• Title/Summary/Keyword: the refined model

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A Statistical Model for Marker Position in Biomechanics

  • Kim, Jinuk
    • Korean Journal of Applied Biomechanics
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    • v.27 no.1
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    • pp.67-74
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    • 2017
  • Objective: The purpose of this study was to apply a general linear model in statistics to marker position vectors used to study human joint rotational motion in biomechanics. Method: For this purpose, a linear model that represents the effect of the center of hip joint rotation and the rotation of the marker position on the response was formulated. Five male subjects performed hip joint functional motions, and the positions of nine markers attached on the thigh with respect to the pelvic coordinate system were acquired at the same time. With the nine marker positions, the center of hip joint rotation and marker positions on the thigh were estimated as parameters in the general linear model. Results: After examining the fitted model, this model did not fit the data appropriately. Conclusion: A refined model is required to take into account specific characteristics of longitudinal data and other covariates such as soft tissue artefacts.

A Study on the Development of Cooperative Clinical Nursing Education Model (산학공조형(Co-op) 간호실습교육 운영모형 개발)

  • Cho, Kap-Chul;Boo, Eun-Hee;Roh, Young-Sook
    • The Journal of Korean Academic Society of Nursing Education
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    • v.11 no.2
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    • pp.127-134
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    • 2005
  • Purpose: The purpose of the study was to develop a cooperative clinical nursing education model in response to the challenge to provide quality clinical instruction for nursing students. Method: A hypothesized model was developed based on literature review and Cho's partnership model of preservice teacher. Final model was refined with cooperative committee meetings, workshop and post clinical education meetings. Results: A Cooperative clinical nursing education model was developed with three phases(collaboration, planning, redefinition of major roles) and ten constructs(organization of cooperative committee, goal setting, partnership contract, planning objectives, and operating manual). Conclusion: The Cooperative clinical nursing education model support the need for continued collaborative partnership between nursing college and hospitals to foster quality clinical instruction.

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Damage and vibrations of nuclear power plant buildings subjected to aircraft crash part II: Numerical simulations

  • Li, Z.R.;Li, Z.C.;Dong, Z.F.;Huang, T.;Lu, Y.G.;Rong, J.L.;Wu, H.
    • Nuclear Engineering and Technology
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    • v.53 no.9
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    • pp.3085-3099
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    • 2021
  • Investigations of large commercial aircraft impact effect on nuclear power plant (NPP) buildings have been drawing extensive attentions, particularly after the 9/11 event, and this paper aims to numerically assess the damage and vibrations of NPP buildings subjected to aircrafts crash. In Part I of present paper, two shots of reduce-scaled model test of aircraft impact on NPP were conducted based on the large rocket sled loading test platform. In the present part, the numerical simulations of both scaled and prototype aircraft impact on NPP buildings are further performed by adopting the commercial program LS-DYNA. Firstly, the refined finite element (FE) models of both scaled aircraft and NPP models in Part I are established, and the model impact test is numerically simulated. The validities of the adopted numerical algorithm, constitutive model and the corresponding parameters are verified based on the experimental NPP model damages and accelerations. Then, the refined simulations of prototype A380 aircraft impact on a hypothetical NPP building are further carried out. It indicates that the NPP building can totally withstand the impact of A380 at a velocity of 150 m/s, while the accompanied intensive vibrations may still lead to different levels of damage on the nuclear related equipment. Referring to the guideline NEI07-13, a maximum acceleration contour is plotted and the shock damage propagation distances under aircraft impact are assessed, which indicates that the nuclear equipment located within 11.5 m from the impact point may endure malfunction. Finally, by respectively considering the rigid and deformable impacts mainly induced by aircraft engine and fuselage, an improved Riera function is proposed to predict the impact force of aircraft A380.

The Leadership Core-Value of the Muaesabang(無碍四方, Intercommunication) (무애사방(無碍四方)의 리더십 핵심가치)

  • Ahn, Eun-Soo
    • The Journal of Korean Philosophical History
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    • no.23
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    • pp.67-97
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    • 2008
  • In this paper, I found the leadership core-value of the Sunbai(선배) a man of refined taste. I studied twelve Sunbai considered as a man of refined taste in this research. I focused on the aspect showing common worth among their various abilities and cultural contributions, a point of view of classifying them into one form called Sunbai a man of refined taste. As the core value is the basis of supporting the individual identity, so the leadership core-value is the source and philosophical base of displaying the leadership. Our Sunbai combining character and knowledge show common structure in their personal growth and showing the leadership. It is that they embodied the stage of cultivating themselves(修身, Self), considering the relation with others(齊家, Relation), leading the organization(治國, Team), and making efforts for and having influence on the community(平天下, Community) throughout their own life. I examined how to display the leadership in the four fields on a case by case basis and then constructed the leadership model of the Sunbai a man of refined taste by synthesizing them. As a result, I considered their leadership core-value as the intercommunication and named it 'Leadership of Muaesabang(無碍四方)'. Also, I confirmed that it is still very valuable in these days of aiming at the open society and the harmony of the diverse civilization.

Refinement of Protein NMR Structure under Membrane-like Environments with an Implicit Solvent Model

  • Jee, Jun-Goo;Ahn, Hee-Chul
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1139-1142
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    • 2009
  • Refinement of NMR structures by molecular dynamics (MD) simulations with a solvent model has improved the structural quality. In this study, we applied MD refinement with the generalized Born (GB) implicit solvent model to protein structure determined under membrane-like environments. Despite popularity of the GB model, its applications to the refinement of NMR structures of hydrophobic proteins, in which detergents or organic solvents enclose proteins, are limited, and there is little information on the use of another GB parameter for these cases. We carried out MD refinement of crambin NMR structure in dodecylphosphocholine (DPC) micelles (Ahn et al., J. Am. Chem. Soc. 2006, 128, 4398-4404) with GB/Surface area model and two different surface tension coefficients, one for aquatic and the other for hydrophobic conditions. Our data show that, of two structures by MD refinement with GB model, the one refined with the parameter to consider hydrophobic condition had the better qualities in terms of precision and solvent accessibility.

