• Title/Summary/Keyword: Matrix coefficients

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Development and Psychometric Testing of the Clinical Nursing Competency Scale for Clinical Preceptor Use (CNCS-CP) (임상간호실습 현장지도자용 임상간호역량 평가도구 개발)

  • Kwak, Eunmi;Oh, Heeyoung
    • Journal of Korean Academy of Nursing
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    • v.48 no.4
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    • pp.419-431
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    • 2018
  • Purpose: The purpose of this study was to develop and establish the psychometric properties of a clinical nursing competency evaluation tool to be utilized by clinical preceptors. Methods: The initial items were identified through in-depth literature review and field interviews based on a hybrid model. Content validation of the items was evaluated through three rounds of content validity testing. Participants were 34 clinical preceptors and 443 nursing students participating in clinical practice. Data were analyzed using exploratory and confirmatory factor analysis, convergence and discriminant validity, internal consistency and inter-rater reliability. Results: The final scale consisted of 23 items and four factors, fundamental nursing skills performance, critical thinking skills based on the nursing process, basic nursing knowledge, and professional attitude; these factor explained 69.7% of the total variance. The analysis with multi-trait/multi-item matrix correlation coefficients yielded 100.0% and 95.7 % convergence and discriminant validity, respectively. Cronbach's alpha for the total items was .95. The four subscale model tested by confirmatory factor analysis was satisfactory. Inter-rater reliability ranged from .912 to .967. Conclusion: This scale was found to be a reliable and valid instrument that clinical preceptors can apply for evaluating the clinical nursing competency of nursing students in clinical settings.

Hydroelastic Responses for a Ship Advancing in Waves (파랑중 전진하는 선박의 유탄성 응답)

  • 이호영;임춘규;정형배
    • Journal of the Society of Naval Architects of Korea
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    • v.40 no.4
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    • pp.16-21
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    • 2003
  • The very large container ships have been built recently and those ships have very small structural rigidity compared with the other conventional ships. As a result, the destruction of ship hull is occurred by the springing including to warping phenomena due to encounter waves. In this study, the solutions of hydrodynamic coefficients are obtained by solving the three dimensional source distribution method and the forward speed Green function representing a translating and pulsating source potential for infinite water depth is used to calculating the integral equation. The vessel is longitudinally divided into various sections and the added mass, wave damping and wave exciting forces of each section is calculated by integrating the dynamic pressures over the mean wetted section surface. The equations for six degree freedom of motions is obtained for each section in the frequency domain and stiffness matrix is calculated by Euler beam theory. The computations are carried out for very large ship and effects of bending and torsional ridigity on the wave frequency and angle are investigated.

Load Carrying Capacity due to Cracking Damage of Ellipsoidal Inhomogeneity in Infinite Body under Pure Shear and Its Elastic Stress Distributions (전단응력하의 무한체내 타원체불균질물의 균열손상에 따른 하중부하능력과 탄성응력분포)

  • 조영태;임광희;고재용;김홍건
    • Proceedings of the Korean Society For Composite Materials Conference
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    • 2001.10a
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    • pp.87-90
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    • 2001
  • In particle or short-fiber reinforced composites, cracking of the reinforcements is a significant damage mode because the broken reinforcements lose load carrying capacity. This paper deals with elastic stress distributions and load carrying capacity of intact and cracked ellipsoidal inhomogeneities. Three dimensional finite element analysis has been carried out on intact and broken ellipsoidal inhomogeneities in an infinite body under pure shear. For the intact inhomogeneity, as well known as Eshelby(1957) solution, the stress distribution is uniform in the inhomogeneity and non-uniform in the surrounding matrix. On the other hand, for the broken inhomogeneity, the stress in the region near crack surface is considerably released and the stress distribution becomes more complex. The average stress in the inhomogeneity represents its load carrying capacity, and the difference of average stresses between the intact and broken inhomogeneities indicates the loss of load carrying capacity due to cracking damage. The load carrying capacity of the broken inhomogeneity is expressed in terms of the average stress of the intact inhomogeneity and some coefficients. It is found that the broken inhomogeneity with higher aspect ratio still maintains higher load carrying capacity.

