• Korean Journal of Optics and Photonics
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• v.21 no.2
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• pp.82-88
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• 2010

Photopolymer is a material for recording three dimensional holograms containing photo information. Photopolymer has been found to be a proper material due to many advantages such as high DE value, easy processing, and low price. Compositions of PVA, monomer, initiater and photosensitizer were determined by previous experiments and the compositions of $SeO_2$ and $TiO_2$ were considered as variable to find out the effects of $TiO_2$ on DE. The DE values were constant for the varying compositions of $TiO_2$ (0.1 mg~1.0 mg). In other words, $TiO_2$ is not directly effective on the DE values. Composition change experiments from $SeO_2$ 0.1 mg, $TiO_2$ 0.9 mg to $SeO_2$ 0.9 mg, $TiO_2$ 0.1 showed a maximum DE value of 73.75% at a component of $SeO_2$ 0.8 mg, $TiO_2$ 0.2 mg. It seemed that regardless of the amount of $TiO_2$, increasing the amount of $SeO_2$ gently increases DE`s. If nano particles are heavily added, transparent films could not be made due to the separation of particles by the solubility decrease. Photopolymer films could be made with high DE values for an extensive angle range if $TiO_2$ additions were kept minimum and $SeO_2$ additions were kept maximum.

• Korean Journal of Soil Science and Fertilizer
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• v.44 no.6
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• pp.1112-1117
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• 2011

This study was conducted to recommend nitrogen (N) top dressing based on soil nitrate content for leaf perilla under forcing culture in Gumsan-gun and Milyang-si. Experimental design was the randomized complete block design for five N fertilization levels and conventional fertilization. Dry weight, nitrogen uptake, and the node number of leaf perilla were measured and soil nitrate contents were analyzed monthly. The amount of nitrogen uptake for growth of a node with two leaves was $2.2kg\;10a^{-1}$ for Gumsan site and $3.5kg\;10a^{-1}$ for Milyang site. Lower level of soil nitrate N concentration for standard N fertilization was determined as $10mg\;kg^{-1}$ for both sites. Soil depth, bulk density, utilization rate of soil nitrate N, and the amount of N uptake for growth of a node with two leaves were considered for calculation of upper level of soil nitrate N concentration. The upper levels of soil nitrate N concentration for no N fertilization were determined as $30mg\;kg^{-1}$ for Gumsan site and as $40mg\;kg^{-1}$ for Milyang site. Consequently the recommendation equations for the N top dressing were Y=-0.157X+4.71 for Gumsan site and Y=-0.1667X+6.6667 for Milyang site.

• The korean journal of orthodontics
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• v.27 no.5 s.64
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• pp.853-864
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• 1997

The evaluation of growth potency can be done with many physiologic indicators. It has been well known that skeletal maturity has a close relation with both sexual maturity and somatic maturity, but the correlation between skeletal maturity and dental maturity was believed to be less certain. But, recent studies show that specific teeth, including lower canines, present close correlations with skeletal maturity. So, in this study, we studied hand-wrist X-ray films and orthopantomograms of 387 Korean boys and girls aged from 7 to 15; the purpose was to determine skeletal and dental maturity, and to find out a new method to estimate individual skeletal maturity using multiple-regression model, without the help of hand-wrist X-ray film. As a result of this study, followings were observed. 1. The following multiple-regression model can estimate skeletal maturity index (SMI) with 84% of accuracy, and regression coefficient of chronologic age, sex and lower canine show statistical significance. SMI = 0.60 x chronologic age - 1.67 x sex$^{**}$ + 0.88 x lower canine$^{*}$ - 0.05 x lower 2nd molar$^{*}$ - 10.3 $^{*}$ : mean age corresponding each developing stage, $^{**}$ : male=1, femal=0 2. The following multiple-regression model can estimate skeletal age with 87% of accuracy, and regression coefficient of chronologic age, sex and lower canine show statistical significance. Skeletal age = 0.75 x chronologic age - 0.55 x sex$^{**}$ + 0.71 x lower canine$^{*}$ - 0.09 x lower 2nd molar* -5.77 $^{*}$ : mean age corresponding each developing stage, $^{**}$ : male=1, femal=0

• Korean Journal of Environmental Agriculture
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• v.36 no.3
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• pp.169-174
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• 2017

BACKGROUND:Kiwifruit growers build their vineyards using many windbreaks to protect their kiwifruit vines from defoliation injury by strong winds such as typhoon. In this study, we have compared fruit quality, budbreak rate and floral bud as affected by windbreaks. And also we surveyed several microclimate indices of kiwifruit orchard depending on the covering materials of arch-type windbreaks. METHODS AND RESULTS: Five different windbreak materials including polyethylene film (PE), blue- and white-colored nets were tested in pipe-framed archtype kiwifruit vineyards as the covering materials. Photosynthetically active radiation (PAR), annual mean temperature (AMT) and chill unit (CU) as well as fruit quality were compared among the covering materials. In all treatments, annual PAR was more than $400{\mu}mol\;m^{-2}s^{-1}$, in which kiwifruit leaf could reach its maximum photosynthesis, since the leaves were emerged. Annual mean temperature was greater in 0.1 mm-PE covering as much as $1-2^{\circ}C$ than other windbreaks. In CU calculated by three different models, all windbreaks showed more than 1400 CU that is fully fulfilled CU for kiwifruit rest completion. There were no difference in budbreak rate among the covering materials. Fruit weight was heavier in 0.1 mm-PE and white-net (4 mm) than other windbreaks. CONCLUSION: Regardless of the windbreak materials, the PAR quantity was enough for kiwifruit photosynthesis. And CU for kiwifruit rest completion was fully achieved in all treatments. However, with respect to fruit weight, quantity of PAR, and AMT, etc., It is highly recommended for kiwifruit growers to choose 0.1 mm-PE and white-net (4 mm) as for their windbreaks materials.

