• Title/Summary/Keyword: A321

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Experimental-numerical study on the FRP-strengthened reinforced concrete beams with a web opening

  • Abdullah Rafiq Safiaa;Suryamani Behera;Rimen Jamatia;Rajesh Kumar;Subhajit Mondal
    • Advances in concrete construction
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    • v.15 no.5
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    • pp.321-331
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    • 2023
  • The effect of fibre-reinforced polymer (FRP) strengthening on the behaviour of reinforced concrete (RC) beams with web openings is studied. It has been observed that the load-carrying capacity and deflection in the presence of an opening reduced by approximately 50% and 75%, respectively. Three-dimensional nonlinear finite models are first validated with the results obtained from experimental data. Thereafter, a series of parametric studies are conducted for the beam with an opening. In the study, it is observed that a square opening shape is critical in comparison to the elliptical and circular-shaped opening. The web opening located near the support is found to be critically compared to the opening in the middle of the beam. Given the critical opening shape situated at the critical location, the increase in FRP layers enhances the load-deformation behaviour of the FRP-wrapped RC beam. However, the load-deformation responses are not significantly improved beyond a certain threshold value of FRP layers.

Fatigue crack propagation life evaluation of an autofrettaged thick-walled cylinder (자긴가공된 두꺼운 실린더의 피로균열 전파수명평가)

  • Lee, Song-In;Kim, Jin-Yong;Jeong, Se-Hui;Go, Seung-Gi
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.22 no.2
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    • pp.321-329
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    • 1998
  • To ensure the structural integrity of the autofrettaged thick-walled cylinder subjected to cyclic internal pressure loading, the fatigue crack propagation life of the cylinder was evaluated. Stress intensity factors of the external cracked cylinder due to internal pressure and autofrettage loadings were calculated using the finite element method. The fatigue crack propagation lives of the cylinder based on the fracture mechanics concepts were predicted and compared to the experimental fatigue lives evaluated from the C-shaped simulation specimens. There were good correlations between the predicted and experimental fatigue lives within a factor of 3 for the single and double grooved C-shaped simulation specimens. Predicted fatigue crack propagation lives of the double grooved cylinders were about 1.5-5 times longer than those of the single grooved cylinders depending on the levels of autofrettage.

Structural and Optical Properties of Multilayer Films of IGZO / Ag / IGZO for Low Emissivity Applications (Low-e용 산화물 다층박막 IGZO/Ag/IGZO의 구조적, 광학적 특성 분석)

  • Wang, Hong Rae;Kim, Hong Bae;Lee, Sang Yeol
    • Journal of the Korean Institute of Electrical and Electronic Material Engineers
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    • v.26 no.4
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    • pp.321-324
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    • 2013
  • In this study, The RF magnetron sputter and evaporator was on glass substrates 30 mm ${\times}$ 30 mm OMO multilayer thin film structure is applied to the low-e. Structural and optical properties, a thin film was produced, the variable was placed into a variable deposition time of the oxide layer. According to the XRD measurement results there is no peak that satisfies the Bragg's law ($2dsin{\theta}=n{\lambda}$) which confirmed that it is an amorphous structure. RMS value of the results of the AFM measurement, has a roughness of less than 2 nm. transmittance measurements results, visible light region an average 80%, IR region 40% showed.

EXPLICIT SOBOLEV ESTIMATES FOR THE CAUCHY-RIEMANN EQUATION ON PARAMETERS

  • Cho, Sang-Hyun;Choi, Jae-Seo
    • Bulletin of the Korean Mathematical Society
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    • v.45 no.2
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    • pp.321-338
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    • 2008
  • Let $\bar{M}$ be a smoothly bounded pseudoconvex complex manifold with a family of almost complex structures $\{L^{\tau}\}_{{\tau}{\in}I}$, $0{\in}I$, which extend smoothly up to bM, the boundary of M, and assume that there is ${\lambda}{\in}C^{\infty}$(bM) which is strictly subharmonic with respect to the structure $L^0|_{bM}$ in any direction where the Levi-form vanishes on bM. We obtain explicit estimates for the $\bar{\partial}$-Neumann problem in Sobolev spaces both in space and parameter variables. Also we get a similar result when $\bar{M}$ is strongly pseudoconvex.

Efficient Test Data Compression and Low Power Scan Testing in SoCs

  • Jung, Jun-Mo;Chong, Jong-Wha
    • ETRI Journal
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    • v.25 no.5
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    • pp.321-327
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    • 2003
  • Testing time and power consumption during the testing of SoCs are becoming increasingly important with an increasing volume of test data in intellectual property cores in SoCs. This paper presents a new algorithm to reduce the scan-in power and test data volume using a modified scan latch reordering algorithm. We apply a scan latch reordering technique to minimize the column hamming distance in scan vectors. During scan latch reordering, the don't-care inputs in the scan vectors are assigned for low power and high compression. Experimental results for ISCAS 89 benchmark circuits show that reduced test data and low power scan testing can be achieved in all cases.

