• Korean Journal of Applied Biomechanics
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• v.22 no.1
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• pp.75-82
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• 2012

The purpose of this study was to suggest the proper shaft and head fitting methods of the golf club to increase the flight distance of the golf ball. Rotations per minute of the golf ball(RPM), ratio of Ball speed to club head speed(T-Ratio) and launch angle right after impact(LA), which are directly related to ball flight distance, were measured using Spectra with shutter speed of 1/1000sec at the constant head speed of 95mph which was controlled by robot golf swing machine. In order to investigate the effect of club shaft to the 3 selected variables, 10 shafts were used to make ten test clubs with one controlled club head which is the most commonly used by golf players. To measure the effect of the club head to the 3 selected variables, 6 golf club heads which are most commonly used by golfers were selected to make 6 test clubs with a controlled shaft which is one of the best known by players. The shafts and the heads were identified by statistical analysis to increase or decrease the RPM, T-ratio and LA. A proper fitting method of the selected shafts and the club head was suggested to increase the ball flight distance in golf.

• The Journal of Korean Physical Therapy
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• v.30 no.2
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• pp.58-62
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• 2018

Purpose: This study evaluated the effects of respiratory muscle training on respiratory function, balance, and activities of daily living (ADL) in patients with stroke. Methods: The study included 21 patients with stroke, divided into the experimental group and control group. Both groups underwent traditional physical therapy once a day for 30 minutes, five times weekly for 6 weeks. The experimental group underwent additional respiratory muscle training once a day, five times a week during the study period. Maximal inspiratory pressure (MIP), maximal expiratory pressure (MEP), Berg balance scale (BBS), and Korean-modified Barthel index (K-MBI) were measured before and after the study period. For statistical analysis, paired t-test was used to compare the difference between the pre and post values. Independent t-test was used compare the differences between groups. Results: Both groups had significantly improved MIP, MEP, BBS, and K-MBI scores after the study period. The experimental group had significantly improved MIP, MEP, BBS, and K-MBI scores. Conclusion: These results suggest that respiratory muscle training improves respiratory function, balance, and ADL in patients with stroke.

• Journal of Korean Society for Quality Management
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• v.44 no.3
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• pp.617-638
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• 2016

Purpose: The purpose of this study is to propose useful suggestions by analyzing difference of financial performance between "Excellent Quality Competitiveness Enterprise(EQCE)" awarding companies and all the manufacturing companies during the period 2003-2014 and by testing the moderating effects of performance year. Methods: This paper perform the longitudinal study during the period 2003-2014. The collected data through list of National Quality Award and financial report of CRETOP were analyzed using independent-sample t-test, paired-sample t-test, one way ANOVA and empirical analysis. Results: The results of this study are as follows; EQCE showed higher growth rate than all the companies until 2008, but profitability, stability, and activity are not significantly different between the both. Therefore EQCE have partial influences on growth rate among several financial performance measures until 2008. Since 2009 there are no differences. The effects of EQCE on financial performance are different by the year. Conclusion: EQCE award system was a meaningful promotion method to enhance good financial performance through encouraging quality management for the manufacturing companies until 2008, But since 2009 it is expected to lose its role as a promoting tool for quality management and performance excellence. Therefore new way of thinking for EQCE, as a national quality award system, is necessary; changing awarding system, award criteria, or etc.

• International Journal of Highway Engineering
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• v.15 no.2
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• pp.131-138
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• 2013

PURPOSES : The intents of the study are to identify the accident factors and to demonstrate the potentials of tobit model as a tool to study the number of accidents on arterial roads segments. METHODS : This paper uses a tobit regression as a methodology to analyze the factors affecting the number of accidents. In pursuing the above goal, this study gives particular attentions to analyzing the data of 2,446 accidents (1,610 in major arterial roads and 836 in minor arterial roads) occurred on arterial roads in 2007 to 2010. RESULTS : First, 3 accident models which were classified by total arterial roads, major arterial roads and minor arterial roads, and were all statistically significant were developed. Second, the exclusive right-turn lane as common variable, and the number of accident, traffic volume, number of lanes, link length, rate of median, number of entrances, number of pedestrian crossings, number of curves, number of bus stops and exclusive left-turn as specific variables of the models were selected. Finally, the paired sample t-test could not be rejected the null hypotheses of three types of models. CONCLUSIONS : Using data from vehicle accidents on arterial roads, the estimation results show that many factors related to roadway geometrics and traffic characteristics significantly affect to the number of accidents.

• Proceedings of the KWS Conference
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• 2005.11a
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• pp.82-84
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• 2005

Fatigue assessment of welded structure is very sensitive to the method of local stress determination. Normally, hot spot stress which is surface stress extracted from 0.5t, 1.5t away from weld toe is widely used to obtain local stress. However, this method has a lot of limitation in the evaluation of fatigue strength. Therefore, mesh has to comply with strict requirements since stress extracted from this method strongly rely on mesh size and element types. And that method does not cover the stress gradient through thickness direction since only surface stress is considered. Recently, new method to obtain local stress is proposed, which is structural stress. This method has an advantage, which is mesh intransitiveness and covering the effect of both bending and axial stress in local area. In this paper, fatigue test data for various welded joints was analyzed to review the reliability of structural stress. As a result, it is verified that S-N curve using structural stress guaranteed single master curve for various joint type and testing condition.

