• Transactions of the Korean Society of Mechanical Engineers B
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• v.28 no.6
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• pp.713-725
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• 2004

The two-dimensional motion of a freely falling circular cylinder in an infinite fluid is investigated numerically using combined formulation. The effect of vortex shedding on the motion of a freely falling cylinder is clearly seen: as the streamwise velocity of the cylinder increases due to gravity, the periodic vortex shedding induces a periodic motion of the cylinder. This motion in turn affects the flow field, which is manifested by the generation of the angular velocity vector of the cylinder parallel to the cross product of the gravitational acceleration vector and the transverse velocity vector of the cylinder. A correlation of St-Re relationship for a freely falling circular cylinder is drawn from the present results. The Strouhal number for a freely falling circular cylinder is found to be smaller than that for a fixed circular cylinder when the two Reynolds numbers based on the streamwise terminal velocity of a freely failing circular cylinder and the free stream velocity of a fixed one are the same. From "thought experiments", it is shown that the transverse motion of the cylinder plays a crucial role in reducing the Strouhal number and has an effect of reducing the Reynolds number from the viewpoint of the pressure coefficient. The mechanism of this reduction in the Strouhal number is revealed by the fact that the freely falling cylinder experiences a smaller lift force than the fixed one due to the transverse motion resulting in the retardation of the vortex shedding.

• Journal of the Korean Society for Precision Engineering
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• v.19 no.5
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• pp.149-158
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• 2002

Recently, the minimum line width shows a tendency to decrease and the multi-level increases in semiconductor. Therefore, a planarization technique is needed and chemical mechanical polishing(CMP) is considered as one of the most suitable process. CMP accomplishes a high polishing performance and a global planarization of high quality. However there are several defects in CMF, such as micro-scratches, abrasive contaminations and non-uniformity of polished wafer edges. Wet etching process including spin-etching can eliminate the defects of CMP. It uses abrasive-free chemical solution instead of slurry. On this study, ILD(Interlayer-Dielectric) was removed by CMP and wet etching process using DHF(Diluted HF) in order to investigate the possibility of planrization by wet etching mechanism. In the thin film wafer, the results were evaluated from the viewpoint of material removal rate(MRR) and within wafer non-uniformity(WIWNU). And the pattern step heights were also compared for the purpose of planarity characterization of the patterned wafer. Moreover, Chemical polishing process which is the wet etching process with mechanical energy was introduced and evaluated for examining the characteristics of planarization.

• Science of Emotion and Sensibility
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• v.14 no.2
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• pp.293-300
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• 2011

The CGI(Computer-generated Image) techniques provide designers with an effective means of creating design artifacts in an automatic way. It has been pointed that two important activities while applying the CGI techniques are both image generation and managemental issues for the generated images. By applying automatic generation techniques for creation of images, designers can acquire benefits in that they can produce free style results in a simple way. Along with such benefits, it is also important for designer to identify and to establish well defined mechanisms for storing vast quantity of auto-generated CGIs. However, it is problematic to assign key-words and to classify abstract images mainly because they lack an analogy of the real world entities. This paper presents classification scheme for the abstract CGIs by applying classification and description criteria from the viewpoint of both design elements and emotional elements. Effective classification and specification can help designers build and retrieve desired images in an easy way, and make management process more simple and effective.

• Korean Institute of Interior Design Journal
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• v.21 no.2
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• pp.56-64
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• 2012

This paper has tried to analyze the characteristics of space in Korean traditional architecture by deconstructive concept through connecting Lao-tzu's theory, the main discourse of East and West, with Derrida's deconstructionism theory. Derrida's philosophical term of differance(diff$\acute{e}$rance) is similar to Tao of Lao-tzu. It is because Derrida emphasized the relationships with others by trying the strategy of overcoming dichotomous thinking by this term. Tao of Lao-tzu also has the relative characteristics that cannot be concluded by one sole meaning. Like this, Derrida and Lao-tzu are against traditional and dichotomous way of thinking. In this point of view, this study has set Derrida's deconstruction theory and Lao-tzu's thinking as the common viewpoint of this world. And through the phrase of Tao Te Ching which means deconstructive Tao, deconstructive space design vocabulary was derived as mixed no-boundary, shape of no-shape, transcendence of time and space. The deconstructive characteristics of traditional space by case study analysis of Lao-tzu's deconstructive space design are as follows: First, it is not a specific or detailed shape but an unlimited possibility that can be transformed into something else, moving and changing endlessly and has a borderless beauty. Second, it is nothing itself but creates various shapes, as if it exists without shape. Third, it is a relative and unlimited space and pursuits a free form as a non-conceptional shape without any system or value.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.20 no.2
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• pp.101-105
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• 2010

Silicon electrode and ring in a plasma etcher those are in contact with harsh plasma suffer from periodic heating and cooling during their lifetime. This causes the silicon components failure due to thermal stress remaining the persistent slip bands (PSBs) on their surfaces. The factors that determine the lifetime of silicon electrode and ring were discussed with respect to silicon ingot. The impurity level and the average defect concentration measured with glow discharge mass spectrometer (GDMS) and microwave photo-conductance decay (${\mu}$-PCD) were compared with the grade of silicon ingots those are divided to slip-free and slip-allowed ingot. Some silp-allowed samples showed planar defects along <110> direction on {001} surface. The role of these defects was suggested from the viewpoint of the lifetime of silicon components.

