• Proceedings of the Korean Institute of Information and Commucation Sciences Conference
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• 2021.10a
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• pp.673-675
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• 2021

Biometric technology is a next-generation information security technology that provides reliability and convenience. As a core technology in the post-corona era, then on-contact biometric access control system is capable of non-face-to-face and automated technology, and is active not only in Korea but also in overseas markets such as the United States, Europe, and the Middle East. There are precautions that must be taken to reflect requirements such as cooperation between companies and approval of the US Food and Drug Admin is tration in developing IoT-based smart device customized sensors and securing H/W systems.

• Journal of the Microelectronics and Packaging Society
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• v.29 no.4
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• pp.1-8
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• 2022

High-density packaging technologies, including Through-Si-Via (TSV) technologies, are considered important in many fields such as IoT (internet of things), 6G/5G (generation) communication, and high-performance computing (HPC). Achieving high integration in two dimensional packaging has confronted with physical limitations, and hence various studies have been performed for the three-dimensional (3D) packaging technologies. In this review, we described about the causes and effects of scallop formation in TSV, the scallop-free etching technique for creating smooth sidewalls, Cu pillar and Cu-SiO₂ hybrid bonding in TSV. These technologies are expected to have effects on the formation of high-quality TSVs and the development of 3D packaging technologies.

• Journal of Ocean Engineering and Technology
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• v.2 no.1
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• pp.176-182
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• 1988

The exergy analysis on the heat storage performance of the senible heat storage unit which consists of the heat storage material in the concentric annulus and the hot fluid flowing through the inner tube is performed. Heat transfer characteristics which are necessary for the performance of the exergy analysis is obtained from the energy balance equations and the second law of thermodynamics. As the index of heat storage performance, the exergy lossnumber $N_{s}$, and exergy storage ratio from the concepts of the second law of thermodynamics are defined. Results are ovtained for the grometry of the storage unit, the Biot number Bi, ambient temperature $T_{o}$ as parameters. From these results the exergy storage ratio can be considered as the efficiency of the hat storage unit and is introduced as a guide to design.

• Journal of the Korea Organic Resources Recycling Association
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• v.10 no.1
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• pp.75-86
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• 2002

This study was performed to investigate situation of livestock manure generated from Kangwon-do and to evaluate its composting probability. The scale of livesrock-farming is bigger and bigger in Korea. Regulation based on the heads of livestock is slightly different from that based on livestock-farming household. So it is needed ro evaluate regulations for livestock head and livestock-farming household. Composting and liquid fertilization were thought to be appropriate technologies to the trearment of Korean cattle and pig manures, respectively. Generation quantity of pig manure was the greatest among pig, Korean cattle, cow and chicken manures. Pig manure generated the greatest amounts of BOD in Kangwon-do. Pig manure contained nitrogen, Korean cattle manure contained $K_2O$, and chicken and pig manures contained $P_2O_5$ in great amount. Alternative ratio of livestock manure to crops-fertilizer was 51% for nitrogen, 38% for $K_2O$, and 34% for $P_2O_5$.

• Korean Journal of Human Ecology
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• v.13 no.6
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• pp.967-983
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• 2004

The purpose of this study is to review Hanliu phenomenon, a kind of social and cultural phenomenon, in China and to analyze its effects on the fashion style of new young generation of China. In this study, Hanliu phenomenon means the enthusiasm of Asian people for Korean mass culture including Korean dramas, pop songs, and fashions from late 1990s. This research adopts two kinds of methods for analyzing the phenomenon: qualitative and quantitative research methods. As a qualitative research method, we analyzed it with several sources of documentaries and audio-visual materials: articles from newspapers and magazines, special TV reports, and documentary movie files from Internet. As a quantitative research method, we surveyed approximately 100 female students of Beijing university and asked how they feel Korean culture and fashions. The Hanliu phenomenon led to the popularity of Korean products as well as general culture of Korea. Also, it influenced Chinese young generation so much that Korean fashion has become prevailing. Such influence on the street fashion of Chinese youths can be summarized in three factors as follows: First, Korean entertainers' fashion is widely imitated. For example, H.O.T-like hairstyles, hip-hop styles, large heel shoes with boots-cut pants, and long-curled permanent hairstyles have been on among Chinese youths. Second, the preference for Korean fashion products has highly increased. The number of stores dealing with Korean fashion products has increased. Even the 'Kim Hee Seen,' a fashion brand named after a famous Korean actress, was introduced. Finally, Korean culture and products have widely been imitated in China as much as the increasing popularity of Korean fashion products. This study reveals that Hanliu phenomenon is widespread in China, and Chinese youths are largely affected by the fashion styles of Korean entertainers. Also, Korean fashion products are largely imitated and benchmarked in China. Hanliu phenomenon is a big chance to approach the fashion market of China, the largest buying power in the world. To make inroads into the Chinese fashion market, we suggest that we need to have our own brand and to make the most of culture, stars, and Internet in marketing. Also, we need a well-planned strategy for a success in the Chinese fashion market.

