• Journal of Physiology & Pathology in Korean Medicine
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• v.28 no.5
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• pp.520-529
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• 2014

The purpose of this study is to investigate the protective effects of Yukmijiwhang-tang(YM) water extracts against the UVB irradiation on the human keratinocyte HaCaT cells. We observed the effects of YM on the oxidative stress, gene expression of pro-inflammatory cytokine such as TNF-${\alpha}$ and IL-$1{\beta}$, and matrix metalloproteinase-9 in UVB-irradiated HaCaT cells. On the effects of oxidative stress and antioxidant function on the treatment with YM, The activity of xanthine oxidase(XO) was significantly decreased by treatment of YM in all the concentrations(p<0.01). The activity of superoxide dismutase(SOD) and catalase(CAT) was significantly increased by treatment of YM in a dose dependent manner(p<0.05 and p<0.01). DPPH radical was erased by treatment of YM under dose of $500{\mu}g/m{\ell}$ concentration. Treatment of HaCaT cells with YM had also significantly reduced intracellular ROS produced by UVB irradiation in a dose dependent manner(p<0.05, p<0.01, p<0.001). Gelatin zymography assay showed that YM downregulated the MMP-9 activity in UVB-irradiated HaCaT cells. RT-PCR analysis revealed that YM suppressed the expression of IL-$1{\beta}$ and MMP-9 however, it has no effects on the expression of TNF-${\alpha}$ and MMP-3. Our study suggests that Yukmijiwhang-tang exert protective actions on the UVB-irradiated HaCaT cells largely by anti-oxidative and anti-inflammatory processes.

• Molecules and Cells
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• v.26 no.5
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• pp.490-495
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• 2008

Thrombophilia and hypofibrinolysis have been implicated in the pathogenesis of osteonecrosis of the femoral head (ONFH). Tissue factor pathway inhibitor (TFPI), a multivalent protease inhibitor, is an important regulator of the tissue factor-mediated blood coagulation pathway. Mutations of the TFPI gene can increase the risk of thrombin generation and venous thrombosis. The aim of this study was to evaluate the association of TFPI gene polymorphisms with ONFH. All exons and their boundaries of the TFPI gene, including the -1,500 bp promoter region, were directly sequenced in 24 Korean individuals and four sequence variants were identified. These four polymorphisms [-51096 G > A (C-399T), -50984A > G (T-287C), + 24999A > G (Int7 -33T > C), + 37339T > A] were genotyped in 474 ONFH patients and 349 control subjects. The association of genotyped SNPs with ONFH was not found in the present study. The haplotype AAAT of TFPI was significantly associated with total, alcohol-induced, and idiopathic ONFH (p = 0.003, 0.021, and 0.007, respectively), and the haplotype GAAT was significantly associated with total and alcohol ONFH (p = 0.022 and 0.009, respectively). In addition, a new SNP + 37339 T > A in the 3'-UTR of the TFPI gene, was found in the Korean population. To date, this study is the first to show that haplotypes of the TFPI gene are associated with an increased susceptibility for ONFH. The results suggest that genetic variations in TFPI may play an important role in the pathogenesis and risk factors of ONFH.

• Journal of the Korea Institute of Information and Communication Engineering
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• v.21 no.6
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• pp.1106-1112
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• 2017

As the Internet of Things (IOT) is evolving into an industry-wide service and expanded to the concept of Internet of Everything (IoE), services using IoT devices are easily accessible in everyday life. IoT requires more devices to collect information and is expected to increase the number of devices by 50 billion by 2020, and is about the number of devices currently available. Gradually, the number of mobile devices, smart devices, and Internet devices is increasing, and energy resources are required to operate such a large number of Internet devices, and the energy consumed by each device is small. In this paper, we consider the number of devices to be increased and generate a signal irrespective of transmission information so that power other than the energy required for signal transmission is consumed. When transmission information is generated and near to a receiver to receive information, The method to be used as an analysis is designed through experiments.

• Journal of Powder Materials
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• v.16 no.5
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• pp.316-325
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• 2009

Fe based (Fe$_{68.2}$C$_{5.9}$Si$_{3.5}$B$_{6.7}$P$_{9.6}$Cr$_{2.1}$Mo$_{2.0}$Al$_{2.0}$) amorphous powder, which is a composition of iron blast cast slag, were produced by a gas atomization process, and sequently mixed with ductile Cu powder by a mechanical ball milling process. The experiment results show that the as-prepared Fe amorphous powders less than 90 $\mu$m in size has a fully amorphous phase and its weight fraction was about 73.7%. The as-atomized amorphous Fe powders had a complete spherical shape with very clean surface. Differential scanning calorimetric results of the as-atomized Fe powders less than 90 $\mu$m showed that the glass transition, T$_g$, onset crystallization, T$_x$, and super-cooled liquid range $\Delta$T=T$_x$-T$_g$ were 512, 548 and 36$^{\circ}C$, respectively. Fe amorphous powders were mixed and deformed well with 10 wt.% Cu by using AGO-2 high energy ball mill under 500 rpm.

