• Journal of the Korean Society of Safety
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• v.19 no.2
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• pp.93-97
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• 2004

Slab formwork consists of sheathing, stringer, hanger and shore. There are several types of adjustable individual shores. In constructions site, pipe supports are usually used as shores. The strength of a pipe support is decreasing as it is frequently being used at the construction site. In this study, 2857 pipe supports were bought to fine out the strength change of used pipe support and unused pipe supports according to aging. Among these pipe supports, 2337 pipe supports were lent to the construction companies free of charge. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports almost equaled to the strength of new pipe supports until 191 days, but the strength of used pipe supports at 191 days was lower than the strength of new pipe supports. So, the strength of used pipe supports at 191 days was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the paresent study results will be able to provide a firm base to design slab formwork and test the performance of used temporary structure and prevent formwork collapses.

• Journal of the Korean Ceramic Society
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• v.52 no.3
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• pp.180-185
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• 2015

Low-cost ceramic membrane supports with pore sizes in the range of $0.52-0.62{\mu}m$ were successfully prepared by uniaxial dry compaction method using inexpensive raw materials including kaolin, bentonite, talc, sodium borate, and alkaline-earth oxides in carbonate forms (e.g., $MgCO_3$, $CaCO_3$, and $SrCO_3$). The prepared green supports were sintered at $1000^{\circ}C$ for 8 hr in air. The effect of alkaline-earth oxide additives on the flexural strength of clay-based membrane supports was investigated. The porosity of the clay-based membrane supports was found to be in the range of 33-34%. The flexural strength of the clay-based membrane supports with 1% alkaline-earth carbonates was found to be in the range of 42.8-52.7 MPa. The addition of alkaline-earth carbonates to clay-based membrane supports resulted in large increases (47-80%) in the flexural strength of the membrane supports, compared to that of membrane supports without alkaline-earth carbonates. The typical flexural strength of the clay-based membrane support with 1% $SrCO_3$ was 52.7 MPa at 33.8% porosity.

• Journal of Agricultural Extension & Community Development
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• v.27 no.3
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• pp.145-158
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• 2020

Self-esteem and social supports are important variable influencing adjustment to college life. The study aims to identify the factors influencing college students' adjustment moderating effects on social supports. Data were collected from 265 usable questionnaires among college students in Pyeongtek University. Results of a factor analysis yielded three dimensions of self-esteem which were talent/attitude and capacity/pride. And results of factor analysis also yielded three dimensions of social supports which were family, friends, and professor supports. Hierarchical regression analysis revealed that capacity/pride and all of social support factors affected significantly for adjustment to college life. And female and attitude for students' major had a positive affect on adjustment to college life. It was suggested that self-esteem, social supports, and aptitude for students' major should be considered in college management policy.

• Structural Engineering and Mechanics
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• v.5 no.6
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• pp.691-703
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• 1997

This paper investigates the optimal locations of internal point supports in a symmetric crossply laminated rectangular plate for maximum fundamental frequency of vibration. The method used for solving this optimization problem involves the Rayleigh-Ritz method for the vibration analysis and the simplex method of Nelder and Mead for the iterative search of the optimum support locations. Being a continuum method, the Rayleigh-Ritz method allows easy handling of the changing point support locations during the optimization search. Rectangular plates of various boundary conditions, aspect ratios, composed of different numbers of layers, and with one, two and three internal point supports are analysed. The interesting results on the optimal locations of the point supports showed that (a) there are multiple solutions; (b) the locations are dependent on both the plate aspect ratios and the number of layers (c) the fundamental frequency may be raised significantly with appropriate positioning of the point supports.

• Journal of Family Resource Management and Policy Review
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• v.22 no.1
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• pp.79-98
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• 2018

The purpose of this study was to analyze the influence of a married adult on child-toparent and on parent-to-child financial supports. The data, derived from Korean General Social Survey(KGSS) was obtained from the Survey Research Center at Sung Kyun Kwan University. The samples included 367 married adult children who had more than one living parent. Multiple regression analysis was used to analyze the research model. The findings from the analysis showed that monthly household income had no significant impact on the financial supports that adult children provided to their parents or that the parents provided to their child. The expectation of financial supports from their parents in the future was a important factor that affected the level of female and male children's financial supports that they received from their parents. The level of instrumental supports from their parents and their parents-in-law did influence the level of financial transfers between them. These results showed that financial transfers between married adult children and their parents differed based on the children's attitude towards the supporting parents, and whether or not the children or parents had alternative resources available to them for financial supports. Moreover, the variation in financial supports and benefits showed complex differences based on the gender of the children, and based on whether the financial support was coming from the respondent's parents or their partner's parents.

