• 한국전산유체공학회:학술대회논문집
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• 1999.05a
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• pp.192-198
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• 1999

The present study proposes modified temperature-dependent non-Newtonian viscosity model and investigates flow characters and heat transfer enhancement of the viscoelastic non-Newtonian fluid in a 2:1 rectangular duct. The proposed modified temperature dependent viscosity model has non-zero value near the high temperature and high shear rate region while on the existing viscosity models have zero value. Two versions of thermal boundary conditions involving difference combination of heated walls and adiabatic walls are analyzed in this study. The combined effect of temperature dependent viscosity, buoyancy, and secondary flow caused by second normal stress difference are ail considered. The Reiner-Rivlin model is adopted as a viscoelastic fluid model to simulate the secondary flow caused by second normal stress difference. Calculated Nusselt numbers by the modified temperature-dependent viscosity model gives under prediction than the existing temperature-dependent viscosity model in the regions of thermally developed with same secondary normal stress difference coefficients with experimental results in the regions of thermally developed. The heat transfer enhancement of the viscoelastic fluid in a 2:1 rectangular duct is highly dependent on the secondary flow caused by the magnitude of second normal stress difference.

• 한국신재생에너지학회:학술대회논문집
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• 2006.06a
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• pp.485-488
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• 2006

In order to investigate the possibility of waste mushroom logs as biomass resource chemical and physical characteristics of normal woods and waste mushroom logs such as crystallinity value, energy consumption, total sugar yield after hydrolysis chemical compounds and molecular weight distribution after acid hydrolysis, were examined. In the results, crystallinity of waste mushroom logs which were three year passed after the inoculation was decreased drastically from 49% to 33% during the cultivation. Lignin contents as chemical compounds of normal woods and waste mushroom logs were 21.07% and 18.78%, respectively. By the results of measurement of energy consumption, the size reduction of normal woods required a significantly higher energy than that of waste mushroom logs. In the hydrolysis, total sugar yield by enzyme and acid hydrolysis were high in waste mushroom logs(53% 57.5%) than in normal woods(42.9%, 47.17%). According to the molecular weight distribution using GPC, low molecular weight compounds were distributed in waste mushroom logs. Based on these results, waste mushroom logs have enough potential as material for developing alternative energy because of easily conversion to sugar by various hydrolysis methods and requirement of low energy consumption during size reduction.

• Journal of the Korean Society of Food Science and Nutrition
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• v.20 no.5
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• pp.426-432
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• 1991

To investigate the effect of the unsaturated plant oil on the normal liver and lipid metabalism rats were fed the daily dose of 1.57ml/kg body weight of perilla oil (Iodine value 190~207), corn oil (Iodine value 115~130) and olive oil (Iodine value 80~85) respectively for 28 days. The results were as follows. For the 14 days the test groups showed normal weight gain with 7.86~20.89% increase rate. In the period of the 3rd and the 4th week the increase rate of the perilla oil group was decreased significantly under 17.53~13.8% of control level, but the remainders(corn oil, olive oil) keep normal. The feeding of corn and olive oil for 28 days did show any harmful effect on normal GOT, GPT activity, ALK-P, serum cholesterol and serum triglyceride value of rat. The perilla oil feeding for 21~28 days slightly increased the GOT, GPT activity as 174.87, 93.46u but decreased the cholesterol and triglycerids value as 54.6~0.36mg/dl compared to control. In the pathological finding of test group liver some rats in 28 days feeding group showed reactive vesicula nuclei in corn oil group and mild fatty metamorphosis in olive oil group. But most subjects did not show any characterized sign of acute or subacute liver damage.

• Journal of Korean Society for Quality Management
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• v.42 no.2
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• pp.209-219
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• 2014

Purpose: The purpose of this study is to develop the statistical test for process capability index $C_p$ based on mixture normal process. Methods: This study uses Bootstrap method to calculate the approximate P-value for various simulation conditions under mixture normal process. Results: This study indicates that our proposed method is effective way to test for process capability index $C_p$ based on mixture normal process. Conclusion: This study finds out that statistical test for process capability index $C_p$ based on mixture normal process is useful for real application.

• Journal of Physiology & Pathology in Korean Medicine
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• v.17 no.1
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• pp.118-122
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• 2003

