• Title/Summary/Keyword: track tension

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Design and evaluation of renovated NSI T/O PC sleeper (개량형 NSI 분기기용 PC침목 설계와 성능평가)

  • Park, Choon-Bok;Kwon, Ho-Jin;Lee, Young-Sou;Yoon, Byung-Hyun;Shin, Won-Sun
    • Proceedings of the KSR Conference
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    • 2007.05a
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    • pp.1129-1137
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    • 2007
  • 50kg NSI PCT(Prestress Concrete Timber, sleeper) is developed for the purpose of low maintenance cost, Extend life cycle, Track stability, Friendly Environment, Good running quality. In this study, as a part of research which is to make renovated NSI turnout, the main objective of this study is the optimization of PC sleeper's section, the number of PS tension wire. For this purpose, the finite element analysis was conducted to evaluate the serviceability and the safety of NSI PC sleeper developed.

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Composite Graft Reconstruction of Esophagus for Double Primary Cancer of Larynx & Esophagus (후두암과 식도암의 이증원발성 종양에서의 합이식술을 이용한 식도 재건술)

  • I Hoseok;Song Dong Seop;Kim Su Wan;Shim Young Mog
    • Journal of Chest Surgery
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    • v.38 no.11 s.256
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    • pp.791-794
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    • 2005
  • After esophagectomy, the stomach is used most commonly for the method of reconstruction. However, the stomach may not be large enough to be reached the site of anastomosis when it is above the pharynx. We experienced a double primary cancer of the lower esophagus and the larynx. Total laryngectomy and total esophagectomy were done with cervical pharyngojejunogastrostomy for reconstruction. Free jejunal graft is interposed between the oropharyngeal stump and the stomach is pulled-up. We could restore the alimentary track without tension at the anastomotic site and obtain sufficient blood supply.

A Study on the tension of Geogid on Pile-supported Construction Method (성토지지말뚝공법 중 섬유보강재의 인장력 검토에 관한 연구)

  • Moon, In-Ho;Park, Jong-Gwan;Lee, Il-Wha
    • Proceedings of the KSR Conference
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    • 2008.11b
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    • pp.905-917
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    • 2008
  • Road or Railway construction over soft ground is needed to be considered on secondary consolidation which will be caused differential settlement, lack of transport serviceability, higher maintenance cost. Especially for the railway construction in the second phase of Gyung-Bu or Ho-Nam high speed railway, concrete slab track has been adapted as a safe and cost effective geotechnical solution. In this case controlling the total settlement under the tolerance is essential. And pile supported geogrid reinforced construction method is suggested as a solution for the problem of the traditional method on soft soil treatments. Pile supported geogrid reinforced construction method consists of piles that are designed to transfer the load of the embankment through the compressible soil layer to a firm foundation. The load from the embankment must be effectively transferred to the piles to prevent punching of the piles through the embankment fill creating differential settlement at the surface of the embankment. The arrangement of the piles can create soil arching to carry the load of embankment to the piles. In order to minimize the number of piles geogrid reinforced pile supported construction method is being used on a regular basis. This method consists of one or more layers of geogrid reinforcement placed between the top of the piles and the bottom of the embankment. This paper presents several methods of pile supported geogrid reinforced construction and calculation results from the several methods and comparison of them.

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Inverse analysis of erection process for prismatic tensegrity structures with redundant cables

  • Pei Zhang;Huiting Xiong;Jingjing Yang;Jiayan Liu
    • Steel and Composite Structures
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    • v.49 no.2
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    • pp.125-141
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    • 2023
  • Firstly, a new kind of prismatic tensegrity structures with redundant cables is defined, the topology, geometry and forming conditions of which are introduced further. The development of its mechanical properties including self-stress states and structural stiffness with the increment of the twist angle is also investigated carefully. Combined with the topology of this kind of structures, a reasonable erection scheme is proposed, in which some temporary lifting points need to be set and two groups of vertical cables are tensioned in batches. Then, a simplified dynamic relaxation method is employed to track the erection process inversely, which aims to predict each intermediate equilibrium state during the construction, and give the key structural parameters that can effectively guide the construction. The removal of the active cables, the relaxation or tension of the passive cables are simulated by controlling their axial stiffness, so that the structural composition as well as the serial numbers of the elements always keep invariant regardless of the withdrawal of the slack cables. The whole analysis process is clear in concept, simple to implement and easy to popularize. Finally, several examples are given to verify the practicability and effectiveness of the proposed method further.

Real-scale Accelerated Testing to Evaluate Long-term Performance for Bridge/Earthwork Transition Structure Reinforced by Geosynthetics and Cement Treated Materials (토목섬유와 시멘트처리채움재로 보강한 교량/토공 접속구조의 장기공용성 평가를 위한 실물가속시험)

  • Lee, Il-Wha;Choi, Won-Il;Cho, Kook-Hwan;Lee, Kang-Myung;Min, Kyung-Chan
    • Journal of the Korean Society for Railway
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    • v.17 no.4
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    • pp.251-259
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    • 2014
  • The transition zone between an earthwork and a bridge effect to the vehicle's running stability because support stiffness of the roadbed is suddenly changed. The design criteria for the transition structure on ballast track were not particular in the past. However with the introduction of concrete track is introduced, it requires there is a higher performance level required because of maintenance and running stability. In this present paper, a transition structure reinforced with geosynthetics is suggested to improve the performance of existing bridge-earthwork transition structures. The suggested transition structure, in which there is reinforcing of the approach block using high-tension geosynthetics, has a structure similar to that of earth reinforced abutments. The utilized backfill materials are cement treated soil and gravel. These materials are used to reduce water intrusion into the approach block and to increase the recycling of surplus earth materials. An experiment was performed under the same conditions in order to allow a comparison of this new structure with the existing transition structure. Evaluation items are elastic displacement, cumulative settlement, and earth pressure. As for the results of the real-scale accelerated testing, the suggested transition structure has excellent performance for the reduction of earth pressure and settlement. Above all, it has high resistance the variation of the water content.