• Journal of Broadcast Engineering
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• v.25 no.3
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• pp.439-448
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• 2020

In this paper, we propose a modified optimization algorithm for point cloud matching of multi-view RGB-D cameras. In general, in the computer vision field, it is very important to accurately estimate the position of the camera. The 3D model generation methods proposed in the previous research require a large number of cameras or expensive 3D cameras. Also, the methods of obtaining the external parameters of the camera through the 2D image have a large error. In this paper, we propose a matching technique for generating a 3D point cloud and mesh model that can provide omnidirectional free viewpoint using 8 low-cost RGB-D cameras. We propose a method that uses a depth map-based function optimization method with RGB images and obtains coordinate transformation parameters that can generate a high-quality 3D model without obtaining initial parameters.

• Asia-Pacific Journal of Business Venturing and Entrepreneurship
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• v.9 no.2
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• pp.175-186
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• 2014

Dream Start Project purposes to provide equal opportunity for the child in the poverty. This project is conducted the last six years, there are voices of worry for the limit of the project performance. Therefore, this study aims to analyse the effectiveness of project and suggest activation plan of Dream Start from the viewpoint of users. This study use focus group interview to explore needs assessment for development of Dream Start Project. In conclusion, the project provides positive outcomes for children and their parents in terms of psychology, education and health etc. Children have increased their basic learning ability through the learning support. They have improved confidence and positiveness. The vaccine was as effective in health promotion. Dream Start had the effect of raising community consciousness. The relationship between children and their parents were smoothly through parent education. Free learning support has brought the economic effects. This project had the effect of improving welfare consciousness of the parents. This study presents the development plan of the business to reflect the users' assessment.

• The Research Journal of the Costume Culture
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• v.18 no.6
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• pp.1153-1164
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• 2010

The objective of this study is to analyze the coordination images seen in comprehensive fashion items and their features. This will be done from the viewpoint of both the creativity as well as functional characteristics of items and images. For the method of study, I explored the idea of "snood" style, analyzing its features of 42 pictures appearing from the 2006 S/S to 2010 F/W collection. It is important to note that "snood" style has the characteristics of both a muffler and turtleneck. With looping design connected at both ends, it can be placed around the neck or head, creating the image of wearing a hood. After having examined the selected data and pictures, one can largely divide the exclusive high-fashion image categories into three types: feminine, avant-garde, and finally, active & functional sportive image. First, the orthodox image is widely accepted by most as it has forever evolved within the original tradition of the practically functional muffler(scarf). Second, since the metamorphic image tends to lend itself to free ideas, you can wear a snood around the shoulders like a collar. Worn together with the same type of clothing, the snood can be seen as an effective suit. Third, the aim of image emphasis is to highlight certain points, or make some features more noticeable, as a means of possibly attracting more interest and attention. The image of snood arises out of the use of shapes, colors, and other accessory parts. As mentioned earlier, snood stands out as an independent item instead of just being an accessory to clothing. Its primary function as a style coordinator is emphasized in order to create more distinctive fashion images. Through this study, I thereby intend to provide fashion style data on the latest trends, and high-fashion codes of snood coordination.

• Journal of the Korean Society for Nondestructive Testing
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• v.21 no.3
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• pp.269-276
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• 2001

Ultrasonic testing of composite materials is much more difficult than that of isotropic materials, because of the beam skew phenomenon caused by their elastic anisotropy. An established analytical method exists for elastic wave propagation in anisotropic media as a result of previous research efforts. Yet, due to the complexity of the analytical method, solution of real problems must resort to the numerical method. In this work, analytical solutions have first been obtained for the wavefield due to a point source in a unidirectional fiber-reinforced composite, which may be modeled as transversely isotropic. Then, the corresponding numerical solutions have been obtained using the mass-spring lattice model(MSLM). The two solutions have agreed well with each other. Other problems such as reflection from free boundaries and scattering from cracks have also been solved numerically, and the results have been investigated from the viewpoint of wave mechanics. The numerical model whose validity has been confirmed by this work will be of great use in simulating ultrasonic testing of composite materials.

• Journal of Physiology & Pathology in Korean Medicine
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• v.25 no.1
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• pp.92-99
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• 2011

Topical natural antioxidants are a useful strategy for the prevention of oxidative stress mediated cardiovascular disease including atherosclerosis. From the viewpoint of this underlying principle, the screening of natural plant extracts with scavenging activity for pro-oxidant reactive species is a primary requirement for the development of new topical antioxidant formulations. Euryale ferox Salisbury (EF) is botanical name and it's pharmaceutical name is EURYALES SEMEN (ES). The stems and branchs of EF have been used as a traditional herbal medicine for the treatment of dysentery, diarrhea, leucorrhoea, incontinence and paralysis of joint. In this study, the antioxidant activity of extract from EF was studied in vitro methods by measuring the antioxidant activity and free radical scavenging activity by TEAC and DPPH, measuring the scavenging effects on reactive oxygen species (ROS) [superoxide anion, hydroxyl radical] and on reactive nitrogen species (RNS) [nitric oxide and peroxynitrite] as well as measuring the inhibitory effect on $Cu^{2+}$-induced human LDL oxidation. The EF extracts were found to have a potent scavenging activity, as well as an inhibitory effect on LDL oxidation. In conclusion, the EF extracts have antioxidative effects in vitro system, which can be used for developing pharmaceutical drug against oxidative stress and chronic degenerative disease such as atherosclerosis.