• Bulletin of the Korean Chemical Society
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• v.35 no.10
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• pp.2963-2968
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• 2014

We report synthesis and photovoltaic properties of two new conjugated copolymers, PCPDTQxF and PDTSQxF, with 6,7-difluoro-2,3-dihexylquinoxaline unit prepared by Stille coupling reaction. The advantage of 6,7-difluoro-2,3-dihexylquinoxaline based copolymer are high PCEs due to lower HOMO energy level, long wavelength absorption and high hole mobility. The solid films of PCPDTQxF and PDTSQxF showed absorption bands with maximum peaks at about 623 and 493 nm and the absorption onsets at 711 and 635 nm, corresponding to band gaps of 1.74 and 1.95 eV, respectively. The oxidation onsets of the PCPDTQxF and PDTSQxF polymers were estimated to be 0.68 and 0.95 V, which correspond to HOMO energy levels of -5.48 and -5.75 eV, respectively. The PDTSQxF has lower HOMO energy level as compared to PCPDTQxF to lead higher $V_{OC}$ value. The device comprising PCPDTQxF:PCBM (1:2) dissolved to a concentration of 1 wt % in ODCB showed $V_{OC}$ value of 0.62 V, $J_{SC}$ value of $1.14mA/cm^2$, and FF of 0.35, which yielded PCE of 0.25%.

• Journal of the Korean Society for Precision Engineering
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• v.17 no.1
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• pp.145-152
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• 2000

X-ray diffraction method detects change of crystal lattice distance under material surface using diffraction angle 2$\theta$. This technique can be applied to the behavior on slip band and micro crack due to material degradation. The relation between half-value breadth and number of cycle has three stages which constitute rapid decrease in initial number of cycles, slight decrease in middle number of cycles and rapid decrease in final number of cycles. The ratio of half-value breadth takes a constant value on B/B$_{0}$-N diagram with loading condition except early part of fatigue life. The ratio of half-value breadth B/B$_{0}$ with respect to number of cycle to failure N$_{f}$ has linear behavior on B/B$_{0}$-log N$_{f}$ diagram. Therefore, in this paper the estimation of fatigue life by average gradient method has much less estimated mean error than the estimation of fatigue life by log B/B$_{0}$-log N/N$_{f}$ relation.elation.ation.

• Journal of the Korean Ceramic Society
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• v.41 no.1
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• pp.9-12
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• 2004

The effect of x wt% CuO-y wt% $V_2O_5$ content on the microwave properties of $(Pb_{0.45}Ca_{0.55})[(Fe_{0.5}Nb_{0.5})_{0.9}Sn_{0.1}]O_3$ (PCFNS) ceramics was investigated. In order to decrease the sintering temperature and use as a Low Temperature co-firing Ceramics (LTCC), CuO-$V_2O_5$ are added in the PCFNS. The bulk density, dielectric constant (${\varepsilon}_r$) and quality factor(Q${\cdot}f_0$) increased with increase in CuO content within a limited value. The microwave properties were degraded with increases in $V_2O_5$ content. The temperature coefficient of the resonant frequency (${\tau}_f$) of PCFNS was shifted to positive value abruptly with increasing the $V_2O_5$ content, while the ${\tau}_f$ was slightly shifted to positive value with increasing the CuO content. The optimized microwave properties, ${\varepsilon}_r$ = 88, Q${\cdot}f_0$ = 6100 (GHz), and ${\tau}_f$ = 18 ppm/$^{\circ}C$, were obtained in $(Pb_{0.45}Ca_{0.55})[(Fe_{0.5}Nb_{0.5})_{0.9}Sn_{0.1}]O_3$ with 0.2wt% CuO 0.05 wt% $V_2O_5$ and sintered at $1000^{\circ}C$ for 3 h. The relationship between the microstructure and microwave dielectric properties of ceramics was studied by X-Ray Diffraction (XRD) and Scanning Electron Microscopy (SEM)

