High-Order Positivity-Preserving L2-Stable Spectral Collocation Schemes For The 3-D Compressible Navier-Stokes Equations,
2021
Old Dominion University
High-Order Positivity-Preserving L2-Stable Spectral Collocation Schemes For The 3-D Compressible Navier-Stokes Equations, Johnathon Keith Upperman
Mathematics & Statistics Theses & Dissertations
High-order entropy stable schemes are a popular method used in simulations with the compressible Euler and Navier-Stokes equations. The strength of these methods is that they formally satisfy a discrete entropy inequality which can be used to guarantee L2 stability of the numerical solution. However, a fundamental assumption that is explicitly or implicitly used in all entropy stability proofs available in the literature for the compressible Euler and Navier-Stokes equations is that the thermodynamic variables (e.g., density and temperature) are strictly positive in the entire space{time domain considered. Without this assumption, any entropy stability proof for a numerical scheme …
Finite Difference Schemes For Integral Equations With Minimal Regularity Requirements,
2021
Old Dominion University
Finite Difference Schemes For Integral Equations With Minimal Regularity Requirements, Wesley Cameron Davis
Mathematics & Statistics Theses & Dissertations
Volterra integral equations arise in a variety of applications in modern physics and engineering, namely in interactions that contain a memory term. Classical formulations of these problems are largely inflexible when considering non-homogeneous media, which can be problematic when considering long term interactions of real-world applications. The use of fractional derivative and integral terms naturally relax these restrictions in a natural way to consider these problems in a more general setting. One major drawback to the use of fractional derivatives and integrals in modeling is the regularity requirement for functions, where we can no longer assume that functions are as …
Electrohydrodynamic Simulations Of Capsule Deformation Using A Dual Time-Stepping Lattice Boltzmann Scheme,
2021
Old Dominion University
Electrohydrodynamic Simulations Of Capsule Deformation Using A Dual Time-Stepping Lattice Boltzmann Scheme, Charles Leland Armstrong
Mathematics & Statistics Theses & Dissertations
Capsules are fluid-filled, elastic membranes that serve as a useful model for synthetic and biological membranes. One prominent application of capsules is their use in modeling the response of red blood cells to external forces. These models can be used to study the cell’s material properties and can also assist in the development of diagnostic equipment. In this work we develop a three dimensional model for numerical simulations of red blood cells under the combined influence of hydrodynamic and electrical forces. The red blood cell is modeled as a biconcave-shaped capsule suspended in an ambient fluid domain. Cell deformation occurs …
Dynamic Parameter Estimation From Partial Observations Of The Lorenz System,
2021
CUNY Hunter College
Dynamic Parameter Estimation From Partial Observations Of The Lorenz System, Eunice Ng
Theses and Dissertations
Recent numerical work of Carlson-Hudson-Larios leverages a nudging-based algorithm for data assimilation to asymptotically recover viscosity in the 2D Navier-Stokes equations as partial observations on the velocity are received continuously-in-time. This "on-the-fly" algorithm is studied both analytically and numerically for the Lorenz equations in this thesis.
Smooth Global Approximation For Continuous Data Assimilation,
2021
CUNY Hunter College
Smooth Global Approximation For Continuous Data Assimilation, Kenneth R. Brown
Theses and Dissertations
This thesis develops the finite element method, constructs local approximation operators, and bounds their error. Global approximation operators are then constructed with a partition of unity. Finally, an application of these operators to data assimilation of the two-dimensional Navier-Stokes equations is presented, showing convergence of an algorithm in all Sobolev topologies.
The Exact Factorization Equations For One- And Two-Level Systems,
2021
CUNY Hunter College
The Exact Factorization Equations For One- And Two-Level Systems, Bart Rosenzweig
Theses and Dissertations
Exact Factorization is a framework for studying quantum many-body problems. This decomposes the wavefunctions of such systems into conditional and marginal components. We derive corresponding evolution equations for molecular systems whose conditional electronic subsystems are described by one or two Born-Oppenheimer levels and develop a program for their mathematical study.
