• Title/Summary/Keyword: solid elements

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The Scope of English Education as an Academic Discipline (영어교육학의 학문적 성격과 연구 범위)

  • 이흥수
    • Korean Journal of English Language and Linguistics
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    • v.3 no.1
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    • pp.133-155
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    • 2003
  • The purpose of this paper is to survey the definition and scope of English Education as an academic discipline or science, relating to English linguistics, linguistics and applied linguistics. English Education has come to be regarded as fulfilling its true function when it is based on the solid scientific principles and methods of such related sciences as linguistics, English linguistics, psycholinguistics, sociolinguistics, sociology, psychology and pedagogy. English Education is, therefore, an independent and specialized applied science, interrelated with the sciences mentioned above. Thus, English Education is defined as an academic discipline which is concerned with the concrete teaching and learning of English, and which is based on the scientific methods, applications and evaluations of English. As a science, English Education has three elements: content, process and methods. Content, which concerns input, consists of the fundamental interrelated sciences and English language skills. Process refers to research methodology and analysis. Methods are the application of the theories and the processes.

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Nondestructive Contactless Sensing of Concrete Structures using Air-coupled Sensors

  • Shin, Sung-Woo;Hall, Kerry S.;Popovics, John S.
    • International Journal of Safety
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    • v.7 no.2
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    • pp.17-22
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    • 2008
  • Recent developments in contactless, air-coupled sensing of seismic and ultrasonic waves in concrete structures are presented. Contactless sensing allows for rapid, efficient and consistent data collection over a large volume of material. Two inspection applications are discussed: air-coupled impact-echo scanning of concrete structures using seismically generated waves, and air-coupled imaging of internal damages in concrete using ultrasonic tomography. The first application aims to locate and characterize shallow delamination defects within concrete bridge decks. Impact-echo method is applied to scan defected concrete slabs using air coupled sensors. Next, efforts to apply air-coupled ultrasonic tomography to concrete damage imaging are discussed. Preliminary results are presented for air-coupled ultrasonic tomography applied to solid elements to locate internal defects. The results demonstrate that, with continued development, air-coupled ultrasonic tomography may provide improved evaluation of unseen material defects within structures.

The Finite Element Analysis of Car Seat Frame According to The FMVSS Strength Test (FMVSS 강도테스트에 다른 자동차 시트프레임의 유한요소해석)

  • 이호용;임중연;범형택
    • Transactions of the Korean Society of Automotive Engineers
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    • v.7 no.6
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    • pp.241-247
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    • 1999
  • This study presents the structural analysis of car a seat frame by the finite element method. The load-deformation characteristics of seat frame are simulated according to the test requirements by FMVSS. Three dimensional modeling technique is applied to the components of the seat frame. The shell, solid , gap and rigid elements are employed to model the car seat frame assembly. Numerical results show that the recliner and kunckle plate are identified as the possible weak part of frame, and the results are well consistent with the experimental static load test. The current analysis model can provide useful informations to design a new car seat and can reduce the overall design cost and time.

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Analysis of Elements Influencing on Performance of Interior Ballistics (강내탄도의 성능 영향 요소 분석)

  • Sung, Hyung-Gun;Yoo, Seung-Young;Choi, Dong-Whan;Roh, Tae-Seong
    • Proceedings of the Korean Society of Propulsion Engineers Conference
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    • 2011.11a
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    • pp.228-236
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    • 2011
  • The analysis of the performance and the internal flow according to various numerical models used for the interior ballistics has been conducted. The internal flow has been mainly affected by the drag model. As results, oscillations of the pressure differences between the breech and the shot base has been reduced with a deceased drag of the propellant. The major performance of the interior ballistics has no relation to the models using Nusselt number for heat transfer coefficient. The negative pressure difference without the heat transfer of the propellant has not been shown.

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Studies into a high performance composite connection for high-rise buildings

  • Lou, G.B.;Wang, A.J.
    • Steel and Composite Structures
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    • v.19 no.4
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    • pp.789-809
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    • 2015
  • This paper presents experimental and numerical studies into the structural behavior of a high performance corbel type composite connection adopted in Raffles City of Hangzhou, China. Physical tests under both monotonic and quasi-static cyclic loads were conducted to investigate the load carrying capacities and deformation characteristics of this new type of composite connection. A variety of structural responses are examined in detail, including load-deformation characteristics, the development of sectional direct and shear strains, and the history of cumulative plastic deformation and energy. A three-dimensional finite element model built up with solid elements was also proposed for the verification against test results. The studies demonstrate the high rigidity, strength and rotation capacities of the corbel type composite connections, and give detailed structural understanding for engineering design and practice. Structural engineers are encouraged to adopt the proposed corbel type composite connections in mega high-rise buildings to achieve an economical and buildable and architectural friendly engineering solution.

