• Title/Summary/Keyword: anchorage system

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Strengthening Evaluation of Post-Tensioning Due to Anchorage System (정착방법에 따른 외부 프리스트레이트 도입공법의 보강성능 평가)

  • 박승범;홍석주
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.04a
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    • pp.279-284
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    • 2000
  • The bridge is nation's principal structure and its influence for national economy is enormous. But it is essential for maintenance of deteriorated bridge because of the increased service life and the decreased performance. For the bridge reinforced by continuos slabs and post-tensioning, we evaluate th stress properties of girders and internal support. Results are almost coincidence between measured data in the field and analysed data by computer. We compared the effects by successive order of post- tensioning and order considered distribution of each girder's camber and stress. Bridge's camber and stress showed respectively symmetry and asymmetry shape by post tensioning order. For the effect of post-tensioning force partition, we divided the post-tensioning force into 3 types (100%, 20%, 30%), and the results show t도 difference of final stress and camber.

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A Study on the Evaluation of Tensile Performance According to Pareral Jointing Methods of the Sheet Membrane Waterproofing System (방수시트의 평행접합방법에 따른 인장성능 평가연구)

  • Lee Jeoung-Yun;Oh Mi-Hyun;Kwak Kyu-Sung;Oh Sang-Keun
    • Proceedings of the Korean Institute of Building Construction Conference
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    • v.y2004m10
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    • pp.39-44
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    • 2004
  • A heat and room temperature construction method of asphalt have been mainly applying to rooftop waterproofing in concrete structure, and the rest construction method are sheet, membrane and mortar waterproofing construction method. In particular, joint method in sheet waterproof method is as overlap joint which on being reinforced with fiber and tape, have been applying for job site to mechanical fix using protection disk and anchorage and metal ironwork on the end of sheet. These construction method cause cutting off joint of sheet as behavior of structure according to repairs of sheet itself and thermal conduct, outdoor air environment. In conclusion, we analyzed and examined the application of various sheets and piece ashes about superior 'I' joint which divide from one and the other sheet and progressed about joint construction method of fixing method for overlap.

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A neuro-fuzzy approach to predict the shear contribution of end-anchored FRP U-jackets

  • Kar, Swapnasarit;Biswal, K.C.
    • Computers and Concrete
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    • v.26 no.5
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    • pp.397-409
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    • 2020
  • The current study targets to estimate the contribution of the end-anchored FRP composites in resisting shear force using a soft computing tool i.e., adaptive neuro-fuzzy inference system (ANFIS). A total of 107 sets of data accumulated from literature was utilized for the development and evaluation of the current ANFIS model. A comparative analysis between the ANFIS predictions and the acquired experimental results has shown that the ANFIS predictions are in very good agreement with that of experimental ones. Additionally, the accuracy of the current ANFIS model has been weighed up against the estimates of nine widely adopted design guidelines. Based on various statistical parameters, it has been deduced that the effectiveness of the current ANFIS model is better than the considered design guidelines. Besides this, a parametric study was carried out to explore the combined effect of different parameters as well as the impact of individual parameters.

Corticotomy for orthodontic tooth movement

  • Lee, Won
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.44 no.6
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    • pp.251-258
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    • 2018
  • Corticotomy was introduced as a surgical procedure to shorten orthodontic treatment time. Corticotomy removes the cortical bone that strongly resists orthodontic force in the jaw and keeps the marrow bone to maintain blood circulation and continuity of bone tissues to reduce risk of necrosis and facilitate tooth movement. In the 21st century, the concept of regional acceleratory phenomenon was introduced and the development of the skeletal anchorage system using screw and plate enabled application of orthopedic force beyond conventional orthodontic force, so corticotomy has been applied to more cases. Also, various modified methods of minimally invasive techniques have been introduced to reduce the patient's discomfort due to surgical intervention and complications after surgery. We will review the history of corticotomy, its mechanism of action, and various modified procedures and indications.