Gradient Estimates And The Fundamental Solution For Higher-Order Elliptic Systems With Lower-Order Terms,
2021
University of Arkansas, Fayetteville
Gradient Estimates And The Fundamental Solution For Higher-Order Elliptic Systems With Lower-Order Terms, Michael J. Duffy Jr.
Graduate Theses and Dissertations
Here we generalize the higher-order divergence-form elliptic differential equations studied by Barton in [4] by the inclusion of certain lower-order terms. The methods used here compare to those used in [4], with the addition of further Sobolev-type estimates to handle included lower-order terms. In section 3 we derive a Caccioppoli inequality in which we bound the L2 norm of the mth order gradient, in terms of the L2 norm of the solution. In section 5 we adapt some of the ideas from [9] to derive Lp bounds on gradients of solutions as a substitute for a reverse Holder inequality. Finally …
A Computational Model Of Arterial Thrombus Mechanics In Stenotic Channels,
2021
Florida Institute of Technology
A Computational Model Of Arterial Thrombus Mechanics In Stenotic Channels, Elise Kole Aspray
Theses and Dissertations
Platelet aggregation is one of the major components of blood clotting. The proximal cause of most heart attacks and many strokes is the rapid formation of a blood clot (thrombus) in response to the rupture or erosion of an arterial atherosclerotic plaque. In the context of a stenotic artery (i.e., an artery whose lumen is partially blocked by the plaque) understanding how the thrombus forms presents additional challenges because of the extremely high shear rates and stresses present as a consequence of the constriction. In this dissertation, we use a two-phase continuum model to investigate the stability of an existing …
Modernization Of Scienttific Mathematics Formula In Technology,
2021
University of Nebraska - Lincoln
Modernization Of Scienttific Mathematics Formula In Technology, Iwasan D. Kejawa Ed.D, Prof. Iwasan D. Kejawa Ed.D
Department of Mathematics: Faculty Publications
Abstract
Is it true that we solve problem using techniques in form of formula? Mathematical formulas can be derived through thinking of a problem or situation. Research has shown that we can create formulas by applying theoretical, technical, and applied knowledge. The knowledge derives from brainstorming and actual experience can be represented by formulas. It is intended that this research article is geared by an audience of average knowledge level of solving mathematics and scientific intricacies. This work details an introductory level of simple, at times complex problems in a mathematical epidermis and computability and solvability in a Computer Science. …
An Efficient Transformer-Based Model For Vietnamese Punctuation Prediction,
2021
Singapore Management University
An Efficient Transformer-Based Model For Vietnamese Punctuation Prediction, Hieu Tran, Cuong V. Dinh, Hong Quang Pham, Binh T. Nguyen
Research Collection School Of Computing and Information Systems
In both formal and informal texts, missing punctuation marks make the texts confusing and challenging to read. This paper aims to conduct exhaustive experiments to investigate the benefits of the pre-trained Transformer-based models on two Vietnamese punctuation datasets. The experimental results show our models can achieve encouraging results, and adding Bi-LSTM or/and CRF layers on top of the proposed models can also boost model performance. Finally, our best model can significantly bypass state-of-the-art approaches on both the novel and news datasets for the Vietnamese language. It can gain the corresponding performance up to 21.45%21.45% and 18.27%18.27% in the overall F1-scores.
Finding New Limit Points Of Mahler Measure By Methods Of Missing Data Restoration,
2021
Research engineer, IECL, University of Lorraine
Finding New Limit Points Of Mahler Measure By Methods Of Missing Data Restoration, Jean-Marc Sac-Epee J.M Sac-Epee, Souad El Otmani, Armand Maul, Georges Rhin
BAU Journal - Science and Technology
It is well known that the set of Mahler measures of single variable polynomial has limit points of which a list established by D. Boyd and M. Mossinghoff has been extended through approaches based on genetic algorithms. In this paper, we wish to further extend the list of known limit points by adapting a method of missing data restoration.
