• Title/Summary/Keyword: 조기하중

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Early loading on a maxillary posterior single implant with deepened threads: a case report (깊은 나사선을 갖는 임플란트를 이용한 상악 구치부 조기 하중: 증례보고)

  • Han, Chang-Hoon;Kim, Hyun-Seung;Park, Sang-Won;Yun, Kwi-Dug;Joo, Han-Sung;Lim, Hyun-Pil
    • Journal of Dental Rehabilitation and Applied Science
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    • v.30 no.3
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    • pp.253-258
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    • 2014
  • This case report shows an early loading at the maxillary posterior area with the wide diameter implant which has a deepened threads after removal of failed implant. Implant Stability Quotient (ISQ) value has represented favorable result for one year. This clinical report describes the potential of early loading on a maxillary posterior single implant with deepened threads.

Premature Failure Load of Reinforced Concrete Beams with Flexural Strengthened by Steel Plates (강판으로 휨 보강된 철근콘크리트 보의 조기파괴하중 산정)

  • Kim, Haeng-Jun;Kim, Woo
    • Journal of the Korea institute for structural maintenance and inspection
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    • v.9 no.1
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    • pp.283-292
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    • 2005
  • This paper predicts premature failure load of reinforced concrete beams by epoxy-boned partially steel plates. A parametric study is conducted to estimate premature failure load of beams such as with or without stirrups, unplated length ratio, steel and reinforcement ratio, shear span to depth ratio of reinforcement beam. By results of finite element analysis, it turned out that the unplated length played a dominant role in partially plated beams but reinforcement ratio and shear span to depth ratio effected the premature failure load. The approximate expression with regard to combined design variables is compared with experimental results. It shows closely agreement.

원형 실린더에 의한 3차원 비선형 산란 문제의 수치해석

  • 성홍근;최항순
    • Proceedings of the Korean Society of Coastal and Ocean Engineers Conference
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    • 1998.09a
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    • pp.88-93
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    • 1998
  • 수치 파수조기법은 해양구조물에 작용하는 비선형 파랑하중을 해석할 수 있는 가장 유망한 도구로 인식되고 있다. 이러한 수치 파수조기법은 새롭고 다양한 형태의 해양구조물에 대한 정확하고 엄밀한 설계는 물론이고, 실험 조파수조의 여러 가지 문제점을 극복하기 위해서도 매우 필요한 기법이라고 할 수 있다(Kim, 1995). 수치 과수조기법을 위한 경계치 문제 해석법으로는 고차경계요소법을 이용한 해석법이 가장 효율적인 것으로 알려져 있다. (중략)

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Measurement and Prediction of Long-term Deflection of Flat Plate Affected by Construction Load (시공하중에 의한 플랫 플레이트의 장기처짐 계측 및 해석)

  • Hwang, Hyeon-Jong;Park, Hong-Gun;Hong, Geon-Ho;Kim, Jae-Yo;Kim, Yong-Nam
    • Journal of the Korea Concrete Institute
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    • v.26 no.5
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    • pp.615-625
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    • 2014
  • Excessive long-term slab deflection caused by construction load is a critical issue for the design of concrete slabs, as long span flat plates become popular for tall buildings. In the present study, the effect of construction load causing early slab cracking on the long-term deflection was theoretically studied. On the basis of the result, a numerical analysis method was developed to predict the long-term deflection of flat plates. In the proposed method, immediate deflection due to slab cracking and long-term effect of creep and shrinkage were considered. To verify the construction load effect, long-term slab deflections were measured in actual flat plate buildings under construction. The results showed that the immediate deflection due to the construction load increased significantly the long-term deflection. The proposed method was used to predict the deflections of the buildings. The results were compared with the measurement results. The predictions agree well with the long-term deflections of flat plate affected by construction load.

