• 한국노년학
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• v.31 no.4
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• pp.1015-1027
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• 2011

The aim of this study is to understand the types of subjective causal perception of Hwa-byung among the Korean elderly men and reveal the characteristics of each type. Q-methodology was used to analyze each individual participant's subjectivity on Hwa-byung. A total of 25 Korean elderly men arranger 31 pre-selected Q-statement cards on a 9-point scale, shaping the cards' pile into a normal distribution. Then, the data from the arranged cards were analyzed using the QUANL PC Program. Data analysis showed that participants perceived four situation to cause Hwa-byung: Lack of sympathetic relationships, Incompetence and misfortune of their own, Weakness due to aging, and Regrets about the past to life. The analysis of the different types will be able to provide material on how to specifically offer psychological support to the Korean elderly men.

• Korean Journal of Agricultural and Forest Meteorology
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• v.10 no.4
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• pp.141-148
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• 2008

This study was conducted to investigate the photosynthetic responses of four Oak species (Quercus mongolica, Q. serrata, Q. acutissima and Q. variabilis) by shading treatment. We investigated light response curve, photosynthesis (A)-intercellular $CO_2$ concentration (Ci) curve, leaf growth and chlorophyll content at the level of 35, 55 and 75% shading treatments and under the full sunlight. In our results, Q. variabilis and Q. acutissima showed increased leaf growth, chlorophyll content and net apparent quantum yield but reduced chlorophyll a/b and carboxylation efficiency under the low light intensity. Therefore, light absorption and light utilization efficiency were improved under the low light intensity. Q. mongolica showed the similar responses that Q. variabilis and Q. acutissima showed, but net apparent quantum yield was reduced. The effects of shading treatment on Q. serrata were lower than those of other three species.

• 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.

• Korean Journal of Mathematics
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• v.24 no.4
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• pp.681-691
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• 2016

In this note, we consider a generalized Fibonacci sequence {$q_n$}. We give a generating matrix for {$q_n$}. With the aid of this matrix, we derive and re-prove some properties involving terms of this sequence.

• Bulletin of the Korean Mathematical Society
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• v.50 no.4
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• pp.1145-1156
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• 2013

In this paper, a kind of modified $q$-Bernstein-Schurer operators is introduced. The Korovkin type statistical approximation property of these operators is investigated. Then the rates of statistical convergence of these operators are also studied by means of modulus of continuity and the help of functions of the Lipschitz class. Furthermore, a Voronovskaja type result for these operators is given.

• Honam Mathematical Journal
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• v.45 no.4
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• pp.689-700
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• 2023

In this note, we establish a new subfamily of spirallike functions by making use of a generalized q-integral operator. We examine characterization rule for functions which are member of this subclass. We further obtain coefficient estimate, subordination results and integral mean inequalities for functions in this class. The Fekete-Szegö inequalities are also derived.

• Current Optics and Photonics
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• v.4 no.2
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• pp.127-133
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• 2020

We successfully constructed a passively Q-switched Yb:YAG laser ignitor pumped by a diode laser with low power and long pulse width. To the best of our knowledge, this is the first study to achieve a quasi-MW output power from an optimized Q-switch Yb:YAG laser ignitor by using a pumping diode laser module emitting at under a power of 23 W. The output pulse energy of our optimized laser is 0.98 mJ enclosed in a 1.06 ns pulse width, corresponding to a peak power of 0.92 MW.

• Proceedings of the KSME Conference
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• 2002.08a
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• pp.623-626
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• 2002

The object of present study is to find the flow characteristics of centrifugal turbomachinery according to the volute shape change. The experiments were carried out for two model; volute-A designed by free vortex conditions and volute-B designed for use in high mass flow rate conditions using the volute-A test results, Flow measurements were taken in shrouded impeller with 12 backward type blades by using a five-hole pilot-tube and carried out in 4 flow rate, $Q/Q_d\;=0,43,\;1.0,\;1.27,\;1,47$, respectively, For volute-B, we found that pressure distribution was more uniform at high flow rate and from $Q/Q_d\;:\;0,43\;to\;Q/Q_d\;:\;1,20$, losses decreased and efficiency increased compare with volute-A.

• Nutrition Research and Practice
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• v.4 no.4
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• pp.311-316
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• 2010

The purpose of this study was to investigate the relationship between birth weight and appetite related hormones, insulin resistance, and antioxidant status in overweight children aged 9-10 years. Thirty-four healthy overweight children (18 boys, 16 girls) were evaluated with respect to anthropometric measurement, lipid profiles, leptin, ghrelin, glucose, insulin, C-peptide, lipid soluble vitamins, and antioxidant enzyme activities. I found that birth weight was negatively correlated with insulin resistance parameters, ghrelin, and coenzyme Q10 levels. There was a significant positive correlation between present BMI and leptin level, while a negative correlation was noted between the BMI and $\alpha$-tocopherol and lycopene levels. When total subjects were classified into three groups by tertiles of birth weight, the lowest tertile of birth weight (LTB) group showed higher levels of fasting glucose, HOMA-IR, and ghrelin level than the highest tertile of birth weight (HTB) groups. On the other hand, HTB group showed an increased oxidative stress (decreased coenzyme Q10 level and catalase activity) compared to the LTB group. In conclusion, plasma ghrelin level might play an important role in accelerated growth in overweight children with LTB. Increased insulin resistance is present in overweight children with LTB, while decreased coenzyme Q10 and catalase activity in overweight children with HTB. These results suggest that birth weight might be an important factor for determination of treatment for obesity related complications in childhood obesity.

• The Korean Journal of Nuclear Medicine Technology
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• v.21 no.2
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• pp.31-36
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• 2017

Purpose Recently, the performance of PET/CT scanner has been improved and various techniques have been developed to increase the image quality such as Sensitivity and Resolution. The purpose of this study is to evaluate the usefulness of Q.Clear (a fully convergent iterative reconstruction) technique of GE Discovery IQ equipment to enhance the image quality. Materials and Methods All scans were acquired by Discovery IQ (GE Healthcare, MI, USA). In NEMA IEC Body Phantom test, Background to Hot-sphere (10 mm, 13 mm, 17 mm, 22 mm) ratio was 1:4 and scan time was 3 minutes. The images were reconstructed by VPHDs (VUE Point High-Definition + SharpIR) and Q.Clear to evaluate each Contrast. We injected 18F-FDG 187 M㏃ to PET/SPECT Performance Phantom. And then it was scanned for 4 minutes to evaluate Resolution and Uniformity. T-test statistical analysis was performed on SUVmax of small lesions less than 2 cm in 100 clinical patients regardless of disease type. Results In the NEMA IEC Body Phantom, the Contrast was $63.6{\pm}5.7%$ (VPHDs) and $75{\pm}4.8%$ (Q.Clear). In the PET/SPECT Performance Phantom, the Resolution was 9.2 mm (VPHDs) and 7.3 mm (Q.Clear). Uniformity of Q.Clear was 10.8% better than VPHDs. T-test statistic of the clinical patients showed a significant difference of p value of 0.021. Conclusion Both the phantom test and the clinical results showed that the quality of the image was improved in Q.Clear was applied. The SUVmax was highly measured in Q.Clear and the lesions were clearly distinguished visually. Therefore Q.Clear can be useful in various aspects such as dose-reduction, patients evaluation and image analysis.