Universal Biological Motions For Educational Robot Theatre And Games,
2021
Portland State University
Universal Biological Motions For Educational Robot Theatre And Games, Rajesh Venkatachalapathy, Martin Zwick, Adam Slowik, Kai Brooks, Mikhail Mayers, Roman Minko, Tyler Hull, Bliss Brass, Marek Perkowski
Complex Systems Faculty Publications and Presentations
Paper presents a concept that is new to robotics education and social robotics. It is based on theatrical games, in motions for social robots and animatronic robots. Presented here motion model is based on Drift Differential Model from biology and Fokker-Planck equations. This model is used in various areas of science to describe many types of motion. The model was successfully verified on various simulated mobile robots and a motion game of three robots called "Mouse and Cheese."
Dpp: Deep Predictor For Price Movement From Candlestick Charts,
2021
National Chung Hsing University, Taipei
Dpp: Deep Predictor For Price Movement From Candlestick Charts, Chih-Chieh Hung, Ying-Ju (Tessa) Chen
Mathematics Faculty Publications
Forecasting the stock market prices is complicated and challenging since the price movement is affected by many factors such as releasing market news about earnings and profits, international and domestic economic situation, political events, monetary policy, major abrupt affairs, etc. In this work, a novel framework: deep predictor for price movement (DPP) using candlestick charts in the stock historical data is proposed. This framework comprises three steps: 1. decomposing a given candlestick chart into sub-charts; 2. using CNN-autoencoder to acquire the best representation of sub-charts; 3. applying RNN to predict the price movements from a collection of sub-chart representations. An …
Grizzly Bears Mortalities And The Survival Of The Species,
2021
University of Minnesota - Morris
Grizzly Bears Mortalities And The Survival Of The Species, Courtney Swanson
Senior Seminars and Capstones
In this paper we aim to understand what is happening in the grizzly bear population mortalities from the year 2010 to 2020. We are performing Classical and Regression Tree (CART) methods and Correspondence Analysis on data provided by the U.S. Geological Survey (USGS). We found certain variables in the data set to be important through CART methods. Correspondence Analysis then allowed us to compare these variables to determine their relationships and association to one another. Most of the grizzly bear deaths are human caused and mainly over land and resources such as food and habitat. This aligns with some of …
Optimal Stopping Problems For A Family Of Continuous-Time Markov Processes,
2021
CINVESTAV-IPN
Optimal Stopping Problems For A Family Of Continuous-Time Markov Processes, Héctor Jasso-Fuentes, Jose-Luis Menaldi, Fidel Vásquez-Rojas
Mathematics Faculty Research Publications
In this paper we study the well-know optimal stopping problem applied to a general family of continuous-time Markov process. The approach to follow is merely analytic and it is based on the characterization of stopping problems through the study of a certain variational inequality; namely one solution of this inequality will coincide with the optimal value of the stopping problem. In addition, by means of this characterization, it is possible to find the so-named continuation region, and as a byproduct obtaining the optimal stopping time. The most of the material is based on the semigroup theory, infinitesimal generators and resolvents. …
Qualitative Analysis Of A Modified Leslie-Gower Predator-Prey Model With Weak Allee Effect Ii,
2021
Babasaheb Bhimrao Ambedkar University
Qualitative Analysis Of A Modified Leslie-Gower Predator-Prey Model With Weak Allee Effect Ii, Manoj K. Singh, B. S. Bhadauria
Applications and Applied Mathematics: An International Journal (AAM)
The article aims to study a modified Leslie-Gower predator-prey model with Allee effect II, affecting the functional response with the assumption that the extent to which the environment provides protection to both predator and prey is the same. The model has been studied analytically as well as numerically, including stability and bifurcation analysis. Compared with the predator-prey model without Allee effect, it is found that the weak Allee effect II can bring rich and complicated dynamics, such as the model undergoes to a series of bifurcations (Homoclinic, Hopf, Saddle-node and Bogdanov-Takens). The existence of Hopf bifurcation has been shown for …
