• Steel and Composite Structures
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• v.35 no.3
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• pp.385-404
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• 2020

Since the scaffold is composed of modular members, the total height of multi-story scaffolds does not often meet with the headroom of construction buildings. At this time, other supporting members need to be set up on the top of scaffolds. However, the mechanical behaviors of the combined system of scaffolds and other supporting members have seldom been discussed. This study explores the stability of the combined system of scaffolds and shores. The loading tests conducted in the laboratory show that the critical load of the combined system of two-story scaffolds and wooden shores is about half that of the three-story scaffold system with the same height. In the failure of both the "scaffold system" and the "combined system of scaffolds and shores' after loading, the deformation mainly occurs in the in-plane direction of the scaffold. The outdoor loading test shows that no failure occurs on any members when the combined system fails. Instead, the whole system buckles and then collapses. In addition, the top formwork of the combined system can achieve the effect of lateral support reinforcement with small lateral support forces in the outdoor loading test. This study proposes the preliminary design guidelines for the scaffolding structural design.

• The Journal of Korean Physical Therapy
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• v.30 no.3
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• pp.79-83
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• 2018

Purpose: The purpose of this study was to investigate the effects of combined training using proprioceptive neuromuscular facilitation (PNF) patterns and treadmills on the balance and walking ability of stroke patients. Methods: Twenty-three stroke patients were randomized into a control group (n=11), receiving only treadmill training and an experimental group (n=12) receiving combined training. The use of both PNF exercise and treadmill were implemented in the combined training. Interventions were performed 5 times a week for 6 weeks. Balance ability was measured by a timed up and go (TUG) test. Walking ability was measured by a 10-meter walk test (10MWT) and a 6-minute walk test (6MWT). A paired t-test was used to compare differences between pre- and post-intervention and independent t-tests were used to compare between groups. Results: Changes in TUG, 10MWT, and 6MWT before and after interventions were significantly different for both the experimental group and the control group (p<0.05). In addition, within-group changes in the TUG, 10MWT, and 6MWT were more effective in the experimental group than in the control group (p<0.05). Conclusion: Combined training using PNF techniques and treadmills may be useful in improving the balance and walking ability of stroke patients.

• Journal of the Korea institute for structural maintenance and inspection
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• v.21 no.1
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• pp.117-125
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• 2017

The role of fly ash in concrete become impotent with finding the characteristics of fly ash in which it is used as cement replacement material. In this paper, corrosion test results obtained by two test methods such as the long-term exposure corrosion test and the accelerated corrosion test method, were compared to investigated the corrosion resistance between fly ash concrete and normal concrete. Corrosion initiation time was measured in two types of concrete, i.e., one mixed with fly ash(FA) and the other without admixture(OPC). The accelerated corrosion test was carried out by four case, i.e., two samples is a cyclic drying-wetting method combined without carbonation(case 1) and combined with carbonation(case 2), and the other two samples is a artificial seawater ponding test method combined without carbonation(case 3) and combined with carbonation(case 4). Whether corrosion occurs, it was measures using half-cell potential method. The ponding test combined without carbonation was most effective in accelerating corrosion time of steel bars. The results indicated that the corrosion of rebar embedded in concrete occurred according to the order of OPC, FA. The delay relative ratio of corrosion obtained by corrosion initiation time between FA and OPC is 1.04 to 1.27. Consequently, fly ash concrete as the age increases its corrosion resistance was improved compared with OPC concrete.

• Journal of the Korean Geotechnical Society
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• v.16 no.1
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• pp.157-165
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• 2000

The applicability and performance of HMS-25 as the railroad roadbed materials were evaluated through the model and laboratory tests. The uniaxial compression test of HMS-25, model soil box test, and combined resonant column and torsional shear test were performed for static and dynamic analysis of railroad roadbed. The uniaxial compression test result of HMS-25 shows steady increase in strength due to hardening chemical reaction between HMS-25 and water. The result of model soil box test reveals that railroad roadbed of HMS-25 is better than that of soil in several aspects such as bearing capacity and settlement. The combined resonant column and torsional that shear test result indicates that shear modulus of HMS-25 increases with the power of 0.5 to the confining pressure and that shear modulus increases with the increase of curing period.

• Journal of Korean Biological Nursing Science
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• v.12 no.3
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• pp.157-165
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• 2010

Purpose: The purpose of this study was to examine the effects of recreation combined exercise program on body composition, physical fitness and depression in elderly women in rural district over a three-month follow-up period. Methods: Recreation combined exercise program (RCEP) was composed of resistance exercise, walking and recreation activity twice a week. The subjects were 52 divided in to experimental group (n=28) and control group (n=24). Arm curl, chair stand, 2 min step test, back scratch, chair sit and reach were measured as pre- or post-test data. Also, Depression was expressed using geriatric depression scale as pre- or post-test data. $X^2$ test, paired t-test and t-test were performed using SAS program. Results: Arm curl (p=.023), 2 minute step test (p<.001), back scratch (p=.004) and chair sit and reach (p=.024) showed the significant difference in the comparison between groups. Depression showed the significant difference in the comparison between groups (p=.008). Conclusion: These findings indicated the RCEP has positive influence upon increasing the physical fitness and improving the depression level. In conclusion, the regular RCEP will contribute to the improving physical and psychologic aspect in elderly women over the long period.