• Korean journal of applied entomology
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• v.36 no.1
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• pp.43-47
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• 1997

This study was carried out in the laboratory to clarify effects of different temperature of Protopulvinaria mangiferae(Green) on development, survivorship and reproduction. Developmental period of the mango shieldscale from crawlers to preoviposition adult decreased as temperature increased. The threshold temperature andthermal constants for the development of one generation were 11.7"C and 1000.0 day-degrees, respectively. At25$^{\circ}$C and 30$^{\circ}$C, survival rate from egg to preoviposition adult were 82% and 6096, respectively. Hatchability ofeggs was more than 99% at both condition. The reproductive period overaged 50 days(2SnC) and 33 days(30$^{\circ}$C). After mature adult began to reporduce, and more than 50% of the crawlers emerged during the firsthalf of their life time. The net reproduction rate per generation(R), mean length of a generation0 and intrinsicrate of natural increase(r, ) were higher at 25$^{\circ}$C than at 30"C, and the values measured at 25$^{\circ}$C were 132.6, 76.2 and 0.064/female/day, respectively.

• Publications of The Korean Astronomical Society
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• v.27 no.4
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• pp.117-122
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• 2012

The interstellar dust grains are formed and supplied to interstellar space from asymptotic giant branch (AGB) stars or supernova remnants, and become constituents of the star- and planet-formation processes that lead to the next generation of stars. Both a qualitative, and a compositional study of this cycle are essential to understanding the origin of the pre-solar grains, the missing sources of the interstellar material, and the chemical evolution of our Galaxy. The AKARI/MIR all-sky survey was performed with two mid-infrared photometric bands centered at 9 and $18{\mu}m$. These data have advantages in detecting carbonaceous and silicate circumstellar dust of AGB stars, and the interstellar polycyclic aromatic hydrocarbons separately from large grains of amorphous silicate. By using the AKARI/MIR All-Sky point source catalogue, we surveyed C-rich and O-rich AGB stars in our Galaxy, which are the dominant suppliers of carbonaceous and silicate grains, respectively. The C-rich stars are uniformly distributed across the Galactic disk, whereas O-rich stars are concentrated toward the Galactic center, following the metallicity gradient of the interstellar medium, and are presumably affected by the environment of their birth place. We will compare the distributions of the dust suppliers with the distributions of the interstellar grains themselves by using the AKARI/MIR All-Sky diffuse maps. To enable discussions on the faint diffuse interstellar radiation, we are developing an accurate AKARI/MIR All-Sky diffuse map by correcting artifacts such as the ionising radiation effects, scattered light from the moon, and stray light from bright sources.

