• International conference on construction engineering and project management
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• 2009.05a
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• pp.1272-1277
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• 2009

Since improved capacity for RC bridges has been required due to deterioration or increase in traffic, the deflection of cracked reinforced concrete slabs need to be reconsidered. Strengthening is known as the better way to improve capacity of bridges than reconstructing. In this paper, Fiber Reinforced Plastic (FRP) was introduced as one of the best strengthening methods for civil structures. The structures strengthened with FRPs can improve the strengthening capacity and serviceability. Therefore, CFRP sheet and Glass Fiber-Steel Composite Plate (GSP) in this research were used for strengthening slabs of RC bridges. Experimental data from the strengthening will be helpful to better understand the effect of the strengthening and effective flexural rigidity.

• Journal of the Korea institute for structural maintenance and inspection
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• v.22 no.4
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• pp.100-107
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• 2018

The objective of this study is to assess the strengthening effects of fiber reinforced polymer(FRP) sheets such as Carbon fiber, Glass fiber, and PET(polyethylene terephthalate) on reinforced concrete flexural members. Variables of theoretical analysis are types of strengthening materials, material properties and amount of strengthening materials. A virtual flexural member without FRP sheets was created as a control specimen to understand the structural behavior of the non-strengthened specimen in terms of elastic and ultimate cross section. In total, 11 specimens including one non-strengthened and ten strengthened specimens were investigated. Various variables such as types of strengthening, strengthening properties, and amount of strengthening were studied to compare the behavior of the control specimen with those of strengthened specimens with regard to moment-curvature relationship. Results of theoretical analysis showed that the moment capacity of strengthened specimens was superior to that of the control specimen. However, the control specimen indicated the best ductility among all the specimens. As the amount of strengthening increased, flexural performance was improved. Furthermore, the results indicated that the ductile effect of members was affected by the ultimate strain of FRP sheets. The strengthening effect on the damaged member was similar to that on the non-damaged one since there was less than 10% difference in terms of flexural strength and ductility. Therefore, even if a damaged member is treated as non-damaged for analysis there is probably no noticeable difference.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.23 no.1
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• pp.53-58
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• 2017

Background: The purpose of this study was to effect of action observation with deep neck flexors strengthening exercise on pain and function in patients with chronic neck pain. Methods: Thirty patients with chronic neck pain were randomly action observation with deep neck flexors strengthening exercise group (AOT group; n=15) and deep neck flexors strengthening exercise group (FSE group; n=15). The intervention was applied for 50 minutes a day, 5 times a week for a total of 4 weeks. The intervention effect were evaluated before and after the intervention. visual analogue scale (VAS), pressure pain threshold (PPT), and Korea neck disability index (KNDI). Results: As a result of comparing within group, AOT group showed pre and post test, VAS (p<.01), PPT (p<.01), KNDI (p<.01) and FSE group VAS (p<.01), PPT (p<.05), KNDI (p<.01) significantly. In the comparison between the two groups, AOT group than FSE group in VAS, PPT and KNDI significantly (p<.05). Conclusion: Action observation with deep neck flexors strengthening exercise were founded to effective in reducing pain and improving function in patients with chronic neck pain. It is suggested as basic data of clinical intervention.

• Journal of the Korea Concrete Institute
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• v.23 no.6
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• pp.781-790
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• 2011

This paper contains the experimental results on strengthening effect of RC beams strengthened with NSM CFRP reinforcement and various strengthening details. A total of 14 beams have been tested to analyze strengthening effects of NSMR with various reinforcement details. Variables were cross-sectional shape of CFRP reinforcements, strengthening areas, grooves the number and location etc. Test results revealed that failure modes of NSMR showed two types. One was bond failure at interface between concrete and filler and the other was CFRP rupture. Also, failure mode of specimens with two grooves occurred premature bond failure because of superposition of failure surfaces at concrete around grooves. failure mode of MI specimens considered the equivalent section have changed bond failure to CFRP rupture and CFRP efficiency has improved 83% to 100%.

• Journal of the Korea institute for structural maintenance and inspection
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• v.12 no.1
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• pp.193-202
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• 2008

This paper investigates experimentally the confining effect, strengthening capacity and rebound rate of sprayed Fiber-Reinforced-Polymer (SFRP). From the method, resin and chopped fibers are sprayed separately from the nozzle with high pressure, and then they are attached to the concrete surface, so structure could be repaired. To evaluate the strengthening effect of sprayed FRP, cylindrical specimens and beam specimens were strengthening with SFRP. As main material of FRP, glass fiber and polyester resin are used. To investigate the optimum condition of sprayed FRP, the effects of fiber length, coating thickness, fiber volume ratio and concrete strength were examined. Capacities of sprayed FRP method were also compared to the FRP sheet method. In case of the sprayed FRP, rebound rate is important parameter considering economical efficiency and constructibility, so rebound rate of was discussed. From the test results, optimum conditions of sprayed FRP were determined. SFRP method showed superior strengthening capacities than FRP sheet method.

