Open Access. Powered by Scholars. Published by Universities.®
- Discipline
-
- Statistics and Probability (412)
- Engineering (17)
- Computer Sciences (7)
- Electrical and Computer Engineering (5)
- Biology (4)
-
- Chemical Engineering (4)
- Life Sciences (4)
- Mechanical Engineering (4)
- Petroleum Engineering (4)
- Aerospace Engineering (3)
- Earth Sciences (3)
- Geology (3)
- Numerical Analysis and Scientific Computing (3)
- Civil and Environmental Engineering (2)
- Geological Engineering (2)
- Applied Mathematics (1)
- Applied Statistics (1)
- Architectural Engineering (1)
- Architecture (1)
- Biochemical and Biomolecular Engineering (1)
- Chemistry (1)
- Operations Research, Systems Engineering and Industrial Engineering (1)
- Keyword
-
- Oscillation (22)
- Time scales (14)
- Time scale (11)
- Continuum (10)
- Inverse limit (8)
-
- Navier-Stokes Equations (8)
- Periodicity (6)
- Boundary value problem (5)
- Energy Stability (5)
- Indecomposable continuum (5)
- Time Scales (5)
- Variational inequality (5)
- Delay (4)
- Energy stability (4)
- Existence (4)
- Global Attractor (4)
- Global stability (4)
- Hyperspace (4)
- Multivalued mapping (4)
- Open (4)
- Positive solution (4)
- Time Scale (4)
- Article (3)
- Boundary Layer (3)
- Boundedness (3)
- D-complete topological spaces (3)
- Dynamic equation (3)
- Dynamic equations (3)
- Error analysis (3)
- Finite element method (3)
- Publication Year
Articles 331 - 360 of 440
Full-Text Articles in Mathematics
On The Existence Of Nontrivial Solutions To Some Elliptic Variational Inequalities, Vy Khoi Le, Klaus Schmitt
On The Existence Of Nontrivial Solutions To Some Elliptic Variational Inequalities, Vy Khoi Le, Klaus Schmitt
Mathematics and Statistics Faculty Research & Creative Works
The paper is concerned with the existence of nontrivial solutions of the obstacle problem: u ε K: ∫Ω ▽u▽ (v - u) dx - λ ∫ Ω u (v - u) dx ≥ ∫ Ω p (x, u) (v - u) dx ∀x ε K, where K = {v ε Ho1(Ω): v ≤ Ψ a.e. on Ω}. By using a generalized mountain pass theorem for inequalities, we prove, subject to some restrictions on the obstacle Ψ, the existence of nontrivial solutions of the above inequality.
Canonical Thurston Obstructions, Kevin M. Pilgrim
Canonical Thurston Obstructions, Kevin M. Pilgrim
Mathematics and Statistics Faculty Research & Creative Works
We refine Douady and Hubbard's proof of Thurston's topological characterization of rational functions by proving the following theorem. Let f: S2→S2 be a branched covering with finite postcritical set Pf and hyperbolic orbifold. Let Γc denote the set of all homotopy classes γ of nonperipheral, simple closed curves in S2-Pf such that the length of the unique geodesic homotopic to γ tends to zero under iteration of the Thurston map induced by f on Teichmüller space. Then either Γc is empty, and f is equivalent to a rational function, or else Γc is a Thurston obstruction. © 2001 Academic Press.
A Degree Of Nonlocal Connectedness, J. J. Charatonik, W. J. Charatonik
A Degree Of Nonlocal Connectedness, J. J. Charatonik, W. J. Charatonik
Mathematics and Statistics Faculty Research & Creative Works
To any continuum X weassign an ordinal number (or the symbol ∞) s(X), called the degree of nonlocal connectedness of X. We show that (1) the degree cannot be increased under continuous surjections; (2) for hereditarily unicoherent continua X, the degree of a subcontinuum of X is less than or equal to s(X); (3) s(C(X)) ≤ s(X), where C(X) denotes the hyperspace of subcontinua of a continuum X. We also investigate the degrees of Cartesian products and inverse limits. As an application weconstruct an uncountable family of metric continua X homeomorphic to C(X).
Boundary Layers In Channel Flow With Injection And Suction, R. Temam, X. Wang
Boundary Layers In Channel Flow With Injection And Suction, R. Temam, X. Wang
Mathematics and Statistics Faculty Research & Creative Works
We present a rigorous result regarding the boundary layer associated with the incompressible Newtonian channel flow with injection and suction. © 2000 Elsevier Science Ltd. All rights reserved.
