• The Journal of the Convergence on Culture Technology
• /
• v.9 no.3
• /
• pp.415-423
• /
• 2023

The purpose of this study was to prepare basic data for improving school library information service by investigating the information usage behavior of specialized high school students. Preferred information sources for each situation requiring information and the level of solving information problems using information sources were investigated, and difference analysis was conducted by department and grade. As a result of the survey, the percentage of students who preferred Internet portal services, personal information sources (teachers, friends, parents), and social media was high, while the percentage of students who preferred traditional print information sources and mass media was very low. The average score of the information problem solving level was 3.55, and the problem solving level in the areas of employment and career/admission was relatively low. Preferred sources of information were similar regardless of grade and department, and the difference between departments in information problem solving level was not statistically significant, but the difference between grades was statistically significant. In addition, there is an academic contribution in this field that specific examples of youth information use behavior have been added. Based on the results of the study, librarians should make efforts to verify the reliability of Internet portal site information, improve and promote library information sources, and expand library use education. In future studies, it was suggested to develop customized information services.

• Economic and Environmental Geology
• /
• v.32 no.4
• /
• pp.323-337
• /
• 1999

Late Cretaceous to early Tertiary volcanic rocks in the Kyongsang basin exhibit high-K calc-alkaline characteristics, and originated from the magmatism related genetically to subduction of Kula-Pacific plate. They represent HFSE depletion and LlLE enrichment characteristics as shown by magmas related to subduction. Early studies on the depth of magma generation has been estimated as 180-230 km based on K-h relation should be reevaluated, because the depth of peridotite partial melting with 0.4 wt. % water is 80-120 km at subduction zone, and subducting slab in premature arc can melted even lower than 70 km. Moreover the increase of potassium contents depends on either contamination of crustal material and fluids of subducting slab or low degree of partial melting. If the inclination of subduction zone is 30 degrees and the depth to the Benioff zone is 180-230 km, the calculated distance between the volcanic zone and trench axis would be 310-400 km. It is unlikely because the distance between the Kyongsang basin and trench during late Cretaceous to early Tertiary is closer than this value and not comparable with generally-accepted models in subduction zone magmatism. $K_{55}$ of the volcanics in the Kyongsang basin is 0.3-2.3 wt.% and the average indicate that the depth ranges between 80-170 km on the diagram of Marsh, Carmichael (1974). Fractionation from garnet lherzolite, assumed the depth of 180-230km, is not consistent with the REE patterns of the volcanoes in the Kyongsang basin. Futhermore, the range of depth suggested by many workers, who studied magmatism related to subduction, imply shallower than this depth. Crustal thickness calculated by the content of CaO and $Na_2O$ is about 30 km and about 35 km, respectively. Paleo-crustal thickness during late Cretaceous to early Tertiary times in the Kyongsang basin inferred about 30 km calculated by La/Sm versus LaJYb data, which is also supported by many previous studies.

• Clean Technology
• /
• v.17 no.4
• /
• pp.306-313
• /
• 2011

Flux or solder is used in soldering process for manufacturing electronic parts such as printed circuit boards (PCB). After soldering process, residual flux and solder paste on the parts should be removed since their residuals could cause performance degradation or failure of parts due to their corrosion and electric leakage. Ozone depletion substances such as 1,1,1- trichloroethane (TCE) and HCFC-141b have widely been using for removal of residual flux and solder paste after soldering process In manufacturing of electronic parts until now. In this study, non-aqueous cleaning agents without flash point were developed and applied to industrial field for replacement of cleaning agents with ozone depletion. In order to develop non-aqueous cleaning agents without ethers, esters, fluoride- type solvents. And their physical properties and cleaning abilities were evaluated, and they were applied to industrial fields for cleaning of flux and solder on the PCB. And vacuum distillation apparatus were operated to determine their operating conditions and recycling yields for recycling of used cleaning agents formulated in this study. As a result of physical properties measurement of our formulated cleaning agents, they were expected to have good wetting and penetrating power since their surface tensions were relatively low as 18.0~20.4 dyne/$cm^2$ and their wetting indices are relatively large. And some cleaning agents holding fluoride-type solvents as their components did not have any flash point and they seemed to be safe in their handling and storage. The cleaning experimental results showed that some cleaning agents were better in their cleaning of flux and solder paste than 1,1,1-TCE and HCFC-141b. And industrial application results of the formulated cleaning agents for cleaning PCB indicated that they can be applicable to industry due to their good cleaning capability in comparison with HCFC-141b. The recycling experiments of the used formulated cleaning agents through a vacuum distillation apparatus also showed that their 91.9~97.5% could be recycled with its proper operating conditions.

