• Korean Journal of Optics and Photonics
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• v.33 no.2
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• pp.67-73
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• 2022

In a head-mounted display (HMD) for virtual-reality applications, a narrow viewing angle is preferred to the usual, wide viewing angle because the HMD is positioned close in front of the user's eyes, and the display position is fixed. In this paper, we propose a new back-light unit (BLU) for implementing a narrow viewing angle, which is suitable for a HMD. By optimizing the scattering patterns in the light-guide-plate and inverse-prism structures, the viewing angle and correlations between structural parameters in the BLU components are analyzed with ray-tracing simulations. As a result, a double-angle inverse-prism structure incorporating the scattering patterns of a light-guide plate is chosen, which results in a 14% increase in center luminance, a 16% decrease in the vertical viewing angle, and a light efficiency of up to 70%, compared to a conventional BLU. Thus, the new BLU system is expected to be applied in a high-efficiency liquid crystal display.

• Journal of Space Technology and Applications
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• v.2 no.1
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• pp.52-65
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• 2022

Korea is near close the success on the indigenous launch vehicle KSLV-2 after the second test launch during the second half of 2022, and the satellite development has been already in the level of advanced country. After the such mature of satellite and launch vehicle technologies, Korea's space development main theme should be 'Space Exploration and Space Application', and paradigm should be changed from 'Hardware' to 'Scientific/Technological Mission', from 'Unmanned' to 'Manned'. Korea's prime space strategy should be the direction of expansion of space industry, creation of employment and secure the key technologies, improvement of convenience and safety of people. For the purpose it is necessary to start 'Manned Space Development' such that participation to 'Artemis and Gateway Program' in 20s' and manned Mars exploration in 30s' which would be carried out by means of global international cooperation, and which could be a good opportunity to explore the new area of space development and upgrade national technology capability. Taking advantage of this opportunity, it is required for Korea to join the international programs through developing indigenous challenging, sustainable Korean mission and hardware. Also selection of the 2^nd Korean Astronaut could draw national attention, especially could give dreams to young generation. Participation to the Artemis program could be the opportunity of entering the major space fairing nation and boosting up national pride. In this study we survey and analyze the Artemis Program in detail, and in conclusion we suggest the strategy of Korea's participation to the Artemis Program.

• Journal of the Society of Disaster Information
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• v.18 no.1
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• pp.228-240
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• 2022

A comprehensive safety management system will be required in accordance with the implementation of the Major Disaster Punishment Act for close-up safety management of construction sites. Safety management level evaluation management requires a comprehensive relationship between safety management under the Construction Technology Promotion Act and health and health management system under the Industrial Safety and Health Act. Purpose: Safety under the Serious Accidents Punishment Act. The ultimate goal is to study the comprehensive analysis and relationship of health management and to improve the safety evaluation level of health and health management. Methods: The feasibility of the questionnaire was confirmed through the second Delphi analysis of construction site experts and safety managers, and the regression coefficient and path analysis of potential variants in safety management, safety management, health management and safety inspection were confirmed. Result and Conclusion: In the structural model, the regression coefficient (89%) from safety management, health system, and safety management to safety inspection execution and lambda values of appropriate observation variables were confirmed. In the path analysis, the total effect (.809) was confirmed by mediating health hygiene in the relationship between health plan establishment adequacy and post-inspection management, and the path coefficient (.82) of temporary structure safety was confirmed.

• Journal of Korean Library and Information Science Society
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• v.52 no.4
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• pp.1-21
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• 2021

This study traced the origin and transformation of word library linked with archives in the ancient Near East, and Greece and Rome. First, the word library has two origins. One is derived from the Latin bibliothēkē from the ancient Greek βιβλιοθήκη. The first trace is Pollux's Onomasticon in the second half of the 2nd century, and if considered as a set of literature texts, it is Lipsius's De Bibliothecis Syntagma in 1602. The other was established as an library in the early 14th century after Latin libraria (or librarium) was translated into Old French librairie (or librarie). The word library was coined by Chaucer in 1374. Second, the clay tablet repository that existed in the ancient Near East is close to an archive, but the official name is unknown. However, the Ashurbanipal clay tablet archive is far from the principle of respect for original order and origins emphasized by the archivists, so it is not a royal archive, but a prototype of the royal library. And the official name of the Library of Alexandria was 'Βιβλιοθήκη της Αλεξάνδρειας', and then it was changed to 'ALEXANDRINA BYBLIOTHECE'. Third, In ancient Greece and Rome, archives and libraries were separated. Greece libraries were at the level of a small libraries attached to gymnasiums, and had few independent titles. The names of the Roman libraries often attached to the public baths were mixed with βιβλιοθήκη and Bibliotheca. Finally, the ancient library was succeeded to the cathedral bibliothek, and was transformed into 'bayt al-hikmah' in the Islamic Empire. In Japan, China, and Korea, Japanese-Chinese word library was accepted at the end of the 19th century, but there are many issues that require follow-up research.

