• Title/Summary/Keyword: Analytic solution

Search Result 633, Processing Time 0.032 seconds

A Study on Analytic Hierarchy Proces for Construction Planning -Research on Examples of Railway Route Selection- (건설계획 수립시 계층분석적 의사결정법 적용방안에 관한 연구 -철도노선 선정시 활용사례 연구-)

  • Sohn, Jin-Hyeon;Cha, Cheol
    • Journal of the Korean Society of Industry Convergence
    • /
    • v.10 no.4
    • /
    • pp.249-254
    • /
    • 2007
  • Recently, the items of construction planning have magnified and specialized and the problems occurring at the first step of the construction planing process have complicated. In this research, AHP(Analytic Hierarchy Process) method which is simple to apply and clear to decide has been proposed when a people making a plan at the first step of the construction planing process. As an example, the best solution has been obtained in a railway construction line choice that consist of various items by applying for this method, which proves the possibility of application of this method to the complicated problems.

  • PDF

Enterprise Knowledge Management System(KMS) Construction - using Business Analytics Solution : A Case of KB Card (Business Analytics를 이용한 기업 지식관리시스템 구축 사례 연구)

  • Lee, Chung Keun;Lee, Soo Yong;Lee, Gun Hee
    • Knowledge Management Research
    • /
    • v.14 no.5
    • /
    • pp.137-149
    • /
    • 2013
  • Although business Intelligence system is introduced to many companies over the past decade, The result of business benefits from BI investment are not so significant than expected. But still successful BI system can provide the ability to analyse business information in order to support and improve management decision making across a broad range of business activities. In recently, Business Analytics System(BA) is emerging as advanced alternative of outdated and inefficient BI System. This study is focus on constructing procedure of BA system in KB card company, which is major credit card company in South Korea. In practice there were just few works that mentioned well-designed environment of KMS system, and other contribution of this study is to make a platform which invoke revelation of collective intelligence in data analytic professional users group.

  • PDF

A Design of Engine Exhaust Ejector for Smart UAV (스마트무인기의 엔진 배기이젝터 설계에 관한 연구)

  • Lee, Chang-Ho;Kim, Jai-Moo
    • Proceedings of the Korean Society of Propulsion Engineers Conference
    • /
    • 2006.11a
    • /
    • pp.403-406
    • /
    • 2006
  • An ejector is designed for the purpose of engine bay cooling. The primary flow of the ejector is the exhaust gas of the PW206C turboshaft engine. The mass flow of secondary flow is calculated by using the approximate analytic equation. For the purpose of verification of approximate analytic method, comparison is made with the results of Navier-Stokes turbulent flow solution. According to the results of CFD, the mixing of two flows is incomplete due to the short length of mixing duct.

  • PDF

Charateristics of Adhesive Joint between Concrete and FRP Using Numerical Method (수치 모델을 사용한 콘크리트-FRP 부착면의 거동 특성)

  • 조정래;조근희;박영환;김병석
    • Proceedings of the Korea Concrete Institute Conference
    • /
    • 2003.11a
    • /
    • pp.219-222
    • /
    • 2003
  • Substantial experimental and theoretical work exists on the bond characteristics of FRP-concrete adhesive joints. Experimental studies show that the bond strength cannot always increase with an increase in the bond length, and that the ultimate strength is strongly influenced by the concrete strength. To solve this feature, analytic solutions based on fracture mechanics are widely used, and the local shear stress-slip curve with a softening branch is known as more rational model. The analytic solution, however, cannot describe various shapes of model curve. In this study, numerical method using interface element is introduced to express various shapes of model curve. Characteristics of adhesive joint is investigated for the shapes of the model curve and their parameters. And the numerical solutions are compared with the test results of CFRP sheet adhesive joints.

  • PDF

A Study on the Application of Macro Air-gap Element for Magnetic Flux Distribution Analysis of Electric Machinery by F.E.M. (유한요소법에 의한 전기기계의 자속분포해석을 위한 MACRO 공선요소 적용에 관한 연구)

  • Dal-Ho Im
    • The Transactions of the Korean Institute of Electrical Engineers
    • /
    • v.35 no.11
    • /
    • pp.479-486
    • /
    • 1986
  • It is necessary to consider a rotor movement in dynamic analysis on the flux distribution of electric machinery by FEM. Therefore, if air-gap domain was subdivided into triangular elements, computation results contain errors due to variation of element shape in air-gap because the nodal points corresponding to the rotor are displaced in analyzing domain for the time difference. In order to reduce this errors, the paper presents a application of a Macro Air-gap Element that interpolation function is obtained analytically and a means to join it with linear triangular elements in the rotating machine or in the linear machine. At the end of paper, setting up analytic domain model, it compares analytic solution with the computation results of Macro Air-gap Element appliction and that of linear triangular element subdivision only to each cases of nodal displacement. And it carries out that errors due to variation of element shape are reduced effectively by application of a Macro air-gap element.