• Bulletin of the Korean Chemical Society
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• v.31 no.2
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• pp.331-334
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• 2010

In the present study, carbon supports mixed with purified multi-walled carbon nanotubes (MWNTs) and carbon blacks (CBs) were used to improve the cell performance of direct methanol fuel cells (DMFCs). Additionally, the effect of $O_2$ plasma treatment on CBs/MWNTs supports was investigated for different plasma RF powers of 100, 200, and 300 W. The surface and structural properties of the CBs/MWNTs supports were characterized by FT-IR, X-ray photoelectron spectroscopy (XPS), X-ray diffraction (XRD), and inductive coupled plasma-mass spectrometer (ICP-MS). The electrocatalytic activity of PtRu/CBs/MWNTs catalysts was investigated by cyclic voltammetry measurement. In the experimental results, the oxygen functional groups of the supports were increased with increasing plasma RF power, while the average Pt particle size was decreased owing to the improvement of dispersibility of the catalysts. The electrochemical activity of the catalysts for methanol oxidation was gradually improved by the larger available active surface area, itself due to the introduction of oxygen functional groups. Consequently, it was found that $O_2$ plasma treatments could influence the surface properties of the carbon supports, resulting in enhanced electrocatalytic activity of the catalysts for DMFCs.

• Computers and Concrete
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• v.28 no.6
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• pp.559-566
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• 2021

In this paper, frequency analysis has been done for functionally graded cylindrical shell with ring supports using Sander's shell theory. The vibrations of rotating cylindrical shells are analyzed for different physical factors. The fundamental natural frequency is investigated for different parameters such as: ratios of length-to-diameter ring supports. By increasing different value of height-to-radius ratio, the resulting backward and forward frequencies increase and frequencies decrease on increasing height-to-radius ratio. The frequencies for different position of ring supports are obtained in the form of bell shaped. The backward frequencies increases and forward frequencies decrease on increasing the rotating speed. The results generated furnish the evidence regarding applicability of present shell model and also verified by earlier published literature.

• Journal of the Korean Society of Safety
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• v.21 no.3 s.75
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• pp.101-106
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• 2006

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. Among the accidents and failures that occur during concrete construction, there are many formwork failures which usually happen at the time concrete is being placed. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies free of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. In this study, the strength of pipe support according to age, use frequency and load carrier was predicted using SPSS 12.0. It was known that the strength of pipe support using for 5 years was reduced to 42.8%. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a finn base to prevent formwork collapses.

• Journal of the Korean Society of Safety
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• v.20 no.3 s.71
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• pp.120-125
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• 2005

Formwork is a temporary structure that supports its weight and that of freshly placed concrete as well as construction live loads. Among the accidents and failures that occur during concrete construction, many are formwork failures which usually happen at the time concrete is being placed. In constructions site, pipe supports are usually used as shores which are consisted of the slab formwork. The strength of a pipe support is decreasing as it is frequently being used at the construction site. The objective of this study is to find out the strength change of used pipe support and unused pipe supports according to aging. In this study, 2857 pipe supports were prepared. Among these pipe supports, 2337 pipe supports were lent to the construction companies fire of charge. 520 pipe supports were kept on the outside. Compressive strength was measured by knife edge test and plate test at each 3 month. Test results show that the strength of unused pipe supports as well as used pipe supports was decreasing according to age, use frequency and load carrier, and the strength of used pipe supports was lower than the strength of unused pipe supports at the same age. So, the strength of used pipe supports from 191 days to present day was not satisfied the specification of KS F 8001. According to these results, it shows that attention has to be paid to formwork design using used pipe supports. Therefore, the present study results will be able to provide a firm base to prevent formwork collapses.

• Structural Engineering and Mechanics
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• v.2 no.4
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• pp.369-381
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• 1994

This paper is concerned with the elastic buckling of cylindrical shells with internal rigid ring supports. The internal supports impose a zero lateral deflection constraint on the buckling modes at their locations. An automated Rayleigh-Ritz method is presented for solving this buckling problem. The method can handle any combination of end conditions and any number of internal supports. Moreover, it is simple to code and can yield very accurate solutions. New buckling results for cylindrical shells with a single internal ring support, and under lateral pressure and hydrostatic pressure, are given in the form of design charts. These results should be valuable to engineering designers.