• Proceedings of the Korea Concrete Institute Conference
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• 2004.05a
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• pp.68-71
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• 2004

In the shear strengthening with FRP sheets, beams are wrapped around the webs and tension face of critical shear span by fiber sheets. The shear strength of RC beam strengthened with FRP sheets must be calculated based on the effective strain that can be developed in the FRP sheets at ultimate stage because the final failure modes of beams are governed by premature debonding of FRP sheet due to the limitation of bonded length by beam depth. An experimental study is carried out to evaluate the shear strengthening effect of AFRP or GFRP sheets with respect to shear reinforcement ratio of rebar. From the test results, it was found that the additional shear strength provided by GFRP or AFRP can be estimated by $p_w{\cdot}f_w$ based on the maximum effective strain of FRP sheet $4,000m{\mu}$ proposed by ACI 440 committee.

• Journal of Technology Innovation
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• v.15 no.1
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• pp.145-173
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• 2007

Using patent and firm-level panel data for 1982-2001, this study investigates spillover effects of patents and the strengthening of intellectual property rights on Productivity and Innovation. As well as we consider the effect of intra-industry spillovers, we extend the effect to inter-industry spillovers which implies the effects of IT industries on non-IT industries. The empirical results are summarized as follows. First, allowing for firm-level variables, market competition and technological spillovers, the strengthening of intellectual property rights does not play a significant role on innovative activities. Second, while innovative activities of domestic firms affect significantly firms' innovative activities, those of foreign firms do not. Third, innovative activities of IT industries as inter-industry spillovers play a significant role on innovative activities and labor productivities of domestic firms.

• Journal of Korean Physical Therapy Science
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• v.6 no.1
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• pp.923-929
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• 1999

The purpose of this study was to identify that the effect of the Lumbar extensor strengthening exercise on the trunk range of motion(Lumbar extensor strengthening exercise group = 15, Control group = 15). To find out the improvement of trunk range of motion, each group was examined with Modified Modified Sch ber(MMS) measurement before and after the treatments. The result are as followed. 1. After the training period, the trunk range of motion were increased in both groups. 2. After the training period, both groups revealed no sinigificant difference on the trunk range of motion.

• Journal of the Korea institute for structural maintenance and inspection
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• v.3 no.4
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• pp.145-153
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• 1999

The major objective of this study is to investigate experimentally the shear strengthening effect of carbon fiber sheets upon reinforced concrete deep beam and shear failure behavior variation of reinforced concrete deep beam strengthened by carbon fiber sheets. Tests are carried out with 6 specimens were shear failure at first loading tests, and with parameters including the types of shear strengthening of carbon fiber sheets (I type, S type, U type), and plies of sheets (2 ply and 1 ply). From the results of test, analyzed load-deflection of midspan, strain variation of main bars and transverse reinforcement, maximum load capacity of strengthened specimens, and compared with the previous test results.

• Journal of the Korea institute for structural maintenance and inspection
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• v.5 no.1
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• pp.228-236
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• 2001

When RC beams are strengthened for flexure with steel plate, reinforced member has initial strain due to the dead load and is subject to partial damage. Strain of steel strengthening is zero at initial state. The effect of strengthening flexural member might be influenced by the quantity of initial strain. In this study, when He beams are strengthened for flexure with steel plate, its behavior is experimentally compared for the reinforcement efficiency of members due to the existence of different levels of initial strain. It is confirmed that reinforcement efficiency varies depending on the difference of initial strain.

• Proceedings of the Korea Concrete Institute Conference
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• 2005.05a
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• pp.259-262
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• 2005

Numerous studies showed that safety and serviceability of many concrete infrastructures and buildings built in 1970's have capacity less than their design capacities and thereby require immediate retrofitting. Currently, these aged concrete structure are being repaired using many repair and strengthening methods developed in the past. Therefore, in this study, a repairing and strengthening method for retrofitting high strength concrete columns that can effectively improve the performance of high strength concrete columns is developed. The square high strength concrete column's cross-sectional shape is modified to octagonal shape by attaching precast members on the surface of the column. Then, the octagonal column surface is wrapped using Carbon Fiber Sheets (CFS). The method allowed the maximum usage of confinement effect of externally wrapped CFS, which resulted in improved strength and ductility of repaired high strength concrete columns.