• Korean Journal of Mineralogy and Petrology
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• v.35 no.4
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• pp.457-467
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• 2022

Electron bombardment to silicate glass during electron probe microanalysis (EPMA) causes outward migration of Na from the excitation volume and subsequent decrease in the measured X-ray count rates of Na. To acquire precise Na₂O content of silicate glass, one should use proper analytical technique to avoid or minimize Na migration effect or should correct for decreases in the measured Na X-ray counts. In this study, we analyzed 8 silicate glass standard samples using automated Time Dependent Intensity (TDI) correction method of Probe for EPMA software that can calculate zero-time intercept by extrapolating X-ray count changes over analysis time. We evaluated an accuracy of TDI correction for Na measurements of silicate glasses with EPMA at 15 kV acceleration voltage and 20 nA probe current electron beam, which is commonly utilized analytical condition for geological samples. Results show that Na loss can be avoided with 20 ㎛-sized large beam (<0.1 nA/㎛²), thus silicate glasses can be analyzed without TDI correction. When the beam size is smaller than 10 ㎛, Na loss results in large relative errors up to -55% of Na₂O values without correction. By applying TDI corrections, we can acquire Na₂O values close to the reference values with relative errors of ~ ±10%. Use of weighted linear-fit can reduce relative errors down to ±6%. Thus, quantitative analysis of silicate glasses with EPMA is required for TDI correction for alkali elements such as Na and K.

• Science of Emotion and Sensibility
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• v.25 no.2
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• pp.79-86
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• 2022

With external air pollution forcing many people indoors, new methods of facilitating healthier indoor life are necessary. This study, therefore, investigates the effects of indoor oxygen concentration and respiration methods on biosignals and cognitive ability. The study included twenty healthy subjects who inhaled air through a mask from a gas delivery system. All subjects were asked to perform three types of breathing (nasal, oral, and oral breathing with high oxygenation) and respond to cognitive stimuli (rest close eye, rest open eye, 1-back and 2-back working memory tasks). The changes in cognitive load according to respiration were analyzed by measuring response time, accuracy, and biosignals to stimuli. The result showed that, in all three respirations, heart rate significantly increased with the increase in cognitive load. Also, in oral respiration, the airway respiration rate significantly increased according to the increase in cognitive load. The change appeared to compensate for insufficient oxygen supply in oral respiration during cognitive activity. Conversely, there was no significant change in airway respiration rate during oral respiration with a high concentration oxygen supply as in nasal respiration. This result suggests that a high concentration oxygen supply might play a role in compensating for insufficient oxygen concentration or inefficient oxygen inhalation, such as oral respiration. Based on the results of this study, a follow-up study is necessary to determine the impact of changes in the autonomic nervous system, such as stress and emotions, to find out more precise and comprehensive effects of oxygen concentration and breathing type.

• The Journal of the Convergence on Culture Technology
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• v.8 no.5
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• pp.469-475
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• 2022

As the recent structure construction is constructed as a large-scale and deep underground excavation in close proximity to the building, the installation of retaining wall and supporters (Struts) has become complicated, and the number of supporters to avoid interference of the structural slab has increased. This construction process becomes a factor that causes an increase in construction joints of a structure, leakage and an increase in wall cracks. In addition, this reduced the durability and workability of the structure and led to an increase in the construction period. This study planned to dismantle the two struts simultaneously as a plan to reduce the construction joints, and corrected the earth pressure by assuming the reaction force value by the initial earth pressure and the measured data as the response ratio. After recalculating the corrected earth pressure through the iterative trial method, it was verified by numerical analysis that simultaneous disassembly of the two struts was possible. As a result of numerical analysis applying the final corrected earth pressure, the measured value for the design reaction force was found to be up to 197%. It was analyzed that this was due to the effect of grouting on the ground and some underestimation of the ground characteristics during design. Based on the result of calculating the corrected earth pressure in consideration of the response ratio performed in this study, it was proved analytically that the improvement of the brace dismantling process is possible. In addition, it was considered that the overall construction period could be shortened by reducing cracks due to leakage and improving workability by reducing construction joints. However, to apply the proposed method of this study, it is judged that sufficient estimations are necessary as there are differences in ground conditions, temporary facilities, and reinforcement methods for each site.

