• Title/Summary/Keyword: reinforcement orientation

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The Impacts of Communication Reinforcement on Performance of Learning in Web-PBL (Web-PBL환경에서 커뮤니케이션 강화가 학습성과에 미치는 영향)

  • Ko, Yun-Jung;Kang, Ju-Seon;Ko, Il-Sang
    • Asia pacific journal of information systems
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    • v.16 no.4
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    • pp.179-202
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    • 2006
  • The objective of this study is to identify the impacts of communication reinforcement on performance of learning in Web-PBL. Communication reinforcement is defined as the combination of information sharing and co-construction. As factors facilitating communication reinforcement, we propose learner's characteristics, task characteristics, and group characteristics. Learner's characteristics are collaboration-orientation, openness, holistic approach, and online community-orientation which reflects e-learning environment. Collaboration-oriented tasks as group projects were developed and given to groups with 5-6 members. The group characteristics are categorized into 'horizontal' and 'vertical', according to the patterns of communication between a group leader and members. To verify empirically the proposed research model, an experimental design was performed to learners who took on-line and off-line courses with group projects. We found important results as follows; First, field dependence has positive impacts on information sharing, and online community-orientation has positive impacts on co-construction. These results correspond with prior studies on relationship between field dependence and collaborative learning. Second, collaboration-oriented task directly impacts on information sharing, and indirectly affects co-construction, This result implicates that information sharing is pre-requisite of co-construction. Third, 'horizontal' was identified as a factor giving positive effects on information sharing and co-construction. This result implies that horizontal communication is very important to facilitate communication reinforcement.

The Mechanical Property by Fiber Orientation Distributions in Fiber-Reinforced Polymeric Composites (섬유강화 고분자 복합재료에서 섬유배향상태에 따른 기계적 성질)

  • Lee, Dong-Gi;Sim, Jae-Ki;Han, Gil-Young;Kim, Hyuk;Kim, Jin-Woo;Lee, Jung-Ju
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2003.04a
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    • pp.202-205
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    • 2003
  • Investigated whether fiber orientation situation of fiber reinforcement macromolecule composition board and the fiber inclusion rate are perpendicular and horizontal direction tensile strength and some correlation. Fiber orientation situation of tensile strength of 0 direction of composition board increased changelessly by aeolotropy in isotropy. Tensile strength of 90 direction that is isotropy and tensile strength of 0 direction that is aeolotropy agreed almost. Get into aeolotropy, the reinforcement rate of fiber decreased. When load interacts for width direction of reinforcement.

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The comparison of the tensile strength of fiber-reinforced composites according to the change of fiber orientat and fiber orientation angle in one direction (섬유배향과 일방향 섬유배향각 변화에 다른 복합재료의 인장강도 비교)

  • Kim Jin-Woo;Lee Jung-Ju;Lee Dong-Gi
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2004.04a
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    • pp.284-287
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    • 2004
  • After we experiment one direction fiber reinforced composites$(\theta\;=\;0^{\circ},\;J=1)$ to the X direction$(\theta\;=\;0^{\circ},\;J=1)$, we can say that fiber orientation efficiency and fiber orientation angle efficiency become lower. It is because the more the fabric is orientated in a equal direction with one direction fiber floor the more the load given from the exterior becomes shear rather than tension, even though one direction fiber floor gets the most of the exterior power. when fiber content ration is $10wt\%$, the fiber reinforcement efficiency of J=0.3 is similar with the fiber reinforcement efficiency of $\theta=30^{\circ}$ We also found that the fiber reinforcement efficiency of J=0.2 is similar with the fiber reinforcement efficiency of $\theta=20^{\circ}$ in case of $20wt\%$.

