• 한국주조공학회지
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• 제8권3호
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• pp.310-321
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• 1988

This study is aimed to investigate the effects of the multi-phase(ferrite-bainite-martensite) on the strengthening and toughening in ductile cast iron. All the specimen were austenitized at eutectoid transformation temperature range(${\alpha}+{\gamma}$) for 1hr and austempered at $300^{\circ}C$ and $400^{\circ}C$ for various holding time, and then quenched in iced water for multi - phase (${\alpha}-B-M$). When the volume fraction of martensite is below 15%, excellent maximum fracture load can be obtained due to strengthening by the fine martensite, but, with increasing of volume fraction over 15%, it was decreased drastically. The martensite size became finer and the shape of it changed from bar to spherical type with increasing of austempering holding time. The higher the austenitizing temperature is, the more preferential is the formation of austenite phase around the graphite nodules improving strength and toughness of austempered ductile cast iron.

• 국제물리치료학회지
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• 제4권2호
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• pp.557-561
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• 2013

The purpose of this study to identified the effect of muscle strengthening of ankle joints on postural sway. The subjects of this study were 29 healthy adults aged between 20 and 30 years(male 18, female 11). All subjects received ankle muscle strengthening exercise for 3 times, 3 sessions, 30 minutes per week over 4weeks period. The measured item of muscle strength, postural sway. Data collected from all subjects the result were as follows. The ankle strength showed significant increase(p<.05). One leg stand test with eye close increase in static balance(p<.05), left-right sway distance and anterior-posterior sway distance with eye open and close in static balance(p<.05). The result findings show that strength of the ankle joint muscles is a factor which affects postural sway and the ankle joints are important in static balance.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1999년도 봄 학술발표회 논문집(I)
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• pp.756-761
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• 1999

The objective of this study is to develop finite element analysis technique to predict the strength reduction of deteriorated reinforced concrete beams and their strengthening capacity. In order to consider the effect of rebar corrosion, a tension stiffening model is proposed and area reduction of rebars due to corrosion is considered. For the analysis of strengthened deteriorated RC beams, one dimensional truss element and an interface element are introduced for models of the strengthening composite and the interface between concrete and composite to simulate delamination or discontinuous behavior at the interface. Then, analyses for deteriorated RC beams strengthened with glass fiber reinforced epoxy panel (GFREP) are carried out to predict both flexural failure and plate-end delamination failure. Finally, analysis results are verified with experimental results.

• 한국철도학회:학술대회논문집
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• 한국철도학회 2007년도 추계학술대회 논문집
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• pp.1165-1173
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• 2007

Open-Steel-Plate-Girder railway bridges, in general, have plain concrete gravity pier without piles at foundations. Such piers are vulnerable to be overturned against braking forces and ground shakings during an earthquake. Thus, this study suggests a strengthening method using earth anchors to improve the resistance of plain concrete gravity piers to the overturn of themselves. Also, a filed test was performed for the as-built and the strengthened pier and the test results were compared to assess the strengthening effect. The earth anchors increased the ultimated capacity for the pier's overturn. Finally, a FE analysis was conducted using nonlinear elements for soil to understand the distribution of the soil stresses for the as-built and the strengthened pier.

• 한국콘크리트학회:학술대회논문집
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• 한국콘크리트학회 1998년도 가을 학술발표대회 논문집(III)
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• pp.815-820
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• 1998

Many composite girder bridges have been constructed for about thirty five years. Nowadays they are aged or deteriorated because of th increase in traffic and vehicle loads. In this study, the effect of strengthening with glass fiber sheet is investigated to estimate the possibility for appling for damaged prestressed concrete bridges. One normal and eight cracked specimens which had been preloaded were tested. The cracked specimens were strengthened with either external prestressing or bonding glass fiber sheet, or using both methods. The results showed that the maximum loads are almost same for both methods. So it seems that the strengthening with glass fiber sheet can be used for strengthening damaged prestressed concrete girders. It is important that proper devices should be selected to prevent glass fiber sheet from premature bonding failure below its maximum load, which is similar to end anchorage problem in external prestressing method. It is proved that the devices proposed in this paper have sufficient anchoring capability to increase load carrying capacity.

