Applied Mathematics Commons^™

Conformal Mapping Improvement Of The Boundary Element Method Solution For Underground Water Flow In A Domain With A Very Singular Boundary, Megan Romero

UNLV Theses, Dissertations, Professional Papers, and Capstones

Numerical solutions using a Boundary Element Method (BEM) for a confined flow in a very singular finite domain are developed. Typically, in scientific journal publications, authors avoid domains with many and more malignant singularities due to the extremely big and difficult to estimate errors in the numerical calculations. Using exact Conformal Mapping solutions for simplified domains with the same singularity as in the original domain, this problem can be solved numerically with improvements introduced by Conformal Mapping solutions. Firstly, to experiment with improving the BEM solution by Conformal Mapping, a domain inside a rectangle is considered. The exact solution inside …

Developing Optimization Techniques For Logistical Tendering Using Reverse Combinatorial Auctions, Jennifer Kiser

Electronic Theses and Dissertations

In business-to-business logistical sourcing events, companies regularly use a bidding process known as tendering in the procurement of transportation services from third-party providers. Usually in the form of an auction involving a single buyer and one or more sellers, the buyer must make decisions regarding with which suppliers to partner and how to distribute the transportation lanes and volume among its suppliers; this is equivalent to solving the optimization problem commonly referred to as the Winner Determination Problem. In order to take into account the complexities inherent to the procurement problem, such as considering a supplier’s network, economies of scope, …

Interpolating Between Multiplicities And F-Thresholds, William D. Taylor

Graduate Theses and Dissertations

We define a family of functions, called s-multiplicity for each s>0, that interpolates between Hilbert-Samuel multiplicity and Hilbert-Kunz multiplicity by comparing powers of ideals to the Frobenius powers of ideals. The function is continuous in s, and its value is equal to Hilbert-Samuel multiplicity for small values of s and is equal to Hilbert-Kunz multiplicity for large values of s. We prove that it has an associativity formula generalizing the associativity formulas for Hilbert-Samuel and Hilbert-Kunz multiplicity. We also define a family of closures, called s-closures, such that if two ideals have the same s-closure then they have the …

Fast Adjustable Npn Classification Using Generalized Symmetries, Xuegong Zhou, Lingli Wang, Peiyi Zhao, Alan Mishchenko

Mathematics, Physics, and Computer Science Faculty Articles and Research

NPN classification of Boolean functions is a powerful technique used in many logic synthesis and technology mapping tools in FPGA design flows. Computing the canonical form of a function is the most common approach of Boolean function classification. In this paper, a novel algorithm for computing NPN canonical form is proposed. By exploiting symmetries under different phase assignments and higher-order symmetries of Boolean functions, the search space of NPN canonical form computation is pruned and the runtime is dramatically reduced. The algorithm can be adjusted to be a slow exact algorithm or a fast heuristic algorithm with lower quality. For …

Clustering Mixed Data: An Extension Of The Gower Coefficient With Weighted L2 Distance, Augustine Oppong

Electronic Theses and Dissertations

Sorting out data into partitions is increasing becoming complex as the constituents of data is growing outward everyday. Mixed data comprises continuous, categorical, directional functional and other types of variables. Clustering mixed data is based on special dissimilarities of the variables. Some data types may influence the clustering solution. Assigning appropriate weight to the functional data may improve the performance of the clustering algorithm. In this paper we use the extension of the Gower coefficient with judciously chosen weight for the L2 to cluster mixed data.The benefits of weighting are demonstrated both in in applications to the Buoy data set …

Full Field Computing For Elastic Pulse Dispersion In Inhomogeneous Bars, A. Berezovski, R. Kolman, M. Berezovski, D. Gabriel, V. Adamek

Publications

In the paper, the finite element method and the finite volume method are used in parallel for the simulation of a pulse propagation in periodically layered composites beyond the validity of homogenization methods. The direct numerical integration of a pulse propagation demonstrates dispersion effects and dynamic stress redistribution in physical space on example of a one-dimensional layered bar. Results of numerical simulations are compared with analytical solution constructed specifically for the considered problem. Analytical solution as well as numerical computations show the strong influence of the composition of constituents on the dispersion of a pulse in a heterogeneous bar and …

On Some Ergodic Impulse Control Problems With Constraint, J. L. Menaldi, Maurice Robin

Mathematics Faculty Research Publications

This paper studies the impulse control of a general Markov process under the average (or ergodic) cost when the impulse instants are restricted to be the arrival times of an exogenous process, and this restriction is referred to as a constraint. A detailed setting is described, a characterization of the optimal cost is obtained as a solution of an HJB equation, and an optimal impulse control is identified.

