• Journal of the Korea Institute of Building Construction
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• v.18 no.1
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• pp.41-49
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• 2018

The purpose of this study is to develop a floor mortar construction technique which has high strength and inherent mechanical properties and does not cause cracks due to shrinkage after construction. It has been demonstrated that compressive strength, bending strength, flow with floor mortar, and crack reduction performance. As a result, it was confirmed that the developed floor mortar had the same or better performance comparing with the existing foreign products. The results of this experiment can be used as a validation material for high performance and high flowable mortar construction technology with excellent material performance, economical efficiency and construction ability by securing the required performance as floor mortar and selecting the optimal formulation.

• PNF and Movement
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• v.20 no.1
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• pp.91-101
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• 2022

Purpose: The purpose of this study was to examine the effect of cycle ergometer exercise inducing movement of the affected side on knee joint function after total knee arthroplasty (TKA). Methods: The primary experiment was conducted on 19 members of the cycle ergometer exercise group to measure the muscle activity of the rectus femoris, hamstring, tibialis anterior, and gastrocnemius muscles during cycle ergometer exercise that induced the affected side's movement. In the second experiment, after receiving physiotherapeutic intervention for 30 min, the general bicycle exercise group and cycle ergometer exercise group performed the corresponding exercise for 15 min, 5 times per week, for 2 weeks. The ROM, muscle strength, pain, and balance were then measured and compared between the two groups. Results: In the results of the primary experiment, cycle ergometer exercise inducing movement of the affected side showed a significantly larger increase in the activity of leg muscles (rectusfemoris, hamstring, tibialis anterior, gastrocnemius) on the affected side than the general bicycle exercise (p <0.05). In the second experiment, the cycle ergometer exercise group showed a significantly larger increase in range of movement of affected side knee flexion and muscle strength of affected side knee flexion, knee extension, and plantarflexion than the general bicycle exercise (p <0.05). No significant between-group difference was observed in pain and balance before or after the intervention (p >0.05). Conclusion: Cycle ergometer exercise inducing movement of the affected side increases use of the muscles around the affected side knee joint after TKA more than general bicycle exercise and produces better effects for enhancing muscle strength. The application of cycle ergometer exercise inducing movement of the affected side is expected to reduce the patients' unbalanced use during the early postoperative period and help them to quickly return to normal daily life through rapid muscle strength recovery.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2008.11a
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• pp.93-96
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• 2008

This research performed strength improvement analysis after evaluating strength characteristics by estimated temperatures to evaluate the real time strength performance of 50 to 80 MPa high performance concrete equipped with heat resistance, and the results are as follows. The lesser W/B and the lesser target slump flow value difference, compression strength was shown to increase, and the more curing temperature becomes, the strength increased accordingly. According to the correlation review result of strength improvement analysis by estimated temperature change performed using logistic analysis model, the compression strength value predicted with logistic curve expression and the compression strength value measured in experiment were shown to have similar correlation, and the strength improvement analysis value by logistic model was shown to be estimated good when W/B is high.

• Proceedings of the Korea Concrete Institute Conference
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• 1997.04a
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• pp.323-328
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• 1997

The strength of concrete depends on factors of materials, composition and manufacturing method. Among these factors, preparatory experiments are to consider and analyze the factors on compressive strength of ultra-high strength concrete according to types of aggregate, binder content, water-binder ratio, and curing methods. And the final experiment to develop the ultra-high strength over 3,000kgf/$\textrm{cm}^2$ is based on these preparatory experiments. As the result of this final expriment. We could manufacture the ultra-high strength concrete with a marvelous compressive strength concrete with a marvelous compressive strength of 3,116kgf/$\textrm{cm}^2$. This study is to compare and analyze the manufacturing system of ultra-high strength concrete of 3,116kgf/$\textrm{cm}^2$ compressive strength in the side of material development of construction industry.

