• Title/Summary/Keyword: Linear relations

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Differences between Perceived Readiness for Interprofessional Learning in Nursing and Other Health-related Students (간호학과와 타 보건의료관련 학과 학생들의 전문직 간 학습 준비도 차이)

  • Lee, Hyeonkyeong;Kim, In Sook;Lee, Tae Wha;Kim, Gwang Suk;Cho, Eunhee;Lee, Kyung Hee;Kim, Junghee
    • The Journal of Korean Academic Society of Nursing Education
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    • v.25 no.3
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    • pp.312-320
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    • 2019
  • Purpose: The purpose of this study was to investigate the level of perceived readiness for interprofessional learning and its differences between nursing and other health-related students. Methods: A web-based survey was conducted from April 25 to June 30, 2017 in one university in Korea. A total of 325 undergraduate nursing students and other health-related disciplines completed the structured questionnaire consisting of Readiness for Interprofessional Learning Scale and general characteristics. Data were analyzed by descriptive statistics, t-test, ANOVA, and multiple linear regression. Results: The scores of readiness for interprofessional learning in nursing students were significantly higher than those in other health-related students (t=3.50, p=.001). Nursing students had higher collaboration, professional identity, and roles and responsibilities than other health-related students. The class experiences with other major students was a significant factor related to the readiness for interprofessional learning both in nursing (p=.001) and other health-related students (p=.001). Conclusion: The findings suggest that nursing educators consider the different level of readiness for interprofessional learning between nursing and other health-related students while integrating interprofessional education into nursing education curricula.

Nonlinear thermoelastic analysis of FGM thick plates

  • Bouhlali, Malika;Chikh, Abdelbaki;Bouremana, Mohammed;Kaci, Abdelhakim;Bourada, Fouad;Belakhdar, Khalil;Tounsi, Abdelouahed
    • Coupled systems mechanics
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    • v.8 no.5
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    • pp.439-457
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    • 2019
  • In this paper, a new application of a four variable refined plate theory to analyze the nonlinear bending of functionally graded plates exposed to thermo-mechanical loadings, is presented. This recent theory is based on the assumption that the transverse displacements consist of bending and shear components in which the bending components do not contribute toward shear forces, and similarly, the shear components do not contribute toward bending moments. The derived transverse shear strains has a quadratic variation across the thickness that satisfies the zero traction boundary conditions on the top and bottom surfaces of the plate without using shear correction factors. The material properties are assumed to vary continuously through the thickness of the plate according to a power-law distribution of the volume fraction of the constituents. The solutions are achieved by minimizing the total potential energy. The non-linear strain-displacement relations in the von Karman sense are used to derive the effect of geometric non-linearity. It is concluded that the proposed theory is accurate and simple in solving the nonlinear bending behavior of functionally graded plates.

Comparative Study on Various Ductile Fracture Models for Marine Structural Steel EH36

  • Park, Sung-Ju;Lee, Kangsu;Cerik, Burak Can;Choung, Joonmo
    • Journal of Ocean Engineering and Technology
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    • v.33 no.3
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    • pp.259-271
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    • 2019
  • It is important to obtain reasonable predictions of the extent of the damage during maritime accidents such as ship collisions and groundings. Many fracture models based on different mechanical backgrounds have been proposed and can be used to estimate the extent of damage involving ductile fracture. The goal of this study was to compare the damage extents provided by some selected fracture models. Instead of performing a new series of material constant calibration tests, the fracture test results for the ship building steel EH36 obtained by Park et al. (2019) were used which included specimens with different geometries such as central hole, pure shear, and notched tensile specimens. The test results were compared with seven ductile fracture surfaces: Johnson-Cook, Cockcroft-Latham-Oh, Bai-Wierzbicki, Modified Mohr-Coulomb, Lou-Huh, Maximum shear stress, and Hosford-Coulomb. The linear damage accumulation law was applied to consider the effect of the loading path on each fracture surface. The Swift-Voce combined constitutive model was used to accurately define the flow stress in a large strain region. The reliability of these simulations was verified by the good agreement between the axial tension force elongation relations captured from the tests and simulations without fracture assignment. The material constants corresponding to each fracture surface were calibrated using an optimization technique with the minimized object function of the residual sum of errors between the simulated and predicted stress triaxiality and load angle parameter values to fracture initiation. The reliabilities of the calibrated material constants of B-W, MMC, L-H, and HC were the best, whereas there was a high residual sum of errors in the case of the MMS, C-L-O, and J-C models. The most accurate fracture predictions for the fracture specimens were made by the B-W, MMC, L-H, and HC models.