• Journal of Korea Entertainment Industry Association
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• v.13 no.2
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• pp.123-132
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• 2019

This paper analyzes the performances of actor Song Kang-Ho in the background of interdisciplinary and integrated film acting, using performance rather than acting as a general term. If the act is a concept limited to acting training or acting skills, performance is a broad concept that includes expressions, movements, and emotions. The performance on the screen can be explained in the context of film and can be extended to the social attitude of acting. In addition, I used the term screen in terms of representation rather than film referring to medium. Song Kang-Ho expressed the performances of various characters in more than 30 films. Although his facial expressions, gestures, and voices suitable for individual characters in various genres are represented in various ways, personality inherent in the actor Song Kang-Ho integrates persona with character. What drives it is the social attitude of screen performance. As a sign, acting is an ideological construct and foregrounds a character who describes a certain social and historical moment. Song Gang-Ho as actor, persona and character, who asserts the popularity, speaks to society and makes discourse. His comic performance is always confronting the tragedy of life, his face is the spirit of the times, and it expands into social meaning. The face of the close-up does not laugh at all, the gesture symbolized by the curved rear view is exaggerated disorderedly and disturbingly, and the voice using dialect accent does not follow the standard of the vocal.

• Journal of International Area Studies (JIAS)
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• v.12 no.4
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• pp.67-88
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• 2009

In April, 1995, ANC government was established in South Africa. The Black government set up Truth and Reconciliation Committee in November, 1995. The Committee investigated approximately 50,000 cases for 3years. Through this process, Black and White in SA could be united into one. Finally, the system of racial discrimination, lasting for about 300 years, was abolished. The Committee played a role as a social infra-structure, which was to perform and solidify democracy in SA. Reconciliation, agreement, Participation, equality, Communication, and Reformation of law system were practically implemented by the Committee. Many people evaluate TRC's activity, which had the reformative and democratic character of the object of investigation, investigative criterion, investigative process, and the approval of investigative result. But De Klerk evaluates that TRC retaliated the White with legal. J. Cronin evaluates that TRC transiently change democracy of the South Africa, and many other social movement groups had a negative view about TRC. But the Black and White in South Africa transformed 'discriminated society' into 'united one'. The Committee took the initiative in such a change. The Committee was not an organization needed for the policy, but the committee was the policy itself to change the former society to the new one. Now The ANC government was forwarding TRC's roles and functions to the truth and reconciliation bureau of the Justice Department for further action. The ANC government has to execute some policy for social reconciliation. Firstly, the government needs to build construction social and national system for making close investigation into the White's historical guilt. Secondly, it must be executed to TRC's recommendation pursuit social reform of social infra-structure in the South Africa. Thirdly, The government should execute policy for the Black's right as labors and social member. Lastly, the government must investigate still-remaining historic state violence and infringement of human right for social reconciliation.

• Clean Technology
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• v.15 no.4
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• pp.265-272
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• 2009

In this study the experiments on the static adsorption of benzene were carried out using activated carbon made from sewage sludge. The experiment was performed at 303.15 K, 318.15 K and 333.15 K under the pressure up to 7.999kPa. Isothermal adsorption curves were obtained using Langmuir isotherm, Freundlich isotherm and Toth isotherm for comparison. Based on fitting the adsorption quantity of Benzene (q), the isothermal adsorption curves obtained from Langmuir isotherm and Toth isotherm showed the higher accuracy. Although there was little difference in accuracy between result from Langmuir isotherm and that from Toth isotherm, the adsorption quantity of Benzene (q) was expressed in terms of Langmuir isotherm because less parameters were required for Langmuir isotherm than for Toth isotherm. Moreover SEM images of the activated carbon from sewage sludge and the commercial activated carbon were taken to observe the pore size development. The results showed that the perforation development of the commercial activated carbon (DARCO A.C., SPG-100 A.C.) was better than that of activated carbon from sewage sludge. Adsorption quantity of benzene on commercial activated carbon was confirmed to be higher than that on activated carbon from sewage sludge. However the maximum adsorption quantity of benzene on activated carbon from sewage sludge was close to that on SGP-100 A.C. at 303.15K. Therefore, we may conclude that it is feasible to commercialize the process to manufacturing activated carbon from sewage sludge.