• 제목/요약/키워드: solution in closed-form

검색결과 418건 처리시간 0.036초

Structural performance of fiber reinforced cementitious plinths in precast girder bridges

  • Gergess, Antoine N;Challita, Julie
    • Structural Engineering and Mechanics
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    • 제82권3호
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    • pp.313-323
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    • 2022
  • Steel laminated elastomeric bearings are commonly used in bridge structures to control displacements and rotations and transfer forces from the superstructure to the substructure. Proper knowledge of design, fabrication and erection procedures is important to ensure stability and adequate structural performance during the lifetime of the bridge. Difference in elevations sometimes leads to large size gaps between the bearing and the girder which makes the grout thickness that is commonly used for leveling deviate beyond standards. This paper investigates the structural response of High Strength Fiber Reinforced Cementitious (HSFRC) thin plinths that are used to close gaps between bearing pads and precast girders. An experimental program was developed for this purpose where HSFRC plinths of different size were cast and tested under vertical loads that simulate bridge loading in service. The structural performance of the plinths was closely monitored during testing, mainly crack propagation, vertical reaction and displacement. Analytically, the HSFRC plinth was analyzed using the beam on elastic foundation theory as the supporting elastomeric bearing pads are highly compressible. Closed form solutions were derived for induced displacement and forces and comparisons were made between analytical and experimental results. Finally, recommendations were made to facilitate the practical use of HSFRC plinths in bridge construction based on its enhanced load carrying capacity in shear and flexure.

전투시간(戰鬪時間)의 제한성(制限性)을 고려(考慮)한 다수(多數) 대(對) 다수(多數) 전투모형(戰鬪模型) (Stochastic Combats with Time Limitation)

  • 배도선;권태영
    • 대한산업공학회지
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    • 제5권2호
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    • pp.2-7
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    • 1979
  • The fundamental stochastic duel of Williams and Ancker is combined with the probabilistic linear, square and mixed laws of Brown and Smith when the battle time is limited and interfiring times are continuous. The Probability of a given side's winnig or a draw is derived in a recursive equation with Laplace transforms. Examples with negative exponential firing times are given. In linear law an exact closed form solution is obtained, whereas for square and mixed laws only square ($2{\times}2$) duels are considered.

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A CLOSED-FORM SOLUTION FOR TURBULENT WAVE BOUNDARY LAYERS

  • Larson, Magnus
    • 한국해안해양공학회:학술대회논문집
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    • 한국해안해양공학회 1995년도 정기학술강연회 발표논문 초록집
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    • pp.66-70
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    • 1995
  • The oscillatory boundary layer that develops when surface waves propagate over the sea bottom affects many flow-pendent phenomena in the coastal zone. Examples of such phenomena are wave energy dissipation due to bottom friction and the initiation and transport of sediment (Grant and Madsen 1986). In nature the boundary layer under waves will almost always be turbulent (Nielsen 1992). (omitted)

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KHST 차량 벽면의 투과손실값 예측 (Transmission Loss Prediction of KHST's Wall Section)

  • 김관주;윤태중
    • 한국소음진동공학회:학술대회논문집
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    • 한국소음진동공학회 2002년도 추계학술대회논문집
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    • pp.104-109
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    • 2002
  • The purpose of this study is to calculate transmission loss of KHST passenger vehicle's wall section accurately Typical transmission loss measurement of wall in the laboratory condition was carried out in advance, which is easier than KHST. Transmission loss results were compared with those by statistical acoustic method. Transmission loss values of KHST calculated by experimental method are compared with those from closed form solution.

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PROPAGATION OF SURFACE WAVES ON IRREGULAR BED TOPOGRAPHY

  • WARKE A. S.;DAS S. K.;DEBNATH L.
    • Journal of applied mathematics & informatics
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    • 제20권1_2호
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    • pp.197-208
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    • 2006
  • This paper deals with the exact solution of surface gravity waves in an ocean with irregular bed topography. In order to obtain water surface elevation and run-up of infra-gravity waves when the bed is either wavy or exponential, closed form solutions are obtained. Numerical computations indicate that when solitary wave or sinusoidal wave conditions are applied at the boundary, water surface elevation attains near Gaussian profile.