• Magazine of the Korean Society of Agricultural Engineers
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• v.43 no.6
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• pp.135-142
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• 2001

Laboratory experiment was performed to evaluate the influence of mixing conditions to the strength of solidified sandy soils with cement. The major physical factors considered in this experiment were the fine particles content(<$\sharp200%$), cement content(%) and water-cement ratio, and unconfined compressive strength test was performed on the samples at 7 and 28 cured day. The results of tests shows that when the cement content is relatively low (7~10 percents) the fine content in the sandy soils is very important, but when cement content is high the water-cement ratio became more important. It was appeared that in the range of the cement content of 7~10 percents, about 20~30 percents of fine content to the total sample weight is the optimum condition to get the maximum strength. In the case of the cement content of 13 percents, the strength of sample was considerably affected by the water-cement ratio rather than the fine content. In this paper, empirical equations were also developed and evaluated to verify the relationship among three factors by the multi-regression analysis.

• Journal of the Korea institute for structural maintenance and inspection
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• v.18 no.2
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• pp.90-98
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• 2014

The shear behavior of reinforced concrete structure is one of difficult problems that are not clearly identified theoretically despite the efforts of researchers for several years. Since bending and shear strength of hollow slab may decrease due to hollow part inside slab, prediction of such structure performance is very important. Presently the formulas of shear designing standard expressions of each country are formulas by experiment for hollow slab. In this study, the shear behavior of one-way hollow slab by reinforcement ratio were analyzed through experiment to conduct studying on estimation of shear strength, and then shear strength formulas of hollow slab were compared and analyzed.

• The Journal of Korean Physical Therapy
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• v.33 no.5
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• pp.224-230
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• 2021

Purpose: The purpose of this study was to investigate the effects of the fascia distortion model (FDM), one of the fascia treatments, on unstable ankle subjects. This was done through the chronic ankle instability tool (CAIT) questionnaire on maximum isometric muscle strength, proprioception, dynamic balance, and maximum angle. Methods: An experiment was conducted using the chronic ankle instability tool questionnaire on males and females in their twenties who suffered from ankle instability. Before the experiment, maximum isometric strength, proprioceptive, dynamic balance, and maximum angle were measured. The fascia distortion model was applied and then measurements were taken again to compare and analyze the changes. Analysis was carried out using the paired t-test. Results: After applying the fascia distortion model, maximum isometric strength, proprioceptive, dynamic balance, and maximum angle significantly improved (p<0.05). Conclusion: This study found that the fascia distortion model method was effective in improving maximum isometric strength, proprioceptive, dynamic balance, and maximum angle. The results suggest that the fascia distortion model method is a new intervention that could be used for subjects with chronic ankle instability.

• Proceedings of the Korean Institute of Building Construction Conference
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• 2021.05a
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• pp.57-58
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• 2021

This study is conducted an experiment to unifyprovide a method to estimate the method of measuring the condensationsetting time and estimating the initialearly age compressive strength using the existingD type ddurometer. into a single device and to adopt the best estimation guidelines of the estimator. As a result of the experiment, Test results indicated that it is analyzed that the use of D type Durometer attached with modified needle, which was designed to secure improved accuracy in setting and compressive strength, enables to estimate it is possible to estimate the condensationsetting time of mortar and estimate the compressive strength ofat early age. the initial age when the estimation No. 2 is adopted for the Durometer D type.

• Proceedings of the Korea Concrete Institute Conference
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• 1999.10a
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• pp.241-244
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• 1999

This study is represented the strength and freeing-thawing properties of recycled aggregate concrete mixed fly ash by experiment. The experimental variables are the substitution ratio of recycled aggregate and the mixing ratio of fly-ash. For each specimens, there were tested compressive strength and freeze-thaw resistance. It is able to find from the experimental result that the recycled aggregate concrete has good properties as general concrete on the compressive strength and the durability.

• Proceedings of the Korea Concrete Institute Conference
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• 1995.04a
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• pp.124-129
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• 1995

In this study proposed to rapid and simple methid of test for early evaluation of strength of cement. The obtained results through a series of experiment are summarized as follow. The resistance ratio was decreased as the increase of water-cement ratio. The compressive strength of cement was increased as the resistance ratio increase. The experimental results of compressive strength of cement is shown in the same value no relation with the kind of cement respectively.