• Title/Summary/Keyword: T-test analysis

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TRANSONIC AEROELASTIC ANALYSIS OF LEARJET AIRCRAFT WING MODEL (리어제트 항공기 날개의 천음속 공탄성해석)

  • Tran, T.T.;Kim, D.H.;Kim, Y.H.
    • 한국전산유체공학회:학술대회논문집
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    • 2011.05a
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    • pp.453-457
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    • 2011
  • In this study, transonic aeroelastic response analyses haw been conducted for the business jet aircraft configuration considering shockwave and flow separation effects. The developed fluid-structure coupled analysis system is applied for aeroelastic computations combining computational structural dynamics(CSD), finite element method(FEM) and computational fluid dynamics(CFD) in the time domain. It can give very accurate and useful engineering data on the structural dynamic design of advanced flight vehicles. For the nonlinear unsteady aerodynamics in high transonic flow region, Navier-Stokes equations using the structured grid system have been applied to wing-body configurations. In transonic flight region, the characteristics of static and dynamic aeroelastic responses have been investigated for a typical wing-body configuration model. Also, it is typically shown that the current computation approach can yield realistic and practical results for aircraft design and test engineers.

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Establishment for Failure Criterion of Adhesively Bonded Joint (접착이음의 파괴 기준 설정을 위한 연구)

  • 이강용;공병석
    • Transactions of the Korean Society of Automotive Engineers
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    • v.8 no.1
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    • pp.183-190
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    • 2000
  • The objective of this work is to develop a criterion for predicting the failure strength of the joints bonded by ductile adhesives. To obtain a criterion, first, fracture tests were carried out for T-peel joint and Single-lap joint with widely differing joints geometries. Then using the fracture loads obtained at tests, the finite element analysis were performed, in which the stresses in the adhesive bonds were calculated in great detail. After examining four epoxy adhesives, it is concluded that the fracture of adhesively bonded joint occurs when the maximum of the ratio of the mean to effective stresses exceeds a constant value which can be determined from analysis and test for each adhesive.

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Textbook Analysis on Practical Arts for Elementary School -focused on 6th curriculum- (초등 실과 교과서 분석 연구 -6차 교육과정 중심-)

  • 최정혜
    • Journal of Korean Home Economics Education Association
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    • v.9 no.2
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    • pp.17-30
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    • 1997
  • Purpose of this study is to analyze the validity of textbook content on practical arts for the 6th curriculum, to grasp the content problems and to propose the strategy of reformation to be satisfied with consumer better than supplier. The data collected from 196 elemantary school teachers who lived in Gyungsang-namdo and analized by SPSS/PC(sup)+ package program. The statistical methods used for analysis were frequency, descriptives, validity, t-test, oneway ANOVA. The major findings can be summarised as follows: 1. The textbooks on practical arts for 3rd, 4th, 5th and 6th grades showed unbalanced division for picture, figure, table unite and evaluation type of all units doesn’t show diversity. 2. The validity of textbook contents on practical arts was found to be the highest for 3rd grade textbook and the lowest for 6th grade one. Among the validity of the evaluation items,‘differentiation with other subject’and ‘usefulness of living’showed high scores, wheres ‘fitness of child level’marked lowest score. 3. There was no significant difference Among the validity contents of teachers based on socio-demographic variables.

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Application of Failure Criteria in Aluminum sheet Forming Analysis (알루미늄합금판재 성형한계 예측을 위한 파단모델 적용)

  • Lee, Eun-Guk;Kim, Heon-Yeong;Kim, Hyeong-Jong;Kim, Heung-Gyu
    • Proceedings of the Korean Institute of Surface Engineering Conference
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    • 2011.05a
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    • pp.207-207
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    • 2011
  • The numerical simulation of the Forming Limit Diagram(FLD) test was carried out to calculate the limiting dome height(LDH: ISO12004-2) for aluminum alloy sheet Al6061-T6. The finite element analysis was used as an effective method for evaluating formability and diagnosing possible production problems in sheet stamping operations. To predict fracture during the stamping process, several failure models such as Cockcroft-Latham, Rice-Tracey, Brozzo and ESI-Wilkins-Kamoulakos(EWK) criteria were applied. The predicted results were discussed and compared with the experiments for Al6061-T6.