• Journal of the Korea institute for structural maintenance and inspection
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• v.6 no.4
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• pp.243-254
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• 2002

This study investigates the structural behavior of cracked or uncracked RC columns retrofitted with CFS and evaluates the shear retrofit performance through experiment. Experimental works were conducted for sixth specimens varied in the adhesion method of CFS, the ratio of shear reinforcement bar, and the existence of crack before retrofitting. Throughout cyclic test, the strength, stiffness, failure modes, and ductility are discussed. The test results show that the retrofitting method with CFS improve the shear strength and ductility. The crack width below 2mm, occurred before retrofitting, didn't reduce the shear strengthening effect.

• The Journal of Korean Physical Therapy
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• v.11 no.2
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• pp.149-161
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• 1999

The purpose of study wan to compare the effect of balance performance in the elderly by the strengthening exercise. Thirty-one health elderly women aged 60 to 79 years participated in this study. Participants were divided into exercise(21) and control group(10). Exercise participants received strengthening exercise for 45 minutes in three times a week for 6 weeks while control subjects continued their normal activities, Exercise included resisted hip flexion, extension, abduction and adduction, knee flexion and extension, ankle dorsiflexion and plantrarflexion. All subjects were assessmented clinical test of sensory interaction and balance. one leg stance test, Berg balance test. Exercise and control subjects were teated before, midway through, and at the end of the trial. These collected data were analyzed by using oneway and repeated ANOVA, scheffe's test, 1-test and correlation. The results of this study were as fellows. 1. There were statistically significant difference in balance performance clinical teat of sensory interaction, and balance(p<.01), one leg stance test(p<.05), Berg balance test(p<.05) by the strengthening exercise. 2. There was correlation between static balance and dynamic balance(p<.01). 3. There was correlation between static balance and weight(p<.05), dynamic balance and height(p<.01), and weight(p<.01).

• Steel and Composite Structures
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• v.25 no.5
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• pp.593-601
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• 2017

Carbon Fiber Reinforced Polymer (CFRP) is one of the materials used to strengthen steel structures. Most studies on strengthening steel structures have been done on steel beams and steel columns. No independent study, to the researcher's knowledge, has studied the effect of CFRP strengthening on steel beam-columns, and it seems that there is a lack of understanding on behavior of CFRP strengthening on steel beam-columns. However, this study explored the use of adhesively bonded CFRP flexible sheets on retrofitting square hollow section (SHS) steel beam-columns, using numerical investigations. Finite Element Method (FEM) was employed for modeling. To determine the ultimate load of SHS steel beam-columns, ten specimens, eight of which were strengthened with the different coverage length and with one and two CFRP layers, with two types of section (Type A and B) were analyzed. ANSYS was used to analyze the SHS steel beam-columns. The results showed that the CFRP composite had no similar effect on the slender and stocky SHS steel beam-columns. The results also showed that the coverage length, the number of layers, and the location of CFRP composites were effective in increasing the ultimate load of the SHS steel beam-columns.

• PNF and Movement
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• v.15 no.1
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• pp.97-104
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• 2017

Purpose: This study seeks to determine the effect of a lower extremity strengthening exercise that uses proprioceptive neuromuscular facilitation (PNF) on the gait and balance ability of a stroke patient. Methods: In this case study, a lower extremity strengthening exercise that used PNF was performed by the subject for 30 minutes 4 times per week for a 4-week period alongside typical rehabilitation therapy. The lower extremity pattern used flexion-abduction-internal rotation with knee flexion, extension-abduction-internal rotation, bilateral leg extension pattern. The 10 m walk test and 6 minute walk test were used to assess gait ability. The Berg balance scale was used to assess balance ability. Results: After the intervention, the time for the 10 m walk test decreased by 5.72 sec, the distance for the 6 minute walk test decreased by 20 meters, and the score on the Berg balance scale improved by 7 points, which indicates the effectiveness of this therapy for stroke patients. Conclusion: The results of this study indicate that a lower extremity strengthening exercise using PNF can improve the gait ability and balance ability of stroke patients.