• Proceedings of the Korean Institute of Building Construction Conference
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• 2012.11a
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• pp.13-14
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• 2012

This study investigates the effect of adhesive type applying to surface-strengthening Ondol floor on level of attachment. Adhesive materials of four types produced in different companies were prepared and their attaching performance was examined. Test results showed that the water-based epoxy type produced in S company was the most effective on attaching the pieces of the surface-strengthening Ondol floor product.

• Journal of Korean Physical Therapy Science
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• v.9 no.2
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• pp.49-66
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• 2002

This study was designed to evaluate the effect of pelvic floor muscle strengthening exercise treatment program for the older women with stress incontinence. The researcher developed 8 weeks training program which was implemented at a social welfare center in Seoul. The exercise method followed the Kegel criteria. Verbal instructions were given to the subjects. Subjects were confirmed of the exercises and evaluated by description of the exercise method. Fourteen elderly women(mean age 75.7) with stress incontinence participated and completed this program. The training sessions were held twice a week and each session took 45 minutes ; 15 minutes for pelvic floor muscle strengthening program and 30 minutes for other physical therapy. Pelvic floor muscle strengthening exercise program was applied using verbal instruction and practice at social welfare center, twice a week and daily home exercise program were given to each individual. The results were as follows ; 1. There was significant decrease of lower urinary symptoms in the subjects (p = 0.00) 2 But there was no significant change in the sexual matters (p = 0.44) and the life style (p = 0.41) In conclusion, further study with larger sample group is suggested in order to confirm the study result. Because of limited sample size, the study results were not conclusive. But the pelvic floor muscle strengthening exercise treatment program could be a safe and effective program and is suggestive for the community residing older women with stress incontinence as a geriatric physical therapy intervention.

• Advances in concrete construction
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• v.9 no.4
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• pp.423-435
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• 2020

Open ground story (OGS) reinforced concrete (RC) buildings are vulnerable to the complete collapse or severe damages under seismic actions. This study investigates the effectiveness of four different strengthening techniques representing the local and global modifications to improve the seismic performance of a non-ductile RC OGS frame. Steel caging and concrete jacketing methods of column strengthening are considered as the local modification techniques, whereas steel bracing and RC shear wall systems are selected as the global strengthening techniques in this study. Performance-based plastic design (PBPD) approach relying on energy-balance concept has been adopted to determine the required design force demand on the strengthening elements. Nonlinear static and dynamic analyses are carried out on the numerical models of study frames to assess the effectiveness of selected strengthening techniques in improving the seismic performance of OGS frame.. Strengthening techniques based on steel braces and RC shear wall significantly reduced the peak interstory drift response of the OGS frame. However, the peak floor acceleration of these strengthened frames is amplified by more than 2.5 times as compared to that of unstrengthened frame. Steel caging technique of column strengthening resulted in a reasonable reduction in the peak interstory drift response without substantial amplification in peak floor acceleration of the OSG frame.

• Geomechanics and Engineering
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• v.20 no.1
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• pp.67-73
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• 2020

With the increasing number of underground projects, the problem of rock-water coupling catastrophe has increasingly become the focus of safety. Grouting reinforcement is gradually applied in subway, tunnel, bridge reinforcement, coal mine floor and other construction projects. At present, cement-based grouting materials are easy to shrink and have low strength after solidification. In order to overcome the special problems of high water pressure and high in-situ stress in deep part and improve the reinforcement effect. In view of the mining conditions of deep surrounding rock, a new type of cement-based reinforcement material was developed. We analyses the principle and main indexes of floor strengthening, and tests and optimizes the indexes and proportions of the two materials through laboratory tests. Then, observes and compares the microstructures of the optimized floor strengthening materials with those of the traditional strengthening materials through scanning electron microscopy. The test results show that 42.5 Portland cement-based grouting reinforcement material has the advantages of slight expansion, anti-dry-shrinkage, high compressive strength and high density when the water-cement ratio is 0.4, the content of bentonite is 4%, and the content of Nano Silica is 2.5%. The reinforcement effect is better than other traditional grouting reinforcement materials.

• Proceeding of KASS Symposium
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• 2008.05a
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• pp.61-65
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• 2008

A 4-story reinforced concrete structure built above an underground parking garage shows some slab deflections, and the deflections of the concrete floor slabs are proposed to be alleviated by the application of light-weight topping material in conjunction with localized strengthening of the slabs. The application of light-weight concrete topping on the existing slab has been simulated and its performance to anticipated loads has been analyzed. The application of light-weight topping material imposes additional weight on the exiting floor slabs. This added weight on the existing slabs causes over-stressing of the slabs. This over-stressing can be alleviated by enhancing the load carrying capacity of the existing slabs. Additional load carrying capacity in the existing slabs can be developed by localized strengthening of the slabs utilizing techniques such as the application of fiber-reinforced composites on the bottom surface of the slabs, and application of fiber-reinforced composites adequately complements the capacity of the existing slabs to bear the additional load imposed by light-weight leveling material. Additional moments in the beam and columns induced by the application of the light-weight topping material were tabulated and compared with capacity. The moment D/C ratios of the beam and columns are well the range of acceptable limits, and the beam and columns are not overstressed by the application of the surcharge.

