594 research outputs found
Existence and Decay of Solutions of a Nonlinear Viscoelastic Problem with a Mixed Nonhomogeneous Condition
We study the initial-boundary value problem for a nonlinear wave equation
given by u_{tt}-u_{xx}+\int_{0}^{t}k(t-s)u_{xx}(s)ds+ u_{t}^{q-2}u_{t}=f(x,t,u)
, 0 < x < 1, 0 < t < T, u_{x}(0,t)=u(0,t), u_{x}(1,t)+\eta u(1,t)=g(t),
u(x,0)=\^u_{0}(x), u_{t}(x,0)={\^u}_{1}(x), where \eta \geq 0, q\geq 2 are
given constants {\^u}_{0}, {\^u}_{1}, g, k, f are given functions. In part I
under a certain local Lipschitzian condition on f, a global existence and
uniqueness theorem is proved. The proof is based on the paper [10] associated
to a contraction mapping theorem and standard arguments of density. In Part} 2,
under more restrictive conditions it is proved that the solution u(t) and its
derivative u_{x}(t) decay exponentially to 0 as t tends to infinity.Comment: 26 page
The regularity and exponential decay of solution for a linear wave equation associated with two-point boundary conditions
This paper is concerned with the existence and the regularity of global
solutions to the linear wave equation associated with two-point type boundary
conditions. We also investigate the decay properties of the global solutions to
this problem by the construction of a suitable Lyapunov functional.Comment: 18 page
Existence, blow-up and exponential decay estimates for a nonlinear wave equation with boundary conditions of two-point type
This paper is devoted to study a nonlinear wave equation with boundary
conditions of two-point type. First, we state two local existence theorems and
under suitable conditions, we prove that any weak solutions with negative
initial energy will blow up in finite time. Next, we give a sufficient
condition to guarantee the global existence and exponential decay of weak
solutions. Finally, we present numerical resultsComment: 2
Characterization of O-glycan binding lectin from the red alga Hydropuntia eucheumatoides
The red alga, Hydropuntia eucheumatoides is one of the algal genera from which agar is commercially extracted, and is the main source of agar in the world. The lectin HEL from the red alga H. eucheumatoides was isolated by a combination of aqueous ethanol extraction, ethanol precipitation, ion exchange and filtration chromatography. Lectin gave a single band with molecular mass of 17,000 Da in both non-reducing and reducing SDS-PAGE conditions, therefore lectin exists in monomeric form. The hemagglutination activities of HEL were stable over a wide range of pH from 3 to 10, temperature up 60 oC and not affected by either the presence of EDTA or addition of divalent cations, indicating that lectin requires no metal for biological activity. The hemagglutination activities of HEL were not inhibited by monosaccharides and glycoproteins, D-glucose, D-mannose, D-galactose, D-xylose, N-acety-D-mannosamine, transferin, fetuin and yeast mannan, but strongly inhibited by monosaccharides containing acetamido groups at equatorial C2 position, such as N-acetyl-galactosamine, N-acetyl-glucosamine, N-acetyl-neuraminic acid and glycoprotein porcine stomach mucin bearing O-glycans. Thus, lectin is specific for O-glycans and may recognize the sequences GalNAcαSer/Thr, GalNAc(α1-3)[Fuc(α1-2)]Gal(β1-4)GlcNAc(β1-3)GalNAc- and GluNAc(α1-4)Gal- under interacting with the acetamido groups at equatorial C2 position of the terminal sugar residues in oligosaccharide structures of O-glycans. The red alga H. eucheumatoides could promise to be a source of valuable lectins for application in biochemistry and biomedicine
Large time behavior of differential equations with drifted periodic coefficients modeling Carbon storage in soil
This paper is concerned with the linear ODE in the form
, which represents a simplified
storage model of the carbon in the soil. In the first part, we show that, for a
periodic function , a linear drift in the coefficient involves
a linear drift for the solution of this ODE. In the second part, we extend the
previous results to a classical heat non-homogeneous equation. The connection
with an analytic semi-group associated to the ODE equation is considered in the
third part. Numerical examples are given.Comment: 18 page
FACTORS AFFECTING CAN THO RESIDENTS’ INTENTION TO VISIT DALAT IN THE COVID-19 ERA
The paper examines the factors affecting the intentions of Can Tho residents to travel to Dalat as the COVID-19 pandemic is gradually brought under control. The data were collected from a survey of 213 Can Tho residents and analyzed with Cronbach’s alpha, exploratory factor analysis, confirmatory factor analysis, and structural equation modeling. The results show that the intentions of Can Tho residents to travel to Dalat depend on four factors: (1) attitude toward Dalat tourism, (2) subjective norms, (3) perceived behavioral controls, and (4) perceived health risk. In particular, the attitudinal factor significantly influences Dalat travel intentions. Based on the research results, the article proposes four recommendations for managers, corresponding to the four influencing factors, to increase the intentions of Can Tho residents to travel to Dalat in the COVID-19 era
Exploiting No-Regret Algorithms in System Design
We investigate a repeated two-player zero-sum game setting where the column
player is also a designer of the system, and has full control on the design of
the payoff matrix. In addition, the row player uses a no-regret algorithm to
efficiently learn how to adapt their strategy to the column player's behaviour
over time in order to achieve good total payoff. The goal of the column player
is to guide her opponent to pick a mixed strategy which is favourable for the
system designer. Therefore, she needs to: (i) design an appropriate payoff
matrix whose unique minimax solution contains the desired mixed strategy of
the row player; and (ii) strategically interact with the row player during a
sequence of plays in order to guide her opponent to converge to that desired
behaviour. To design such a payoff matrix, we propose a novel solution that
provably has a unique minimax solution with the desired behaviour. We also
investigate a relaxation of this problem where uniqueness is not required, but
all the minimax solutions have the same mixed strategy for the row player.
Finally, we propose a new game playing algorithm for the system designer and
prove that it can guide the row player, who may play a \emph{stable} no-regret
algorithm, to converge to a minimax solution
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