorine (ClO_x = Cl+ClO+2ClOOCl) and ozone (O₃) on isentropic levels within the polar vortices. Terms in these equations account for the chemical and physical processes driving the time rate of change of these species. Eight empirical fit coefficients associated with these terms are derived by iteratively fitting the equations …

Robust Regression Methods For Massively Decayed Intelligence Data, Akiva Joachim Lorenz

Wayne State University Dissertations

Homeland Security, sponsored by governmental initiatives, has become a vibrant academic research field. However, most efforts were placed with the recognition of threats (e.g. theory) and response options. Less effort was placed in the analysis of the collected data through statistical modeling. In a field that collects more than 20 terabyte of information per minute though diverse overt and covert means and indexes it for future research, understanding how different statistical models behave when it comes to massively decayed data is of vital importance.

Using Monte Carlo methods, three regression techniques (ordinary least squares, least-trimmed, and maximum likelihood) were tested …

Fabrication And Measurements Of 500 Mhz Superconducting Double Spoke Cavity, Hyekyoung Park, C. S. Hopper, J. R. Delayen

Physics Faculty Publications

The 500 MHz double spoke cavity has been designed for a high velocity application such as a compact electron accelerator at Center for Accelerator Science at Old Dominion University and is being built at Jefferson Lab. The geometry specific to the double spoke cavity requires a variety of tooling and fixtures. Also a number of joints are expected to make it difficult to maintain the geometric deviation from the design minimal. This paper will report the fabrication technique, resulting tolerance from the design, and comparison between the measurements and simulations.

Cryogenic Test Of A 750 Mhz Superconducting Rf Dipole Crabbing Cavity, A. Castilla, Hyekyoung Park, J. R. Delayen

Physics Faculty Publications

A superconducting rf dipole cavity has been designed to address the challenges of a high repetition rate (750 MHz), high current for both electron/ion species (0.5/3 A per bunch), and large crossing angle (50 mrad) at the interaction points (IPs) crabbing system for the Medium Energy Electron-Ion Collider (MEIC) proposed by Jefferson Lab. The cavity prototype built at Niowave, Inc. has been tested at the Jefferson Lab facilities. In this work we present a detailed analysis of the prototype cavity performance at 4 K and 2 K, corroborating the absence of hard multipacting barriers that could limit the desired transverse …

Analyzing The Effect Of Client Queue Size On Voip And Tcp Traffic Over An Ieee 802.11e Wlan, Sajib Datta, Sajal Das

Computer Science Faculty Research & Creative Works

In this paper we introduce a mathematical model to analyze the performance of Wi-Fi networks carrying voice calls and TCP controlled file downloads. We derive the voice call capacity, the TCP throughput, and the bandwidth utilization using the proposed five-dimensional Markov model. We show that there exists a correlation among the queue size of client nodes and the capacity and throughput of the network. We also demonstrate how bandwidth utilization is affected by variable packet arrival rates. The analytical results match well with the simulation results generated by QualNet simulator. Moreover, we conduct an experimental study of the Enhanced Distributed …

A Simulation-Based Study Of Server Location Selection Rules In Manets Utilising Threshold Cryptography, Alastair Nisbet

Australian Information Security Management Conference

Truly Ad Hoc wireless networks where a spontaneous formation of a network occurs and there is no prior knowledge of nodes to each other present significant security challenges, especially as entirely online configuration of nodes with encryption keys must be performed. Utilising threshold cryptography in this type of MANET can greatly increase the security by requiring servers to collaborate to form a single Certificate Authority (CA). In this type of CA responsibility for certificate services is shared between a threshold of servers, greatly increasing security and making attack against the CA considerably more difficult. Choosing which nodes to take on …

The Halo Occupation Distribution Of X-Ray-Bright Active Galactic Nuclei: A Comparison With Luminous Quasars, Jonathan Richardson, Suchetana Chatterjee, Zheng Zheng, Adam D. Myers, Ryan Hickox

Dartmouth Scholarship

We perform halo occupation distribution (HOD) modeling of the projected two-point correlation function (2PCF) of high-redshift (z~1.2) X-ray-bright active galactic nuclei (AGN) in the XMM-COSMOS field measured by Allevato et al. The HOD parameterization is based on low-luminosity AGN in cosmological simulations. At the median redshift of z~1.2, we derive a median mass of (1.02+0.21/-0.23)x10^{13} Msun/h for halos hosting central AGN and an upper limit of ~10% on the AGN satellite fraction. Our modeling results indicate (at the 2.5-sigma level) that X-ray AGN reside in more massive halos compared to more bolometrically luminous, optically-selected quasars at similar redshift. The modeling …

Modelling The Role Of Cloud Density On The Removal Of Gaseous Pollutants And Particulate Matters From The Atmosphere, Shyam Sundar, Rajan K. Sharma, Ram Naresh

