• Journal of Nutrition and Health
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• v.49 no.5
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• pp.367-377
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• 2016

Purpose: This study analyzed the degree of job stress and caffeine intake in workers in industrial positions in order to determine the relationships between job stress and caffeine intake. Methods: For this purpose, this study conducted a survey targeting 361 blue collar workers working for K manufacturing company, Gwangju. Results: The total score for job stress in subjects was $72.7{\pm}6.8points$/100points. According to job stress, subjects were categorized as follows: Q1 for the group who had the least stress; Q2 for the group who had little stress; Q3 for the group who had a lot of stress, and Q4 for the group who had the most stress. As for the effects of caffeine on health, 57.1% thought that caffeine is helpful and not harmful if taken properly while 17.3% responded that less caffeine consumption is better. Daily intake of caffeine according to stress was presented as: $172.0{\pm}85.3mg$ in Q1, $179.0{\pm}83.7mg$ in Q2, $187.9{\pm}81.4mg$ in Q3, and $214.2{\pm}147.3mg$ in Q4 (p < 0.05). The percentages of caffeine consumption compared to the daily safe limit in subjects were: $43.0{\pm}21.3$, $44.8{\pm}20.9$, $47.1{\pm}20.4$, and $53.6{\pm}36.8%$ in Q1, Q2, Q3, and Q4, respectively (p < 0.05). Adverse effects such as nausea or vomiting from caffeine were most common in Q4 (p < 0.05). Conclusion: As a result, higher stress in blue collar workers working for K manufacturing company was associated with more caffeine consumption. Groups with a lot of stress (Q4) consumed approximately 50% of daily safe limit of caffeine. Considering the results above, this study suggests that further research on more precise caffeine intake and its effects is needed.

• Korean Journal of Environment and Ecology
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• v.34 no.6
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• pp.573-588
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• 2020

The study investigated the forest vegetation structure of Kongju National University Forests in the vicinity of Seokjangri-dong to provide the information needed for efficient use and management. It conducted a Z-M phytosociological vegetation survey in 60 quadrate plots in August 2019 and generated the actual vegetation map by analyzing the physiognomic community classification and mean importance value. The physiognomic community classification showed five vegetation community types: Quercus acutissima community, Pinus densiflora community, Quercus variabilis community, Pinus rigida community, and Quercus serrata community. The relative importance value in the Q. acutissima community was 31.4% for Q. acutissima, 9.6% for Prunus spp., and 9.0% for Q. variabilis. In the P. densiflora community, it was 24.9% for P. densiflora, 12.4% for Q. acutissima, and 11.5% for Q. serrata. In the Q. variabilis community, it was 25.3% for Q. variabilis, 9.8% for Prunus spp., and 8.5% for Q. acutissima. In the P. rigida community, it was 28.4% for P. rigida 28.4%, 10.0% for Q. acutissima, and 9.3% for P. densiflora. In the Q. serrata community, it was 27.0% for Q. serrata, 11.3% for Q. aliena, and 11.5% for Styrax japonica. The actual vegetation map based on the uppermost dominant species to identify the forest vegetation's spatial distribution characteristics indicated that the natural vegetation covered the most with 87.5%, the number of vegetation patches was 87, and the average area per patch was 1.46ha.

• Honam Mathematical Journal
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• v.38 no.1
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• pp.9-15
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• 2016

In this paper, the authors establish some double inequalities concerning the (q, k)-deformed Gamma function. These inequalities emanate from certain problems of traffic flow. The procedure makes use of the integral representation of the (q, k)-deformed Gamma function.

• Clean Technology
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• v.25 no.3
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• pp.231-237
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• 2019

The BOD removal efficiency according to HRT of the continuous inflow SBR process was decreased from 92.1 ~ 96.0% at HRT 9 ~ 15 h to 86.9 ~ 90.7% at HRT 6 h, but a stable removal efficiency was shown up to HRT 6 h. The T-N removal rate was decreased to 80.1 ~ 87.9% at HRT 12 ~ 15 h, to 71.9 ~ 87.0% at HRT 9 h, and to 60.1 ~ 65.7% at HRT 6 h. As a result of the test of removing organic matter and nitrogen, the optimum HRT of the continuous inflow SBR reactor is determined as 9 h. The TCODcr removal efficiency was 88.4 ~ 96.0% and the TBOD removal efficiency was 92.1 ~ 98.1% as a result of examination of organic matter removal efficiency according to a change in the recycling rate (1 ~ 5Q) at HRT 9 h, suggesting that the a change in the recycling rate has a minimal effect on the removal of organic matter. The T-N removal efficiency was 70.3 ~ 80.4% at 1 ~ 2Q, 77.2 ~ 85.6% at 3Q and 61.5 ~ 80.8% at 4 ~ 5Q according to a change in the recycling rate. The TP removal efficiency was reduced to 75.0 ~ 84.6% at 1 ~ 4Q and to 63.3 ~ 72.4% at 5Q. This is presumably because the release and ingestion of phosphorus (P) by microorganisms is not performed smoothly at 5Q or more. Therefore, the optimum recycling rate for removing organic matter and nutrients was found to be 3Q.

