• Proceedings of the Korea Concrete Institute Conference
• /
• 2003.05a
• /
• pp.878-883
• /
• 2003

To modify some problems of ACI shear provisions, ultimate shear strength equation considering size effect and arch action to compute shear strength in high-strength concrete beams without stirrups is presented in this research. Three basic equations, namely size reduction factor, rho factor, and arch action factor, are derived from crack band model of fracture mechanics, analysis of previous some shear equations for longitudinal reinforcement ratio, and concrete strut described as linear function in deep beams. Constants of basic equations are determined using statistical analysis of previous shear testing data. To verify proposed shear equation for each variable, namely d, , ρ, f/sub c/' and aid, about 250 experimental data are used and proposed shear equation is compared with ACI 318-99 code, CEB-FIP Model code, Kim & Park's equation and Zsutty's equation. While proposed shear equation is simpler than other shear equations, it is shown to be economical predictions and reasonable safety margin. Hence proposed shear strength equation is expected to be applied to practice shear design.

• Proceedings of the KIPE Conference
• /
• 2001.07a
• /
• pp.669-672
• /
• 2001

Generally, previous converter is divided into two categories to get high power factor and good output regulation. These two categories can be combined a category with a main switch. These converter is called Single Stage PFC Converter. This approach has good electrical characteristics of high power factor and fast output voltage regulation. The cost and size are important factor to design the converter in low power system. Even single stage can reduce the size and cost, but this approach needs to have additional circuit like control, PWM circuit. To improve these demerits, Top switch is one of good choice In reduce and size in low power single stage converter. Because it has the ability of current limit, thermal protection, oscillator, control circuit as well as a main switch ability.

• Journal of Korean Society of Water and Wastewater
• /
• v.20 no.6
• /
• pp.837-848
• /
• 2006

This paper presents the test results of biological aerated filtration(BAF) process to replace activated sludge process by enhancing treated effluent quality and reducing the costs. In BAF process both BOD and SS compounds in wastewater are degraded and removed by biological reaction and filtration. Upflow BAF with expanded polypropylene media and downflow BAF with ceramic media were used to investigate the effects of hydraulic and organic loads on effluent quality. As a result, in BAF processes which has different media, upflow BAF reactor shows 5% higher efficiency than downflow BAF and this phenomena caused by backwashing methods and operational conditions. The results of influence factors analyzed by Factor Analysis Method in BOD and SS treatment efficiency are the size of media, hight of media bed and type of media. The quantitative effects of media size are 5.73% in TBOD, 5.78% in SBOD and 7.65% in TSS, so we confirmed the main factor is media size.

• Fashion & Textile Research Journal
• /
• v.19 no.6
• /
• pp.795-803
• /
• 2017

This research aimed to figure out the effects of physical features such as BMI, garment size and socio-psychological factors such as self-esteem and depression on the body management. A survey was conducted for women in their 40's and 50's. The participants in this study consisted of 197 women recruited in Daegu and the surrounding areas. Statistical analysis including factor analysis, ANOVA, cluster analysis and regression was done using SPSS 23.0 to analyze the results. Among 3 clusters divided by BMI, normal group showed higher body cathexis compared with overweight group and obesity group. S-size group showed higher body cathexis rather than M, L-size groups. L-size group showed higher scores in nonsurgical body management factor. Self-esteem(+)/depression(-) group showed highest body cathexis among 4 groups clustered by self-esteem and depression levels. On the other hand, self-esteem(-)/depression(+) group showed the lowest body cathexis and highest surgical body management and nonsurgical body management factors. This result meant that the lower in self-esteem and the higher in depression, body cathexis decreased and desire for body management increased. As the results of analysis of the effects of BMI, garment size, self-esteem, depression level on body management, depression was a significant factor on surgical body management; depression and garment size were critical factors on nonsurgical body management.

• Journal of the Korean Society of Safety
• /
• v.32 no.4
• /
• pp.16-21
• /
• 2017

The sprinkler system is a basic fire extinguishing system that uses water as an extinguishing agent. In order to evaluate the fire extinguishing performance of the sprinkler system, information such as the discharge angle, discharge speed, discharge pressure, flow rate, and water droplet size of the installed head are required. However, there is a lack of research on droplets size compared to other requirements. In this study, to evaluate the extinguishing characteristics of sprinkler system, the droplet size distribution was measured for various types of sprinkler heads actually used. The size of the droplet was measured using laser diffraction method. The 50% cumulative volume distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the distribution ($D_{v50}$) according to discharge coefficient(K factor) was $540{\mu}m{\sim}695{\mu}m$ for K50, $542{\mu}m{\sim}1,192{\mu}m$ for K80, $980{\mu}m{\sim}1,223{\mu}m$ for K115 and $1,188{\mu}m{\sim}1,234{\mu}m$ for K202. Based on the measured results, the vaeiance of the droplet particle distribution and the Rosin-Rammler index value are presented. As a result of the fire simulation with FDS, it was confirmed that the performance difference occurs according to the water droplet size distribution even when the same amount of water is used. Therefore, the extinguishing performance of the sprinkler system should be evaluated considering the droplet size distribution according to the sprinkler head type.

