• Explosives and Blasting
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• v.23 no.3
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• pp.27-42
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• 2005

An explosion modeling technique was developed by using the spherical discrete element code, $PFC^{3D}$, which can be used to model the dynamic stress wave propagation phenomenon. The modeling technique is simply based on an idea that the explosion pressure should be applied to a $PFC^{3D}$ particle assembly not in the form of an external force (body force), but in the form of a contact force (surface force). The stress wave propagation modeling was conducted by simulating the experimental approach based on the Hopkinson's effect combined with the spatting phenomenon that had previously been developed to determine the dynamic tensile strength of Inada granite. As a result, the stress wave velocity obtained by the proposed modeling technique was 4167 m/s, which is merely $3\%$ lower than the actual wave velocity of 4300 m/s for an Inada granite.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.8 no.5
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• pp.1096-1101
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• 2004

The 3-D shape use to effect of movie, animation, industrial design, medical treatment service, education, engineering etc.... But it's not easy to make 3-D shape from the information of 2-D image. There are two methods in restoring 3-D video image through 2-D image; First the method of using a laser; Secondly the method of acquiring 3-D image through stereo vision. Instead of doing two methods with many difficulties, I figure out the method of simple 3-D image in this research paper. We present here a simple and efficient method, called direct calibration, which doesn't require any equations at all. The direct calibration procedure builds a lookup table(LUT) linking image and 3-D coordinates by a real 3-D triangulation system. The LUT is built by measuring the image coordinates of a grid of known 3-D points, and recording both image and world coordinates for each point; the depth values of all other visible points are obtained by interpolation.

• The Journal of Korean Association of Computer Education
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• v.8 no.1
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• pp.105-115
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• 2005

An environment model that is constructed using a single image has the problem of a blurring effect caused by the fixed resolution, and the stretching effect of the 3D model caused when information that does not exist on the image occurs due to the occlusion. This paper introduces the registration and integration method using multiple images to resolve the above problem. This method can represent parallax effect and expand the environment model to represent wide range of environment. The segmentation-based environment modeling method using multiple images can build a detail model with optimal resolution.

• Journal of The Korean Association of Information Education
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• v.20 no.6
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• pp.535-542
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• 2016

In this study, we examined the perceptions of teachers and students to utilize 3D educational content. We conducted a survey about the effect of utilizing 3D educational content, interest in the 3D content, the advantages and problems of utilizing 3D education in class by targeting at elementary school teachers and elementary school students, Surveyed are students and teachers who participated the contest for 3D content development. Research results, both teachers and students were very positive about the educational effects of 3D content and they take advantage of educational content, as well as higher interest in 3D making education. We also found that they require overall support including 3D education-relevant materials and teacher training school in the field.

• Journal of the Korean Society of Radiology
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• v.14 no.1
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• pp.45-51
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• 2020

The purpose of this study was to analyze the educational effect of self-directed learning method using 3D printed anatomy on radiological science students. The subjects were 32 students (20 males and 12 females) in the second year of radiological science at university. They were divided two groups as a non-active student group and an active student group. A learning method was self-directed learning using 3D printed anatomical structures, and the effects of quantitative learning improvement were evaluated before and after the learning. The qualitative evaluation of the students was analyzed on the Likert's 5-point scale for the interest, satisfaction, and learning effects (memorization convenience of anatomy name, radiography Interpret ability, understanding on bones structure, and X-ray projection technique). As a result, the enhancement of learning improved 65.4% on average, and all students got scored high on all variables. Especially non-active student groups showed higher correlation coefficients in all variables except interest and radiography interpret than active student groups. These results might suggest that self-directed learning using 3D printed anatomical structures could have a positive educational effect on radiological science students.

