• Journal of Dental Rehabilitation and Applied Science
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• v.34 no.4
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• pp.297-305
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• 2018

Purpose: This study aimed to analyze stress distribution and maximum von Mises stress generated in intracoronal restorations and in tooth structures of mandibular molars with various types of cavity designs and materials. Materials and Methods: Three-dimensional solid models of mandible molar such as O inlay cavity with composite and gold (OR-C, OG-C), MO inlay cavity with composite and gold (MR-C, MG-C), and minimal invasive cavity on occlusal and proximal surfaces (OR-M, MR-M) were designed. To simulate masticatory force, static axial load with total force of 200 N was applied on the tooth at 10 occlusal contact points. A finite element analysis was performed to predict stress distribution generated by occlusal loading. Results: Restorations with minimal cavity design generated significantly lower values of von Mises stress (OR-M model: 26.8 MPa; MR-M model: 72.7 MPa) compared to those with conventional cavity design (341.9 MPa to 397.2 MPa). In tooth structure, magnitudes of maximum von Mises stresses were similar among models with conventional design (372.8 - 412.9 MPa) and models with minimal cavity design (361.1 - 384.4 MPa). Conclusion: Minimal invasive models generated smaller maximum von Mises stresses within restorations. Within the enamel, similar maximum von Mises stresses were observed for models with minimal cavity design and those with conventional design.

• Korean Journal of Remote Sensing
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• v.39 no.6_2
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• pp.1565-1576
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• 2023

An atmospheric correction algorithm based on the radiative transfer model is required to obtain remote-sensing reflectance (R_rs) from the Geostationary Ocean Color Imager-II (GOCI-II) observed at the top-of-atmosphere. This R_rs derived from the atmospheric correction is utilized to estimate various marine environmental parameters such as chlorophyll-a concentration, total suspended materials concentration, and absorption of dissolved organic matter. Therefore, an atmospheric correction is a fundamental algorithm as it significantly impacts the reliability of all other color products. However, in clear waters, for example, atmospheric path radiance exceeds more than ten times higher than the water-leaving radiance in the blue wavelengths. This implies atmospheric correction is a highly error-sensitive process with a 1% error in estimating atmospheric radiance in the atmospheric correction process can cause more than 10% errors. Therefore, the quality assessment of R_rs after the atmospheric correction is essential for ensuring reliable ocean environment analysis using ocean color satellite data. In this study, a Quality Assurance (QA) algorithm based on in-situ R_rs data, which has been archived into a database using Sea-viewing Wide Field-of-view Sensor (SeaWiFS) Bio-optical Archive and Storage System (SeaBASS), was applied and modified to consider the different spectral characteristics of GOCI-II. This method is officially employed in the National Oceanic and Atmospheric Administration (NOAA)'s ocean color satellite data processing system. It provides quality analysis scores for R_rs ranging from 0 to 1 and classifies the water types into 23 categories. When the QA algorithm is applied to the initial phase of GOCI-II data with less calibration, it shows the highest frequency at a relatively low score of 0.625. However, when the algorithm is applied to the improved GOCI-II atmospheric correction results with updated calibrations, it shows the highest frequency at a higher score of 0.875 compared to the previous results. The water types analysis using the QA algorithm indicated that parts of the East Sea, South Sea, and the Northwest Pacific Ocean are primarily characterized as relatively clear case-I waters, while the coastal areas of the Yellow Sea and the East China Sea are mainly classified as highly turbid case-II waters. We expect that the QA algorithm will support GOCI-II users in terms of not only statistically identifying R_rs resulted with significant errors but also more reliable calibration with quality assured data. The algorithm will be included in the level-2 flag data provided with GOCI-II atmospheric correction.