• Journal of Ginseng Research
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• v.48 no.2
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• pp.211-219
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• 2024

Background: Recently, plant-derived exosome-like nanoparticles (PDENs) have been isolated, and active research was focusing on understanding their properties and functions. In this study, the characteristics and molecular properties of ginseng root-derived exosome-like nanoparticles (GrDENs) were examined in terms of skin protection. Methods: HPLC-MS protocols were used to analyze the ginsenoside contents in GrDENs. To investigate the beneficial effect of GrDENs on skin, HaCaT cells were pre-treated with GrDENs (0-2 × 10⁹ particles/mL), and followed by UVB irradiation or H₂O₂ exposure. In addition, the antioxidant activity of GrDENs was measured using a fluorescence microscope or flow cytometry. Finally, molecular mechanisms were examined with immunoblotting analysis. Results: GrDENs contained detectable levels of ginsenosides (Re, Rg1, Rb1, Rf, Rg2 (S), Gyp17, Rd, C-Mc1, C-O, and F2). In UVB-irradiated HaCaT cells, GrDENs protected cells from death and reduced ROS production. GrDENs downregulated the mRNA expression of proapoptotic genes, including BAX, caspase-1, -3, -6, -7, and -8 and the ratio of cleaved caspase-8, -9, and -3 in a dose-dependent manner. In addition, GrDENs reduced the mRNA levels of aging-related genes (MMP2 and 3), proinflammatory genes (COX-2 and IL-6), and cellular senescence biomarker p21, possibly by suppressing activator protein-1 signaling. Conclusions: This study demonstrates the protective effects of GrDENs against skin damage caused by UV and oxidative stress, providing new insights into beneficial uses of ginseng. In particular, our results suggest GrDENs as a potential active ingredient in cosmeceuticals to promote skin health.

• The Transactions of the Korean Institute of Electrical Engineers C
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• v.49 no.3
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• pp.155-160
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• 2000

The piezoelectric properties and the doping effect for$0.95Pb(Zr_xTi_{1-x})O_3+0.05Pb(Mn1/3Nb2/3)O_3$ compositions were studied. Also, the heat generation and the change of electromechanical characteristics, the important problem in practical usage, were investigated under high electric field driving. As a experiment results under low electric field, the values of kp and $\varepsilon33T$ were maximized, but Qm was minimized(Kp=0.57, Qm=1550) in the composition of x=0.51. In order to increase the values of Qm $Nb_2O_5$ was used as a dopant. As the result of that, the grain size was suppressed and the uniformity of grain was improved. Also, the values of kp decreased, and the values of Qm increased with doping concentration of $Nb_2O_5$. As a experiment results under high electric field driving, when vibration velocity was lower than 0.6[m/s], the temperature increase was $20[^{\circ}C]$, and the change ratio of mechanical quality factor was less than 10[%]. So, its electromechanical characteristics was very stable. Conclusively, piezoelectric ceramic composition investigated at this paper is suitable for application to high power piezoelectric devices.

• Journal of Sasang Constitutional Medicine
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• v.13 no.1
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• pp.51-60
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• 2001

Effects of Taeumjowetang on Lipid Peroxidation by Free Radicals and Oxidative Damage of Hepatocytes by tert-Butyl Hydroperoxide. 1. Purpose The present study was carried out to evaluate the antioxidant effects of Taeumjowetang in vitro. 2. Methods In this study, antioxidant effects of TJT on lipid peroxidation were determined according to the method of TBA. (Abbreviation) TJT : Taeumjowetang, TBA : 2-thiobarbituric acid. 3. Results : 1) TJT inhibited markedly peroxidation of linoleic acid during the autoxidation. 2) TJT inhibited lipid peroxidation induced by hydroxyl radical derived from H2O2-Fe2+ in rat liver homogenate. 3) TJT showed 66% scavenging effect on DPPH radical. 4) TJT exhibited a 25% inhibitory effect on superoxide generation from xanthine-xan thine oxidase system. 5) To investigate the antioxidative effects of TJT on the hepatocytes, cultured normal rat liver cells(Ac2F) were prepared and incubated with or without TJT. After 16~18hr, cells placed in DMEM medium without serum, and then incubated with 1mM t-BHP for 2hr. Viable cells were detected by MTT assay. In this test, TJT protected the cell death induced by t-BHP and significantly increased cell viability in the normal rat liver cell. (Abbreviation) DPPH : ${\alpha},{\alpha}$-diphenyl-${\beta}$-picryl hydrazyl, DMEM : Dulbecco's Modified Eagle Medium, t-BHP : terr-butyl hydroperoxide, 4. Conclusion These results suggested that TJT might play a protective role in lipid peroxidation by free radicals.