• Proceedings of the Korean Institute of Building Construction Conference
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• 2006.11a
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• pp.103-106
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• 2006

This study investigates spalling properties of 60MPa class, high performance concrete, made with the various influential parameters, such as, blaine of cement, mineral admixture and polypropylene(PP) fiber contents. Totally 21 parameters of ${\phi}100{\times}200mm$ in size was fabricated; three specimens for variance in blaine of cement, 4 specimens for combination of mineral admixture type, along with 0.05, 0.1, 0.15% of fiber adding ratio. After that, one hour unloading fire test was conducted, and then spalling appearance and spalling degree of specimens was examined. Test showed that a specimen made with high blaine of cement(H) improved early strength but exhibited similar value to a specimen made with low blaine(L) at the age of 28 days, thus indicating comparable spalling appearance. In conclusion, spalling easily occur in higher strength and smaller particle shape of cement and mineral admixture.

• Computers and Concrete
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• v.32 no.2
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• pp.185-206
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• 2023

This article aimed to explore the optimization of mineral admixtures and retarding admixture for high-performance concrete. In essence, fresh concrete can be regarded as a mixture in which both coarse and fine aggregates are suspended in a cement-based matrix paste. Based on this view, the test procedure was divided into three progressive stages of binder paste, mortar, and concrete to explore their rheological behavior and mechanical properties respectively. At each stage, there were four experimental control factors, and each factor had three levels. In order to reduce the workload of the experiment, the Taguchi method with an L9(3⁴) orthogonal array and four controllable three-level factors was adopted. The test results show that the use of the Taguchi method effectively optimized the composition of high-performance concrete. The slump of the prepared concrete was above 18 cm, and the slump flow was above 50 cm, indicating that it had good workability. On the other hand, the 28-day compressive strength of the hardened concretes was between 31.3-59.8 MPa. Furthermore, the analysis of variance (ANOVA) results showed that the most significant factor affecting the initial setting time of the fresh concretes was the retarder dosage, and its contribution percentage was 62.66%. On the other hand, the ANOVA results show that the most significant factor affecting the 28-day compressive strength of the hardened concretes was the water to binder ratio, and its contribution percentage was 79.05%.

• Architectural research
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• v.26 no.1
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• pp.13-20
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• 2024

This study is a research investigation into the properties of bubbles that affect the characteristics of foamed concrete during its production. The study examined the properties of bubbles based on the manufacturing conditions. To investigate these properties, the selected experimental factors included bead size, the length/diameter ratio of the bubble-generating tube, and compressed air. The experimental design used a design of experiments, and the test results were analyzed using analysis of variance. The foaming agent used to generate bubbles was AES (Alcohol Ethoxy Sulfate), and the method employed for bubble manufacture was the pre-foaming method. In the test results, a significant factor affecting the foaming rate of bubbles was the bead size; the highest foaming rate was observed when using 2mm beads. Bead size also primarily influenced the volume change of the aqueous solution, while other factors did not affect the foaming rate and volume change. None of the factors affected the change in bubble size, but compressed air was considered the main factor affecting bubble size and its change. The foaming rate and volume change of the aqueous solution showed a high correlation with each other. Spherical bubbles in the early stage eventually transformed into angular bubbles. Moreover, over time, it was observed that the bubble size increased.

• Archives of Pharmacal Research
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• v.18 no.6
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• pp.385-390
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• 1995

The analytical methods for the analysis of cyclosporine (CsA), a fluorescence polarization immunoassay (FPIA) and HPLC method, were compared in a pharmacokinetic study of two CsA soft capsule formultaions ($Sandimmun^{\circledR}$; Sandoz, $Implanta^{\circledR}$; Hanmi). Sixteen healthy volunteers completed the study and each subjected single doses ($4{\tiems}100$ mg) of the test and the reference formulations in a two-way crossover design with a one-week drug-free interval between doses. Following each administration, whole blood concentrations of CsA were monitored over a period of 24 hour by both FPIA and HPLC methods. Blood concentrations nad pharmacokinetic parameters determined by either analytical method showed large intersubject variation, with the FPIA data showing relatively higher magnitude of intersubjecte variation than the HPLC data. The blood concentrations determined by FPIA were 1.1-1.3 times higher than those determined by HPLC. There were strong and significant correlations between the two methods (r>0.83 : p<0.0001). Intersubuject variation for the $AUC_{inf}{\;}and{\;}AUC_{24hr}$ of the test formulation was slightly reduced without statistical significance (paried -t test : p>0.05 $t_{max}$ was earlier nad $C_{max}$ was slightly lower for the test formulation, $AUC_{24h}, {\;}C_{max}, {\;}T_{max}$ and MRT determined separately from the data obtained by the two methods for the two formulations were examined by analyses of variance (ANOVA) for the bioequivalency evaluation. Results of ANOVA and confidence limits of terst/reference ratios of $AUC_{24th}$, $C_{max}$, $t_{max}$ and MRT, and statistical tests indicated the bioequivalence of the two formulations (i.e., test/reference ratio was within $100{\times}20%$) except for $C_{max}$ and $t_{max}$. The mean of tmax also showed 11.1% and 9.3% differences but the detection limit were 29.2% and 29.6% as determined by FPIA and HPLC resepctively. This experiments suggest that the data yielded for the two formulations demonstrated that they were bioequivalent.

