• Journal of the Korean Crystal Growth and Crystal Technology
• /
• v.29 no.2
• /
• pp.71-76
• /
• 2019

Recently, the demand of labels for product management is increasing, as the automation system becomes more common. the development of functional labels which can be used in various environments has been rapidly proceeded. In the case of a printed circuit board, barcode labels with thermal and chemical stability are generally used due to a high temperature process around $300^{\circ}C$ and chemical cleaning in the manufacturing process. However, the yellowing phenomenon of labels that can lower the resolution of printed barcode image still needs to be prevented. In this study, we prepared a composite coating layer using a silica inorganic binder and a titanium dioxide white pigment, and developed a functional labels with thermal and chemical stability. The silica inorganic binder prepared by sol-gel process was confirmed to show excellent adhesion and abrasion resistance with the polyimide film. The white coating layer could be formed on the polyimide film with mixing the silica inorganic binder and titanium dioxide white pigment. The prepared coating layer showed excellent whiteness and glossiness above $400^{\circ}C$. The excellent chemical stability of the coating layer was also confirmed by the chemical treatment with acidic (pH 1.6) and basic (pH 13.6) cleaners.

• Journal of Korean Society of Occupational and Environmental Hygiene
• /
• v.31 no.2
• /
• pp.173-183
• /
• 2021

Objectives: This study evaluated the skin permeability of lawsone in henna hair dyes to understand the exposure characteristics of henna hair dyes in the human body. It examined the protective effects of protectants by applying protectants A, B, and C to test skin. Methods: Skin absorption tests were conducted using Franz diffusion cells according to OECD test guideline 428. After applying one kind of natural henna hair dye and chemical henna hair dye, respectively, to a standardized pig skin model, samples of receptor fluid were collected at 1h, 3h, 6h, and 24h. The skin permeation of lawsone was determined using HPLC. After the skin absorption experiment, the skin to which hair dye was applied was analyzed to determine the residual amount of lawsone in the skin. Results: The cumulative permeation of both natural and chemical henna hair dyes increased over time, and the natural henna hair dye had a flux value (t=3.194, p<.05) high both in the K_p value (t=3.207, p<.05) and the residual amount (t=22.701, p<.001). For skin treated with a protectant, the cumulative permeation of natural henna hair dye 24h control and the cumulative permeation of protectant A, B, and C increased over time. Flux and K_p values were in the order control > protectant A > protectant C > protectant B. The residual amount (F=4.469, p<.05) was in the order of protectant C > protectant A > protectant B > control. At 3h, the dye application time of natural henna hair dye, the lawsone flux value (F=4.454, p<.05) and K_p value (F=4.455, p<.05) were higher in the control group than in the protectant groups. The 24h cumulative permeation of the chemical henna hair dye increased with time in both the control and the protectant groups, and the flux and K_p values were in the order of protectant A > protectant C > protectant B > control. The residual amount (F=7.901, p<.01) was in the order of protectant B > protectant A> protectant C > control. Conclusions: Within the normal dyeing time for henna hair dye (three hours for natural henna hair dyes and 30 minutes for chemical henna hair dyes) lawsone skin penetration was not observed even when no protective agent was applied. After that time, however, evidence of skin penetration and retention of lawsone and the protective effect of protective agents were observed.

• Trans-
• /
• v.13
• /
• pp.59-90
• /
• 2022

Short-form content, which means "short video content within 10 minutes," is rapidly emerging as a recent trend among MZ generations based on the fact that it can be viewed whenever there is a short running time, and they are physically short, colorful, and deliver a lot of information in a compressed time, showing differences in both long-form content and format. In addition, entertainment videos such as information delivery videos, eating shows, web entertainment, and dance challenges are mainly produced and distributed, so there is no need to take expertise as a creative work of video experts, and consumers often become producers by directly participating in production using low-end equipment such as smartphones. For these reasons, shortform content creates new image styles rather than general existing image forms such as long-form contents, and this study focuses on changes in editing styles. This study summarized the following five characteristic changes by analyzing the editing style of short form content that has changed compared to long form content according to the 'visual' aspect. The use of frames, memes, screen division, blue screen, and subtitles are included, and by organizing each characteristic, we identified the editing style of shortform content that has emerged as a recent trend and learned about the changes.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.3
• /
• pp.25-29
• /
• 2022

Recently, the importance of electronic packaging technology has been attracting attention, and heterogeneous integration technology in which chips are stacked out-of-plane direction is being applied to the electronic packaging field. The 2.5D integration circuit is a technology for stacking chips using an interposer including TSV, and is widely used already. Therefore, it is necessary to make the interposer mechanically reliable in the packaging process that undergoes various thermal processes and mechanical loadings. Considering the structural characteristics of the interposer on which several thin films are deposited, thermal stress due to the difference in thermal expansion coefficients of materials can have a great effect on reliability. In this study, the mechanical reliability of the metal pad for wire bonding on the silicon interposer against thermal stress was evaluated. After heating the interposer to the solder reflow temperature, the delamination of the metal pad that occurred during cooling was observed and the mechanism was investigated. In addition, it was confirmed that the high cooling rate and the defect caused by handling promote delamination of the metal pads.