The influence of dynamic force balance on the estimation of dynamic uniaxial compression strength (암석시료 내 동적하중 분배특성이 동적일축압축강도에 미치는 영향성에 관한 연구)

  • Oh, Se-Wook;Min, Gyeong-Jo;Park, Se-Woong;Park, Hoon;Suk, Chul-Gi;Cho, Sang-Ho
    • Explosives and Blasting
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    • v.37 no.1
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    • pp.14-23
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    • 2019
  • It has been an always issue for the blasting or the impact analysis to consider the strength characteristics of the rock materials associate with loading rate dependency. Due to the nature of transient loading, the dynamic rock test requires a careful technique to achieve the stress equilibrium state of the specimen. In this study, to investigate the relationship between the rock dynamic strength and the stress equilibrium state, a series of dynamic uniaxial compression tests for Pocheon granite were performed. As a result, the unbalanced stress state on the specimen can lead to the premature failure on the specimen and the less estimation of dynamic strength characteristic as well as the overestimation of strain rate. Consequently, a careful consideration of rock fracture process to achieve the dynamic force balance on the specimen should be required to make an reasonable evaluation of rock dynamic strength.

Study on Stress Variation in Slab and Support of Shearwall-Type RC Apartment during Construction (전단벽식 아파트에서 시공중 슬래브 및 동바리의 응력변화에 대한 연구)

  • Kim Young-Chan
    • Journal of the Korean Society of Safety
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    • v.19 no.4 s.68
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    • pp.161-165
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    • 2004
  • Safety and efficiency in the construction of RC structures mainly depends on optimal operation of shore-slat systems. The disasters in RC construction are mainly due to excessive load applied to falsework and premature removal of supports. Development of sufficient compressive strength of early-age connote is essential for the safety of structures during construction. Most of studies on shore-slab interaction have focused on flat slab structures. In this study, load distributions in floor slabs and supports during the construction of shear wall-type RC apartment building structures is investigated using finite element analysis.

Histomorphometry and Stability Analysis of Loaded Implants with two Different Surface Conditions in Beagle Dogs (하중을 가한 두 가지 표면의 임플란트에 관한 조직형태학적 분석 및 안정성 분석 (비글견을 이용한 연구))

  • Kim, Sang-Mi;Kim, Dae-Gon;Cho, Lee-Ra;Park, Chan-Jin
    • Journal of Dental Rehabilitation and Applied Science
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    • v.24 no.4
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    • pp.337-349
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    • 2008
  • Despite an improved bone reactions of Mg-incorporated implants in the animals, little yet has been carried out by the experimental investigations in functional loading conditions. This study investigated the clinical and histologic parameters of osseointegrated Mg-incorporated implants in delayed loading conditions. A total of 36 solid screw implants (diameter 3.75 mm, length 10mm) were placed in the mandibles of 6 beagle dogs. Test groups included 18 Mg-incorporated implants. Turned titanium Implants served as control. Gold crowns were inserted 3 months. Radiographic assessments and stabilitytests were performed at the time of fixture installation, $2^{nd}$ stage surgery, 1 and 3 months after loading. Histological observations and morphometrical measurements were also performed. Of 36 implants, 32 displayed no discernible mobility, corresponding to successful clinical function. There was no statistically significant difference between test implants and controls in marginal bone levels (p=0.413) and RFA values. The mean BIC % in the Mg-implants was $54.4{\pm}20.2%$. The mean BIC % in the turned implant was $48.9{\pm}8.0%$. These differences between the Mg-implant and control implant were not statistically significant (P=0.264). In the limitation of this study, bone-to-implant contact (BIC) and bone area of Mg-incorporated oxidized implant were similar to machine-turned implant. The stability analysis showed no significantly different ISQ values and marginal bone loss between two groups. Considering time-dependent bone responses of Mg-implant, it seems that Mg-implants enhanced bone responses in early loading conditions and osseointegrated similarly to cp Ti implants in delayed loading conditions. However, further investigations are necessary to obtain long-term bone response of the Mg-implant in human.