• Journal of The Korean Society of Grassland and Forage Science
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• v.38 no.3
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• pp.150-155
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• 2018

This study was conducted to determine grazing intensity of growing Korean native goats(Capra hircus coreanae) on mountainous pasture. It was carried out to obtain basic information for improvement of mountainous pasture management and establishing feeding system of Korean native goat. A total of 20 goats were grouped by feeding systems [A mountainous pasture grazing group (Concentrated feed of 1.5% body weight, treatment 1, T1, n=10) and a barn feeding group (TMR, treatment 2, T2), n=10] to conduct study from April to September. The average forage productivity of the mountain pasture was $500.9{\pm}61.41kg/ha$. The average dry matter intake in T1 was 0.64 and the calculated grazing intensity was 21 head/ha. In productivity, when the two treatments(T1, T2) were compared, the dry matter intake was about two to three times the difference. The average daily gain per day during the experiment was 63.3 in the mountain pasture and 120 g in barn feeding. When grazing, considering mountainous pasture productivity it is necessary to increase the productivity through proper feeding. The feed costs of black goats raised by grazing on the grassland in the same period showed an average 75% reduction compared to barn feeding. As a result of this study, it can be expected that a considerable reduction of feed costs can be expected in the breeding of Korean native black goat using the mountain pasture.

• Steel and Composite Structures
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• v.16 no.6
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• pp.611-637
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• 2014

A single plate shear connection, or shear tab, is a very popular shear connection due to its merit in ease of construction and material economy. However, problems in understanding the connection behavior, both in terms of strength and ductility, have been well-documented. Suggestions or design model for single plate connections in AISC Design Manual have been altered several times, with the latest edition settling down to giving designers pre-calculated design strength tables if the connection details agree with given configurations. Results from many full-scale tests and finite element models in the past suggest that shear strength of a bolt group in single plate shear connections might be affected by yield strength of plate material; therefore, this research was aimed to investigate and clarify effects of plate yield strength and thickness on shear strength of the bolt group in the connections, including the validity of using a plate thickness/bolt diameter ratio ($t_p/d_b$) in design, by using finite element models. More than 20 models have been created by using ABAQUS program with 19.0- and 22.2-mm A325N bolts and A36 and Gr.50 plates with various thicknesses. Results demonstrated that increase of plate thickness or plate yield strength, with the $t_p/d_b$ ratio remained intact, could significantly reduce shear strength of the bolt group in the connection as much as 15 percent. Results also confirmed that the $t_p/d_b$ ratio is a valid indicator to be used for guaranteeing strength sufficiency. Because the actual ratio recommended by AISC Design Manual is $t_p/d_b$ + 1.6 (mm) for connections with a number of bolts less than six and plate yield strength in construction is normally higher than the nominal value used in design, it is proposed that shear strength of a bolt group in single plate connections with a number of bolts equal or greater than seven be reduced by 15 percent and the $t_p/d_b$ ratio be limited to 0.500.

• Transactions of the Korean Society for Noise and Vibration Engineering
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• v.25 no.7
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• pp.462-469
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• 2015

This study was carried out to examine characteristics of various acoustic indicators evaluating speech intelligibility such as reverberation time(T₃₀), D₅₀, C₅₀ and speech transmission index(STI) in Korean elementary school classrooms. Results showed that mean T₃₀ at middle frequencies(500 Hz to 2000 Hz) measured in 9 classrooms was about 0.75 s, which exceeds a regulation specified on American National Standards(ANSI); 0.60 s. Mean D₅₀, C₅₀ and STI were 60 % to 66 %, +2 dB to +3 dB, and 0.65, respectively. The maximum difference in D₅₀ and C₅₀ according to different receiver points in a classroom was 13 % and 2.5 dB, while the maximum difference in T₃₀ was 0.03 s. Whereas STI measured in classrooms has relatively low correlation with other indicators, correlation between D₅₀ and C₅₀ was high, R²=.9964. In addition, T₃₀ and C₅₀ were fitted well as logarithmic regression curve with R²=.9610. It was +3.73 dB in C₅₀ and 68 % in D₅₀ which are the value corresponding to 0.60 s in T₃₀ on this curve.