• PNF and Movement
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• v.22 no.1
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• pp.13-21
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• 2024

Purpose: This study investigated the effects of side walking training combined with squats on the balance and gait ability of stroke patients. The purpose of this study was to provide fundamental data regarding the use of side walking training combined with squats among stroke patients. Methods: Thirty patients with stroke were randomly divided into an experimental group (n=15) that underwent side walking training combined with squats and a control group (n=15) that performed general rehabilitation exercises. Both groups performed their respective exercises for 30 minutes, five times a week for six weeks. Balance was assessed using the functional reach test and timed up and go test, while gait ability was evaluated using the 10-meter walk test. A paired t-test was performed to compare within-group changes before and after the intervention. Differences between the experimental and control groups were analyzed using an independent t-test. For all tests, the level of statistical significance was set at α=0.05. Results: After the exercise, significant within-group improvements in balance and gait ability were observed in both the experimental and control groups (p<0.05). There was also a significant between-group difference in balance and gait ability following the intervention (p<0.05). Conclusion: While general rehabilitation is commonly employed in treating stroke patients and is relatively effective, the application of side walking training combined with squats may offer additional benefits in terms of improving balance and gait ability in these patients.

• Structural Engineering and Mechanics
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• v.17 no.2
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• pp.187-201
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• 2004

A shaking table test on a three-story one-bay steel frame model with metallic yield dampers and their parallel connection with oil dampers is carried out to study the dynamic characteristics and seismic performance of the energy dissipation system. It is found from the test that the combined energy dissipation system has favorable reducing vibration effects on structural displacement, and the structural peak acceleration can not evidently be reduced under small intensity seismic excitations, but in most cases the vibration reduction effect is very good under large intensity seismic excitations. Test results also show that stiffness of the energy dissipation devices should match their damping. Dynamic analysis method and mechanics models of these two dampers are proposed. In the analysis method, the force-displacement relationship of the metallic yield damper is represented by an elastic perfectly plastic model, and the behavior of the oil damper is simulated by a velocity and displacement relative model in which the contributions of the oil damper to the damping force and stiffness of the system are considered. Validity of the analytical model and the method is verified through comparison between the results of the shaking table test and numerical analysis.

• Physical Therapy Rehabilitation Science
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• v.12 no.1
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• pp.33-42
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• 2023

Objective: This study aims to analyze the effect of regular exercise through the combined walking-oriented aerobic and resistance exercises using EX1 in young adults. Design: Experimental one group pre and post test Methods: Participants comprised17 healthy young adults. All subjects performed a combined exercise program for 10 times using EX1. We measured quadriceps muscle thickness using ultrasound. Additionally, the hand grip strength test, and sit and reach test were performed before and after the exercise. Through paired t-test, we investigated whether there was a statistically significant difference in the measurement results after exercise program. Results: The rectus femoris muscle contraction ratio showed significant difference after exercise(P< 0.01). In the sit and reach test, flexibility showed significant difference after exercise(P < 0.01). The hand grip strength test also showed significant difference after exercise(P < 0.05). Conclusions: Healthy young adults can effectively perform various exercises commonly performed in daily life using EX1.

• Journal of the Korean Society for Railway
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• v.9 no.4 s.35
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• pp.349-356
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• 2006

At present, the selecting system and analytic estimation criterion on repair materials and methods of the deteriorated RC structures have not yet been set up in domestic. Under these circumstances, deterioration such as shrinkage crack, corrosion of rebar has been often occurred after repair, and this finally results in too frequent repairs. In this study, three types of repair methods were experimentally investigated by the accelerating test in a combined deterioration chamber and long-term field exposure test. Three types of repair methods applied in this study belong to a group of polymer cement mortar, which is commonly used in repair works. According to the results of this study, durability of repair mortar layers and corrosion properties of recovered rebar could be investigated in short period by the accelerating test in a combined deterioration chamber, which can simulate the condition of repeated high-and-low temperature and repeated dry-and-wet environment, spraying chloride solution and emitting $CO_2$ gas. After 36 month long-term filed exposure test in the coastal area, harmful macro-cracks are observed in the polymer cement mortar layer of some repair methods. These crack are considered to result from drying shrinkage of polymer cement mortar. Also, after 36 month exposure, amount of corrosion area and weight loss of rebar are found to be different according to the types of repair methods.

• Structural Engineering and Mechanics
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• v.73 no.5
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• pp.599-612
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• 2020

A combination of a gravity wall and an anchor beam is widely used to support the high soil deposit on rock mass. In this study, two groups of shaking table test were performed to investigate the responses of such combined retaining structure, where the rock masses were shaped with a flat surface and a curved surface, respectively. Meanwhile, the dynamic numerical analysis was carried out for a comparison or an extensive study. The results were studied and compared between the combined retaining structures with different shaped rock masses with regard to the acceleration response, the earth pressure response, and the axial anchor force. The acceleration response is not significantly influenced by the surface shape of rock mass. The earth pressure response on the combined retaining structure with a flat rock surface is more intensive than the one with a curved rock surface. The anchor force is significantly enlarged by seismic excitation with a main earthquake-induced increment at the first intensive pulse of Wenchuan motion. The value of anchor force in the combined retaining structure with a flat rock surface is generally larger than the one with a curved rock surface. Generally, the combined retaining structure with a curved rock surface presents a better seismic performance.