• 방송공학회논문지
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• 제25권5호
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• pp.808-811
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• 2020

본 논문은 랜덤 무향 칼만 필터를 이용하여 키넥트 카메라 센서의 오차를 최소화하는 방법을 제안한다. RGB 값과 깊이(Depth) 정보를 제공하는 RGB+D 카메라는 센서의 오차로 인해 뻐대 검출 과정에서 성능 저하의 원인을 제공한다. 기존에는 다양한 필터링 기법을 이용하여 오차를 제거하였으나 비선형 잡음을 효과적으로 제거하는데 한계가 있었다. 이에 본 논문에서는 비선형 잡음 특성을 예측하고 업데이트하기 위해 랜덤 무향 칼만 필터를 적용하였으며 이를 바탕으로 뻐대 검출 성능을 높이고자 하였다. 실험 결과 제안한 방법은 기존의 방법에 비해 정량적 오차를 줄였으며 뼈대의 3D 검출 시 우수한 결과를 확인할 수 있었다.

• Geomechanics and Engineering
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• 제23권3호
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• pp.217-225
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• 2020

In this paper, the thermoelastic interactions in a two-dimension porous body are studied. This problem is solved by using the Green and Lindsay (GL) generalized thermoelasticity model under fractional time derivative. The derived approaches are estimated. with numeral results which are applied to the porous mediums in simplifying geometrical. The bounding plane surface of the present half-space continuum is subjected to a pulse heat flux. We use the Laplace-Fourier transforms methods with the eigenvalues approach to solve the problem. The numerical solutions for the field functions are obtained numerically using the numerical Laplace inversion technique. The effects of the fractional parameter and the thermal relaxation times on the temperature field, the displacement field, the change in volume fraction field of voids distribution and the stress fields have been calculated and displayed graphically and the obtained results are discussed.

• Journal of applied mathematics & informatics
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• 제27권1_2호
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• pp.315-326
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• 2009

The unknown parameters in regression models are usually estimated by using various existing methods. There are several existing methods, such as the least squares method, which is the most common one, the least absolute deviation method, the regression quantile method, and the asymmetric least squares method. For the nonlinear time series regression models, which do not satisfy the general conditions, we will compare them in two ways: 1) a theoretical comparison in the asymptotic sense and 2) an empirical comparison using Monte Carlo simulation for a small sample size.

• Water Engineering Research
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• 제2권3호
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• pp.187-196
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• 2001

An approximate analytical solution of a nonlinear hydro-thermo coupled diffusion equation is derived using the dimensionless form of the equation and transformation method. To derive an analytical solution, it is drastically assumed that the product of first order derivatives in the non-dimensionalized governing equation has little influence on the solution of heat and moisture behavior problem. The validity of this drastic assumption is demonstrated. Some numerical simulation is performed to investigate the applicability of a derived approximate analytical solution. The results show a good agreement between analytical and numerical solutions. The proposed solution may provide a useful tool in the verification process of the numerical models. Also, the solution can be used for the analysis of one-dimensional coupled heat and moisture movements in unsaturated porous media.

• 국제초고층학회논문집
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• 제1권1호
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• pp.53-59
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• 2012

With the rise in CPU power and the generalization and popularity of computers, engineering practice also changed from hand calculations to 3D computer models, from elastic linear analysis to 3D nonlinear static analysis and 3D nonlinear transient dynamic analysis. Thanks to holistic design approach and current trends in freeform and contemporary architecture, BIM concept is no longer a dream but also a reality. BIM is not just providing a media for better co-ordination but also to shorten the round-the-clock time in updating models to match with other professional disciplines. With the parametric modeling tools, structural information is also linked with BIM system and quickly produces analysis and design results from checking to fabrication. This paper presents a new framework which not just linked the BIM system by means of parametric mean but also create and produce connection FE model and fabrication drawings etc. This framework will facilitate structural engineers to produce well co-ordinate, optimized and safe structures.

• 한국해양공학회지
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• 제20권6호
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• pp.35-40
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• 2006

In recent years, there's been strong demand for seawalls that havea gentle slope and permeability that serveswater affinity and disaster prevention from wave attack. The aim of this study is to examine wave transformation, including wave run-up that propagates on the coastal structures. A numerical model based on the weak nonlinear dispersive Boussinesq equation, together with the unsteady nonlinear Darcy law for fluid motion in permeable layer, is developed. The applicability of this numerical model is examined through Deguchi and Moriwaki's hydraulic model test on the permeable slopes. From this study, it is found that the proposed numerical model can predict wave transformation and run-up on the gentle slope with a permeable layer, but can't show accurate results for slopes steeper than about 1:10.

• 대한기계학회논문집
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• 제9권5호
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• pp.621-626
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• 1985

본 논문에서는 정해를 구하기 어려운 이질의 세개의 층으로 된 비피압대수층 내에서의 물의 비정상유동에 대한 이론 및 실험에 대하여 연구하고자 한다.

• Geomechanics and Engineering
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• 제21권1호
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• pp.85-93
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• 2020

In this article, the generalized thermoelastic theory with fractional derivative is presented to estimate the variation of temperature, the components of stress, the components of displacement and the changes in volume fraction field in two-dimensional porous media. Easily, the exact solutions in the Laplace domain are obtained. By using Laplace and Fourier transformations with the eigenvalues method, the physical quantities are obtained analytically. The numerical results for all the physical quantities considered are implemented and presented graphically. The results display that the present model with the fractional derivative is reduced to the Lord and Shulman (LS) and the classical dynamical coupled (CT) theories when the fractional parameter is equivalent to one and the delay time is equal to zero and respectively.

• International Journal of Naval Architecture and Ocean Engineering
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• 제7권3호
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• pp.540-558
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• 2015

Maneuvering oblique towing test is simulated in a Computational Fluid Dynamic (CFD) environment to obtain the linear and nonlinear velocity dependent damping coefficients for a DTMB 5512 model ship. The simulations are carried out in freely accessible OpenFOAM library with three different solvers, rasInterFoam, LTSInterFoam and interDyMFoam, and two turbulence models, $k-{\varepsilon}$ and SST $k-{\omega}$ in presence of free surface. Turning and zig-zag maneuvers are simulated for the DTMB 5512 model ship using the calculated damping coefficients with CFD. The comparison of simulated results with the available experimental shows a very good agreement among them.

• Asia pacific journal of information systems
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• 제30권3호
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• pp.547-567
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• 2020

As the complexity of managing online personal information is increasing and data breach incidents frequently occur, online users feel a loss of control over their privacy. Such a situation leads to their cynical attitudes towards privacy protection, called privacy cynicism. This study aims to examine the role of privacy cynicism in online users' privacy behaviors. Data were gathered from a survey that 281 people participated in and were analyzed with covariance-based structural equation modeling. The findings of this study reveal that privacy cynicism has not only a direct influence on disclosure intention but also moderates an effect of privacy concerns on the intention. The analytical results also indicate that there is a nonlinear effect of privacy cynicism on the outcome variable. This study developed the concept of privacy cynicism—a phenomenon that significantly affects online privacy behavior but has been rarely examined. The study is an initial research into the nature and implications of privacy cynicism and furthermore clarified its role by the nonlinear relationship between privacy cynicism and the willingness to disclose personal information.