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, a six dimensional nonlinear mathematical model is proposed to study the effect of the density of cloud droplets (formed due to the presence of vapors in the atmosphere) on the removal of pollutants, both gaseous and particulate, from the atmosphere. We assume that there exist six nonlinearly interacting phases in the atmosphere i.e. the vapor phase, the phase of cloud droplets, the phase of raindrops, the phase of gaseous pollutants, the phase of particulate matters and the phase of gaseous pollutants absorbed in raindrops. It is further assumed that the dynamics of the system undergo ecological type …

The Pseudo-Rigid-Body Model For Fast, Accurate, Non-Linear Elasticity, Anthony R. Hall

Theses and Dissertations

We introduce to computer graphics the Pseudo-Rigid-Body Mechanism (PRBM) and the chain algorithm from mechanical engineering, with a unified tutorial from disparate source materials. The PRBM has been used successfully to simplify the simulation of non-linearly elastic beams, using deflections of an analogous spring and rigid-body linkage. It offers computational efficiency as well as an automatic parameterization in terms of physically measurable, intuitive inputs which fit naturally into existing animation work flows for character articulation. The chain algorithm is a technique for simulating the deflection of complicated elastic bodies in terms of straight elastic elements, which has recently been extended …

Next Generation Crystal Viewing Tool, Zach Schaffter, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

The science and engineering community is limited when it comes to crystal viewing software tools. Each tool lacks in a different area such as customization of structures or visual output. Crystal Viewer 2.0 was created to have all of these features in one program. This one tool simulates virtually any crystal structure with any possible material. The vtkvis widget offers users advanced visual options not seen in any other crystal viewing software. In addition, the powerful engine behind Crystal Viewer 2.0, nanoelectronic modeling 5 or (NEMO5), performs intensive atomic calculations depending on user input. A graphical user interface, or GUI, …

Nanohub - Crystal Viewer 2.0, Kevin Margatan, Gerhard Klimeck

The Summer Undergraduate Research Fellowship (SURF) Symposium

nanoHUB is an online compilation of tools for simulations. Equipped with 3-D simulations and a capability to solve very complex calculations, nanoHUB provides its users worldwide with various tools to help them finish their assignments. One of the tools available is called a Crystal Viewer Tool, an advanced crystal visualization tool. This tool allows users to generate various crystal types including their every single detail. Currently, a newer version, called Crystal Viewer 2.0, is being tested prior to its release. However, this tool is lacking some important features and a GUI that is not as user friendly as expected. The …

Developing A Framework For Determining The Contribution Of Transportation Project To Sustainable Development, Karim Ahmed Abdel Warith

Open Access Dissertations

In the past few years, stakeholders in the transportation industry have been concerned with sustainability. However, transportation decision makers have had difficulty incorporating sustainability into transportation infrastructure decisions. This is mainly attributed to the vagueness of the term. Incorporating sustainability into transportation decision making has been a desire put forth by engineers for that past 10 years. However, with no apparent method of defining sustainability, designers and decision makers have not been able to fulfill this desire.

This investigation attempts to define sustainability in a comprehensive and quantitative manner. The research proposes a new methodology that relies on the objective …

Evidence For 20th Century Climate Warming And Wetland Drying In The North American Prairie Pothole Region, Brett A. Werner, W. Carter Johnson, Glenn R. Guntenspergen

Natural Resource Management Faculty Publications

The Prairie Pothole Region (PPR) of North America is a globally important resource that provides abundant and valuable ecosystem goods and services in the form of biodiversity, groundwater recharge, water purification, flood attenuation, and water and forage for agriculture. Numerous studies have found these wetlands, which number in the millions, to be highly sensitive to climate variability. Here, we compare wetland conditions between two 30-year periods (1946–1975; 1976–2005) using a hindcast simulation approach to determine if recent climate warming in the region has already resulted in changes in wetland condition. Simulations using the WETLANDSCAPE model show that 20th century climate …

The Fast And Furious Decay Of The Peculiar Type Ic Supernova 2005ek, M. R. Drout, A. M. Soderberg, P. A. Mazzali, J. T. Parrent

Dartmouth Scholarship

We present extensive multi-wavelength observations of the extremely rapidly declining Type Ic supernova (SN Ic), SN 2005ek. Reaching a peak magnitude of M_R = –17.3 and decaying by ~3 mag in the first 15 days post-maximum, SN 2005ek is among the fastest Type I supernovae observed to date. The spectra of SN 2005ek closely resemble those of normal SN Ic, but with an accelerated evolution. There is evidence for the onset of nebular features at only nine days post-maximum. Spectroscopic modeling reveals an ejecta mass of ~0.3 M _☉ that is dominated by oxygen (~80%), while the pseudo-bolometric light …