Calculus Of The Impossible: Review Of The Improbability Principle (2014) By David Hand And The Logic Of Miracles (2018) By Lásló Mérő, Samuel L. Tunstall

Numeracy

David J. Hand. 2014. The Improbability Principle: Why Coincidences, Miracles, and Rare Events Happen Every Day (New York, NY: Scientific American/Farrar, Straus and Giroux) 288 pp. ISBN: 978-0374175344.

Lásló Mérő. 2018. The Logic of Miracles: Making Sense of Rare, Really Rare, and Impossibly Rare Events (New Haven, CT: Yale University Press) 288 pp. ISBN: 978-0300224153.

David Hand and Lásló Mérő both grapple with the occurrence of seemingly impossible events in these two popular science books. In this comparative review, I describe the two books, and explain why I prefer Hand's treatment of the impossible.

Curve Tracking Control Under State Constraints And Uncertainties, Robert Kelly Sizemore

LSU Doctoral Dissertations

We study a class of steering control problems for free-moving particles tracking a curve in the plane and also in a three-dimensional environment, which are central problems in robotics. In the two-dimensional case, we provide adaptive controllers for curve tracking under unknown curvatures and control uncertainty. The system dynamics include a nonlinear dependence on the curvature, and are coupled with an estimator for the unknown curvature to form the augmented error dynamics. This nonlinear dependence puts our curvature identification objective outside the scope of existing adaptive tracking and parameter identification results that were limited to cases where the unknown parameters …

Robust Commuter Movement Inference From Connected Mobile Devices, Achintya Kundu, Pengqian Yu, Laura Wynter, Shiau Hong Lim

Research Collection School Of Computing and Information Systems

We present a class of methods for robust, personalized federated learning, called Fed+, that unifies many federated learning algorithms. The principal advantage of this class of methods is to better accommodate the real-world characteristics found in federated training, such as the lack of IID data across parties, the need for robustness to outliers or stragglers, and the requirement to perform well on party-specific datasets. We achieve this through a problem formulation that allows the central server to employ robust ways of aggregating the local models while keeping the structure of local computation intact. Without making any statistical assumption on the …

Extended Poisson Models For Count Data With Inflated Frequencies, Monika Arora

Mathematics & Statistics Theses & Dissertations

Count data often exhibits inflated counts for zero. There are numerous papers in the literature that show how to fit Poisson regression models that account for the zero inflation. However, in many situations the frequencies of zero and of some other value k tends to be higher than the Poisson model can fit appropriately. Recently, Sheth-Chandra (2011), Lin and Tsai (2012) introduced a mixture model to account for the inflated frequencies of zero and k. In this dissertation, we study basic properties of this mixture model and parameter estimation for grouped and ungrouped data. Using stochastic representation we show …

Lower Order Perturbations Of Critical Fractional Laplacian Equations, Khalid Fanoukh Al Oweidi

Theses and Dissertations

We give sufficient conditions for the existence of nontrivial solutions to a class of critical nonlocal problems of the Brezis-Nirenberg type. Our result extends some results in the literature for the local case to the nonlocal setting. It also complements the known results for the nonlocal case.

Non-Local Methods In Fracture Dynamics, Eyad Said

LSU Doctoral Dissertations

We first introduce a regularized model for free fracture propagation based on non-local potentials. We work within the small deformation setting and the model is developed within a state based peridynamic formulation. At each instant of the evolution we identify the softening zone where strains lie above the strength of the material. We show that deformation discontinuities associated with flaws larger than the length scale of non-locality $\delta$ can become unstable and grow. An explicit inequality is found that shows that the volume of the softening zone goes to zero linearly with the length scale of non-local interaction. This scaling …

Masked Instability: Within-Sector Financial Risk In The Presence Of Wealth Inequality, Youngna Choi

Department of Applied Mathematics and Statistics Faculty Scholarship and Creative Works

We investigate masked financial instability caused by wealth inequality. When an economic sector is decomposed into two subsectors that possess a severe wealth inequality, the sector in entirety can look financially stable while the two subsectors possess extreme financially instabilities of opposite nature, one from excessive equity, the other from lack thereof. The unstable subsector can result in further financial distress and even trigger a financial crisis. The market instability indicator, an early warning system derived from dynamical systems applied to agent-based models, is used to analyze the subsectoral financial instabilities. Detailed mathematical analysis is provided to explain what financial …

Building Long-Term Support For Faculty Through Graduate Student Instructor Professional Development, Nathan Wakefield, Karina Uhing, Mitchell Hamidi

Department of Mathematics: Faculty Publications

Improving university-level instruction is an important step to improving instruction at all levels, and in order to improve university-level instruction, instructors need to master more effective models of instruction and be able to draw on education literature as they continue to develop as instructors. Well-trained, informed instructors are well equipped to be agents of change when they take on faculty positions. However, this mastery requires training and practice.

