• Journal of the Korea Concrete Institute
• /
• v.19 no.4
• /
• pp.411-420
• /
• 2007

The applicability of headed bars in exterior beam-column joints under reversed cyclic loading was investigated. A total of ten pullout tests were first performed to examine pullout behavior of headed bars subjected to monotonic and cyclic loading with test variables such as connection type between head and bar stem (weld or no weld), loading methods (monotonic or cyclic loading), and head shape (small or large circular head and square head). Two full-scale beam-column joint tests were then performed to compare the structural behavior of exterior beam-column joints constructed using two different reinforcement details: i.e. $90^{\circ}$ standard hooks and headed bars. Both joints were designed following the recommendations of ACI-ASCE Committee 352 for Type 2 performance: i.e. the connection is required to dissipate energy through reversals of deformation into inelastic range. The pullout test results revealed that welded head to the stem did not necessarily result in increased pullout strength when compared to non-welded head. Relatively large circular head resulted in higher peak load than smaller circular and square head. Both beam-column joints with conventional $90^{\circ}$ hooks and headed bars behaved similarly in terms of crack development, hysteresis curves, and peak strengths. The joint using the headed bars showed better overall structural performance in terms of ductility, deformation capacity, and energy dissipation. These experimental results demonstrate that the headed bars using relatively small head can be properly designed far use in external beam-column joint.

• Journal of the Korea Convergence Society
• /
• v.10 no.12
• /
• pp.337-343
• /
• 2019

The need for preparation for old life has been further increased due to the increase of the elderly population and changes in economic conditions today. The purpose of this study is to analyze the relationship between income instability and the degree of preparation for old life and satisfaction of current life. The key variables were extracted through prior study review. And the data collected through the survey were statistically analyzed with a structural equation model. The analysis found that the indirect effect of the current income risk on the satisfaction of current life through the preparation for old life had a significant negative effect under the statistically significant level of 0.05. However, it was found that the direct effects of current income risk on the satisfaction of current life were not statistically significant. An additional analysis was conducted by dividing the age, the number of dependents by two groups respectively. To summarize the results, preparation for old life played a significant role as a prerequisite for improving the satisfaction of current life. And the variability(risk) of current income played an important role in preparing for old life. At this time, the degree of relevance between the factors(potential variables) differed somewhat between the two groups. The results of this analysis will be meaningful in providing basic source of data to prepare for a satisfactory life in each individual's current situation. This study, meanwhile, has limitations that have only been done with cross-sectional analysis and would like to analyze time-series changes in the future.

• Journal of the Korea Convergence Society
• /
• v.11 no.7
• /
• pp.97-104
• /
• 2020

The Purpose of this paper was to explore the effect of hearing impairment on HRQOL in Korean elders. We carry out a cross-sectional analysis using nationally representative data from the KNHANES, 2018. A total of 528 elders who had hearing impairment were included. Statistical analysis was performed using SPSS 25.0, χ²-test, t-test, correlation, and regression analysis to confirm the quality of life, and the influencing factors. There were significant differences in HRQOL according to gender, age, education, marital status, income, occupation, number of household members, tinnitus, number of comorbidities, smoking status, alcohol drinking status, subjective health status, regular exercise, restriction of activity, depressive mood and perceived stress. The results indicated that age, BMI and number of comorbidities had a significant negative association with HRQOL. In addition, marital status, number of comorbidities, body mass index, subjective health status, regular exercise, restriction of activity and perceived stress were predictors of life quality in elders with Hearing Impairment and the variable in the health-related quality of life was explained by 37.3%. In order to improve the HRQOL of elders with hearing impairment, multidisciplinary efforts and development of educational programs are required.

• The Korean Journal of Financial Management
• /
• v.24 no.2
• /
• pp.81-111
• /
• 2007

The agency relationship between managers and shareholders has the potential to influence decision-making in the firm which in turn potentially impacts on firm characteristics such as value and leverage. Using an agency framework, we examine the relation between ownership structure and capital structure during post-IMF period. We used the balanced panel data for 378 korean listed companies during the 1999-2005. The panel data sets consist of time-series observation on each of 378 cross-sectional units. The results indicate a non-linear U-shaped relation between the level of managerial share ownership and leverage with the relation reaching a minimum at 58.48 per cent of management share ownership. As managerial share ownership increase from a low level, managers have incentive to reduce the debt level for decreasing the financial risk, resulting in a lower lever of debt. However, when corporate managers hold a significant proportion of a firm's shares, managers have incentive to increase the debt level for leverage effects, resulting in a higher lever of debt.

