Testing The Adequacy Of A Semi-Markov Process, 2015 Air Force Institute of Technology
Testing The Adequacy Of A Semi-Markov Process, Richard S. Seymour
Theses and Dissertations
Due to the versatility of its structure, the semi-Markov process is a powerful modeling tool used to describe complex systems. Though similar in structure to continuous time Markov chains, semi-Markov processes allow for any transition time distribution which enables these processes to t a wider range of problems than the continuous time Markov chain. While semi-Markov processes have been applied in fields as varied as biostatistics and finance, there does not exist a theoretically-based, systematic method to determine if a semi-Markov process accurately fits the underlying data used to create the model. In fields such as regression and analysis of …
Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, 2015 The University of Western Ontario
Secondary Electrohydrodynamic Flow Generated By Corona And Dielectric Barrier Discharges, Mohammadreza Ghazanchaei
Electronic Thesis and Dissertation Repository
One of the main goals of applied electrostatics engineering is to discover new perspectives in a wide range of research areas. Controlling the fluid media through electrostatic forces has brought new important scientific and industrial applications. Electric field induced flows, or electrohydrodynamics (EHD), have shown promise in the field of fluid dynamics. Although numerous EHD applications have been explored and extensively studied so far, most of the works are either experimental studies, which are not capable to explain the in depth physics of the phenomena, or detailed analytical studies, which are not time effective. The focus of this study is …
Art, Math, And Physics; All About For, 2015 Fresno Pacific University
Art, Math, And Physics; All About For, Chris Brownell, Steve Pauls
The STEAM Journal
Anish Kapoor’s public sculpture “Cloud Gate” and Frame of Reference.
Construction Of Nonlinear Expression For Recursive Number Sequences, 2015 Illinois Wesleyan University
Construction Of Nonlinear Expression For Recursive Number Sequences, Tian-Xiao He
Scholarship
A type of nonlinear expressions of Lucas sequences are established inspired by Hsu [9]. Using the relationships between the Lucas sequence and other linear recurring sequences satisfying the same recurrence relation of order 2, we may transfer the identities of Lucas sequences to the latter.
Per-Contact Infectivity Of Hcv Associated With Injection Exposures In A Prospective Cohort Of Young Injection Drug Users In San Francisco, Ca (Ufo Study), 2015 University of New Mexico
Per-Contact Infectivity Of Hcv Associated With Injection Exposures In A Prospective Cohort Of Young Injection Drug Users In San Francisco, Ca (Ufo Study), Yuridia Leyva
Mathematics & Statistics ETDs
Sharing needles and ancillary injection drug equipment places injection drug users (IDU) at risk for Hepatitis C Virus (HCV), a highly infectious blood-borne virus. A limited number of studies have analyzed the per-contact infectivity of HCV associated with the use of previously-used needles, but per-contact infectivity of ancillary injecting equipment has not been previously investigated. Our goal is to estimate the per-contact infectivity of HCV associated with (1) injecting with another person's previously-used needle, classified as receptive needle sharing (RNS), and (2) using another person's previously-used ancillary injecting equipment, such as cookers to melt drugs and cottons to strain impurities …
Sex Allocation And The Emergence Of Helping In Cooperatively Breeding Species., 2015 Western University
Sex Allocation And The Emergence Of Helping In Cooperatively Breeding Species., Josh D Dunn, Teodora Vujicic, Geoff Wild
Applied Mathematics Publications
In cooperative breeding systems individuals invest in the reproductive success of others. In this paper, we study the emergence of cooperative breeding systems in which reproductively active breeders receive investment from reproductively non-active helpers. Our goal is to understand how the division of an investment between male and female components of breeder fitness (i.e. the helper sex-allocation strategy) influences the emergence of cooperative breeding itself. Using mathematical models, we arrive at expressions for the inclusive-fitness advantage of helpful behaviour that generalize previous work. These expressions assume an ecologically stable environment, and that breeders make evolutionarily stable sex-allocation decisions. We find …
Transients Of Platoons With Asymmetric And Different Laplacians, 2015 Czech Technical University, Prague
Transients Of Platoons With Asymmetric And Different Laplacians, Ivo Herman, Dan Martinec, J. J. P. Veerman
Mathematics and Statistics Faculty Publications and Presentations
We consider an asymmetric control of platoons of identical vehicles with nearest-neighbor interaction. Recent results show that if the vehicle uses different asymmetries for position and velocity errors, the platoon has a short transient and low overshoots. In this paper we investigate the properties of vehicles with friction. To achieve consensus, an integral part is added to the controller, making the vehicle a third-order system. We show that the parameters can be chosen so that the platoon behaves as a wave equation with different wave velocities. Simulations suggest that our system has a better performance than other nearest-neighbor scenarios. Moreover, …
