• Title/Summary/Keyword: Impact coefficients

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A study on the Impact force of floating body which acts on near shore structures - On the horizontal force acts on the vertical circular piles - (해안 구조물에 작용하는 부유체의 충격력에 관한 연구(I) - 연직원주에 작용하는 수평력 -)

  • Yang, Yun-Mo;Kim, Byeong-Uk;Kim, Do-Sam
    • Proceedings of the Korea Water Resources Association Conference
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    • 1982.07a
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    • pp.105-120
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    • 1982
  • The circular cylindrical piles are extensively used in near shore structures. For the purpose of analysing stability of vertical pile, we must consider the horizontal force, the lift force, and the traverse force etc. In this paper author studied horizontal force acts on the vertical circular pile and investigated the relation between the floating body coefficients C$$ and U$$T/D.

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Genotypic and Environmental Effects on Cookie Quality of Korean Winter Wheat

  • Hong, Byung-Hee;Park, Chul-Soo;Baik, Byung-Kee
    • KOREAN JOURNAL OF CROP SCIENCE
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    • v.46 no.5
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    • pp.352-359
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    • 2001
  • Cookie baking properties and relationships between cookie baking properties and flour characteristics were evaluated for two years, 1997 and 1998, and at two locations, Suwon and Deokso, with Korean winter wheat cultivars and lines. Cookie baking parameters, except for cookie diameter and top grain score, were influenced by locations and years. Chokwang, Suwon 274, Suwon 275, Suwon 277 and Urimil showed larger cookie diameter and excellent top grain score compared to the other Korean winter wheat cultivars and lines. Among the flour characteristics, protein content, damaged starch content, alkaline water retention capacity and flour swelling volume showed high positive correlation coefficients with cookie baking parameters. Friabilin-present lines showed larger cookie diameter, suitable surface structure of cookie and softer snapping force than the friabilin-absent lines.

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Use of similarity indexes to identify spatial correlations of sodium void reactivity coefficients

  • Jimenez-Carrascosa, Antonio;Garcia-Herranz, Nuria
    • Nuclear Engineering and Technology
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    • v.52 no.11
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    • pp.2442-2451
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    • 2020
  • The safety level of Sodium Fast Reactors is directly related with the sodium void reactivity. A low-void effect design has been proposed within the Horizon2020 ESFR-SMART project thanks to the introduction of a sodium plenum above the active core. In order to assess the impact of this core conception on transient analysis, a map with the spatial distribution of sodium void worth can be computed and fed into a point-kinetics-based transient code. Due to the spatial correlations between neighboring zones, the global effect of voiding two different axial or radial regions is not necessarily the sum of both individual contributions. Neglecting those correlations in the void worth map and consequently in the transient analysis may lead to an unrealistic prediction of the transient sequences. In this work, a method based on sensitivity analysis and similarity assessment is proposed for predicting those correlations. The method proved to be able to establish correlations between axial slices of a sub-assembly and was checked against realistic sodium void propagation patterns.

Behaviour Analyses of Ocean Structure Due to Ship Collision (선박의 충돌로 인한 해양구조물의 거동 해석)

  • 이호영
    • Proceedings of the Korea Committee for Ocean Resources and Engineering Conference
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    • 2001.05a
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    • pp.103-107
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    • 2001
  • When ship claps against the ocean structure sited at shallow water, the time simulation of motion responses of dolphin-moored ocean structure is presented. The equatien of motion based on Cummin's theory of impulse responses are employed, and solved in time domain by using the Newmark $\beta$ method. The added mass and damping coefficients involved in the equations are obtained from a three-dimensional panel method in the frequency domain. The impact forces due to ship collision are modeled as two method, and those are elastic and non-elastic collisions. The mooring forces for dolphin systems of scean structure are considered as linear spring system.

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Impact of Self-Directed Learning Ability and Metacognition on Clinical Competence among Nursing Students (간호학생의 자기주도 학습능력과 메타인지가 임상수행능력에 미치는 영향)

  • Jho, Mi Young;Chae, Myung-Ock
    • The Journal of Korean Academic Society of Nursing Education
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    • v.20 no.4
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    • pp.513-522
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    • 2014
  • Purpose: This study identifies the influences of self-directed learning ability and metacognition on clinical competence in nursing students. Method: The subjects consisted of 290 second and third year nursing students. The data were analyzed using t-tests, ANOVA, Scheffe's test, Pearson's correlation coefficients and multiple linear regression via SPSS Statistics version 18.0. Results: On a scale of 1 (lowest) to 5 (highest), the mean self-directed learning ability score of the subjects was 3.19, mean metacognition score was 3.36 and mean clinical competence score was 3.29. A positive correlation was found between clinical competence with self-directed learning ability and metacognition. The strongest predictor of clinical competence was metacognition. Conclusion: To improve the clinical competence of nursing students, these findings indicate that increasing metacognition ability is required.