• KOREAN JOURNAL OF CROP SCIENCE
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• v.59 no.4
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• pp.470-476
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• 2014

The purpose of this study was to investigate the effects of sowing time on ecological responses, growth, and yields of cowpeas grown in plastic greenhouses in a southern region of South Korea. Experiments were carried out in Naju, Jeonnam Province (Latitude $35^{\circ}$ 04' N, Longitude $126^{\circ}$ 54' E) during 2012 and 2013. The intermediate-erect type strains used in this study were Jeonnam1 and Jeonnam2. Sowing was performed between mid-March and mid-August at intervals of one month. The days from sowing to emergence was significantly higher for the mid-March sowing (12 days) but no significant differences were observed among the other sowing dates (3 to 4 days). The days from sowing to first flowering were shorter for sowing dates between mid-March and mid-July because sowing time was delayed and then were lengthened again at mid-August sowing; the days were longest at mid-March sowing (around 75 days) and were shortest at mid-July sowing (30 days). The days from first flowering to harvesting were short for the sowing dates between mid-March and mid-May (24 to 28 days) but were relatively long for subsequent sowing dates (35 to 38 days). Stem and peduncle lengths were relatively long for the mid-April and mid-August sowing dates. Main-stem node number was highest for the mid-June sowing. Branch number per plant was highest for the mid-March sowing. The mid-March sowing displayed the highest number of pods per plant as well as the heaviest seed weight. Yield per 10 ares was highest for the mid-March sown Jeonnam1 and the Jeonnam2 strains (340 and 367 kg respectively), and then tended to decrease due to subsequent delays in sowing.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.311-319
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• 2014

Early sexual maturation through temperature stimulation was induced in female and male of yezo scallop. Gonadosomatic index (GSI) in female showed $9.12{\pm}2.9$ in January, $14.89{\pm}2.9$ in February and $21.3{\pm}1.4$ in March in experiment I. GSI in experiment I showed a significant increase (P < 0.05) and in experiments II and III were not show significant variations (P > 0.05). It also showed significant between the control and the experiments I, II, and III in February (P < 0.05) measurements. Experiment I has showed good results in sexual maturation and spawning when compared with other experiments II and III and the control. Histological observation showed that ovary condition was in a growing stage in all the experiments I, II, and III. In February, ovary condition through histological observation was a late mature stage in all the experiments I, II, and III except the control of a growing stage. GSI and gonad weight were $4.4{\pm}0.88$ and 2.8 g, respectively in November whereas it was $15.1{\pm}2.8$, and 11.7 g, respectively in January and $21.7{\pm}5.4$, and 19.4 g, respectively in February after rearing at a water bath of $12^{\circ}C$ depending on the condition of experiment I. It was possible early releasing of eggs and sperms of yezo scallop in February instead of the middle of April to the end of May being spawning period. Fertilized eggs have become a gastrula stage through a spiral cleavage and then become a trochophore larvae after 36 hours. After 10 days, D-shaped larvae have changed into an umbo stage larvae and attached to juveniles in the post larvae after 20-23 days.

• The Korean Journal of Malacology
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• v.30 no.4
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• pp.321-331
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• 2014

Patinopecten yessoensis is known to be farmed only in the northern part of the East Sea today. In an attempt to extend its production area, we have conducted experiments both in the northern and southern parts of the East Sea and studied on their growth in an aim to use the results for increasing overall productivity of the species. Early juvenile scallops producted in February 2014 showed an average shell length of $0.23{\pm}0.002$. The high growth group showed an average shell length and shell height of $4.11{\pm}0.08mm$ and $4.28{\pm}0.09mm$, respectively, in June while they were $23.63{\pm}3.4mm$ and $24.19{\pm}4.5mm$ in October. The low growth group showed an average shell length and shell height of $2.23{\pm}0.7mm$ and $1.99{\pm}0.9mm$, respectively, in June while they were $1.99{\pm}0.9mm$ and $17.59{\pm}4.5mm$ in October. The daily growth rate of the high growth group was 0.037 mm/day and 0.027 mm/day for the low growth group. In August, we measured the shell length of Patinopecten yessoensis from Yangyang-gun, Gangneung-si, Yeongdeok-gun, and Pohang-si. Patinopecten yessoensis from Pohang-si showed the best growth performance with its shell length of $26.90{\pm}3.6mm$. Patinopecten yessoensis from Yeongdeok was the second largest with its shell length of $23.56{\pm}3.4mm$. We presume that optimal water temperature and phytoplankton abundance of the two regions have contributed to the good growth performance of the species.