Oyster Sustainability Modeling As A Public Resource, Nathan A. Cooper

LSU New Orleans Theses and Dissertations

A simulation algorithm based on biological references points proposed by Powell and Klink (2007) is implemented for predicting the total allowable catch of eastern oysters (Crassostrea virginica) from Louisiana’s coast. The model accepts initial per-square-meter shell mass and oyster size distributions as input. Fishing effort is provided as fractions removed of each resource for each month of the season. The model outputs the expected remaining shell mass and harvests of sack and seed oysters after discrete fishing months. Oyster mortality credits the shell budget, while fishing fractions debit oyster and shell resources. Surviving oysters grow larger along a …

Energy Awareness And Scheduling In Mobile Devices And High End Computing, Sachin S. Pawaskaw

Student Work

In the context of the big picture as energy demands rise due to growing economies and growing populations, there will be greater emphasis on sustainable supply, conservation, and efficient usage of this vital resource. Even at a smaller level, the need for minimizing energy consumption continues to be compelling in embedded, mobile, and server systems such as handheld devices, robots, spaceships, laptops, cluster servers, sensors, etc. This is due to the direct impact of constrained energy sources such as battery size and weight, as well as cooling expenses in cluster-based systems to reduce heat dissipation. Energy management therefore plays a …

The Evolution Of Modular Product Architectures And The Emergence Of Platform Ecosystems, C. Jason Woodard, Eric K. Clemons

Research Collection School Of Computing and Information Systems

While a large body of research has examined the advantages and disadvantages of modularity in product design, studies of modularization have tended to focus on settings in which a product’s architecture is determined by a single designer or designers within a single organization. In this paper, we ask whether modularity can arise in a decentralized setting where high-value designs are rewarded but designers’ ability to coordinate with each other and anticipate the consequences of their actions is limited—in short, whether modularity can evolve. To answer this question, we developed an agent-based model in which boundedly rational firms combine components into …

Characterization Of Optical Communication In A Leader-Follower Unmanned Underwater Vehicle Formation, Firat Eren, Shachak Pe'eri, May-Win Thein

Center for Coastal and Ocean Mapping

As part of the research to development an optical communication design of a leader-follower formation between unmanned underwater vehicles (UUVs), this paper presents light field characterization and design configuration of the hardware required to allow the use of distance detection between UUVs. The study specifically is targeting communication between remotely operated vehicles (ROVs). As an initial step in this study, the light field produced from a light source mounted on the leader UUV was empirically characterized and modeled. Based on the light field measurements, a photo-detector array for the follower UUV was designed. Evaluation of the communication algorithms to monitor …

American Spread Option Models And Valuation, Yu Hu

Theses and Dissertations

Spread options are derivative securities, which are written on the difference between the values of two underlying market variables. They are very important tools to hedge the correlation risk. American style spread options allow the holder to exercise the option at any time up to and including maturity. Although they are widely used to hedge and speculate in financial market, the valuation of the American spread option is very challenging. Because even under the classic assumptions that the underlying assets follow the log-normal distribution, the resulting spread doesn't have a distribution with a simple closed formula. In this dissertation, we …

Simulation And Analysis Of Insider Attacks, Christopher Blake Clark

UNLV Theses, Dissertations, Professional Papers, and Capstones

An insider is an individual (usually an employee, contractor, or business partner) that has been trusted with access to an organization's systems and sensitive data for legitimate purposes. A malicious insider abuses this access in a way that negatively impacts the company, such as exposing, modifying, or defacing software and data.

Many algorithms, strategies, and analyses have been developed with the intent of detecting and/or preventing insider attacks. In an academic setting, these tools and approaches show great promise. To be sure of their effectiveness, however, these analyses need to be tested. While real data is available on insider attacks …

Traffic Modeling In Lagrangian Coordinates Using Smartphone Apps, Sergio Contreras

UNLV Theses, Dissertations, Professional Papers, and Capstones

Traditionally, one of the ways traffic flow has been studied is by using the kinematic wave model. This model is derived in the Eulerian framework by using conservation of the number of vehicles. Recently, the kinematic wave model has been transformed into Lagrangian coordinates. In this framework, the independent variables are unique

vehicles and time. The detailed change in framework, and the properties of the model in the changed framework are reviewed. Numerical results from different traffic cases are explained. Since vehicle trajectory data can be easily collected from smartphones,

a smartphone application is developed for this purpose. This data …

Simulating Inflation, Ryan M. Heathcote

Senior Honors Theses

Inflation is a common problem in modern economics, and it seems to persist, requiring government financial policy intervention on a regular basis in order to properly manage. The mechanics of inflation are difficult to understand, since the best metric modern society has for inflation involves taking samples of prices across the country. A simulation can give deeper insight into more than the mere fact that prices rise over time: a simulation can help to answer the “why” question. The problem with this statement is that developing a simulation is not as simple as writing some code. A simulation is developed …

