• Title/Summary/Keyword: simple tests

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Analysis and design for torsion in reinforced and prestressed concrete beams

  • Rahal, Khaldoun N.
    • Structural Engineering and Mechanics
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    • v.11 no.6
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    • pp.575-590
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    • 2001
  • This paper presents a simplified method for the design and analysis of non-prestressed, partially prestressed, and fully prestressed concrete beams subjected to pure torsion. The proposed model relates the torsional strength to the concrete compressive strength and to the amounts of transverse and longitudinal reinforcement. To check the adequacy of this simple method, the calculated strength and mode of failure are checked against the experimental results of 17 prestressed concrete 66 reinforced concrete beam tests available in the literature, and very good agreement is found. The simplicity of the method is illustrated by two examples, one for design and another for analysis.

XML-Based Network Management for IP Networks

  • Choi, Mi-Jung;Hong, James W.;Ju, Hong-Taek
    • ETRI Journal
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    • v.25 no.6
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    • pp.445-463
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    • 2003
  • XML-based network management, which applies XML technologies to network management, has been proposed as an alternative to existing network management. The use of XML in network management offers many advantages. However, most existing network devices are already embedded with simple network management protocol (SNMP) agents and managed by SNMP managers. For integrated network management, we present the architectures of an XML-based manager, an XML-based agent, and an XML/SNMP gateway for legacy SNMP agents. We describe our experience of developing an XML-based network management system (XNMS), XML-based agent, and an XML/SNMP gateway. We also verify the effectiveness of our XML-based agent and XML/SNMP gateway through performance tests. Our experience with developing XNMS and XML-based agents can be used as a guideline for development of XML-based management systems that fully take advantage of the strengths of XML technologies.

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Fatigue Reliability and Remaining Fatigue Life of Existing Steel Rail-Road Bridges (강철도교의 피로신뢰성과 잔존피로수명)

  • 조효남;신재철;허상구
    • Proceedings of the Computational Structural Engineering Institute Conference
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    • 1989.04a
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    • pp.11-16
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    • 1989
  • This paper presents a fatigue reliability model for the reliability-based evaluation of remaining fatigue life of existing rail-road bridges. It is demonstrated that the simple fatigue reliability model based on the Weibull distribution of fatigue life can be extended by incorporating various effects due to the rate of the train-traffic increase and in-service Inspections. The paper also suggests the system fatigue reliability analysis using an approximate formulation and 2nd-order bound solutions. The application of the proposed model to existing rail-road brdiges based on field load tests shows that it may be practically used for the assessment of fatigue reliability, remaining life, and in-service inspection scheduling of existing rail-road bridges.

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Wave Transformation near the Surfzone on the Arbitrary Beach Profile (불규칙한 수심단면에서 쇄파대 부근의 파고변형)

  • Choi, Han-Kyu;Gang, Jang-Su;Lee, Cheol-Eung
    • Journal of Industrial Technology
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    • v.17
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    • pp.261-275
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    • 1997
  • The objective of this paper is to develop two numerical model for predicting the wave height with set-up/down near the surfzone on a arbitrary beach profile. Two wave models, regular wave model and random wave model, are based on the energy flux equation with the energy dissipation effects. The developed numerical models are verified by comparison of numerical results with analytical solutions that are derived under the simple conditions. The characteristics of parameters included in each model are then investigated and decided to the range of behaviour by the sensitivity analysis. For sensitivity analysis, we carried out total 46 laboratory tests. Finally, the developed numerical models are applied to the field where the wave height near the surfzone has been measured. From the applications of numerical models, it is concluded that the developed numerical models may accurately predict the wave height with the set-up/down near the surfzone on a arbitrary beach profile.

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Experience of the Application of a Rock Cracking Method Using Steam Pressure to Tunnel Excavation (증기압을 이용한 파암공법의 현장 적용성 연구)

  • Kim, Duk-young;Kim, Sun-Woong
    • Explosives and Blasting
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    • v.35 no.2
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    • pp.1-8
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    • 2017
  • In this study, the characteristics of a new rock cracking method using steam pressure are briefly presented. The rock cracking method was originally developed as a means to decrease the ground vibrations from underground rock excavations. The validation tests were also conducted by applying the method to an actual rock tunnel under construction. The ground vibrations were measured in the vicinity of the test site. The measured vibration results were compared with the values predicted by an attenuation equation, which had been proposed by a company in Japan. Also, a simple cost assessment for the method was conducted to demonstrate its cost effectiveness in underground tunnel excavations.

