• Journal of Medicine and Life Science
• /
• 제20권3호
• /
• pp.107-114
• /
• 2023

Epidemiological control of coronavirus disease 2019 (COVID-19) is needed to estimate the infection period of confirmed cases and identify potential cases. The present study, targeting confirmed cases for which the time of COVID-19 symptom onset was disclosed, aimed to investigate the relationship between intervals (day) from symptom onset to testing the cycle threshold (CT) values of real-time reverse transcription-polymerase chain reaction. Of the COVID-19 confirmed cases, those for which the date of suspected symptom onset in the epidemiological investigation was specifically disclosed were included in this study. Interval was defined as the number of days from symptom onset (as disclosed by the patient) to specimen collection for testing. A locally weighted regression smoothing (LOWESS) curve was applied, with intervals as explanatory variables and CT values (CTR for RdRp gene and CTE for E gene) as outcome variables. After finding its non-linear relationship, a polynomial regression model was applied to estimate the 95% confidence interval values of CTR and CTE by interval. The application of LOWESS in 331 patients identified a U-shaped curve relationship between the CTR and CTE values according to the number of interval days, and both CTR and CTE satisfied the quadratic model for interval days. Active application of these results to epidemiological investigations would minimize the chance of failing to identify individuals who are in contact with COVID-19 confirmed cases, thereby reducing the potential transmission of the virus to local communities.

• 한국기계가공학회지
• /
• 제17권3호
• /
• pp.45-50
• /
• 2018

From the flow analysis of the silencer for 8 kW diesel generators, the following results were obtained. For silencer-1, it was confirmed that the holes formed at the inlet-side portion connect into the exhaust pipe in the chamber. The exhaust pipe installed inside silencer-1 was integrally connected through the holes in the chamber. As a result, it was confirmed that the pressure inside the chamber was kept stable. It was confirmed that the pressure loss generated inside an absorptive type silencer such as silencer-2 was small. The differential pressure of the inlet-outlet of silencer-1 and silencer-2 was confirmed to be 494 Pa at 15 m/s, 859 Pa at 20 m/s, 1326 Pa at 25 m/s, and 1911 Pa at 30 m/s.

• 한국정밀공학회지
• /
• 제27권7호
• /
• pp.94-100
• /
• 2010

This paper describes the design and evaluation procedure of an ultra-precision rotary table for freeform generating machined tools. Design of the thrust and journal hydrostatic bearings and experimental evaluation of the table were performed. To get the compact size and less lost motion direct drive servomotor with ultra precision encoder. From the considered design, following performance were confirmed by experiment. The total stiffness of the prototype rotary table was 483.6 $N/{\mu}m$ and 97.6 $N/{\mu}m$ for axial and radial direction, respectively. Rotational accuracy of the table was investigated by capacitive sensor and reversal measurement technique, and 0.10 ${\mu}m$ radial direction and 0.05 ${\mu}m$ axial direction of the rotational accuracy were confirmed. The micro resolution of the table was also investigated with displacement of capacitive sensor, and $0.5/10000^{\circ}$ of micro resolution was confirmed. Index accuracy of the table was evaluated by the autocollimator and polygon mirror, and the $\pm0.39$ arcsec accuracy and $\pm0.16$ arcsec repeatability of the table were confirmed. Those are under the general requirements of ultra precision rotary tables for freeform generating machined tools.

• 한국식품영양학회지
• /
• 제34권6호
• /
• pp.561-567
• /
• 2021

Curcumin is not soluble in water. Therefore, curcumin emulsion that can dissolve well in water were prepared using multi-emulsification technology, and the antioxidant activities and physical properties of emulsion were measured. Although curcumin was not dissolved in water, it was confirmed to be well dispersed in water when prepared in an aqueous dispersion curcumin emulsion. After dissolving curcumin using water and ethanol as solvents, respectively, the DPPH and ABTS radical scavenging abilities of the filtrate and the curcumin emulsion were measured. Because it was not dissolved in water, activities were not shown. However, when curcumin was dissolved in ethanol, the activities increased as the concentration of curcumin increased. On the other hand, when the curcumin emulsion was dissolved in water, it was found to have abilities. The curcumin emulsion was nano-homogenized and the size and distribution of the emulsified spheres were measured. It was confirmed to be nano-sized as it appeared as 9.083 nm/100%. In the results of the DPPH radical and ABTS radical scavenging abilities of curcumin nano-emulsion, it was confirmed that there was no change in the antioxidant abilities. In conclusion, water-dispersible curcumin prepared using multi-emulsification technology, and it was confirmed to exhibit antioxidant activity and emulsion stability.

• 한국생산제조학회지
• /
• 제23권6호
• /
• pp.590-595
• /
• 2014

We have investigated anamorphic prism lenses with distortions of 0.3-0.5%. We designed the plastic triangular lens and confirmed the minimum resolution using MTF graphs. Also we confirmed that the SVGA optical system can realize a resolution of $864{\times}648$ 56 megapixels. A distortion of about 0.5% aberration appears in the maximum field, and a finite beam aberration of about $15{\mu}m$ is confirmed. We made a mold based on the design data and completed the prism lens through exodus molding. We confirmed the shape error (< $30{\mu}m$) and surface roughness (> 40 nm) of the three sides. We made the video-information-display prototype glasses using prism lens by measuring the performance, we determined the distortion aberration (0.3%) and SVGA resolution. Our approach will enable fabrication of a portable large-screen display device for glasses and sunglasses for the domestic market and, after 2015, for the world market.