Stability analysis of porous multi-phase nanocrystalline nonlocal beams based on a general higher-order couple-stress beam model

  • Ebrahimi, Farzad;Barati, Mohammad Reza
    • Structural Engineering and Mechanics
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    • v.65 no.4
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    • pp.465-476
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    • 2018
  • This article investigates buckling behavior of a multi-phase nanocrystalline nanobeam resting on Winkler-Pasternak foundation in the framework of nonlocal couple stress elasticity and a higher order refined beam model. In this model, the essential measures to describe the real material structure of nanocrystalline nanobeams and the size effects were incorporated. This non-classical nanobeam model contains couple stress effect to capture grains micro-rotations. Moreover, the nonlocal elasticity theory is employed to study the nonlocal and long-range interactions between the particles. The present model can degenerate into the classical model if the nonlocal parameter, and couple stress effects are omitted. Hamilton's principle is employed to derive the governing equations and the related boundary conditions which are solved applying an analytical approach. The buckling loads are compared with those of nonlocal couple stress-based beams. It is showed that buckling loads of a nanocrystalline nanobeam depend on the grain size, grain rotations, porosities, interface, elastic foundation, shear deformation, surface effect, nonlocality and boundary conditions.

A Study on the Development of a Mathematics Teaching and Learning Model for Meta-Affects Activation (수학 교과에서 메타정의를 활성화하는 교수·학습 모델 개발)

  • Son, Bok Eun
    • East Asian mathematical journal
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    • v.38 no.4
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    • pp.497-516
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    • 2022
  • In this study, we tried to devise a method to activate meta-affect in the aspect of supporting mathematics teaching and learning according to the need to find specific strategies and teaching and learning methods to activate learners' meta-affect in mathematics subjects, which are highly influenced by psychological factors. To this end, the definitional and conceptual elements of meta-affect which are the basis of this study, were identified from previous studies. Reflecting these factors, a teaching and learning model that activates meta-affect was devised, and a meta-affect activation strategy applied in the model was constructed. The mathematics teaching and learning model that activates meta-affect developed in this study was refined by verifying its suitability and convenience in the field through expert advice and application of actual mathematics classes. The developed model is meaningful in that it proposed a variety of practical teaching and learning methods that activate the meta-affect of learners in a mathematical learning situation.

Communication-Theoretic Analysis of Capture-Based Networks

  • Nguyen, Gam D.;Wieselthier, Jeffrey E.;Ephremides, Anthony
    • Journal of Communications and Networks
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    • v.14 no.3
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    • pp.243-251
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    • 2012
  • Under the power-based capture model, a transmission is successfully received at the destination, even in the presence of other transmissions and background noise, if the received signal-to-interference-plus-noise ratio exceeds a capture threshold. We evaluate the spectral efficiency of simple multi-user channels by combining the basic capture model with a communication-theoretic model. The result is a more refined capture model that incorporates key system design parameters (such as achievable bit rate, target bit error rate, channel bandwidth, and modulation signal constellations) that are absent from the basic capture model. The relationships among these parameters can serve as a tool for optimizing the network performance.

Assessment of a concrete arch bridge using static and dynamic load tests

  • Caglayan, B. Ozden;Ozakgul, Kadir;Tezer, Ovunc
    • Structural Engineering and Mechanics
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    • v.41 no.1
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    • pp.83-94
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    • 2012
  • Assessment of a monumental concrete arch bridge with a total length of 210 meters having three major spans of 30 meters and a height of 65 meters, which is located in an earthquake-prone region in southern part of the country is presented in this study. Three-dimensional finite element model of the bridge was generated using a commercially available general finite element analysis software and based on the outcomes of a series of in-depth acceleration measurements that were conducted on-site, the model was refined. By using the structural parameters obtained from the dynamic and the static tests, calibrated model of the bridge structure was obtained and this model was used for necessary calculations regarding structural assessment and evaluation.

A refined quasi-3D theory for stability and dynamic investigation of cross-ply laminated composite plates on Winkler-Pasternak foundation

  • Nasrine Belbachir;Fouad Bourada;Abdelmoumen Anis Bousahla;Abdelouahed Tounsi;Mohamed A. Al-Osta;Mofareh Hassan Ghazwani;Ali Alnujaie;Abdeldjebbar Tounsi
    • Structural Engineering and Mechanics
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    • v.85 no.4
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    • pp.433-443
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    • 2023
  • The current paper discusses the dynamic and stability responses of cross-ply composite laminated plates by employing a refined quasi-3D trigonometric shear deformation theory. The proposed theory takes into consideration shear deformation and thickness stretching by a trigonometric variation of in-plane and transverse displacements through the plate thickness and assures the vanished shear stresses conditions on the upper and lower surfaces of the plate. The strong point of the new formulation is that the displacements field contains only 4 unknowns, which is less than the other shear deformation theories. In addition, the present model considers the thickness extension effects (εz≠0). The presence of the Winkler-Pasternak elastic base is included in the mathematical formulation. The Hamilton's principle is utilized in order to derive the four differentials' equations of motion, which are solved via Navier's technique of simply supported structures. The accuracy of the present 3-D theory is demonstrated by comparing fundamental frequencies and critical buckling loads numerical results with those provided using other models available in the open literature.