Anti-Synchronization Scheme For The Stability Analysis Of A Newly Designed Hamiltonian Chaotic System Based On Hénon-Heiles Model Using Adaptive Control Method,
2021
Jamia Millia Islamia
Anti-Synchronization Scheme For The Stability Analysis Of A Newly Designed Hamiltonian Chaotic System Based On Hénon-Heiles Model Using Adaptive Control Method, Ayub Khan, Anu Jain, Santosh Kaushik, Manoj Kumar, Harindri Chaudhary
Applications and Applied Mathematics: An International Journal (AAM)
In this paper, a systematic approach to investigate the anti-synchronization among identical Hamiltonian chaotic systems has been proposed by using adaptive control method (ACM). Initially an adaptive controller and parameter update law are described to achieve asymptotical stability of state variables of given system with uncertain parameters using Lyapunov stability theory (LST). In addition, numerical simulations using MATLAB software are performed to validate the efficacy and effectiveness of the designed technique. Moreover, the proposed technique has numerous applications in encryption and secure communication.
Maximum Difference Extreme Difference Method For Finding The Initial Basic Feasible Solution Of Transportation Problems,
2021
African Institute for Mathematical Sciences
Maximum Difference Extreme Difference Method For Finding The Initial Basic Feasible Solution Of Transportation Problems, Ridwan Raheem Lekan, Lord Clifford Kavi, Nancy Ann Neudauer
Applications and Applied Mathematics: An International Journal (AAM)
A Transportation Problem can be modeled using Linear Programming to determine the best transportation schedule that will minimize the transportation cost. Solving a transportation problem requires finding the Initial Basic Feasible Solution (IBFS) before obtaining the optimal solution. We propose a new method for finding the IBFS called the Maximum Difference Extreme Difference Method (MDEDM) which yields an optimal or close to the optimal solution. We also investigate the computational time complexity of MDEDM, and show that it is O(mn).
A High Order Finite Difference Method To Solve The Steady State Navier-Stokes Equations,
2021
Prairie View A&M University
A High Order Finite Difference Method To Solve The Steady State Navier-Stokes Equations, Nihal J. Siriwardana, Saroj P. Pradhan
Applications and Applied Mathematics: An International Journal (AAM)
In this article, we develop a fourth order finite difference method to solve the system of steady state Navier-Stokes equations and apply it to the benchmark problem known as the square cavity flow problem. The numerical results of 𝑢-velocity components and 𝑣-velocity components obtained at the center of the cavity are compared with the results obtained by the method developed by Greenspan and Casulli to solve the time dependent system of Navier-Stokes equations. The method described in this article is easy to implement and it has been shown to be more efficient and stable than the method by Greenspan and …
Casson Fluid Flow Past On Vertical Cylinder In The Presence Of Chemical Reaction And Magnetic Field,
2021
Babu Banarasi Das University
Casson Fluid Flow Past On Vertical Cylinder In The Presence Of Chemical Reaction And Magnetic Field, Gaurav Kumar, S.M.K. Rizvi
Applications and Applied Mathematics: An International Journal (AAM)
In this paper, we have examined the behavior of unsteady flow of a viscous, incompressible and electrically conducting Casson fluid past an impulsively started vertical cylinder with variable temperature and mass diffusion in the presence of transversely applied uniform magnetic field and chemical reaction. The temperature and concentration level near the surface increase linearly with time. The governing equations of non-dimensional form of flow model have been solved numerically by using Crank-Nicolson implicit finite difference method. The velocity profile is discussed with the help of graphs drawn for different parameters like Casson fluid parameter, Prandtl number, chemical reaction parameter and …