• Culinary science and hospitality research
• /
• v.20 no.6
• /
• pp.175-189
• /
• 2014

This study was intended to provide fundamental data concerning franchising companies' characteristics and performance in foodservice business by employing financial data from the firms' IDS(Information Disclosure Statements). Multiple regression analysis method was used to identify any correlations among franchising size, marketing competency, operational characteristics, and performance according to technique based upon 169 IDS data as of 2013. In terms of franchisor size and performance, the number of company-operated stores had statistically significant corelation with sales, net income, the total number of stores, and the number of franchisees. With respect to marketing competency and performance, advertising expenses showed statistically significant correlation with sales, the total number of stores, promotion expenses with sales, net income, and the total number of stores. On the other hand, there was no statistically significant correlation with current year's net income. At last, present study found significant correlations among business years, sales, current year's net income, and the total number of stores by regarding operational characteristics and performance, but there was no significant correlation between brands and performance. This study is cross-sectional study which is a limitation to be overcome in further studies. In addition, it is required to review the possibility for franchise management style to contribute to expanding the Korean traditional foods.

• The Korean Journal of Rehabilitation Nursing
• /
• v.4 no.2
• /
• pp.219-231
• /
• 2001

The purpose of this study was to investigate the relationship among percieved social support, hope and quality of life of the cancer patients and to gain the baseline data for development of nursing intervention program for promoting quality of life in cancer patients. The design of this study was a cross sectional correlational survey. The subjects were 220 out and in-cancer patients in 5 general hospitals in Pusan. The data were collected from July 2 to August 1, 2001. The instruments were the Percieved social support scale(16 items, 5 point scale) had developed by Tae(1986), Hope scale(12 items, 4point scale) developed by Nowotny(1989) and Quality of life scale(31 items, 10 point scale) developed by Tae et al.(2000). The data was analyzed by the SPSS/PC+ program using frequency & percentage, item mean & standard deviation, t-test, ANOVA & Scheffe test, Pearson's correlation coefficient. The results of this study was as follows: 1) The item mean score of quality of life was $6.05{\pm}1.16$ (range 0-10). The highest score of subarea of the quality of life was the spiritual wellbeing area ($7.09{\pm}1.63$) and the lowest score was social wellbeing area ($5.53{\pm}1.65$). The mean score of perceived social support was $52.65{\pm}10.32$ (최저 1, 최고 80). The mean score of family support was $32.71{\pm}6.66$ (range 1-40) and the mean score of medical team support was $19.93{\pm}5.95$ (range 1-40). The mean score of Hope was $37.02{\pm}5.64$ (range 1-48). 2) There were statistically significant difference in the score of quality of life according to the life effect of religion(F=3.97, p=0.00), treatment method(F=2.94, p=0.01), area of diagnosis(F= 3.48, p=0.01), stage of disease (F=13.74, p=0.00). 3) There was significant correlation between perceived social support(r=0.44, p=0.000 ; family support ; r=0.334, p=0.000, medical support; r=0.395, p=0.000), hope(r=0.563, p=0.000) and quality of life. In conclusion, there was a significant relationship among perceived social support, hope and quality of life. Therefore perceived social support, hope intervention programs should be developed to improve the quality of life in cancer patients.

• Journal of the Institute of Electronics Engineers of Korea SD
• /
• v.37 no.11
• /
• pp.18-24
• /
• 2000

(Ba,Sr)$TiO_3$ thin films have attracted great interest as new dielectric materials of capacitors for ultra-large-scale integrated dynamic random access memories (ULSI-DRAMs) such as 1 Gbit or 4 Gbit. In this study, inductively coupled $BCl_3/Cl_2/Ar$ plasmas was used to etch (Ba,Sr)$TiO_3$ thin films. RF power/dc bias voltage=600 W/-250 V and chamber pressure was 10 mTorr. The $Cl_2/(Cl_2+Ar)$ was fixed at 0.2 the (Ba,Sr)$TiO_3$ thin films were etched adding $BCl_3$. The highest (Ba,Sr)$TiO_3$ etch rate is $480{\AA}/min$ at 10 % $BCl_3$ to $Cl_2/Ar$. The change of Cl, B radical density measured by optical emission spectroscopy(OES) as a function of $BCl_3$ percentage in $Cl_2/Ar$. The highest Cl radical density was shown at the addition of 10% $BCl_3$ to $Cl_2/Ar$. To study on the surface reaction of (Ba, Sr)$TiO_3$ thin films was investigated by XPS analysis. Ion bombardment etching is necessary to break Ba-O bond and to remove $BaCl_2$. There is a little chemical reaction between Sr and Cl, but Sr is removed by physical sputtering. There is a chemical reaction between Ti and Cl, and $TiCl_4$ is removed with ease. The cross-sectional of (Ba,Sr)$TiO_3$ thin film was investigated by scanning electron microscopy (SEM), the etch slope is about 65~70$^{\circ}$.

