• Proceedings of the KSRS Conference
• /
• 2007.10a
• /
• pp.243-245
• /
• 2007

This study was begun to classify the paddy fields by the rice varieties and to monitor the temporal change in rice growth using SAR backscatter coefficients $({\sigma}^{circ})$. For nine fine-beam mode images of Radarsat-1 SAR, a growing period time-series of backscatter coefficients was set up from April to October in 2005, and was compared with the field-measured rice growth parameters such as LAI (leaf area index), plant height, fresh and dry biomass, and water content in grain and plant for 45 parcels in Dangjin-gun, Chungcheongnam Province, South Korea. The average backscatter coefficients for early-maturing rice varieties (13 parcels) were ranged from -18.17dB to -6.06dB and were lower than for medium-late maturing rice varieties during most of the growing season. At around the heading stage (July 30) for early-maturing rice, both rice crops showed the highest backscatter coefficient values and the difference was the greatest before harvesting early-maturing rice. The temporal difference in backscatter coefficients between rice varieties was expected to play a key role to identify early-maturing rice fields. On the other hand, comparison with field-measured rice growth parameters showed that the backscatter coefficients decreased or stayed on the plateau after heading stage even though the growth of rice canopy advanced.

• Korean Journal of Applied Biomechanics
• /
• v.19 no.3
• /
• pp.603-610
• /
• 2009

The purpose of this study was to determine how spandex pants affect impact force and muscle activities in the lower extremity. Seven pairs of surface electrodes were attached to the right-hand side of the body. Paired t-test was performed to test if significant difference exist between two conditions(p< .05). The average IEMG activities in the TA, BF, and GM during the landing phase reduced significantly with spandex pants compared to regular pants. All peak IEMG activities except the RF in wearing spandex pants group were significantly greater than the corresponding values in wearing regular pants one. The greater muscle activity recorded in wearing spandex pants can be attributed to the greater motor unit recruitment needed to decelerate and stabilized their bodies. Impact force and loading rate were not significantly decreased with wearing spandex pants. Since the spandex pants used in this study were not custom-fit based on girth of each participants thigh and shank, compression and elasticity for the pants could not be optimized.

• Toxicological Research
• /
• v.31 no.1
• /
• pp.41-48
• /
• 2015

Owing to the increase in price of cigarettes in Korea, herbal cigarettes have received increasing attention as a non-smoking aid; however, its safety has hardly been studied. We analyzed some of the toxic components in the mainstream smoke of herbal cigarettes, performed a mutagenicity test on smoke condensates for safety assessment, and compared the results with the corresponding values of a general cigarette with the same tar content. Herbal cigarette "A" was smoked using automatic smoking machine under ISO conditions in a manner similar to general cigarette "T". The tar content measured was higher than that inscribed on the outside of a package. The mainstream smoke of herbal cigarette "A" did not contain detectable levels of tobacco-specific nitrosamines and nicotine. Carbon monoxide and benzo(${\alpha}$)pyrene contents in herbal cigarette "A" were higher than those in the general cigarette "T". The phenolic contents such as hydroquinone, resorcinol, and catechol in herbal cigarette "A" were higher than those in the general cigarette "T", but cresol contents in herbal cigarette "A" were lower than those in the general cigarette "T". The content of aromatic amines such as 4-aminobiphenyl in herbal cigarette "A" was higher than that in the general cigarette "T"; however, this difference was not statistically significant. On the other hand, 1-aminonaphthalene, 2-aminonaphthalene, and 3-aminobiphenyl contents in herbal cigarette "A" were lower than those in the general cigarette "T". The smoke condensates of herbal cigarette "A" exhibited a higher mutagenic potential than the condensates from the general cigarette "T" at the same concentration. We concluded that the mainstream smoke of herbal cigarette contains some toxic components, the smoke condensates of herbal cigarettes are mutagenic similar to general cigarette because of combustion products, and that the evaluation of the chemical and biological safety of all types of herbal cigarettes available on the market.