• 한국자원식물학회지
• /
• 제36권3호
• /
• pp.198-206
• /
• 2023

The effectiveness of the extracts of Alnus japonica and Portulaca oleracea, which are effective in improving alcohol-induced liver damage, was confirmed using acute and chronic alcoholic liver injury animal models. In the acute alcoholic liver injury model, dieting Alnus japonica and Portulaca oleracea complex (ALPOC) at a dose of 50 mg/kg showed no significant change in liver or body weight, while measured plasma ALT activity to be deficient (28.12 U/ml) compared to the alcohol intake group (42.5 U/ml), and confirmed that restored it to an average level. It showed an improvement of 34.9% compared to the alcohol intake group. AST activity confirmed that it showed a very effective liver protection activity by showing a gain of 12.6%. The chronic alcoholic liver damage animal model demonstrated that ALT showed an improvement effect of 25%, and AST showed an effect similar to that of the positive control group, Hovenia extract. In addition, through H&E staining analysis, observed that the ALPOC improved the necrosis and bleeding of the liver. And the ALPOC group showed intense antioxidant activity of 127% or more compared to the alcohol intake group, and this was confirmed to have a very high activity, which is more than 20% higher than that of the hovenia fruit extract.

• 전기학회논문지
• /
• 제63권9호
• /
• pp.1259-1265
• /
• 2014

In this paper, the real-time attitude determination based Matlab using low-cost receivers was designed and evaluated. The GNSS attitude determination system was implemented to operation in real-time by TimerCallback in MATLAB. The TTM(Transmission Time Misalignment) of U-blox receiver was confirmed through zero baseline tests and this problem was revised. The computed attitude by the high-cost NovAtel receiver was compared to the computed attitude by the low-cost U-blox receiver. As a result of this, the performance of attitude determination systems by low-cost receiver was confirmed. To determine baseline, LAMBDA and BC-LAMBDA for integer ambiguities search methods were used. To confirm suitable integer ambiguity search method in real-time attitude determination algorithm, determined baselines by two methods were compared, and it was confirmed that BC-LAMBDA is more suitable. As a result of this, the operation of real-time attitude determination system was confirmed using 3 low-cost receivers.

• 한국간호교육학회지
• /
• 제25권3호
• /
• pp.321-330
• /
• 2019

Purpose: The purpose of this study was to analyze the validity and reliability of the personality measurement tool for nursing college students. Methods: Questionnaires were issued to 300 nursing students, with 275 eventually collected. The items were confirmed by validity experts. Construct validity was tested using exploratory factor analysis and confirmatory factor analysis. Reliability analysis was tested using Cronbach's ${\alpha}$. Criterion validity was tested by analyzing correlation with the college adjustment scale. Results: Eight factors were confirmed by exploratory factor analysis. Confirmatory factor analysis was used to confirm the model fit (Root-mean-square residual .03; Root-mean-square error of approximation .06; Comparative fit index .92); and convergent validity and discriminant validity were confirmed. In addition, the criterion validity was confirmed through correlation (r=.64, p<.001) with the college adjustment scale. The reliability of this tool was Cronbach's ${\alpha}$ .94. Conclusion: This tool can be used to measure personality in nursing education and can be used to develop and evaluate personality programs.

• 한국식품영양학회지
• /
• 제36권4호
• /
• pp.296-308
• /
• 2023

This study investigated the anti-obesity effects of Coriandrum sativum L. ethanol extracts in a high fat diet-induced obesity model (DIO). We confirmed the anti-obesity effects by analysing the expression of the related proteins, weight gain, dietary intake, dietary efficiency, blood biochemistry, histological analysis and western blot analysis. After oral administration of Coriandrum sativumL. ethanol extracts at concentrations of 250 and 500 mg/kg, a significant improvement in dietary efficiency, reduction in weight gain, triglycerides, total cholesterol and LDL-cholesterol in blood lipid was observed for 8 weeks. In addition, improvement in blood glucose and metabolism confirmed through glucose tolerance test was observed. Further, the concentration of alanine transaminase (ALT) in blood was significantly decreased, which improved the fatty liver caused by high-fat diet intake as confirmed by liver tissue analysis. This phenomenon was confirmed to decrease the expression of fat accumulation-related PPARγ and FAS protein in the liver tissue. Especially, it is believed that FAS, a liposynthetic enzyme, has a stronger inhibitory effect than PPARγ. Therefore, Coriandrum sativum L. ethanol extract is thought to improve obesity by reducing blood lipids levels, improving glucose metabolism and inhibiting synthesis of the fat that accumulates in the liver in high-fat diet-induced obesity animal models.

• 상하수도학회지
• /
• 제32권5호
• /
• pp.453-460
• /
• 2018

The impact of sodium hydroxide, which is one of chemicals of clean in place (CIP) for removing membrane fouling, on the PVDF membrane is reviewed with respect to physical/chemical structural change, the permeability affected therefrom. Based on the cleaning concentration applied in membrane water treatment facilities, 10% of accumulated defluorination was confirmed up to 166g.hr/L which reflects the exposure time. However, membrane resistance was confirmed to be reduced by about 10%. Through FT-IR and EDS analysis, reduction of F and change of are confirmed as factors that affect the permeability of membrane. Membrane resistance, which affects permeability, is affected by loss of additives for hydrophilicity, rather than defluorination of PVDF material. Therefore, in order to check membrane degradation degree, an accelerated test by NaOH was carried out, loss of additives was confirmed, and then PVDF inherent characteristic was observed.