• Wind and Structures
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• v.19 no.1
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• pp.59-73
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• 2014

This paper presents the results of wind tunnel studies and numerical studies on a '+' plan shaped tall building. The experiment was carried out in an open circuit wind tunnel on a 1:300 scale rigid model. The mean wind pressure coefficients on all the surfaces were studied for wind incidence angle of $0^{\circ}$ and $45^{\circ}$. Certain faces were subjected to peculiar pressure distribution due to irregular formation of eddies caused by the separation of wind flow. Moreover, commercial CFD packages of ANSYS were used to demonstrate the flow pattern around the model and pressure distribution on various faces. k-${\varepsilon}$ and SST viscosity models were used for numerical study to simulate the wind flow. Although there are some differences on certain wall faces, the numerical result is having a good agreement with the experimental results for both wind incidence angle.

• International Journal of CAD/CAM
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• v.6 no.1
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• pp.125-137
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• 2006

Nowadays, many commercial CAD systems support history-based, constraint-based and feature-based modeling. Unfortunately, most systems fail during the re-evaluation phase when various kind of topological changes occur. This issue is known as "persistent naming" which refers to the problem of identifying entities in an initial parametric model and matching them in the re-evaluated model. Most works in this domain focus on the persistent naming of atomic entities such as vertices, edges or faces. But very few of them consider the persistent naming of aggregates like shells (any set of faces). We propose in this paper a complete framework for identifying and matching any kind of entities based on their underlying topology, and particularly shells. The identifying method is based on the invariant structure of each class of form features (a hierarchical structure of shells) and on its topological evolution (an historical structure of faces). The matching method compares the initial and the re-evaluated topological histories, and computes two measures of topological similarity between any couple of entities occurring in both models. The naming and matching method has been implemented and integrated in a prototype of commercial CAD Software (Topsolid).

• ETRI Journal
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• v.34 no.5
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• pp.791-794
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• 2012

We propose an efficient framework to realistically render 3D faces with a reduced set of points. First, a robust active appearance model is presented to detect facial features in the projected faces under different illumination conditions. Then, an adaptive simplification of 3D faces is proposed to reduce the number of points, yet preserve the detected facial features. Finally, the point model is rendered directly, without such additional processing as parameterization of skin texture. This fully automatic framework is very effective in rendering massive facial data on mobile devices.

• Journal of the Korean Society of Safety
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• v.13 no.1
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• pp.34-39
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• 1998

This paper describes a evaluation method of sound power radiated from the vibrating faces of a single stage gear box using sound radiation. The vibration caused from meshing gears is transmitted to the gear box faces through shafts and bearings. A Boundary Element Method (BEM) is developed to calculate the sound power radiated from the faces with their velocity response which is based on the Building Block Approach (BBA). Radiation efficiency as well as the sound intensity on the surface of the gear box is also calculated. Sound power of the gear box is larger in the case that bearings have offset to the wall of the gear box than that bearings are on the center of the gear box. The sound power increases with the augmentation of the offset.

• Journal of the Korean Ceramic Society
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• v.31 no.3
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• pp.249-256
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• 1994

By surface structure and X-ray topographic observation, growth mechanism of NAB single crystal grown by TSSG technique using a BaB4O7 flux was studied. Surface structure of grown crystals were investigated by optical microscope. Growth history and crystal defects included within grown crystal were investigated using X-ray topography. The {001} faces were grown by 2-D nucleation growth. As decreasing cooling rate, growth mechanism of {111} and {11} was changed from 2-D nucleation growth to the growth by screw dislocation. Only surface striations developed parallel to a-axis were observed on {010} faces. Growth sector of NAB crystals were divided into {001}, {111}, {010}, {021}, {11}. The inclusion which was usually trapped between {001} faces was investigated.

• International Journal of Fuzzy Logic and Intelligent Systems
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• v.3 no.1
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• pp.87-92
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• 2003

This paper describes a system for tracking multiple faces in an input video sequence using facial convex hull based facial segmentation and robust hausdorff distance. The algorithm adapts skin color reference map in YCbCr color space and hair color reference map in RGB color space for classifying face region. Then, we obtain an initial face model with preprocessing and convex hull. For tracking, this algorithm computes displacement of the point set between frames using a robust hausdorff distance and the best possible displacement is selected. Finally, the initial face model is updated using the displacement. We provide an example to illustrate the proposed tracking algorithm, which efficiently tracks rotating and zooming faces as well as existing multiple faces in video sequences obtained from CCD camera.

• Structural Engineering and Mechanics
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• v.55 no.4
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• pp.885-900
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• 2015

This paper introduces Romberg-Richardson's method as one of the numerical integration tools for computation of stress intensity factor in a pre-cracked specimen subjected to a complex stress field across the crack faces. Also, the computation of stress intensity factor for various stress fields using existing three methods: average stress over interval method, piecewise linear stress method, piecewise quadratic method are modified by using Richardson extrapolation method. The direct integration method is used as reference for constant and linear stress distribution across the crack faces while Gauss-Chebyshev method is used as reference for nonlinear distribution of stress across the crack faces in order to obtain the stress intensity factor. It is found that modified methods (average stress over intervals-Richardson method, piecewise linear stress-Richardson method, piecewise quadratic-Richardson method) yield more accurate results after a few numbers of iterations than those obtained using these methods in their original form. Romberg-Richardson's method is proven to be more efficient and accurate than Gauss-Chebyshev method for complex stress field.

• Journal of the Society of Naval Architects of Korea
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• v.32 no.4
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• pp.87-96
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• 1995

This study is concerned with the overall buckling analysis of sandwich plates under biaxial loads by applying the Rayleigh-Ritz method, which are considered to buckle simultaneously in overall from of core and thin faces together. In order to study the effects of boundary conditions on the buckling behaviors, the simply supported, flexed and it's combined boundary conditions are considered as well as the effects of material characteristics of core and thin faces of sandwich plates on the buckling behaviors.

• Smart Media Journal
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• v.7 no.4
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• pp.61-69
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• 2018

Multi-tracking of general objects and specific faces is an important topic in the field of computer vision applicable to many branches of industry such as biometrics, security, etc. The rapid development of deep neural networks has resulted in a dramatic improvement in face recognition and object detection problems, which helps improve the multiple-face tracking techniques exploiting the tracking-by-detection method. Our proposed method uses face detection trained with a head dataset to resolve the face deformation problem in the tracking process. Further, we use robust face features extracted from the deep face recognition network to match the tracklets with tracking faces using Hungarian matching method. We achieved promising results regarding the usage of deep face features and head detection in a face tracking benchmark.

• Proceedings of the Korea Information Processing Society Conference
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• 2022.11a
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• pp.653-655
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• 2022

Face aging aims to synthesize future face images by reflecting the age factor on given faces. In recent years, deep learning-based approaches have made outstanding progress in simulating the aging process of the human face. However, generating accurate and high-quality aging faces is still intrinsically difficult. We propose a new method that incorporates gender information into the model, which achieves comparable and stable performance. Experimental results demonstrate that our method can preserve the identity well and generate diverse aged faces.