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Simultaneous Quantification of Sulfonamide and Tetracyclines in Fish Muscle Tissue by Matrix Solid Phase Dispersion (MSPD) Extraction and HPLC (MSPD와 HPLC를 이용한 어류의 잔류 설파제와 테트라사이클린계 항생물질의 동시분석)

  • 하대식;김종수;김곤섭
    • Journal of Food Hygiene and Safety
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    • v.12 no.2
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    • pp.117-124
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    • 1997
  • A simple, rapid and simultaneous analytical method is described for the detection of Sulfonamide and Tetracycline residues, i.e., Sulfamerazine (SMR), Sulfamethazine (SMT), Sulfamonomethoxine (SMM), Sulfadimethoxine (SDM), Sulfaquinoxaline (SQN), Oxytetracycline (OXY), Tetracycline (TC), Chlortetracycline (CTC). Blank control and sulfonamide and tetracycline fortified fish muscle samples (0.5 f) were blended with octadecylsilyl (C18, 40 ${\mu}{\textrm}{m}$, 21% load, 60$\AA$) derivatized silica packing material (2 g). Blended fish samples were washed with hexane, then, benzene and dichloromethace were used for the elution of tetracycline and sulfonamide were analyzed by HPLC. Correlation coefficients of standard curves for individual sulfonamide and tetracycline isolated from fortified samples were linear (0.9993$\pm$0.0003~0.9997$\pm$0.0003, 0.9493$\pm$0.078~0.9753$\pm$0.036), respectively. The average percentage recoveries of sulfonamide and tetracycline ranged as 80.86~96.52% to 85.88~92.23%, and 30.01~37.12% to 65.89~73.40%, for the concentration range (0.1~1.0 ppm) examined, respectively. Limit of detection for sulfonamide was 0.0012 ppm for SMR in Paralichthys Olivacleus and 0.0020 ppm for SMR, 0.015 ppm for SMM in Cyprinus Carpio. The applicability of this procedure is demonstrated by separation and detection of incurred tetracycline and sulfonamide residues in fish muscle tissue.

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Firework plot for evaluating the impact of influential observations in multi-response surface methodology (다반응 반응표면분석에서 특이값의 영향을 평가하기 위한 불꽃그림)

  • Kim, Sang Ik;Jang, Dae-Heung
    • The Korean Journal of Applied Statistics
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    • v.31 no.1
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    • pp.97-108
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    • 2018
  • It has been routine practice in regression analysis to check the validity of the assumed model by the use of regression diagnostics tools. Outliers and influential observations often distort the regression output in an undesired manner. Jang and Anderson-Cook (Quality and Reliability Engineering International, 30, 1409-1425, 2014) proposed a graphical method (called a firework plot) so that there could be an exploratory visualization of the trace of the impact of the possible outliers and influential observations on individual regression coefficients and the overall residual sum of the squares measure. This paper further extends a graphical approach to a multi-response surface methodology problem.

Carbon Emission Analysis Considering Demand Response Effect in TOU Program (TOU 프로그램의 DR 효과를 고려한 탄소 배출 분석)

  • Kim, Young-Hyun;Kwag, Hyung-Geun;Kim, Jin-O
    • The Transactions of The Korean Institute of Electrical Engineers
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    • v.60 no.6
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    • pp.1091-1096
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    • 2011
  • Currently, the concern about the environment is the issue all over the world, and in particular, carbon emissions of the power plants will not be able to disregard from the respect of generation cost. This paper proposes DR (demand response) as a method of reducing carbon emissions and therefore, carbon emissions cost. There are a number of studies considering DR, and in this paper, the effect of DR is focused on the side of carbon emission reduction effect considering Time-Of-Use (TOU) program, which is one of the most important economic methods in DSM. Demand-price elasticity matrix is used in this paper to model and analyze DR effect. Carbon emissions is calculated by using the carbon emission coefficient provided by IPCC (Intergovernmental Panel on Climate Change), and generator's input-output characteristic coefficients are also used to estimate carbon emission cost as well as the amount of carbon emissions. Case study is conducted on the RBTS IEEE with six buses. For the TOU program, it is assumed that parameters of time period partition consist of three time periods (peak, flat, off-peak time period).

An Analysis and Evaluation of the Effectiveness of Decision Making During the Review of Scientifically Constructed Project Proposals

  • Abdykerova, G.Zh;Bukayeva, A.D.
    • Asia-Pacific Journal of Business Venturing and Entrepreneurship
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    • v.3 no.2
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    • pp.31-44
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    • 2008
  • A selection technique for innovative projects on the beginning stage has been presented in this article. It can be applied in projects assessment in HEI, enterprises, development institutes, etc. It is rather difficult to assess the project quality on the beginning stage of R&D due to the uncertainty in the technical and economic indices but the new development analysis on this stage is of a great interest. By innovative project quality as a management object we will mean those characteristics relating to the results capacity of the projects and its realization process to satisfy the requirements to the innovative products competitiveness and their innovative attractiveness for investors. The most important question in the innovative projects management is the determination of its quality level under modern conditions. The aim of the research is to analyze and evaluate the decision making during the project management process. The objectives and hypotheses are assessment of an innovative project with the application of McKinsey's model is better to realizes by 3 stages: a) selection of optimal criteria; b) determination of weighing coefficients; c) projects positioning in a matrix.

