Kyeong-Hun Kim

Let $p(t,x)$ be the fundamental solution to the problem $$ \partial_{t}^αu=-(-Δ)^βu, \quad α\in (0,2), \, β\in (0,\infty). $$ In this paper we provide the asymptotic behaviors and sharp upper bounds of $p(t,x)$ and its space and time fractional derivatives $$ D_{x}^{n}(-Δ_x)^γD_{t}^σI_{t}^δp(t,x), \quad \forall\,\, n\in\mathbb{Z}_{+}, \,\, γ\in[0,β],\,\, σ, δ\in[0,\infty), $$ where $D_{x}^n$ is a partial derivative of order $n$ with respect to $x$, $(-Δ_x)^γ$ is a fractional Laplace operator and

In this paper we develop a Fefferman-Stein theorem, a Hardy-Littlewood theorem and sharp function estimations in weighted Sobolev spaces. We also provide uniqueness and existence results for second-order elliptic and parabolic partial differential systems in weighed Sobolev spaces.

Stochastic partial differential equations with variable coefficients are considered in C1 domains. Existence and uniqueness results are given in Sobolev spaces with weights allowing the derivatives of the solutions to blow up near the boundary. The number of derivatives of the solution can be negative and fractional, and the coefficients of the equations are allowed to substantially oscillate or blow up near the boundary.

In this paper we give an $L_p$-theory for stochastic parabolic equations with random fractional Laplacian operator. The driving noises are general Lévy processes.

Second-order parabolic equations with variable coecientsare considered on Rd and C¹ domains. Existence and uniqueness resultsare given in Lq(Lp)-spaces, where it is allowed for the powers of summa-bility with respect to space and time variables to be dierent.

The development and design of metal materials have been carried out through experimental method and simulation based on theoretic. Recently, with the widespread application of artificial intelligence (AI) in various fields, many studies have been actively incorporating artificial intelligence into the field of metal material design. Especially, many studies have been reported on adding rare-earth elements to aluminum alloys to improve corrosion resistance and mechanical properties using AI. Howe

We deal with the Sobolev space theory for the stochastic partial differential equation (SPDE) driven by Wiener processes $$ \partial_{t}^αu=\left( ϕ(Δ) u +f(u) \right) + \partial_t^β\sum_{k=1}^\infty \int_0^t g^k(u)\,dw_s^k, \quad t>0, x\in \mathbb{R}^d; \,\,\, u(0,\cdot)=u_0 $$ as well as the SPDE driven by space-time white noise $$ \partial^α_{t}u=ϕ(Δ)u + f(u) + \partial^{β-1}_{t}h(u) \dot{W}, \quad t>0,x\in \mathbb{R}^d; \quad u(0,\cdot)=u_{0}. $$ Here, $α\in (0,1), β\in (-\infty, α+1/2

In this article we present a $W^n_2$-theory of stochastic parabolic partial differential systems. In particular, we focus on non-divergent type. The space domains we consider are $\bR^d$, $\bR^d_+$ and eventually general bounded $C^1$-domains $\mathcal{O}$. By the nature of stochastic parabolic equations we need weighted Sobolev spaces to prove the existence and the uniqueness. In our choice of spaces we allow the derivatives of the solution to blow up near the boundary and moreover the coeffici

In this paper we present a weighted $L_p$-theory of second-order parabolic partial differential equations defined on $C^1$ domains. The leading coefficients are assumed to be measurable in time variable and have VMO (vanishing mean oscillation) or small BMO (bounded mean oscillation) with respect to space variables, and lower order coefficients are allowed to be unbounded and to blow up near the boundary. Our BMO condition is slightly relaxed than the others in the literature.