• Korean Journal of Pharmacognosy
• /
• v.49 no.3
• /
• pp.270-277
• /
• 2018

Pyungwi-san has been used to treat the digestive system diseases, physconia, nausea, anorexia, and dyspepsia in Korea. In this study, an ultra-performance liquid chromatography-electrospray ionization-mass spectrometry (UPLC-ESI-MS/MS) method was optimized for simultaneous determination of the 14 marker components, spinosin, liquiritirn apioside, liquiritin, narirutin, 6'''-feruloylspinosin, hesperidin, liquiritigenin, glycyrrhizin, 6-gingerol, atractylenolide III, honokiol, atractylenolide II, magnolol, and atractylenolide I in Pyungwi-san extract. All analytes were separated on a Waters Acquity UPLC BEH $C_{18}$ analytical column ($2.1{\times}100mm$, $1.7{\mu}m$) with maintained at $45^{\circ}C$. The mobile phase consisted of 0.1% (v/v) aqueous formic acid and acetonitrile. The MS conditions were as follows: capillary voltage 3.3 kV, extractor voltage 3.0 V, RF lens voltage 0.3 V, source temperature $120^{\circ}C$, desolvation temperature $300^{\circ}C$, desolvation gas 600 L/h, cone gas 50 L/h and collision gas 0.14 mL/min. The coefficient of determination of 14 analytes was 0.9989-1.0000. The limits of detection and quantification values of the all analytes were 0.04-2.56 and 0.13-7.69 ng/mL, respectively. As a result of the analysis using the established LC-ESI-MS/MS method, the 5 components, spinosin, 6'''-feruloylspinosin, atractylenolide III, II, and I derived from Zizyphi Fructus and Atractylodis Rhizoma, were not detected in this extract. On the other hand, the 9 components except for the 5 components were 4.15-498.87 mg/kg in lyophilized Pyungwi-san extract. Among these components, glycyrrhizin, marker compound of Glycyrrhizae Radix et Rhizoma, was detected the most amount as a 498.87 mg/kg.

• Journal of Korean Society on Water Environment
• /
• v.33 no.3
• /
• pp.326-333
• /
• 2017

The lakes and reservoirs have been reported as important sources of carbon emissions to the atmosphere in many countries. Although field experiments and theoretical investigations based on the fundamental gas exchange theory have proposed the quantitative amounts of Net Atmospheric Flux (NAF) in various climate regions, there are still large uncertainties at the global scale estimation. Mechanistic models can be used for understanding and estimating the temporal and spatial variations of the NAFs considering complicated hydrodynamic and biogeochemical processes in a reservoir, but these models require extensive and expensive datasets and model parameters. On the other hand, data driven machine learning (ML) algorithms are likely to be alternative tools to estimate the NAFs in responding to independent environmental variables. The objective of this study was to develop random forest (RF) and multi-layer artificial neural network (ANN) models for the estimation of the daily $CO_2$ NAFs in Daecheong Reservoir located in Geum River of Korea, and compare the models performance against the multiple linear regression (MLR) model that proposed in the previous study (Chung et al., 2016). As a result, the RF and ANN models showed much enhanced performance in the estimation of the high NAF values, while MLR model significantly under estimated them. Across validation with 10-fold random samplings was applied to evaluate the performance of three models, and indicated that the ANN model is best, and followed by RF and MLR models.

• Journal of the Korean Society of Industry Convergence
• /
• v.23 no.1
• /
• pp.83-91
• /
• 2020

The evaluation of the compression behavior of the cushioning material is of importance to achieve appropriate packaging design. In order to change packaging design from polymeric-based to more eco-friendly cellulose-based nire effectively, comparative study on the compression behavior between these two packaging materials is crucial. In this study, the stress-strain behavior, hysteresis loss, and response characteristics for cyclic loading were analyzed through compression tests on multi-layered corrugated structure (MLCS) and expanded polystyrene (EPS) packaging materials. MLCS produced in Korea is produced by winding a certain number of single-faced corrugated paperboard, and the compression behavior of this material was turned out to be 6 stages: elastic stage, first buckling stage, sub-buckling stage, densification stage, last buckling stage and high densification stage. On the other hand, EPS's compression behavior was in 3 stages: linear elastic stage, collapse plateau, and densification stage. The strain energy per unit volume (strain energy density) of MLCS did not differ depending on the material thickness, but it showed a clear difference depending on the raw material and flute type. Hysteresis loss of MLCS ranged from 0.90 to 0.93, and there were no significant differences in the raw material and flute type. These values were about 5 to 20% greater than the hysteresis of the EPS (about 0.78 to 0.87).

• Korean Journal of Clinical Laboratory Science
• /
• v.43 no.3
• /
• pp.113-119
• /
• 2011