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Static strength of collar-plate reinforced tubular T-joints under axial loading

  • Shao, Yong-Bo
    • Steel and Composite Structures
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    • v.21 no.2
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    • pp.323-342
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    • 2016
  • To study the effect of collar-plate reinforcement on the static strength of tubular T-joints under axial loading, fundamental research work is carried out from both experimental test and finite element (FE) simulation. Through experimental tests on 7 collar-plate reinforced and 7 corresponding un-reinforced tubular T-joints under axial loading, the reinforcing efficiency is investigated. Thereafter, the static strengths of the above 14 models are analyzed by using FE method, and it is found that the numerical results agree reasonably well with the experimental data to prove the accuracy of the presented FE model. Additionally, a parametric study is conducted to analyze the effect of some geometrical parameters, i.e., the brace-to-chord diameter ratio ${\beta}$, the chord diameter-to-chord wall thickness ratio $2{\gamma}$, collar-plate thickness to chord wall thickness ratio ${\tau}_c$, and collar-plate length to brace diameter ratio $l_c/d_1$, on the static strength of a tubular T-joint. The parametric study shows that the static strength can be greatly improved by increasing the collar-plate thickness to chord wall thickness ratio ${\tau}_c$ and the collar-plate length to brace diameter ratio $l_c/d_1$. Based on the numerical results, parametric equations are obtained from curving fitting technique to estimate the static strength of a tubular T-joint with collar-plate reinforcement under axial loading, and the accuracy of these equations is also evaluated from error analysis.

A Study on the Relationship of Marital Intimacy, Depression, and Menopausal Symptoms in Middle-aged Women (중년여성의 부부친밀감, 우울과 갱년기 증상의 관계)

  • Kim, Su Jin;Kim, Se Young
    • Women's Health Nursing
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    • v.19 no.3
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    • pp.176-187
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    • 2013
  • Purpose: This study aims to identify the relationship between marital intimacy, depression, and menopausal symptoms, and to provide basic data for the health promotion of middle-aged women. Methods: A sample of 231 middle-aged women was recruited from four cities in Korea. The survey was conducted with participants using self-reported questionnaire from July 9 to November 11, 2011. The data were analyzed using descriptive statistics, t-test, ANOVA, and Correlation Analysis. Results: There were differences of marital intimacy scores that were statistically significant in educational background (F=6.88, p=.001), religion (t=3.96, p<.001), own job (F=4.47, p=.012), own salary (F=3.01, p=.019), spouse's salary (F=6.72, p<.001), ownership of residence (t=4.00, p<.001), leisure with spouse (t=-5.05, p<.001), current treatment of disease (t=2.22, p=.027), and current disease (t=2.53, p=.012). Marital intimacy was correlated with depression (r=-0.61, p<.01) and menopausal symptoms (r=-0.39, p<.01). Conclusion: Marital intimacy in middle-aged women is closely related to both depression and menopausal symptoms. The nursing program that improves marital intimacy will be useful to promote the health of middle-aged women.

Multiple intelligences and critical thinking disposition in nursing students (간호학생의 다중지능과 비판적 사고 성향)

  • Hwang, Eunhee;Shin, Su Jin
    • Journal of Korean Academy of Fundamentals of Nursing
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    • v.21 no.4
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    • pp.433-445
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    • 2014
  • Purpose: This study was conducted to examine relationships between critical thinking disposition and multiple intelligences. Method: Participants were nursing students (N=186) who completed a questionnaire assessing critical thinking disposition and multiple intelligences. Data were analyzed using descriptive statistics, t-test, analysis of variance with post hoc comparison, and Pearson correlation coefficients. Results: For type of multiple intelligences, 32.9% of students had the strongest fit for "interpersonal intelligence" type and 20.1% for "intrapersonal intelligence" type. Mean score for critical thinking disposition was $3.42{\pm}0.37$. Factors related to critical thinking disposition were participation in club activities (F=5.962, p=.001) with a representative role in the club (t=2.140, p=.034). There were significant differences in interpersonal intelligence scores by personality traits (t=2.445, p=.015), participation in club activities (F=10.003, p<.001), and friendship (t=2.539, p=.012); and significant differences in intrapersonal intelligence scores by participation in club activities (F=3.862, p=.010), having a representative role in the club (t=2.101, p=.037), and friendship (t=2.220, p=.029). Conclusion: Results indicate that critical thinking disposition is significantly associated with multiple intelligences and suggest that multiple intelligences should be considered to enhance critical thinking disposition when tailored teaching is adopted in nursing education.