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A Numerical Analysis of Convective Heat Transfer in Air Flow Channels of a Plate Fin-tube Matrix for Heat Pipe Heat Sinks (히트파이프 히트싱크에서 평판 휜-관으로 구성된 공기유동 냉각채널의 대류 열전달 특성에 관한 수치해석)

  • Kim Sung-Hoon;Shin Hyun-Myung;Kim Chul-Ju
    • Journal of Advanced Marine Engineering and Technology
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    • v.29 no.8
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    • pp.862-869
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    • 2005
  • A study on convective cooling characteristics has been done in the channels with heat pipes and associated Plane fins Analysis with FLUENT V5.0 lies its Purpose on the possible enhancement of heat transfer capability between an existing three in-line arrayed heatpipes and an extending four in-line arrayed heatpipes with increasing channel width. Numerical analysis is limited to the laminar flow in an isolated flow channel by employing cyclic boundary conditions for calculation purposes. Friction factors for three and four in-line arrayed heatpipes are compared with experimental results. In addition, temperature behavior at the plate fin for the three in-line arrayed heatpipes is compared with experiment. Friction factors and overall channel heat transfer coefficients (and/or Nusselt numbers) are presented as a function of Reynolds number. An increase of number of heatpipes and channel width reults in a decrease of the friction factor and doesn't not result in an increase of heat transfer performance. However. considering the 25$\%$ increase of heat load accompanies with maximum 8$^{\circ}C$ rise of average temperature of heat pipes, the four in-line array with the increase of channel width of heat pipe heat sink can be considered appropriate.

An Experimental Study on the Static and Dynamic Characteristics of High Speed Air Foil Bearings (고속 공기 포일 베어링의 정적${\cdot}$동적 특성에 관한 실험적 연구)

  • Jo Jun-Hyeon;Lee Yong-Bok;Kim Chang-Ho;Rhim Yoon-Chul
    • Proceedings of the Korean Society of Tribologists and Lubrication Engineers Conference
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    • 2004.11a
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    • pp.186-194
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    • 2004
  • Experiments were conducted to determine the structural static and dynamic characteristics of air foil bearings. The housing of the bearing on the journal was driven by an impact hammer which was used to simulate dynamic forces acting on the bump loll with various leading condition. Two different bump foils (Cu-coated bump and viscoelastic bump) were tested and the static and dynamic coefficients of two bump foils compared, based on the experimental measurements for a wide range of operating conditions. The static and dynamic characteristics of air foil bearings were extracted 0rpm the frequency response function by least square method and IV(Instrumental Variable) method. The experiment was tested at 0rpm and $10,000\~16,000rpm$, and loaded on $50\~150N$. From the test results, the possibility of the application of high load and high speed condition is suggested.

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Vibration analysis of sandwich sectorial plates considering FG wavy CNT-reinforced face sheets

  • Tahouneh, Vahid
    • Steel and Composite Structures
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    • v.28 no.5
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    • pp.541-557
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    • 2018
  • This paper presents the influence of carbon nanotubes (CNTs) waviness and aspect ratio on the vibrational behavior of functionally graded nanocomposite sandwich annular sector plates resting on two-parameter elastic foundations. The carbon nanotube-reinforced (CNTR) sandwich plate has smooth variation of CNT fraction along the thickness direction. The distributions of CNTs are considered functionally graded (FG) or uniform along the thickness and their mechanical properties are estimated by an extended rule of mixture. In this study, the classical theory concerning the mechanical efficiency of a matrix embedding finite length fibers has been modified by introducing the tube-to-tube random contact, which explicitly accounts for the progressive reduction of the tubes' effective aspect ratio as the filler content increases. Effects of CNT distribution, volume fraction, aspect ratio and waviness, and also effects of Pasternak's elastic foundation coefficients, sandwich plate thickness, face sheets thickness and plate aspect ratio are investigated on the free vibration of the sandwich plates with wavy CNT-reinforced face sheets. The study is carried out based on three-dimensional theory of elasticity and in contrary to two-dimensional theories, such as classical, the first- and the higher-order shear deformation plate theories, this approach does not neglect transverse normal deformations. The sandwich annular sector plate is assumed to be simply supported in the radial edges while any arbitrary boundary conditions are applied to the other two circular edges including simply supported, clamped and free.