• Journal of Periodontal and Implant Science
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• v.53 no.4
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• pp.295-305
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• 2023

Purpose: Various methods have been proposed to achieve the nearly complete decontamination of the surface of implants affected by peri-implantitis. We investigated the in vitro debridement efficiency of multiple decontamination methods (Gracey curettes [GC], glycine air-polishing [G-Air], erythritol air-polishing [E-Air] and titanium brushes [TiB]) using a novel spectrophotometric ink-model in 3 different bone defect settings (30°, 60°, and 90°). Methods: Forty-five dental implants were stained with indelible ink and mounted in resin models, which simulated standardised peri-implantitis defects with different bone defect angulations (30°, 60°, and 90°). After each run of instrumentation, the implants were removed from the resin model, and the ink was dissolved in ethanol (97%). A spectrophotometric analysis was performed to detect colour remnants in order to measure the cumulative uncleaned surface area of the implants. Scanning electron microscopy images were taken to assess micromorphological surface changes. Results: Generally, the 60° bone defects were the easiest to debride, and the 30° defects were the most difficult (ink absorption peak: 0.26±0.04 for 60° defects; 0.32±0.06 for 30° defects; 0.27±0.04 for 90° defects). The most effective debridement method was TiB, independently of the bone defect type (TiB vs. GC: P<0.0001; TiB vs. G-Air: P=0.0017; TiB vs. GE-Air: P=0.0007). GE-Air appeared to be the least efficient method for biofilm debridement. Conclusions: T-brushes seem to be a promising decontamination method compared to the other techniques, whereas G-Air was less aggressive on the implant surface. The use of a spectrophotometric model was shown to be a novel but promising assessment method for in vitro ink studies.

• Advances in concrete construction
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• v.13 no.2
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• pp.199-213
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• 2022

Experimental and discrete element approaches were used to examine the effects of F shape non-persistent joints on the failure behaviour of concrete under uniaxial compressive test. concrete specimens with dimensions of 200 cm×200 cm×50 cm were provided. Within the specimen, F shape non-persistent joint consisting three joints were provided. The large joint length was 6 cm, and the length of two small joints were 2 cm. Vertical distance between two small joints change from 1.5 cm to 4.5 cm with increment of 1.5 cm. In constant joint lengths, the angle of large joint change from 0° to 90° with increments of 30°. Totally 12 different models were tested under compression test. The axial load rate on the model was 0.05 mm/min. Concurrent with experimental tests, numerical simulation (Particle flow code in two dimension) were performed on the models containing F shape non-persistent joint. Distance between small joints and joint angles were similar to experimental one. the results indicated that the failure process was mostly governed by both of the Distance between small joints and joint angles. The axial loading rate on the model was 0.05 mm/min. The compressive strengths of the samples were related to the fracture pattern and failure mechanism of the discontinuities. Furthermore, it was shown that the compressive behaviour of discontinuities is related to the number of the induced tensile cracks which are increased by increasing the joint angle. In the first, there were only a few acoustic emission (AE) hits in the initial stage of loading, and then AE hits rapidly grow before the applied stress reached its peak. Furthermore, a large number of AE hits accompanied every stress drop. Finally, the failure pattern and failure strength are similar in both approaches i.e., the experimental testing and the numerical simulation approaches.

• Proceedings of the Korea Water Resources Association Conference
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• 2020.06a
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• pp.325-325
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• 2020

Low impact development (LID) is a widely used technology that aims to reduce the peak flow volume and amount of pollutants in stormwater runoff while introducing physicochemical, biological or a combination of both mechanisms in order to improve water quality. This research aimed to determine the effect of hydrologic factors in removing the pollutants on stormwater runoff by an LID facility. Monitored storm events from 2010-2018 were analysed to evaluate the hydraulic and hydrological performance of a small constructed wetland (SCW). Standard methods for the examination water and wastewater were employed to assess the water quality of the collected samples (APHA et al, 1992). Primary hydrologic data were obtained from the Korea Meteorological Administration. The recorded average rainfall intensity and antecedent dry days (ADD) of SCW were 5.26 mm/hr and 7 days respectively. During the highest rainfall event (27 mm/hr), the removal efficiency of SCW for all the pollutants was ranging from 67% to 91%. While on the lowest rainfall event (0.7 mm/hr), the removal efficiency was ranging from -36% to 62%. Rainfall intensity has a significant effect to the removal efficiencies of each facility due to its dilution factor. In addition to that, there was no significant correlation of ADD to the mean concentrations of pollutants. Generally, stormwater runoff contains significant amount of pollutants that can cause harmful effects to the environment if not treated. Also, the component of this LID facility such as pre-treatment zone, media filters and vegetation contributed to the effectivity of the LID facilities in reducing the amounts of pollutants present in stormwater runof.