• Journal of Preventive Medicine and Public Health
• /
• v.20 no.1 s.21
• /
• pp.67-83
• /
• 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 Korean Public Health Nursing
• /
• v.32 no.3
• /
• pp.451-467
• /
• 2018

Purpose: The aim of this study was to determine the related factors for psychological crises in Korean middle aged adults. Methods: RISS, KISS, National Assembly Digital Library, CINAHL, and PubMed were searched for relevant articles published until October 3, 2016. Finally, a total of 23 studies were included. Meta-analysis of the studies was conducted using Comprehensive Meta-Analysis 3.0 software to calculate the effect size. Results: The related variables of psychological crisis were categorized into 23 variables and 5 factor groups. The effects size (ES) of the overall defensive variables was -0.28. In the defensive factors, the psychological factor (ES=-0.67), followed by cognitive and behavioral factor (ES=-0.34), physical factor (ES=-0.31), and social relational factor (ES=-0.29) had the greatest effect on psychological crises. The effects size of the overall risk variables was 0.48. In the risk factors, the physical factor (ES=0.61) had the greatest effect on psychological crises, followed by the psychological factor (ES=0.53), and cognitive and behavioral factor (ES=0.10). Conclusion: An intervention program is needed to strengthen the defensive factors and reduce the risk factors for psychological crises of Korean middle aged adults.

• Structural Engineering and Mechanics
• /
• v.32 no.3
• /
• pp.459-475
• /
• 2009

This paper presents analytical methodologies for remaining life prediction of plain concrete structural components considering tension softening and size effects. Non-linear fracture mechanics principles (NLFM) have been used for crack growth analysis and remaining life prediction. Various tension softening models such as linear, bi-linear, tri-linear, exponential and power curve have been presented with appropriate expressions. Size effect has been accounted for by modifying the Paris law, leading to a size adjusted Paris law, which gives crack length increment per cycle as a power function of the amplitude of a size adjusted stress intensity factor (SIF). Details of tension softening effects and size effect in the computation of SIF and remaining life prediction have been presented. Numerical studies have been conducted on three point bending concrete beams under constant amplitude loading. The predicted remaining life values with the combination of tension softening & size effects are in close agreement with the corresponding experimental values available in the literature for all the tension softening models.

• The Research Journal of the Costume Culture
• /
• v.28 no.5
• /
• pp.639-651
• /
• 2020

This study utilized data to classify and characterize the body types of plus-size adult men aged in their 30s and 40s. Diversity is an important factor in the era of inclusive design, and discussion about size diversity to include the plus size should be accommodated. Data from 493 adult men classified as obese (with a World Health Organization criterion ≥25 BMI) were used for the analysis. The results of the study are as follows. Six independent factors were extracted using factor analysis for cluster analysis, which were then classified into five types. Type 1 (29.01%) was identified as body type I with the smallest degree of obesity. Type 2 (15.4%) was identified as body type Y with wide shoulders and a thin waist. Type 3 (14.2%) was the largest body volume (body type O), while the fourth (19.27%) identified as body type H has a large height and upper body. Lastly, type 5 (22.11%) has a long lower body and a slim abdomen, referred to as body type X. This study presents a basis for the development of various clothing sizes utilizing the body shape characteristics of plus-size men in their 30s and 40s. Follow-up research is needed to develop patterns for plus size men and to design various products.

• Radiation Oncology Journal
• /
• v.14 no.3
• /
• pp.237-244
• /
• 1996

Purpose : The accurate dosimetry of independent collimator equipped for 6MV and 15MV X-ray beam was investigated to search for the optimal correction factor. Materials and Methods : The field size factors, beam quality and dose distribution were measured by using 6MV, 15MV X-ray Field size factors were measured from $3{\times}3cm^2$ to $35{\times}35cm^2$ by using 0.6cc ion chamber (NE 2571) at Dmax. Beam qualities were measured at different field sizes, off-axis distances and depths. Isodose distributions at different off-axis distance using $10\times10cm^2$ field were also investigated and compared with symmetric field. Result: 1) Relative field size factors was different along lateral distance with maximum changes in $3.1\%$ for 6MV and $5\%$ for 15MV. But the field size factors of asymmetric fields were identical to the modified central-axis values in symmetric field, which corrected by off-axis ratio at Dmax. 2) The HVL and PDD was decreased by increasing off-axis distance. PDD was also decreased by increasing depth For field size more than $5{\times}cm^2$ and depth less than 15cm, PDD of asymmetric field differs from that of symmetric one ($0.5\~2\%$ for 6MV and $0.4\~1.4\%$ for 15MV). 3) The measured isodose curves demonstrate divergence effects and reduced doses adjacent to the edge close to the flattening filter center was also observed. Conclusion . When asymmetric collimator is used, calculation of MU must be corrected with off-axis and PDD with a caution of underdose in central axis.