• Journal of the Korean Applied Science and Technology
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• v.35 no.3
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• pp.757-767
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• 2018

In the propane dehydrogenation reaction proceeding at high temperature, the main cause of deactivation of the catalyst is coke deposition and sintering. In order to investigate the catalysts for reducing such inactivation, we have investigated the applicability of $MgAl_2O_4$ as a carrier for the catalytic dehydrogenation reaction. $MgAl_2O_4$ was prepared by Alcohthermal method at calcination temperature of 800, 900, $1000^{\circ}C$, and $Pt-Sn/MgAl_2O_4$ catalyst was prepared by supporting Pt and Sn by co-impregnation method. The reaction temperature was conducted at a high temperature of 650, $600^{\circ}C$ to confirm the thermal stability. As a result of the reaction experiment, it was confirmed that the conversion rate and yield of propane dehydrogenation reaction test were higher than that of the carrier-applied catalyst having a carrier calcination temperature of 900 and $1000^{\circ}C$, when the carrier-applied catalyst having a calcination temperature of $800^{\circ}C$ was used, It was found that the yield was higher than that of $Pt-Sn/{\theta}-Al_2O_3$ at $650^{\circ}C$. TGA, BET, XRD, CO-chemisorption, and SEM-EDS analyzes were performed for characterization. $MgAl_2O_4-800^{\circ}C$ was correlated with the relationship between good yield, Pt dispersion and low deactivation rate.

• Journal of Korean Society of Environmental Engineers
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• v.32 no.3
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• pp.264-270
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• 2010

Waste activated sludge from sewage treatment plants mainly consisted of flocs of bacterial cell, and thus hard to be stabilized anaerobically due to rigid cell walls. One of the pretreatment methods to overcome this barrier is the venturi cavitation system (VCS) adopting hydrodynamic cavitation. This research was conducted to investigate the effects of the pretreatment of waste activated sludge by VCS on the anaerobic digestibility. Depending on the pretreatment period with the VCS, methane production, COD removal and VS removal efficiency increased 41%~45%, 36.5%~43.1% and 18.4~24.1%, respectively, compared to the control case. The increase in methane production from digester was 3.3~4.2 times higher than the theoretical methane potential of the increased SCOD after the VCS pre-treatment. This suggests that the VCS pre-treatment not only increases SCOD but also improves the digestibility of solid fractions. The energy mass balance indicated that the energy consumed for sludge pre-treatment could be recovered by the increased methane production after pre-treatment, suggesting the high potential for field application.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.33 no.1 s.60
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• pp.29-32
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• 2007

We investigated new ingredients with real efficacy in both in vitro and in vivo all together. Especially we focused on the real improving effort in the clinical experiments. Because most products containing effective materials evaluated in vitro failed to show a real improving effect in the human with acne. We evaluated the well-known ingredients in a small scale clinical experiment with half-finished goods containing each ingredient. Among these products, product formulating SeleMix AN composed with germinating soy bean and magnolias bark extract remarkably improved acne and acne scar. Moreover skin redness caused by severe acne was improved. There was statistical significance between placebo and sample. Two hundred volunteers participated in our pilot study with written informed consent. After then we performed in vitro efficacy test this ingredient. SeleMix AN inhibited the growth of propionibacterium acnes at a concentration of 0.0125% and suppressed histamine release by 16.9%. Moreover human fibroblast cell activity was increased by 57% compared to control. Lastly, we performed a clinical study. Consisting of groups of 23 volunteers. Although the period of the test was in summer accelerating sebum secretion and recurring a high tate of acne, inflammation lesions were especially improved after applying product containing SeleMix AN for 4 weeks.

• Informatization Policy
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• v.22 no.4
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• pp.3-21
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• 2015

Since the 1990s, the notion of governance has been introduced as an alternative way of understanding the new trend of public administration. Then, it was followed by the emergence of the concept, e-governance (electronic governance) with the development of information and communication technologies. E-governance means an approach to understanding how to manage state affairs. It emphasizes the notion of governance where various actors (government-market-civil society, etc.) adjust and cooperate through mutual collaborative network, not a unilateral decision-making form of government, in order to solve common problems. It also carries the notion of 'electronic' in the sense that it operates on the basis of utilizing information and communication technology (ICT). This study systematically attempts to analyze research trends and methodologies of e-governance in major Korean journals and proceedings in the field of public administration and policy studies over the last 15 years. Some of the findings are worth noting: first, e-governance studies in Korea are in large measure concentrated on the government-centered perspective. Also, past studies tend to focus on problem-solving by suggesting policy alternatives. Past studies, thus, seem to pay relatively less attention to explanation of the phenomena through rigorous analysis. Under the circumstances, this review is expected to shed light on some of conceptual or methodological issues related e-governance studies, thus, to provide significant implications for future research of e-governance.

• Polymer(Korea)
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• v.37 no.3
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• pp.316-322
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• 2013

In this study, poly(ethylene terephthalate) (PET) was treated with fluorination and ultrasonic washing treatment for hydrophilic modification of PET film. We measured the change of surface modified PET film surface characteristics using contact angle, surface free energy, FE-SEM, AFM and XPS. After direct fluorination and ultrasonic washing treatment, the water contact angle was measured to be $10.81^{\circ}$, 85% reduction compared to the untreated PET film. Total surface free energy has been measured to be $42.25mNm^{-1}$, 650% increase compared to the untreated PET film. Also RMS roughness has been measured to be 1.965 nm, 348% increase compared to the untreated PET film. Hydrophilic functional group C-OH bond concentration has increased approximately 3 times. These results are attributed to the hydrophilic functional group and cavitation due to chemical etching. From this result, it was suggested that the fluorination-ultrasonic washing treatment method could be useful to make PET film surface hydrophilic.