Stochastic Modeling And Time-To-Event Analysis Of Voip Traffic, Imad Al Ajarmeh

College of Computing and Digital Media Dissertations

Voice over IP (VoIP) systems are gaining increased popularity due to the cost effectiveness, ease of management, and enhanced features and capabilities. Both enterprises and carriers are deploying VoIP systems to replace their TDM-based legacy voice networks. However, the lack of engineering models for VoIP systems has been realized by many researchers, especially for large-scale networks. The purpose of traffic engineering is to minimize call blocking probability and maximize resource utilization. The current traffic engineering models are inherited from the legacy PSTN world, and these models fall short from capturing the characteristics of new traffic patterns. The objective of this …

Semantic Modeling Of Requirements: Leveraging Ontologies In Systems Engineering, Masood S. Mir

Theses and Dissertations

The interdisciplinary nature of Systems Engineering (SE), having stakeholders from diverse domains with orthogonal facets, and need to consider all stages of lifecycle of system during conception, can benefit tremendously by employing Knowledge Engineering (KE) to achieve semantic agreement among all stakeholders for all stages of life cycle. Present practices in SE, such as using Vocabularies, Processes, Standards, and Modeling Languages are oriented towards manual reasoning of system concepts and relations to achieve semantic agreement. Semantic Web (SW) is being developed to provide KE and automated reasoning to the unstructured information, in huge amounts, present on the World Wide Web, …

Modeling And Analysis Of Information Product Maps, Christopher Harris Heien

Theses and Dissertations

Information Product Maps are visual diagrams used to represent the inputs, processing, and outputs of data within an Information Manufacturing System. A data unit, drawn as an edge, symbolizes a grouping of raw data as it travels through this system. Processes, drawn as vertices, transform each data unit input into various forms prior to delivery to consumers. These visual representations act as documentation for all processes, and data unit transformations, leading to the final construction and delivery of an Information Product. The science of Information Quality strives to measure the fitness for use of these products, expressed by consumer satisfaction. …

Optimized Simulation Of Granular Materials, Seth R. Holladay

Theses and Dissertations

Visual effects for film and animation often require simulated granular materials, such as sand, wheat, or dirt, to meet a director's needs. Simulating granular materials can be time consuming, in both computation and labor, as these particulate materials have complex behavior and an enormous amount of small-scale detail. Furthermore, a single cubic meter of granular material, where each grain is a cubic millimeter, would contain a billion granules, and simulating all such interacting granules would take an impractical amount of time for productions. This calls for a simplified model for granular materials that retains high surface detail and granular behavior …

Preliminary Simulation Study On Classification Of Large Molecules By Newly Designed Cascade Type Differential Mobility Analyzer (Ctdma), Chenxi Zhu

Student Theses and Dissertations

Differential mobility analyzer (DMA), coupled with other instrumentation analyzers, such as mass spectrometry (MS), can classify size, masses and shapes by their different gas-phase electrophoretic mobility. In order to obtain the high resolution in classifying large particles (50 kD ~ 1 MD), our laboratory designed several versions of cylindrical cascade type differential mobility analyzers (CTDMA). Because CTDMAs consist of two cylindrical particle classifiers in one housing, target particles are guided through "gaps" and "stairs", a unique feature to this new particle classification device. Two modes of operation--outward cross flow mode and no-cross flow mode--both reduce the flow rate in the …

Electric Field Standing Wave Effects In Ft-Ir Transflection Spectra Of Biological Tissue Sections: Simulated Models Of Experimental Variability, Tomasz P. Wrobel, Barbara Wajnchold, Hugh Byrne, Malgorzata Baranska

Articles

The so-called electric field standing wave effect (EFSW) has recently been demonstrated to significantly distort FT-IR spectra acquired in a transflection mode, both experimentally and in simulated models, bringing into question the appropriateness of the technique for sample characterization, particularly in the field of spectroscopy of biological materials. The predicted effects are most notable in the regime where the sample thickness is comparable to the source wavelength. In this work, the model is extended to sample thicknesses more representative of biological tissue sections and to include typical experimental factors which are demonstrated to reduce the predicted effects. These include integration …

Simulation Of A Large Electric Distribution System Having Intensive Harmonics In The Industrial Zone Of Konya, Hasan Eroğlu, Musa Aydin

Turkish Journal of Electrical Engineering and Computer Sciences

In this study, measurements were taken at different points of a sample distribution system in order to analyze the levels of harmonics that appear as a day-to-day increasing problem in electrical distribution systems. According to the measurement values, the dominant harmonics have been determined and an electrical model of the system has been prepared using the SimPowerSystems toolbox from MATLAB and Simulink. The accuracy of the electrical model has been verified by the measurement and simulation values. In addition, the transformer connection types' and impedances' simulations have been presented to understand and solve the harmonic problems in electrical distribution systems. …