• 한국산학기술학회논문지
• /
• 제20권4호
• /
• pp.597-605
• /
• 2019

IPM Birdge는 경간장 30.0m에서부터 최대 120.0m까지 적용이 가능한 일체식 교량으로, 이러한 교량의 형상 조건은 라멘교에서도 적용가능하다. 교량의 형상조건은 유사하나 거동이 다른 IPM Bridge와 라멘교를 현장에 적용하기 위해, 두 교량의 공학적 우수성을 비교분석하는 과정이 필요하다. 본 연구에서는 라멘교와 IPM Bridge의 구조해석을 수행하여, IPM Bridge와 라멘교의 하중, 모멘트, 및 변위 등의 분포 형태를 비교분석하였다. 입력조건의 차이가 두 교량 형식의 거동에 영향을 미치지 않도록 동일한 조건에서 구조해석을 수행하였다. 구조해석은 경간 30.0m를 기준으로 단경간 교량부터 4경간 120.0m까지로 각 4개의 모델로 구조해석을 수행하였다. 본 연구로부터 도출된 결론은 다음과 같다. 1) 휨모멘트는 라멘교가 크게 산정되었고, 수평변위는 IPM Bridge가 크게 산정되었다. 2) 라멘교는 교량의 연장보다는 경간장에 의해 휨모멘트가 크게 도출되므로, 설계에서 경간장에 대한 허용 휨모멘트가 고려되어야 한다. 3) IPM Bridge의 파일벤트는 120.0m 경간에서도 강관말뚝의 소성모멘트를 초과하지 않았지만, 수축방향의 수평변위가 조인트 교량의 허용기준인 25mm에 근접하므로 설계 시 고려가 필요하다. 4) 실제 설계에서는 부재력에 대한 안정성을 확보하는 것이 중요하므로, 부 모멘트에 대한 검토가 가장 중요한 것으로 나타났다.

• 한국콘크리트학회:학술대회논문집
• /
• 한국콘크리트학회 2005년도 봄학술 발표회 논문집(I)
• /
• pp.475-478
• /
• 2005

This study was performed to evaluate about load bearing capacity of continuos IPC Girder Bridge under and after Construction. This is Ichi-1 Bridge that is 2-40m span continuous bridge on a extension road through the Ichun and the Naesa. The result of static loading test to use a 25ton truck after construction, deflection ratio is 0.64 that is $35\%$ and average of response ratio is 0.48$\~$0.89 that is less than theoretical value. The result of dynamic loading test, the number of proper vibrations is 3.06Hz that is like theoretical value 3.61Hz, the modulus of impact is 0.235 that is bigger than specification 0.19. the load bearing capacity is minimum DB-40 that is so big value. In the result, continuos IPC Girder Bridge is safe in short period. we will evaluate long period behavior of continuos IPC Girder Bridge.

• The Journal of Korean Physical Therapy
• /
• 제28권3호
• /
• pp.205-211
• /
• 2016

Purpose: This study investigated the influence of muscle activity of the trunk and lower limb during a bridge exercise using a unstable surface and during one-legged bridge hip abduction in healthy adults. Methods: Nineteen healthy participated in this study (12 males and 7 females, aged $29.0{\pm}5.0$). The participants were instructed to perform the bridge exercises under six different conditions. Trunk and lower limb muscle activation, such as the erector spinae (ES), gluteus maximus (GM), external oblique (EO), and internal oblique (IO), was measured using surface electromyography. The six different bridge exercise conditions were conducted randomly. Data analysis was performed by using the mean scores after three trials of each condition. Results: On the ipsilateral side, muscle activity of the IO, EO, and ES during the hip abduction condition (Single-legged hip abduction bridge, Bridge with use of a ball and single-leg hip abduction, Bridge with use of a sling and single-leg hip abduction) was significantly higher than those during Unstable surface (Bridge with use of a ball, Bridge with use of a sling) and General bridging exercise (p<0.05). In the contralateral side, activities of the GM and EO during Single-legged hip abduction bridge, Bridge with use of a ball and single-leg hip abduction and Bridge with use of a sling and single-leg hip abduction was significantly higher than that during Bridge with use of a ball, Bridge with use of a sling and General bridging exercise (p<0.05). Conclusion: This study demonstrated that performing a bridge exercise with use of a sling and single-leg hip abduction had an effect on trunk and gluteal muscle activation. The findings of this study suggest that this training method can be clinically effective for unilateral training and for patients with hemiplegia.

