• Journal of Plant Biology
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• v.37 no.1
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• pp.37-42
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• 1994

Correlative changes between photosynthetic O2 exchange rates and room temperature Chl fluorescence were investigated in wheat (Triticum aestivum L.) chloroplasts treated with high temperature for 5 min. With increasing treatment temperature, photosynthetic O2 evolution rate mediated by PSII was decreased, showing 50% inhibition at 38$^{\circ}C$ (I50). But PSI activity measured by O2 uptake rates was stimulated as a function of increasing temperature. Dark level fluorescence (Fo)-temperature (T) analysis showed that fluorescence rising temperature (Tr), critical temperature (Tc), and peak temperature (Tp) was 38, 43, and 52$^{\circ}C$, respectively. Quenching analysis of Chl fluorescence showed that both the oxidized fraction of plastoquinone (qQ) and degree of thylakoid membrane energization (qNP) increased up to 4$0^{\circ}C$ and then declined dramatically. These results suggest that Tr is correlated with temperature showing a 50% of inhibition of photosynthesis and under mild high temperature stress, qNP is worth regarding as indicator for heat-induced damage of photosynthesis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.15 no.1
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• pp.198-208
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• 2011

When a structure which has relatively low load constructs on soft clay, the bearing capacity of the ground will be improved by sand overlying clay. In this condition, verifying the bearing capacity is difficult from the P.B.T etcetera in the in-situ. So, it is needed to estimate precise bearing capacity in the design process. In this study, 2-dimensional chamber tests and FEM analyses are conducted to evaluate behavior of bearing capacity for shallow foundations on a sand overlying clay. Because depth ratio H/B and bearing capacity ratio $q_c/q_s$ are selected as main factors, height of a sand, undrained shear strength of a clay and width of a loading are designated as variables. Results from chamber tests are very similar with those of FEM analyses. And it shows that punching shear mechanism is more suitable than the equation of Okamura et al.(1998). To make continual application of load spread mechanism, the equivalent load spread angle is proposed for H/B and $q_c/q_s$. Also, the linear regression equation of critical depth ratio Hf is suggested for $q_c/q_s$.

• Journal of Nutrition and Health
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• v.55 no.1
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• pp.120-140
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• 2022

Purpose: The purpose of the study was to investigate whether adherence to the Korea Healthy Eating Index (KHEI) was associated with metabolic syndrome and risk markers. Methods: The participants included 8,345 adults, aged 20-59 years, who took part in the 7th Korea National Health and Nutrition Examination Survey (KNHANES). The data were analyzed using a complex-sample t-test, the Rao Scott χ²-test, and logistic regression analysis on the SPSS v. 26.0 software. The participants were divided into four groups by quartiles of KHEI scores. Results: The average KHEI score was 61.06 points out of 100, and the women's score (62.50 points) was significantly higher than that of men (59.63 points). The KHEI quartiles status showed significant differences by age (p < 0.001), household income (p < 0.001), smoking status (p < 0.001), and food security. Specifically, the KHEI quartiles in the men showed significant differences in education (p < 0.001) and economic activity (p < 0.001) whereas those of women showed significant differences in alcohol-consumption (p < 0.001), depression (p < 0.01) and eating-out (p < 0.001). As the KHEI scores increased, the proportion of subjects with an energy intake below the estimated energy requirement (EER) was lower, and significantly better levels of intake were observed for carbohydrate, protein, vitamin C, calcium, vitamin B₁, vitamin B₂, and niacin. The incidence of the metabolic syndrome risk factors, hypertriglyceridemia and hyperglycemia for men and hypertension, and hyperglycemia for women showed significant differences. The KHEI scores were inversely associated with abdominal obesity, hypertriglyceridemia, low high-density lipoprotein cholesterol, hyperglycemia, hypertension, and metabolic syndrome. Conclusion: Based on these results, we conclude that higher adherence to the KHEI was associated with lower metabolic syndrome risk factors and incidence of the metabolic syndrome.

• Clean Technology
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• v.18 no.4
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• pp.366-372
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• 2012

Three acrylic copolymers containing tris(8-hydroxyquinoline) aluminum (AlQ3) pendant group (25 wt%), acrylateco-HEMA-$AlQ_3$ (25 wt%), were successfully synthesized by free radical polymerization from acrylates [methyl methacrylate (MMA), acrylonitrile (AN) or 2-hydroxyethyl methacrylate (HEMA)] with HEMA functionalized with AlQ3 pendant groups (HEMA-p-$AlQ_3$). The glass transition temperatures ($T_g$) of MMA-co-HEMA-p-$AlQ_3$ (copolymer 1), AN-co-HEMA-p-$AlQ_3$ (copolymer 2) and HEMA-co-HEMA-p-$AlQ_3$ (copolymer 3) were found to be 158, 150 and $126^{\circ}C$, respectively. They have good thermal stability: a very desirable feature for the stability of OLEDs. Their solubility, thermal properties, UV-visible absorption and photoluminescence behaviors were investigated. They were found to be soluble in various organic solvents such as tetrahydrofuran (THF), dimethylformamide (DMF), toluene and chloroform. It was also found that the UV-visible absorption and photoluminescence behaviors of these copolymers were similar to those of pristine $AlQ_3$. Green organic light-emitting diodes (OLEDs) have also been fabricated using these copolymers as light emission/electron transport components obtained easily by spin coating, and their current density voltage (J-V) curves were compared. The OLED device of the copolymer 3 had the lowest turn-on voltage of about 2 V compared to other copolymer types devices.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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• 2008.11a
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• pp.387-388
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• 2008

This paper presents the design approach and test results of the Q-band precision subminiature coaxial adaptor based on transmission line theory using multi-step impedance and air-holes to increase its cutoff frequency. In order to increase the frequency performance, the adaptor is designed with hooked structure, fixing step, multi-air-holes, and outer conductor. The return loss increments due to the hooked structure and multi air-holes are minimized to 2 dB and 1.5 dB, respectively. A VSWR(Voltage Standing Wave Ratio) of <1.2 is obtained from DC to 40 GHz, while guaranteeing the durability of the adaptor from room-temperature$(25^{\circ}C)$ to $120^{\circ}C$.