This study was designed to determine the effects of larval extracts from Protaetia brevitarsis seulensis shade dried larva from Korea and China on liver tissues of hepatic injury groups. The experimental groups are divided into five groups; Normal, carbon tetrachloride single injection ($CCl_4$), Pb-CHI ($CCl_4$ + P. brevitarsis shade dried larva from China), Pb-KOR ($CCl_4$ + P. brevitarsis shade dried larva from Korea) and SIL ($CCl_4$ + 0.35% silymarin) groups. Sprague Dawley rats were oral injected with $CCl_4$ at a dose l mg/kg (20% in corn oil) for induction of liver damage for 4 weeks. Each experimental group was fed with a dose 50 mg/kg of larval extracts based on medicinal preparations from 3 weeks to 4 weeks after $CCl_4$ treatment. At the end of 4 weeks, we evaluated the serum levels of glutamate-oxaloacetate transaminase (GOT), glutamate-pyruvate transferase (GPT), alkaline phosphatase (ALP) and blood urea nitrogen (BUN) in serum and the cytokine levels of tumor necrosis factor-${\alpha}$) (TNF-${\alpha}$) and transforming growth factor-${\beta}$ (TGF-${\beta}$) in the cells isolated from spleen and liver. The histological analysis was also conducted. The $CCl_4$ injection reduced body weight, induced congestion of middle lobe and hepatocytic degeneration, resulting in disintegration of hepatic cords, and increased biochemical markers of blood related to hepatic injury. On the other hand, the Pb-CHI and Pb-KOR group decreased the levels of biochemical markers in blood and cytokine levels in spleen and liver. Especially, the Pb-KOR group facilitated the recovery of biochemical values of blood related to hepatic injury, hepatic lesions and fibrosis. Taken together, larval extract from P. brevitarsis might prevent acute hepatotoxicity and enhance the recovery of liver fibrosis and cirrhosis induced by $CCl_4$, and the ingredients could be a promising candidate for the prevention and treatment of hepatic disorders.

• Journal of the Korean Society of Surveying, Geodesy, Photogrammetry and Cartography
• /
• v.24 no.4
• /
• pp.313-318
• /
• 2006

Recently, the single plane coordinate system which has one origin is required to create and manage continuous geographic framework data of entire Korean peninsula. For this, UTM-K (Univercial Transverse Mercator-K) was established in 2005. In this paper, the level of distortion was analyzed with respect to the central meridian and scale factor of UTM-K. The latitude and longitude values of the center point of 1/25000 scale digital maps were used for calculating the scale factor which was created by projection and the scale factor was used for index that presents the degree of distortion. As a result, accumulated distortion of scale factor by UTM-K map projection showed about $23.744{\times}10^{-2}$. On the other hand, the minimum distortion which was about $5.1435{\times}10^{-2}$ occurred when central meridian is $127^{\circ}\;42'$ and scale factor of central meridian was 0.99994 respectively.

• The Korean Journal of Food And Nutrition
• /
• v.26 no.3
• /
• pp.428-437
• /
• 2013

The physical properties of jellified soybean curd residue (Biji) with the addition of various gums were investigated to optimize the direct availability of a by-product of the tofu production process. The lightness (L value) of the jellified Biji prepared with various gums was approximately 77~80, regardless of the concentration of gum used. Especially at the concentration of 0.1% and 0.3%, a pectin showed a significantly higher value compared with other gelling agents (carrageenan and agar). The strength of samples prepared on the basis of carrageenan showed the value of 335~569 $g/cm^2$ and 234~335 $g/cm^2$ according to the addition of locust bean gum and xanthan gum, respectively. On the other hand, the samples made with pectin and agar were 134~272 $g/cm^2$ and 50~215 $g/cm^2$, respectively. Where locust bean gum was used as a viscous agent, the adhesiveness of sample prepared by adding carrageenan was greater than those made with pectin or agar. The values were -6.0~-11.0 g, -2.7~-10.2 g and -3.7~-7.0 g, respectively. Overall, the strength and adhesiveness of samples according to increase of the added amount of Biji showed constantly increasing trend regardless of the type of gelling agent used. In the sample containing carrageenan this trend was most noticeable.

• Korean Journal of Pharmacognosy
• /
• v.40 no.1
• /
• pp.1-5
• /
• 2009

The antioxidant and anti-diabetes effects were evaluated by the ethanol extracts from Astragalus membranaceus root classified by years using through DPPH radical scavenging activity, hydroxyl radical (${\cdot}OH$) scavenging activity, total phenolic and flavonoid contents, reducing power activity, $\alpha$-amylase and $\alpha$-glucosidase inhibitory activities. $IC_{50}$ values for DPPH radical scavenging activity of ethanol extract from 6 years old root ($749.25{\mu}g/mL$) was higher than 1 year ($1452.67{\mu}g/mL$) and 3 years old root ($1095.61{\mu}g/mL$). 6 years old root showed better effects in ${\cdot}OH$ scavenging activity ($IC_{50}$: $10.58{\mu}g/mL$), reducing power, total phenolic contents ($26.13{\pm}0.79\;Tan\;{\mu}g/mg$, $24.03{\pm}0.74\;Cat\;{\mu}g/mg$) $\alpha$-amylase ($33.33{\pm}0.55%$) and $\alpha$-glucosidase inhibitory activity ($49.71{\pm}1.01%$). On the other hand, total flavonoid compound contents were estimated much higher in 1 year old root ($44.93{\pm}1.35\;Que\;{\mu}g/mg$, $70.32{\pm}2.03\;Rut\;{\mu}g/mg$) than others. Based on these results, It was suggested that 6 years old root of A. membranaceus has a potential candidate for functional cosmetic and medicine.