박재민 교수

The increase in population and urbanization needs attention towards intense construction activities to meet the social and economic needs. Soil excavation is a primary step in every construction project that needs proper surface and subsurface information modeling since it is vulnerable to construction hazards. Geographic information system (GIS) provides significant information about the existing contextual surface information while building information modeling (BIM) gives information about th

We study the radial symmetry properties of stationary and uniformly rotating solutions of the 2D Euler and gSQG equations, both in the smooth setting and the patch setting. For the 2D Euler equation, we show that any smooth stationary solution with compactly supported and nonnegative vorticity must be radial, without any assumptions on the connectedness of the support or the level sets. For the 2D Euler equation in the patch setting, we show that every uniformly rotating patch D with angular vel

In this paper, we study the radial symmetry properties of stationary and uniformly-rotating solutions of the 2D Euler and gSQG equations, both in the smooth setting and the patch setting. For the 2D Euler equation, we show that any smooth stationary solution with compactly supported and nonnegative vorticity must be radial, without any assumptions on the connectedness of the support or the level sets. In the patch setting, for the 2D Euler equation we show that every uniformly-rotating patch $D$

Abstract In this paper, we show that the only solution of the vortex sheet equation, either stationary or uniformly rotating with negative angular velocity $$\Omega $$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mi>Ω</mml:mi> </mml:math> , such that it has positive vorticity and is concentrated in a finite disjoint union of smooth curves with finite length is the trivial one: constant vorticity amplitude supported on a union of nested, concentric circles. The proof follows a d

Microgrids are fundamental elements in modern energy systems. Among the various microgrid components, the Energy Storage System (ESS) plays a pivotal role in ensuring system reliability, but its high cost and inevitable degradation over time pose significant challenges. Many current studies overlook the impact of ESS degradation on operational optimization, potentially leading to cost-ineffective systems. To address this gap, we introduce a quadratic ESS degradation model that captures intricate

In this paper, we construct new, uniformly rotating solutions of the vortex sheet equation bifurcating from circles with constant vorticity amplitude. The proof is accomplished via a Lyapunov-Schmidt reduction and a second-order expansion of the reduced system. This article is part of the theme issue 'Mathematical problems in physical fluid dynamics (part 2)'.

A clinical practice guideline for patients in the dying process in general wards and their families, developed through an evidence-based process, is presented herein. The purpose of this guideline is to enable a peaceful death based on an understanding of suitable management of patients’ physical and mental symptoms, psychological support, appropriate decision- making, family care, and clearly-defined team roles. Although there are limits to the available evidence regarding medical issues in pat

본 연구는 김대중정부의 햇볕정책이 일방적인 퍼주기인지, 아니면 남한정부의 주장대로 남한이 우호적인 행위를 하고 북한으로부터 그에 상응하는 우호적 행위를 돌려 받았는지를 평가하고 있다. 남한은 북한에 대해 우호적인 정책을 가지고 북한에 우호적인 행위를 하였으나, 북한은 남한의 우호적 행위를 우호적 행위라고 인식하지 않거나 우호적 행위의 동기가 불순하다는 생각에서 우호적 행위를 하지 않은 경우가 발견된다. 또한 북한은 체제유지상 남한에 우호적 행위를 할 여력이 없었다. 그런 중에도 북한은 남한의 우호적 행위로 인해 많은 이득을 얻었다는 것을 인정하고 정상회담과 이산가족문제 등에서 남한이 원하는 우호적 행위를 보여주었다.

The purpose of this study was to figure out consumer's recognition on brand's peculiar style on Korean contemporary women's apparel brand. The contemporary women's apparel brands show advanced and stylish merchandise at better price points. This segment of the Korean ready-to-wear market has been growing fast in last decades. Four contemporary women's apparel brands(I, K, M, and T) were participated in this study. The data(n=216) were collected with questionnaire survey at 24 apparel retail shop

In this paper, we derive some quantitative estimates for uniformly-rotating vortex patches. We prove that if a non-radial simply-connected patch D is uniformly-rotating with small angular velocity 0<Ω≪1, then the outmost point of the patch must be far from the center of rotation, with distance at least of order Ω−1/2. For m-fold symmetric simply-connected rotating patches, we show that their angular velocity must be close to 12 for m≫1 with the difference at most O(1/m), and also obtain estimate

In this paper, we revisit asymptotic stability for the two-dimensional incompressible porous media equation and the Stokes transport system in a periodic channel. It is well-known that a stratified density, which strictly decreases in the vertical direction, is asymptotically stable under sufficiently small and smooth perturbations. We provide improvements in the regularity assumptions on the perturbation and in the convergence rate. Unlike the standard approach for stability analysis relying on

In this study, we propose an optimal strategy for managing multiple energy storage systems (ESS) to reduce both electricity expenses and battery degradation costs. Our approach uses a two-stage optimization process for battery management. In the first stage, reinforcement learning (RL) identifies the aggregated optimal amounts for charging and discharging. Then, quadratic programming (QP) distributes these aggregated amounts across multiple batteries. Experiments conducted under different test c

In this paper, we construct an example of temperature patch solutions for the two-dimensional, incompressible Boussinesq system with kinematic viscosity such that both the curvature and perimeter grow to infinity over time. The presented example consists of two disjoint, simply connected patches. The rates of growth for both curvature and perimeter in this example are at least algebraic.