• Proceedings of the Korea Concrete Institute Conference
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• 1994.10a
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• pp.127-132
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• 1994

This study attemps to investigate the influence of heat of hydration occured during hardening on the strength development of high strength concrete. The concrete design strengths of 500kg/$\textrm{cm}^2$ and 700kg/$\textrm{cm}^2$ were considered to simulated the square columns having $80\times80cm$ and $100\times100cm$, respectively. Both standard curing and field curing specimen were prepared at the specified ages, and the cores were drilled out from the structure. The thermal sensors were installed into the specimen to measure the heat of hydration process occurred during the hardening. This paper tries to uncover the relationship between the temperature history of the concrete and strength development. The correlation of core strength and specimen strength with curing condition is also discussed. Further research is desired to enlight the relationship between strength and heat of hydration of high strength concrete.

• Journal of Distribution Research
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• v.15 no.1
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• pp.73-101
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• 2010

Using data collected from franchisees from Busan, we empirically examined the relationship both structural (tie strength), relational (trust), and cognitive (shared value) of social capital and between those dimensions and the patterns of economic performance and noneconomic performance (relationship continuity intention). So we established 9 hypotheses to test the structural relationship among dimensions of social capital and performances like below. H1: A franchisee's perceived tie strength with its franchisor will positively influence its trust in the franchisor. H2: A franchisee's perceived shared value with its franchisor will positively influence its trust in the franchisor. H3: A franchisee's perceived tie strength with its franchisor will positively influence its economic performance. H4: A franchisee's perceived shared value with its franchisor will positively influence its economic performance. H5: A franchisee's perceived trust in its franchisor will positively influence its economic performance. H6: A franchisee's perceived tie strength with its franchisor will positively influence its relationship continuity intention with the franchisor. H7: A franchisee's perceived shared value with its franchisor will positively influence its relationship continuity intention with the franchisor. H8: A franchisee's perceived trust in its franchisor will positively influence its relationship continuity intention with the franchisor. H9: A franchisee's perceived economic performance will positively influence its relationship continuity intention with the franchisor. The conceptual model specifying the relationship among dimensions of social capital and performances is presented in Fig. 1. Tests of the hypotheses were performed using a structural equation model. This model also reflected a good fit to the data ($\chi^2$=101.12 df=62 p=0.004, RMSEA=0.050 GFI=0.936 AGFI=0.895 NFI=0.959 CFI=0.986). The standardized solution estimated by the AMOS 7 program was for interpreting the structural results (Table 1). As was expected, tie strength and shared value were founded to be significant predictors of trust (H1 supported; H2 supported). Tie strength and trust have a significant positive effect on economic performance (H3 supported; H5 supported). But shared value have not a significant effect on economic performance (H4 Rejected). Tie strength were not associated with relationship continuity intention (H6 Rejected). While on the other higher shared value, trust, and economic performance have a significant effect on the relationship continuity intention (H7 supported; H8 supported; H9 supported). The results show integratedly that, first, tie strength does not affect directly but affects indirectly on relationship continuity intention via trust and economic performance. Second, shared goals affect directly and do indirectly via trust on relationship continuity intention. But shared goals does not affect via economic performance on relationship continuity intention. Finally, the study suggests important implications for both research and practice for franchise system especially.

• Journal of the Korea Concrete Institute
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• v.22 no.4
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• pp.481-488
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• 2010

Since existing constitutive models developed for confined normal strength concrete overestimate ductility when they are applied to confined high strength concrete, these models cannot be directly applied to confined high strength concrete. In an effort to solve this problem, an accurate stress-strain relationship of the hihg strength concrete needs to be formulated by examining the confinement effects due to increase of the concrete strength. In this study, a constitutive model is developed to express the stress-strain relationship of confined high strength concrete by carrying out regression analysis of the main parameters affection strength and ductile behavior of reinforced high strength concrete columns. Twenty-five test specimens were chosen from the reported experimental studies in the literature. The experimental results of stress-strain relationships of show a good agreement with results of the stress-strain relationships of suggested high strength concrete, covering a strength range between 60 and 124 MPa.

• Proceedings of the Korean Geotechical Society Conference
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• 2006.03a
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• pp.402-413
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• 2006

Strength evaluation of soft soils is a formidable task because of difficulties in sampling, specimen preparation and setting in triaxial cells. In undrained triaxial testing, sampling disturbance, verticality of specimen and bedding effect give a great influence on shear strength measurements. In the other hand, shear wave measurements of specimens are less influenced by these factors. In this research, the bender elements were attached top cap and base pedestal of triaxial cell and shear wave velocities were measured. To initiate a methodology to evaluate shear strength indirectly by measuring shear wave velocity, a relationship between shear strength and shear wave velocity was developed with kaolinite specimens consolidated in the laboratory. Undrained shear strength turns out to increase linearly with shear wave velocity. Stress-strain curves can also be predicted with a hyperbolic model and shear wave measurements.

• Journal of the Korea Furniture Society
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• v.12 no.1
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• pp.21-26
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• 2001

This study was carried out to get some basic information on mechanical properties of Platanus orientalis L. for the rational utilization of this wood. Relationship of anatomical characteristics with compression strength parallel to grain was analyzed using stepwise regression technique. All possible combination of 8 independent variables were regressed on compression strength parallel to grain. The summarized results in this study were as follows: 1. The compression strength parallel to grain increased with the increase of wood fiber length and wood fiber width. The strength, however, decreased with increase of number of pore per $\textrm{mm}^2$ and tangential diameter of pore. 2. The major factors affecting compression strength parallel to grain in heartwood were length of wood fiber and number of pore $per{\;}{\textrm{mm}^2}$ but width of wood fiber and length of vessel element were the important factors in sapwood.