Residual Properties And Almost Equicontinuity, Ethan Akin, Eli Glasner
Residual Properties And Almost Equicontinuity, Ethan Akin, Eli Glasner
Mathematics and Statistics Faculty Research & Creative Works
A property P of a compact dynamical system (X, f) is called a residual property if it is inherited by factors, almost one-to-one lifts and surjective inverse limits. Many transitivity properties are residual. Weak disjointness from all property P systems is a residual property provided P is a residual property stronger than transitivity. Here two systems are weakly disjoint when their product is transitive. Our main result says that for an almost equicontinuous system (X, f) with associated monothetic group Λ, (X, f) is weakly disjoint from all P systems if the only P systems upon which Λ acts are …
Power Connector, Stephen L. Clark, Joseph B. Shuey, Jose L. Ortega, John B. Brown Iii
Power Connector, Stephen L. Clark, Joseph B. Shuey, Jose L. Ortega, John B. Brown Iii
Mathematics and Statistics Faculty Research & Creative Works
A pair of mating connectors includes a receptacle having an insulative housing and at least one conductive receptacle contact with a pair of spaced walls forming a plug contact receiving space. The plug connector has an insulative housing and at least one conductive contact having a pair of spaced walls which converge to form a projection engageable in the plug receiving space of the receptacle contact. In each case, the spaced walls are joined by a bridging structure that unites the walls. The plug and receptacle contacts are retained in the respective housings by engagement of opposed lateral edge portions …
Openness Of Induced Projections, J. J. Charatonik, W. J. Charatonik, Alejandro Illanes
Openness Of Induced Projections, J. J. Charatonik, W. J. Charatonik, Alejandro Illanes
Mathematics and Statistics Faculty Research & Creative Works
For continua X and Y it is shown that if the projection f : X x Y ->X has its induced mapping C(f) open, then X is C*-smooth. As a corollary, a characterization of dendrites in these terms is obtained.
A Census Of Rational Maps, Eva Brezin, Rosemary Byrne, Joshua Levy, Kevin M. Pilgrim, Kelly Plummer
A Census Of Rational Maps, Eva Brezin, Rosemary Byrne, Joshua Levy, Kevin M. Pilgrim, Kelly Plummer
Mathematics and Statistics Faculty Research & Creative Works
We discuss the general combinatorial, topological, algebraic, and dynamical issues underlying the enumeration of postcritically finite rational functions, regarded as holomorphic dynamical systems on the Riemann sphere. We present findings from our creation of a census of all degree two and three hyperbolic nonpolynomial maps with four or fewer postcritical points. Our data is tabulated in detail at. © 1999 American Mathematical Society.
Dendrites And Light Open Mappings, J. J. Charatonik, W. J. Charatonik, Pawel Krupski
Dendrites And Light Open Mappings, J. J. Charatonik, W. J. Charatonik, Pawel Krupski
Mathematics and Statistics Faculty Research & Creative Works
It is shown that a metric continuum X is a dendrite if and only if for every compact space Y and for every light open mapping f : Y ->f(Y ) such that X c f(Y ) there is a copy X1 of X in Y for which the restriction fjX1 : X1 ->X is a homeomorphism. Another characterization of dendrites in terms of continuous selections of multivalued functions is also obtained.
Inverse Limits On [0,1] Using Piecewise Linear Unimodal Bonding Maps, William Thomas Ingram
Inverse Limits On [0,1] Using Piecewise Linear Unimodal Bonding Maps, William Thomas Ingram
Mathematics and Statistics Faculty Research & Creative Works
In this paper we investigate inverse limits on [0,1] using a single bonding map chosen from a two-parameter family of piecewise linear unimodal bonding maps. This investigation focuses on the parameter values at the boundary between a hereditarily decomposable inverse limit and an inverse limit containing an indecomposable continuum. © 1999 American Mathematical Society.
Remarks On The Prandtl Equation For A Permeable Wall, R. Temam, X. Wang
Remarks On The Prandtl Equation For A Permeable Wall, R. Temam, X. Wang
Mathematics and Statistics Faculty Research & Creative Works
The goal of this article is to study the boundary layer for a flow in a channel with permeable walls. Observing that the Prandtl equation can be solved almost exactly in this case, we are able to derive rigorously a number of results concerning the boundary layer and the convergence of the Navier-Stokes equations to the Euler equations. We indicate also how to derive higher order terms in the inner and outer expansions with respect to the kinematic viscosity v.
