• 제목/요약/키워드: analytical models

검색결과 1,511건 처리시간 0.026초

비선형 곤충 온도발육모형의 특성과 발전과정에 대한 고찰 (A Review for Non-linear Models Describing Temperature-dependent Development of Insect Populations: Characteristics and Developmental Process of Models)

  • 김동순;안정준;이준호
    • 한국응용곤충학회지
    • /
    • 제56권1호
    • /
    • pp.1-18
    • /
    • 2017
  • 곤충의 온도발육모형은 해충의 발생예찰모형을 비롯한 개체군모형에서 기본이 되는 요소이다. 본고에서는 곤충의 온도의존적 비선형 발육모형에 대하여 고찰하였다. 모형의 종류를 크게 경험모형과 생물리적 모형으로 구분하였으며, 수식의 유사성 내지 기원에 대한 유연관계에 따라 세분하였다. 발육률 곡선의 형태적 묘사에 적합한 수식을 적용하는 경험모형은 Stinner-계열, Logan-계열, 수행모형, 그리고 베타 분포모형으로 세분화하여 고찰하였다. 촉매반응을 바탕으로 하고 있는 생물리적 모형은 Eyring-모형, SM-모형, SS-모형, SSI-모형으로 이어지는 단계통으로 분류하였다. 본 연구에 포함된 각 모형의 개발과정과 형태적합 특성에 대하여 기술하였다.

Analysis of composite plates using various plate theories -Part 2: Finite element model and numerical results

  • Bose, P.;Reddy, J.N.
    • Structural Engineering and Mechanics
    • /
    • 제6권7호
    • /
    • pp.727-746
    • /
    • 1998
  • Finite element models and numerical results are presented for bending and natural vibration using the unified third-order plate theory developed in Part 1 of this paper. The unified third-order theory contains the classical, first-order, and other third-order plate theories as special cases. Analytical solutions are developed using the Navier and L$\acute{e}$vy solution procedures (see Part 1 of the paper). Displacement finite element models of the unified third-order theory are developed herein. The finite element models are based on $C^0$ interpolation of the inplane displacements and rotation functions and $C^1$ interpolation of the transverse deflection. Numerical results of bending and natural vibration are presented to evaluate the accuracy of various plate theories.

국내 철골골조의 접합부모델에 따른 내진성능 비교 (Comparison of Seismic Performance of Steel Moment Frame according to Different Analytic Joint Models)

  • 이준석;한상환;이리형
    • 한국전산구조공학회:학술대회논문집
    • /
    • 한국전산구조공학회 2000년도 봄 학술발표회논문집
    • /
    • pp.317-323
    • /
    • 2000
  • The purpose of this study is to compare the seismic resistant capacity inherent in ductile moment resisting frames using two different joint modeling. The difference between these two models is the capability for considering the panel zone deformation. For this purpose, 5 story steel moment frame is designed in compliance to the Korean seismic design provisions and the steel structure design standard. Nonlinear Static Procedure(NSP) and Nonlinear Dynamic Procedure(NDP) of this structure are carried out using two different joint models. Based on the results of NSP and NDP, the sensitivity of the response to analytical modeling is appraised. Also, it is proposed that for the highrise steel structures, the joint deformation should be accounted properly by the analytical model.

  • PDF

보강근과 콘크리트 사이의 해석적 부착모델 비교 (Comparison of Analytical Bond Models between Reinforcement and Concrete)

  • 유영준;박지선;박영환;김형열;유영찬;김긍환
    • 한국콘크리트학회:학술대회논문집
    • /
    • 한국콘크리트학회 2005년도 추계 학술발표회 제17권2호
    • /
    • pp.33-36
    • /
    • 2005
  • This paper presents the comparison of the goodness-of-fit test of analytical bond models between concrete and steel or GFRP reinforcements. Bond test specimens were made by the CSA code and the rebars used in the test were steel and two kinds of GFRP rebar commercially utilized. The comparison of goodness-of-fit test for existing bond models and new proposed bond model was carried out by the least squares method. The result indicates that the new proposed bond model has better goodness-of-fit test than the existing ones.

  • PDF

능동구속층 감쇠를 이용한 판의 동역학적 해석 (Dynamic Analysis of Plates with Active Constrained Layer Damping)

  • 박철휴
    • 한국소음진동공학회:학술대회논문집
    • /
    • 한국소음진동공학회 2004년도 춘계학술대회논문집
    • /
    • pp.581-586
    • /
    • 2004
  • This paper presents Newtonian formulation of the dynamics of plates treated fully with Active Constrained Layer Damping (ACLD). The developed equations of the plate/ACLD system provide analytical models far predicting the dynamic of laminated plates subjected to passive and active vibration damping controls. Numerical solutions of the analytical models are presented fir simply-supported plates in order to study the performance of the plate/ACLD system for different control strategies. The developed models present invaluable means for designing and predicting the performance of the smart laminated plates that can be used in many critical engineering applications.

