• 한국도서관정보학회지
• /
• 제44권3호
• /
• pp.5-27
• /
• 2013

이 연구의 목적은 미국의 '한 책, 한 도시' 지역사회 독서운동 확산의 시기적 특성 및 지속성에 관하여 살펴보는 것이다. 2013년 6월까지 미국의회도서관 도서센터 웹사이트에 등록된 584개 '한 책' 프로젝트들의 확산 현황 및 특성을 태동기 (1998년-2001년), 성장기 (2002년-2006년) 및 재도약기 (2007년-현재)의 세 시기로 나누어 살펴보았다. 또한 주요한 '한 책' 프로젝트들의 웹사이트 등을 분석하여 적어도 50개(8.9%) 이상 '한 책' 프로젝트들의 지속성, 특히 초기에 시작된 '한 책' 프로젝트들의 안정성을 확인하였다. 지속적인 일부 '한 책' 프로젝트의 새로운 변화 모색 및 'The Big Read' 이니셔티브를 통한 '한 책' 독서운동 모형의 확산 추이는 향후 주목할 만하다.

• 전기학회논문지
• /
• 제62권10호
• /
• pp.1354-1360
• /
• 2013

In transmission system, reclosing scheme is very useful method to improve continuity of power supply and reliability of system. Especially, high speed reclosing which is used generally in transmission systems has a benefit improving transient stability. However, the reclosing can jeopardize the stability under the condition having high difference of voltage phase angle between both ends. Thus, this paper proposes optimal sequential reclosing scheme to improve transient stability due to reclosing operation. The optimal sequential reclosing is that each phase is closed sequentially considering transient energy. In this paper, 345kV and 154kV transmission system is modeled using EMTP (ElectroMagnetic Transient Program) to verify the performance and effectiveness of optimal sequential reclosing on transient stability. Also, Integral Square Error(ISE) method is used to assess the transient stability.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1996년도 춘계 학술대회논문집
• /
• pp.46-51
• /
• 1996

The flow field around a three dimensional minivan-like body has been simulated. This study solves 3-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system using second-order accurate schemes for the time derivatives, and third/second-order scheme for the spatial derivatives. The Marker-and-Cell concept is applied to efficiently solve continuity equation. The fourth -order artificial damping is added to the continuity equation for numerical stability. A H-H type multi-block grid system is generated around a three dimensional minivan-like body. Turbulent flows have been modeled by the Baldwin-Lomax turbulent model. The simulation shows three dimensional vortex-pair just behind body. And the flow separation is also observed the rear of the body. It has concluded that the results of present study properly agree with physical flow phenomena.

• 한국전산유체공학회:학술대회논문집
• /
• 한국전산유체공학회 1997년도 추계 학술대회논문집
• /
• pp.86-91
• /
• 1997

This paper describes analysis of complex flow around Car-like body using Chimera grid technique. As a computational algorithm, Pullboat and Chaussee's Diagonal algorithm is selected to reduce computational time. Introducing hole points flag to this Diagonal algorithm, an algorithm for Chimera grid is generated easily. This study solves 3-D unsteady incompressible Navier-Stokes equations on a non-orthogonal curvilinear coordinate system using second-order accurate schemes for the time derivatives, and third/second-order scheme for the spatial derivatives. The Marker-and-Cell concept is applied to efficiently solve continuity equation. The fourth-order artificial damping is added to the continuity equation for numerical stability, It has concluded that the results of present study properly agree with physical flow phenomena.

• Nonlinear Functional Analysis and Applications
• /
• 제26권4호
• /
• pp.749-780
• /
• 2021

In this paper, we give the notion of M(., .)-𝜂-proximal mapping for a nonconvex, proper, lower semicontinuous and subdifferentiable functional on Banach space and prove its existence and Lipschitz continuity. As an application, we introduce and investigate a new system of variational-like inclusions in Banach spaces. By means of M(., .)-𝜂-proximal mapping method, we give the existence of solution for the system of variational inclusions. Further, propose an iterative algorithm for finding the approximate solution of this class of variational inclusions. Furthermore, we discuss the convergence and stability analysis of the iterative algorithm. The results presented in this paper may be further expolited to solve some more important classes of problems in this direction.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 2000년도 춘계학술대회논문집
• /
• pp.695-700
• /
• 2000

The dynamic stability of spinning beam with free boundary conditions for both edges subjected to a tip follower force $P_0+P_1cos{\Omega}t$ is analyzed. It is studied that the beam has a concentrated mass. and then the effects of the axial locations of the mass are studied. The beam is modelled with the Timoshenko type shear deformations. The Hamilton's principle is used to derive the equations of motion, and the critical spinning speed of a beam subjected to a follower force with various non-dimensional parameters is investigated. The finite elements are used with $C^0$ continuity to analyze the spinning beam model, and the method of multiple scales is tried to investigate the dynamic instability regions. The governing equations of motion involve periodic coefficients, which are not in the form of standard Mathieu-Hill equations. The result shows that the concentrated mass increases the dynamic stability of the spinning free-free beam subjected to a thrust.

• Structural Engineering and Mechanics
• /
• 제6권6호
• /
• pp.711-725
• /
• 1998

Mixed finite element formulations for incompressible materials show pressure oscillations or pressure modes in four-node quadrilateral elements. The criterion for the stability in the pressure solution is the so-called Babu$\check{s}$ka-Brezzi stability condition, and the four-node elements based on mixed variational principles do not appear to satisfy this condition. In this study, a pressure continuity residual based on the pressure discontinuity at element edges proposed by Hughes and Franca is used to study the stabilization of pressure solutions in bilinear displacement-constant pressure four-node quadrilateral elements. Also, a solid mechanics problem is presented by which the stability of mixed elements can be studied. It is shown that the pressure solutions, although stable, are shown to exhibit sensitivity to the stabilization parameters.

• 대한기계학회논문집
• /
• 제15권6호
• /
• pp.1861-1871
• /
• 1991

본 연구에서는 아직까지 연구가 미진한 내용 즉, 유속과 압력이 시간과 위치 의 함수인 유동특성과 파이프의 운동이 상호 연계되어 영향을 주는 일반적인 경우의 운동방정식을 유도하였고 단순지지된 직선 파이프를 모델로 설정하여 동적 안정성 (dynamic stability)과 진동응답을 수치적으로 고찰하였다.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제26권1호
• /
• pp.35-47
• /
• 2019

The purpose of this paper is to introduce and study new notions of continuity, compactness and stability in ditopological texture spaces based on the notions of ${\beta}$-g-open and ${\beta}$-g-closed sets and some of their characterizations are obtained. Finally, the relationships between these concepts and the other related concepts are investigated.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 1996년도 창립기념 전력전자학술발표회 논문집
• /
• pp.5-12
• /
• 1996

In this paper, we design a Continuous Variable Structure Controller which can control robot manipulators to follow the desired planned trajectory with accuracy and robustness, and improve continuity and robustness of variable structure control, based on disturbance observer. We also analyze the stability the proposed algorithm and then verify the usefulness and performance through simulation stuies.