• Proceedings of the KACD Conference
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• 2001.11a
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• pp.589.1-589
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• 2001

The aim of this study is to evaluate the effect of light intensity variation on the polymerization rate of composite resin using IB system(experimental equipment designed by Dr. IB Lee) by which real-time volumetric change of composite can be measured. Methods: Three commercial composites [Z100(Z1), AeliteFil(AF), SureFil(SF)] were photopolymerized with Variable Intensity Polymerizer unit (Bisco, U.S.A.) under the variable light intensity (75/150/225/300/375/450㎽$^2$) during 20sec.(omitted)

• Food Quality and Culture
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• v.2 no.1
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• pp.48-54
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• 2008

The purpose of this study was to evaluate the elementary students' knowledge, attitudes, and practice for food hygiene and safety. A self-administered questionnaire was developed and offered to 375 elementary school students throughout the Seoul region. The results of the survey were as follows: First, the knowledge, attitudes, and practice were not at satisfactory level. The scores of children's knowledge, attitudes, and practice were 67.42%, 3.83, and 3.81 out of 5 point scale, respectively. Second, knowledge, attitudes and practice levels were significantly different according to demographic characteristics. The lower grade-students had significantly higher scores for knowledge (p<.05), attitudes (p<.05) and practice (p<.01) than higher gradestudents, suggesting that food hygiene and safety education is more effective in younger students or that repeated education is needed for higher grade-students. Third, knowledge, attitudes and practice levels were significantly correlated each other. These results suggest that the education programs for food hygiene and safety should be developed for, as well as implemented in, lower elementary school grades.

• Proceedings of the Korean Society for Agricultural Machinery Conference
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• 2002.02a
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• pp.375-380
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• 2002

장 등(2001)에 의해 개발된 보급형 홍삼제조용 건조기를 이용하여 최고급 품질의 천지삼(H&EG)등급 홍삼의 수율을 15%이상으로 향상시킬 수 있는 공정 개발을 위한 실험을 수행한 결과, 1차 건조시 최적의 상대습도 조건은 60-70%인 것으로 나타났고, 초음파 속도 330-360m/s를 가지는 원료수삼이 홍삼으로 제조된 후 천지삼 수율이 높았으며 내공과 내백도 적게 나타났다. 한편 저장기간별로 우수 홍삼의 제조결과를 보면 최고급 품질의 홍삼제조를 위해서는 수확 후 3일 이내에 제조작업을 수행하는 것이 적절할 것으로 판단되었다. 한편 본 연구에서 개발된 최고급품질의 홍삼제조공정의 천지삼 수율측정을 위해 실험을 수행한 결과 천지삼의 평균수율이 18.8%나타났다. 이 결과를 통계분석한 결과에 의하면, 95%의 신뢰를 가지는 수율구간은 14.1%-23.7%로 나타났다. 또한 상기 결과를 비모수 X$^2$검증한 결과 모집단을 대표할 수 있는 것으로 나타났다. 그러므로 본 연구과제에 의해 개발된 최고급 품질의 홍삼제조공정기술은 성공적으로 개발된 것으로 판단되었다.

• KIISE Transactions on Computing Practices
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• v.22 no.8
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• pp.375-380
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• 2016

The proliferation of online social networking services (OSNSs) and smartphones has enabled people to easily make friends with a large number of users in the online communities, and interact with each other. This leads to an increase in the usage rate of OSNSs. However, individuals who have immersed into their digital lives, prioritizing the virtual world against the real one, become more and more isolated in the physical world. Thus, their socialization processes that are undertaken only through lots of face-to-face interactions and trial-and-errors are apt to be neglected via 'Add Friend' kind of functions in OSNSs. In this paper, we present a friend recommendation system based on the on/off-line contextual information for the OSNS users to have more serendipitous offline interactions. In order to accomplish this, we modeled both offline information (i.e., place visit history) collected from a user's smartphone on a 3D tensor, and online social data (i.e., friend relationships) from Facebook on a matrix. We then recommended like-minded people and encouraged their offline interactions. We evaluated the users' satisfaction based on a real-world dataset collected from 43 users (12 on-campus users and 31 users randomly selected from Facebook friends of on-campus users).

