• Title/Summary/Keyword: cross sectional study

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Analysis of the Image and Likability of the Nurse (간호사의 이미지와 호감도 분석)

  • Yom, Young-Hee;Kim, Kyunghee;Son, Heesook;Jeon, Jae-Hee;Lee, Jungmin;Kim, Myoung Ae
    • Journal of Korean Clinical Nursing Research
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    • v.21 no.2
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    • pp.169-179
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    • 2015
  • Purpose: The purpose of this study was to investigate nurse images and likability that were perceived by various groups in the general population. Methods: Using cross-sectional descriptive design, six groups of people were invited to participate in the survey. The participants included nurses, physicians, nurse aids/technicians, patients/caregivers, college students, and the general public. A total of 1,530 individuals were drawn from 42 hospitals nationwide. Bhargava's likability questionnaires and the Ward Nurse Image tool were used. Results: Compared with other groups, patients and caregivers had higher scores for likability and better nurse image than other groups. Most respondents perceived nurses are clean and caring, but many individuals still had the image that nurses are submissive. Conclusion: To improve nurse image, perceptions from various groups of people need to be considered and programs develop to show the positive aspects of nursing and nurses.

Bending Characteristic Evaluations Circular Cross-section Carbon Composite and Hybrid Structural Material (원통단면 탄소복합재와 혼성 구조부재의 굽힘 특성 평가)

  • Kim, Jung-Ho;Jeong, Jong-An;Kim, Ji-Hoon
    • Journal of the Korean Society of Manufacturing Technology Engineers
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    • v.21 no.3
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    • pp.421-424
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    • 2012
  • Carbon Fiber reinforced composite material can be designed for the optimized performances of structural member that have achieve appropriate mechanical properties with cross-sectional shape, fiber direction, stacking sequence and thickness. So there are needed extensive databases each optimal design of CFRP structural member by impact through the preparation of different shape, interface number, thickness and stacking angle. When pressure is applied to structural member, compression, bending and torsion is shown on the corresponding member. For the effective utilization of fiber reinforced composite material as main structural member, optimized design technology should be established to maximize mechanical properties for compression, bending and torsion. In this paper, CFRP prepreg sheet with different stacking angle is manufactured in CFRP and hybrid(Al+CFRP) with circular cross-section. Strength and stiffness is gotten respectively by flexure test. CFRP structure and hybrid structure can be compared with each other. The best design guideline can be analyzed by use of this study result.

Experimental and numerical study on generation and mitigation of vortex-induced vibration of open-cross-section composite beam

  • Zhou, Zhiyong;Zhan, Qingliang;Ge, Yaojun
    • Wind and Structures
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    • v.23 no.1
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    • pp.45-57
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    • 2016
  • Open-cross-section composite beam (OCB) tends to suffer vortex-induced vibration (VIV) due to its bluff aerodynamic shape. A cable-stayed bridge equipped with typical OCB is taken as an example in this paper to conduct sectional model wind tunnel test. Vortex-induced vibration is observed and maximum vibration amplitudes are obtained. CFD approach is employed to calculate the flow field around original cross sections in service stage and construction stage, as well as sections added with three different countermeasures: splitters, slabs and wind fairings. Results show that flow separate on the upstream edge and cause vortex shedding on original section. Splitters can only smooth the flow field on the upper surface, while slabs cannot smooth flow field on the upper or lower surface too much. Thus, splitters or slabs cannot serve as valid aerodynamic means. Wind tunnel test results show that VIV can only be mitigated when wind fairings are mounted, by which the flow field above and below the bridge deck are accelerated simultaneously.