Openness And Monotoneity Of Induced Mappings, W. J. Charatonik
Openness And Monotoneity Of Induced Mappings, W. J. Charatonik
Mathematics and Statistics Faculty Research & Creative Works
It is shown that for locally connected continuum X if the induced mapping C(f) : C(X) ->C(Y) is open, then f is monotone. As a corollary it follows that if the continuum X is hereditarily locally connected and C(f) is open, then f is a homeomorphism. An example is given to show that local connectedness is essential in the result.
Invariant Measures For Set-Valued Dynamical Systems, Walter Miller, Ethan Akin
Invariant Measures For Set-Valued Dynamical Systems, Walter Miller, Ethan Akin
Mathematics and Statistics Faculty Research & Creative Works
A continuous map on a compact metric space, regarded as a dynamical system by iteration, admits invariant measures. For a closed relation on such a space, or, equivalently, an upper semicontinuous set-valued map, there are several concepts which extend this idea of invariance for a measure. We prove that four such are equivalent. In particular, such relation invariant measures arise as projections from shift invariant measures on the space of sample paths. There is a similarly close relationship between the ideas of chain recurrence for the set-valued system and for the shift on the sample path space. ©1999 American Mathematical …
Attractors For Non-Compact Semigroups Via Energy Equations, Ioana Moise, Ricardo Rosa, Xiaoming Wang
Attractors For Non-Compact Semigroups Via Energy Equations, Ioana Moise, Ricardo Rosa, Xiaoming Wang
Mathematics and Statistics Faculty Research & Creative Works
The energy-equation approach used to prove the existence of the global attractor by establishing the so-called asymptotic compactness property of the semigroup is considered, and a general formulation that can handle a number of weakly damped hyperbolic equations and parabolic equations on either bounded or unbounded spatial domains is presented. as examples, three specific and physically relevant problems are considered, namely the flows of a second-grade fluid, the flows of a Newtonian fluid in an infinite channel past an obstacle, and a weakly damped, forced Korteweg-de Vries equation on the whole line.
Attractor Dimension Estimates For Two-Dimensional Shear Flows, Charles R. Doering, Xiaoming Wang
Attractor Dimension Estimates For Two-Dimensional Shear Flows, Charles R. Doering, Xiaoming Wang
Mathematics and Statistics Faculty Research & Creative Works
We study the large time behavior of boundary and pressure-gradient driven incompressible fluid flows in elongated two-dimensional channels with emphasis on estimates for their degrees of freedom, i.e., the dimension of the attractor for the solutions of the Navier-Stokes equations. for boundary driven shear flows and flux driven channel flows we present upper bounds for the degrees of freedom of the form ca Re3/2 where c is a universal constant, a denotes the aspect ratio of the channel (length/width), and Re is the Reynolds number based on the channel width and the imposed "outer" velocity scale. for fixed pressure …
Atomoicity Of Mappings, J. J. Charatonik, W. J. Charatonik
Atomoicity Of Mappings, J. J. Charatonik, W. J. Charatonik
Mathematics and Statistics Faculty Research & Creative Works
A mapping f:X→Y between continua X and Y is said to be atomic at a subcontinuumK of the domain X provided that f(K) is nondegenerate and K=f-1(f(K)). The set of subcontinua at which a given mapping is atomic, considered as a subspace of the hyperspace of all subcontinua of X, is studied. The introduced concept is applied to get new characterizations of atomic and monotone mappings. Some related questions are asked.
Arc Approximation Property And Confluence Of Induced Mappings, W. J. Charatonik
Arc Approximation Property And Confluence Of Induced Mappings, W. J. Charatonik
Mathematics and Statistics Faculty Research & Creative Works
We say that a continuum X has the arc approximation property if every subcontinuum K of X is the limit of a sequence of arcwise connected subcontinua of X all containing a fixed point of K. This property is applied to exhibit a class of continua Y such that confluence of a mapping f : X - Y implies confluence of the induced mappings 2^f : 2^x - @^y and C(f) : C(x) - C(y). The converse implications are studied and similar interrelations are considered for some other classes of mappings, related to confluent ones.