A new bridge-vehicle system part I: Formulation and validation

  • Chan, Tommy H.T.;Yu, Ling;Yung, T.H.;Chan, Jeffrey H.F.
    • Structural Engineering and Mechanics
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    • v.15 no.1
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    • pp.1-19
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    • 2003
  • This paper presents the formulation of a new bridge-vehicle system with validation using the field data. Both pitching and twisting modes of the vehicle are considered in the contribution of the dynamic effects in the bridge responses. A heavy vehicle was hired as a control vehicle with known axle weight, axle spacing and spring coefficients. The measured responses were generated from the control vehicle running at a particular speed at a test span at Ma Tau Wai Flyover. The measured responses were acquired using strain gauges installed beneath the girder beams of the test bridge. The simulated responses were generated using BRVEAN that is a self-developed program based on the proposed bridge-vehicle system. The validation shows that the bridge model is valid for representing the test bridge and the governing equations are valid for representing the motion of moving vehicles.

Homogenized thermal properties of 3D composites with full uncertainty in the microstructure

  • Ma, Juan;Wriggers, Peter;Li, Liangjie
    • Structural Engineering and Mechanics
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    • v.57 no.2
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    • pp.369-387
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    • 2016
  • In this work, random homogenization analysis for the effective thermal properties of a three-dimensional composite material with unidirectional fibers is presented by combining the equivalent inclusion method with Random Factor Method (RFM). The randomness of the micro-structural morphology and constituent material properties as well as the correlation among these random parameters are completely accounted for, and stochastic effective thermal properties as thermal expansion coefficients as well as their correlation are then sought. Results from the RFM and the Monte-Carlo Method (MCM) are compared. The impact of randomness and correlation of the micro-structural parameters on the random homogenized results is revealed by two methods simultaneously, and some important conclusions are obtained.

Dynamic stress intensity factors for two parallel cracks in an infinite orthotropic plate subject to an impact load

  • Itou, Shouetsu
    • Structural Engineering and Mechanics
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    • v.33 no.6
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    • pp.697-708
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    • 2009
  • Stresses are solved for two parallel cracks in an infinite orthotropic plate during passage of incoming shock stress waves normal to their surfaces. Fourier transformations were used to reduce the boundary conditions with respect to the cracks to two pairs of dual integral equations in the Laplace domain. To solve these equations, the differences in the crack surface displacements were expanded to a series of functions that are zero outside the cracks. The unknown coefficients in the series were solved using the Schmidt method so as to satisfy the conditions inside the cracks. The stress intensity factors were defined in the Laplace domain and were inverted numerically to physical space. Dynamic stress intensity factors were calculated numerically for selected crack configurations.

The Optimal Release Time in Cost Model Using PCLS Model

  • Song, Kwang Yoon;Chang, In Hong;Choi, Min Su;Lee, Da Hye
    • Journal of Integrative Natural Science
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    • v.9 no.3
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    • pp.206-214
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    • 2016
  • The basic goal of software development is to produce high quality software at low cost. Therefore, when to stop software testing and release the software product is a significant point in the software development. The software cost model is an effective tool used to help software developers control costs and determine the release time. In this paper, we discuss the cost model to apply all 6 models with consideration of time to remove errors, cost of removing each error and risk cost due to software failure. We show the impact of cost coefficients and parameter values on the expected total cost by changing the values and comparing the optimal release times.

Study on the Breakdown Simulation for InAlAs/InGaAs/GaAs MHEMTs with an InP-etchstop Layer (InP 식각정지층을 갖는 InAlAs/InGaAs/GaAs MHEMT 소자의 항복 특성 시뮬레이션에 관한 연구)

  • Son, Myung Sik
    • Journal of the Semiconductor & Display Technology
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    • v.11 no.2
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    • pp.53-57
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    • 2012
  • This paper is for accurately simulating the breakdown of MHEMTs with an InP-etchstop layer. 2D-Hydrodynamic simulation parameters are investigated and calibrated for the InP-epitaxy layer. With these calibrated parameters, simulations are performed and analyzed for the breakdown of devices with an InP-etchstop layer. In the paper, the impact-ionization coefficients, the mobility degradation due to doping concentration, and the saturation velocity for InP-epitaxy layer are newly calibrated for more accurate breakdown simulation.