• Journal of Korean Academy of Rural Health Nursing
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• v.9 no.1
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• pp.19-32
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• 2014

Purpose: The strudy was done to determine the effect of an exercise program using the muscle strengthening flowchart on flexibility and hand strength and depression of rural elderly women. Methods: For 11 months, from January 9, to November 29, 2013, a survey was done of 37 voluntary participants who were elderly women living in rural areas. This study was a one group pretest-posttest Quasi-experimental research design to identify the effectiveness of self-directed programs. The Korean version of the depression measurement tool (Jo and Kim, 1993) was used. The collected data were analyzed using frequency, descriptive statistics, and paired t-test with SPSS /PC 17.0 program. Results: Comparison of before and after the self-directed program showed that flexibility (p <.001), left grip strength (p <.001), and right grip strength (p <.001) were significantly increased. Depression (p <.001) was significantly reduced. Conclusion: The results of the study show that the exercise program using the muscle strengthening flowchart resulted in of significant muscle strengthening and reduction in depression in rural elderly women. Future use of the muscle strengthening flowchart is recommended to provide long-term operational exercise programs.

• The Journal of Korean Academy of Orthopedic Manual Physical Therapy
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• v.20 no.1
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• pp.35-38
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• 2014

Background: The case study examined the effect of a hip joint traction and hip posterolateral muscles strengthening on knee pain, range of motion, and lower extremity function scale of patients with patellofemoral pain syndrome (PFPS). Although PFPS has previously been attributed to quadriceps dysfunction, more recent research has linked this condition to impairment of the hip musculature and kinematic. Methods: Subject is a 27-years-old female with PFPS. Performed hip joint traction with belt and posterolateral muscles(hip abductors, external rotators) strengthening for 4 weeks, 3 times a week, once a day. Before and after the therapy, measurements were made on the visual analog scale (VAS) and of the ROM, and a lower extremity functional scale (LEFS) was conducted. Results: The results showed positive changes in VAS and range of motion and lower extremity functional scale. First VAS of knee changed from 6 to 2. Second hip joint range of motion showed that internal rotation recored from $53^{\circ}$ to $58^{\circ}$ and external rotation recorded from $32^{\circ}$ to $37^{\circ}$. Third The lower extremity functional scale showed before therapy of 44; after therapy, 63. Conclusion: The hip joint traction and hip posterolateral muscles strengthening was effective in alleviating knee pain, increasing ROM and Lower extremity functional scale of the PFPS patients.

• Physical Therapy Rehabilitation Science
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• v.11 no.2
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• pp.189-197
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• 2022

Objective: The purpose of this study was to investigate the effect of a lower trapezius strengthening exercise program on an unstable support surface on pain, neck dysfunction, psychosocial factors, and postural alignment in neck pain patients with forward head posture. Design: A randomized controlled trial Methods: A total of 36 neck pain patients participated in this study. Screening tests were performed and assigned to experimental group (n=18) and control group (n=18) using randomization program. Both groups performed the lower trapezius strengthening exercise program. In addition, in the experimental group, an exercise program for lower trapezius muscle strengthening was performed on an unstable support surface. All interventions were performed 3 times a week, for a total of 5 weeks. quadruple visual analogue scale (QVAS), neck disability index (NDI), short form (SF)-12, and postural alignment were measured before and after the intervention to compare their effectiveness. Results: Both groups showed significant differences in QVAS, NDI, SF-12, and postural alignment before and after intervention (p<0.05). In addition, the experimental group showed significant differences in NDI and postural alignment compared to the control group (p<0.05). Conclusions: The lower trapezius strengthening exercise program on unstable support surfaces is an effective intervention method with clinical significance in improving neck disability and postural alignment in patients with neck pain with forward head posture.

• Journal of Electrical Engineering and Technology
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• v.10 no.6
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• pp.2413-2419
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• 2015

Core spinal muscles are related to trunk stability and assume the main role of stabilizing the spine during daily activities; strengthening of core muscles around the spine can therefore reduce the chance of back pain. The objective of the study was to investigate the effect of core muscle strengthening in the spine during spine stabilization exercise using a whole body tilt device. To achieve this, a validated musculoskeletal (MS) model of the whole body was used to replicate the input motion from the whole body tilting exercise. An inverse dynamics analysis was executed to estimate spine loads and muscle forces depending on the tilting angles of the exercise device. The activation of long and superficial back muscles such as the erector spinae (iliocostalis and longissimus) were mainly affected by the forward direction (-40°) of the tilt, while the front muscles (psoas major, quadratus lumborum, and external and internal obliques) were mainly affected by the backward tilting direction (40°). Deep muscles such as the multifidi and short muscles were activated in most directions of the rotation and tilt. The backward directions of the tilt using this device could be carefully applied for the elderly and for rehabilitation patients who are expected to have less muscle strength. In this study, it was shown that the spine stabilization exercise device can provide considerable muscle exercise effect.

• Steel and Composite Structures
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• v.24 no.5
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• pp.561-568
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• 2017

Steel frames are widely used in steel structures. Exiting steel structures may be needed to strengthen for various reasons. Carbon Fiber Reinforced Polymers (CFRP) is one of the materials that are used to strengthen steel structures. Most studies on strengthening steel structures have been done on beams and steel columns. No independent study, to the researcher's knowledge, has studied the effect of CFRP strengthening on steel frames. This study explored the use of CFRP composite on retrofitting square hollow section (SHS) steel frames, using numerical investigations. Ten Finite Element (FE) models, which were strengthened with CFRP sheets, were analyzed under different coverage length, number of layers, and location of CFRP composite. One FE model without strengthening was analyzed as a control FE model to determine the increase of the ultimate load in the strengthened steel frames. ANSYS software was used to analyze the SHS steel frames. The results showed that the coverage length and the number of layers of CFRP composite have a significant effect on increasing the ultimate load of the SHS steel frames. The results also showed that the location of CFRP composite had no similar effect on increasing the ultimate load and the amount of mid span deflection of the SHS steel frames.