• Computational Structural Engineering : An International Journal
• /
• 제2권1호
• /
• pp.11-17
• /
• 2002

Cost-effectiveness in design is considered for determining the target reliability of concrete bridges under seismic actions. This objective can be achieved based on the economic optimization of the expected life-cycle cost of a bridge, which includes initial cost, direct losses, and indirect losses of a bridge due to strong earthquakes over its lifetime. A separating factor is defined to consider the redundancy of a transportation network. The Park-Ang damage model is employed to define the damage of a bridge under seismic action, and a Monte Carlo method based on the DRAIN-2DX program is developed to assess the failure probability of a bridge. The results for an example bridge analyzed in this paper show that the optimal target failure probability depends on the traffic volume carried by the bridge and is between 1.0×10/sup -3/ to 3.0×10/sup -3/ over a life of 50 years.

• The Journal of Advanced Prosthodontics
• /
• 제6권4호
• /
• pp.253-258
• /
• 2014

PURPOSE. To compare marginal and internal gaps of zirconia substructure of single crowns with those of three-unit fixed dental prostheses. MATERIALS AND METHODS. Standardized Co-Cr alloy simulated second premolar and second molar abutments were fabricated and subsequently duplicated into type-III dental stone for working casts. After that, all zirconia substructures were made using $Lava^{TM}$ system. Marginal and internal gaps were measured in 2 planes (mesial-distal plane and buccal-palatal plane) at 5 locations: marginal opening (MO), chamfer area (CA), axial wall (AW), cusp tip (CT) and mid-occlusal (OA) using Replica technique. RESULTS. There were significant differences between gaps at all locations. The $mean{\pm}SD$ of marginal gap in premolar was $43.6{\pm}0.4{\mu}m$ and $46.5{\pm}0.5{\mu}m$ for single crown and 3-unit bridge substructure respectively. For molar substructure the $mean{\pm}SD$ of marginal gap was $48.5{\pm}0.4{\mu}m$ and $52.6{\pm}0.4{\mu}m$ for single crown and 3-unit bridge respectively. The largest gaps were found at the occlusal area, which was $150.5{\pm}0.5{\mu}m$ and $154.5{\pm}0.4{\mu}m$ for single and 3-unit bridge premolar substructures respectively and $146.5{\pm}0.4{\mu}m$ and $211.5{\pm}0.4{\mu}m$ for single and 3-unit bridge molar substructure respectively. CONCLUSION. Independent-samples t-test showed significant differences of gap in zirconia substructure between single crowns and three-unit bridge (P<.001). Therefore, the span length has the effect on the fit of zirconia substructure that is fabricated using CAD/CAM technique especially at the occlusal area.

• 대한물리치료과학회지
• /
• 제30권3호
• /
• pp.31-40
• /
• 2023

Background: The purpose of this study was to confirm the effect of bridge exercise combined with vibration on abdominal muscle thickness. Design: Randomized controlled trial. Methods: As study subjects, 24 adults in their 20s were classified into 12 vibration bridge exercise groups and 12 bridge exercise groups. The time was divided into before the experiment, 3 weeks after the experiment, and 6 weeks after the experiment. Two-way repeated ANOVA was used to examine changes in the muscle thickness of the external oblique, internal oblique, and transverse abdominal muscles of the trunk muscles, and the significance level was set at 0.05. If there was an interaction between time and group, post-hoc analysis was performed, and the significance level was set at 0.01. Results: There was a significant difference in the external oblique muscle in the change by period, the interaction between time and group, and the change between groups (p<0.05). There was a significant difference in the external oblique muscle in the change by period, the interaction between time and group, and the change between groups (p<0.05). Conclusion: As a result of this study, bridge exercise combined with vibration had a positive effect on the muscle thickness of the external oblique, internal oblique, and transversus abdominis muscles. It suggests the possibility of using the basic data of vibration exercise and the lumbar stabilization exercise in clinical practice.