Investigating wave propagation in sigmoid-FGM imperfect plates with accurate Quasi-3D HSDTs

  • Mokhtar Nebab;Hassen Ait Atmane;Riadh Bennai
    • Steel and Composite Structures
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    • v.51 no.2
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    • pp.185-202
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    • 2024
  • In this research paper, and for the first time, wave propagations in sigmoidal imperfect functionally graded material plates are investigated using a simplified quasi-three-dimensionally higher shear deformation theory (Quasi-3D HSDTs). By employing an indeterminate integral for the transverse displacement in the shear components, the number of unknowns and governing equations in the current theory is reduced, thereby simplifying its application. Consequently, the present theories exhibit five fewer unknown variables compared to other Quasi-3D theories documented in the literature, eliminating the need for any correction coefficients as seen in the first shear deformation theory. The material properties of the functionally graded plates smoothly vary across the cross-section according to a sigmoid power law. The plates are considered imperfect, indicating a pore distribution throughout their thickness. The distribution of porosities is categorized into two types: even or uneven, with linear (L)-Type, exponential (E)-Type, logarithmic (Log)-Type, and Sinus (S)-Type distributions. The current quasi-3D shear deformation theories are applied to formulate governing equations for determining wave frequencies, and phase velocities are derived using Hamilton's principle. Dispersion relations are assumed as an analytical solution, and they are applied to obtain wave frequencies and phase velocities. A comprehensive parametric study is conducted to elucidate the influences of wavenumber, volume fraction, thickness ratio, and types of porosity distributions on wave propagation and phase velocities of the S-FGM plate. The findings of this investigation hold potential utility for studying and designing techniques for ultrasonic inspection and structural health monitoring.

Prediction of Seasonal Nitrate Concentration in Springs on the Southern Slope of Jeju Island using Multiple Linear Regression of Geographic Spatial Data (지리 공간 자료의 다중회귀분석을 이용한 제주도 남측사면 용천수의 시기별 질산성 질소 농도 예측)

  • Jung, Youn-Young;Koh, Dong-Chan;Kang, Bong-Rae;Ko, Kyung-Suk;Yu, Yong-Jae
    • Economic and Environmental Geology
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    • v.44 no.2
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    • pp.135-152
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    • 2011
  • Nitrate concentrations in springs at the southern slope of Jeju Island were predicted using multiple linear regression (MLR) of spatial variables including hydrogeological parameters and land use characteristics. Springs showed wide range of nitrate concentrations from <0.02 to 86 mg/L with a mean of 20 mg/L. Spatial variables were generated for the circular buffer when the optimal buffer radius was assigned as 400 m. Selected regression models were tested using the p values and Durbin-Watson statistics. Explanatory variables were selected using the adjusted $R^2$, Cp (total squared error) and AIC (Akaike's Information Criterion), and significance. In addition, mutual linear relations between variables were also considered. Small portion of springs, usually <10% of total samples, were identified as outliers indicating limitations of MLR using circular buffers. Adjusted $R^2$ of the proposed models was improved from 0.75 to 0.87 when outliers were eliminated. In particular, the areal proportion of natural area had the greatest influence on the nitrate concentrations in springs. Among anthropogenic land uses, the influence of nitrate contamination is diminishing in the following order of orchard, residential area, and dry farmland. It is apparent quality of springs in the study area is likely to be controlled by land uses instead of hydrogeological parameters. Most of all, it is worth highlighting that the contamination susceptibility of springs is highly sensitive to nearby land uses, in particular, orchard.