Fabrication of Nano-Size Specimens for Tensile Test Employing Nano-Indentation Device (나노 인장시험을 위한 압축 시험기용 인장시편 제작에 관한 연구)

  • Lim, Tae Woo;Yang, Dong-Yol
    • Journal of the Korean Society for Precision Engineering
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    • v.32 no.10
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    • pp.911-916
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    • 2015
  • In the nano/micro scale, material properties are dependent on the size-scale of a structure. However, conventional micro-scale tensile tests have limitations to obtain reliable values of nano-scale material properties owing to residual stress and elastic slippage in the gripping/aligning process. The indenter-driven nano-scale tensile test provides prominent advantages simple testing device, high-quality nano-scale metallic specimen with negligible residual stress. In this paper, two-types of specimens (a specimen with multi-testing parts and a specimen with a single-testing part) are discussed. Focused ion beam (FIB) is employed to fabricate a nano-scale specimen from a thin nickel film. Using the specimen with a single-testing part, we obtained a nano-scale stress-strain curve of electroplated nickel film.

Comparisons of internal self-field magnetic flux densities between recent Nb3Sn fusion magnet CICC cable designs

  • Kwon, S.P.
    • Progress in Superconductivity and Cryogenics
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    • v.18 no.3
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    • pp.10-20
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    • 2016
  • The Cable-In-Conduit-Conductor (CICC) for the ITER tokamak Central Solenoid (CS) has undergone design change since the first prototype conductor sample was tested in 2010. After tests showed that the performance of initial conductor samples degraded rapidly without stabilization, an alternate design with shorter sub-cable twist pitches was tested and discovered to satisfy performance requirements, namely that the minimum current sharing temperature ($T_{cs}$) remained above a given limit under DC bias. With consistent successful performance of ITER CS conductor CICC samples using the alternate design, an attempt is made here to revisit the internal electromagnetic properties of the CICC cable design to identify any correlation with conductor performance. Results of this study suggest that there may be a simple link between the $Nb_3Sn$ CICC internal self-field and its $T_{cs}$ performance. The study also suggests that an optimization process should exist that can further improve the performance of $Nb_3Sn$ based CICC.

Experimental investigation into brick masonry arches' (vault and rib cover) behavior reinforced by FRP strips under vertical load

  • Takbash, Majid Reza;Morshedi, Abbas Ali Akbarzadeh;Sabet, Seyyed Ali
    • Structural Engineering and Mechanics
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    • v.67 no.5
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    • pp.481-492
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    • 2018
  • The current experimental study is the reinforcement of the simple curvature vault masonry structures. In this study, we discuss complex structure include vault and rib cover with two radii and actual dimensions under a vertical load. The unreinforced structure data were compared with analysis data. The analysis data are in good agreement with experimental data. In the first experiment, a structure without reinforcement is tested and according to the test results, the second structure was reinforced using the carbon polymer fibers and the same test is done to see the effects of reinforcement. Based on the test results of the first structure, the first cracks are created in the vault. Moreover, the reinforcement with carbon fibers will increase the loading capacity of the structure around 35%.

Dual priming oligonucleotide system for the multiplex detection of tuberculosis in Hanwoo

  • Shin, Jong-Bong;Park, Nam-Yong;Kim, Yong-Hwan;Cho, Ho-Seong
    • Korean Journal of Veterinary Service
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    • v.30 no.4
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    • pp.527-532
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    • 2007
  • In present study, we described the reliability of the dual priming oligonucleotide (DPO) multiplex polymerase chain reaction (PCR) for the detection of Mycobacterium tuberculosis complex (MTC) and non-Mycobacterium tuberculosis (NMT) in blood samples of the Korea native cattle, Hanwoo. Among 340 samples 22 (6.5%) were positive in using DPO multiplex PCR, 21 (6.2%) were positive in PCR. The relative agreement between 2 tests was 99.7%, and the agreement quotient (kappa), was 0.95 (excellent). In these results, we demonstrated the successful application of DPO multiplex PCR for the diagnosis of bovine tuberculosis in Hanwoo. Multiplex PCR, using DPO primers, can be useful for the simple diagnosis of bovine tuberculosis in bovine blood samples.

A Study of Correlation between Experiment and Analysis of Nonlinear Behaviors of A 1:5 Scale RC Frame with Nonseismic Details (비내진 상세를 가진 1:5 축소 철근콘크리트 골조의 비선형 거동에 대한 실험과 해석의 상관성 연구)

  • 이한선;우성우;허윤섭
    • Proceedings of the Korea Concrete Institute Conference
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    • 1999.10a
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    • pp.483-486
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    • 1999
  • A series of dynamic and static tests were conducted to observe the actual responses of a 1:5 scale 3-story reinforced concrete (RC) frame which was designed only for gravity loads. One of the major objectives of these experiments are to provide the calibration to the available static and dynamic inelastic techniques. In this study, the experimental results were simulated by using a nonlinear analysis program for reinforced concrete frame, IDARC-2D. The evaluation of the degree of the simulation leads to the conclusion that while the global behaviors such as story drifts and shears can be in general simulated with the limited accuracy in the dynamic nonlinear analysis, it is rather easy and simple to get the fairly high level of accuracy in the prediction of global and local behaviors in the static nonlinear analysis by using IDARC-2D.

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