• Journal of the Chungcheong Mathematical Society
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• v.27 no.3
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• pp.393-401
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• 2014

In this work, we discuss the existence of mild solutions in the ${\alpha}$-norm for some partial functional integrodifferential equations with infinite delay. We assume that the linear part generates an analytic semigroup on a Banach space X and the nonlinear part is a Lipschitz continuous function with respect to the fractional power norm of the linear part.

• Journal of Applied and Pure Mathematics
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• v.5 no.3_4
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• pp.129-164
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• 2023

The aim of this work is to present some interesting results on weighted ergodic functions and prove the existence and uniqueness of Stepanov-like pseudo almost automorphic solutions using the spectral decomposition of the phase space developed by Adimy and co-authors. We also give the next challenge of this work.

• Journal of Yeungnam Medical Science
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• v.16 no.2
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• pp.309-317
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• 1999

Background: Left ventricular diastolic filling is an important determinant for maintenance of cardiac output during hemodialysis. Few investigators have studied the influence of hemodialysis on diastolic function. To evaluate the change of left ventricular systolic and diastolic function. we performed M-mode and Doppler echocardiographic studies before and after hemodialysis. Methods: The study population consisted of 30 patients(15 patients were male, mean age $45{\pm}10$ years) with CRF on maintenance hemodialysis. They have normal left ventricular systolic function(Fractional shortening>30%) and no evidence of valvular heart disease or regional wall motion abnormalities. The ejection fraction (EF) was measured using M-mode echocardiography and Doppler indices such as peak E velocity, peak A velocity, isovolumetric relaxation time(IVRT), deceleration time(DT). and left ventricular ejection time(LVET) obtained from Doppler echocardiography. The index of myocardial performance (IMP) was calculated from each of the Doppler velocity indices. Results: The weight reduction after hemodialysis was $2.1{\pm}1.0kg$(p<0.0001), After hemodialysis, there was some decrease in blood pressure(p<0.05), but no significant change in heart rate, EF and fractional shortening, mean VCF, peak A velocity, and DT. And significant reduction in peak E velocity, E/A ratio(p<0.0001. p<0.001), and significant increase in IVRT and IMP(p<0.05, p<0.0001) were noted. Conclusion: In conclusion, preload reduction is the main mechanism that accounts for changes in Doppler diastolic indices after hemodialysis. And an increased IMP suggests that diastolic function may be aggravated after hemodialysis, and that implies impaired left ventricular filling and disturbed left ventricular compliance.

• Toxicological Research
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• v.26 no.4
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• pp.329-337
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• 2010

Inhaled inorganic dusts, such as coal, can cause inflammation and fibrosis in the lungs, known as pneumoconiosis. Diagnosis of pneumoconiosis depends on morphological changes by radiological findings and functional change by pulmonary function test (PFT). Unfortunately, current diagnostic findings are limited only to lung fibrosis, which is usually irreversibly progressive. Therefore, it is important that research on potential and prospective biomarkers for pneumoconiosis should be conducted prior to initiation of irreversible radiological or functional changes in the lungs. Analytical techniques using exhaled breath condensate (EBC) or exhaled gas are non-invasive methods for detection of various respiratory diseases. The objective of this study is to investigate the relationship between inflammatory biomarkers, such as EBC pH or fractional exhaled nitric oxide ($FE_{NO}$), and pneumoconiosis among 120 retired coal miners (41 controls and 79 pneumoconiosis patients). Levels of EBC pH and FENO did not show a statistically significant difference between the pneumoconiosis patient group and pneumoconiosis patients with small opacity classified by International Labor Organization (ILO) classification. The mean concentration of $FE_{NO}$ in the low percentage $FEV_1$ (< 80%) was lower than that in the high percentage (80% $\leq$) (p = 0.023). The mean concentration of $FE_{NO}$ in current smokers was lower than that in non smokers (never or past smokers) (p = 0.027). Although there was no statistical significance, the levels of $FE_{NO}$ in smokers tended to decrease, compared with non smokers, regardless of pneumoconiosis. In conclusion, there was no significant relationship between the level of EBC pH or $FE_{NO}$ and radiological findings or PFT. The effects between exhaled biomarkers and pneumoconiosis progression, such as decreasing PFT and exacerbation of radiological findings, should be monitored.

• The Bulletin of The Korean Astronomical Society
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• v.37 no.2
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• pp.108.2-108.2
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• 2012

Recent results from microlensing surveys show that a free-floating planet or a wide-separation planet is more numerous than a main-sequence star in the Galaxy. Moreover, the detection efficiency of the planets will be improved in next-generation experiments with a high survey monitoring frequency. However, microlensing events produced by both planets appear similar light curves with a short duration timescale, thus it is difficult to distinguish them. In this paper, we investigated the detectable separation range of a wide-separation planet as the planet bound to its host star. We construct the fractional deviation maps using the magnifications of the planetary lensing and the single-lensing by planet itself for various parameters such as a mass ratio, separation, and source radius. As a result, we found that the pattern of the fractional deviation is related to the ratio of source radius to caustic size, and the ratio satisfying the detection criterion (i.e., ${\geq}5%$ in the fractional deviation) varies with a separation. Hence, we derived a fitting formula as the function of a mass ratio and a source radius to reflect the variation in the calculations of the detectable separation range of a wide-separation planet as the planet bound to its host star. In addition, we estimated the condition that a wide-separation planet can be detected as a single-lensing event under the finite source effect. We found that such a case is possible provided that the source radius is smaller than ~2.5 times of Einstein ring radius of a planet, regardless of a separation or a mass ratio.