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Finite element modelling of reinforced concrete structures with laboratory verification

  • Cheng, Y.M.
    • Structural Engineering and Mechanics
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    • v.3 no.6
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    • pp.593-609
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    • 1995
  • The presence of reinforcement has a significant influence on the stress-strain behaviour of reinforced concrete structures, expecially when the failure stage of the structures is approached. In the present paper, the constrained and non-constrained zones of concrete due to the presence of reinforcement is developed and the stress-stress-strain behaviour of concrete is enhanced by a reinforcement confinement coefficient, Furthermore, a flexible method for the modelling of reinforcement with arbitrary orientation and not passing the nodes of concrete element is also proposed. Numerical examples and laboratory tests have shown that the coefficient and the modelling technique proposed by the author are satisfactory.

Study on Levee Visual Inspection Information System Building Using Mobile Technology

  • Kang, Seung-Hyun;Lee, Jong-Min
    • Journal of the Korea Society of Computer and Information
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    • v.21 no.6
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    • pp.71-76
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    • 2016
  • In this paper, we propose the mobile visual inspection information system using DGPS and portable range finder for levee safety inspection. Instead of existing visual inspection management method that is stored hand-written data, this system is designed to manage directly the visual inspection information using mobile devices in the field of levee. And through extracting accurate DGPS coordinates information about damage location of levee, this system is developed to ensure efficiency for the main task arising from the levee site such as inspection, maintenance and reinforcement. Furthermore, when damage has occurred at the point that inspector is not able to approach, this system can record the damage site data correctly, by converting data such as position, orientation and height of the damage point into the World Geodetic System coordinates. The position, orientation and height data was extracted automatically through the DGPS and portable range finder. And by applying the augmented reality method, this system was implemented for inspector to revisit the point of damage easily in order to perform the management, maintenance and reinforcement of the levee later.

On vibrations of functionally graded carbon nanotube (FGCNT) nanoplates under moving load

  • Alaa A. Abdelrahman;Ismail Esen;Mohammed Y. Tharwan;Amr Assie;Mohamed A Eltaher
    • Advances in nano research
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    • v.16 no.4
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    • pp.395-412
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    • 2024
  • This article develops a nonclassical size dependent nanoplate model to study the dynamic response of functionally graded carbon nanotube (FGCNT) nanoplates under a moving load. Both nonlocal and microstructure effects are incorporated through the nonlocal strain gradient elasticity theory. To investigate the effect of reinforcement orientation of CNT, four different configurations are studied and analysed. The FGM gradation thorough the thickness direction is simulated using the power law. In the context of the first order shear deformation theory, the dynamic equations of motion and the associated boundary conditions are derived by Hamilton's principle. An analytical solution of the dynamic equations of motion is derived based on the Navier methodology. The proposed model is verified and compared with the available results in the literature and good agreement is found. The numerical results show that the dynamic performance of FGCNT nanoplates could be governed by the reinforcement pattern and volume fraction in addition to the non-classical parameters and the moving load dimensionless parameter. Obtained results are reassuring in design and analysis of nanoplates reinforced with CNTs.

Experimental study on effect of EBRIG shear strengthening method on the behavior of RC beams

  • Shomali, Amir;Mostofinejad, Davood;Esfahani, Mohammad Reza
    • Advances in concrete construction
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    • v.8 no.2
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    • pp.145-154
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    • 2019
  • The present experimental study addresses the structural response of reinforced concrete (RC) beams strengthened in shear. Thirteen RC beams were divided into four different sets to investigate the effect of transverse and longitudinal steel reinforcement ratios, concrete compressive strength change and orientation for installing carbon fiber-reinforced polymer (CFRP) laminates. Then, we employed a shear strengthening solution through externally bonded reinforcement in grooves (EBRIG) and externally bonded reinforcement (EBR) techniques. In this regard, rectangular beams of $200{\times}300{\times}2000mm$ dimensions were subjected to the 4-point static loading condition and their load-displacement curves, load-carrying capacity and ductility changes were compared. The results revealed that using EBRIG method, the gain percentage augmented with the increase in the longitudinal reinforcement ratio. Also, in the RC beams with stirrups, the gain in shear strength decreased as transverse reinforcement ratio increased. The results also revealed that the shear resistance obtained by the experimental tests were in acceptable agreement with the design equations. Besides, the results of this research indicated that using the EBRIG system through vertical grooves in RC beams with and without stirrups caused the energy absorption to increase about 85% and 97%, respectively, relative to the control.