Performance assessment of multi-hazard resistance of Smart Outrigger Damper System (스마트 아웃리거 댐퍼시스템의 멀티해저드 저항성능평가)

  • Kim, Hyun-Su
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.19 no.5
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    • pp.139-145
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    • 2018
  • An outrigger system is used widely to increase the lateral stiffness of high-rise buildings, resulting in reduced dynamic responses to seismic or wind loads. Because the dynamic characteristics of earthquake or wind loads are quite different, a smart vibration control system associated with an outrigger system can be used effectively for both seismic and wind excitation. In this study, an adaptive smart structural control system based on an outrigger damper system was investigated for the response reduction of multi-hazards, including seismic and wind loads. A MR damper was employed to develop the smart outrigger damper system. Three cities in the U.S., L.A., Charleston, and Anchorage, were used to generate multi-hazard earthquake and wind loads. Parametric studies on the MR damper capacity were performed to investigate the optimal design of the smart outrigger damper system. A smart control algorithm was developed using a fuzzy controller optimized by a genetic algorithm. The analytical results showed that an adaptive smart structural control system based on an outrigger damper system can provide good control performance for multi-hazards of earthquake and wind loads.

A Study on the Navigational Conditions in the Ulsan Approaching Waters (울산항의 항행환경 조사.분석)

  • Jeong, Jae-Yong;Kim, Cheol-Seung;Park, Young-Soo;Jeong, Ki-Nam
    • Journal of the Korean Society of Marine Environment & Safety
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    • v.14 no.3
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    • pp.211-217
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    • 2008
  • Natural environment, topographical conditions and marine traffic flows were investigated and questionnaire surveys were performed for the purpose of understanding the cause of marine accidents. The frequent cases of ships' dragging have happened at the anchorages of E-1, E-2 and E-3. The anchorage area is insufficient for the accommodation of a number of ships, the dolphins at the nearby piers are located near a narrow fairway. SBMs' are positioned too close to the fairway. It shows that many crossing marine traffic flows occur in all areas of the port. Marine casualties are concentrated mainly at No. 1 fairway, M1-M7 waters close to the dolphins and Gwanjeolgot, "E" anchorage and the waters close to the fairway "come and go" areas. The marine traffic flow is mainly caused by the ships' movement at the inter-port and most of the ships are the dangerous cargo carriers. And small ships like the tug-barge are moving disorderly in the ports. Furthermore, the fairway‘s layout is crossing each other. Questionnaire surveys of the users and experts shows that the LANBY that can distinguish the fairway of "come and go" ports is required.

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Novel Alternative Methods in Toxicity Testing

  • Satoh, Tetsuo
    • Proceedings of the Korean Society of Applied Pharmacology
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    • 1994.04a
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    • pp.129-130
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    • 1994
  • The science of toxicology is the understanding of the mechanisms by which exogenous agents produce deleterious effects in biological systems. The actions of chemicals such as drugs are ultimately exerted at the cellular and gene levels. Over the past decade. several in vitro alternative methods such as cultured cells for assessing the toxicity of various xenobiotics have been proposed to reduce the use of animals. In this workshop three advanced methods will be presented. These methods are novel important models for toxicologic studies. Dr. Tabuchis group has establishcd two immortalized gastric surface mucosa cell lines from the pminary cultore of gastric fundic mucosal cells of adult transgenic mice harboring a temperature sensitive simian virus 40 large T-anugen gene. As the immortalized cell lines of various tissues possess unique characteristics to maintain their normal functions for several months, these cell lines are extremely useful for not only toxicity testing but also pharmacological screening in new drug development. Professor Funatsu have studied the formation of spherical multicelluar aggregates of adult rat hepatocytes(spheroid) having tissue like structure. The sphcroid shown thre is a prototype module of an artificial liver support system. Thus, the urea synthesis activity of the artificial liver was maintained at least to days in 100% rat blood plasma. Dr. Takezawa and his coworkers have developed a novel culture system of multicellular spheroids considered 〃organoids〃 by utilizing a thermo-responsive polymer as a substratum of anchorage dependent cells. His final goal is to reconstitute the organoids of various normal organs, e.g., liver, skin etc. and also abnormal deseased organs such as tumor.