• Journal of Bio-Environment Control
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• v.25 no.2
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• pp.89-94
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• 2016

This study was conducted to determine the optimum nutrient solution, pH, irrigation interval, light intensity and planting density to growth of common ice plant (Mesembryanthemum crystallinum L.) in a closed-type plant production system. Three-band radiation type fluorescent lamps with a 12-h photoperiod were used. Nutrient film technique systems with three layers were used for the plant growth system. Environmental conditions, such as air temperature, relative humidity and $CO_2$ concentration were controlled by an ON/OFF operation. Treatments were comparison of the nutrient solution of Horticultural Experiment Station in Japan (NHES) and the nutrient solution of Jeju National University (NJNU), pH 6.0 and 7.0, irrigation interval 5 min and 10 min, light intensity 90 and $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$, and within-row spacing 10 cm, 15 cm, 20 cm and 25 cm with between-row spacing 15 cm. Optimum macronutrients were composed N 7.65, P 0.65, K 4.0, Ca 1.6 and Mg $1.0mM{\cdot}L^{-1}$. There were no significant interactions between pH 6.0 and 7.0 about shoot fresh weight and shoot dry weight of common ice plant. Irrigation interval 5 min and 10 min was also the same result. Shoot fresh weight and shoot dry weight were highest at $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$. Shoot fresh weight and shoot dry weight were decreased according to increasing the planting density. From the above results, we concluded that optimum nutrient solution, optimum levels of pH, irrigation interval, light intensity and planting density were 6.0-7.0 and 10 min, $180{\mu}mol{\cdot}m^{-2}{\cdot}s^{-1}$ and $15{\times}15cm$, respectively for growth of common ice plant in a closed-type plant production system.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.60 no.4
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• pp.491-497
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• 2015

Small-sized tuber of sweet potato (Ipomoea batatas Lam.) is more preferred by Korean consumers, because it is convenient to eat with hands, and can easily be steamed or roasted in small pan as a healthy snack for a small family. The present study was aimed to investigate the effect of high-density plantings and harvesting times on production of smallsized tuber (50~200 g). Four varieties ('Annobeny', 'Daeyumi', 'Shinzami', and 'Yeonhwangmi') were planted in 2-row zigzag high-density planting ($75{\times}30cm$, A; $75{\times}25cm$, B) and 1-row planting ($75{\times}25cm$, control) covered with black vinyl film on May 23th, 2014. Marketable yields and small-sized tuber yields were compared between 120- and 150-day harvesting. Vine length and fresh weight per plant were significantly decreased in 2-row planting A and B plots compared to the control at 120 days after planting. Weight of tuber per plant, mean weight of tuber and number of tuber per plant were significantly decreased in 120-day harvesting of A and B plots than in the control. Marketable yields per 10a were increased by 17% ($2.4ton{\cdot}10a^{-1}$) and 8% ($2.6ton{\cdot}10a^{-1}$) in 120-day harvesting of A and B plots compared to the control ($2.4ton{\cdot}10a^{-1}$), and those were largely increased by 29% ($4.0ton{\cdot}10a^{-1}$) and 26% ($3.9ton{\cdot}10a^{-1}$) in 150-day harvesting than in the control ($3.1ton{\cdot}10a^{-1}$). Proportions of small size tuber (50~200 g) were increased by about 65% in 150-day harvesting of A and B plots compared to the control (55.3%). Small-size tuber yield and marketable yield were highly increased in 150-day harvesting of 2-row zigzag high-density planting A ($75{\times}30cm$).

• Food Science and Preservation
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• v.24 no.2
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• pp.215-220
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• 2017

Cut Kimchi cabbages ($3{\times}3cm$) were dipped in the egg shell solution (0.5% egg shell calcium/0.5% citric acid solution) and stored in the low-density polyethylene (LDPE) film bag at $4^{\circ}C$ for 2 weeks. Using this cut Kimchi cabbage, kimchi was prepared and their physicochemical qualities were investigated. Moreover, their sensory qualities were compared with Kimchi prepared with normal Kimchi cabbages. Egg shell calcium pretreatment (ET) showed the lower weight loss of cabbages than non-treatment (NT), and soluble solid compounds were decreased in all samples. Titratable acidity showed no statistical difference. After making a kimchi using cut Kimchi cabbages stored for 2 weeks no statistical differences in soluble solids and titratable acidities of kimchi stored for 7 days were shown. As a result of sensory test, preference of color was decreased and salted condition of control was the most significantly decreased. Pickled seafood odor of kimchi showed statistical difference, compared with the control. Crispness decreased in all samples. On the other hand, salty flavor and pickled seafood flavor were increased, fresh cabbage flavor, bitter flavor and carbonic flavor were decreased. Overall sensory quality of cut Kimchi cabbage (ETK) didn't show significant difference compare with kimchi prepared with normal cabbage (CON). It is possible to make kimchi with approvable sensory quality using cut Kimchi cabbage treated with egg shell calcium.