• Physical Therapy Korea
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• v.30 no.3
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• pp.202-210
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• 2023

Background: The elderly population is increasing rapidly worldwide. Muscle mass, usual walking speed (UWS), knee extension strength (KES), hand grip strength (HGS), peak expiratory flow (PEF), and depression is used for sarcopenia diagnosis. All four of these factors (KES, HGS, PEF, and depression) correlated with UWS and also to muscle mass. But, many studies have suggested that no correlation exists between muscle mass and UWS. Objects: This study aimed: 1) to investigate whether muscle mass reduction affected UWS, as mediated by KES, HGS, PEF and depression, and 2) to explored whether significant changes in these mediators varied by the body segment in which muscle mass evaluated in elderly female aged 65-80 years. Methods: A total of 100 female aged 65-80 years were surveyed. Muscle mass was measured by body segment (upper and lower segment), and KES, HGS, PEF, depression, and UWS were also assessed. Median analyses were progressed in IBM SPSS software (ver. 23.0, IBM Co.) using a downloaded INDIRECT macro. Results: The direct effect of the KES and PEF were significant, and the indirect effect of KES and PEF were not significant. Thus, KES and PEF served as full mediators of the effect of muscle mass on UWS. Regardless of bodily region, KES and PEF combined with muscle mass were significant mediators of UWS, with similar indirect effect sizes. Conclusion: KES and PEF are the only mediators regardless of body part. Therefore, mediating the KES and PEF may prevent sarcopenia progression in elderly female. Also, sarcopenia can be readily assessed by evaluating either the upper or lower body; it is not necessary to measure total muscle mass.

• Journal of the Korean Society of Physical Medicine
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• v.17 no.2
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• pp.75-82
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• 2022

PURPOSE: This study examined the correlation between the pulmonary function and respiratory muscle strengthening training on an unstable support surface and a stable support surface in stroke patients. METHODS: The study subjects were 22 stroke patients undergoing central nervous system developmental rehabilitation treatment. After excluding six dropouts, eight people in the experimental group and eight people in the control groups were classified by random sampling. Both groups performed central nervous system developmental rehabilitation therapy and were provided a 10-minute break. The experimental group was provided with an unstable support surface using Togu, and the control group was trained to strengthen the respiratory muscle in a stable support surface. Respiratory muscle strengthening training was conducted three times per week for 20 minutes. Before and after each group of experiments, a nonparametric test Wilcoxon signed rank test, and a Mann Whitney U-test analysis were used to analyze the variations between the two groups. All statistical significance levels (α) were set at 0.05. RESULTS: Both groups showed increases in the pulmonary function but showed significant differences only in the experimental group. There was a significant difference in the peak expiratory flow between the two groups. CONCLUSION: Central nervous system development rehabilitation treatment for patients with an impaired nervous system and respiratory muscle strengthening training on unstable support surfaces are effective in improving the pulmonary function of stroke patients. Therefore, they are expected to be applied to physical therapy programs to help various functional activities.

• Smart Structures and Systems
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• v.32 no.5
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• pp.281-295
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• 2023

The purpose of this study is to demonstrate and verify the application of phase-control absolute-acceleration-feedback active tuned mass dampers (PCA-ATMD) to multiple-degree-of-freedom (MDOF) building structures. In addition, servo speed control technique has been developed as a replacement for force control in order to mitigate the negative effects caused by friction and inertia. The essence of the proposed PCA-ATMD is to achieve a 90° phase lag for a structure by implementing the desired control force so that the PCA-ATMD can receive the maximum power flow with which to effectively mitigate the structural vibration. An MDOF building structure with a PCA-ATMD and a real-time filter forming a complete system is modeled using a state-space representation and is presented in detail. The feedback measurement for the phase control algorithm of the MDOF structure is compact, with only the absolute acceleration of one structural floor and ATMD's velocity relative to the structure required. A discrete-time direct output-feedback optimization method is introduced to the PCA-ATMD to ensure that the control system is optimized and stable. Numerical simulation and shaking table experiments are conducted on a three-story steel shear building structure to verify the performance of the PCA-ATMD. The results indicate that the absolute acceleration of the structure is well suppressed whether considering peak or root-mean-square responses. The experiment also demonstrates that the control of the PCA-ATMD can be decentralized, so that it is convenient to apply and maintain to real high-rise building structures.

• Journal of the Korean Society of Physical Medicine
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• v.18 no.4
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• pp.1-17
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• 2023

PURPOSE: The purpose of this study was to compare how the shoulder height and respiratory function are affected by applying shoulder stabilization exercises and core stabilization exercises that are effective for strengthening the trunk muscles and postural stability for adults with a round shoulder posture (RSP). METHODS: The participants were 28 young adults with RSP. They were assigned randomly to two groups: shoulder stabilization exercise and core stabilization exercise. They performed the exercises for 30 minutes twice a week for four weeks. They measured the shoulder height and respiratory function before and after exercise. RESULTS: No significant difference in shoulder height was found between the groups. A significant decrease in shoulder height was found in the shoulder stabilization exercise group after exercise. The core stabilization exercise group showed a significant decrease after exercise. In respiratory function, no significant difference was found between the groups. The forced vital capacity (FVC) and forced expiratory volume in one second (FEV₁) were increased significantly in the shoulder stabilization exercise group before and after exercise. The FEV₁, FEV₁/FVC, and peak expiratory flow were significantly higher in the shoulder stabilization exercise group after exercise than in the core stabilization exercise group. CONCLUSION: Shoulder stabilization exercise and core stabilization exercise improved the postural alignment and pulmonary function, and the exercises could be helpful in shoulder rehabilitation as well as the clinical part of the treatment of rounded shoulder posture.

