• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2007.05a
• /
• pp.281-281
• /
• 2007

• Journal of Korea Multimedia Society
• /
• v.14 no.5
• /
• pp.691-702
• /
• 2011

Recently, several researchers have attempted to combine human visual perception and computer graphics. Cole et. al. suggest the study results in which line drawing algorithm in computer graphics characterize the properties of line drawing made by artists. The paper also evaluates CG line drawing algorithms depending on whether people recognize effectively specific 3D shape from the image made by those CG line drawing algorithms. However, human recognizes the shape of objects more effectively in image made by BRDF shading model than line drawing algorithm. It means that the shading factor is important to recognize shape with human perception. In this paper, we analyze the correlation between shading made by human artists and that made by CG shading algorithms. The study is to characterize the mathematical properties of artists' shading and CG shading. This type of analysis can guide the future development of new CG shading algorithm in computer graphics for the purpose of shape perception.

• Transactions of Materials Processing
• /
• v.17 no.7
• /
• pp.501-506
• /
• 2008

In this study, a forming magnesium alloy circular cup was simulated accounting for heat transfer at elevated temperatures. In order to predict the failure of magnesium alloy sheet during simulation, the forming limit diagram, which is used in sheet metal forming analysis to determine the criterion for failure, was investigated. For the failure prediction in the simulation accounting for heat transfer, the forming limit diagram for a temperature the same as the temperature of the blank element was used. The result of the simulation showed that the drawn depth increases with the increase of the die-holder temperature, and is in accord with the experimental results above the die-holder temperature of $150^{\circ}C$. The forming limit diagram provided a good guide for the failure prediction of warm forming simulation accounting for heat transfer. In addition, the effect of the tool shoulder radius on the drawn depth at various tool temperatures is verified using the simulation conditions which agreed with the experimental results.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.10a
• /
• pp.66-70
• /
• 2008

In this study, the formability of AZ31B magnesium alloy sheets was investigated by the analytical and experimental approaches. Tensile tests and limit dome height tests were rallied out at several temperatures between $25^{\circ}C$ and $300^{\circ}C$ to obtain the mechanical properties and forming limit diagram (FLD). The FLD-based criterion considering the strain-path and the blank temperature was used to predict the forming limit in a deep-drawing process of cross-shaped cup by finite element analysis. This criterion proved to be very useful in determining the optimal process conditions such as blank shape, punch velocity, minimum comer radius, fillet size, and so on, through the comparison between FEA and experimental data. In particular, the temperature of each tool that provided the best formability of the blank was determined by coupled temperature-deformation analyses. A practical method that can greatly reduce the forming time by increasing the punch speed during the forming process was suggested.

• Design & Manufacturing
• /
• v.12 no.3
• /
• pp.42-47
• /
• 2018

Recently, in the surge of global environmental issues, there has been a great attention to lightweight materials in purpose of saving energy. Magnesium alloys not only have low specific gravity, and superb specific stiffness, but are also excellent in blocking vibrations and electromagnetic waves. So demand for this material is getting bigger rapidly throughout the industry. In this study, we examined the improvement of formability of magnesium alloy AZ31 material in warm working. Drawing, bending and shearing process were carried out by varying the forming temperature and the forming speed, and the influence of the variables on each process was studied. In the experiments, the high forming temperature and low forming speed results in high formability in the drawing process and the bending process. In the shearing process, as the forming temperature increases, the length of the fracture decreases.

• Proceedings of the Korean Society for Technology of Plasticity Conference
• /
• 2008.05a
• /
• pp.370-373
• /
• 2008

It is known that the temperatures of die, punch, holder and punch pad need to be kept different to get better formability in Mg sheet forming processes. Heating and cooling channels are usually equipped in each tool to assign different temperature. This study focused on the optimal design of the heating and cooling channels for a cross-shaped deep drawing die set. While the die and blankholder were heated to and kept at $250^{\circ}C$ by using heat cartridges, the punch and punch pad were kept at much lower temperature than that of the die and blankholder by water circulating through cooling channels. All the approaches were done by numerical analyses, aiming to maximize the cup height and to minimize the punch corner radius without any failure.