• Journal of the Society of Cosmetic Scientists of Korea
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• v.41 no.4
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• pp.375-382
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• 2015

Ginsenosides (ginseng saponin) as the one of important pharmaceutical compounds of ginseng and is responsible for the pharmacological and biological activities. These ginsenoside produces diverse small molecules ginsenoside which have more pharmacological activities including anti-wrinkle, anti-cancer and anti-oxidant effects. In the present study, we isolated bacteria using esculin agar, to produce ${\beta}$-glucosidase, and we focused on the bio-transformation of ginsenoside. Phylogenetic tree analysis was performed by comparing the 16S rRNA sequences; we identified the strain as Stenotrophomonas rhizopilae strain GFC09. In order to determine the optimal conditions for enzyme activity, the crude enzyme was incubated with 1 mM ginsenoside $Rb_1$. Bioconversion of ginsenoside $Rb_1$ were analyzed using TLC and HPLC. The crude enzyme hydrolyzed the ginsenoside $Rb_1$ along the following pathway: LB: $Rb_1{\rightarrow}Rd{\rightarrow}F_2$ into compound K, TSB: $Rb_1{\rightarrow}Rd{\rightarrow}F_2$. The structure of the hydrolyzed metabolites were identified by NMR. The activity screening tests showed that the conversion product induced the production of type I procollagen in a dose-dependent manner. These results suggested that hydrolyzed ginseng product containing the ginsenoside $F_2$ and compound K could be useful as an active ingredient for wrinkle-care cosmetics.

• Journal of computational fluids engineering
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• v.20 no.3
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• pp.62-69
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• 2015

Pressure change inside cabin as well as in tunnel has been calculated to assess the passenger pressure comfort of high-speed train. $C-STA^{TM}$, a CFD program based on axi-symmetric Navier-Stokes equation and Roe's FDS has been used to simulate the pressure change in tunnel during a high-speed train passing through it. To present the relative motion between the train and the tunnel, a modified patched grid scheme based on the structured grid system has been employed. The simulation program has been validated by comparing the simulation results with field measurements. Extensive parametric study has been conducted for various train speed, tunnel cross-sectional area and tunnel length to the pressure change in cabin. KTX-Sancheon(KTX2) high-speed train has been chosen for simulation and the train speed have been varied from 200 km/h to 375 km/h. The tunnel length has been varied from 300 m to 7.5 km and tunnel area from $50m^2$ to $120m^2$. Total 504 simulations have been conducted varying the parameters. Based on the database produced from the parametric simulations, minimum tunnel cross-sectional area has been surveyed for various train speeds based on Korean regulation on pressure change in cabin.

• Proceedings of the KSRS Conference
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• 2008.10a
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• pp.375-377
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• 2008

The KOMPSAT2 Terminal Polar Station was recently installed at near North Pole, Tromso, and Toulouse. The K2PS consists of one receiving station and two processing sites. The receiving station has been installed at SvalSat ($N78^{\circ}$, $E15^{\circ}$ ), and the two receiving sites have been installed at KSAT (Kongsberg Satellite Service AS), Tromso, Norway ($N69^{\circ}$ ,$E18^{\circ}$ ) and SISA, Toulouse, France ($N43^{\circ}$ ,$E1^{\circ}$ ). The products ofK2PS system can be classified to two categories: Level 1R product and Level 1G product. The Level 1R product is radiometric corrected product with RPC (Rational Polynomial Coefficients) and the Level 1G product is geometric corrected product with POD (Precise Orbit Data) and PAD (Precise Attitude Data) data based on Level 1R product. To meet a SISA (Spot Image SA)'s requirement, K2PS system has high performance product producing capability. This paper describes overall K2PS systems' production generation flow and the mass production test result of K2PS systems.