• Journal of the Korean Society of Fisheries and Ocean Technology
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• v.20 no.1
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• pp.1-5
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• 1984

The author carried out an experiment for the dynamical swimming force of crusian carp, Carassius carassius. The experimental water tank was made of 4mm thick transparent acryl board in the right hexahedral shape (400L$\times$240W$\times$800H mm). The water temperature in the tank ranged 20.6$^{\circ}C$ to 21.2$^{\circ}C$. The water level in the tank was maintained 70cm high from the bottom. The measurement of the swimming force was carried out by use of strain gauge. The results obtained can be summarized as follows: 1) The momentary maximum swimming force F sub(M) (g) and the sustainable maximum swimming force F sub(s) (g) can be expressed as a function of the body weight W(g). F sub(M) =1.45W, F sub(s) =0.29W where the momentary maximum swimming force means the highest value, and the sustainable maximum swimming force means the mean high value sustained for 4 to 5 seconds presented in the recording paper. 2) F sub(M) and F sub(s) can be expressed as a function of the body length L(cm). F sub(M) =0.11L super(2.63), F sub(s) =0.15L super(1.77) 3) The coefficient of hydraulic resistance for crusian carp was derived as 0.287.

• Journal of the Korea Academia-Industrial cooperation Society
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• v.14 no.6
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• pp.2958-2965
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• 2013

Purpose : To evaluate the degree of malignancy of incident thyroid lesion found in 18F-FDG PET/CT findings and the usefulness of the method suggested in this study, we applicate the Delay Scan Method that differentiate a false positive benign tumor, inflammation and malignancy, as well as make the criteria of SUV. Materials and Methods : A retrograde study was conducted of 25 patients(1 exception) who were admitted in E hospital to receive 18F-FDG PET/CT examination until Janaary and April of 2008. 18F-FDG PET/CT image photographing was taken in Biograph-Duo made by SIEMENS, after taking normal 18F-FDG PET/CT image(1hr) and then 1hr later we took the thyroid 1 bed-delayed image for the patients who showed abnormal thyroid 18F-FDG uptake and above 2.0 SUV for 2 minutes every 1 bed. For the patients who showed abnormal thyroid uptake and above 2.0 SUV, 1hr later, we took a 1 bed-delayed image and then made a comparative study between measured maxSUV of 1hr-abnormal uptake image and that of 2hr-delayed image. Results : In this 18F-FDG PET/CT study among the patients who showed incidental 18F-FDG thyroidal uptake the number of thyroid cancer was 5(20.8%), all of then showed benign findings. a comparison of results for 18F-FDG PET/CT. the benign patient measured maxSUV in the PET/CT. image(1hr) mean value 5.06maxSUV and delay image(2hr) mean value 5.23maxSUV differences of two value is 0.19maxSUV and the malignantIt patient measured maxSUV in the PET/CT. image(1hr) mean value 9.63maxSUV and delay image(2hr) mean value 10.65maxSUV differences of two value is 10.65maxSUV in Thyroid abnormal uptake patients. Conclusion : in the case of incidental 18F-FDG uptake in thyroid, max SUV of focal thyroid lesion is above 5.0 if 18F-FDG PET/CT examine the delayed images to add, You could see that reasonable diagnostic method useful. to differentiate whether lesions of malignant.

• Carbon letters
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• v.9 no.3
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• pp.188-194
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• 2008

