• Title/Summary/Keyword: Correlation factor

Search Result 6,408, Processing Time 0.038 seconds

Numerical investigations on the effect of tortuosity on friction factor in superconducting CICC configuration

  • Vaghela, Hitensinh;Lakhera, Vikas;Bhatt, Kunal;Sarkar, Biswanath
    • Progress in Superconductivity and Cryogenics
    • /
    • v.23 no.4
    • /
    • pp.49-55
    • /
    • 2021
  • The Cable in Conduit Conductor (CICC) configurations are designed, tested and realized to make high field superconducting (SC) magnets. The evolution of CICC design makes it challenging to forecast thermo-hydraulic behavior. A common objective of thermo-hydraulic studies is to obtain the most reliable predictive correlation for friction factor in CICC geometries and to reduce the dependency on the experiment. So far, only the void fraction and Reynolds number have been considered in the predictive correlations in an explicit way. In the present paper, the CICC twisting pattern dependency, called tortuosity (τ), on the pressure drop prediction, has been assessed through a numerical simulation approach. The CICC twisting pattern with 6+1 petals (solid conductor in the present study) with different twisting pitches is mimicked in the numerical simulation for the range 100 ≤ Re ≤10000 and 1 < τ < 1.08 and a correlation for friction factor, f, has been proposed as a function of Re and τ.

Study on fracture mechanics of granite specimens with different precast notch depths based on DIC method

  • Shuwen Cao;Hao Shu
    • Geomechanics and Engineering
    • /
    • v.33 no.4
    • /
    • pp.393-400
    • /
    • 2023
  • Displacements near crack and stress intensity factor (SIF) are key parameters to solve rock failure issue when using fracture mechanics. In order to study the horizontal displacement and stress intensity factor of the mode I fracture, a series of three-point bending tests of granite specimens with central notch were carried out. The evolution of horizontal displacements of precast notch and crack tip opening displacements (CTOD) were analyzed based on the digital image correlation (DIC) method. Stress intensity factors for three-point bending beams with arbitrary span-to-width ratios(S/W) were calculated by using the WU-Carlsson analytical weight function for edge-crack finite width plate and the analytical solution of un-cracked stress by Filon. The present study provides a high efficient and accurate method for fracture mechanics analysis of the three-point bending granite beams.

A study on the relationship of family support and personality with quality of life in the Patients receiving radiotherapy for cervix cancer (방사선 치료를 받는 자궁경부암 환자의 가족지지와 성격이 삶의 질에 미치는 영향)

  • Noh, Young-Hee
    • The Journal of Korean Society for Radiation Therapy
    • /
    • v.8 no.1
    • /
    • pp.149-159
    • /
    • 1996
  • This descriptive correlational study was undertaken in order to investigate the relationship of family support and personality with quality of life in patients receiving radiotherapy for cervix cancer and to provide basic data to help them improve a better quality of life. The subjects for this study Were 80 out-patients undergoing a radiation therapy at C university hospital in K-city, from April, 1992 to October, 1994. The data were obtained using a convenience sampling technique. The tools used for this study were Ro's quality of life scale, Kang's family support scale and Wallston & others health locus of control scale. The collected data were analyzed by the SAS program using percentage, mean, standard deviation, pearson's correlation coefficients. The result were as follows : 1. The total average score of the quality of life of the subjects was 138.95(minimum score 121-maximum score 164), item mean score(range 1-5) was 2.95. The total average score of the family support of the subjects was 32.55 (minimum score 16-maximum score 47), item mean score(range 1-5) was 2.95 The total average score of the health locus of control of the subjects was 37.00 (minimum score 24-maximum score 49), item mean score (range 1-6) was 3.36. 2 The results of the analysis of the relationship between the quality of life scale and the health locus of control were as follows : the total average score in the quality of life of internal locus of control scale was 136.97, the total average score in the quality of life of external locus of control scale was 144.90. 3. There was a significant positive correlation between the health locus of control and the quality of life(r = 0.2927, p<0.01). The result of the analysis of the relationship between the each factor in the quality of life and health locus of control were as follows : There were significant differences between the health locus of control and emotional state factor(r=0.1514, p<0.01), economic life factor(r=0.2560, p<0.05), self-esteem factor(r=0.2289, p<0.05), physical state and function factor(r=0.1455, p<0.05), relationship with neighbors factor(r=0.0754, p<0.05), relationship with family factor (r=0.3324, p<0.01). 4. There was a significant positive correlation between the family support and the quality of life(r=0.459, p<0.001). The result of the analysis of the relationship between the each factor in the quality of life and family support were as follows : there were significant differences between family support and emotional state factor (r=0.3891, p<0.01), self-esteem factor(r=0.2661, p<0.05), relationship with family factor (r=0.4353, p<0.001).

