• 웰빙융합연구
• /
• 제5권1호
• /
• pp.31-35
• /
• 2022

Purpose: This study was conducted to investigate the effects of change in the unstable support surface location during bridge exercise on the muscle activity of erector spinae and gluteus maximus. Research design, data and methodology: 12 healthy participants aged 23.32 ±1.02 were measured muscle activities of erector spinae and gluteus maximus during bridge exercise and compared between the exercise conditions; unstable support surface located on upper back and feet during bridge exercise. Paired t-test was performed to identify whether there was a significant difference in the muscle activities between the exercise conditions. Results: As a result, even though higher levels of the averaged muscle activities of both erector spinae and gluteus maximus during exercise in unstable support surface located on feet than upper back were observed, no significant differences were found. Conclusions: The change of unstable support surface location during bridge exercise for low back pain rehabilitation would be more appropriate to be used to increase levels of tension of muscle activities and train fine motor control rather than to strengthening muscle strength.

• 한국콘텐츠학회논문지
• /
• 제11권11호
• /
• pp.42-48
• /
• 2011

본 논문에서는 교량구간의 도로 결빙예측 및 감지를 위한 시스템 설계를 제안하였다. 센서 노드의 하드웨어는 마이크로프로세서, 온도 센서, 습도 센서, 그리고 Zigbee 무선 통신으로 구성되었다. 관제센터의 소프트웨어는 관제센터에 수집된 교량 온도, 습도 데이터로 관찰하기 위하여 구현되었다. 교량 노면의 결빙은 노면의 온도가 이슬점 온도 이하이면서 영하일 때 발생한다. 제안된 시스템을 이용하여 도로면의 온도 및 습도 분포를 측정하였다. 측정 데이터는 도로 결빙이 발생하는 시점을 예측하기 위하여 사용되었다. 실제 결빙되는 것보다 최소 30분 이전에 결빙시점을 예측하여 경고가 이루어진다. 이 결과로 결빙으로 인한 교통사고를 방지하기 위하여 사용 할 수 있다.

• 대한정형도수물리치료학회지
• /
• 제23권1호
• /
• pp.23-30
• /
• 2017

Purpose: The purpose of this study was to investigate the effect of transverse abdominis ratio and balance ability during bridge exercises on different support surface. Methods: The subjects were 20 students at G University. Ultrasound equipment was used to measure the transverse abdominisratio and the computerized balance measurement equipment was used to measure the balance ability before and after bridge exercises on different support surface. Results: Transverse abdominis ratio change between the groups was a significant difference only in the unstable support surface training group (p<.05). Normal standing eye close balance ability change between the groups was significantly different only in the unstable support surface training group (p<.05). The changes in the transverse abdominis ratio after 7 days of exercise and 14 days after exercise were significantly different between the groups (p<.05). Normal standing eye close balance ability showed a significant difference at 7 days after exercise and 14 days after exercise (p<.05). Conclusions: It is more effective to balance ability and ratio of the transverse abdominis when bridge exercises on an unstable support surface than to perform bridge exercises on a stable support surface. Therefore, we propose an effective program for patients with instability of the lumbar in clinical practice. bridge exercises on different support surface.

• Structural Engineering and Mechanics
• /
• 제11권3호
• /
• pp.259-272
• /
• 2001

The impact behavior of a multigirder concrete bridge under single and multiple moving vehicles is studied based on correlated road surface characteristics. The bridge structure is modeled as grillage beam system. A 3D nonlinear vehicle model with eleven degrees of freedom is utilized according to the HS20-44 truck design loading in the American Association of State Highway and Transportation Officials (AASHTO) specifications. A triangle correlation model is introduced to generate four classes of longitudinal road surface roughness as multi-correlated random processes along deck transverse direction. On the basis of a correlation length of approximately half the bridge width, the upper limits of impact factors obtained under confidence level of 95 percent and side-by-side three-truck loading provide probability-based evidence for the evaluation of AASHTO specifications. The analytical results indicate that a better transverse correlation among road surface roughness generally leads to slightly higher impact factors. Suggestions are made for the routine maintenance of this type of highway bridges.

• 대한물리의학회지
• /
• 제11권3호
• /
• pp.1-9
• /
• 2016

PURPOSE: The purpose of this study was to identify the effects on flexibility of bridge and plank exercises using sling suspension on an unstable surface. METHODS: The subjects of this study were 20 healthy adults in their 20s (plank=10, bridge=10). Both types of exercise were performed three times per week for a period of four weeks. Each exercise was performed in the front and side direction. Exercise intensity was altered through the use of a sling, which was placed at the knee and ankle. Flexibility at trunk forward flexion and backward extension was measured. The trunk forward flexion was measured at sitting position. The trunk backward extension was measured at prone position. The data were analyzed by Two-way ANOVA. RESULTS: There were significant differences in the pre- and post-test for both the bridge and plank exercise groups. In the bridge exercise, significant differences were shown in the trunk forward flexion and the trunk backward extension (p<.05). In the plank exercise, a significant difference was shown in the trunk backward extension (p<.05). No significant differences were noted in interaction effect or the main effects in either group. CONCLUSION: Bridge and plank exercises on an unstable surface improve flexibility. The bridge exercise improves the flexibility of the forward and backward muscles of the trunk. The plank exercise improves the flexibility of the forward muscles of the trunk. This information would be useful in the development of exercise programs including bridge and plank exercises for improving flexibility and core stability.