  • PDF

수직축(垂直軸) Darrieus 풍력(風力) 터어빈의 공기역학적특성(空氣力學的特性) 해석(解析)에 관한 연구(硏究) (A Study on the Analytical Methods for the Aerodynamic Characteristics of Vertical-Axis Darrieus Wind Turbine)

  • 김건훈;이철형;이규현
    • 태양에너지
    • /
    • 제7권2호
    • /
    • pp.74-85
    • /
    • 1987
  • Performances of 3 different aerodynamic analytical models, single multiple and double multiple stream tube, for vertical axis Darrieus turbine were analyzed comparatively. From the study it has been found that the models derived from stream tube assumptions can be useful for simple prediction of basic design characteristics of Darrieus turbine. But, for a large tip speed and solidity ratios, the models has shown a certain limit in its applicability according to the formulation scheme applied. The results have shown that for the case having large tip speed and solidity ratios the consideration due to stream conditions, such as trailing vortices or wakes, should be included for accurate prediction of the aerodynamic performances of Darrieus turbine.

  • PDF

Polynomial modeling of confined compressive strength and strain of circular concrete columns

  • Tsai, Hsing-Chih
    • Computers and Concrete
    • /
    • 제11권6호
    • /
    • pp.603-620
    • /
    • 2013
  • This paper improves genetic programming (GP) and weight genetic programming (WGP) and proposes soft-computing polynomials (SCP) for accurate prediction and visible polynomials. The proposed genetic programming system (GPS) comprises GP, WGP and SCP. To represent confined compressive strength and strain of circular concrete columns in meaningful representations, this paper conducts sensitivity analysis and applies pruning techniques. Analytical results demonstrate that all proposed models perform well in achieving good accuracy and visible formulas; notably, SCP can model problems in polynomial forms. Finally, concrete compressive strength and lateral steel ratio are identified as important to both confined compressive strength and strain of circular concrete columns. By using the suggested formulas, calculations are more accurate than those of analytical models. Moreover, a formula is applied for confined compressive strength based on current data and achieves accuracy comparable to that of neural networks.

CRASHWORTHINESS IMPROVEMENT OF VEHICLE-TO-RIGID FIXED BARRIER IN FULL FRONTAL IMPACT USING NOVEL VEHICLE'S FRONT-END STRUCTURES

  • ELMARAKBI A. M.;ZU J. W.
    • International Journal of Automotive Technology
    • /
    • 제6권5호
    • /
    • pp.491-499
    • /
    • 2005
  • There are different types of vehicle impacts recorded every year, resulting in many injuries and fatalities. The severity of these impacts depends on the aggressivety and incompatibility of vehicle-to-roadside hardware impacts. The aim of this paper is to investigate and to enhance crashworthiness in the case of full barrier impact using a new idea of crash improvement. Two different types of smart structures have been proposed to support the function of the existing vehicle. The work carried out in this paper includes developing and analyzing mathematical models of vehicle-to-barrier impact for the two types of smart structures. It is proven from analytical analysis that the mathematical models can be used in an effective way to give a quick insight of real life crashes. Moreover, it is shown that these models are valid and flexible, and can be useful in optimization studies.

A Survey on IEEE 802.11 MAC Analytical Modeling for MAC Performance Evaluation

  • Heo, Ung;Yu, Changfang;You, Kang-Soo;Choi, Jae-Ho
    • 융합신호처리학회논문지
    • /
    • 제12권2호
    • /
    • pp.119-127
    • /
    • 2011
  • The paper surveys various analytical models for IEEE 802.11 medium access control protocols and critically discusses recent issues developing in wireless mobile ad hoc networks and their MACs. The surveyed MAC protocols include the standard IEEE 802.11 MAC suites such as IEEE 802.11 DCF, IEEE 802.11 PCF, IEEE 802.11e EDCA, and IEEE 802.11 ad hoc mode; and also the newer, de facto MAC protocols. We study the analytic models of the standard MAC suites followed by the newer analytic models that have been published in recent years. Also, the paper tries to include most of current literatures discussing analytic modeling of MAC in conjunction to some critical issues such as contention among ad hoc nodes, hidden terminal problems, and real-time service support.

Comparative Evaluation of Two Analytical Models for Microwave Scattering from Deciduous Leaves

  • Oh, Yi-Sok
    • 대한원격탐사학회지
    • /
    • 제20권1호
    • /
    • pp.39-46
    • /
    • 2004
  • The generalized Rayleigh-Gans (GRG) approximation is usually used to compute the scattering amplitudes of leaves smaller or comparable to a wavelength, while the physical optics (PO) approach with the resistive sheet approximation is commonly used for leaves larger or comparable to the wavelength. In this paper, the scattering amplitudes of an elliptical leaf are computed using those theoretical scattering models (GRG and PO) at different frequencies. The accuracies of the analytical models for microwave scattering from deciduous leaves are investigated by comparison with the precise estimation by the method of moment (MoM). It was found that both the PO approach and the GRG approximation can be used alternatively for computing the scattering matrices of natural deciduous leaves at P-, L-, C- and X-band frequencies.