• Journal of Mushroom
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• v.14 no.4
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• pp.244-248
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• 2016

In order to isolate thermophilic bacteria with high activity of CMCase and xylanase, spent mushroom substrates was collected from an oyster mushroom cultivation farm in Jinju, Gyeongnam, Korea. Among the isolates, one strain designated as YJ09 was selected by agar diffusion method. The isolate YJ09 was identified as a member of Bacillus licheniformis based on biochemical characteristics using Bacillus ID kit and MicroLog system. Comparative 16S rDNA sequence analysis showed that isolate YJ09 formed a distinct phylogenetic tree within the genus Bacillus and was most closely related to Bacillus licheniformis with sequence similarity of 98.9%. Based on its physiological properties, biochemical characteristics and phylogenetic distinctiveness, the isolate YJ09 was classified as Bacillus licheniformis. The CMCase and xylanase activity of B. licheniformis YJ09 was slightly increased corresponding to the bacterial population from exponential phase to stationary phase in the growth curve of B. licheniformis YJ09.

• Journal of the Korean Society of Safety
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• v.34 no.4
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• pp.1-5
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• 2019

In the field of combined cycle power generation, thermal barrier coating(TBC) protects the super-heat-resistant alloy, which forms the core component of the gas turbine, from high temperature exposure. As the turbine inlet temperature(TIT) increases, TBC is more important and durability performance is also important when considering maintenance cost and safety. Therefore, studies have been made on the fabrication method of TBC and super-heat-resistant alloy in order to improve the performance of the TBC. In recent years, due to excellent properties such as high temperature creep resistance and high temperature strength, turbine blade material have been replaced by a single crystal superalloy, however there is a lack of research on TBC applied to single crystal superalloy. In this study, to understand the isothermal degradation performance of the TBC applied to the single crystal superalloy, isothermal exposure test was conducted at various temperature to derive the delamination life. The growth curve of thermally grown oxide(TGO) layer was predicted to evaluate the isothermal degradation performance. Also, microstructural analysis was performed by scanning electron microscope(SEM) and energy dispersive X-ray spectroscopy (EDS) to determine the effect of mixed oxide formation on the delamination life.

• Journal of the Korea institute for structural maintenance and inspection
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• v.19 no.5
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• pp.45-55
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• 2015

Currently, extreme weather events such as super typhoon, extreme snowfall, and heat wave are frequently occurring all over the world by natural and human caused factors. After industrial growth in the 1970s, earth's temperature has risen sharply. due to greenhouse effect. Global warming can be attributed to gases emitted from using fossil fuel such as average carbon dioxide, perfluorocarbons, nitrous oxide, and methane. Especially, carbon dioxide has the highest composition of about 90%. in the fossile fuel usage emitted gas. Concrete has excellent durability as a building material climate change. However, due to various of physical and chemical environmental effect such as conditions during its curing process, the performance degradation may occur. Carbon dioxide in the atmosphere causes steel corrosion and durability decreases by lowering the alkalinity of concrete. Therefore, in this study, concrete durability performance with respect to carbonation from curing conditions change due to wind speed and sunshine exposure time. Concrete carbonation experiment are performed. using wind speed (0, 2, 4, 6) m/s and sunlight exposure time (2, 4, 6, 8) hrs. Also, performance based evaluation through the satisfaction curve based on the carbonation depth and carbonation rate test results are performed.

• Clinical and Experimental Pediatrics
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• v.49 no.1
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• pp.29-33
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• 2006

Purpose : The aim of this study was to analyze the results and contributing factors of catch-up growth in very low birth weight infants(VLBWI) at the corrected age of 2 years. In addition, we looked for a relationship between the catch-up growth and the development by the bayley scales of infant development II(BSID II). Methods : A retrospective analysis by evaluating medical records was done for the 76 VLBWI whose follow-up was possible up to a corrected age of 2 years, out of the 114 who had been treated in the neonatal intensive care unit during the January of 2000 to December of 2001 at Samsung Cheil Hospital. Based on the Standard Korean Infant's Growth Curve, the catch-up growth group was defined over the 10th percentile of weight at 2 years as the corrected age and the failed catch-up growth group was defined under the 10th percentile. We investigated the clinical factors and courses of each group and compared the scores of the BSID II. Results : The catch-up growth group of the VLBWI was 51 infants and the failed catch-up growth group was 25 infants. In comparison with maternal clinical factors, use of antenatal steroids was significantly higher in the catch-up growth group. In comparisn with clinical factors and courses of VLBWI, two clinical factors were significantly different between the two groups : birth weight and intrauterine growth retardation(IUGR). Numbers of delayed development were increased in the failed catch-up growth group but statistically significant differences could not be observed. Conclusion : The catch-up growth of the VLBWI was affected by the use of antenatal steroids, birth weight and IUGR. No significant differences regarding neurodevelopmental outcome were observed between the catch-up and failed catch-up growth groups.