• The Journal of Korean Physical Therapy
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• 제14권2호
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• pp.133-144
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• 2002

This study aims at examining the effects of strengthening leg muscular strength on increasing elderly's muscular strength, walking ability and balance according to their experience of injury from a fall. It conducts muscular strength exercise for 4 weeks with 19 healthy old people over 65years and as a result of measuring their conditions for 6 weeks, it obtains the following conclusions. 1. Two groups showed a significant difference in their muscular strength, walking ability and balance according to the period(p<0.05). 2. Muscular strength and balance between the two groups showed a significant difference(p<0.05), but there was no significant difference in their walking ability(pgt;0.05). 3. Therefore, the exercise of strengthening leg muscular strength in this study has a significant effect on old people's walking ability and balance.

• 한국컴퓨터정보학회논문지
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• 제24권2호
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• pp.157-161
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• 2019

In this paper, the researcher investigated whether strengthening the back muscles affects the quality of chest compressions during cardiopulmonary resuscitation by university students. A total of 50 students majoring in healthcare were included from September 2018 to November. The participants performed chest compressions during cardiopulmonary resuscitation (CPR) for 2 min after back muscle strength was measured. Then, after adequate rest, the participants repeated the back muscle strength measurements and chest compressions after taping the erector spinae muscle. The paired t-test was performed to analyze changes in chest compression quality after taping. As results, taping enhanced back muscle strength and positively affected the depth of chest compressions and the compression to recoil ratio. Taping also increased confidence and lowered fatigability during chest compressions, so the participants preferred being taped while performing chest compressions. Based on these results, taping could help emergency room medical personnel specialized in CPR to enhance the quality of CPR and relieve back pain and fatigability by strengthening the back muscles.

• 산업기술연구
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• 제41권1호
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• pp.7-13
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• 2021

Fiber-reinforced polymer reinforcement or polyurea reinforcement techniques are applied to strengthen unreinforced masonry walls (UMWs). The out-of-plane reinforcing effect of sprayed glass fiber-reinforced polyurea (GFRPU), which is a composite elastomer made of polyurea and milled glass fibers on UMW, is experimentally verified. The out-of-plane strengths and ductile behaviors based on various coating shapes are compared in this study. An empirical formula to describe the degree of reinforcement on the out-of-plane strength of the UMW is derived based on the experimental results. It is reported that the peak load-carrying capacity, ductility, and energy absorption capacity gradually improve with an increase in the strengthening degree or area. Compared with the existing masonry wall reinforcement method, the GFRPU technique is a construction method that can help improve the safety performance along with ease of construction and economic efficiency.

• 한국건축시공학회:학술대회논문집
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• 한국건축시공학회 2023년도 봄 학술논문 발표대회
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• pp.341-342
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• 2023

This study empirically validates whether the effect of strengthening the legal regulations in the construction industry under the 'Construction Business Act' is true in order to expand the direct construction of the comprehensive construction corporation. Checking the effectiveness of the legal regulation that can force direct construction of the required scope of construction will not only be a logical background in the strengthening of law regulations but also suggest arguments that contradict some construction companies called legal regulation.

• 한국전문물리치료학회지
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• 제13권3호
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• pp.18-23
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• 2006

The limited walking ability after a stroke restricts a patient's independent mobility at home and in the community. It also brings about significant social handicaps. Therefore, it is necessary to improve walking ability in community-dwelling persons with stroke. The purpose of this study was to evaluate the effectiveness of gait training and muscle strengthening exercise of lower extremities in persons with chronic stroke. Nineteen community-dwelling individuals with stroke participated in this program. The exercise program lasted for seven weeks, with a 1-hour program twice per week, and it consisted of balance training, gait training, and strengthening of lower extremities. The outcome of the program was assessed by the gait speed, Wisconsin Gait Scale (WGS), Berg Balance Scale (BBS), and Stroke Impact Scale (SIS). Significant effects were found for the WGS, BBS, and mobility and hand function domain of the SIS (p<.05). It was found that short-term gait training exercise could improve quality of gait, balance, and mobility. Therefore, a more effective exercise program is required for community-based persons with stroke.