• Proceedings of the Korean Society for Noise and Vibration Engineering Conference
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• 2006.05a
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• pp.1243-1246
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• 2006

As remodeling market is growing and peoples' concern on health and well-being is getting high, there is a need to apply environmentally friendly approach to remodeling an apartment houses. But, in point of the impact noise concerned, the thickness of the concrete slab and the limited ceiling height of the remodelling houses are the main constraints to improve the impact noise performance. In order to investigate the effect of the impact noise isolation as structural treatments for the structural elements, heavy-weight impact noise and tapping noise were measured in an remodeling building. As a result, structural strengthening method by H-beam was successful to enhance the impact noise level at about 3 or 4 class by the sound classification system.

• Journal of the Korea Institute of Building Construction
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• v.24 no.5
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• pp.529-540
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• 2024

This research aimed to refine the concrete floor finishing for enhancing its performance compared to the traditional way. The new method involved the removing the deteriorated mortar layer and reinforcing the surface to augment the durability and bond strength of the floor surface. This study performed the experience to evaluate the bond strength, drop depth, rebound hammer hardness, and the surface hardness of the surface by adopting traditional and refined method. The results showed the proposed method enhanced the performance on all the metrics. Based on the experiment, the bond strength increased about 2.79 times before installing the finishing material, and the strength also improved about 1.67 times and 1.44 times at the painted finishing and non-painted finishing, respectively. In addition, the drop depth decreased about 4.42 times when adopting the proposed method, which shows the enhanced resistance to declamination compared with applying the traditional way. Lastly, the surface hardness measured by scratch thickness significantly improved about 505% in this experiment. The finding of this study indicates that the proposed method can substantially enhance in bond strendth and durability of floor finishing, reduce the defects of the concrete-based floor, and extend the life of the products.

• Journal of Korean Academy of Nursing
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• v.45 no.5
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• pp.713-722
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• 2015

Purpose: The purpose of this study was to investigate the effects of pelvic floor muscle exercise using electric stimulation and biofeedback on maximum pressure of vaginal contraction, vaginal contraction duration and sexual function in women who have had vaginal rejuvenation. Methods: The research design was a non-equivalent control group non-synchronized design study. Participants in this study were women who had vaginal rejuvenation at C obstetrics and gynecology hospital. The 15 participants in the experimental group were given pelvic floor muscle exercise using electric stimulation and biofeedback and the 15 participants in the control group received self pelvic floor muscle exercise. Results: For maximum pressure of vaginal contraction, the experimental group showed a statistically significant increase compared to than the control group (t=5.96, p <.001). For vaginal contraction duration, the experimental group also showed a statistically significant increase compared to the control group (t=3.23, p =.003). For women' s sexual function, the experimental group showed a significant increase when compared to the control group in total sexual function scores (t=3.41, p =.002). Conclusion: The results indicate that pelvic floor muscle exercise with electric stimulation and biofeedback after vaginal rejuvenation is effective in strengthening vaginal contraction pressure, vaginal contraction and that it also positively functions to increase women's sexual function.

• Proceedings of the Korea Concrete Institute Conference
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• 2001.05a
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• pp.243-248
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• 2001

The objective of this study is to investigate the thermal conductivity of cement mortar for apartment housing floor using expansive admixture, copper fiber, cower lathe, hollowed aluminum plate. According to test results, temperature at point (a) located above heating pipe does not show significant variation with age, and temperature at (b), which is located at the finishing surface above heating pipe, and temperature at (c), which is located at center surface between heating pipe has remarkable change. Temperature distribution sat (b) are in order for, structure containing copper fiber>plain structure>structure containing hollowed aluminum plate>structure containing expansive admixture. Temperature distribution, shows high tendency in order for, structure containing copper fiber>structure containing copper lathe>structure containing hollowed aluminum plate>plain structure>structure containing expansive admixture. (a) estimation of temperature distribution is determined with the variation of temperature between (b) point and (c) point during 60 minutes heating.

• Proceedings of the Earthquake Engineering Society of Korea Conference
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• 2002.09a
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• pp.341-348
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• 2002

In these days, The base isolation system is often used to improve the seismic capacity of the structures instead of conventional techniques of strengthening the structural members. The purpose of this study is to evaluate dynamic property evaluation of control equipment using lead Lead Rubber Bearing. In this study, a base isolation test of seismic monitoring control cabinet with LRB(lead rubber bearing) was performed. The cabinet will be installed on access floor in MCR(main control room) of nuclear power plant. Details and dynamic characteristics of the access floor were considered in the construction of testing specimen. N-S component of El Centre earthquake was used as seismic input motion. Acceleration response spectrums in the top of cabinets showed that the first mode frequency of cabinet with LRB(lead rubber bearing) was shifted to 7.5 Hz in compared with 18Hz of cabinet without LRB and the maximum peak acceleration was reduced in a degree of22 percent from 2.35 g to 1.84 g