423 research outputs found
Innovation and Export of Vietnam’s SME Sector
Innovation has long been considered an important factor for creating and maintaining the competitiveness of nations and firms. The relationship between innovation and exporting has been investigated for many countries. However, there is a paucity of research in Vietnam with respect to this issue. In this paper we examine whether innovation performed by Vietnam’s small and medium enterprises (SMEs) enhances their exporting likelihood. Using the recently released Vietnam Small and Medium Enterprise Survey 2005, we find that innovation as measured directly by ‘new products’, ‘new production process’ and ‘improvement of existing products’ are important determinants of exports by Vietnamese SMEs.Vietnam; Export; Innovation; Small and Medium Enterprise
A new stability results for the backward heat equation
In this paper, we regularize the nonlinear inverse time heat problem in the
unbounded region by Fourier method. Some new convergence rates are obtained.
Meanwhile, some quite sharp error estimates between the approximate solution
and exact solution are provided. Especially, the optimal convergence of the
approximate solution at t = 0 is also proved. This work extends to many earlier
results in (f2,f3, hao1,Quan,tau1, tau2, Trong3,x1).Comment: 13 page
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
On a nonlinear heat equation associated with Dirichlet -- Robin conditions
This paper is devoted to the study of a nonlinear heat equation associated
with Dirichlet-Robin conditions. At first, we use the Faedo -- Galerkin and the
compactness method to prove existence and uniqueness results. Next, we consider
the properties of solutions. We obtain that if the initial condition is bounded
then so is the solution and we also get asymptotic behavior of solutions as.
Finally, we give numerical resultsComment: 20 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
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
PRIMARY TEACHERS’ CODE-SWITCHING IN EFL CLASSROOMS
Teaching English has never been easy especially for countries where English is a foreign language. It becomes more challenging if the learners are primary students because their English proficiency is low. Therefore, primary teachers are required to have appropriate teaching methods for them. Code-switching is considered one of teaching methods which is adopted by primary teachers frequently in the classroom. It not only assists teachers in teaching but also in classroom management effectively. Thus, research is conducted to find out functions of CS as well as to the reasons why primary English teachers use it in their classroom. This research is qualitative research. The participants of this study are English teachers who are teaching at primary schools in the Mekong Delta. The instruments of this study were observation, audio-recording, and interview. The results showed that CS was actually used a lot by primary English teachers in their classroom. However, code-switching serve their teaching most. Teachers also admitted that it provided great support for them in teaching such as helping students understand the lesson better and saving time. This study is expected to benefit EFL teachers, especially those who are teaching English for primary schools in general and for young learners in particular. Furthermore, it enables primary EFL teachers to have insights into the functions of CS as well as when it is used in teaching practices. In addition, primary EFL teachers are expected to have critical thinking of the CS and make suitable choices in applying CS effectively.
Article visualizations
Determine the source term of a two-dimensional heat equation
Let be a two-dimensional heat conduction body. We consider the
problem of determining the heat source with
be given inexactly and be unknown. The problem is nonlinear and ill-posed.
By a specific form of Fourier transforms, we shall show that the heat source is
determined uniquely by the minimum boundary condition and the temperature
distribution in at the initial time and at the final time .
Using the methods of Tikhonov's regularization and truncated integration, we
construct the regularized solutions. Numerical part is given.Comment: 18 page
Determination of the body force of a two-dimensional isotropic elastic body
Let represent a twodimensional isotropic elastic body. We
consider the problem of determining the body force whose form
with be given inexactly. The problem is
nonlinear and ill-posed. Using the Fourier transform, the methods of Tikhonov's
regularization and truncated integration, we construct a regularized solution
from the data given inexactly and derive the explicitly error estimate.
Numerical part is givenComment: 23 page
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