• Journal of Periodontal and Implant Science
• /
• v.50 no.2
• /
• pp.74-82
• /
• 2020

Purpose: The aim of this cross-sectional study was to investigate the effect of scaling and root planing (SRP) on the expression of anti-inflammatory cytokines (interleukin [IL]-4, IL-9, IL-10, and IL-13) in the gingival crevicular fluid (GCF) of electronic cigarette users and non-smokers with moderate chronic periodontitis (CP). Methods: Electronic cigarette users and non-smokers with CP were included in the study. Full-mouth plaque and gingival indices, probing depth (PD), clinical attachment loss (CAL), and marginal bone loss (MBL) were assessed. The GCF was collected, and its volume and levels of IL-4, IL-9, IL-10, and IL-13 were assessed. These parameters were evaluated at baseline and 3 months after SRP. The sample size was estimated, and comparisons between groups were performed. P<0.05 was considered to indicate statistical significance. Results: Thirty-six electronic cigarette users (47.7±5.8 years old) and 35 non-smokers (46.5±3.4 years old) with CP were included. At baseline, there were no differences in plaque index (PI), PD, CAL, MBL, and GCF IL-4, IL-9, IL-10, and IL-13 between electronic cigarette users and nonsmokers. At the 3-month follow-up, there were no significant differences in PI, gingival index (GI), PD, CAL, and MBL in electronic cigarette users compared to baseline, while there were significant reductions in PI, GI, and PD among non-smokers. At the 3-month follow-up, GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly elevated in both groups (P<0.05) compared to baseline. The increases in GCF IL-4, IL-9, IL-10, and IL-13 levels were significantly higher in non-smokers (P<0.05) than in electronic cigarette users at the 3-month follow-up. Conclusions: Levels of GCF IL-4, IL-9, IL-10, and IL-13 increased after SRP in electronic cigarette users and non-smokers with CP; however, the anti-inflammatory effect of SRP was more profound in non-smokers than in electronic cigarette users.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.28 no.1
• /
• pp.95-105
• /
• 2001

The present study was designed to compare morphological and structural relationships between basicranial measurements such as MCF angulation (Ar-SE-ptm), saddle angle (N-S-Ba, N-S-Ar) and facial structures including types of malocclusion. Twenty six children with Class III whose longitudinal headfilms were available from 7 to 12-year-old, and also 26 cross-sectional headfilms at each ages of 8, 9, 10 and 11 with Class I were selected for the investigation. Cephalometric measurements such as Ar-SE-ptm, N-S-Ba, N-S-Ar, N-SE-Ar, SNA, SNB, N-S/PM vert, CP/PM vert, $\underline{1}/FH$ plane, and $N-perp/\underline{1}$ were measured. Morphologic relationships and pattern of changes in facial structures in relation to the changes of MCF and saddle angle in both malocclusion types were analysed statistically employing ANOVA, t-test and Pearson correlation. Results suggest that the MCF rather than the saddle angle in children with Class I and III is more closely related with various facial structures and with their changes. It may be, therefore, suggested that the MCF be one of the biologically meaningful measurements in determining structural relationships between cranial base and facial complex including types of malocclusion. In addition, the MCF and its correlated facial structures in children with Class III, interestingly, showed somewhat marked changes between the ages of 9 and 11.

• Journal of the korean academy of Pediatric Dentistry
• /
• v.47 no.4
• /
• pp.368-376
• /
• 2020

The primary maxillary second molars usually have three roots. However, an additional root located mesiopalatally is occasionally observed. This study aimed to determine the relationship between a mesiopalatal root of primary maxillary second molars and an abnormal eruption pattern of maxillary second premolars. The study was performed on cone beam computed tomography images taken from 916 children who visited the Dental Hospital of Kyung Hee University from 2010 to 2018. 744 serial cross-sectional cone beam computed tomography images were evaluated. The overall incidence of the mesiopalatal root of primary maxillary second molars was 3.2% (n = 24) and the abnormal eruption pattern of maxillary second premolars was 19.2% (n = 143). Especially, patients with the mesiopalatal root of primary maxillary second molars were significantly more likely to have the abnormal eruption pattern on maxillary second premolars (p = 0.000). The odds of the abnormal eruption pattern of maxillary second premolars with the mesiopalatal root of primary maxillary second molars was about 13 times higher than those without. The eruption pattern of the permanent successor should be carefully observed and treated if the mesiopalatal root of primary maxillary second molar is existent.