• Journal of Korean Society of Coastal and Ocean Engineers
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• v.17 no.1
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• pp.21-31
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• 2005

In this study, derivation is made of a one-grid source function for the extended Boussinesq equations of Nwogu (1993) in order to generate nonlinear waves internally. The energy velocity approach used in the line source method is verified analytically by the fractional step splitting method. The source function method is verified by generating accurately nonlinear waves as well as linear waves for horizontally one-dimensional cases. It is found that numerical solutions by the source function method are the same as those by the line source method.

• Transactions of the Korean Society of Mechanical Engineers
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• v.15 no.2
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• pp.497-506
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• 1991

In this paper, a new construction for training simulator of R/C helicopter based on two types of servo controller is proposed. Two modified algorithms (algorithm I and II) for servo controller design are presented. Algorithm I is developed by adopting Davison's method in the case that the expressions for the homogeneous differential equations of reference input and disturbance are different types, and algorithm II is done by considering error weighting function for the servo controller of algorithm I . The linear fractional transformation method is incorporated in both design methods in order to assign the closed loop poles of the servo system in a specified region. The helicopter simulator is composed by the gimbals with two freedom of rolling and pitching. The reliability and validity for the design methods of the proposed servo controller are investigated through the practical experiment for the simulator by using 16bits micro-computer with A/D and D/A converters. It can be observered from the experimental results that the proposed servo controller is applicable to practical plants since the simulator is robust for the arbitrary disturbance and it follows to the given reference input without significant steady state error.

• Journal of Microbiology and Biotechnology
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• v.12 no.3
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• pp.522-525
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• 2002

A very rapid and efficient separation technique for cellular rhizobial cyclosophoraoses was developed based on fractional precipitation and partition chromatography. Cyclosophoraoses are known to function in the osmotic regulation and root nodule formation of legumes during the nitrogen fixation process. Cyclosophoraoses are produced as unbranched cyclic (1longrightarrow12)-${\beta}$-D-glucans in Agrobacterium or Rhizobium species. Recent research has shown that cyclosophoraoses can form inclusion complexation with various unstable or insoluble guest chemicals, thereby implying great potential for industrial application. Typical separation of pure cellular cyclosophoraoses has been so far carried out by several time-consuming steps, including size exclusion, anion exchange, and desalting liquid chromatographies, with a relatively poor recovery. However, the proposed method demonstrated that the successive application of fractional ethanol precipitation and one step of silica gel-based flash column chromatography was enough to simultaneously purify neutral or anionic forms of cyclosophoraoses. This novel technique is very rapid and provides a high recovery.

• Proceedings of the KIEE Conference
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• 1999.11d
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• pp.879-881
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• 1999

Radical and ion densities in a CF4 plasma have been calculated as a function of input power density. 9as pressure and feed gas flow rate using simple 0 dimensional global model. Fluorine atom is found to be the most abundant neutral particle. Highly fragmented species such as CF and CF+ become dominant neutral and ionic radical at the high power condition. As the pressure increases. ion density increases but ionization rate decreases due to the decrease in electron temperature. The fractional dissociation of CF4 feed gas decreases with pressure after increasing at the low pressure range. Electron density and temperature are almost independent of flow rate within calculation conditions studied. The fractional dissociation of CF4 monotonically decreases with flow rate. which results in increase in CF3 and decrease in CF density. The calculation results show that the SiO2 etch selectivity improvement correlates to the increase in the relative density of fluorocarbon ion and neutral radicals which has high C/F ratio.

• The Bulletin of The Korean Astronomical Society
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• v.41 no.1
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• pp.68.3-68.3
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• 2016

We analyze the dependence of environment of warped galaxies by using the local background density, Tidal Index and projected distance as measures of the environment. we use galaxies with redshift less than z=0.025 from the Sloan Digital Sky Survey (SDSS) DR7. We selected 345 edge-on galaxies using color images provided by the SDSS DR7 and checked it using isophotal maps. This sample contains 136 warped galaxies, 209 non-warped galaxies. Among warped galaxies, there are 18 strongly warped galaxies which have warp angles larger than 7.5o. We calculated the fractional distributions of galaxies as a function of environmental parameters. All of these parameters show little difference between warped galaxies and non-warped galaxies if we include weakly warped galaxies. However, there is a clear difference in the fractional distributions between the strongly warped galaxies and non-warped galaxies. The fraction of warped galaxies increases with decreasing distance to the nearest neighbor galaxy but It increases with increasing background density and Tidal Index. However, the relationships between warp angles and the three environmental parameters are not strong. The effect of Tidal Index is well distinguished in small, bright galaxies whereas the effects of the background density and the distance to the nearest neighbor galaxy are more pronounced in large, bright galaxies.