• 대한수학회논문집
• /
• 제19권3호
• /
• pp.531-544
• /
• 2004

We study a family of 2-bridge knots with 2-tangles in the 3-sphere admitting a genus two 1-bridge splitting. We also observe a geometric relation between (g - 1, 1)-splitting and (g,0)- splitting for g = 2,3. Moreover we construct a family of closed orientable 3-manifolds which are n-fold cyclic coverings of the 3-sphere branched over those 2-bridge knots.

• 한국강구조학회 논문집
• /
• 제24권3호
• /
• pp.349-360
• /
• 2012

본 논문은 GFRP 슬래브 교량 상부구조에 대한 장기성능, 내하력, 사용성 및 구조적 안전성의 상세한 평가를 기술하고 있다. 국내 최초로 완전 GFRP 슬래브 교량이 2002년 5월에 가설되었다. GFRP 슬래브 교량은 단순지지로 지간 10.0 m, 폭 8.0 m 인 2차선으로 설계되었다. 본 GFRP 슬래브교량은 콜루게이트(corrugate) 심재를 갖는 샌드위치 구조로서 유리섬유와 비닐 에스테르를 사용하여 수적층으로 제작되었다. GFRP 슬래브 교량의 장기성능 평가는 2002년 수행되었던 동일한 현장재하시험으로 2004, 2011년에 실시되었다. GFRP 슬래브교량은 예상되었던 대로 공용 중에서 구조적 문제점이 없이 성능이 잘 발휘되고 있었음을 평가를 통하여 나타내고 있다. 본 평가 자료는 GFRP 슬래브 교량의 내하력 평가에 대한 기초자료와 완전 GFRP 슬래브교량 상부구조의 장기성능의 일부자료로서 제공될 수 있을 것이다.

• 한국산학기술학회논문지
• /
• 제19권3호
• /
• pp.96-103
• /
• 2018

교량의 온도 설계하중의 기준이 되는 유효온도는 통계적 방법에 의한 분석이 일반적으로 사용된다. 본 연구에서는 통계적 방법을 개선할 수 있는 인공신경망을 구축하여 유효온도를 산정하였다. 강상자형교 시험체를 폭 2.0m, 높이 2.0m, 길이 3.0m, 상부슬래브 0.2m로 제작하였다. 21개의 온도 게이지를 부착하여 3년간(2014~2015) 온도를 측정하였다. 2014~2015년 측정된 온도데이터를 바탕으로 인공신경망을 학습시키고, 그 결과를 Euro code와 비교하였다. Euro code와 통계분석값과의 오차율은 전체 측점에 대하여 4.1%로 분석되었다. 2016년 측정된 온도데이터를 이용하여 인공신경망을 검증하고, 교량 유효온도를 산정하였다. 이 결과는 통계분석 값과 약 3.97%의 차이를 보였다. 이 정도의 오차율은 인공신경망에 의한 분석이 공학적인 측면에서 수용할 수 있는 크기인 것으로 판단된다. 인공신경망은 교량의 온도하중 설계 시 그 지역의 최고 대기온도, 교량 형식, 상부 아스팔트 두께 등 입력 값만 알면 교량의 유효온도를 간편히 예측해 줄 수 있다.

• 대한치과기공학회지
• /
• 제6권1호
• /
• pp.11-14
• /
• 1984

The auther performed this experimental study on cervical margin distortion in preheating method during soldering. 1. In soldering methods, the method using the furnace has less distortion than the method using open-flame and longer the bridge spon, the larger the distortions. 2. Table Ⅰ Showed that buccal margin, lingual margin, mesial margin and distal margin had respectively 0.01mm, 0.02mm, 0.03mm, 0.03mm closer adaptation in 3 unit bridge than in 5 unit bridges. 3. Table II showed that buccal margin, lingual margin, mesial margin and distal margin had respectively 0.06mm, 0.07mm, 0.11mm, 0.05mm closer adaptation in 3 unit bridge than in 5 unit bridges.