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DEFORMATION OF AUGUSTINE VOLCANO, ALASKA, 1992-2006, MEASURED BY ERS AND ENVISAT SAR INTERFEROMETRY

  • Lee, Chang-Wook;Lu, Zhong;Kwoun, Oh-Ig
    • Proceedings of the KSRS Conference
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    • v.2
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    • pp.582-585
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    • 2006
  • Augustine volcano is an active stratovolcano located southwest of Anchorage, Alaska. Augustine volcano experienced seven significantly explosive eruptions in 1812, 1883, 1908, 1935, 1963, 1976, and 1986, and a minor eruption in January 2006. To measure ground surface deformation of Augustine volcano, we applied satellite radar interferometry with ERS-1/2 and ENVISAT SAR images acquired from three descending and three ascending satellite tracks. Multiple interferograms are stacked to reduce artifacts due to changes in atmospheric condition and retrieve temporal deformation sequence. For this, we used Least Square (LS) method for reducing atmospheric effects and Singular Value Decomposition (SVD) method for the retrieval of a temporal deformation sequence. Interferograms before 2006 eruption show about 3 cm/year subsidence by contraction of pyroclastic flow deposits from the 1986 eruption. Interferograms during 2006 eruption do not show significant deformation around volcano crater. Interferograms after 2006 eruption show again a several cm subsidence by compaction and contraction of pyroclastic flow deposits for a few months. This study demonstrates that satellite radar interferometry can monitor deformation of Augustine volcano to help understand the magma plumbing system driving surface deformation.

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A Study on Design Methods and the Composition Elements in Flexure Structure Systems (휨 구조시스템의 구조디자인적 구성요소와 디자인 조합 수법 분석)

  • Lee, Juna
    • Journal of Korean Association for Spatial Structures
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    • v.16 no.1
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    • pp.73-84
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    • 2016
  • This study analyzes the four composition elements : profile, anchorage and connection, material and member rigidity, stability, as the main composition design elements of flexure structure systems, in order to explore possibilities for more various structure designs in architectures with flexure structure system. It also examines typical design methods that use the mentioned four composition elements. At the results, this research presents an understanding of the differences between funicular shape and non-funicular shape and mechanical features of the shapes in the profile element, regarding to the ratio of rise height to span length(f/l). Also, the typical design methods are presented for the designable usages of the hinge joints and the fix joints, and for the applications of member rigidity expressed by the index of the ratio of member depth to span length(d/l). And it was presented that connection styles, addition of brace members, placement of shear walls are the main design methods in the stability element. This data would be useful to architectural designs concerning integrated design with structures.

The Optimal Shape Design for the Compression Joint of Thermal Bridge Breaker using FEM (유한요소 해석을 통한 열교 차단장치의 압축판 최적형상 설계)

  • Shin, Dong-Hyeon;Kim, Young-Ho;Kim, Hyung-Joon
    • Journal of The Korean Digital Architecture Interior Association
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    • v.13 no.2
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    • pp.17-25
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    • 2013
  • It is important to eliminate thermal bridge for achieving passive and environmental-friendly buildings. Structural members may frequently act as thermal bridges that become a conduit of energy. it is emphasized that thermal bridge breaker (TBB) system is necessary for blocking thermal bridge of the structural members. This TBB system has to maintain a performance to tensile and compressive stress which arises in member section in order to being realized structurally. Thus, it is composed with anchorage devices which obtain continuity with structural members inside building and rebar of cantilever balcony, and compression joint which resist compression stress occurring to TBB. Applying method of TBB's compression joint is designed to have high strength with comparatively small element section which can cover external load. This study carried out finite elements method based on compression experiment. Throughout the FEM analysis, this study provides information on finding optimal shape for compression joint of TBB which can suitably apply to current building balcony of Korea.