• Journal of the Korean Society for Heat Treatment
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• v.25 no.3
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• pp.138-145
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• 2012

An ${\alpha}$-Ferrite (Fe) powder dispersed with 4 vol.% of $Al_2O_3$ was successfully produced by a simple miling at 210 K with a mixture of $Fe_2O_3$, Fe and Al ingredient powders, followed by 2 step high temperature consolidation: Hot Pressing (HP) at 1323 K and then Hot Isostatic Pressing at 1423 K. The microstructure of the consolidated material was characterized by standard metallographic techniques such as XRD (X-ray Diffraction), TEM and STEM-EDS. The results of STEM-EDS analysis showed that the HIPed materials comprised a mixture of pure Fe matrix with a grain size of ~20 nm and $Al_2O_3$ with a bimodal size distribution of extremely fine (~5 nm) and medium size dispersoids (~20 nm). The mechanical properties of the consolidated materials were characterized by compressive test and micro Vickers hardness test at room temperature. The results showed that the yield strength of the ODS (Oxide Dispersion Strengthened) Fe alloy are as much as $674{\pm}39$ MPa and the improvement of the yield strength is attributed to the presence of the fine $Al_2O_3$ dispersoid.

• Journal of Veterinary Clinics
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• v.17 no.2
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• pp.381-387
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• 2000

Efficacy of a 1% solution of sodium carboxymethylcellulose (SCMC) infu7ed into the peritoneal cavity of dogs was evaluated for prevention of intraperitoneal adhesion, resulting from operations of the reproductive tract. Saline-treated deles (n = 5) were controls that underwent ventral midline celiotomy, and adhesions were cleated by incision and scraping about 5 cm segment of each uterine horn. Saline (7 ml/kg of body weight) was then infused into the peritoneal cavity. Others (n = 5) were treaded similarly to the saline-treated dogs. except that 1% SCMC :solution (7mH/kg of body weight) was infused into the peritoneal cavity. This group was studied to determine whether SCHC would prevent the adhesions in the peritoneal cavity, especially in the uterine horn model. Abdominal adhesions were evaluated and an adhesion severity score was assigned to each dog on the basis of severity of adhesions. At the time of necropsy. the mean adhesion score in the saline treated group was $2.65{\pm}0.22.$ In contrast, adhesion formation in the SCMC treated group was less ($mean score =1.70{\pm}0.26$). Statistic71 analysis was performed using the grouped t-test and paired t-test. A significanlty lower adhesion score was observed in dogs given SCMC than in the saline treated group (P<0.01). In summary, SCMC significantly reduced adhesion formation in the dog uterine horn model. The results of this study suggest that application of 1% SCMC solution, following various reproductive pelvic surgery, will present the adhesions.

• Proceedings of the Korea Concrete Institute Conference
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• 2008.04a
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• pp.605-608
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• 2008

We have studied statistically about quality difference of Blast furnace slag Type Ⅲ that affects carbonation of concrete. According to KS F 2563 blast furnace slag was classified 3 types. Type Ⅲ blast furnace slag(specific surface area is $4000cm^2/g$) from different providers with Type A, the B and the C. The statistical technique was applied to exclude error of engineering judgement. T test and F test were used among 3 groups to investigate statistical meaning. The effect which on the quality of blast furnace slag type Ⅲ that affects carbonation of concrete is significant.

• Journal of the Korean Institute of Educational Facilities
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• v.24 no.6
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• pp.3-10
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• 2017

The efforts for sustainable development in building construction is widely applied by global organizations, governments, etc. However, according to the researchers, if the green rating systems on the building, it is reported that construction costs and durations are increased compared to conventional buildings. In this respect, the objective of this study is to identify the construction costs between LEED and non-LEED buildings. The scope of this study is limited in 21 university buildings of Canada. The methodology is as follows: First, the data of LEED and non-LEED buildings are collected in every university building. Second, the average construction costs per square meter is collected and normality check is conducted. Third, to identify statistical significance, the difference of average construction costs is analyzed by using T-test. As a result, it is concluded that the construction costs of LEED buildings are increased by approximately 3.8% more than non-LEED buildings. In the future, the results of this study can be applied to analyzing the additional costs according to the LEED grade in educational buildings.

• Korean Journal of Air-Conditioning and Refrigeration Engineering
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• v.23 no.8
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• pp.549-555
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• 2011

For a $CO_2$ one-stage twin rotary compressor, a T-shaped suction port was used to effectively supply the suction gas stream into two individual suction chambers of the twin cylinders. Suction gas pulsations were observed in the pressure sensor signals and these were simulated by using the acoustic modeling of Helmholz resonators in parallel. The module of acoustic modeling was combined to a computer simulation program for the compressor performance. Validation of the simulation program has been carried out for a bench model compressor in a compressor calorimeter. Cooling capacity and the compressor input power were reasonably well compared between the simulation and the calorimeter test. Particularly, good agreement on P-V diagram between the simulation and the test was obtained.