• Journal of Pharmaceutical Investigation
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• v.35 no.4
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• pp.287-293
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• 2005

The purpose of the present study was to evaluate the bioequivalence of two glimepiride tablets, Amaryl tablet (Handok & Aventis Korea, reference drug) and Mepiril tablet (Myungmoon Pharm. Co., Ltd., Korea, test drug), according to the guidelines of Korea Food and Drug Administration (KFDA). After adding an internal standard (glibenclamide) to human plasma, plasma samples were extracted using 1mL of methyl tertiary butyl ether. Compounds extracted were analyzed by reverse-phase HPLC with multiple reaction monitoring (MRM) mode analyte detection. This method for determination glimepiride proved accurate and reproducible, with a limit of quantitation of 2 ng/mL in human plasma. Twenty-four healthy male Korean volunteers received each medicine at the glimepiride dose of 2 mg in a $2{\times}2$ crossover study. There was a one-week washout period between the doses. Plasma concentrations of glimepiride were monitored by a LC-MS/MS for over a period of 12 hr after the administration. $AUC_t$ (the area under the plasma concentration-time curve from time zero to 12 hr) was calculated by the linear trapezoidal rule method. $C_{max}$ (maximum plasma drug concentration) and $T_{max}$ (time to reach $C_{max}$) were compiled from the plasma concentration-time data. Analysis of variance was carried out using logarithmically transformed $AUC_t$ and $C_{max}$. No significant sequence effect was found for all of the bioavailability parameters indicating that the crossover design was properly performed. The 90% confidence intervals of the $AUC_t$ ratio and the $C_{max}$ ratio for Amaryl/Mepiril were log 0.9583-log 1.1357 and log 1.0570-log 1.2376, respectively. These values were within the acceptable bioequivalence intervals of log 0.80-log 1.25. Taken together, our study demonstrated the bioequivalence of Amaryl and Mepiril with respect to the rate and extent of absorption.

• Journal of Preventive Medicine and Public Health
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• v.20 no.1 s.21
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• pp.67-83
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• 1987

This study relates to the problems of organizational performance in the Christian hospitals. In this study, quality of working life (QOWL), which harmonizes individual as well as organizational goals, was used as an indicator of organizational performance from the open systems view. In order to identify the behavioral factors influencing QOWL in hospitals, self-administered questionnaires were distributed to 1,926 employees who were randomly selected from fifteen Christian hospitals from August 1 to August 30, 1986. The following results were obtained: 1) All correlation coefficients between QOWL and behavioral variables were statistically significant even though their magnitude varied according to hospital size. 2) Using factor analysis, 32 variables were parsimoniously grouped into four factors: individual conflicts, group behavior, organizational characteristics and situation, and job characteristics. The proportion of variance explained by these factors ranged from 33.5% to 38.6% according to hospital size. 3) The overall effects of the four factors in the multiple logistic models ranged from 0.85 to 3.12 according to hospital size. Among three hospital models, the model for small hospitals showed the best statistical fit. 4) The most influential factor was organizational characteristics and situation with an odds ratio ranging from 1.99 to 3.02. Again, the odds ratio was the highest for small hospitals. 5) For large hospitals, the two main factor effects were statistically significant: organizational characteristics and situation, and job characteristics. For medium hospitals, all main factor effects except job characteristics were statistically significant. For small hospitals, all main factor effects except group behavior were statistically significant. However, a factor interaction effect was shown only for large hospitals where it was statistically significant. 6) To examine whether the four factors influence financial performance, the four factor scores from the two financial performance groups were compared using Mann-Whitney test. The test results showed that the organizational characteristics and situation factor score was significantly different only for small hospitals.

• Journal of the Korean Data and Information Science Society
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• v.23 no.6
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• pp.1145-1154
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• 2012

Recent research has been mostly focused on the differences of prenatal sex hormone could affect the ratio of the lengths of the second to fourth digits (2D:4D) as well as the rate of several physiological characteristics. It has been suggested that digit ratios are thought to be associated with either higher prenatal testosterone levels or greater sensitivity to androgens, or both. However, a study of person with disabilities are rare in Korea. The purpose of this study was to compare patterns of the ratio (2D:4D) of the lengths of the second and fourth digits in persons with disabilities and students without disabilities. Also, we empirically analyze the characteristics of persons with disabilities. We found that finger length ratio (2D:4D) of men with disabilities and student without disabilities were lower than women with disabilities and student without disabilities. Therefore, it could be confirmed that finger length ratio (2D:4D) is sexually dimorphic trait. There were no correlations between finger length ratio (2D:4D) and age group in persons with disabilities. Therefore, as with person without disabilities, the 2D:4D ratio was negatively associated with a growth process of persons with disabilities. Finally, There was no difference correlations between finger length ratio (2D:4D) and level of disability in persons with intellectual disabilities. From this, one possible explanation for this is that if finger length ratio (2D:4D) is related to person with disability then current classification of the level of disability deserves further investigation.

