• 한국윤활학회:학술대회논문집
• /
• 한국윤활학회 1998년도 제27회 춘계학술대회
• /
• pp.131-138
• /
• 1998

In this study, a numerical procedure to solve a contact problem has been developed. The procedure takes the advantage of signal processing technique in frequency domain to achieve the shorter computer processing time. The Boussinesq's equation was adopted as the response function. This procedure is applicable to the non-periodic surface profile as well as the periodic one. The validity of this procedure has been established by comparing the numerical results with the exact solutions. The effectiveness of this procedure is lied on the shorter computing time than any other contact analysis algorithm.

• 한국지반공학회:학술대회논문집
• /
• 한국지반공학회 1999년도 봄 학술발표회 논문집
• /
• pp.407-414
• /
• 1999

A simple seismic design procedure for pile foundation using PAR and LPILE$\^$plus/ was proposed. A case of pile foundation under a simple bridge was selected and analyzed. The calculated horizontal movements, shear forces and moments were compared with those evaluated by the numerical exact solutions, and the farmers had similar trends with the tatters.

• 설비공학논문집
• /
• 제14권3호
• /
• pp.191-198
• /
• 2002

Cooling tower design procedure was set up using conventional Merkel theory, The design data could be different depending on the characteristic curve that the engineer chose. It reveals that the consistent and reasonable criteria are required based on the exact information of the cooling tower Performance. In this study, an off-design performance analysis program for a counterflow-type cooling tower was developed and verified by comparing with experimental data. Also, the off-design performance with various operating conditions was analyzed.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
• /
• pp.200-205
• /
• 1998

Although discretization methods such as the transfer matrix method (TMM) and the finite element method (FEM) have played an important role in the design or analysis of rotor-bearing systems, continuous system modeling and analysis are often desirable especially for sensitivity analysis or design. The present paper proposes a comprehensive modeling procedure to obtain exact solution of general rotor-bearing systems. The proposed method considers a Timoshenko beam model and makes use of complex coordinate in the formulation. The proposed method provides exact eigensolutions and frequency response functions (FRFS) of general multi-stepped rotor-bearing systems. The first numerical example compares the proposed method with FEM. The numerical study proves that the proposed method is very efficient and useful for the analysis of rotor-bearing systems.

• Structural Engineering and Mechanics
• /
• 제15권1호
• /
• pp.71-81
• /
• 2003

The governing differential equation for buckling of a one-step bar with the effect of shear deformation is established and its exact solution is obtained. Then, the exact solution is used to derive the eigenvalue equation of a multi-step bar. The new exact approach combining the transfer matrix method and the closed form solution of one step bar is presented. The proposed methods is convenient for solving the entire and partial buckling of one-step and multi-step bars with various end conditions, with or without shear deformation effect, subjected to concentrated axial loads. A numerical example is given explaining the proposed procedure and investigating the effect of shear deformation on the critical buckling force of a multi-step bar.

• Smart Structures and Systems
• /
• 제26권3호
• /
• pp.361-371
• /
• 2020

Exact solution for nonlinear behavior of clamped-clamped functionally graded (FG) buckled beams is presented. The effective material properties are considered to vary along the thickness direction according to exponential-law form. The in-plane inertia and damping are neglected, and hence the governing equations are reduced to a single nonlinear fourth-order partial-integral-differential equation. The von Kármán geometric nonlinearity has been considered in the formulation. Galerkin procedure is used to obtain a second order nonlinear ordinary equation with quadratic and cubic nonlinear terms. Based on the mode of the corresponding linear problem, which readily satisfy the boundary conditions, the frequencies for the nonlinear problem are obtained using the Jacobi elliptic functions. The effects of various parameters such as the Young's modulus ratio, the beam slenderness ratio, the vibration amplitude and the magnitude of axial load on the nonlinear behavior are examined.

• 대한전기학회논문지
• /
• 제45권2호
• /
• pp.256-264
• /
• 1996

In this paper, the decentralized suboptimal H$_{2}$ filtering problem is considered. An additional term is added to the centralized optimal H$_{2}$ filter so that the whole filter is decentralized. We derive a necessary and sufficient condition for existence of proposed decentralized filters By employing the solution procedure for the exact model matching problem, we obtain a set of decentralized H$_{2}$ filters, and choose a suboptimal filter from this set of decentralized H$_{2}$ filters.

• Journal of Mechanical Science and Technology
• /
• 제14권3호
• /
• pp.331-337
• /
• 2000

A numerical procedure for contact analysis and calculating subsurface stress was developed. The procedure takes the advantage of signal processing technique in frequency domain to achieve shorter computing time. Boussinesq's equation was adopted as a response function in contact analysis. The validity of this procedure was proved by comparing the numerical results with the exact solutions. The fastness of this procedure was also compared with other algorithm.

• Communications for Statistical Applications and Methods
• /
• 제25권5호
• /
• pp.559-568
• /
• 2018

Gene classification can involve complex order-restricted inference. Examining gene expression pattern across groups with order-restriction makes standard statistical inference ineffective and thus, requires different methods. For this problem, Roy's union-intersection principle has some merit. The M-estimator adjusting for outlier arrays in a microarray study produces a robust test statistic with distribution-insensitive clustering of genes. The M-estimator in conjunction with a union-intersection principle provides a nonstandard robust procedure. By exact permutation distribution theory, a conditionally distribution-free test based on the proposed test statistic generates corresponding p-values in a small sample size setup. We apply a false discovery rate (FDR) as a multiple testing procedure to p-values in simulated data and real microarray data. FDR procedure for proposed test statistics controls the FDR at all levels of ${\alpha}$ and ${\pi}_0$ (the proportion of true null); however, the FDR procedure for test statistics based upon normal theory (ANOVA) fails to control FDR.

• 한국산학기술학회논문지
• /
• 제17권2호
• /
• pp.66-74
• /
• 2016

본 연구는 소책자를 이용한 간호정보제공이 내시경 점막하 박리술 환자의 시술 전 불안 및 불확실성에 미치는 효과를 알아보기 위한 유사실험 연구로 비동등성 대조군 전후 시차설계 연구이다. 자료 수집은 2013년 2월 13일 부터 4월 26일 까지 46명을 대상으로 시행되었다. 대조군 23명은 기존의 중재 방법인 구두설명과 표준화된 양식 없이 일반적인 시술전 교육을 받았고 실험군 23명은 본 연구자가 개발한 소책자를 통한 간호정보제공을 받았다. 수집된 자료는 SPSS 21.0을 이용하여 ${\chi}^2$ test, Fisher's exact t-test로 분석하였다. 실험군은 대조군보다 불안(t=3.319, p=.002), 불안 행동반응(t=3.508, p=.001)이 유의하게 감소하였으나 불확실성은 차이를 보이지 않았다(t=.745, p=.460). 소책자를 이용한 간호정보제공은 위내시경시술 환자의 시술 전 불안을 감소시키는데 유용한 간호중재이다.