Geochemistry of Granites in the Southern Gimcheon Area of Korea (김천남부에 분포하는 화강암류의 지구화학)

  • 윤현수;홍세선
    • The Journal of the Petrological Society of Korea
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    • v.12 no.1
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    • pp.16-31
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    • 2003
  • The granites in the southern Gimcheon area can be divided into two parts, marginal hornblende biotite granodiorite (Mgd) and central biotite granodiorite to granite (Cgd). Mgd and Cgd are gray in color and display gradational contact relations and are mainly composed of coarse-grained and medium-grained rocks, respectively. Mgd has more frequent and larger mafic enclaves than Cgd, and the two granites partly show parallel foliation at thire contact with gneisses. From representative samples of the granites, K-Ar biotite ages of 197∼207 Ma were obtained. Considering the blocking temperature of biotite, it is suggested that the emplacement age of the granitic magma was probably late Triassic. The anorthite contents of plagioclases in Mgd display less variation than those of Cgd, indicating that Mgd crystallized within a narrow range of temperatures. In the Al$\_$total/-Mg diagram, the biotites from the granites plot within the subalkaline field, and the smooth slope indicates differentiation from a single magma. All amphiboles from the granites belong to magnesio-hornblende. The linear trends of major oxides, AFM and Ba-Sr-Rb indicate that Mgd and Cgd were fractionally differentiated from a single granitic magma body crystallizing from the margin inwards. The relations of modal (Qz+Af) vs. Op, K$_2$O vs. Na$_2$O, Fe$_2$ $O_3$ vs. FeO, Fe$\^$+3/(Fe$\^$+3/+Fe$\^$+2/) and K/Rb vs. Rb/Sr show that they belong to I-type and magnetite-series granitic rocks developed by the progressive melting products of fixed sources. REE data, normalized to chondrite value, have trends of enriched LREE and depleted HREE together with weakly negative Eu anomalies.

Temporal Dynamics of Water Quality in Junam Reservoir, as a Nest of Migratory Birds (철새도래지인 주남저수지의 계절적 수질변동)

  • Lee, Eui-Haeng;An, Kwang-Guk
    • Korean Journal of Ecology and Environment
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    • v.42 no.1
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    • pp.9-18
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    • 2009
  • The objectives of this study were to evaluate seasonal and interannual variations of water quality and nutrient input (N, P) in Junam Reservoir, a nesting waterbody of migratory birds, over 10 years during 1998$\sim$2007 along with dynamic relations of trophic parameters using empirical models. Concentrations of COD averaged 7.8 mg $L^{-1}$ during the study, while TN and TP were $1.4\;mg\;L^{-1}$ and $83{\mu}g\;L^{-1}$, respectively, indicating an eutrophic-hypereutrophic state. Values of monthly COD had strong positive relations (r=0.669, p<0.001) with conductivity, indicating that summer rainfall resulted in an ionic dilution of the reservoir water by rainwater and contributed better water quality. One-way ANOVA tests showed significant differences (F=$5.2{\sim}12.9$, p<0.05) in TN and TP between the before and after the bird migration. In other words, nutrient levels were greater in the absence of migratory birds than in the presence of the migratory birds, suggesting a no-effect on nutrient inputs by the birds. Also, one-way ANOVA indicated no significant differences (F=$0.37{\sim}0.48$, p>0.05) in $NO_{3^-}N$ and $NH_{3^-}N$ between the before and after the birds migration. Linear empirical models using trophic parameters showed that algal biomass as CHL, had significant low correlations with TN ($R^2$=0.143, p<0.001, n=119) and TP ($R^2$=0.192, p<0.001, n=119). These results suggest that influences of nutrients on the CHL were evident, but the effect was weak. This fact was supported by analysis of Trophic State Index Deviation (TSID). Over 70% in the observed values of "TSI (CHL)-TSI (SD)" and "TSI (CHL)-TSI (TP)" were less than zero, suggesting a light limitation on the CHL by inorganic suspended solids.