Exponential Dichotomy And Mild Solutions Of Nonautonomous Equations In Banach Spaces, Y. Latushkin, Timothy W. Randolph, R. Schnaubelt
Exponential Dichotomy And Mild Solutions Of Nonautonomous Equations In Banach Spaces, Y. Latushkin, Timothy W. Randolph, R. Schnaubelt
Mathematics and Statistics Faculty Research & Creative Works
We prove that the exponential dichotomy of a strongly continuous evolution family on a Banach space is equivalent to the existence and uniqueness of continuous bounded mild solutions of the corresponding inhomogeneous equation. This result addresses nonautonomous abstract Cauchy problems with unbounded coefficients. The technique used involves evolution semigroups. Some applications are given to evolution families on scales of Banach spaces arising in center manifolds theory. © 1998 Plenum Publishing Corporation.
Some Harmonic N-Slit Mappings, Michael Dorff
Some Harmonic N-Slit Mappings, Michael Dorff
Mathematics and Statistics Faculty Research & Creative Works
The class SH consists of univalent, harmonic, and sense-preserving functions f in the unit disk, Δ, such that f = h+ḡ where h(z) = z + ∑2∞ akzk g(z) = ∑1∞ bkzk. SHO will denote the subclass with b1 = 0. We present a collection of n-slit mappings (n ≥ 2) and prove that the 2-slit mappings are in SH while for n ≥ 3 the mappings are in SHO. Finally, we show that these mappings establish the sharpness of a previous theorem by Clunie and Sheil-Small while disproving a conjecture about the inner mapping radius. ©1998 American Mathematical Society.
Further Properties Of An Extremal Set Of Uniqueness, David E. Grow, Matt Insall
Further Properties Of An Extremal Set Of Uniqueness, David E. Grow, Matt Insall
Mathematics and Statistics Faculty Research & Creative Works
Consider the circle group T = R mod 2_ as the interval [0, 1). Then each x 2 T has a binary expansion: x =P1 k=1 xk2−k where each xk is 0 or 1. Let S be the set of x with a binary expansionsuch that the number of 1's does not exceed the number of the leading zeros by more than one. The authors prove that the countable compact set S cannot be expressed as the union of a finite number of Dirichlet sets.
The Convergence Of The Solutions Of The Navier-Stokes Equations To That Of The Euler Equations, R. Temam, X. Wang
The Convergence Of The Solutions Of The Navier-Stokes Equations To That Of The Euler Equations, R. Temam, X. Wang
Mathematics and Statistics Faculty Research & Creative Works
In this article, we establish partial results concerning the convergence of the solutions of the Navier-Stokes equations to that of the Euler equations. Convergence is proved in space dimension two under a physically reasonable assumption, namely that the gradient of the pressure remains bounded at the boundary as the Reynolds number converges to infinity.
Attractors For Nonautonomous Nonhomogeneous Navier-Stokes Equations, A. Miranville, X. Wang
Attractors For Nonautonomous Nonhomogeneous Navier-Stokes Equations, A. Miranville, X. Wang
Mathematics and Statistics Faculty Research & Creative Works
In this paper our aim is to derive an upper bound on the dimension of the attractor of the family of processes associated to the Navier-Stokes equations with nonhomogeneous boundary conditions depending on time. We consider two-dimensional flows with prescribed quasiperiodic (in time) tangential velocity at the boundary, and obtain an upper bound which is polynomial with respect to the viscosity.
Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley
Elimination Of Supply Harmonics, Stephen L. Clark, P. Famouri, W. L. Cooley
Mathematics and Statistics Faculty Research & Creative Works
The price of the extensive use of power electronic devices is becoming clear: increasing harmonic "pollution." The greater amount of harmonics being introduced into power distribution systems is of concern to both power consumers and power companies. First, a brief look is taken at background information which describes harmonic sources, effects, and characteristics. Then the evolution of the harmonics elimination approaches of current compensation and active filtering are discussed to give some insight into the directions that research is taking.
On The Behavior Of The Solutions Of The Navier-Stokes Equations At Vanishing Viscosity, Roger Temam, Xiaoming Wang
On The Behavior Of The Solutions Of The Navier-Stokes Equations At Vanishing Viscosity, Roger Temam, Xiaoming Wang
Mathematics and Statistics Faculty Research & Creative Works
In this article we establish partial results concerning the convergence of the solutions of the Navier-Stokes equations to that of the Euler equations. Namely, we prove convergence on any finite interval of time, in space dimension two, under a physically reasonable assumption. We consider the flow in a channel or the flow in a general bounded domain.