• Fire Science and Engineering
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• v.34 no.1
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• pp.18-25
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• 2020

In this study, the heat release rate of pipe insulation is analyzed by considering the installation status in accordance with the standards ISO 20632 and NFPA 274. The flame retardation rate was evaluated for six types of test samples: polyethylene foam covered with beaten silver (PE(S)), PE foam tapped (PE(N)), elastomeric closed cell thermal insulation (rubber), Japanese PE foam (PE(J)), Japanese polyurethane foam (PU(J)), and Japanese styro form (ST(J)) by EN 13501-1 and fire growth curve. The results show that PU(J), PE(J), and PE(N) were Class E and ultra-fast, NFPA 274 test standards for Class D and Fast, and PE(S) by ISO 20632 were Class C and Slow, and Rubber and ST(J) were Classes and Low. However, the changes in the time-averaged maximum heat release rate for each test standard (ISO 20632 and NFPA 274) to evaluate the flame retardation rate differed among identical materials. This means that the fundamental study is necessary to analyze the more accurate reasons.

• Journal of Korean Society of Forest Science
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• v.89 no.5
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• pp.634-644
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• 2000

Sterba's theory that stem number maintaining maximum basal area per ha is maximum stem number of a stand, had been applied to data from 103 temporary plots in even-aged Pinus densiflora stands in Kangwon province, Korea and a maximum stem number and mortality model was prepared. DBH growth model which estimates dbh with the independent variables of stem number per ha and dominant height shows the good statistical performance, and explains well differences in dbh growth that would be caused by stem number per ha and dominant height. Basal area model derived from dbh growth model also explains well differences in basal area according to stem number per ha and dominant height. The maximum stem number curve, which is derived from stem number per ha at maximum basal area for dominant height and dbh, represents well the upper range of stem number per ha observed. And maximum stand density index derived from the maximum stem number model for dbh could be used for the index of maximum potential density of a stand. The maximum stem number model and maximum stand density index in this study were not based on stand data with maximum density but based on the temporary data from stands with various density. This maximum stem number model can be applied to the estimation of mortality and maximum potential volume.

• Journal of Animal Science and Technology
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• v.47 no.5
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• pp.905-912
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• 2005

The study was conducted to determine the effects of hormone injection on casting day of antler, velvet antler yield, and blood hormone concentration in elk deer and Sika deer. The study revealed that the casting day of Elk and Sika deer at medroxy progesterone acetate(MPA) injection averaged 21 days after MPA injection, which was earlier 38 and 24 days, respectively, compared control(P<0.01). The regrowth of antler in both Sika deer and Elk occurred in the MPA injection and the duration of antler growth was 2 times longer than control. The total yield of velvet antler of Elk in the control and MPA injection was 7.31 and 10.11kg and the that of sika deer was 1.00 and 1.41kg, respectively. Blood testosterone concentration of Sika deer and Elk was less than 4.0ng/ml for both at the casting and during the antler growing. Blood IGF-1 concentrations of Sika deer and Elk during the antler growing tended to increase with the same as growth curve of antler.

• Asian Pacific Journal of Cancer Prevention
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• v.17 no.2
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• pp.835-838
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• 2016