Backstepping And Sequential Predictors For Control Systems, Jerome Avery Weston

LSU Doctoral Dissertations

We provide new methods in mathematical control theory for two significant classes of control systems with time delays, based on backstepping and sequential prediction. Our bounded backstepping results ensure global asymptotic stability for partially linear systems with an arbitrarily large number of integrators. We also build sequential predictors for time-varying linear systems with time-varying delays in the control, sampling in the control, and time-varying measurement delays. Our bounded backstepping results are novel because of their use of converging-input-converging-state conditions, which make it possible to solve feedback stabilization problems under input delays and under boundedness conditions on the feedback control. Our …

Spectra Of Quantum Trees And Orthogonal Polynomials, Zhaoxia Wang

LSU Doctoral Dissertations

We investigate the spectrum of regular quantum-graph trees, where the edges are endowed with a Schr\"odinger operator with self-adjoint Robin vertex conditions. It is known that, for large eigenvalues, the Robin spectrum approaches the Neumann spectrum. In this research, we compute the lower Robin spectrum. The spectrum can be obtained from the roots of a sequence of orthogonal polynomials involving two variables. As the length of the quantum tree increases, the spectrum approaches a band-gap structure. We find that the lowest band tends to minus infinity as the Robin parameter increases, whereas the rest of the bands remain positive. Unexpectedly, …

Discrete-Time Hybrid Control In Borel Spaces: Average Cost Optimality Criterion, Héctor Jasso-Fuentes, José-Luis Menaldi, Tomás Prieto-Rumeau, Maurice Robin

Mathematics Faculty Research Publications

This paper addresses an optimal hybrid control problem in discrete-time with Borel state and action spaces. By hybrid we mean that the evolution of the state of the system may undergo deep changes according to structural modifications of the dynamic. Such modifications occur either by the position of the state or by means of the controller's actions. The optimality criterion is of a long-run ratio-average (or ratio-ergodic) type. We provide the existence of optimal average policies for this hybrid control problem by analyzing an associated dynamic programming equation. We also show that this problem can be translated into a standard …

Weak Galerkin Finite Element Method With Mixed Boundary Conditions, Saqib Hussain

Theses and Dissertations

Mixed boundary conditions are practical situations that appear in most potential and physics problems. In this dissertation, a weak Galerkin (WG) finite element method is proposed and analyzed for the general elliptic equation with mixed boundary conditions. Furthermore, we developed a modified weak Galerkin (MWG) method for the second order elliptic problem with mixed boundary conditions. While keeping the same accuracy, the modified weak Galerkin method reduces the degree of freedom of the original weak Galerkin method by eliminating unknowns associated with element boundaries. Optimal order error estimates are established in both a discrete $H^1$ norm and the standard $L^2$ …

Transport Phenomena In Field Effect Transistors, Ryan M. Evans, Arvind Balijepalli, Anthony Kearsley

Biology and Medicine Through Mathematics Conference

No abstract provided.

Quantitative Electroencephalography For Detecting Concussions, Sara Krehbiel, Kathy Hoke, Joanna Wares

Biology and Medicine Through Mathematics Conference

No abstract provided.

Inventory Model With Ramp-Type Demand And Price Discount On Back Order For Deteriorating Items Under Partial Backlogging, Sumit Saha, Nabendu Sen, Biman K. Nath

Applications and Applied Mathematics: An International Journal (AAM)

Modeling of inventory problems provides a good insight to retailers and distributors to maintain stock of different items such as seasonal products, perishable goods and daily useable goods etc. The deterioration of all these items exists to a certain extent due to several reasons like mishandling, evaporation, decay, environmental conditions, transportation etc. It is found from the literature that previously many of the researchers have developed inventory model ignoring deterioration and drawn conclusion. In the absence of deterioration parameter, an inventory model cannot be completely realistic. In this paper, we have made an attempt to extend an inventory model with …

An Accelerate Process For The Successive Approximations Method In The Case Of Monotonous Convergence, A. Laouar, I. Mous

Applications and Applied Mathematics: An International Journal (AAM)

We study an iterative process to accelerate the successive approximations method in a monotonous convergence framework. It consists in interrupting the sequence of the successive approximations method produced at the kth iteration and substituting it by a combination of the element of the sequence produced at the iterate k + 1 and an extrapolation vector. The latter uses a parameter which can be calculated mathematically. We illustrate numerically this process by studying a freeboundary problems class.

