• Journal of the Korea Society of Computer and Information
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• v.26 no.8
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• pp.157-164
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• 2021

Regression analysis is a well-known statistical technique useful to explain the relationship between response variable and predictor variables. In particular, Researchers are interested in comparing the regression coefficients(intercepts and slopes) of the models in two independent populations. The Chow test, proposed by Gregory Chow, is one of the most commonly used methods for comparing regression models and for testing the presence of a structural break in linear models. In this study, we propose the use of permutation method and compare it with Chow test analysis for testing the equality of two independent linear regression models. Then simulation study is conducted to examine the powers of permutation test and Chow test.

• Journal of the Korean Mathematical Society
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• v.45 no.2
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• pp.467-477
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• 2008

In this paper, we provide a criterion for Chow stability in terms of log canonical threshold of the Chow form in the Grassmannian.

• Bulletin of the Korean Mathematical Society
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• v.50 no.3
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• pp.1029-1040
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• 2013

In this paper, we give sufficient conditions on a canonical genus 4 curve for it to be Chow (semi)stable.

• Bulletin of the Korean Mathematical Society
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• v.54 no.5
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• pp.1827-1849
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• 2017

We prove that if a smooth projective algebraic variety of dimension less or equal to three has a unit type integral K-motive, then its integral Chow motive is of Lefschetz type. As a consequence, the integral Chow motive is of Lefschetz type for a smooth projective variety of dimension less or equal to three that admits a full exceptional collection.

• Korean Journal of Exercise Nutrition
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• v.13 no.2
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• pp.93-100
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• 2009

This study was conducted to investigate the effect of exercise training on blood and metabolic variances and genes expressions in hyperlipidemic rats. Three weeks-old male rats were randomly assigned into chow (n=7), high-fat diet (HF, n=7) and HF+exercise (HF+EX, n=7) groups. Exercise training consisted of the treadmill running 5 times per week during 8 weeks (0% grade, 30 min/time for first 4 weeks and 0% grade, 60 min/time the other 4weeks). The levels of triglyceride and total -cholesterol were increased in HF diet compared with chow group, and recovered to level of chow group by exercise training. Plasma glucose and insulin concentrations increased by 40 and 50%, respectively in HF diet compared with chow diet group, and these increases returned to the level of chow group by exercise training (p<.05). Body weight and abdominal fat mass were increased by high-fat diet compared with chow diet, and recovered to level of chow group by exercise training. Long-chain fatty acid oxidation rate and AMPK protein expression was not changed by HF diet, but increased by exercise training compared with high-fat diet (p<.05). UCP3 protein expression was not changed by either high-fat diet or exercise training compared with chow group. There was high correlation between plasma triglyceride and total cholesterol concentrations(p<.01). Plasma triglyceride or total cholesterol level showed correlation with following factors; plasma insulin and glucose levels, body weight, abdominal fat weight, UCP3 protein expression and long-chain fatty acid oxidation rate. These results showed that exercise training on the treadmill recovered hyperlipidemia, hyperglycemia and hyperinsulinemia induced by high-fat diet for 8 weeks. These exercise effects may be related with decreased body weight and abdominal fat mass, and increased long-chain fatty acid oxidation rate.

• Korean Journal of Veterinary Service
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• v.40 no.3
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• pp.215-217
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• 2017

A 3-year-old chow chow dog with abdominal distention was referred to the Veterinary Teaching Hospital of Chungnam National University. The dog was diagnosed as Cor triatriatum dexter based on echocardiographic results, which demonstrated an abnormal membrane partitioning the right atrium. Echocardiography also revealed turbulent intra-atrial blood flow between the two chambers of the atrium. The dog was treated with balloon dilatation to enlarge the perforation in the abnormal membrane and to improve blood flow. As a result, although the membrane remained, increased perforation reduced the turbulent intra-atrial blood flow. Clinically the patient improved and eventually was discharged. This case is the first domestic Korean clinical veterinary report on the use of balloon valvuloplasty to treat Cor triatriatum dexter in a dog.

