• Title/Summary/Keyword: Dynamic assessment

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The assessment of tumoral necrosis in rat tumor model using dynamic T1/T2* gradient dual echo sequence with Gd-DTPA and Gadomer-17 as a MR contrast agent

  • 허용민;김대홍;김은주;송호택;서진석;이상훈
    • Proceedings of the KSMRM Conference
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    • 2003.10a
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    • pp.93-93
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    • 2003
  • To test the feasibility of rBF and rBVin the assessment of R004 sarcomas of the rat and to compare the results obtained by using Gd-DTPA and Gadomer-17 as a MR contrast agent, on the basis of the histological findings of tumor necrosis.

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Construction of Environmental Fate Model for Risk Assessment

  • Park, Shinai;Jeeyeun Han;Park, Jongsei
    • Proceedings of the Korean Society of Toxicology Conference
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    • 2002.11b
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    • pp.197-197
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    • 2002
  • In terms of the risk assessment, qualitative and quantitative informations are needed to estimate the exposures of environmental pollutants, which may create risks, and those are the information according to the changes caused by the movement of substances from the pollutant and duration.(omitted)

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Assessment of Reliability and Load Carrying Capacity of Aged Wharf Structure of Pier Type (노후된 잔교식 부두의 신뢰성 및 내하력 평가)

  • 조효남;김성훈;김종규;이승재;최영민
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1994.10a
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    • pp.71-78
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    • 1994
  • The main objectives of the study may be stated as follows : \circled1 the acquisition of fundamental updated data for the assessment of aged wharf structures of pier type based on systematic static/dynamic load testing \circled2 the study of techniques and methods for field testing \circled3 realistic safety and load carrying capacity assessment based on practical reliability analysis. In this study field testing of real structure is performed and the results are compared with those of the 2D and 3D linear structural analysis. It may be seen that the practical reliability methods can be applied for the safety and capacity assessment of aged wharf structures of pier type.

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Proof Load Test and Integrity Assessment of Segmental PC Box-girder Bridges (Segmental PC 박스거더교의 검증재하시험 및 건전성평가)

  • 조효남;임종권;옥승범;지광습
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.132-141
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    • 1995
  • This study is intended to propose practical but systematic and rational approaches for proof load test and integrity assessment of segmental PC box-girder bridges. The proposed models cover the whole range of field tests and assessment of such as inspections, nondestructive tests, static and dynamic load tests, structural analysis, and integrity assessment for the evaluation of load carrying capacity, serviceability, and durability of PC box-girder bridges. They are applied to a newly constructed precast segmental PC box-girder bridge which is a part of the Seoul interior circuit elevated expressway.

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An Analytical Investigation of the Characteristics of Four-Nozzle Flapper Valve (4-노즐 플렙퍼 밸브 특성에 대한 해석적 고찰)

  • 이재천
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2001.04a
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    • pp.161-166
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    • 2001
  • The static characteristics of four-nozzle flapper valves are investigated with both constant flow and constant supply pressure. The ranges, in which linearization of these characteristics would be valid, are discussed. Linearized dynamic model is also derived. Numerical simulations of nonlinear dynamic model are carried out by HyPneu to make an assessment of the effect of input step size in both cases of no-load and blocked-load operation.

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Load Test and Remote Monitoring of P.C. Box Girder Bridge (P.C. BOX 교량의 재하시험 및 원격계측 유지관리 시스템)

  • Lee, Sung-Woo;Doobyong Bae;Lee, Sun-Goo
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1995.10a
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    • pp.122-131
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    • 1995
  • Load test for newly introduced precast segmental bridge is carried out to experimentally evaluate load carrying capacity, Analysis accompanied with the test is also performed and the results are used in the evaluation. In addition to initial evaluation of the bridge by load test, remote dynamic monitoring system to perform realtime assessment of the bridge condition is also under development. In this paper the procedure and results of load test and evaluation are presented along with introduction of dynamic monitoring system.

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Dynamic and static structural displacement measurement using backscattering DC coupled radar

  • Guan, Shanyue;Rice, Jennifer A.;Li, Changzhi;Li, Yiran;Wang, Guochao
    • Smart Structures and Systems
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    • v.16 no.3
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    • pp.521-535
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    • 2015
  • Vibration-based monitoring is one approach used to perform structural condition assessment. By measuring structural response, such as displacement, dynamic characteristics of a structure may be estimated. Often, the primary dynamic responses in civil structures are below 5 Hz, making accurate low frequency measurement critical for successful dynamic characterization. In addition, static deflection measurements are useful for structural capacity and load rating assessments. This paper presents a DC coupled continuous wave radar to accurately detect both dynamic and static displacement. This low-cost radar sensor provides displacement measurements within a compact, wireless unit appropriate for a range of structural monitoring applications. The hardware components and operating mechanism of the radar are introduced and a series of laboratory experiments are presented to assess the performance characteristics of the radar. The laboratory and field experiments investigate the effect of factors such as target distance, motion amplitude, and motion frequency on the radar's measurement accuracy. The results demonstrate that the radar is capable of both static and dynamic displacement measurements with sub-millimeter accuracy, making it a promising technology for structural health monitoring.

The effect of CFRP-concrete bond mechanism on dynamic parameters of repaired concrete girders

  • Fayyadh, Moatasem M.;Razak, Hashim A.
    • Structural Engineering and Mechanics
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    • v.82 no.3
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    • pp.343-354
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    • 2022
  • An understanding of the mechanism of concrete girders repaired with CFRP plates and its influence on the dynamic parameters is presented in this paper. Dynamic parameters are governed by the relationship with the physical properties of concrete girders and CFRP plates as well as the adhesive layer between them. A brief explanation of the mechanism of the composite action of concrete girders repaired with CFRP is also given in this paper. Experimental work was carried out to validate the theory of the composite action. The results show a decrease in the modal parameters of CFRP repaired girders that were turned over during the repair procedure, which contrasts with the proven static-based results that CFRP plates increase the stiffness of repaired girders. The composite action theory has explained the results based on the tension and compression forces' growth at the adhesive layer between the CFRP plates and girder surface during the repair procedure. Other girders were prepared and repaired without turning over in order to avoid tension and compression forces at the adhesive layer. The experimental results show an increase in the dynamic parameters of CFRP repaired girders that were not turned over during the repair procedure, which aligns with the static-based results. The study concludes that the dynamic parameters are excellent indicators for the assessment of CFRP repaired concrete girders. The study also suggests that researchers should not turn over damaged concrete girders to repair them with CFRP plates if they intend to study the dynamic parameters, in order to avoid the proposed composite action effect on modal parameters.