• Journal of the Society of Cosmetic Scientists of Korea
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• v.42 no.4
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• pp.359-366
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• 2016

Exosome, a small vesicle secreted from cells, has diverse functions depending on cell origins and tissue types and plays a important role in cell viability and intercellular communication. Recently, many researchers have demonstrated the use of exosomes for the treatment of cancers and immune diseases, and the development of diagnostic biomarker. However, the secretion mechanism of exosome from skin cell and its physiological functions in skin remain unclear. Thus, this study aimed to explore whether keratinocyte-derived exosome affects proliferation and migration in HaCaTs. Exosomes were isolated from HaCaTs by ExoQuick-TC and then boiled or unbolied. Boiled and unboiled exosome induced proliferation in HaCaTs in a dose-dependant manner ($0.1{\sim}20{\mu}g/mL$), respectively. Boiled and unboiled exosome at concentration of $20{\mu}g/mL$ increased proliferation level in HaCaTs by $186.96{\pm}3.87%$ and $193.48{\pm}10.48%$ compared with control group. Unboiled exosome stimulated migration in HaCaTs in a dose-dependent manner ($0.1{\sim}20{\mu}g/mL$), which reached a maxium at concentration of $20{\mu}g/mL$ ($179.39{\pm}4.89%$ of control), but boiled exosome did not affect HaCaT migration. In addition, unboiled exosome ($0.1{\sim}20{\mu}g/mL$) dose-dependently stimulated sprout outgrowth in HaCats. These results demonstrate that in exosome from HaCaTs, heat-stable components such as lipid may induce HaCaT proliferation and heat-unstable components such as protein may stimulate migration and sprout outgrowth in HaCaTs, thereby leading to reepithelialization and skin-wound healing activities. It is concluded that exosomes from HaCaTs may be used as cosmetic materials.

• Journal of radiological science and technology
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• v.37 no.4
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• pp.239-246
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• 2014

Filter absorbs low-energy X-ray to increase the average energy and reduces patient exposure dose. This study investigates if the materials of Mo and W could be used for the digital imaging device CR by conducting image assessment and dose measurement of SNR, FOM and histogram. In addition, measurement of beam quality was conducted depending on the material of the filter, and at the same time, a proper combination of filters was examined depending on the change in tube voltage (kVp). In regard to entrance skin dose, Mo filter showed the dose reduction by 42~56%, compared to Cu filter. Moreover, Mo filter showed higher transmission dose by around 1.5 times than that of Cu filter. In image assessment, it was found that W was unsuitable to be used as a filter, whereas Mo could be used as a filter to reduce dose without decline in image quality at the tube voltage of 80 kVp or higher. As tube voltage increased, 2.0 mm Al+0.1 mm Mo almost had a similar histogram width to that of 2.0 mm Al+0.2 mm Cu. Therefore, Mo filter can be used at relatively high tube voltage of 80 kVp, 100 kVp and 120 kVp. The SNR of 2.0 mm Al+0.1 mm Mo did not show any significant difference from those of 2.0 mm Al+0.2 mm Cu and 2.0 mm Al+0.1 mm Cu. As a result, if Mo filter is used to replace Cu filter in general radiography, where 80 kVp or higher is used for digital radiation image, patient exposure dose can be reduced significantly without decline in image quality, compared to Cu filter. Therefore, it is believed that Mo filter can be applied to chest X-ray and high tube voltage X-ray in actual clinical practice.

• Journal of radiological science and technology
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• v.38 no.3
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• pp.305-313
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• 2015