Wall Mechanical Properties And Hemodynamics Of Unruptured Intracranial Aneurysms, 2015 George Mason University
Wall Mechanical Properties And Hemodynamics Of Unruptured Intracranial Aneurysms, J. R. Cebral, X. Duan, Bong Jae Chung, C. Putman, Khaled Aziz, A. M. Robertson
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
BACKGROUND AND PURPOSE: Aneurysm progression and rupture is thought to be governed by progressive degradation and weakening of the wall in response to abnormal hemodynamics. Our goal was to investigate the relationship between the intra-aneurysmal hemodynamic conditions and wall mechanical properties in human aneurysms. MATERIALS AND METHODS: A total of 8 unruptured aneurysms were analyzed. Computational fluid dynamics models were constructed from preoperative 3D rotational angiography images. The aneurysms were clipped, and the domes were resected and mechanically tested to failure with a uniaxial testing system under multiphoton microscopy. Linear regression analysis was performed to explore possible correlations between hemodynamic …
Construction Of Nonlinear Expression For Recursive Number Sequences, 2015 Illinois Wesleyan University
Construction Of Nonlinear Expression For Recursive Number Sequences, Tian-Xiao He
Tian-Xiao He
Collaboration And Health Care Diagnostics: An Agent Based Model Simulation, 2015 Purdue University
Collaboration And Health Care Diagnostics: An Agent Based Model Simulation, Sebastian Linde, George K. Thiruvathukal
George K. Thiruvathukal
This paper presents a simple ABM simulation that seeks to provide insight into the public health benefits that derive from greater collaboration among health care professionals. In particular, the paper compares the efficiency, delivery and timeliness of health care diagnostics under two contrasting paradigms–one in which collaboration is encouraged, and an- other where it is not. The preliminary results of this study suggest that while the effect of cooperation on aggregate public health depends on the patient search algorithm employed, its effect on overall efficiency and timeliness of health care diagnostics and treatment is significant and pos- itive. Since the …
Coarsening In High Order, Discrete, Ill-Posed Diffusion Equations, 2015 University of Dayton
Coarsening In High Order, Discrete, Ill-Posed Diffusion Equations, Catherine Kublik
Catherine Kublik
We study the discrete version of a family of ill-posed, nonlinear diffusion equations of order 2n. The fourth order (n=2) version of these equations constitutes our main motivation, as it appears prominently in image processing and computer vision literature. It was proposed by You and Kaveh as a model for denoising images while maintaining sharp object boundaries (edges). The second order equation (n=1) corresponds to another famous model from image processing, namely Perona and Malik's anisotropic diffusion, and was studied in earlier papers. The equations studied in this paper are high order analogues of the Perona-Malik equation, and like the …
Algorithms For Area Preserving Flows, 2015 University of Dayton
Algorithms For Area Preserving Flows, Catherine Kublik, Selim Esedoglu, Jeffrey A. Fessler
Catherine Kublik
We propose efficient and accurate algorithms for computing certain area preserving geometric motions of curves in the plane, such as area preserving motion by curvature. These schemes are based on a new class of diffusion generated motion algorithms using signed distance functions. In particular, they alternate two very simple and fast operations, namely convolution with the Gaussian kernel and construction of the distance function, to generate the desired geometric flow in an unconditionally stable manner. We present applications of these area preserving flows to large scale simulations of coarsening.
An Implicit Interface Boundary Integral Method For Poisson’S Equation On Arbitrary Domains, 2015 University of Dayton
An Implicit Interface Boundary Integral Method For Poisson’S Equation On Arbitrary Domains, Catherine Kublik, Nicolay M. Tanushev, Richard Tsai
Catherine Kublik
We propose a simple formulation for constructing boundary integral methods to solve Poisson’s equation on domains with smooth boundaries defined through their signed distance function. Our formulation is based on averaging a family of parameterizations of an integral equation defined on the boundary of the domain, where the integrations are carried out in the level set framework using an appropriate Jacobian. By the coarea formula, the algorithm operates in the Euclidean space and does not require any explicit parameterization of the boundaries. We present numerical results in two and three dimensions.
Lyapunov Functionals That Lead To Exponential Stability And Instability In Finite Delay Volterra Difference Equations, 2015 University of Dayton
Lyapunov Functionals That Lead To Exponential Stability And Instability In Finite Delay Volterra Difference Equations, Catherine Kublik, Youssef Raffoul
Catherine Kublik
We use Lyapunov functionals to obtain sufficient conditions that guarantee exponential stability of the zero solution of the finite delay Volterra difference equation. Also, by displaying a slightly different Lyapunov functional, we obtain conditions that guarantee the instability of the zero solution. The highlight of the paper is the relaxing of the condition |a(t)| < 1. Moreover, we provide examples in which we show that our theorems provide an improvement of some recent results.
Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, 2015 The University of Western Ontario
Tropical Cyclone Wind Hazard Assessment For Southeast Part Of Coastal Region Of China, Sihan Li
Electronic Thesis and Dissertation Repository
Tropical cyclone (TC) or typhoon wind hazard and risk are significant for China. The return period value of the maximum typhoon wind speed is used to characterize the typhoon wind hazard and assign wind load in building design code. Since the historical surface observations of typhoon wind speed are often scarce and of short period, the typhoon wind hazard assessment is often carried out using the wind field model and TC track model. For a few major cities in the coastal region of mainland China, simple or approximated wind field models and a circular subregion method (CSM) have been used …
Topographic Signatures Of Geodynamics, 2015 Earth and Climate Sciences
Topographic Signatures Of Geodynamics, Samuel G. Roy
Electronic Theses and Dissertations
The surface of the Earth retains an imperfect memory of the diverse geodynamic, climatic, and surface transport processes that cooperatively drive the evolution of Earth. In this thesis I explore the potential of using topographic analysis and landscape evolution models to unlock past and/or present evidence for geodynamic activity. I explore the potential isolated effects of geodynamics on landscape evolution, particularly focusing on two byproducts of tectonic strain: rock displacement and damage. Field evidence supports a strong correlation between rock damage and erodibility, and a numerical sensitivity analysis supports the hypothesis that an order of magnitude weakening in rock, well …
Numerical Solutions Of Generalized Burgers' Equations For Some Incompressible Non-Newtonian Fluids, 2015 The University of New Orleans
Numerical Solutions Of Generalized Burgers' Equations For Some Incompressible Non-Newtonian Fluids, Yupeng Shu
University of New Orleans Theses and Dissertations
The author presents some generalized Burgers' equations for incompressible and isothermal flow of viscous non-Newtonian fluids based on the Cross model, the Carreau model, and the Power-Law model and some simple assumptions on the flows. The author numerically solves the traveling wave equations for the Cross model, the Carreau model, the Power-Law model by using industrial data. The author proves existence and uniqueness of solutions to the traveling wave equations of each of the three models. The author also provides numerical estimates of the shock thickness as well as maximum strain $\varepsilon_{11}$ for each of the fluids.
A Framework For Inferring Unobserved Multistrain Epidemic Subpopulations Using Synchronization Dynamics, 2015 Montclair State University
A Framework For Inferring Unobserved Multistrain Epidemic Subpopulations Using Synchronization Dynamics, Eric Forgoston, Leah B. Shaw, Ira B. Schwartz
Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works
A new method is proposed to infer unobserved epidemic subpopulations by exploiting the synchronization properties of multistrain epidemic models. A model for dengue fever is driven by simulated data from secondary infective populations. Primary infective populations in the driven system synchronize to the correct values from the driver system. Most hospital cases of dengue are secondary infections, so this method provides a way to deduce unobserved primary infection levels. We derive center manifold equations that relate the driven system to the driver system and thus motivate the use of synchronization to predict unobserved primary infectives. Synchronization stability between primary and …
Simulating And Animating The Spatial Dynamics Of Interacting Species Living On A Torus, 2015 CUNY New York City College of Technology
Simulating And Animating The Spatial Dynamics Of Interacting Species Living On A Torus, Boyan Kostadinov
Publications and Research
The goal of this talk is to present a student research project in computational population biology, which aims at creating a computer simulation and animation of the spatial dynamics of interactions between two kinds of species living on a torus-shaped universe. The habitat for spatial interactions is modeled by a 2D lattice with periodic boundary conditions, which wrap the rectangular grid into a torus. The spatial interactions between the species have two components: 1. Population dynamics modeled by the classical Nicholson-Bailey two-parameter family of models for coupled interactions between species, extended to incorporate space and 2. Two-parameter migration dynamics, modeled …
Chaotic Behavior In Monetary Systems: Comparison Among Different Types Of Taylor Rule, 2015 Auckland University of Technology
Chaotic Behavior In Monetary Systems: Comparison Among Different Types Of Taylor Rule, Reza Moosavi Mohseni Dr., Wenjun Zhang Dr., Jiling Cao Prof.
Reza Moosavi Mohseni
The aim of the present study is to detect the chaotic behavior in the monetary economic relevant dynamical system. The study employs three different forms of Taylor rules: current, forward and backward looking. The result suggests the existence of the chaotic behavior in all three systems. In addition, the results strongly represent that using expectations in policy rule especially rational expectation hypothesis can increase the complexity of the system and leads to more chaotic behavior.