• Physical Therapy Korea
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• v.23 no.4
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• pp.55-62
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• 2016

Background: The functioning of the serratus anterior (SA) muscle is essential to normal scapulohumeral rhythm during forward flexion (FF) of the shoulder. Also, SA weakness and overuse of the upper trapezius (UT) is observed in patients with shoulder dysfunction and trapezius myalgia. We designed a combination exercise involving FF and scapular protraction with resistance (CFFSP) to activate the SA muscle and to deactivate the UT muscle. Objects: The purpose of this study was to determine whether or not CFFSP would be more effective in activating the SA muscle than FF alone and FF with scapular protraction (FFP). Methods: Nineteen subjects (12 men and 7 women) participated in this study and performed FF, FFP, and CFFSP at $120^{\circ}$. Surface electromyography was applied to the SA, UT, and pectoralis major (PM) muscles, as was one-way analysis of variance (ANOVA) with repeated measures. Statistical significance was set at .05. Bonferroni adjustment was used to counteract the problem of multiple comparisons, with a statistical level of significance of .017 (.05/3). Results: A statistically significant difference was found in relation to the three positions for the SA muscle (p<.001) and the SA/UT ratio (p=.005) using ANOVA. Significantly different results, depending on the position, were also demonstrated using the Bonferroni post-hoc test for the SA muscle ($FF=28.27{\pm}16.20$, $FFP=45.66{\pm}15.81$, and $CFFSP=62.4{\pm}27.21$) and for the SA/UT ratio ($FF=3.04{\pm}2.14$, $FFP=3.61{\pm}2.38$, and $CFFSP=5.95{\pm}3.01$). Significant differences between the three positions was not found regarding the average amplitude of SA/PM muscle ratio (SA/PM: p=.060). Conclusion: We recommend the use of CFFSP to strengthen the SA muscle at $120^{\circ}$.

• Physical Therapy Korea
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• v.29 no.1
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• pp.11-18
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• 2022

Background: Muscle activities of gluteus maximus (GM) and hamstring (HAM) have important roles in the stability and mobility of the hip joint during various functional activities including bridge and prone hip extension exercises. Objects: The purpose of this study is to investigate muscle activities of GM, multifidus (MF) and HAM during three different bridge exercises in healthy individuals. Methods: Twenty healthy subjects were participated. Electromyography device was used to measure muscle activities of GM, MF and HAM. Each subject was asked to perform three different bridge exercises with hip abduction (0°, 15°, 30°) in random order. One-way repeated measures analysis of the variance and a Bonferroni post hoc test were used. Statistical significance was set at α = 0.01. Results: The muscle activity of GM was significantly different among three conditions (hip abduction 0°, 15°, 30°) (adjusted p-value [Padj] < 0.01). The muscle activity of GM was significantly greater during bridge exercise with hip abduction 30° compared to 0° and 15° (Padj < 0.01). There was no significant difference in the muscle activity of MF and HAM muscle (Padj > 0.01). The ratio of muscle activity (ratio = GM/HAM) during bridge exercise with hip abduction 30° was significant greater compared to the hip abduction angles 0° and 15° (Padj < 0.01). Conclusion: Bridge exercise with hip abduction 30° can be recommended to selectively facilitate the muscle activity of GM and improve the ratio of muscle activity between GM and HAM.

• The Journal of Korean Physical Therapy
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• v.35 no.1
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• pp.13-18
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• 2023

Purpose: The purpose of this study was to investigate the effects of posterior oblique sling activation on the muscle activities of the gluteus maximus (GM), multifidus (MF), and biceps femoris (BF) during three different prone hip extension exercises in healthy male individuals. Methods: Twenty healthy subjects participated in this study. An electromyography device was used to measure the muscle activities of the GM, MF, and BF. Each subject was asked to perform three different prone hip extensions as follows: [1) Prone hip extension with knee flexion + hip abduction 30°; PHE1, 2) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125°; PHE2, 3) Prone hip extension with knee flexion + hip abduction 30° and shoulder abduction 125° with 1kg loading; PHE3, in random order. A one-way repeated measures analysis of the variance and a Bonferroni post hoc test were used to analyze the results. The statistical significance was set at α=0.01. Results: The muscle activity of the GM was significantly different between the three positions (P_adj<0.01). The muscle activity of the GM was significantly greater during PHE3 compared with PHE1 and PHE2 (P_adj<0.01). The BF muscle activity was significantly lower during PHE3 compared with PHE1 and PHE2 (P_adj< 0.01). There was no significant difference in the muscle activity of the MF (P_adj<0.01). The ratio of the muscle activity (ratio=GM/BF) during PHE3 was significantly greater compared to PHE1 and PHE2 (P_adj< 0.01). Conclusion: The GM activity and GM/BF ratio during the PHE3 exercise were significantly greater compared to that during PHE1 and PHE2. Therefore, the PHE3 exercise could be recommended as a selectively effective GM activation exercise while decreasing the muscle activity of the BF.