• YAKHAK HOEJI
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• v.41 no.5
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• pp.638-646
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• 1997

The steroid 9${alpha}$-hydroxylase activity has been detected in cytosol fraction, $100,00{\times}g$ supernatant of cell free extract of Mycobacterium fortuitum. The activity was not linear with protein concentration in the assay suggesting 9${alpha}$-hydroxylase is a multicomponent enzyme. The 9${alpha}$-hydroxylase system was partially purified through fractional saturation of ammonium sulfate, strong anion exchange (Mono Q) column chromatography, gel filtration (Superose 12) column chromatography, and testosterone affinity gel chromatography. Ammonium sulfate 50~60% saturated fraction of the cytosol gave 9${alpha}$-hydroxylase activity. For further purification, the half-saturated ammonium sulfate fraction was applied to Mono Q, Superose 12, or affinity gel column. The purification factors of 9${alpha}$-hydroxylase containing fraction after Mono Q, Superose 12, and affinity gel chromatography was 13, 11, and 17 respectively.

• Transactions of the Korean Society of Mechanical Engineers A
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• v.35 no.3
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• pp.251-257
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• 2011

This paper deals with the statistical properties of parameters B and q in the creep crack growth rate (CCGR) law, da/dt=B$(C^*)^q$, in Mod. 9Cr-1Mo (ASME Gr.91) steel which is considered a candidate materials for fabricating next generation nuclear reactors. The CCGR data were obtained by creep crack growth (CCG) tests performed on 1/2-inch compact tension (CT) specimens under an applied load of 5000N at a temperature of $600^{\circ}C$. The CCG behavior was analyzed statistically using the empirical equation between CCGR, da/dt and the creep fracture mechanics parameter, $C^*$. The B and q values were determined for each specimen by the least-squares fitting method. The probability distribution functions for B and q were investigated using normal, log-normal, and Weibull distributions. As far as this study is considered, it can be appeared that B and q followed the log-normal and Weibull distributions. Moreover, a strong positive linear correlation was found between B and q.

• Journal of the Earthquake Engineering Society of Korea
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• v.3 no.1
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• pp.67-74
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• 1999

In this study, coda Q has been determined by the single scattering model in the Kyeongsang Basin region using the decay of the amplitudes of coda waves on bandpass-filtered seismograms of local microearthquakes in the frequency range 1.5~18 Hz. Reported frequency dependence of Q is of the form $Q_C=Q_O^n$$(83.9{ll}Q_0{ll}155.9,;0.76{ll}n{ll}1.05$. Considering a model incorporating both scattering and intrinsic attenuation, and assuming that the attenuation is entirely due to the scattering loss, the minimum mean free paths are about 51~56 km and the coefficients of inelastic attenuation(${\gamma}$) are between 0.0093 and 0.0098 were found. Earthquake-station paths pass through the fault zone show high attenuation and strong frequency dependency compared to other ones.

• Journal of the Institute of Electronics and Information Engineers
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• v.49 no.9
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• pp.145-154
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• 2012

This paper proves that multi-port junction-based direct receivers (MPDRs) can regenerate I- and Q-channel signals accurately by using conventional I/Q mismatch compensation. This proof enables MPDRs to be integrated into existing RFIC based systems without additional digital signal processing. This paper analyzes the relationship between accuracy of I/Q regeneration parameters and degree of I/Q mismatch, and shows that the estimation results and the simulation results are almost the same.

• Journal of the Korean earth science society
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• v.27 no.4
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• pp.475-485
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• 2006

The physical properties of the central and southwestern crust of South Korea were estimated by comparing values of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ in the Kimcheon and Mokpo areas. In order to get ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ values, seismic data were collected from two stations of the KIGAM network (KMC and MUN) and four stations of the KMA network (CPN, KUC, MOP, and WAN). An extended coda-normalization method was applied to these data. Estimates of ${Q_P}^{-1}\;and\;{Q_S}^{-1}$ show variations depending on frequency. As frequencies vary from 3 Hz to 24 Hz, the estimates decrease from $(1.4{\pm}3.9){\times}10^{-3}\;to\;(2.3{\pm}3.5){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(1.8{\pm}1.3){\times}10^{-3}\;to\;(1.9{\pm}1.5){\times}10^{-4}\;for\;{Q_S}^{-1}$ in central South Korea, and $(5.9{\pm}4.8){\times}10^{-3}\;to\;(2.2{\pm}3.8){\times}10^{-4}\;for\;{Q_P}^{-1}\;and\;(0.5{\pm}2.8){\times}10^{-3}\;to\;(1.8{\pm}1.6){\times}10^{-4}\;for\;{Q_S}^{-1}$ in southwestern South Korea. According that a frequency-dependent power law is applied to the data, the best fits of ${Q_P}^{-1}\;and\;{Q_S}^{-1}\;are\;0.003f^{-0.49}\;and\;0.005f^{-1.03}$ in central South Korea, and $0.026f^{-1.47}$ and $0.001f^{-0.49}$ in southwestern South Korea, respectively. These values almost correspond to those of seismically stable regions although ${Q_P}^{-1}$ values of southwestern South Korea are a little high due to lack of data used.

• The KIPS Transactions:PartD
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• v.9D no.1
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• pp.153-160
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• 2002

This paper describes the design and implementation of library for real-time operating system Q+, that was developed for the internet appliance. The library in the real-time operating system should be defined according to the standard interface and support the functions that are adequate to the real-time application. To ensure the compatibility between application programs, the Q+ library follows industrial and international standards, such as POSIX.1, ISO 7942 GKS. And, to support the Q+ application, library provides C standard functions, graphic/window functions, network functions, security support functions, file system functions. The Q+ library was implemented using the Q+ kernel, Digital TV set-top box, and KBUG debugging tool.