• Cartoon and Animation Studies
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• s.36
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• pp.259-280
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• 2014

Animation is showing the highest record in entertainment around the world and writing the history of 3D animation again. The image contents effect thanks to the proper introduction of the state-of-art digital technology, which is one of the causes of the outstanding entertainment and the factual reproduction of the images, provided an opportunity to transmit the meaning of image aesthetics, which is a virtual reality and image reproduction through the reality realization of photo medium, and to reinterpret the boundary of virtual reality. Especially, the development of digital contents technology due to scientific technologies demolishes the boundary of virtual reality and reality and creates the effect of making viewers be absorbed by realizing the virtual reality by means of 3D reality images which highlight the special characteristic of photos. The aspect of the contents technology and image aesthetics which can be interpreted in a view point beyond the existing concept of reality is found in the aura theory of Benjamin and in the Simulacres of Baudrillard. The 3D image by photo-reality herein presents various suggestions in the aspect of real existence of spatial expression, the meaning creation process of reality, the existence value of virtual images.

• Journal of the Ergonomics Society of Korea
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• v.14 no.2
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• pp.25-32
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• 1995

The physiological change of eyes while viewing 3D TV was investigated. The change of pupil size was used as the measure of evaluation. The results are as follows : (1) The pupil size decreases after viewing 2D and 3D image and the the tendency is more critical with 3D images. (2) The indoor illumination has a significant effect on the pupil size in both 2D and 3D cases. (3) Less chage of pupil size were observed under the indoor illumination. Thus, if we only focus on the visual load on the eye, for viewing 3D image, it will be better to use indoor illumination.

• Journal of the Korean Institute of Oriental Medical Informatics
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• v.15 no.1
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• pp.77-84
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• 2009

Objectives : The aim of the present study is to evaluate the effects Rehmannia glutinosa, Radix puerariae, Semen coicis, Fructus hordei, Cortex acanthopanacis, Fructus chaenomelis, or Radix glycyrrhizae extracton 3T3-L1 preadipocytes differentiation. Methods : We adopted Oil Red O staining methods to observe the formed lipid droplets. And the amount of lipids in adipocytes was measured using absorptiometric analysis. Results : The extracts of Rehmannia glutinosa, Radix puerariae, Semen coicis, Fructus hordei, Cortex acanthopanacis, Fructus chaenomelis, or Radix glycyrrhizae stimulated the preadipocytes differentiation and lipid droplet formation. And the complex extract of the traditional herbal medicines stimulated there actions more than single extracts. Conclusions : The extract of Rehmannia glutinosa, Radix puerariae, Semen coicis, Fructus hordei, Cortex acanthopanacis, Fructus chaenomelis, or Radix glycyrrhizae has stimulatory effects. on adipogenesis. Moreover, the complex extract of the traditional herbal medicines has more effect than single extracts.

• JSTS:Journal of Semiconductor Technology and Science
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• v.14 no.5
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• pp.649-657
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• 2014

In this study, the effects of the frequency-dependent characteristics of through-silicon vias (TSVs) on the performance of 3D ICs are examined by evaluating a typical interconnection structure, which is composed of 32-nm CMOS inverter drivers and receivers connected through TSVs. The frequency-domain model of TSVs is extracted in S-parameter from a 3D electromagnetic (EM) method, where the dimensional variation effect of TSVs can be accurately considered for a comprehensive parameter sweep simulation. A parametric analysis shows that the propagation delay increases with the diameter and height of the TSVs but decreases with the pitch and liner thickness. We also investigate the crosstalk effect between TSVs by testing different signaling conditions. From the simulations, the worst signal integrity is observed when the signal experiences a simultaneously coupled transition in the opposite direction from the aggressor lines. Simulation results for nine-TSV bundles having regular and staggered patterns reveal that the proposed method can characterize TSV-based 3D interconnections of any dimensions and patterns.

• Journal of the Korean Society of Manufacturing Technology Engineers
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• v.26 no.1
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• pp.6-12
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• 2017

In a large 3D printer when the cooler, which cools the filament, acts in one direction, the area directly exposed to the cooling is cooled to the proper temperature. However, the cooling effect on the opposite area is relatively less. It was found in experiments that filaments with a thickness of over 2 mm exhibit the cooling problem in one directional cooling. Consequently, cooling was performed to prevent the flow-down and to produce firm support leading to an improvement in product quality in extrusion. Further, the lay-up of a 3D printer with five guides combined with a duct was achieved. Analysis showed that the improvement in the cooling effect enables stable extrusion and lay-up and thus, reduces fabrication time.