이동로보트의 실시간 위치결정을 위한 수직선과 점 대응 알고리즘 (Fast Algorithm for Location Determination of Mobile Robot: Vertical Line to Point Correspondences)

  • 김재희;조형석
    • 제어로봇시스템학회:학술대회논문집
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    • 제어로봇시스템학회 1990년도 한국자동제어학술회의논문집(국내학술편); KOEX, Seoul; 26-27 Oct. 1990
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    • pp.716-721
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    • 1990
  • It is one of the essential task to determine the absolute location of mobile robot during its navigation. In this paper we propose an algorithm to calculate the distance and orientation of camera from landmark through the visual image of stripe typed landmark. Exact closed form solution of camera location is obtained with the correspondences from vertical line on mark plane to the intersection point of projected line with horizontal axis of image plane. It needs only one line image information, so that location determination can be processed in real time.

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개선된 타부 탐색을 이용한 PID 제어기 설계 (Design of PID Controller using an Improved Tabu Search)

  • 이양우;박경훈;김동욱
    • 대한전기학회논문지:시스템및제어부문D
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    • 제53권5호
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    • pp.323-330
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    • 2004
  • In this paper, we propose a design method of PID controller using an improved Tabu Search. Tabu Search is improved by neighbor solution creation using Gaussian random distribution and generalized Hermite Biehler Theorem for stable bounds. The range of admissible proportional gains are determined first in closed form. Next the optimal PID gains are selected by improved Tabu Search. The results of Computer simulations represent that the proposed Tabu Search algorithm shows a fast convergence speed and a good control performance.

EFFICIENT ESTIMATION OF THE REGULARIZATION PARAMETERS VIA L-CURVE METHOD FOR TOTAL LEAST SQUARES PROBLEMS

  • Lee, Geunseop
    • 대한수학회지
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    • 제54권5호
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    • pp.1557-1571
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    • 2017
  • The L-curve method is a parametric plot of interrelation between the residual norm of the least squares problem and the solution norm. However, the L-curve method may be hard to apply to the total least squares problem due to its no closed form solution of the regularized total least squares problems. Thus the sequence of the solution norm under the fixed regularization parameter and its corresponding residual need to be found with an efficient manner. In this paper, we suggest an efficient algorithm to find the sequence of the solutions and its residual in order to plot the L-curve for the total least squares problems. In the numerical experiments, we present that the proposed algorithm successfully and efficiently plots fairly 'L' like shape for some practical regularized total least squares problems.

ON THE CAUCHY PROBLEM FOR SOME ABSTRACT NONLINEAR DIFFERENTIAL EQUATIONS

  • Hamza A.S. Abujabal;Mahmoud M. El-Boral
    • Journal of applied mathematics & informatics
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    • 제3권2호
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    • pp.279-290
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    • 1996
  • In the present paper we study the Cauchy problem in a Banach space E for an abstract nonlinear differential equation of form $$\frac{d^2u}{dt^2}=-A{\frac{du}{dt}}+B(t)u+f(t, W)$$ where W=($A_1$(t)u, A_2(t)u)..., A_{\nu}(t)u), A_{i}(t),\;i=1,2,...{\nu}$,(B(t), t{\in}I$=[0, b]) are families of closed operators defined on dense sets in E into E, f is a given abstract nonlinear function on $I{\times}E^{\nu}$ into E and -A is a closed linar operator defined on dense set in e into E which generates a semi-group. Further the existence and uniqueness of the solution of the considered Cauchy problem is studied for a wide class of the families ($A_{i}$(t), i =1.2...${\nu}$), (B(t), $t{\in}I$) An application and some properties are also given for the theory of partial diferential equations.

횡등방 압전재료의 면외 계면균열문제 (Antiplane Problem of Interfacial Cracks Bonded with Transversely Isotropic Piezoelectric Media)

  • 최성렬
    • 대한기계학회논문집A
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    • 제36권6호
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    • pp.665-672
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    • 2012
  • 면외 기계적 하중 및 면내 전기적 하중하의 횡등방성 이종 압전재료에 대한 계면균열문제를 해석하였다. 복소함수를 도입하여 문제를 수식화 하고, 이로부터 Hilbert 문제를 구성하였다. Hilbert 문제를 풀므로써, 일반해를 얻었다. 일반해를 사용하여, 반무한 균열 혹은 한 개 유한균열 및 두 개 유한균열에 대한 폐형 해를 각각 구하였다. 이때 하중은 한 개의 집중 기계하중 및 전기적하중이 균열면에 작용한다. 이 문제는 기하조건만 동일하면, 임의의 하중에 대해서도 해를 얻을 수 있는 Green 함수로서 사용될 수 있다.