• Title/Summary/Keyword: Resistant model

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Joint Shear Failure of Reinforced Concrete Interior Beam-Column Joint (내부 보-기둥 접합부의 전단파괴)

  • 이민섭;홍성걸
    • Proceedings of the Korea Concrete Institute Conference
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    • 2000.10a
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    • pp.303-308
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    • 2000
  • The design of column joint is an important part of earthquake resistant design of reinforced concrete moment resisting frames. Beam column joints must provide sufficient stiffness and strength to resist and sustain the loads induced by adjacent beams and columns. This paper investigates the difference of the current design codes which provide a different approach for the design of beam column joint in seismic zone. The model provided by Hitoshi Shiohara(1998) is reviewed in this paper, which provides a good relationship between moment and shear action of interior beam column joint and a role shear reinforcement according to their position.

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ROBUST FUZZY LINEAR REGRESSION BASED ON M-ESTIMATORS

  • SOHN BANG-YONG
    • Journal of applied mathematics & informatics
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    • v.18 no.1_2
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    • pp.591-601
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    • 2005
  • The results of fuzzy linear regression are very sensitive to irregular data. When this points exist in a set of data, a fuzzy linear regression model can be incorrectly interpreted. The purpose of this paper is to detect irregular data and to propose robust fuzzy linear regression based on M-estimators with triangular fuzzy regression coefficients for crisp input-output data. Numerical example shows that irregular data can be detected by using the residuals based on M-estimators, and the proposed robust fuzzy linear regression is very resistant to this points.

On the response of base-isolated buildings using bilinear models for LRBs subjected to pulse-like ground motions: sharp vs. smooth behaviour

  • Mavronicola, Eftychia;Komodromos, Petros
    • Earthquakes and Structures
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    • v.7 no.6
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    • pp.1223-1240
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    • 2014
  • Seismic isolation has been established as an effective earthquake-resistant design method and the lead rubber bearings (LRBs) are among the most commonly used seismic isolation systems. In the scientific literature, a sharp bilinear model is often used for capturing the hysteretic behaviour of the LRBs in the analysis of seismically isolated structures, although the actual behaviour of the LRBs can be more accurately represented utilizing smoothed plasticity, as captured by the Bouc-Wen model. Discrepancies between these two models are quantified in terms of the computed peak relative displacements at the isolation level, as well as the peak inter-storey deflections and the absolute top-floor accelerations, for the case of base-isolated buildings modelled as multi degree-of-freedom systems. Numerical simulations under pulse-like ground motions have been performed to assess the effect of non-linear parameters of the seismic isolation system and characteristics of both the superstructure and the earthquake excitation, on the accuracy of the computed peak structural responses. Through parametric analyses, this paper assesses potential inaccuracies of the computed peak seismic response when the sharp bilinear model is employed for modelling the LRBs instead of the more accurate and smoother Bouc-Wen model.

Experimental study on high gravity dam strengthened with reinforcement for seismic resistance on shaking table

  • Wang, Mingming;Chen, Jianyun;Fan, Shuli;Lv, Shaolan
    • Structural Engineering and Mechanics
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    • v.51 no.4
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    • pp.663-683
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    • 2014
  • In order to study the dynamic failure mechanism and aseismic measure for high concrete gravity dam under earthquake, the comparative models experiment on the shaking table was conducted to investigate the dynamic damage response of concrete gravity dam with and without the presence of reinforcement and evaluate the effectiveness of the strengthening measure. A new model concrete was proposed and applied for maintaining similitude with the prototype. A kind of extra fine wires as a substitute for rebar was embedded in four-points bending specimens of the model concrete to make of reinforced model concrete. The simulation of reinforcement concrete of the weak zones of high dam by the reinforced model concrete meets the similitude requirements. A tank filled with water is mounted at the upstream of the dam models to simulate the reservoir. The Peak Ground Acceleration (PGA) that induces the first tensile crack at the head of dam is applied as the basic index for estimating the overload capacity of high concrete dams. For the two model dams with and without strengthening tested, vulnerable parts of them are the necks near the crests. The results also indicate that the reinforcement is beneficial for improving the seismic-resistant capacity of the gravity dam.

Improvement of hysteretic constitutive model for reinforcements considering buckling

  • Weng Weipeng;Xie Xu;Wang Tianjia;Li Shuailing
    • Earthquakes and Structures
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    • v.25 no.1
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    • pp.57-67
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    • 2023
  • The buckling of longitudinal reinforcements under seismic loading accelerates the degradation of the bearing capacity of reinforced concrete columns. The traditional hysteretic constitutive model of reinforcement, which does not consider buckling, usually overestimates the seismic performance of pier columns. Subsequent researchers have also proposed many models including the buckling effects. However, the accuracy of these hysteretic constitutive models proposed for simulating the buckling behavior is inadequate. In this study, based on their works, the influence of historical events on buckling is considered, the path of the re-tensioning phase is corrected by adjusting the boundary lines, and the positions of the onset buckling point and compressive buckling path during each buckling deformation are corrected by introducing correction parameters and a boundary line. A modified hysteretic constitutive model is obtained, that can more accurately reflect the buckling behavior of reinforcements. Finally, a series of hysteresis tests of reinforcements with different slenderness ratios were then conducted. The experimental results verify the effectiveness of the proposed modified model. Indicating that the modified model can more accurately simulate the equivalent stress-strain relationship of the buckling reinforcement segment.

