• 제목/요약/키워드: infinite case

검색결과 312건 처리시간 0.027초

중규모 사무공간에서 조명에너지 성능평가를 위한 노모그래프 개발에 관한 연구 (Development of Nomographs for the Evaluation of Lighting Energy Performance in a Semi-infinite Office Space)

  • 김한성;고동환;김강수
    • 한국태양에너지학회 논문집
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    • 제23권3호
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    • pp.73-80
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    • 2003
  • The purpose of this study was to analyze daylighting performance in a semi-infinite size office space for lighting energy conservation. DOE2.1E was used for simulations for the model space of $12\times12\times2.6m$. Nomographs were developed which could simulate work plane illuminance, glare index, energy consumption rate and energy reduction rate for daylighting design. Major results of simulations are as follows ; 1) When blinds facing south were installed, 43% of workplane illuminance diminished, but the flare index didn't exceed the recommended max-glare value. 2) In a semi-infinite office space facing south. energy consumption rate in the case space of 500 lux workplane illuminance is larger then case space of 300 lux workplane illuminance. Therefore, energy reduction rate is increased when the semi-infinite office faces south and naintains 300 lux workplane illuminance level.

KAZDAN-WARNER EQUATION ON INFINITE GRAPHS

  • Ge, Huabin;Jiang, Wenfeng
    • 대한수학회지
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    • 제55권5호
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    • pp.1091-1101
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    • 2018
  • We concern in this paper the graph Kazdan-Warner equation $${\Delta}f=g-he^f$$ on an infinite graph, the prototype of which comes from the smooth Kazdan-Warner equation on an open manifold. Different from the variational methods often used in the finite graph case, we use a heat flow method to study the graph Kazdan-Warner equation. We prove the existence of a solution to the graph Kazdan-Warner equation under the assumption that $h{\leq}0$ and some other integrability conditions or constrictions about the underlying infinite graphs.

제한공간에서 비예혼합 난류제트 화염의 부상특성 (Characteristics of Lifted Flames in Nonpremixed Turbulent Confined Jets)

  • 차민석;정석호
    • 한국연소학회지
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    • 제1권1호
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    • pp.41-49
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    • 1996
  • Effects of ambient geometry on the liftoff characteristics are experimentally studied for nonpremixed turbulent jet flames. To clarify the inconsistency of the nozzle diameter effect on the liftoff height, the ambiences of finite and infinite domains are studied. For nonpremixed turbulent jet issuing from a straight nozzle to infinite domain, flame liftoff height increases linearly with nozzle exit mean velocity and is independent of nozzle diameter. With the circular plate installed on the upstream of nozzle exit, flame liftoff height is lower with plate at jet exit than without, but flame liftoff characteristics are similar to the case of infinite domain. For the confined jet having axisymmetric wall boundary, the ratio of the liftoff height and nozzle diameter is proportional to the nozzle exit mean velocity demonstrating the effect of the nozzle diameter on the liftoff height. The liftoff height increases with decreasing outer axisymmetric wall diameter. At blowout conditions, the blowout velocity decreases with decreasing outer axisymmetric wall diameter and liftoff heights at blowout are approximately 50 times of nozzle diameter.

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반무한체에 접합된 두 등방성 층의 좌굴 해석 (Buckling Analysis of Two Isotropic Layers Bonded to a Semi-Infinite Substrate)

  • 정경문;범현규
    • 대한기계학회논문집A
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    • 제24권8호
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    • pp.2108-2114
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    • 2000
  • The buckling of two elastic layers bonded to a semi-infinite substrate under a transverse compressive plane strain is investigated. Incremental deformation theory, which considers the effect of the initial stress on the incremental stress field, is employed to describe the buckling behavior of both two isotropic layers and the semi-infinite substrate. The problem is converted to an eigenvalue-eigenvector case, from which the critical buckling strain and the buckling wavelength are obtained. The results are presented on the effects of the layer geometries and material properties on the buckling behavior.

해양구조물의 파력산정을 위한 3-차원 무한요소 (THREE-DIMENSIONAL INFINITE ELEMENTS FOR WAVE FORCE EVALUATION ON OFFSHORE STRUCTURES)

  • Park, Woo-Sun;Yoon, Chung-Bang;Pyun, Chong-Kun
    • 한국전산구조공학회:학술대회논문집
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    • 한국전산구조공학회 1991년도 봄 학술발표회 논문집
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    • pp.8-14
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    • 1991
  • The finite element technique incorporating infinite elements is applied to analyzing the general three dimensional wave-structure interaction problems within the limits of linear wave theory. The hydrodynamic farces are assumed to be inertially dominated, and viscous effects are neglected. In order to analyze the corresponding boundary value problems efficiently, two types of elements are developed. One is the infinite element for modeling the radiation condition at infinity, and the other is the fictitious bottom boundary element for the case of deep water. To validate those elements, numerical analyses are performed for several floating structures. Comparisons with the results from culler available solution methods show that the present method incorporating tile infinite and the fictitious bottom boundary elements gives good results.