Porous carbon materials synthesized from various plant derived precursors i.e. seeds of [Castor (Ricinus communis), Soap nut (Sapindus sp.), Cashew-nut (Semecarpus anacardium), Jack fruit (Artocarpus heterophyllus), Safflower (Carthamus tinctorius), Ambadi (Crotolaria juncea), Neem (Azadirachta indica), Bitter Almond (Prunus amygdalus), Sesamum (Sisamum indicum), Date-palm (Phoenix dactylifera),Canola (Brassica napus), Sunflower (Helianthus annulus)] and fibrous materials from [Corn stem- (Zea mays), Rice straw (Oryza sativa), Bamboo (Bombax bambusa) and Coconut fibers (Cocos nucifera)] were screened to make supercapacitor in 5M KOH solution. Carbon material obtained from Jack fruit seeds (92.0 F/g), Rice straw (83.0 F/g), Soap nut seeds (54.0 F/g), Castor seeds (44.34 F/g) and Bamboo (40.0 F/g) gave high capacitance value as compared to others. The magnitude of capacitance value was found to be inversely proportional to the scan rate of measurement. It is suggested that carbon material should possess large surface area and small pore size to get better value of capacitor. Moreover, the structure of carbon materials should be such that majority of pores are in the plane parallel to the plane of electrode and surface is fluffy like cotton ball.

• Journal of Sericultural and Entomological Science
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• v.10
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• pp.67-72
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• 1969

In order to analyse the correlation between the parents and their hybrids in the silkworm, which were reared in spring, the author has surveyed the various quantitative characters which are significant in genetics, and the hybrid vigor rate. The duration of larvae life is shorter in F1 Value an in the mid parents value, cocoon size biffer, pupa rate, cocoon crop from ten thousand silkworms just molted in the fourth instar, total cocoon weight and cocoon layer weight increases in comparison with the mid parents value. Although cocoon layer ratio only shows increasing by 0.3％ or so, it is too little to admit the effect. F1 value is nearly equal to parent value and there is no correlation between F1 hybrids value and their mid parents value.

• Journal of applied mathematics & informatics
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• v.27 no.3_4
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• pp.895-902
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• 2009

In this paper, the singular three-point boundary value problem $$\{{{u"(t)\;+\;f(t,\;u)\;=\;0,\;t\;{\in}\;(0,\;1),}\atop{u(0)\;=\;0,\;u(1)\;=\;{\alpha}u(\eta),}}\$$ is studied, where 0 < $\eta$ < 1, $\alpha$ > 0, f(t,u) may be singular at u = 0. By mixed monotone method, the existence and uniqueness are established for the above singular three-point boundary value problems. The theorems obtained are very general and complement previous know results.

• Kyungpook Mathematical Journal
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• v.55 no.1
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• pp.137-147
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• 2015

Let f be a transcendental meromorphic function of finite order in the plane such that $f^{(m)}$ has finitely many zeros for some positive integer $m{\geq}2$. Suppose that $f^{(k)}$ and f share a CM, where $k{\geq}1$ is a positive integer, $a{\neq}0$ is a finite complex value. Then f is an entire function such that $f^{(k)}-a=c(f-a)$, where $c{\neq}0$ is a nonzero constant. The results in this paper are concerning a conjecture of Bruck [5]. An example is provided to show that the results in this paper, in a sense, are the best possible.

• The Korean Journal of Malacology
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• v.28 no.3
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• pp.269-274
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• 2012

The genetic variation of Ark Shell, Scapharca broughtonii black was estimated using six polymorphic microsatellite (MS) loci in 443 individuals collected from five populations in Korea. The mean numbers of alleles per locus in five populations were 10-28. The mean number of alleles per locus in Jinhae Hatchery (JHH) population showed the least value as 15.5, but that in Gangjin (GJ) population showed the most value as 20.3. The mean expected heterozygosity in Saryangdo (SR) population showed the least value as 0.817, but that in Gangjin (GJ) population showed the most value as 0.831. In Jinhae hatchery(JHH) population, the mean expected heterozygosity was 0.822, there was no significant difference from those of wild population. The $F_{ST}$ values in Gangjin (GJ) population showed significant difference from those of the other populations, which revealed Gangjin (GJ) population is genetically different from the other populations. The $F_{ST}$ values among Jinhae Hatchery (JHH) population, Jinhae (JH) population and Saryangdo (SR) population showed lower values than the others, which implies there was a gene flow among these three populations. The $F_{ST}$ value and genetic distance between Jinhae (JH) population and Saryangdo (SR) population showed the least value as 0.0001 and 0.0386, indicating that these two populations were genetically the same.