• Korean Journal of Radiology
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• v.22 no.9
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• pp.1537-1546
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• 2021

Objective: To assess the role of arterial spin-labeling (ASL) perfusion MRI in identifying cerebral perfusion changes after indirect revascularization in children with moyamoya disease. Materials and Methods: We included pre- and postoperative perfusion MRI data of 30 children with moyamoya disease (13 boys and 17 girls; mean age ± standard deviation, 6.3± 3.0 years) who underwent indirect revascularization between June 2016 and August 2017. Relative cerebral blood flow (rCBF) and qualitative perfusion scores for arterial transit time (ATT) effects were evaluated in the middle cerebral artery (MCA) territory on ASL perfusion MRI. The rCBF and relative time-to-peak (rTTP) values were also measured using dynamic susceptibility contrast (DSC) perfusion MRI. Each perfusion change on ASL and DSC perfusion MRI was analyzed using the paired t test. We analyzed the correlation between perfusion changes on ASL and DSC images using Spearman's correlation coefficient. Results: The ASL rCBF values improved at both the ganglionic and supraganglionic levels of the MCA territory after surgery (p = 0.040 and p = 0.003, respectively). The ATT perfusion scores also improved at both levels (p < 0.001 and p < 0.001, respectively). The rCBF and rTTP values on DSC MRI showed significant improvement at both levels of the MCA territory of the operated side (all p < 0.05). There was no significant correlation between the improvements in rCBF values on the two perfusion images (r = 0.195, p = 0.303); however, there was a correlation between the change in perfusion scores on ASL and rTTP on DSC MRI (r = 0.701, p < 0.001). Conclusion: Recognizing the effects of ATT on ASL perfusion MRI may help monitor cerebral perfusion changes and complement quantitative rCBF assessment using ASL perfusion MRI in patients with moyamoya disease after indirect revascularization.

• Journal of Korean Society of Disaster and Security
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• v.16 no.4
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• pp.61-66
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• 2023

In this study, we analyzed the flooded area around Samcheok Middle School caused by typhoons MAYSAK·HAISHEN in September 2020. To analyze the confluence of Samcheok Osipcheon, local stream Deungbongcheon, we utilized Iber, a two-dimensional hydraulic model. We simulated the water depth and flood extent based on the peak flows on September 3 and September 7, 2020, and the 80 year and 100 year frequency floods. The simulation results showed that the 80-year frequency flood and the 100-year frequency flood on September 7 were insignificantly different, but the maximum flow rate from September 3 to September 7 was significantly different at 401 m³/s, resulting in a difference of 0.8 m in water depth and 7.1 m² in flood area. In addition, the analysis that considered only the contour lines using contour lines predicted inundation of not only the Samcheok Middle School playground but also the building, confirming the need to apply DSM.

• Journal of The Korean Society of Integrative Medicine
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• v.12 no.2
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• pp.55-63
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• 2024

Purpose : The purpose of this study is to determine the effects of scapula and pelvis symmetrical reciprocal pattern exercise of PNF concept on respiratory function and quality of life in elderly subjects. Methods : Nineteen elderly subjects with healthy were recruited. Subjects performed scapula and pelvis symmetrical reciprocal pattern exercise of PNF concept. Exercise was appied 30 minutes three times per week for four weeks. The respiratory function and quality of life (QOL) test three times (before, two weeks, and four weeks). Respiratory function includes forced vital capacity (FVC), forced expiratory volume at one second (FEV₁), Peak Expiratory Flow (PEF) and chest cage expansion test (CCET). The QOL test was measured Korean WHOQOL-BRIEF. The analysis method was analyzed through the one-way ANOVA repeated methods, and the statistical significance is α=.05. It was analyzed through the post test Bonferroni test. Results : After the 4 week scapula and pelvis symmetrical reciprocal pattern exercise of PNF concept showed statistically significant differences in the respiratory function (FVC, FEV₁, PEF, and CCET), and QOL (p<.05). As a result of the post-hoc test, FVC showed a significant increase in the mid test and post test compared to the pre test (p<.05), FEV₁ showed a significant increase in the post test compared to the pre test (p<.05). PEF showed a significant increase in all pre-test, mid-test, and post-test sections (p<.05), CCET showed a significant increase in all pre-test, mid-test, and post-test sections (p<.05). QOL showed a significant increase in all pre-test, mid-test, and post-test sections (p<.05). Conclusion : In this study, the scapula and pelvis symmetrical reciprocal pattern exercise of PNF concept improved respiratory function and QOL. The findings suggest that this intervention could be beneficial in improving respiratory function and QOL in the elderly.