• Journal of the Korean Chemical Society
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• v.31 no.3
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• pp.258-270
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• 1987

A series of new thorium nitrate complexes with crown ethers have been synthesized from the reaction of the hydrated thorium nitrate, with the appropriate crown ethers of different cavity sizes in various solvents such as methanol, ethanol, butanol, methylacetate, acetone, tetrahydrofuran and acetylacetone. CHN elemental analysis, ICPAS, thermal analysis and Karl-Fischer method have been used to characterize their compositions, and the spectroscopic methods of IR, UV, $^1H-NMR$, and X-ray diffraction have been employed to determine the structures and solvolysis phenomena of these complexes. and the electrical conductances were measured in DMSO, and water solvent. The solvolysis have been observed only in the complexes synthesized in acetylacetone solvent. In the solvated complexes of 15-crown-5 and 18-crown-6, the mole ratio of $Th^{4+}$: ligand : acetylacetone is found to be 1:1:1, but in the non-solvated complexes of 12-crown-4 and 15-crown-5, the mole ratios of Th:L are 1:2 and 2:3, respectively, and that in the complexes of both 18-crown-6 and dicyclohexano-18-crown-6 is 1:1. All complexes which were not solvated have shown $n{\to}{\sigma}^{\ast}$ electronic transitions of crown ether whereas complexes solvated have exhibited both $n{\to}{\sigma}^{\ast}$ of crown ether and $n{\to}{\pi}^{\ast}$ transitions of acac. The dissociation mole ratio of $Th^{4+}$ and nitrate ion is found to be 1:1 in aprotic solvent, and 1:4 in protic solvent like water.

• Korean Journal of Childcare and Education
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• v.12 no.1
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• pp.143-170
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• 2016

This paper organized a cooperative activity using character-related picture books for guiding children to cooperate as a part of an effort to present solutions against the increasing tendency of individualism and the de-communization phenomenon among serious social issues affecting children in modern society. This paper aims to help the children to build the proper caring thinking for others and understanding the self by applying those cooperative activities. The subjects were 50 children of 4 years old in K and S day care centers in city C. The data were analyzed by caring thinking tool using t-test. It also recognized change to children's caring thinking of play situation by way of video and observation journal. The results of the research found that the experimental group's caring thinking score was significantly higher than that of the control group. In accordance with the general analysis of the program results, it was verified that the cooperative activity's use of character-related picture books included caring thinking, understanding the self, and respecting others' emotionsin them. The results of this study can be used as basic data to develop an educational activity program for character development and help with the application of character-related picture books.

• Korean journal of communication and information
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• v.80
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• pp.167-192
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• 2016

This study examined the social trauma experienced by direct victims of accidents and each member of the society affected by grand-scale disasters based on the concepts of collective unconsciousness, archetype, and individuation from Jung's analytical psychology, and their experience of therapy through media. For this purpose, the survivors of the disaster of Sewol that occurred on April 16, 2014, family of the deceased, psychological professionals, and general volunteers were selected as the subjects for one-on-one in-depth interviews and focus group interviews. The findings can be summarized as follows: first, the subjects are suffering from different forms of social trauma such as seclusion and anxiety due to primary/secondary incidents, but there is possibility for them to overcome the social trauma as a social community. Second, the archetypes of life and death, mourning and remembrance are showing in the subjects' everyday lives. In particular, it was found that various archetypes are appearing symbolically through the craft activities in which the survivors are participating most actively. Third, the media therapy program for the victims of the Sewol has limitations in various aspects. However, the fact that the craft activities that are not bound by time and space are highly effective manifests that anyone can take advantage of trauma therapy through digital media that are easily found around them. Finally, this study is significant as it verified the possible individuation of social trauma and identified the limitations of media therapy to suggest its development directions.

• Journal of the Korea Convergence Society
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• v.8 no.5
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• pp.161-167
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• 2017

We have fabricated and characterized $32{\times}32$ photonic quantum ring (PQR) laser arrays uniformly operable with $0.98{\mu}A$ per ring at room temperature. The typical threshold current, threshold current density, and threshold voltage are 20 mA, $0.068A/cm^2$, and 1.38 V. The top surface emitting PQR array contains GaAs multiquantum well active regions and exhibits uniform characteristics for a chip of $1.65{\times}1.65mm^2$. The peak power wavelength is $858.8{\pm}0.35nm$, the relative intensity is $0.3{\pm}0.2$, and the linewidth is $0.2{\pm}0.07nm$. We also report the wavelength division multiplexing system experiment using angle-dependent blue shift characteristics of this laser array. This photonic quantum ring laser has angle-dependent multiple-wavelength radial emission characteristics over about 10 nm tuning range generated from array devices. The array exhibits a free space detection as far as 6 m with a function of the distance.

• Progress in Medical Physics
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• v.22 no.3
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• pp.155-162
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• 2011

The analog image based system consisted of a simulator and medical linear accelerator (LINAC) for radiotherapy was upgraded to digital medical image based system by exchanging the X-ray film with Computed Radiography (CR). With minimum equipments shift and similar treatment process, it was possible that the new digital image system was adapted by the users in short time. The film cassette and the film developer device were substituted with a CR cassette and a CR Reader, where the ViewBox was replaced with a small size PC and a monitor. The viewer software suitable for radiotherapy was developed to maximize the benefit of digital image, and as the result the convenience and the effectiveness was improved. It has two windows to display two different images in the same time and equipped various search capability, contouring, window leveling, image resizing, translation, rotation and registration functions. In order to avoid any discontinuance of the treatment while the transition to digital image, the film and the CR was used together for 1 week, and then the film developer was removed. Since then the CR System has been operated stably for 2 months, and the various requests from users have been reflected to improve the system.