Solution For System Of Fractional Partial Differential Equations, D. B. Dhaigude, Swati N. Kanade, C. D. Dhaigude

Applications and Applied Mathematics: An International Journal (AAM)

The purpose of this article is to discuss solutions of different initial value problems (IVPs) for system of fractional differential equations. These equations appear in physical processes such as transportation and anomalous diffusion. The iteration method is successfully developed and series solution of IVPs at hand are obtained which converges to a function known as solution function of the IVPs. Graphical representation of solution of some IVPs are given using Mathematical software “MATLAB”.

Method Of Deriving Companion Identities Associating Q-Series, Keshav P. Yadav, Adarsh Kumar

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, we have established two theorems by making use of Euler’s q-derivative and qshifted operators for a function of one variable and also for function of two variables. We derived several companion identities by applying these theorems on some known q-series identities. We deduced several special cases which are also the companion identities in the last section of the paper.

A Mathematical Study For The Existence And Survival Of Human Population In A Polluted Environment, Manju Agarwal, Preeti _

Applications and Applied Mathematics: An International Journal (AAM)

Rapidly rising population and increasing urbanization have the potential for producing a high level of pollution. Pollutants have the ability to change the distributions of patterns of plants and animals. Some of the main pollutant categories are water pollutants, air pollution, pesticides, and radioactive waste. Most abundantly toxicants are produced by the chemical and medical industries. We used food crops that are produced by using pesticide and herbicides, etc. Due to the enormous variety of toxic substances are present in the atmosphere, it is challenging task to determine the potential ecological and human health risk. Keeping all these things in …

On Indexed Absolute Matrix Summability Of An Infinite Series, Lakshmi N. Mishra, P. K. Das, P. Samanta, M. Misra, U. K. Misra

Applications and Applied Mathematics: An International Journal (AAM)

Some results have been established on absolute index Riesz summability factor of an infinite series. Furthermore, these kind of results can be extended by taking other parameters and an absolute index matrix summability factor of an infinite series or some weaker conditions. In the present paper a new result on generalized absolute index matrix summability factor of an infinite series has been established.

A Numerical Method For Functional Hammerstein Integro-Differential Equations, L. Saeedi, A. Tari

Applications and Applied Mathematics: An International Journal (AAM)

In this paper, a numerical method is presented to solve functional Hammerstein integro-differential equations. The presented method combines the successive approximations method with trapezoidal quadrature rule and natural cubic spline interpolation to solve the mentioned equations. The existence and uniqueness of the problem is also investigated. The convergence and numerical stability of the problem are proved, and finally, the accuracy of the method is verified by presenting some numerical computations.

System Reliability Using Generalized Intuitionistic Fuzzy Rayleigh Lifetime Distribution, Ali Ebrahimnejad, Ezzatallah B. Jamkhaneh

Applications and Applied Mathematics: An International Journal (AAM)

Reliability analysis as one of the important research topics in engineering has been researched by a number of authors. Reliability in classical distributions is based on precise parameters. It is usually assumed that parameters of distributions are precise real numbers. However, in the real world, the data sometimes cannot be measured and recorded precisely. In this paper, the concept of fuzzy reliability is extended by the idea of generalized intuitionistic fuzzy reliability. We investigate the reliability characteristics of systems using Rayleigh lifetime distribution, in which the lifetime parameter is assumed to be generalized intuitionistic fuzzy number. Generalized intuitionistic fuzzy reliability, …

Generalized Problem Of Thermal Bending Analysis In The Cartesian Domain, V. S. Kulkarni, Vinayaki Parab

Applications and Applied Mathematics: An International Journal (AAM)

This is an attempt for mathematical formulation and general analytical solution of the most generalized thermal bending problem in the Cartesian domain. The problem has been formulated in the context of non-homogeneous transient heat equation subjected to Robin’s boundary conditions. The general solution of the generalized thermoelastic problem has been discussed for temperature change, displacements, thermal stresses, deflection, and deformation. The most important feature of this work is any special case of practical interest may be readily obtained by this most generalized mathematical formulation and its analytical solution. There are 729 such combinations of possible boundary conditions prescribed on parallelepiped …