Background: Lung cancer remains one of the most common cancers in the world, both in terms of new cases (about 13% of total per year) and deaths (nearly one cancer death in five), because of the high case fatality. Errors in lung cancer type or malignant growth determination lead to degraded treatment efficacy, because anticancer strategy depends on tumor morphology. Materials and Methods: We have made an attempt to evaluate effectiveness of machine learning algorithms in the task of lung cancer classification based on gene expression levels. We processed four publicly available data sets. The Dana-Farber Cancer Institute data set contains 203 samples and the task was to classify four cancer types and sound tissue samples. With the University of Michigan data set of 96 samples, the task was to execute a binary classification of adenocarcinoma and non-neoplastic tissues. The University of Toronto data set contains 39 samples and the task was to detect recurrence, while with the Brigham and Women's Hospital data set of 181 samples it was to make a binary classification of malignant pleural mesothelioma and adenocarcinoma. We used the k-nearest neighbor algorithm (k=1, k=5, k=10), naive Bayes classifier with assumption of both a normal distribution of attributes and a distribution through histograms, support vector machine and C4.5 decision tree. Effectiveness of machine learning algorithms was evaluated with the Matthews correlation coefficient. Results: The support vector machine method showed best results among data sets from the Dana-Farber Cancer Institute and Brigham and Women's Hospital. All algorithms with the exception of the C4.5 decision tree showed maximum potential effectiveness in the University of Michigan data set. However, the C4.5 decision tree showed best results for the University of Toronto data set. Conclusions: Machine learning algorithms can be used for lung cancer morphology classification and similar tasks based on gene expression level evaluation.

• Structural Engineering and Mechanics
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• v.81 no.6
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• pp.665-675
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• 2022

The safety problems of giant hydraulic structures such as dams caused by terrorist attacks, earthquakes, and wars often have an important impact on a country's economy and people's livelihood. For the national defense department, timely and effective assessment of damage to or impending damage to dams and other structures is an important issue related to the safety of people's lives and property. In the field of damage assessment and vulnerability analysis, it is usually necessary to give the damage assessment results within a few minutes to determine the physical damage (crack length, crater size, etc.) and functional damage (decreased power generation capacity, dam stability descent, etc.), so that other defense and security departments can take corresponding measures to control potential other hazards. Although traditional numerical calculation methods can accurately calculate the crack length and crater size under certain combat conditions, it usually takes a long time and is not suitable for rapid damage assessment. In order to solve similar problems, this article combines simulation calculation methods with machine learning technology interdisciplinary. First, the common concrete gravity dam shape was selected as the simulation calculation object, and XFEM (Extended Finite Element Method) was used to simulate and calculate 19 cracks with different initial positions. Then, an LSTM (Long-Short Term Memory) machine learning model was established. 15 crack paths were selected as the training set and others were set for test. At last, the LSTM model was trained by the training set, and the prediction results on the crack path were compared with the test set. The results show that this method can be used to predict the crack propagation path rapidly and accurately. In general, this article explores the application of machine learning related technologies in the field of mechanics. It has broad application prospects in the fields of damage assessment and vulnerability analysis.

• Animal Bioscience
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• v.36 no.7
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• pp.1120-1129
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• 2023

Objective: This study aimed to determine the protective efficacy of Buddha's Temple (BT) extract against tert-butyl hydroperoxide (t-BHP)-induced oxidative stress in Gallus gallus chicken embryo fibroblast cell line (DF-1) and its effects on the cell lipid metabolism. Methods: In this experimental study, Gallus gallus DF-1 fibroblast cells were pretreated with BT 10^-7 for 24 hours, followed by their six-hour exposure to t-BHP (100 μM). Water-soluble tetrazolium salt-8 (WST-8) assays were performed, and the growth curve was computed. The intracellular gene expression changes caused by BT extract were confirmed through quantitative polymerase chain reaction (qPCR). Flow cytometry, oil red O staining experiment, and thin-layer chromatography were performed for the detection of intracellular metabolic mechanism changes. Results: The WST-8 assay results showed that the BT pretreatment of Gallus gallus DF-1 fibroblast cell increased their cell survival rate by 1.08%±0.04%, decreased the reactive oxygen species (ROS) level by 0.93%±0.12% even after exposure to oxidants, and stabilized mitochondrial activity by 1.37%±0.36%. In addition, qPCR results confirmed that the gene expression levels of tumor necrosis factor α (TNFα), TIR domain-containing adapter inducing IFN-beta (TICAM1), and glucose-regulated protein 78 (GRP78) were regulated, which contributed to cell stabilization. Thin-layer chromatography and oil red O analyses showed a clear decrease in the contents of lipid metabolites such as triacylglycerol and free fatty acids. Conclusion: In this study, we confirmed that the examined BT extract exerted selective protective effects on Gallus gallus DF-1 fibroblast cells against cell damage caused by t-BHP, which is a strong oxidative inducer. Furthermore, we established that this extract significantly reduced the intracellular ROS accumulation due to oxidative stress, which contributes to an increase in poultry production and higher incomes.