• Journal of the Korean Data and Information Science Society
• /
• 제22권3호
• /
• pp.565-574
• /
• 2011

The exponenetiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of shape parameter and reliability function in the exponenetiated half triangle distribution based on Type-I hybrid censored data. Here we consider conjugate prior and noninformative prior and obtained corresponding posterior distributions. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.

• 충청수학회지
• /
• 제29권1호
• /
• pp.59-71
• /
• 2016

To obtain more accurate approximation of the true images in the deblurring problems, the weighted global generalized cross validation(GCV) function to the inverse problem with multiple right-hand sides is suggested as an efficient way to determine the regularization parameter. We analyze the experimental results for many test problems and was able to obtain the globally useful range of the weight when the preconditioned global conjugate gradient linear least squares(Gl-CGLS) method with the weighted global GCV function is applied.

• Communications for Statistical Applications and Methods
• /
• 제18권5호
• /
• pp.603-613
• /
• 2011

Exponentiated distribution has been used in reliability and survival analysis especially when the data is censored. In this paper, we derive Bayesian estimation of the shape parameter, reliability function and failure rate function in the exponentiated distribution family based on Type-II right censored data. We here consider conjugate prior and noninformative prior and corresponding posterior distributions are obtained. As an illustration, the mean square errors of the estimates are computed. Comparisons are made between these estimators using Monte Carlo simulation study.

• 태양에너지
• /
• 제6권1호
• /
• pp.60-69
• /
• 1986

Two-dimensional finite difference numerical analysis is used to study conjugate natural convection heat transfer from a horizontal conducting tube with one vertical axial fin. By increasing dimensionless fin length ($L_F$), the mean total Nusselt number of the upward fin is slightly less than that of the downward fin at $L_F\;{\le}\;0.18$ and is higher than that of the downward fin at $L_F\;>\;0.18$. However comparing the upward fin and the downward fin with the no fin, the mean total Nusselt numbers of downward fin and upward fin at $L_F=0.30$ are increased approximately 4.01% and 5.51%, respectively. As Rayleigh number, Prandtl number and Biot number increase, the mean total and the mean tube Nusselt numbers are increased, but as wall thickness increases, the mean total and the mean tube Nusselt numbers are decreased. As the fin conduction parameter increases, the mean total Nusselt number is slightly increased because of increasing the mean fin Nusselt number.

• Nuclear Engineering and Technology
• /
• 제49권8호
• /
• pp.1636-1644
• /
• 2017

The main purpose of this article is to describe the magnetohydrodynamic stagnation point flow of Walter-B nanofluid over a stretching sheet. The phenomena of heat and mass transfer are based on the involvement of thermal radiation and chemical reaction. Characteristics of Newtonian heating are given special attention. The Brownian motion and thermophoresis models are introduced in the temperature and concentration expressions. Appropriate variables are implemented for the transformation of partial differential frameworks into sets of ordinary differential equations. Plots for velocity, temperature, and nanoparticle concentration are displayed and analyzed for governing parameters. The skin friction coefficient and local Nusselt and Sherwood numbers are studied using numerical values. The temperature and heat transfer rate are enhanced within the frame of the thermal conjugate parameter.

• 한국군사과학기술학회지
• /
• 제5권2호
• /
• pp.195-206
• /
• 2002

The conjugate heat transfer from the simulated module in a horizontal channel with the variation of inlet air temperature is experimentally investigated. The aim of this study is to estimate temperature difference between a module and inlet air. This study is performed with the variation of parameters that are inlet air temperature(Ti=25~$55^{\circ}C), thermal resistance( $R_c$=0.05, 4.11, 158 K/W), inlet air velocity(Vi=0.1~1.5m/s), and input power(Q=3, 7 W). The results show that the effect of inlet air temperature is little, at the case of using conductive board. And input power was most effective parameter on the temperature difference between module and Inlet air.

• 한국수학교육학회지시리즈B:순수및응용수학
• /
• 제16권2호
• /
• pp.243-254
• /
• 2009

The main purpose of this paper is to use the methods of Lattice Dynamical System to establish a global model, which extends the Walrasian evolutionary cobweb model in an independent single local market to the global market evolution over an infinite chain of many local markets interacting each other through a diffusion of prices between them. For brevity of the model, we assume linear decreasing demands and quadratic supplies with naive predictors, and investigate the spatially homogeneous global price dynamics and show that the dynamics is topologically conjugate to that of well-known logistic map and hence undergoes a period-doubling bifurcation route to chaos as a parameter varies through a critical value.

• 한국수학사학회지
• /
• 제27권6호
• /
• pp.395-402
• /
• 2014

When the circle inscribed in a square is projected to a picture plane, one sees, in general, an ellipse in a convex quadrilateral. This ellipse is poorly described in the works of Alberti and Durer. There are one parameter family of ellipses inscribed in a convex quadrilateral. Among them only one ellipse is the perspective image of the circle inscribed in the square. We call this ellipse "the projected ellipse." One can easily find the four tangential points of the projected ellipse and the quadrilateral. Then we show how to find the center of the projected ellipse. Finally, we describe a pair of conjugate vectors for the projected ellipse, which finishes the construction of the desired ellipse. Using this algorithm, one can draw the perspective image of the squared-circle tiling.

• 한국전자파학회논문지
• /
• 제24권12호
• /
• pp.1148-1157
• /
• 2013

수동형 UHF RFID 시스템에서 태그의 최대 인식 거리는 태그 칩과 안테나 사이의 임피던스 정합과 리더의 프로토콜 파라미터 설정에 따라 직접적인 영향을 받는다. 하지만 칩 임피던스 산출 방법과 프로토콜 파라미터가 최대 인식 거리에 미치는 영향에 대한 연구는 전무한 실정이다. 따라서 본 논문에서는 기존 방법(데이터 시트와 전용 RFID 테스터를 이용)과 제안된 방법(상용 리더를 이용)으로 칩의 임피던스를 산출한 후 이 값으로 태그를 제작해 인식 거리를 비교함으로써, 인식 거리를 극대화하는 칩 임피던스 산출 방법에 대한 비교분석을 하였다. 제안된 방법으로 산출된 임피던스에 공액 정합된 태그가 상용리더를 이용한 인식 거리 측정 실험에서 기존 방법과 비교하여 최대 73 % 인식 거리의 개선을 보였다.

• 한국소음진동공학회:학술대회논문집
• /
• 한국소음진동공학회 1998년도 춘계학술대회논문집; 용평리조트 타워콘도, 21-22 May 1998
• /
• pp.340-346
• /
• 1998

In order to improve the prediction of dynamic behavior in structures, several lower vibration modes from FFT analysis through experiments are used to update the mechanical properties followed by the updated frequencies from numerical analysis. Performance index consists of the sum of error norms between the chosen frequencies and corresponding frequencies from numerical analysis. As an updating process of the natural frequencies, the optimization algorithm based on conjugate gradient method is adopted. The gradient of performance index is calculated using the sensitivity of selected eigenvalues with respect to each design parameter. The mechanical properties of lamina, E$\_$l/, E$\_$2/, .nu.$\_$12/ and G$\_$12/, are design parameters for the updating process. The proposed method is applied to predict the dynamic behavior of composite laminated plates of [0]$\_$8T/ and [.+-.45]$\_$2S/ separately or interchangeably. Also, the mixed case for [0]$\_$8T/ and [.+-.45]$\_$2S/ is exarm'ned to check the possibility for the improved prediction generally. The good agreement is obtained between the measured frequencies and the numerical ones. Based on the results for all the cases studied, the proposed approach has a clear potential in characterizing the mechanical properties of composite lamina.