• Journal of the Microelectronics and Packaging Society
• /
• v.29 no.3
• /
• pp.37-42
• /
• 2022

Recently, the semiconductor package structures are becoming thinner and more complex. As the thickness decrease, interfacial delamination due to material mismatch can be further maximized, so the reliability of interface is a critical issue in industry field. Especially, the polymers, which are widely used in semiconductor packaging, are significantly affected by the temperature and moisture. Therefore, in this study, the delamination prediction at the interface of package structure was performed through finite element analysis considering the moisture absorption and desorption under the various temperature conditions. The material properties such as diffusivity and saturated moisture content were obtained from moisture absorption test. The hygro-swelling coefficients of each material were analyzed through TMA and TGA after the moisture absorption. The micro-shear test was conducted to evaluate the adhesion strength of each interface at various temperatures considering the moisture effect. The finite element analysis of interfacial delamination was performed that considers both deformation due to temperature and moisture absorption. Consequently, the interfacial delamination was successfully predicted in consideration of the in-situ moisture desorption and temperature behavior during the reflow process.

• Journal of Popular Narrative
• /
• v.26 no.1
• /
• pp.41-76
• /
• 2020

Recently, the cinema industry faced a crisis on the rise of various media platforms such as Netflix, Amazon Prime, IPTV, and Kakao Page. The rate of film release in the theater has become ever shorter, and the secondary consumption of film through IPTV, tablet, PC, or mobile has seen a drastic increase. In the midst of this new media-geography, the most significant change in recent years would be the rise of the 'fantasy film' genre. This paper explores the conditions and characteristics of fantasy films in the way in which the genre has been constituted, and delves into particular aspects that its contents contain. This is an attempt to understand the sociology of the birth of a new genre. In this process, this paper will ask two frequently raised questions in regard to this genre. The first is to ask whether we can discern fantasy from reality, and the second is to examine whether the fantasy genre implicates certain social subversion. These two questions aim to discover how fantasy forms a relationship with reality and what this means. To do so, this paper will trace the genealogy of the fantasy film genre in Korea and analyze recent big hits such as the series as the model case of digital fantasy film. Through this exploration, this paper will be able to provide a new sociology of the fantasy film production and consumption in the 21^st century Korea.

• Journal of the Microelectronics and Packaging Society
• /
• v.30 no.3
• /
• pp.64-72
• /
• 2023

In this study, after transferring graphene on a Cu substrate and printing a Sn-3.0Ag-0.5Cu Pb-free solder paste on the Cu substrate, effects of the transferred graphene on formations and growths of intermetallic compound (IMC) at the interface between the Cu substrate and the solder were reported during processes of reflow soldering and isothermal aging for 1000 h with various temperatures (125, 150, and 175 ℃). Thicknesses of Cu₆Sn₅ and Cu₃Sn IMCs at the interfaces with graphene were decreased during the reflow soldering and isothermal aging processes compared to those without graphene. The transferred graphene layers also showed that the growth rate constant and square of growth rate constant which related to the growth mechanisms of Cu₆Sn₅ and Cu₃Sn IMCs with t he t emperature a nd t ime of t he i sothermal aging c ould dramatically decreased.

• Korean Journal of Culture and Social Issue
• /
• v.14 no.1_spc
• /
• pp.367-390
• /
• 2008

The primary purpose of this study is to investigate the college students' implicit theory of Korean creativity. This study deals with the degree to which the students exploit the creativity, and the obstacles for them to exploit the creativity. Another purpose of this study is to explore their implicit knowledge of Korean creative environments. The results are as follows. The implicit knowledge of Korean creativity could be characterized by the following key words: 'flexibility', 'application', 'transformation', 'originality', 'perseverance', 'not being stereotyped', 'esthetic flavor' and 'understanding-new-by-exploring-old'. Students thought themselves to be more or less creative. Students in art and physical education, and male students estimated themselves more creative than other discipline and female. They thought that socio-institutional factors such as educational system focused on the college entrance test are the most serious obstacles against creativity. About half of the students thought the creative persons would have been raised in poor family whereas other students thought differently. The home environment of the creative person was thought to be characterized by the words such as democratic, free and encouraging. Creative persons were thought to be maladaptive school life, but good at peer relations. This study will be used as a pioneer research which suggest a model of Korean creativity.

• Journal of Dental Rehabilitation and Applied Science
• /
• v.40 no.3
• /
• pp.159-168
• /
• 2024

Through the use of intraoral scanners, it is possible to obtain intraoral scan impressions and produce prostheses. This approach is also being attempted not only in dentate patients but also in edentulous patients. However, obtaining scans of edentulous areas can be more challenging than scanning dental areas, and there may be limitations, especially in capturing the details of the mucosal tissues. On the other hand, when obtaining impressions with intraoral scanners, simultaneous recording of the occlusal relationship of the maxilla and mandible can reduce the number of patient visits and expedite the restoration process. In this case, we aimed to combine the advantages of direct intraoral scanning and indirect digital impressions obtained after traditional impression-taking by merging two types of scan files. Consequently, in patients with partially edentulous arches, we sought to provide effective interim prostheses through direct and indirect digital model impressions and report our findings accordingly.

• Journal of Institute of Control, Robotics and Systems
• /
• v.7 no.9
• /
• pp.717-722
• /
• 2001

This paper presents a methodology on the backward path tracking control of a trailer type robot which consists of two parts: a tractor and a trailer. It is difficult to control the motion of a trailer vehicle since its dynamics is non-holonomic. Therefore, in this paper, the modeling and parameter estimation of the system using a real-coded genetic algorithm(RCGA) is proposed and a backward path tracking control algorithm is then obtained based on the linearized model. Experimental results verify the effectiveness of the proposed method.