Determination of the Static Rigidity of the End Mill Using Neural Network (신경망을 이용한 엔드밀의 정적 강성 결정)

  • Lee, Sang-Kyu;Ko, Sung-Lim
    • Journal of the Korean Society for Precision Engineering
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    • v.14 no.12
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    • pp.143-152
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    • 1997
  • The deflection of an end mill is very important in machining process and cutting simulation because it affects directly workpiece accuracy, cutting force, and chattering. In this study, the deflection of the end mill was studied both experimentally and by using finite element analysis. And the moment of inertia of cross sections of the helical end mill is calculated for the determination of the relation between geometry of radial cross section and rigidity of the tools. Using the Bernoulli-Euler beam theory and the concept of equivalent diameter, a deflection model is established, which includes most influences from tool geomety parameters. It was found that helix angle attenuates the rigidity of the end mill by the finite element analysis. As a result, the equivalent diameter is determined by tooth number, inscribed diameter ratio, cross sectional geometry and helix angle. Because the relation betweem equivalent diameter and each factor is nonlinear, neural network is used to decide the equivalent diameter. Input patterns and desired outputs for the neural network are obtained by FEM analysis in several case of end milling operations.

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Studies on Effects of Deposition Parameters in Manufacturing of C/Sic composites by Pulse-CVI (C/SiC 복합재료 제조시 Pulse-CVI에서 증착변수의 영향 연구)

  • 김용탁;김영준;정귀영
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.141-143
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    • 2001
  • Ceramic fiber-reinforced composites have good mechanical properties in hardness and durability. In this study, we studied the formation of SiC/C composites from methyltrichlorosilane and hydrogen by the Pulse-chemical vapor infiltration(PCVI) to deposit silicon carbide around the changes of the amount of deposit. SiC/C composites formed at $950^{\circ}C$, 20torr, Pulse-times (5s/60s). SEM of the cross sectional area of semple showed deposited silicon carbide around fibers.

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Torsional Elastic Waves Propagating in a Periodically-Nonuniform Circular Rod (주기적으로 불균일한 원형막대에서 전파하는 비틂 탄성파)

  • 김진오
    • Proceedings of the Acoustical Society of Korea Conference
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    • 1998.06c
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    • pp.323-326
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    • 1998
  • The paper describes a theoretical and experimental study on the speed of the torsional elastic waves propagating in an axisymmetirc waveguide whose cross-sectional area varies periodically as an harmonic function of the axial coordinate. The approximate solution of the phase speed has been obtained using the perturbation technique for sinusoidal modulation of small amplitude. The experiment verifying the theoretical result consists of transmitting and receiving torsional waves by magnetostriction and measuring the wave speed in the waveguides with threaded surfaces.

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A Study on the Sound Absorption Coefficient by Varying Sample Size (시편의 크기에 따른 흡음계수 변화 연구)

  • 정성수;이우섭;조문재;서상준
    • Transactions of the Korean Society for Noise and Vibration Engineering
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    • v.11 no.5
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    • pp.83-88
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    • 2001
  • The sound absorption coefficient of glass wool (bulk density of 48 kg/m:1 and 32 kg/m7) was measured by reverberation room method as varying their cross-sectional area. The results show that the absorption is larger for smaller samples because of edge effect. The absorption coefficient with two different kinds of sources. 1/.7-octave band and while noise, gives similar values.

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A Study on the Structural Design in Automatic Transport System (자동반송장치의 구조설계에 관한 연구)

  • 김홍건
    • Proceedings of the Korean Society of Machine Tool Engineers Conference
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    • 1998.03a
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    • pp.258-262
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    • 1998
  • A structural design based of finite element analysis has been performed to investigate the reliable automatic transport system. For the procedure, different cross-sectional geometric factors were calculated and compared in detail. The von-Mises stresses were chosen to maintain a solid loading braring capacity for the safe design. Parametric studies showed that it is more inportant for the plate bending problem than the vertical loads of hanging bar to assess the safe and economic structural design.

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Buckling optimization of compressed bars undergoing corrosion

  • Fridman, Mark M.;Elishakoff, Isaac
    • Ocean Systems Engineering
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    • v.3 no.2
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    • pp.123-136
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    • 2013
  • This study is devoted to the optimal design of compressed bars under axial compressive forces and exposed to a corrosive environment. The initial volume of the structure is taken as an optimality parameter. Gutman - Zainullin's exponential stress corrosion model is adopted for analysis. Analytical and numerical results are derived for optimal variation of the cross-sectional area of the bar along its axis.