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증분 변형 이론을 이용한 반무한체에 접합된 두 탄성층의 좌굴 해석 (Buckling Analysis of Two Elastic Layers Bonded to a Semi-Infinite Substrate Using Incremental Deformation Theory)

  • 정경문;범현규
    • 대한기계학회:학술대회논문집
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    • 대한기계학회 2000년도 춘계학술대회논문집A
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    • pp.369-374
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    • 2000
  • The buckling of two elastic layers bonded to a semi-infinite substrate under a transverse compressive plane strain is investigated. Incremental deformation theory is employed to describe the buckling behavior of both two isotropic layers and the semi-infinite substrate. The problem is converted to an eigenvalue-eigenvector case, from which the critical buckling strain and the wavelength of the buckled shape are obtained. The results are presented on the effects of the layer geometries and material properties on the buckling behavior.

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FINITE ELEMENT METHOD FOR SOLVING BOUNDARY CONTROL PROBLEM GOVERNED BY ELLIPTIC VARIATIONAL INEQUALITIES WITH AN INFINITE NUMBER OF VARIABLES

  • Ghada Ebrahim Mostafa
    • Nonlinear Functional Analysis and Applications
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    • 제28권3호
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    • pp.613-622
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    • 2023
  • In this paper, finite element method is applied to solve boundary control problem governed by elliptic variational inequality with an infinite number of variables. First, we introduce some important features of the finite element method, boundary control problem governed by elliptic variational inequalities with an infinite number of variables in the case of the control and observation are on the boundary is introduced. We prove the existence of the solution by using the augmented Lagrangian multipliers method. A triangular type finite element method is used.

Hydrodynamic forces on blocks and vertical wall on a step bottom

  • Mondal, Ramnarayan;Alam, Md. Mahbub
    • Wind and Structures
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    • 제30권5호
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    • pp.485-497
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    • 2020
  • A study, using potential water wave theory, is conducted on the oblique water wave motion over two fixed submerged rectangular blocks (breakwaters) placed over a finite step bottom. We have considered infinite and semi-infinite fluid domains. In both domains, the Fourier expansion method is employed to obtain the velocity potentials explicitly in terms of the infinite Fourier series. The unknown coefficients appearing in the velocity potentials are determined by the eigenfunction expansion matching method at the interfaces. The derived velocity potentials are used to compute the hydrodynamic horizontal and vertical forces acting on the submerged blocks for different values of block thickness, gap spacing between the two blocks, and submergence depth of the upper block from the mean free surface. In addition, the wave load on the vertical wall is computed in the case of the semi-infinite fluid domain for different values of blocks width and the incident wave angle. It is observed that the amplitudes of hydrodynamic forces are negligible for larger values of the wavenumber. Furthermore, the upper block experiences a higher hydrodynamic force than the lower block, regardless of the gap spacing, submergence depth, and block thickness.

무한차원 시스템을 위한 선형 이차상태 궤한 제어기의 견인성에 관한 연구 (On Robustness of Linear Quadratic State Feedback Regulators for Infinite Dimensional systems)

  • Seo, Jin-Heon
    • 대한전기학회논문지
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    • 제37권7호
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    • pp.490-497
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    • 1988
  • This paper is concerned with the robust stability of linear quadratic state feedback regulators for infinite dimensional systems in the presence of system uncertainties Several robustness results ensuring the asymptoitc stability and exponential stability of the perturbed closed loop system are derived for a class of nonlinear perturbations of the system and input operators satisfying the matching condition. For the case where the input space is finite dimensional, some robust properties of the state feedback regulator designed on the basis of the linear quadratic regulator for finite dimensional unstable modes are also discussed seperately.

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HEAT EQUATION IN WHITE NOISE ANALYSIS

  • KimLee, Jung-Soon
    • 대한수학회지
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    • 제33권3호
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    • pp.541-555
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    • 1996
  • The Fourier transform plays a central role in the theory of distribution on Euclidean spaces. Although Lebesgue measure does not exist in infinite dimensional spaces, the Fourier transform can be introduced in the space $(S)^*$ of generalized white noise functionals. This has been done in the series of paper by H.-H. Kuo [1, 2, 3], [4] and [5]. The Fourier transform $F$ has many properties similar to the finite dimensional case; e.g., the Fourier transform carries coordinate differentiation into multiplication and vice versa. It plays an essential role in the theory of differential equations in infinite dimensional spaces.

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