• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.5C
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• pp.283-292
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• 2008

In this research, finite difference (FD) scheme for the interface of the layer between different soil characteristics was suggested. Based on the suggested scheme, FD analysis program for the consolidation analysis of the multi-layered and smeared soil was developed. And the applicability of the program was investigated by the FD analysis conducted for the various soil conditions. Analysis results showed that the permeability near the drainage boundary had a dominant effect on the consolidation rate. And the consolidation rate of the soil with the constant permeability in smeared area was retarded more than the soil with the linear variation of permeability in smeared area. Simple assumption of the constant variation of permeability in smeared area could be used when the decreasing rate of permeability in smeared area was relatively low. But exact assumption of the permeability variation in smeared area should be considered when the decreasing rate of permeability in smeared area was relatively high. Finally, based on the analysis result on Busan area, the analysis considering multi-layered soil should be needed to exactly evaluate time for the completion of consolidation.

• KSCE Journal of Civil and Environmental Engineering Research
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• v.28 no.3D
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• pp.363-369
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• 2008

Change is inevitable and is a reality of construction projects. Change adjustment includes the cost associated with materials, labor, etc. However, the actions of a contractor can cause a loss of productivity and furthermore can result in disruption of the whole project because of a cumulative or ripple effect. Because of its complicated nature, it becomes a complex issue to determine the cumulative impact (ripple effect) caused by single or multiple change orders. Furthermore, owners and contractors do not always agree on the adjusted contract price for the cumulative impact of the changes. What is needed is a reliable method to identify and quantify the loss of productivity caused by cumulative impact of change orders. This study survey the change orders data in domestic area for public construction and analyze to quantify change order impact. This study developed concepts of "%CO", "%Delta", "%T" to capture change order effect on project and search the relationships between them. Finally, this study find strong relationship between change order and loss.

• Journal of Industrial Convergence
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• v.19 no.4
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• pp.65-74
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• 2021

The purpose of this study was to investigate the effect of bicarbonate intake on blood variables during high-intensity training of sprinters. 30 male/female elites with more than 3 years of experience that are registered to S city as a sprinter was categorized into three groups: control group, training group, and HCO₃^- and training group. Training group and HCO₃^- and training group went through a high-intensity exercise program (80-90% HR max) which escalated every 2-3 weeks, for 90 minutes at a time, 5 days a week, 8 weeks in total. HCO₃^- and Training group took in 300mg of bicarbonate per one kilogram of body weight, in 90 minutes before the start of the high-intensity exercise program, once a day for 8 weeks. As a result of the study, the effect of bicarbonate intake on blood variables during high-intensity training of sprinters showed a positive effect on the increase of pH and the decrease of lactic acid in HCO₃^- and training group. Also, the increase of Ca²⁺, Na⁺, K⁺ was shown in training group and HCO₃^- and training group, whereas there were no indications of significant change in Mg²⁺ in all three groups. It can be confirmed that the intake of bicarbonate during high-intensity training shows effective changes in the increase of pH and the decrease in lactic acid among changes in blood variables. Therefore, it can be seen that the intake of bicarbonate during high-intensity exercise is effective in improving exercise capacity.

• Journal of Industrial Convergence
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• v.21 no.7
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• pp.51-63
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• 2023

This study aimed to verify the effects of a 4-week program of ankle-strengthening exercise and toe-taping walk exercise on the basic lower body strength and walking to examine the benefits of the two exercises. The subjects involved 30 women in their 20s enrolled in university A. The subjects were equally divided into three groups - ankle-strengthening exercise group, toe-taping walk exercise group, and control group. The subjects were instructed to massage and do ankle-strengthening exercises using a towel, massage ball, and CRT, for 60 minutes, 3 times a week. They also taped their hallux valgus using a kinesiology tape and walked for 20 minutes with white tape applied. To sum up, the 4-week ankle-strengthening exercise and toe-taping walk exercise were identified to have a partial statistical significance on the basic lower body strength (muscular strength, power, and balance) and walking (length of gait line, plantar pressure, and COP) of women in their 20s. Therefore, the study confirmed the effects of ankle-strengthening exercises and toe-taping walk exercise on the lower body exercise function, and it is considered that further studies should be conducted on more various effects of the exercises by subdividing them into different pain locations and orthomechanic findings.