  • PDF

Direct Differentiation Method for Shape Design Sensitivity Analysis of Axisymmetric Elastic Solids by the BEM and Shape Optimization of Turbin Disc (경계요소법에 의한 축대칭 탄성체의 형상설계 민감도해석을 위한 직접미분법과 터빈 디스크의 형상최적설계)

  • Lee, Bu-Yun
    • Transactions of the Korean Society of Mechanical Engineers A
    • /
    • v.20 no.5
    • /
    • pp.1458-1467
    • /
    • 1996
  • A direct differentiationmethod is presented for the shape design sensitivity analysis of axisymmeetric elastic solids. Based on the exisymmetric boundary integralequaiton formulation, a new boundary ntegral equatio for sensitivity analysis is derived by taking meterial derivative to the same integral identity that was used in the adjoint variable melthod. Numerical implementation is performed to show the applicaiton of the theoretical formulation. For a simple example with analytic solution, the sensitivities by present method are compared with analytic sensitivities. As an application to the shape optimization, an optimal shape of a gas turbine disc toinimize the weight under stress constraints is found by incorporating the sensitivity analysis algorithm in an optimizatio program.

The analysis of aoustic scattering problems by Indirect PFBEM with cylinder model (파워흐름경계요소법을 이용한 원통형 구조물에 대한 음파산란해석)

  • Jeong, Pill-Woo;Hong, Suk-Yoon;Lee, Ho-Won;Kwon, Hyun-Wung
    • Proceedings of the Korean Society for Noise and Vibration Engineering Conference
    • /
    • 2005.11b
    • /
    • pp.90-93
    • /
    • 2005
  • Power Flow Boundary Element Method(PFBEM) has been used as a promising tool for radiation problems in the midium-to-high frequency. PFBEM is the numerical method that applies boundary element technique to Power Flow Analysis (PFA). Indirect PFBEM is developed for acoustic scattering problems in the open field and in various frequency. To verify the analytic results of indirect PFBEM for acoustic scattering problems are compared with those of SYSNOISE, and the results using two analytic methods show a good agreement.

  • PDF

Full-Range Analytic Drain Current Model for Depletion-Mode Long-Channel Surrounding-Gate Nanowire Field-Effect Transistor

  • Yu, Yun Seop
    • JSTS:Journal of Semiconductor Technology and Science
    • /
    • v.13 no.4
    • /
    • pp.361-366
    • /
    • 2013
  • A full-range analytic drain current model for depletion-mode long-channel surrounding-gate nanowire field-effect transistor (SGNWFET) is proposed. The model is derived from the solution of the 1-D cylindrical Poisson equation which includes dopant and mobile charges, by using the Pao-Sah gradual channel approximation and the full-depletion approximation. The proposed model captures the phenomenon of the bulk conduction mechanism in all regions of device operation (subthreshold, linear, and saturation regions). It has been shown that the continuous model is in complete agreement with the numerical simulations.

An analytical model for the prediction of strip temperatures in hot strip rolling (열간 압연 중 판의 온도 분포 모델 개발)

  • Kim, J.B.;Lee, J.H.;Hwang, S.M.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
    • /
    • 2009.04a
    • /
    • pp.97-102
    • /
    • 2009
  • In hot strip rolling, sound prediction of the temperature of the strip is vital for achieving the desired finishing mill draft temperature (FDT). In this paper, a precision on-line model for the prediction of temperature distributions along the thickness of the strip in the finishing mill is presented. The model consists of an analytic model for the prediction of temperature distributions in the inter-stand zone, and a semi-analytic model for the prediction of temperature distributions in the bite zone in which thermal boundary conditions as well as heat generation due to deformation are predicted by finite element-based, approximate models. The prediction accuracy of the proposed model is examined through comparison with predictions from a finite element process model.

  • PDF

ENHANCED SEMI-ANALYTIC METHOD FOR SOLVING NONLINEAR DIFFERENTIAL EQUATIONS OF FRACTIONAL ORDER

  • JANG, BONGSOO;KIM, HYUNJU
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • v.23 no.4
    • /
    • pp.283-300
    • /
    • 2019
  • In this paper, we propose a new semi-analytic approach based on the generalized Taylor series for solving nonlinear differential equations of fractional order. Assuming the solution is expanded as the generalized Taylor series, the coefficients of the series can be computed by solving the corresponding recursive relation of the coefficients which is generated by the given problem. This method is called the generalized differential transform method(GDTM). In several literatures the standard GDTM was applied in each sub-domain to obtain an accurate approximation. As noticed in [19], however, a direct application of the GDTM in each sub-domain loses a term of memory which causes an inaccurate approximation. In this work, we derive a new recursive relation of the coefficients that reflects an effect of memory. Several illustrative examples are demonstrated to show the effectiveness of the proposed method. It is shown that the proposed method is robust and accurate for solving nonlinear differential equations of fractional order.