Time Averaged Energy Dissipation Rate For Shear Driven Flows In ℝⁿ, Xiaoming Wang
Time Averaged Energy Dissipation Rate For Shear Driven Flows In ℝⁿ, Xiaoming Wang
Mathematics and Statistics Faculty Research & Creative Works
We drive an upper bound of the time averaged energy dissipation rate for boundary driven flows directly from the Navier-Stokes equations in ℝn. the upper bound is independent of the kinematic viscosity in accordance with Kolomogorov's scaling result. Copyright © 1997 Elsevier Science B.V. All rights reserved.
Disconjugacy And Transformations For Symplectic Systems, Martin Bohner, Ondřej Došlý
Disconjugacy And Transformations For Symplectic Systems, Martin Bohner, Ondřej Došlý
Mathematics and Statistics Faculty Research & Creative Works
We examine transformations and diconjugacy for general symplectic systems which include as special cases linear Hamiltonian difference systems and Sturm-Liouville difference equations of higher order. We give a Reid roundabout theorem for these systems and also for reciprocal symplectic systems. Particularly, we investigate a connection between eventual disconjugacy of linear Hamiltonian difference systems and their reciprocals. Finally, we present a dinsconjugacy-preserving transformation of a Sturm-Liouville equation of higher order which transforms this equation into another one of the same order.
Some Global Bifurcation Results For Variational Inequalities, Vy Khoi Le
Some Global Bifurcation Results For Variational Inequalities, Vy Khoi Le
Mathematics and Statistics Faculty Research & Creative Works
No abstract provided.
Evolutionary Semigroups And Dichotomy Of Linear Skew-Product Flows On Locally Compact Spaces With Banach Fibers, Y. Latushkin, S. Montgomery-Smith, Timothy W. Randolph
Evolutionary Semigroups And Dichotomy Of Linear Skew-Product Flows On Locally Compact Spaces With Banach Fibers, Y. Latushkin, S. Montgomery-Smith, Timothy W. Randolph
Mathematics and Statistics Faculty Research & Creative Works
We study evolutionary semigroups generated by a strongly continuous semi-cocycle over a locally compact metric space acting on Banach fibers. This setting simultaneously covers evolutionary semigroups arising from non-autonomous abstract Cauchy problems and C0-semigroups, and linear skew-product flows. The spectral mapping theorem for these semigroups is proved. The hyperbolicity of the semigroup is related to the exponential dichotomy of the corresponding linear skew-product flow. To this end a Banach algebra of weighted composition operators is studied. The results are applied in the study of: "roughness" of the dichotomy, dichotomy and solutions of nonhomogeneous equations, Green's function for a linear skew-product …
Applications Of The Upside-Down Normal Loss Function, David Drain, A. M. Gough
Applications Of The Upside-Down Normal Loss Function, David Drain, A. M. Gough
Mathematics and Statistics Faculty Research & Creative Works
The upside-down normal loss function (UDNLF) is a weighted loss function that has accurately modeled losses in a product engineering context. The function''s scale parameter can be adjusted to account for the actual percentage of material failing to work at specification limits. Use of the function along with process history allows the prediction of expected loss-the average loss one would expect over a long period of stable process operation. Theory has been developed for the multivariate loss function (MUDNLF), which can be applied to optimize a process with many parameters-a situation in which engineering intuition is often ineffective. Computational formulae …
Asymptotic Analysis Of Oseen Equations For Small Viscosity, R. Temam, X. Wang
Asymptotic Analysis Of Oseen Equations For Small Viscosity, R. Temam, X. Wang
Mathematics and Statistics Faculty Research & Creative Works
In this article, we derive explicit asymptotic formulas for the solutions of Oseen's equations in space dimension two in a channel at large Reynolds number (small viscosity ε). These formulas exhibit typical boundary layers behaviors. Suitable correctors are defined to resolve the boundary obstacle and obtain convergence results valid up to the boundary. We study also the behavior of the boundary layer when simultaneously time and the Reynolds number tend to infinity in which case the boundary layer tends to pervade the whole domain.