Goal Regulation Mechanism through Reinforcement Learning in a Fractal Manufacturing System (FrMS) (프랙탈 생산시스템에서의 강화학습을 통한 골 보정 방법)

  • Sin Mun-Su;Jeong Mu-Yeong
    • Proceedings of the Korean Operations and Management Science Society Conference
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    • 2006.05a
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    • pp.1235-1239
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    • 2006
  • Fractal manufacturing system (FrMS) distinguishes itself from other manufacturing systems by the fact that there is a fractal repeated at every scale. A fractal is a volatile organization which consists of goal-oriented agents referred to as AIR-units (autonomous and intelligent resource units). AIR-units unrestrictedly reconfigure fractals in accordance with their own goals. Their goals can be dynamically changed along with the environmental status. Since goals of AIR-units are represented as fuzzy models, an AIR-unit itself is a fuzzy logic controller. This paper presents a goal regulation mechanism in the FrMS. In particular, a reinforcement learning method is adopted as a regulating mechanism of the fuzzy goal model, which uses only weak reinforcement signal. Goal regulation is achieved by building a feedforward neural network to estimate compatibility level of current goals, which can then adaptively improve compatibility by using the gradient descent method. Goal-oriented features of AIR-units are also presented.

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Effect of Fiber Orientation on the Tensile Strength in Twisted Yarn Composites (Twisted Yarn 복합재료에서 인장강도에 미치는 섬유배향의 영향)

  • Lee, Dong-Ki;Sim, Jae-Ki;Kim, Hyuk;Kim, Jin-Woo;Lee, Jung-Ju;Lee, Ha-Wook
    • Proceedings of the Korean Society of Precision Engineering Conference
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    • 2003.06a
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    • pp.422-425
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    • 2003
  • Investigated whether fiber orientation distribution of twisted yarn composites and the fiber content are 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength and some correlation. Tensile strength of 0$^{\circ}$ directions of twisted yarn composites increased changelessly being proportional the fiber content and fiber orientation function get into anisotropic in isotropic. But, tensile strength ratio by separation of fiber filament of 90$^{\circ}$ directions tensile strength decreased when tensile load is imposed for width direction of reinforcement fiber. 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio value of a twisted yarn composites not receive almost effect of the fiber content of fiber orientation function J = 0.4 lows. Although do, 20 wt% of the fiber content is high about 0$^{\circ}$ and 90$^{\circ}$ direction tensile strength ratio about 1.6~2 than 10 wt% from J = 0.4. Therefore. could know that effect of the fiber content is dominate.

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Stability Analysis of the Reinforced Embankment on Soft Foundations using the Limit Equilibrium Method (한계평형법에 의한 연약지반 보강성토의 안정해석)

  • 고남영;고홍석
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.37 no.5
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    • pp.101-110
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    • 1995
  • The use of geotextile as reinforced materials in Soil structures has become widespread throughout the world. Geotextile reinforcement has been used in retaining walls, slope of embankment and especially soft foundation, etc. In the past, however, its design and construction have been performed empirically. In this study, to investigate of the effect of geotextiles reinforced slope of the embankment on a very soft foundation, a limit equilibrium analysis program calculating the safety factor of embankment on very soft foundation was developed. The study was focussed on such factors as type of geotextile, tensile strength, amount of reinforcement, and inclination of embankment. And the 4imit equilibrium analysis program was written on the basis of Low's slope stability theory with some modification. The following conclusions were drawn from this study. (1) The orientation of reinforcement can be assumed either horizontal or tangential to the slip circle. The factor of safety with tangential reinforcement is larger than that with the horizontal reinforcement. (2) In general, the factor of safety increases, as the slope reduces. However, it is preferable to use geotextiles with higher tensile strength rather than to reduce the slope of the embankment, because it is difficult to adjust the slope as desired. (3) The factor of safety obtained by numerical computation is affected only by the tensile strength, but not by the type of the geotextile.

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