• Journal of Korean Medical classics
• /
• v.20 no.4
• /
• pp.119-126
• /
• 2007

The biological and pathological states of lung, spleen, liver and kidneys are determined by nature and emotion of sorrow, anger, joy and pleasure, It is considered that the music, besides medicine or acupuncture, can be a way of treating as a therapeutics for the treatment of Sasangin's diseases. This study is to find out a way of music therapy for the treatment of Sasangin's diseases. The ways of music therapy in each constitution based on 'the great and small of Viscera and Bowels' and 'the exhale and inhale, the drawing in and sending out' are as follows: 1. In case of Soeumin, a skip going up melodic progression, dotted rhythm and the major triad harmonic progression are recommended to improve the Qi of warm Yang. 2. In case of Soyangin, in regular sequence down melodic progression, a sixteenth note and the minor triad harmonic progression are recommended to improve the Qi of cool Yin. 3. In case of Taeumin, in regular sequence going up melodic progression, a sixteenth note and the bright and active the major triad harmonic progression are recommended to improve the Qi of dispersing exhale. 4. In case of Taeyangin, a skip down melodic progression, a quarter note and a diminished triad harmonic progression are recommended to improve the Qi of gathering inhale.

• The Journal of Internal Korean Medicine
• /
• v.20 no.1
• /
• pp.48-56
• /
• 1999

This study has been carried out to investigate Brain in Nei-jing. The results of this study were as follows. 1. Kidney energy becomes the marrow by warm caring function of Meong-mun(命門) and the marrow becomes brain by ascending and gathering between a hole Back-hoi(百會) and a hole pung-ji(風池) 2. Brain is a sea of the marrow that five vital organs are eraporated togather. 3. In Nei-jing(內經), there is a explanation the connectin between brain and mind, thanking by drawing in a concept of head. 4. Brain regulrates physical excercise. 5. There is a direct connection between brain and biosis. 6. Brain achieves function of sense, relating with the five sensory organs. 7. Brain controls a change of emotion. 8. Brain has immunological function.

• Journal of Science and Technology Studies
• /
• v.14 no.2
• /
• pp.127-164
• /
• 2014

This essay examines the motivations, goals, and assumptions of those who are participating in the appropriate technology movement in contemporary South Korea. In addition to analyzing books, articles, presentation materials, and media reports written by or about the "appropriate technologists," I have interviewed a few of them to hear their thoughts on appropriate technologies as well as inappropriate technologies. They choose to work on appropriate technology out of their good will for people in need, their Christian faith, and their pride in Korea's rapid and successful development. As a result, the appropriate technology movement in Korea does not engage in a critical evaluation of current sociotechnical systems, but instead takes an ethical and paternalistic stance in accepting and improving the given situation. Its apolitical character is effective in drawing a large number of participants, but it also limits their imagination and the movement's potential influence. Moreover, the movement's focus on "the other 90%" leads the participants to frame appropriate technology as something for "them" or "locals" rather than as something for "all of us." This essay concludes by suggesting that the appropriate technology movement in Korea should expand its scope from an ethical pursuit of technology to a political engagement with technology.

• The Journal of Information Systems
• /
• v.32 no.1
• /
• pp.23-51
• /
• 2023

Purpose: Live commerce is a new type of electronic commerce in combination with live streaming services. It is expected to increase virtual presence in the context of online shopping by overcoming a lack of social interactions between sellers and buyers which have been raised as a limitation in electronic commerce. Drawing on the studies of communication media, this study examines how live commerce contributes to the increase of virtual presence which consists of telepresence and social presence. Telepresence refers to a buyer's perception that he or she is present at the physical shopping mall during live shopping streaming whereas social presence refers to a buyer's perception of social interaction with a seller which is human warm, social, sensitive, and personal. In this study, we verify key determinants of virtual presence and its consequences. More specifically, this study proposes virtual presence contributes to the increase of buyers' trust in products and further purchase intentions. Furthermore, we verify influential factors of virtual presence from the technical and influencer perspectives of live commerce. Design/methodology/approach: To test the proposed hypotheses, the partial least squares (PLS) analysis is conducted with a total of 250 data collected on users with experience in the TaoBao live streaming shopping platform. Findings: The results show that first, telepresence and social presence are increased by visibility, media richness and attractiveness in the context of live shopping streaming. Second, buyers' trust in product trust and purchase intentions are positively influenced by telepresence and social presence. Finally, buyers' trust in product has a direct, positve effect on their purchase intentions. Overall, the findings offer new insights into the studies of electronic commerce by introducting the concepts of virtual presence and media richness from the literature of communication media in the field of live commerce.