• Korean Journal of Poultry Science
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• v.41 no.1
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• pp.39-44
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• 2014

The goal of this study was to evaluate the growth performance of crossbred strains using Korean native chicken (KNC). The data were collected from 2012 through 2013 at Poultry Science Division, National Institute of Animal Science, Korea. The number of chicks analyzed in this study was 375. Crossbred were (A) $R{\times}S$, (B) $D{\times}H$, (C) $D{\times}S$, (D) $C{\times}Y$ and (E) $Y{\times}H$. The fertility rates of strains were 94.9% in crossbred A, 91.9% in crossbred B, 91.8% in crossbred C, 89.7% in crossbred D and 93.8% in crossbred E, respectively. The fertility was highest in crossbred A, but crossbred C showed the lowest (p<0.05) based on the hatchability. The crossbreds B and C exhibited a superior performance on body weight gains during growing stages but crossbred D showed the lowest (p<0.05). The feed intake was to the pattern of body weight. The feed intake of crossbred D was significantly lower than other crossbreds. Also, feed conversion ratio of crossbred D showed the lowest (p<0.05). Egg production ratio of crossbred D was significantly higher compared to the other crossbreds. These results suggest that the development of new crossbreds of commercial Korean Native Chickens should be required for better performance.

• Horticultural Science & Technology
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• v.31 no.1
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• pp.50-55
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• 2013

The objective of this research was to investigate the impact of Ca fertilizer on the growth of mother plants, physiological disorders, and occurrence of daughter plants in propagation of 'Seolhyang' strawberry through plastic bag cultivation. To achieve this, chemicals of 1.125 mM $Ca(OH)_2$, 0.375 mM $MgCl_2$, 1.250 mM KCl were blended and designated to combined fertilizer (CF). Then, the effect was compared to the treatment of no Ca application (control) and a commercial fertilizer, CalMag (13-0-1.9-16-6:N-$P_2O_5$-$K_2O$-CaO-MgO), when those were applied every two weeks with controlled electrical conductivity (EC) of solution such as 0.6 or 1.0 $dS{\cdot}m^{-1}$. The number of plants showing Ca deficiency symptoms was the highest in control treatment, but those decreased significantly in CF or CalMag treatments. The differences between CF and CalMag in appearance of Ca deficient plants were not significant when two fertilizers were applied with same EC. The fresh and dry weights of mother plants were the greater in the treatments of CF or CalMag than those of control treatment. The treatments of 1.0 $dS{\cdot}m^{-1}$ of CF or CalMag were more effective than those of 0.6 $dS{\cdot}m^{-1}$ on the fresh and dry weight of the mother plants. The runner lengths in the treatment of 1.0 $dS{\cdot}m^{-1}$ of CF were the longest among the all treatments tested. The treatments of 1.0 $dS{\cdot}m^{-1}$ were more effective than those of 0.6 $dS{\cdot}m^{-1}$ of CF or CalMag in lengths and fresh and dry weight of runners. The fresh and dry weights of daughter plants were heavier in the treatments of CF than those of CalMag. Based on the above results, we concluded that the Ca deficiency in raising 'Seolhyang' strawberry can be lessened by the application of Ca containing fertilizers, but combined application of Ca, K and Mg was more effective than that of Ca alone for seedling production.

• Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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• 2004.05a
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• pp.370-375
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• 2004

Fatigue tests were carried out to find the fatigue characteristics in the super-long life range by using a cantilever type rotational bending fatigue test machine. Three kinds of specimen in bearing steels with the quenched and tempered in air (A and B, B: shot peened after heal treatment) and under vacuum conditions(C:non-shot peened)were tested in this study. S-N curves obtained from fatigue tests of C specimen tend to come dawn again in the super-long life range due to fish-eye type cracking, while most of A and B specimens fractured by surface defects such as scratches and slip lines. This duplex S-N behavior for the high strength steels have to be reviewed by the change of fracture modes.