• Journal of Korean Association for Spatial Structures
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• v.5 no.3 s.17
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• pp.65-74
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• 2005

An analytical model was developed to investigate the flexural behavior of a pultruded fiber-reinforced plastic deck of rectangular unit module. The model is based on first-order shea. deformable plate theory (FSDT), and capable of predicting deflection of the deck of arbitrary laminate stacking sequences. To formulate tile problem, two-dimensional plate finite element method is employed. Numerical results are obtained for FRP decks under uniformly-distributed loading, addressing the effects of fiber angle and span-to-height ratio. It is found that the present analytical model is accurate and efficient for solving flexural behavior of FRP decks. Also, as the height of FRP deck plate is higher, the necessity of higher order Shear deformable plate theory(HSDT) is announced, not the FSDT in the plate analysis theory.

• Journal of Korean Society for Geospatial Information Science
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• v.23 no.3
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• pp.49-55
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• 2015

Current medical delivery system in Korea has been distinguished into three types; primary medical facilities, secondary facilities, and tertiary facilities since 1989. This system prevents the waste of medical resources along with the maintenance of balance according to the medical treatment subjects. However, it is inevitable that the imbalance of the medical services among regions has been generated due to the concentration of the medical facilities on large cities. In this regard, this study attempted to evaluate the quality of the primary medical services, emphasizing accessibility and convenience targeting Jinju city, a small and medium-sized city, based on the distribution characteristics of the space. The study results show that cohesion index about the spatial distribution of the primary care facilities was 0~0.25. It conducted a correlation analysis between the location of the hospitals and users, based on the study results. Finally, it is demonstrated the correlation between the location of the hospitals and users tended to be low, while, the cohesion of the Oriental medicine clinics was high in other treatment subjects, and the accessibility to the Oriental medicine clinics was the highest because most Oriental medicine clinics were distributed to the places where users were many. However, on account that the locations of the medical facilities and users were varied in other treatment subjects except for the Oriental medicine clinics, problems were generated in terms of the accessibility. Therefore, it is judged that the preparation of the measures to improve the selection of lots in consideration of users, who use the primary medical services, is required.

• Korean Journal of Poultry Science
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• v.18 no.1
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• pp.33-42
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• 1991

In order to study effects of the 9round charcoal and organic acid on the egg production, White Leghorn strain(Hyline) layer of 113 week-old were fed control diet during a week of previous feeding and subsquent experimental diets during 12 weeks of experimental feeding . The experimental diets were the basal (control) diet composed of mainly corn-soybean meal, diet (CPB) substituted 0.5％ of ground charcoal with the defatted rice bran of the control, diet (PWV) added 0.1 mM(based on the acetic acid) of wood vinegar in the CPD and diet(PFA) added 0.1 mM (based on the acetic acid) of fermented acetic acid in the CPD. During experimental feeding period, birds (ed control, CPD and PWV diets showed similar feed intake which was shown a decreasing tendency in birds fed PFA diet as the passage of experimental feeding period. Birds fed experimental diets containing ground charcoal were tended to increase egg weight (g/egg) , while which of birds fed CPD was higher(P＜0.05) than that fed control diet. Chicks fed the control, CPD and PWV diets produced 75.9, 75.0 and 75. 9％ of egg, respectively, which were significantly(P＜0.05) higher than those of birds fed PFA. Daily egg mass(g/bird) were reached to 48.6, 49.9 and 49.5g i,1 layer fed the control, CPD and PWV diets, respectively, showing an increasing tendency in layer fed CPD and PWV compared with those of birds fed control, which were significantly (P＜0.05) higher than those of birds fed PFA . Although the effect of experimental diets on the feed efficiency (egg/feed) was not found, which was shown an increasing tendency in layer fed CPD compared with those in control diet. Compared with the incidence of cracked or shelless eggs in birds fed control diet, which were lowered to 37％ in birds fed CPD diet and 70％ in PWV-fed birds and increased to two times in birds fed PFA . The contents of cholesterol in egg was not affected by experimental diets, while birds fed CPD diet increased significantly(P＜0.05) the daily biosynthesis of egg protein and showed a trend to increase the thickness of eggshell and eggshell contents per eggs compared with that of control diet-fed birds. The results indicated that the ground charcoal powder improved the performance of layer.

• Horticultural Science & Technology
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• v.17 no.3
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• pp.355-360
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• 1999

This study was carried out to investigate the effect of irrigation frequency, particle size and depth of perlite medium on the growth of Dendranthema grandiflorum (Ramat.) Kitamura 'Shuhouno-chikara' grown on recycling system. In Exp 1, the irrigation frequency (IF) was designed as 3 (IF3), 9 (IF9), and 18 (IF18) times a day. Fine and coarse particle size (PS) of perlite was used as a media, and depth of media (DM) was 15 and 10 cm contained in $34{\times}120{\times}15cm$ styrofoam bed. In Exp 2, the IF was 3 (IF3), 6 (IF6), and 9 (IF9) times a day with the same amount of nutrient solution. Fine and coarse PS were used, and DM was 15 and 7.5 cm. In this study, high IF and fine PS was favorable for plant growth. However, as the IF became frequent, difference of plant growth between fine and coarse PS became smaller. Also, shallow media showed little difference with deep media in plant growth. Thus, decreasing the amount of media was recommended to reduce the production cost.