• Journal of Nutrition and Health
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• v.40 no.3
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• pp.221-228
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• 2007

We determined the effects of dietary manipulations on messenger RNA of peroxisome proliferators activated receptor isoforms (i.e., PPAR ${\alpha},\;{\beta}/{\delta},\;{\gamma}$) in red vastus lateralis muscle of rats. Total 16 male Sprague-Dawley rats were used, and animals were divided into one of two dietary conditions: either chow diet group (CHOW; n=8) in which animals were 134 with standard rodent chow (61.8% carbohydrate, 15.7% fat, 22.5% protein) or high fat diet group (FAT n=8) in which animals were fed 24.3% carbohydrate, 52.8% fat, 22.9% protein. At the end of the 8 weeks of experimental period, red vastus lateralis muscle was dissected out from all animals, and PPAR ${\alpha},\;{\beta}/{\delta},\;{\gamma}$ mRNA expression was determined. There was no significant difference in body mass (BM) between CHOW and FAT. As expected, blood glucose and free fatty acid (FFA) concentration was higher in FAT than CHOW (p<0.05), and lactate concentration was significantly lower in FAT compared to CHOW (p<0.05). Insulin concentration tended to higher in FAT than CHOW ($67.2{\pm}21.9\;vs.\;27.0{\pm}5.2$ pmol/L), but it did not reach to the statistical significance. Gene expression of PPAR ${\alpha}$ was not significantly different between CHOW and FAT. It was not also significantly different in PPAR ${\beta}/{\delta}$. Interestingly, expression of mRNA in PPAR ${\gamma}$ however, was markedly depressed in FAT compared to CHOW (approximately 3 fold higher in CHOW; p<0.05). Results obtained from present study implies that PPAR ${\gamma}$ (as compensatory function of PPAR ${\alpha}$ is expressed) possibly exerts another major tuning roles in fatty acid transport, utilization, as well as biosynthesis in skeletal muscle cells. The situations and conditions that can be postulated for this implication need to be further examined.

• Journal of computational fluids engineering
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• v.7 no.1
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• pp.10-19
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• 2002

The non-staggered(collocated) grid approach in which all the solution variables are located at the centers of control volumes is very popular for incompressible flow analyses because of its numerical efficiency on the curvilinear or unstructured grids. Rhie and Chow's paper is the first in using non-staggered grid method for SIMPLE algorithm, where pressure weighted interpolation was used to prevent decoupling of pressure and velocity. But it has been known that this non-staggered grid method has stability problems when pressure fields are nonlinear like in natural convection flows. Also Rhie-Chow scheme generates large numerical diffusion near curved walls. The cause of these unwanted problems is too large pressure damping term compared to the magnitude of face velocity. In this study the magnitude of pressure damping term of Rhie-Chow's method is limited to 1∼10% of face velocity to prevent physically unreasonable solutions. The wall pressure extrapolation which is necessary for cell-centered FVM is another source of numerical errors. Some methods are applied in a unstructured FV solver and analyzed in view of numerical accuracy. Here, two natural convection problems are solved to check the effect of the Rhie-Chow's method on numerical stability. And numerical diffusion from Rhie-Chow's method is studied by solving the inviscid flow around a circular cylinder.

• Korean Journal of Exercise Nutrition
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• v.25 no.2
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• pp.8-14
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• 2021

[Purpose] The purpose of this study was to investigate the effects of a high-fat high-sucrose (HFHS) diet on previously reported adaptations of cardiac morphological and contractile properties to resistance training. [Methods] Twelve-week-old rats participated in 12-weeks of resistance exercise training and consumed an HFHS diet. Echocardiography and skinned cardiac muscle fiber bundle testing were performed to determine the structural and mechanical adaptations. [Results] Compared to chow-fed sedentary animals, both HFHS- and chow-fed resistance-trained animals had thicker left ventricular walls. Isolated trabecular fiber bundles from chow-fed resistance-trained animals had greater force output, shortening velocities, and calcium sensitivities than those of chow-fed sedentary controls. However, trabeculae from the HFHS resistance-trained animals had greater force output but no change in unloaded shortening velocity or calcium sensitivity than those of the chow-fed sedentary group animals. [Conclusion] Resistance exercise training led to positive structural and mechanical adaptations of the heart, which were partly offset by the HFHS diet.

• Communications of the Korean Mathematical Society
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• v.11 no.3
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• pp.569-573
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• 1996

We study some special cases of Chow groups of a ramified complete regular local ring R of dimension n. We prove that (a) for codimension 3 Gorenstein ideal I, [I] = 0 in $A_{n-3}(R)$ and (b) for a particular class of almost complete intersection prime ideals P of height i, [P] = 0 in $A_{n-i}(R)$.