• Biomolecules & Therapeutics
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• v.9 no.4
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• pp.285-290
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• 2001

Bioequivalence of two acetyl-1-carnitine tablets, test product (Carnitile tablet: Hanmi Pharm. Co., Ltd.) and reference product (Nicetil $e^{R}$ tablet: Dong-A Pharm. Co., Ltd.), was evaluated according to the guide- lines of Korea Food and Drug Administration (KFDA). Twenty-six healthy volunteers were divided randomly into two groups and administered the drug orally at the dose of 500 mg as acetyl-1-carnitine in a 2$\times$2 crossover study. Blood samples were taken at predetermined time intervals for 12 hours and the plasma concentration of acetyl-1-carnitine was determined using HPLC by derivatization with p-bromophenacyl bromide. The pearmacokinetic parameters (AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$) were calculated and ANOVA was utilized for the statistical analysis of parameters. The apparent differences of these parameters between two drugs were less than 20% (i.e., 1.26,-5.08 and 8.59% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The powers (1-$\beta$) for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, and Tmax were over 0.9. Minimal detectable difference ($\Delta$) at $\alpha$=0.05, 1-$\beta$=0.8 were less than 20% (i.e.,7.31, 14.88 and 11.77% for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). The confidence intervals ($\delta$) for these parameters were also within $\pm$ 20% (i.e.,-3.03$\leq$$\delta$$\leq$5.54, -13.80$\leq$$\delta$$\leq$3.64 and 1.69$\leq$$\delta$$\leq$15.48 for AU $C_{0-}$12h/ $C_{max}$ and $T_{max}$, respectively). These results satisfied the criteria of KFDA guideline for bioequivalence, indicating Carnitile bioequivalent to Nicetil $e^{R}$ .TEX>$^{R}$ .> R/ . R/ .

• Journal of Korea Foundry Society
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• v.15 no.5
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• pp.469-476
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• 1995

The effects of Cr, Mo or B additions were investigated on $B2{\leftrightarrow}DO_3$ structural transition temperature $(T_C)$ and mechanical properties of Fe-28at.%Al. The raw materials were arc-melted in vacuum and then subjected to the following heat-treatments to maximize the $DO_3$ ordered structure : $1000^{\circ}C/7days$, slowly cooled to $500^{\circ}C$ and then held for 5 days. In the effect on the grain refinment, the addition of alloying element B was the most effective. The addition of Cr or Mo had little effect. When 1at.%Mo was added, $T_c$ increase about $30^{\circ}C$, but Cr had a very little effect on $T_c$. On the contrary, when B was added, $T_c$ was apt to come down minutely. In the additional effect of alloying element on the mechanical properties, Cr was apt to decrease the microvickers hardness and yield strength, Mo and B didn't have much effect. In the case of compressure strength test, the effect of the environment on the yield strength was contrary to the result of the tensile strength test.

• Journal of Power System Engineering
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• v.22 no.1
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• pp.79-86
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• 2018

Many countries have conducted extensive studies for biomass co-firing to enhance the durability of reactor on high-temperature corrosion. However, due to the complicated mechanisms of biomass co-firing, there have been limitations in accurately determining the current state of corrosion and predicting the potential risk of corrosion of power plant. In order to solve this issue, this study introduced Lab-scale corrosion system to analyze the corrosion characteristics of the A213 T91 material under the biomass co-firing conditions. The corrosion status of the samples was characterized using SEM/EDS analysis and mass loss measurement according to various biomass co-firing conditions such as corrosion temperature, $SO_2$ concentration, and corrosion time. As a result, the corrosion severity of A213 T91 material was gradually increased with the increase of $SO_2$ concentration in the reactor. When $SO_2$ concentration was changed from 0 ppm to 500 ppm, both corrosion severity and oxide layer thickness were proportionally increased by 15% and 130%, respectively. The minimum corrosion was observed when the corrosion temperature was $450^{\circ}C$. As the temperature was increased up to $650^{\circ}C$, the faster corrosion behavior of A213 T91 was observed. A213 T91 was observed to be more severely corroded by the effect of chlorine, resulting in faster corrosion rate and thicker oxide layer. Interestingly, corrosion resistance of A213 T91 tended to gradually decrease rather than increases as the oxide layer was formed. The results of this study is expected to provide necessary research data on boiler corrosion in biomass co-firing power plants.