Health Perception and Family Support as Influencing Factors on Depression in Hospitalized Elderly Patients (건강지각과 가족지지가 입원 노인환자의 우울에 미치는 영향)

  • Lee, Sun-Ok;Kim, Moon-Jeong
    • The Korean Journal of Health Service Management
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    • v.9 no.4
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    • pp.145-155
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    • 2015
  • Objectives : The purpose of this study was to test the influencing effects of health perception and family support on depression in elderly patients. Methods : Two-hundred forty-nine hospitalized geriatric patients were recruited in B city, South Korea. They were asked to complete a questionnaire, and 214 data sets were included in multiple regression analysis. Results : Subjects perceived a higher level of depression. Influencing factors of depression were hospitalization experience (t=3.476, p=.001), health perception (t=-3.310, p=.001), education (t=2.684, p=.008), economic satisfaction (t=2.579, p=.011), satisfaction with allowance (t=2.262, p=.025), and family support (t=-2.200, p=.029). The model was statistically significant explaining 36.3% of the variance (F=21.257, p<.001). Conclusions : In dealing with depression, nurses in elderly care facilities should be more concerned about patients with hospitalization experiences. Interventions to improve health perception should be provided to elderly patients, and educational programs on how to support patients are needed for the families of patients.

The Impacts of Guideline for Digestives on Physicians' Prescription of GI medication (소화기관용약제 처방지침이 의사의 소화기관용약 처방률에 미치는 효과분석)

  • Kim, Dong-Sook;Park, Choon-Seon;Jang, Sun-Mee
    • Korean Journal of Clinical Pharmacy
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    • v.18 no.2
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    • pp.124-131
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    • 2008
  • The impacts of guideline for digestives on physicians' prescription of GI medication Clinical practice guidelines provide benefits to physicians, patients, and researchers. It also helps doctors to make decisions in medical services. In many countries, practice guidelines lead to activities of quality improvement and are developed using evidence based methods. This research was to assess the impacts of Korean Medical Association's guideline for digestives on the change of physicians' behavior. This study was progressed as one-group pre-test post-test quasi-experimental design using health insurance claims data. The unit of analysis was institution. Data was analyzed using paired t-test for change of prescription rate before and after the distribution of practice guidelines. And the multiple regression analysis was performed to examine the independent impact of the guideline on the prescribing rate of GI medication. Prescription rates of GI medication per claim by medical institution increased significantly, 1.98%point (from 50.27% to 52.25%) and multivariate regression analysis showed significant increase in the prescription rate of GI medication after the distribution of guideline (p<0.001). In conclusion, the distribution of guideline for digestive might not have the effects on the change in provider's behavior. Furthermore, to activate the use of practice guideline, it would be necessary to educate the contents to physicians as well as to develop practice guideline.

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Self-efficacy and Body Satisfaction according to College Students' Appearance Management Attitudes Typology (대학생의 외모관리태도 유형에 따른 자기효능감과 신체만족)

  • Park, Eun-Hee;Cho, Hyun-Ju
    • The Research Journal of the Costume Culture
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    • v.20 no.4
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    • pp.515-528
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    • 2012
  • The purpose of this study was to classify appearance management attitudes into groups and analyze the difference of self-efficacy and body satisfaction by the groups. Questionnaires were administered to 255 college students living in Deagu Metropolitan City and Kyungbook province. The data collected were analyzed by using frequency, factor analysis, cluster analysis, correlation analysis, ANOVA, Duncan-test, t-test, and ${\chi}^2$-test. The findings were as follows. Appearance management attitudes of college students were classified into three groups such as group health body, low body interest group, emphasizes collective body. The appearance management attitudes showed significant correlation with the sub-variables of self-efficacy and body satisfaction. Male students showed no significant difference in self-efficacy by the groups while female students showed a significant one in task performance which was a sub-variable of self-efficacy. Both of the male and female students showed a significance of difference in the gap between actual and ideal weight which was a sub-variable of body satisfaction by the groups. Gender of college students showed distinction between the sub-variables of self-efficacy factors such as task performance, and anxiety and body satisfaction such as BMI, the difference between current height and ideal height, the difference between current weight and ideal weight.