• 대한수학회보
• /
• 제50권4호
• /
• pp.1315-1328
• /
• 2013

We first derive several modular equations of degree 5 and present their concise proofs based on algebraic computations. We then establish explicit relations and formulas for some parameterizations for the theta functions ${\varphi}$ and ${\psi}$ by using the derived modular equations. In addition, we find specific values of the parameterizations and evaluate some numerical values of the Rogers-Ramanujan continued fraction.

• 대한수학회보
• /
• 제50권4호
• /
• pp.1221-1233
• /
• 2013

We first derive some modular equations of degrees 3 and 9 and present their concise proofs based on algebraic computations. We then use these modular equations to establish explicit relations and formulas for the parameterizations for the theta functions ${\varphi}$ and ${\psi}$ In addition, we find specific values of the parameterizations to evaluate some numerical values of the cubic continued fraction.

• 한국관개배수논문집
• /
• 제2권1호
• /
• pp.45-56
• /
• 1995

본 연구에서는 미국 West Virgini주 동북부에 위치한 Cheat River Basin 일원에 1985. 11월에 발생한 대홍수를 HEC-1 Computer Model로 재현시켰다. 전체 유역을 수문 및 지형 특성에 따라 각 소유역으로 나누어 각소유역에 대해 지표면유출을 계산하였다. 적용된 단위도는 본 유역의 지형 특성을 고려 Snyder's Unit Hydrograph를 이용하였다. Cheat River 전체에 대한 홍수조절 계획이 본 HEC-1

• 대한수학회지
• /
• 제36권1호
• /
• pp.173-192
• /
• 1999

We study a boundary optimal control problem of the fluid flow governed by the Navier-Stokes equations. the control problem is formulated with the flow through a channel with steps. The first-order optimality condition of the optimal control is derived. Finite element approximations of the solutions of the optimality system are defined and optimal error estimates are derived. finally, we present some numerical results.

• 대한수학회보
• /
• 제50권5호
• /
• pp.1725-1736
• /
• 2013

In this paper, we compute the images of homotopy groups of various classical Lie groups under the homomorphisms induced by the natural projections from those groups to irreducible symmetric spaces of classical type. We identify that those computations are certain lower bounds of Gottlieb groups of irreducible symmetric spaces. We use the lower bounds to compute some Gottlieb groups.

• 대한수학회보
• /
• 제57권2호
• /
• pp.489-508
• /
• 2020

This paper develops an approach to the evaluation of quadratic Euler sums that involve harmonic numbers. The approach is based on simple integral computations of polylogarithms. By using the approach, we establish some relations between quadratic Euler sums and linear sums. Furthermore, we obtain some closed form representations of quadratic sums in terms of zeta values and linear sums. The given representations are new.

• 전력전자학회:학술대회논문집
• /
• 전력전자학회 2004년도 전력전자학술대회 논문집(1)
• /
• pp.54-57
• /
• 2004

In this paper, an optimal design method to have a good performance is researched. The parameters which are senstive to the performance are examined and determined by using evolutionary computations and commercial CAD program to have a good performance. Design method simulated is compared with conventional procedure.

• 대한용접접합학회:학술대회논문집
• /
• 대한용접접합학회 2006년 추계학술발표대회 개요집
• /
• pp.280-282
• /
• 2006

Prediction and control of the thermal distortion is particularly important for the design and manufacture of welded thin plate panel. In this study, experiments and computations are peformed to analyze how hole configuration and the size of the specimen effect on distortion. In addition, this study aims to develop a thermal elasto-plastic simulation using finite element method to predict distortion, with particular emphasis on buckling deformation generated in attachments welded around hole.

• 멤브레인
• /
• 제3권3호
• /
• pp.94-107
• /
• 1993

Many researchers have discussed how membrane performance can be enhanced through an understanding of polymer science and engineering. The understandings of transport in porous membrane are used to achieve the isolation of certain components from mixtures. Particular emphasis is placed on the applicability of membrane separations for the isolation of macromolecules[1]. An awareness of membrane structure characteristics is required for the rational design of membranes for specific and/or new applications. This understanding rests on the knowledge of fields such as polymer thermodynamics[2], polymer adsorption [3, 4], diffusion in polymers[5, 6], reaction mechanism[7], and the dynamic behavior[8, 9] of polymer in porous membrane.

• 제어로봇시스템학회:학술대회논문집
• /
• 제어로봇시스템학회 1993년도 한국자동제어학술회의논문집(국내학술편); Seoul National University, Seoul; 20-22 Oct. 1993
• /
• pp.947-952
• /
• 1993

A simplified pole-placement design method is developed by analysing dynamic characteristics of the switching dynamics. Unlike the design procedure of conventional pole-placement, in the proposed method, overall state-space is directly decomposed into two invariant subspaces by the projection operator which is defined in the equivalent system, and then the closed-loop poles are assigned to each subspace independently. Hence, computations for state-feedback gain matrix are easy and simple.