• Journal of the Korean Crystal Growth and Crystal Technology
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• v.7 no.1
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• pp.108-116
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• 1997

A laboratory experiment was made of critical transition flow modes in Czocllralski convection. Numerical computation was also made to delineate the dynamic transition. The period of temperature oscillation ($t_p$) and the interval of temperature oscillation ($\Delta\theta$) were scrutinized to capture the critical transition regime. The mixed convection parameter was varied in the range of $0.134\le Ra/PrRe^2 \le3.804$. The data from calculation were in good agreement with ones from experiment. The influence of the Prandtl number on the transition was examined for Pr ＝ 910, 4445 and 8889. To understand the transition mechanism, the detailed temperature oscillation modes, the isolines of meridional temperature and the axial velocity profiles were investigated.

• Transactions of the Korean Society of Mechanical Engineers
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• v.19 no.3
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• pp.834-845
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• 1995

An experimental study is made in a nearly two-dimensional 90.deg. curved duct to investigate the effects of interaction between streamline curvature and mean strain on turbulence. The initial shear at the entrance to the curved duct is varied by an upstream shear generator to produce five different shear conditions ; a uniform flow (UF), a positive weak shear (PW), a positive strong shear(PS), a negative weak shear (NW) and a negative strong shear(NS). With the mean field data of the case UF, variations of the momentum thickness, the shape factor and the skin friction over the convex(inner) surface and the concave (outer) surface are scrutinized quantitatively in-depth. It is found that, while the pressure loss due to curvature is insensitive to the inlet shear rates, the distributions of wall static pressure along both convex and concave surfaces are much influenced by the inlet shear rates.

• Journal of the Korean Arthroscopy Society
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• v.16 no.2
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• pp.185-189
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• 2012

The objective of this case report was to evaluate meniscal suturing for a young patient with a chronic radial tear of the incomplete discoid lateral meniscus. The patient underwent saucerization in conjunction with repair of the displaced radial tear of the discoid meniscus. Six-months after surgery, arthroscopic examination showed the repaired meniscus to be healed well with good continuity. Repair of radial tears, even chronic tears, should be considered for young patients with torn discoid lateral menisci.

• Journal of the Korean Society of Propulsion Engineers
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• v.17 no.2
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• pp.105-113
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• 2013

A numerical model of the igniter for the interior ballistics has been developed by combining lumped parameter model with the theoretical equation of orifice. With the developed model of the igniter, the numerical study on characteristics of the interior ballistics has been conducted according to the igniter configuration in terms of igniter length, side hole diameter, and distribution of side holes. As results of the calculation of the pressure difference between the breech and shot base, the low-cycle oscillations have been influenced by the igniter length, while the high-cycle oscillations have been affected by the side hole diameter and the distribution of side holes.

• Transactions of Materials Processing
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• v.31 no.2
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• pp.57-63
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• 2022

The current study performed formability analysis of a heat exchanger separator for an electric vehicle to apply a high-strength aluminum sheet based on parametric analysis. Mechanical properties for sheet metal forming simulation were evaluated by tensile test, bulge test, and Nakajima test. Two-stage crash forming was established by considering the mass production process using conventional low-strength aluminum sheets. In this study, FEM for the two-stage forming process was conducted to optimize the corner radius and height for improving the formability. In addition, the possibility of a one-stage forming process application was confirmed through FEM. The prototype of the sample was manufactured as FEM results to validate the parametric analysis. Finally, this result can provide a one-stage forming process design method using the high-strength aluminum sheet for weight reduction of a heat exchanger separator for an electric vehicle.

• Journal of Chest Surgery
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• v.41 no.3
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• pp.320-328
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• 2008

Background: Numerous surgical devices for mitral repair have been used in the past with good results. In this study we describe a simple annuloplasty technique with using a new device ($Mitracon^{(R)}$). The aim of this study was to assess its efficacy and surgical results with using $Mitracon^{(R)}$. Material and Method: From May 2003 to October 2005, 46 patients (21 women and 25 men (mean age of $51.4{\pm}17.8$ years) with mitral regurgitation from various causes were treated with either the $Mitracon^{(R)}$ (the $Mitracon^{(R)}$ group) or the Capentier Edward rigid ring (the CE group). The median follow-up duration was 18.9 months. Result: The mean grade of mitral regurgitation before and immediately after surgery in the $Mitracon^{(R)}$ group and the CE group decreased from $3.2{\pm}0.8$ to $0.6{\pm}0.7$ and $3.4{\pm}0.7$ to $0.3{\pm}0.5$, respectively. There were no significant changes in the ejection fraction either between the two groups or before and immediately after surgery. No deaths were seen in either group. Early postoperative echocardiography of all 46 patients showed only trivial mitral regurgitation or none at all. Echocardiography at a median of 18.9 months also showed no progression in mitral regurgitation. The mean grade of mitral regurgitation in the $Mitracon^{(R)}$ group at this time point decreased from $3.2{\pm}0.8$ to $0.8{\pm}0.7$ (p<0.05). The CE group also showed a similar degree of decrease from $3.4{\pm}0.7$ to $0.3{\pm}0.6$ (p<0.05). The mitral valve area in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.3{\pm}0.9cm^2$. The mitral valve area in the CE group was $2.7{\pm}0.6cm^2$. The mean mitral pressure gradient in the $Mitracon^{(R)}$ group at 1 year follow-up was $3.1{\pm}1.3$ mmHg. The mean pressure gradient in the CE group was $4.5{\pm}2.1$ mmHg, although any statistical significant difference for this between the groups was not reached. Conclusion: The present study showed the described technique to be safe and effective in the intermediate term. Because long term results are unavailable, a more extensive prospective randomized multicenter trial may be warranted to determine whether this procedure should be generally applied for repair of mitral valve disease.