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Design of high power traveling wave rotary type ultrasonic motor (고 출력 진행파 회전형 초음파 모터의 설계)

  • Oh, Jin-Heon;Lim, Kee-Joe
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2010.06a
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    • pp.321-321
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    • 2010
  • In this paper, we propose a novel type shaft-less ring type ultrasonic motor. A traveling wave rotary type ultrasonic motor is selected as a base model. The newly designed stator has two piezoelectric ceramic rings which are bonded in sandwich shape as traveling wave generator. So, we can expect to produce higher torque. The proposed model has the rotor structure that coupled with the stator provokes the pressure, this model do not install the separate plate any spring device. We used the finite element method to verify the operation principle and to compute the vibration mode of proposed model.

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A Design and Implementation of SMTPUTF8 Mail Server to Support EAI(E-Mail Address Internationalization) bis Standard (EAI(E-Mail Address Internationalization) bis 표준을 지원하는 SMTPUTF8 메일 서버의 설계 및 구현)

  • Han, Dongyun;Kim, Kyongsok
    • Journal of Information Technology Services
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    • v.12 no.2
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    • pp.321-334
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    • 2013
  • Recently EAI WG of IETF has published standards for multilingual support in the local part of the e-mail address. Between 2009 and 2010, EAI WG published RFC documents, called the EAI standard, extension to the existing mail-related RFC documents, and EAI has been implemented and tested. In the course of reviewing the results, this yielded a proposal to modify the EAI standard. As a result, EAI WG has published modified RFC documents, called the EAI bis standard. SMTPUTF8 mail server described in this paper has been implemented according to the EAI bis standard. In addition, it has the ability to support two different standards to support the multilingual domain part of the e-mail address, IDNA and EAI bis. Futhermore, SMTPUTF8 mail server can encode in punycode the local part of the e-mail address. Finally, interoperability testing shows that SMTPUTF8 mail server is well-implemented according to the EAI bis standard.

A new approach to determine the moment-curvature relationship of circular reinforced concrete columns

  • Caglar, Naci;Demir, Aydin;Ozturk, Hakan;Akkaya, Abdulhalim
    • Computers and Concrete
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    • v.15 no.3
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    • pp.321-335
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    • 2015
  • To be able to understand the behavior of reinforced concrete (RC) members, cross sectional behavior should be known well. Cross sectional behavior can be best evaluated by moment-curvature relationship. On a reinforced concrete cross section moment-curvature relationship can be best determined by both experimentally or numerically with some complicated iteration methods. Making these experiments or iterations manually is very difficult and not practical. The aim of this study is to research the efficiency of Neural Networks (NN) as a more secure and robust method to obtain the moment-curvature relationship of circular RC columns. It is demonstrated that the NN based model is highly successful to determine the moment-curvature relationship of circular reinforced concrete columns.

A study on isolated microorganisms from dental cast (석고 모형으로부터 분리 배양된 미생물에 관한 연구)

  • Choi, Ju-Young
    • Journal of Technologic Dentistry
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    • v.35 no.4
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    • pp.321-332
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    • 2013
  • Purpose: This study was examined the characteristics of bacteria isolated from the dental stone that is made ??in the dental laboratory. Methods: 104 dental stones samples were collected from the 4 dental laboratory. Characteristics of bacteria were investigated by microorganism isolation culture method using a Blood Tryptic Soy Agar(TSA) medium. Results: The detected various bacteria was confirmed as pathogenic bacteria, non-pathogenic bacteria and natural bacteria. The isolated bacterial number was confirmed $2.9{\times}10^3CFU$ and maxium bacterial number of $3.0{\times}10^4CFU$. Conclusion: Therefore, infection prevention education is required, it must be to live up the hand-washing and wear protective clothing to protect themselves when working in a dental laboratory.

Microstructure and Nano-hardness of SiC/C Multi-coated Layers on a Particulate Nuclear Fuel (입자 핵연료의 SiC/C 다층 도포층의 미세조직 및 극미세 경도 평가)

  • Choi, Young
    • Journal of the Korean institute of surface engineering
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    • v.52 no.6
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    • pp.321-325
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    • 2019
  • Triso-type coating layers of silicon carbide and graphite on UO2 paticulate nuclear fuel were prepared by using fluidized bed type chemical vapor deposition and self-propagating high temperature synthesis methods to make a coated nuclear fuel of a power plant for hydrogen mass-production. The source and carrier gases were the mixture of methyltrichlorosilane and propane, and inert argon. Chemical analysis and microstructure observation showed that the coated layers were inner graphite, middle silicon carbide and outer graphite. The elastic modulus and nano-hardness of the silicon carbide layer were 503 [GPa] and 36 [GPa], respectively.