An empirical study on the impact of academic competitions on innovation and entrepreneurship among Chinese university students (학술 경연대회가 중국 대학생들의 혁신과 기업가 정신에 미치는 영향에 대한 실증적 연구)

  • Jinling Wang;Ning Wang
    • Journal of the International Relations & Interdisciplinary Education
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    • v.3 no.1
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    • pp.51-75
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    • 2023
  • Relying on disciplinary competitions to enhance college students' innovation and entrepreneurship is one of the specific paths to explore the reform of innovation and entrepreneurship education in colleges and universities. This paper conducts an empirical study on the practice of disciplinary competitions among Chinese university students, the problems of innovation and entrepreneurship education in Chinese universities and the impact of disciplinary competitions on innovation and entrepreneurship among Chinese university students, using university students in Chinese universities as the respondents. The data collected online and offline were analysed using SPSS26 statistical software. The results of the analysis show that Chinese university students show a high level of interest in innovation and entrepreneurship competitions and that there are some differences in the level of interest in innovation and entrepreneurship competitions among university students of different academic levels. More than half of Chinese university students have participated in innovation and entrepreneurship competitions and the initiative of participating in innovation and entrepreneurship competitions varies by grade. The biggest problem facing innovation and entrepreneurship education in schools is the lack of professional innovation and entrepreneurship teachers, followed by the lack of guidance on innovation and entrepreneurship-related policies, and the unreasonable reward system, which makes teachers and students less motivated to innovate and entrepreneurship. Through one-dimensional linear regression analysis, it is found that the degree of attention to innovation and entrepreneurship among college students affects college students' entrepreneurial awareness and entrepreneurial practice; the degree of initiative of college students' innovation and entrepreneurship competition affects college students' entrepreneurial effect; and the degree of initiative of college students' innovation and entrepreneurship competition affects college students' entrepreneurial practice.

Relations of Self-assertiveness, Self-esteem, Depression and Abnormal Eating Attitudes among Female University Students with Weight Control Experience (체중조절 경험이 있는 여대생의 자기표현성, 자아존중감, 우울과 이상섭식태도 간의 관련성)

  • Jeon, Hae Ok
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.15 no.4
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    • pp.2207-2216
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    • 2014
  • The purposes of this study were to investigate self-assertiveness, self-esteem, depression and abnormal eating attitudes among female university students with weight control experience and to identify the factors that influence abnormal eating attitudes. Data were collected through self reported structured questionnaire form 170 Korean female university students by convenient sampling methods form May 1 to June 30, 2013. A multiple linear regression showed that depression(${\beta}$=0.20, p=.029) was identified as significant predictors of self control of eating and bulimic symptom. Self-esteem(${\beta}$=-0.22 p=.019) and depression(${\beta}$=0.18, p=.043) were identified as significant predictors of food preoccupation. Self-esteem(${\beta}$=-0.35, p<.001) was identified as significant predictors of preoccupation with being thinner. Self-assertiveness(${\beta}$=0.22, p=.008) and depression(${\beta}$=0.20, p=.034) were identified as significant predictors of preoccupation for dieting. Therefore, for implement the healthy weight control and reducing abnormal eating attitudes, as a strategy for improving self-esteem and self-expressiveness and controlling depression, psychological and mental nursing intervention will be needed.

The Structural and Functional Analysis of Landscape Changes in Daegu Metropolitan Sphere using Landscape Indices & Ecosystem Service Value (경관지수와 생태계용역가치를 활용한 대구광역도시권 경관의 구조적·기능적 변화 분석)

  • Choi, Won-Young;Jung, Sung-Gwan;Oh, Jeong-Hak;You, Ju-Han
    • Journal of the Korean Association of Geographic Information Studies
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    • v.8 no.4
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    • pp.102-113
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    • 2005
  • Ecosystem is composed of human, biotic and abiotic environment. Landscape is an ecosystem which appear in a unit region. These landscape are the spatiotemporal land mosaic which is combined with various landscape elements. And, land use and land cover changes are important factors of landscape structure changes. This study is mainly focused on the analysing the spatiotemporal change patterns of Daegu metropolitan sphere forest landscape, using landscape indices and Ecosystem Service Value (ESV) which quantify ecosystem structures and functions. The results of this study are as follow: The encroachment and fragmentation of forest were due to linear developments, i. e. road construction, rather than large-scale developments such as residental lands or industrial complexes. And, the core area percentages of landscape gradually decreased and these could possibly deteriorate the soundness of forest areas by reducing the core areas which are habitats of species. In addition, there was intimate relations between ESV and forest landscape area. The results of this study can be detached standards for impartial judgements between the logic of development & conservation, and basic standards for the establishment of development plans, i. e. metropolitan-plans, which are adequately reflected ecosystem value.

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