Development and Evaluation of a Web-based Education Program for Nursing Students on Control of Vancomycin-resistant Enterococcus Infection (간호학생을 위한 웹기반 VRE 감염관리 교육프로그램의 개발 및 효과)

  • Gong, Ju;Kang, Ji-Yeon
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.19 no.1
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    • pp.122-133
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    • 2012
  • Purpose: The purpose of this study was to develop a web-based education program on control vancomycin-resistant enterococci (VRE) infections and to identify the effects of the program on knowledge and performance of nursing students. Methods: The web-based VRE infection control education program was developed by using the network-based instructional systems design model. The nursing students in the experimental group could access this web-based education program at any time, and as many times as they wanted, during the clinical training period. Effects were evaluated by assessing knowledge and performance of VRE infection control measures during the clinical training period. Results: The contents of the education program included diagnosis, transmission, and treatment of VRE, contact precautions, hand washing, personal protective equipment, environment management, and quizzes. The lecture portion was filmed in a virtual screen studio using flash animation, video, and sound effects, and it was uploaded on an internet site. The knowledge and performance scores of the experimental group after using the education program were significantly higher than those of the control group. Conclusion: The results suggest that the web-based VRE infection control education program is an effective educational method to enhance knowledge and performance of VRE infection control measures.

Upregulation of Fas in epithelial ovarian cancer reverses the development of resistance to Cisplatin

  • Fan, Yang;Wang, Long;Han, Xuechuan;Liu, Xueqin;Ma, Hongyun;Ding, Yonghui
    • BMB Reports
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    • v.48 no.1
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    • pp.30-35
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    • 2015
  • This study was to investigate the role of Fas in the development of Cisplatin-resistant ovarian cancer. On the cellular level, Fas expression was significantly reduced in Cisplatin resistant A2780 (A2780/CP) cells compared with A2780 cells. Fas silence with siRNA would promote tumor cell lines proliferation, facilitate tumor cell cycle transition of G1/S, prevent cell apoptosis, and promote cell migration. Expression of drug resistance gene was negatively correlated to Fas. In nude mice metastasis model of human ovarian carcinoma by subcutaneous transplantation, after Ad-Fas injected intratumorly, we found that upregulation of Fas could inhibit transplantation tumor tissue growth and reduce the expression of drug resistance gene. Our results indicated that upregulation of Fas in epithelial ovarian cancer reversed the development of resistance to Cisplatin. In conclusion, our findings suggested that Fas might act as a promising therapeutic target for improvement of the sensibility to Cisplatin in ovarian cancer.

Resistance to Anthracnose Caused by Colletotrichum acutatum in Chili Pepper(Capsicum annuum L.)

  • Kim, Sang-Hoon;Yoon, Jae-Bok;Do, Jae-Wahng;Park, Hyo-Guen
    • Journal of Crop Science and Biotechnology
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    • v.10 no.4
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    • pp.277-280
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    • 2007
  • Pepper fruit anthracnose, caused by Colletotrichum acutatum, results in serious yield loss and affects crop quality in many Asian countries, making it a disease of economic consequence. A source resistant to C. acutatum was identified by the AVRDC within the line Capsicum chinense Jacq. PBC932. The resistant breeding line C. annuum AR is the $BC_3F_6$ generation derived from C. chinense Jacq. PBC932. The inheritance of resistance to C. acutatum was analyzed in segregating populations derived from the two crosses HN 11$\times$AR and Daepoong-cho$\times$AR. Detached mature green fruits were inoculated using microinjection method. The disease response was evaluated as the disease incidence at 7 DAI. The segregation ratios of resistance and susceptibility to C. acutatum in the $F_2$ and $BC_R$ populations derived from the two crosses fit significantly to a 1:3 Mendelian model. This indicates that the resistance of AR to C. acutatum is controlled by a single recessive gene.

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Inelastic seismic response of adjacent buildings linked by fluid dampers

  • Xu, Y.L.;Yang, Z.;Lu, X.L.
    • Structural Engineering and Mechanics
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    • v.15 no.5
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    • pp.513-534
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    • 2003
  • Using fluid dampers to connect adjacent buildings for enhancing their seismic resistant performance has been recently investigated but limited to linear elastic adjacent buildings only. This paper presents a study of inelastic seismic response of adjacent buildings linked by fluid dampers. A nonlinear finite element planar model using plastic beam element is first constructed to simulate two steel frames connected by fluid dampers. Computed linear elastic seismic responses of the two steel frames with and without fluid dampers under moderate seismic events are then compared with the experimental results obtained from shaking table tests. Finally, elastic-plastic seismic responses of the two steel frames with and without fluid dampers are extensively computed, and the fluid damper performance on controlling inelastic seismic response of the two steel frames is assessed. The effects of the fundamental frequency ratio and structural damping ratio of the two steel frames on the damper performance are also examined. The results show that not only in linear elastic stage but also in inelastic stage, the seismic resistant performance of the two steel frames of different fundamental frequencies can be significantly enhanced if they are properly linked by fluid dampers of appropriate parameters.

A Security Model for Duplication Resistant eSeal (복제 공격 저항성을 갖는 전자봉인 보안 모델)

  • Kim, Joo-Hae;Choi, Eun-Young;Lee, Dong-Hoon
    • Journal of the Korea Institute of Information Security & Cryptology
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    • v.17 no.5
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    • pp.111-116
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    • 2007
  • An eSeal(Electrical Seal) is an active RFID device which installed on the door of a container. The main role of the tag is to make sure the seal is not breaking by unauthorized people. Because an eSeal uses RFID system, we need to prevent eavesdrop and impersonate. Moreover, an eSeal which uses a secure protocol must not be able to duplicate. If duplication resistant property is not provide to a eSeal, an attacker may replace a object in the sealed container and reseal the container with duplicated eseal to hide breaking of the eSeal. In this paper, we provide a protocol which resist duplicate an eSeal during prevent eavesdrop and impersonation.