Oxidative stress and its consequent lipid peroxidation exert harmful effects, which have been currently involved in the generation of carbon tetrachloride (CCl₄)-induced fibrosis(cirrhosis). In this study, it was investigated whether dried extract of 田螺(Concha Cipangopaludinae; CC) has liver functional improvement, antioxidative and antifibrotic effect in rats those were induced liver fibrosis by CCl₄ administration. The female Sprague-Dawley rats were divided into 3 groups(Normal, AC, AC-CC) and were observed in 6 weeks. Except for normal group, liver fibrosis(cirrhosis) in rats were developed by CCl₄ administration(0.8 ㎖/rat/week). And the rats were treated with prepared CC(p. o. 2 ㎖/day/rat). At the time of sacrifice, the liver, kidney and spleen were weighed and the ratio of organ weight/body weight was calculated. The MDA, hyp and biochemical parameters(AST, ALT, ALP, t-bili) were measured in sera and liver tissue of rats. The strong yellow color of urine was observed in all CCl₄-treated group compared with normal group, but jaundice didn't appear in CCl₄-treated group. The mortality of CCl₄-treated group is very low(<13%) during 6 weeks of observation time. The ratio of liver/body as well as the weight of liver in CCl₄-treated rats significantly increased compared with that in normal group(p<0.001). The level of clinical parameters in sera of all liver fibrosis(cirrhosis) developed rats were significantly higher than that of normal group(p<0.001-0.05). Especially the value of BUN, ALP, t-bilirubin in AC-CC group showed 20.9%, 19.6%, 47.9% lower than that in AC group. The content of hyp in CCl₄-treated rats was significantly higher than normal group(p<0.001～<0.05), and showed 12.2% lower value in the AC-CC group than AC group(p<0.05). The production of lipid peroxidation(MDA) in sera and liver tissue significantly increased under the fibrotic(cirrhotic) condition(p<0.001～<0.05). Especially the MDA value of AC-CC group in sera significantly 46.5% decreased compared with that of AC group(p<0.05), and the MDA value of AC-CC in liver tissue showed 21.4% lower than that of AC group. Concha Cipangopaludinae can be improved hepatic function, and maybe have effect of liver protection, antioxidation and antifibrosis.

• The Korean Journal of Nuclear Medicine
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• v.19 no.1
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• pp.127-136
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• 1985

To evaluate change of serum $beta_2-microglobulin$ concentration$(s\beta_2-MG)$ and the usefulness of $s\beta_2-MG$ and $s\beta_2-MG/serum$ creatinine concentration(sCr) ratio in various renal diseases, $s\beta_2-MG$ and sCr were measured in 25 normal controls and 90 patients of various renal diseases(16 cases of glomerulonephritis, 12 cases of acute renal failure, 8 cases of chronic renal failure, 24 cases of nephrotic syndrome, 15 cases of tubulointerstitial diseases and 15 cases of lupus nephritis) using $Phadebas^\circledR$ $Beta_2-Micro$ Test kits. The results were as follows; 1) In normal control, the mean value of $s\beta_2-MG$ was $1.65{\pm}0.41mg/l$ and the mean value of $s\beta_2-MG/sCr$ ratio was $0.14{\pm}0.05$. 2) In various renal diseases, the mean value of $s\beta_2-MG$ was $6.74{\pm}5.47mg/l$. The mean value of $s\beta_2-MG/sCr$ ratio was $0.24{\pm}0.11$ and significantly elevated than that of normal control. (p<0.05) 3) The correlation between $s\beta_2-MG$ and sCr in glomerular and tubulointerstitial disease was log $s\beta_2-MG-0.90$ log sCr-0.48 and its correlation coefficient was 0.78(p<0.05). 4) In glomerular disease, the correlation between $s\beta_2-MG$ and sCr was log $s\beta_2-MG-0.89$ log sCr-0.46(r - 0.76) and in tubulointerstitial disease, it was log, $s\beta2-MG-0.95$ log sCr-0.59 (r-0.87). There was no significant difference between the two groups(p<0.05). 5) Among 32 cases of glomerular and tubulointerstitial disease patients, whose sCr was within normal range, 17 cases showed elevated $s\beta_2-MG$. The mean values of $s\beta_2-MG/sCr$ ratio in these patients was $0.30{\pm}0.14$ and significantly elevated than that of normal control(p<0.05). 6) In 15 cases of lupus nephritis, 12 cases showed elevated $s\beta_2-MG$ with normal sCr and 12 cases showed elevated $s\beta_2-MG/sCr$ ratio. With above results, it was found that the $s\beta_2MG$ can be used as an index of glomerular filtration rate as in the case of sCr and that $s\beta_2-MG/sCr$ ratio can be used as a tool in early detection of slightly decreased glomerular filtration rate and in detection of the renal disease of increased $\beta_2-MG$ production.

• Journal of applied mathematics & informatics
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• v.8 no.1
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• pp.137-149
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• 2001

In this paper we consider some nonlinear parabolic partial differential equations with distributed deviating arguments and establish sufficient conditions for the oscillation of some boundary value problems.

• Journal of the Korean Mathematical Society
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• v.47 no.6
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• pp.1107-1122
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• 2010

In this paper, we shall use analytic methods to study the hybrid mean value involving the mixed two-term exponential sums C(m, n, r, $\chi$; q), and give several sharp asymptotic formulae.

• Communications for Statistical Applications and Methods
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• v.7 no.3
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• pp.913-926
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• 2000

An electronic statistics text on the web is implemented. The introduced text provide interactive instructions on the statistical estimation and inference. As a by-product, we also provide a calculation of quantiles and p-value of t-distribution and standard normal distribution. This program was written in JAVA programming language.

• Bulletin of the Korean Mathematical Society
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• v.61 no.3
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• pp.597-610
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• 2024

Using the Nevanlinna value distribution theory of algebroid functions, this paper investigates the growth of two types of complex algebraic differential equation with algebroid solutions and obtains two results, which extend the growth of complex algebraic differential equation with meromorphic solutions obtained by Gao [4].