• 대한통합의학회지
• /
• 제7권4호
• /
• pp.291-300
• /
• 2019

Purpose : This study focuses on the influence of bridge exercise combined with whole body vibration on muscle activity and balance. Methods : 30 stroke patients were recruited for subjects. The subjects were divided to bridge exercise combined stable surface (Group I), bridge exercise combined unstable surface (Group II), and bridge exercise combined bridge exercise (Group III), of which 10 subjects were randomly allocated. The subjects were given 30 minutes of neurologic physical therapy which included gait training and muscular strength training, and additionally given 30 minutes of bridge exercise combined stable surface, bridge exercise combined unstable surface, and bridge exercise combined whole body vibration for each group, five times a week, for 8 weeks. Their muscle activity and balance were analyzed before the intervention. After 8 weeks of the intervention, the mentioned parameters were measured once more for between-group analysis. Results : Comparative analysis of the muscle activity and balance between the groups showed statistically significant difference, and post-hoc analysis showed the Group III had greater changes in muscle activity and balance than Group Iand Group II. Conclusion : Such results revealed that bridge exercise combined with whole body vibration is effective in muscle activity and balance. Based on the current study, more effective program is to be proposed for elite athletes as well as stroke patients. Based on the current study, studies that incorporates various frequencies of vibration is required for development of effective whole body vibration exercise program.

• Steel and Composite Structures
• /
• 제18권6호
• /
• pp.1479-1492
• /
• 2015

This study evaluated the localized stress condition of the real corroded deck surface of an orthotropic steel bridge because severe corrosion damage on the deck surface and fatigue cracking were reported. Thus, a three-dimensional finite element (FE) analysis model was created based on measurements of the corroded orthotropic steel deck surface to examine the stress level dependence on the corrosion condition. Based on the FE analysis results, it could be confirmed that a high stress concentration and irregular stress distribution can develop on the deck surface. The stress level was also increased by approximately 1.3-1.5 times as a result of the irregular corroded surface. It was concluded that this stress concentration could increase the possibility of fatigue cracking in the deck surface because of the surface roughness of the orthotropic steel bridge deck.

• 한국강구조학회 논문집
• /
• 제9권3호통권32호
• /
• pp.309-321
• /
• 1997

차량이 교량을 통과할 때 교량에 발생하는 충격계수는 교량의 설계시 매우 중요한 인자이다. 본 연구에서는 2연속 강판형교의 지간 중앙점에 발생하는 충격계수에 관한 실험 및 해석적 연구를 수행하였다. 교량의 수치해석시 교량과 차량은 3차원으로 모델링하였으며. 교량의 노면조도는 Intelligent Total Station으로 직접 측정하여 사용하였다. 이때 교량의 주형은 보요소, 콘크리트 바닥판은 쉘요소를 사용하고 주형과 콘크리트 바닥판 사이는 Rigid Link를 사용하여 연결시켰다. 교량과 차량 사이의 상호작용을 고려하여 차량의 운동방정식을 유도하였으며, 차량의 여러 가지 주행속도에 따른 교량의 지간 중앙점에서의 충격계수를 구하여 우리나라 및 외국의 시방서 규정과 비교 검토하였다.

• Structural Monitoring and Maintenance
• /
• 제2권1호
• /
• pp.65-75
• /
• 2015

Among the destruction instances of half-through arch bridges, the shorter hangers are more likely to be ruined. For a thorough investigation of the hanger system durability, we have studied vehicle impact effect on hangers with vehicle-bridge coupling method for a half-through concrete-filled-steel-tube arch bridge. A numerical method has been applied to simulate the variation of dynamic internal force (stress) in hangers under different vehicle speeds and road surface roughness. The characteristics and differences in impact effect among hangers with different length (position) are compared. The impact effect is further analyzed comprehensively based on the vehicle speed distribution model. Our results show that the dynamic internal force induced by moving vehicles inside the shorter hangers is significantly greater than that inside the longer ones. The largest difference of dynamic internal force among the hangers could be as high as 28%. Our results well explained a common phenomenon in several hanger damage accidents occurred in China. This work forms a basis for hanger system's fatigue analysis and service life evaluation. It also provides a reference to the design, management, maintenance, monitoring, and evaluation for this kind of bridge.

• 한국전산구조공학회:학술대회논문집
• /
• 한국전산구조공학회 2006년도 정기 학술대회 논문집
• /
• pp.772-777
• /
• 2006

An acoustic finite element model of a bridge is developed to evaluate the noise generated by the traffic-induced vibration of the bridge. The dynamic response of a multi-girder bridge, modeled by a 3-dimensional frame element model, is analyzed with a 3-axle(8DOF) truck model and a 5-axle(l3DOF) semi-trailer. The flat plate element is used to analyze the acoustic pressure due to the fluid-structure interactions between the vibrating surface and contiguous acoustic fluid medium. The radiation fields of noise with a specified distribution of vibrating velocity and pressure on the structural surface are also computed using the Kirchhoff-Helmholtz integral. In an attempt to illustrate the influence of the structural vibration noise of a bridge to total noise level around the bridge, the random function is used to generate the vehicle noise source including the engine noise and the rolling noise interacting between the road and tire. Among the diverse parameters affecting the dynamic response of bridge, the vehicle velocity, the vehicle weight, the spatial distribution of the road surface roughness, the stiffness degradation of the bridge and the variation of the air temperature changing the air density are found to be the main factors that increase the level of vibration noise. Consequently, The amplification rate of noise increases with the traveling speed and the vehicle weight.