After Fukushima Daiichi nuclear disaster in 2011, study and maintenance of monitoring systems have been made at home and abroad. As concerns about radioactive contamination of water have increased in Korea, update of maintenance of managing radioactive materials in water is being made mainly by Ministry of Environment. In this study, we analysed current state of monitoring system modification in Japan, the country directly involved and neighboring country. According to the result, Japan modified the legislations first. Then Ministry of Education, Culture, Sports, Science and Technology (MEXT) provides theoretical background of radiological monitoring. And Ministry of the Environment actually watches state of water pollution in public waters and underground water. Finally related agencies like local government are monitoring current state of radioactive contamination in water environment. By region, local monitoring stations share the investigation of the whole country. Also, additional monitoring is running around nuclear facilities. After Fukushima disaster, monitoring for area near Fukushima is added. Among the reference levels, management target value of drinking water and tap water is 10 Bq/kg, and those of public water and underground water are 1 Bq/L. Measuring intervals varied from every hour to once a year, regularly or irregularly depending on the investigation. The main measuring items are air dose rate, gross ${\alpha}$, gross ${\beta}$, ${\gamma}$ radionuclide, Cs-134, Cs-137, Sr-89, Sr-90, I-131, and so on. In comparison, regulations about general public water in Korea need to be modified, while those about area near nuclear facility and drinking water are organized well. In future, therefore, domestic system would be expected to be modified with making reference to the guidelines like WHO's one. As good case of applying international guideline to domestic environment, Japanese system could be a reference when general standard of radioactivity in public water is made in Korea.

• Journal of the Korean Society of Food Science and Nutrition
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• v.39 no.5
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• pp.655-661
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• 2010

The nutraceutical role of fermented omija (Schizandra chinensis) beverage (FOB) was determined through the analysis of fibrinolytic and alcohol metabolizing activities, nitrite scavenging activity, and angiotensin converting enzyme and $\alpha$-glucosidase inhibitory effects. Firstly, FOB increased fibrinolytic activity in a dose-dependent manner and indicated angiotensin converting enzyme inhibitory activity of 94.8% at 20% FOB (0.6 mg/mL). In addition, the inhibitory activities of FOB on $\alpha$-amylase and $\alpha$-glucosidase were determined to be 100% at 100% FOB (3 mg/mL) and 49% at 60% FOB (1.8 mg/mL), respectively. Nitrite scavenging activity of FOB was about 96.1%, 72.3%, and 68.3% on pH 1.2, 3.0, and 6.0 at 100% FOB, respectively. To determine influence of FOB on alcohol metabolism, the generating activities of reduced-nicotinamide adenine dinucleotide (NADH) by alcohol dehydrogenase (ADH) and acetaldehyde dehydrogenase (ALDH) were measured. Facilitating rate of ADH activity was 70.3% at 50% FOB, but ALDH activity was not affected. These results revealed that FOB has a strong alcohol metabolizing activity, and fibrinolytic and nitrite scavenging activities and exhibits the angiotensin converting enzyme, $\alpha$-amylase, and $\alpha$-glucosidase inhibitory activities.

• Journal of Life Science
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• v.18 no.8
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• pp.1106-1114
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• 2008

The antioxidants activities in water and 95% ethanol extracts of wa-song (Orostachys japonicus A. Berger) dried by sun, hot air and lyophilization were measured in vitro reaction system. In reaction system containing linoleic acid, the antioxidant activities against lipid oxidation enhanced in proportion to storage time. The antioxidant activity of ethanol extracts was higher than that of water extracts. In the drying methods, wa-song extracts showed higher antioxidant activity in the other of hot air-dried, lyophilized and sun-dried. The lipid oxidation system containing the promoting factors, such as $Fe^{+2}$ and $Cu^{+2}$ions, also showed that the ethanol extract of hot air-dried wa-song possessed the highest antioxidant activity. Soybean oil and lard being added with various levels (0.1, 0.5 and 1.0 g/100 g) of the ethanol extract of hot air-dried wa-song were stored at $60^{\circ}C$ (for 28 days) or $180^{\circ}C$ (for 48 hr). Its extract appeared to lower the acid value of soybean oil, wheras it failed to lower the acid value for lard at early storage time, but it was lower than control and BHT after 28 days. Anicidine value and peroxide value were lower soybean and lard added wa-song extract than control and BHT for storage for 28 days at $60^{\circ}C$. In 28 days, its value was significantly decreased in proportion to sample concentration. TBA value was increased during storage time at $60^{\circ}C$, but it was significantly decreased by sample concentration after storage 36 hours at $180^{\circ}C$ storage. Therefore results suggest ethanol extract of hot air-dried wa-song could be potential candidates for natural antioxidants for materials containing lipid.