Robotic String Musical Instrument as an Interactive Game Prototype (체감형 게임 원형으로서의 로봇 현악기 설치미술)

  • Kim, Tae-Hee
    • Journal of Korea Game Society
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    • v.12 no.1
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    • pp.57-65
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    • 2012
  • Interactive games allow users to obtain embodied experience using the bodies as controllers. The same is true in interactive media arts where users engage in active participation. In contrast to video games, physical body feedback is desired and such practice can be found in robotic arts. I suggest that interactive media arts and interactive games should share common foundations. In this context, I introduce and explain an interactive robotic art work implemented. This work is a musical instrument that employs a robot which travels sitting on two strings in response to audience positions. In results, the robot modulates the vibrations of the strings by causing the effective lengths of the strings changed. The robot uses an economic multi-cell proximity sensor in order to track the audience. In the interaction, phenomenological tension could take place in the performative narrative space. In this paper, I discuss this interactive robotic work in the context of interactive games with a few examples.

Feasibility Study on the Two-dimensional Free Surface Simulation Using the Lattice-Boltzmann Method (Lattice Boltzmann Method를 이용한 2차원 자유수면 시뮬레이션 기법연구)

  • Jung, Rho-Taek
    • Journal of the Korean Society for Marine Environment & Energy
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    • v.15 no.4
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    • pp.273-280
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    • 2012
  • The numerical simulation using the Lattice Boltzmann Method in the field of computational fluid dynamics becomes wider in the engineering applications because of its simplicity of update rules compared to the conventional Navier-Stokes solvers. Here, a two-dimensional D2Q9 LB model is numerically tested with a few new computational treatment on the free surface. The single relaxation time is applied under the gravitational field where applied only in the higher density fluid because of its big density difference. At the free surface, the reconstruction techniques in combination with boundary conditions is adopted in order to get some distribution function coming into the fluid site from the air one, and surface tension, early stable test for the gravitional field is considered in it. With the implementation of the gravitational profile, conserving the overall mass and grid dependency are observed during the calculations and freesurface advance track is well captured with an experiment.

Evaluation of Ductility Capacity of Reinforced Concrete Bridge Columns Subject to Cyclic Loading Using Flexibility-Based Fiber Element Method (유연도법 섬유요소모델에 의한 반복하중을 받는 철근콘크리트 교각의 연성능력 평가)

  • 고현무;조근희;조호현
    • Journal of the Earthquake Engineering Society of Korea
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    • v.6 no.3
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    • pp.11-21
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    • 2002
  • The evaluation of displacement ductility is performed by direct method through tracking the inelastic hysteretic behavior of RC bridge columns subject to cyclic loading using a flexibility-based fiber element mode. To reasonably track the inelastic behavior until the RC bridge column reaches its ultimate state, the average stress-average strain relations and joint elements, which agree well with experiments, are modified and applied considering the tension stiffening behavior and discontinuous displacement between the column and its base. In addition the evaluation of displacement ductility is performed by a direct method easily applicable to numerical analysis. Locations for the integration points, values for the post-crushing concrete strength and low-cycle fatigue failure of longitudinal reinforcement that affect the calculation of yielding and ultimate displacements are proposed for the application to flexibility-based fiber element model. Since less than 10% of error occurs during the displacement ductility analysis, the yielding and ultimate displacements evaluated by the applied analysis method and model appear to be valid.

A Development of Detail Design Software for Conventional Catenary System (기존선 전차선로 상세설계 소프트웨어 개발)

  • Lee, Ki-Won;Kwon, Sam-Young;Cho, YongHyeon;Lee, Tae-Kwon;Lee, Kyung-Hoon
    • Proceedings of the KSR Conference
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    • 2008.06a
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    • pp.481-488
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    • 2008
  • A detail design of overhead catenary system can be divided into a pegging plan and a design of MD(mounting diagram). In the pegging plan, the mast location, staggering and tension length are determined in the longitudinal point of view according to track condition, location of substation and etc. In the MD, a transversal diagram including masts, all of wires, cantilever, foundation and etc. and materials used are shown. This study presents a development of a software to design the MD for a conventional catenary system automatically. In the program, thin walled steel pole, foundation, cantilever, all of wires and etc. are automatically drawn according to the input and catenary conditions. And materials used in the MD and the section can be also managed respectively in the program. This application of the program is developed using C# for input/calculating and using C++(ObjectARX) for drafting the MD, respectively.

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Applicability of the Pile-Supported Embankment in Korea (성토지지말뚝공법의 국내 적용성 분석)

  • Lee, Il-Wha;Kim, Seung-Sun;Lee, Joo-Gong;Shim, Shung-Kyu;Lee, Su-Hyung
    • Journal of the Korean Geotechnical Society
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    • v.32 no.3
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    • pp.5-13
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    • 2016
  • Stability analysis was conducted to analyze the application of pile-supported embankment to concrete slab track on the soft ground in Korea. Pile efficiency and tension of geosynthetics in accordance with the hight of embankment and the depth of soft soil were carried out by theoretical and numerical methods. Theoretical method predicted more conservatively than the numerical method for all the cases presented herein. The settlement stability is satisfied to allowable criteria of high speed railway in Korea. The pile-supported embankment has great potential for application to soft ground condition.