• Korean Journal of Food Science and Technology
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• v.27 no.4
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• pp.537-545
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• 1995

Quality changes of lettuce were studied during storage to investigate the efficiency, cooling properties and the washing and storage effects of immersion-type hydrocooling. As a result of plotting the nondimensionalized lettuce temperature versus cooling time, its cooling rate coefficient was shown to be $-0.365\;min^{-1}{\sim}-0.255\;min^{-1}\;(R^2=0.99{\sim}0.88)$. Rate of weight loss was not significantly (p>0.05) different between lettuces with various treatment conditions during storage at $5^{\circ}C$. However, during storage at $15^{\circ}C$, weight loss of hydrocooled lettuce was lower than that of non-treated lettuce after from 10 to 15 days. Especially, The lettuce packed with PE was more effective than that packed with try in terms of packing condition after hydrocooling. Lettuce pretreated with sterilizing agent, packed with PE vinyl film, removed residual water after hydrocooling had lower decaying rate than any other lettuces. Changes of L and b values in hydrocooled lettuce were slower than those of non-treated one. During changes of chlorophyll content, the initial value, $115.7{\sim}147.3\;mg%$ was decreased to $50{\sim}60%$ after 25 days of storage at $5^{\circ}C$ and within 15 days of storage at $15^{\circ}C$. It could be presumed that the addition of sterilizing agent reduced the initial level of overall total and coliform count and its growth rate during storage. The respiration rate of hydrocooled lettuce at $5^{\circ}C$ was $23.95\;mg{\cdot}CO_2/kg\;hr$, which is 10% of those of non-treated lettuce.

• Advances in pediatric surgery
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• v.16 no.1
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• pp.1-10
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• 2010

The members of the Korean Association of Pediatric Surgeons conducted a retrospective study of two hundred and twenty-two cases of intestinal atresia for the period from January 1, 2007 to December 31, 2009. Seventeen hospitals were involved. There were 76 duodenal, 65 jejunal, and 81 ileal atresias (3 colonic). The male to female ratio was 0.85:1 in DA and 1.34:1 in JIA. Ninety-four patients(43.3 %) were premature babies (DA 40.3 %, JA 64.6 %, IA 28.8 %), and 70 babies (32.0 %) had low birth weight (DA 38.7 %, JA 44.4 %, IA 16.0 %). Antenatal diagnosis was made in 153 cases (68.9 %). However, 27 infants (17.6 %) with antenatal diagnosis were transferred to the pediatric surgeon's hospitals after delivery. Maternal polyhydramnios was observed in 81 cases (36.59 %) and most frequent with proximal obstruction. In forty-four cases (19.8 %), only simple abdominal film was taken for diagnostic study. The associated malformations were more frequently observed in DA - 61.8 % in DA and 22.6 % in JIA. Meconium peritonitis, small bowel volvulus and intussusception were more frequently associated with ileal atresia. The overall mortality rate was 3.6 %. (Abbreviations: DA;duodenal atersia, JA;jejunal atresia, JIA;jejunoileal atresia, IA;ileal atrsia).

• Journal of Life Science
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• v.24 no.6
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• pp.595-602
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• 2014

Styela Clava tunic (SCT) has found some applications in many areas of medical treatment including as an anti-inflammatory compound, a wound healing film, in guided bone regeneration, and as a food additive. The protective effect of SCT aqueous extract (AE-SCT) on cell death induced by $H_2O_2$ treatment was investigated by measuring the changes in cell viability in HepG2 cells after AE-SCT treatment. High concentrations of antioxidant compounds including flavonoids (3.3 mg/g) and phenolics (32.3 mg/g) were detected in AE-SCT but no significant cytotoxicity was observed in HepG2 cells treated with AE-SCT. The viability of HepG2 cells was also not changed by treatment with different concentrations of AE-SCT after $H_2O_2$ treatment. However, cell viability was significantly increased in cells treated with three different concentrations of AE-SCT before $H_2O_2$ treatment. The greatest increase in cell viability was observed in the group treated with $50{\mu}g/ml$ AE-SCT, when compared with vehicle-treated group. FACS and DAPI staining analysis indicated that the decrease in number of dead cells was dependent on the concentration of AE-SCT. Alterations in the Bax/Bcl-2 ratio after $H_2O_2$ treatment were significantly restored by treatment with different concentrations of AE-SCT. These results indicate that AE-SCT, which contains high levels of antioxidants, may protect cells against death induced by $H_2O_2$ treatment.