Elastic Modulus Measurement of a Dry Process Fuel Pellet by Resonant Ultrasound Spectroscopy (초음파 공진 분석법을 이용한 건식공정 핵연료 소결체의 탄성계수 측정)

  • 류호진;강권호;문제선;송기찬;정현규;정용무
    • Journal of Powder Materials
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    • v.11 no.4
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    • pp.314-321
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    • 2004
  • The elastic moduli of simulated dry process fuels with varying composition and density were measured in order to analyze the mechanical properties of a dry process fuel pellet. Resonant ultrasound spectroscopy(RUS) which can determine all elastic moduli with one set of measurements for a rectangular parallelepiped sample was used to measure the elastic moduli of UO$_{2}$ and simulated dry process fuel. The simulated dry process fuel showed a higher value of Young's modulus than UO$_2$ due to the presence of metallic precipitates and solid solution elements in the UO$_{2}$ matrix. The correlation between Young's modulus and porosity(P) of simulated dry process fuel was found to be 231.4-651.8 P (GPa) at room temperature. Dry process fuel with a higher burnup showed higher Young's modulus because total content of fission product element was increased.

Experiments and Prediction of Pitting Life in Spur Gears (스퍼기어의 피팅 수명 예측 및 실험)

  • Kim, Jong-Sung;Ju, Jin-Wook;Lee, Sang-Don;Cho, Yong-Joo
    • Tribology and Lubricants
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    • v.25 no.6
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    • pp.399-403
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    • 2009
  • The objective of this paper is to predict pitting initiation by using a contact analysis and subsurface stress. Contact stresses are obtained by contact analysis of a semi-infinite solid based on the use of influence functions. Subsurface stress field is obtained using rectangular patch solutions. It is used Mesoscopic multiaxial fatigue criterion to predict contact fatigue life. It is important to predict pitting initiation to enhance reliability of the mechanical elements. Pitting life prediction in the spur gears which are fundamental mechanical element is presented in this paper.

Die design for HIP'ing of Nickel-base Superalloys (초내열합금 HIP 성형을 위한 금형설계)

  • Lim J.S.;Yeom J.T.;Hou Bongliang;Park N.K.
    • Proceedings of the Korean Society for Technology of Plasticity Conference
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    • 2004.05a
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    • pp.139-142
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    • 2004
  • Nickel base superalloys are widely used for high temperature applications due to heat resisting capability and corrosion resistance at high temperatures. Superalloys with many strengthening alloying elements are frequently used in powder form to alleviate harmful effects of alloy segregation. HIP (hot isostatic pressing) and DB (diffusion bonding) as a form of solid-state bonding process is used to make turbine components, such as integrated turbine rotors. HIP/DB process requires many technical overcomes related to dimensional changes as well as microstructural control. In this research, HIP/DB process for nickel base superalloys, Udimet 720 and MM 247, were investigated with a view to control the dimensional change during the consolidation process. Simple disc-shaped cans were used to select the conceptual die design for the control of the dimensional change especially in radial direction. The change in the shape of consolidated shape was investigated using commercial FE code with constitutive equations fur low temperature plasticity deformation.

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Modeling of Groundwater Flow Using the Element-Free Galerkin (EFG) Method

  • Park, Yu-Chul;Darrel I. Leap
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2001.04a
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    • pp.77-80
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    • 2001
  • The element-free Galerkin (EFG) method is one of meshless methods, which is an efficient method of modeling problems of fluid or solid mechanics with complex boundary shapes and large changes in boundary conditions. This paper discusses the theory of the EFG method and its applications to modeling of groundwater flow. In the EFG method, shape functions are constructed based on the moving least square (MLS) approximation, which requires only set of nodes. The EFG method can eliminate time-consuming mesh generation procedure with irregular shaped boundaries because it does not require any elements. The coupled EFG-FEM technique was introduced to treat Dirichlet boundary conditions. A computer code EFGG was developed and tested for the problems of steady-state and transient groundwater flow in homogeneous or heterogeneous aquifers. The accuracy of solutions by the EFG method was similar to that by the FEM. The EFG method has the advantages in convenient node generation and flexible boundary condition implementation.

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A study on the long-term behavior due to the hydraulic interaction between ground water and tunnel (지하수-터널 수리상호작용에 따른 터널의 장기거동 연구)

  • Shin, Jong-Ho;Shin, Yong-Suk;Ahn, Sang-Ro;Park, Dong-In
    • Proceedings of the Korean Geotechical Society Conference
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    • 2006.03a
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    • pp.239-248
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    • 2006
  • The interaction between ground water and structure is complicated behavior which cannot be easily investigated In the laboratory and monitored in the fields. In this study numerical simulation of the interactive behavior was performed using sophisticated coupled-finite element method. Hydraulic behavior of structure is modeled using solid elements with finite Permeability. Recovery of ground water table in the long-term is considered by controlling hydraulic boundary conditions. The results showed that the interaction effect is significant. Particularly non-symmetry in the lining permeability resulted in highly unbalanced pore water pressure which may cause detrimental effects on inner linings of tunnels acting as drains.

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