• KOREAN JOURNAL OF PACKAGING SCIENCE & TECHNOLOGY
• /
• v.24 no.2
• /
• pp.65-71
• /
• 2018

Paper packs, glass bottles, metal cans, and plastic materials are classified according to packaging material recycling groups that are Extended Producer Responsibility (EPR). In the case of waste paper pack, the compressed cartons are dissociated to separate polyethylene films and other foreign substance, and then these are washed, pulverized and dried to produce toilet paper. Glass bottle for recycling is provided to the bottle manufacturers after the process of collecting the waste glass bottle, removing the foreign substance, sorting by color, crushing, raw materializing process. Waste glass recycling technology of Korea is largely manual, except for removal of metal components and low specific gravity materials. Metal can is classified into iron and aluminum cans through an automatic sorting machine, compressed, and reproduced as iron and aluminum through a blast furnace. In the case of composite plastic material, the selected compressed product is crushed and then recycled through melt molding and refined products are produced through solid fuel manufacturing steps through emulsification and compression molding through pyrolysis. In the recycling process of paper packs, glass bottles, metal cans, and plastic materials, the influx of recycled materials and other substances interferes with the recycling process and increases the recycling cost and time. Therefore, the government needs to improve the legal system which is necessary to use materials and structure that are easy to recycle from the design stage of products or packaging materials.

• Radiation Oncology Journal
• /
• v.17 no.1
• /
• pp.84-88
• /
• 1999

Purpose :To develop a method for verifying a treatment setup in stereotactic radiotherapy by ma- tching portal images to DRRs. Materials and Methods : Four pairs of orthogonal portal images of one patient immobilized by a thermoplastic mask frame for fractionated stereotactic radiotherapy were compared with DRRs. Portal images are obtained in AP (anteriorfposterior) and lateral directions with a target localizer box containing fiducial markers attached to a stereotactic frame. DRRs superimposed over a planned iso-center and fiducial markers are printed out on transparent films. And then, they were overlaid over onhogonal penal images by matching anatomical structures. From three different kind of objects (isgcenter, fiducial markers, anatomical structure) on DRRs and portal images, the displacement error between anatomical structure and isocenters (overall setup error), the displacement error between anatomical structure and fiducial markers (irnrnobiliBation error), and the displacement error between fiducial markers and isocenters (localization error) were measured. Results : Localization error were 1.5$\pm$0.3 mm (AP), 0.9$\pm$0.3 mm (lateral), and immobilization errors were 1.9$\pm$0.5 mm (AP), 1.9$\pm$0.4 mm (lateral). In addition, overall setup errors were 1.0$\pm$0.9 mm (AP), 1.3$\pm$0.4 mm (lateral). From these orthogonal displacement errors, maximum 3D displacement errors($\sqrt{(\DeltaAP)^{2}+(\DeltaLat)^{2}$)) were found to be 1.7$\pm$0.4 mm for localization, 2.0$\pm$0.6 mm for immobilization, and 2.3$\pm$0.7 mm for overall treatment setup. Conclusion : By comparing orthogonal portal images with DRRs, we find out that it is possible to verify treatment setup directly in stereotactic radiotherapy.

• Cartoon and Animation Studies
• /
• s.45
• /
• pp.321-343
• /
• 2016

The purpose of this thesis is to look through the political and social background of China preparing for a new era after getting out of the Communist Party of Mao Zedong, rapid inflow of the Western modernism and the avant-garde art arising in China with the focus of art works of Xu Bing, which contributed to the expansion of printmaking of China. Particularly, 85 New Wave Movement arose by young artists since 1985 and the China/Avant-Garde Exhibition held in Beijing in 1989 are the two important issues which reflect a new change from the traditional Chinese art. The artists of 85 New Wave Movement, who pursued a historical revolution and novelty, worked very actively by leading private exhibitions. Since the Cultural Revolution, the government owned the National Museum of Fine Art Beijing had exhibitions on a large scale displaying various visual arts such as performing art, installation, painting, sculpture but the Chinese government interrupted exhibitions two time due to bold performing art and unconcealed installation. Some artists were even taken to the police when performing art. Under these circumstances, Xu Bing, who majored printmaking, produced one of his major works, Books from the sky(1988), while he was working on various experiments focusing on the production process of printmaking and its repetitiveness. Xu Bing devised letters, carved them in trees and finally created approximately 2000 characters. Going further he displayed it as installation work, which means the developed characters go beyond a printed form, for audiences. This made him earn favorable reviews since it was a form of western art coupled with Chinese contents 'Chinese character'. After he received unfavorable reviews, however, he went to America leaving his last work in China, Ghost Pounding the Wall, in 1990, which was not able to exhibited. In those days, China society was going through a chaotic era thanks to the extinction of the Cultural Revolution and Deng Xiaoping's(1904-1997) reformation after the debacle of Tiananmen Massacre. This study looks into Xu Bing's artworks from his initial print works until he went to the US in 1991 and examines how he performed experiments utilizing reproductivity and plurality of prints tinged with Chinese traditional elements, and ultimately became one of the avant-garde artists representing the period.