• Journal of the Korea Concrete Institute
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• v.11 no.4
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• pp.137-145
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• 1999

The use of steel fiber reinforced to improve the strength and flexural toughness of concrete is well known, but reinforcement of polymer concrete with steel fibers has been hardly reported till now. Polymer concrete has high strength, durability and freeze-thaw resistance than that of cement concrete, but it has disadvantage such as low flexural toughness. In this paper, the strength characteristics and flexural toughness of steel fiber reinforced polymer concrete are investigated experimentally with various steel fiber aspect ratios($\ell$/d), and contents(vol.%). As the result, the flexural and splitting tensile strengths and flexural toughness were increased aspect ratio, and reach the maximums at a aspect ratio of 50. The relationship between the compressive, flexural and splitting tensile strength were high. And the relationship between flexural strength and strain energy was approximately linear.

• Nutritional Sciences
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• v.4 no.2
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• pp.112-119
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• 2001

This study was performed fir the purpose of finding the relationship between fat-free mass (FFM) which mainly represents muscle mass change, and muscle strength. The correlation between diet and exercise behaviors and FFM in healthy elderly men over age 55 was also investigated. FFM and corresponding hand grip strength declined significantly with increasing age. However the concentration of serum albumin, the indicator of protein nutritional status, showed no change with increases in age. The subjects were categorized into three groups according to FFM textiles. Anthropometry such as height, BMI, circumferences of waist and hips, body fat mass percent and hand grip strength decreased significantly in the lowest FFM group. But albumin level showed no change relative to FFM level. FFM showed a significant relationship to nutrient intake such as energy and fat. However, no association was found with exercise behavior probably because there were no instances of resistance exercise habits among the subjects studied. The variance in FFM could be attributed 86.2% to height and age. The variance of height-adjusted FFM could be attributed only 40.6% to age and fat intake. In conclusion decreases in FFM may cause reductions in muscle strength in elderly men. Increasing energy and fat intake were associated with increased FFM and may protect elderly men from the risk of sarcopenia. FFM had no association with endurance exercise habits.

• Journal of Nutrition and Health
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• v.34 no.4
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• pp.449-457
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• 2001

This study was performed to show change of fat-free mass(FFM), representing mostly the muscle mass change, and muscle strength with increasing age, and relationship between dietary, exercise behaviors and FFM in healthy middle-and old aged women who are of age over 55 years. The FFM and correspondingly hand grip strength showed significant positive correlation with age. But concentration of serum albumin showed no significant relationship with age. The subjects were categorized into groups according to FFM tertile. The anthropometry such as weight, BMI, fat mass, circumferences of waist and hip, WHR, and hand grip strength decreased significantly in the lowest FFM group. But the albumin level showed no change according to FFM level. The FFM showed significant correlation with nutrient intakes such as energy, carbohydrate, protein, Fe, P, Ca. No association, however, was shown with exercise behavior probably because of no case with resistance exercise habits. The variance of FFM was explained 55.2% by height and carbohydrate intake. The variance of height-adjusted FFM could be explained only 16.2% by intake amount of carbohydrate. In conclusion, the decrease of FFM may cause to reduce muscle strength in female elderly. The increasing nutrient intakes were associated with the increased FFM and may protect from risk of sarcopenia. However, only the carbohydrate intake could influence independently the FFM in middle- and old-aged women. The FFM has no association with endurance exercise habits. (Korean J Nutrition 34(4) : 449∼457, 2001)

• Korean Journal of Child Studies
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• v.36 no.4
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• pp.111-127
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• 2015

This study was conducted in order to model the relationship between children's ego strength and their school adjustment and life satisfaction levels. For this purpose, 4,765 4th-6th grade elementary school children were surveyed by means of a questionnaire. The collected data were analyzed by means of structural equation modeling. The results of this study may be summarized as follows. First, in all the grades, a significant and positive correlation was observed between the children's ego strength and their school adjustment and life satisfaction levels. Second, ego strength was found to be a variable that had a significant effect on life satisfaction indirectly through the medium of school adjustment. Third, the relation model between the variables differed according to grade. That is, the direct effect of ego strength on life satisfaction was stronger in the high grades, and the level of school relationship adjustment was found to have a significant effect on family relationship satisfaction as a factor of life satisfaction in 4th graders, whereas it did not in the case of 5th and 6th graders.

• Journal of the Korean Society of Hazard Mitigation
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• v.10 no.2
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• pp.39-46
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• 2010

Concrete strength relationship between various strength properties was presented through experimental data from concretes made from different sources of coarse aggregates and fine aggregates, and different amount of cement contents. In the strength relationship were included compression-flexure, compression-split tension, compression-modulus and flexure-split tension. A total of 61~81 data sets were analyzed while each data set is composed of 3 to 4 experimental test data. Using the proposed strength relations, a procedure to reliably estimate modulus values from the LTPP field test section was suggested. Core specimens were taken from 10 LTPP sections on the expressway as well as 4 sections on the national road. Then compressive strengths and modulus were determined in the lab. Finally concrete modulus was averaged with the estimated values by using the derived relationship and experimental values.