• Bulletin of the Korean Mathematical Society
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• v.33 no.1
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• pp.39-44
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• 1996

Throughout this paper $Z^p, Q_p$ and C_p$ will denote the ring of p-adic rational integers, the field of p-adic rational numbers and the completion of the algebraic closure of $Q_p$, respectively. Let $v_p$ be the normalized exponential valuation of $C_p$ with $$\mid$p$\mid$_p = p^{-v_p (p)} = p^{-1}$. We set $p^* = p$ for any prime p > 2 $p^* = 4 for p = 2$.

• Journal of Ecology and Environment
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• v.41 no.6
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• pp.165-172
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• 2017

Background: This study investigated the temporal variation in soil $CO_2$ efflux and its relationship with soil temperature and precipitation in the Quercus glauca and Abies koreana forests in Jeju Island, South Korea, from August 2010 to December 2012. Q. glauca and A. koreana forests are typical vegetation of warm-temperate evergreen forest zone and sub-alpine coniferous forest zone, respectively, in Jeju island. Results: The mean soil $CO_2$ efflux of Q. glauca forest was $0.7g\;CO_2\;m^{-2}\;h^{-1}$ at $14.3^{\circ}C$ and that of A. koreana forest was $0.4g\;CO_2\;m^{-2}\;h^{-1}$ at $6.8^{\circ}C$. The cumulative annual soil $CO_2$ efflux of Q. glauca and A. koreana forests was 54.2 and $34.2t\;CO_2\;ha^{-1}$, respectively. Total accumulated soil carbon efflux in Q. glauca and A. koreana forests was 29.5 and $18.7t\;C\;ha^{-1}$ for 2 years, respectively. The relationship between soil $CO_2$ efflux and soil temperate at 10 cm depth was highly significant in the Q. glauca ($r^2=0.853$) and A. koreana forests ($r^2=0.842$). Soil temperature was the main controlling factor over $CO_2$ efflux during most of the study period. Also, precipitation may affect soil $CO_2$ efflux that appeared to be an important factor controlling the efflux rate. Conclusions: Soil $CO_2$ efflux was affected by soil temperature as the dominant control and moisture as the limiting factor. The difference of soil $CO_2$ efflux between of Q. glauca and A. koreana forests was induced by soil temperature to altitude and regional precipitation.

• Journal of IKEEE
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• v.19 no.1
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• pp.110-117
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• 2015

In this paper, a novel trench power MOSFET using a Separate-W-gated technique MOSFET (SWFET) is proposed. Because the SWFET has a very low $Q_{GD}$ compared to other forms of technology, it can be applied to high-speed power systems. The results found that the SWFET-applied $Q_{GD}$ was decreased by 40% when compared to simply using the more conventional trench gate MOSFET. $C_{ISS}$ (input capacitance : $C_{GS}+C_{GD}$), $C_{OSS}$ (output capacitance : $C_{GD}+C_{DS}$) and $C_{RSS}$ (reverse recovery capacitance : $C_{GD}$) were improved by 24%, 40%, and 50%, respectively. The switching characteristics of the inverter circuit shows a 24.9% enhancement of reverse recovery time, and the power efficiency of the DC-DC buck converter increased by 14.2%. In addition, the proposed SWFET does not require additional process steps and There was no degradation in the electrical performance of the current-voltage and on-resistance.

• Journal of information and communication convergence engineering
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• v.7 no.4
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• pp.469-474
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• 2009

Q-algorithm is proposed at EPC global Class-1 Generation-2 RFID systems to determine the frame size of next query round. In Q-algorithm, the reader calculates the frame size without estimating the number of tags. But, it uses only the slot conditions: empty, success, or collision. Therefore, it wastes less computational cost and is simpler than other algorithms. However, the constant parameter C value, which is used for calculating the next frame size, is not optimized. In this paper, we propose the optimized C values of Q-algorithm according to the number of tags within the identification range of reader through a lot of computer simulations.

• Journal of applied mathematics & informatics
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• v.30 no.3_4
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• pp.455-462
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• 2012

The cyclic group $Cn={\langle}(12{\cdots}n){\rangle}$ acts on the set ($^{[n]}_k$) of all $k$-subsets of [$n$]. In this action of $C_n$ the number of orbits of size $d$, for $d|n$, is $$O^{n,k}_d=\frac{1}{d}\sum_{\frac{n}{d}|s|n}{\mu}(\frac{ds}{n})(^{n/s}_{k/s})$$. Stanton and White[7] generalized the above identity to construct the orbit polynomials $$O^{n,k}_d(q)=\frac{1}{[d]_{q^{n/d}}}\sum_{\frac{n}{d}|s|n}{\mu}(\frac{ds}{n})[^{n/s}_{k/s}]{_q}^s$$ and conjectured that $O^{n,k}_d(q)$ have non-negative coefficients. In this paper we give a combinatorial proof for the positivity of coefficients of the orbit polynomial $O^{n,3}_d(q)$.