  • PDF

A Study on Perceived Family Support and Anxiety in Hemiplegic Patients (편마비 환자가 지각한 가족지지와 불안과의 관계 연구)

  • 이명해;강현숙
    • Journal of Korean Academy of Nursing
    • /
    • v.21 no.1
    • /
    • pp.50-62
    • /
    • 1991
  • The purposes of this study were to identify causal factors of Anxiety and to analyze correlation between perceived family support and anxiety in hemiplegic patients. The subjects of this study were 88 hospitalized hemiplegic patients at Kyung - Hee Oriental medicine Hospital. Data were collected by using interview with questionaire from Jan. 15 to Mar, 31, 1990. The measurement tools used by this researcher were Kang's family support scale, Spielberger's trait anxiety scale and the other anxiety scale which was developed by this researcher, approved it's reliability and validity. For the purposes of the study, the collected data were analyzed by frequency, t-test, ANOVA and the hypothesis was tested by pearson correlation, partial correlation. The results of the study were as follow. 1) The analysis of causal factor of anxiety higher anxiety these three cases ; \circled1 1st causal factor was the delayed recovery of paralyzed upper limbs(2.42$\pm$1.27). \circled2 End causal factor was the dysfunction of physical ability(2.30$\pm$1.29). \circled3 3rd causal factor was difficulty for walking(2.30$\pm$0.83) and the anxiety level(2.02$\pm$0.83) of physical factor was the highest level than any other factors. 2) The hypothesis that the more perceived family support level is the less anxiety level of patient was supported(r=-.29, p=.003). 3) The analysis of the general characteristics exerting influences on anxiety level patients ; (sex, age, marrital status, religious, education level, occupation, economic status, experience of hospitalization, care giver, the period of hospitalizatiot side of paralysis). In this analysis, any factor has not a statistical significance.(p>.05). 4) The analysis of the relationship about effective factors of family support level by the general characteristics of patient (sex, age, marrital status, religious, education level, occupation, economic status, experience of hospitalization, care giver, the period of hospitalization, side of paralysis). In this analysis, there was significant difference on perceived family support between married and bereaved patients(t=-2.68, p= .009) As a result of this study, anxiety level of physical factor was higher than any other factors (psychological factor, social factor) and the delayed recovery of paralyzed upper limbs is the largest causal factor of anxiety of physical factor. Meanwhile, the relationship between the degree of family support and the level of anxiety was negatively correlated but the degree of relationship was low. Therefore, one can infer from this study that sufficient information about recovery of physical problems and family support were effective in preventing and reducing anxiety in hemiplegic patient.

  • PDF

Relations of School Organizational Climate and Teachers' Job Stresses (학교조직풍토와 교사의 직무스트레스의 관계)

  • LEE, Kyeong-Hwa;JUNG, Hye-Young
    • Journal of Fisheries and Marine Sciences Education
    • /
    • v.21 no.1
    • /
    • pp.121-133
    • /
    • 2009
  • This study tested the relations of schools organizational climate and teachers' job stresses, perceived by 913 teachers from 45 elementary, junior- and senior-high schools. Pearson's correlation analysis for the relations between the sub-factors of both organizational climate and job stresses and cannonical correlation analysis for the relative contribution of individual variable of organizational climate upon job stress were applied for the test. The results of Pearson's correlation analysis showed that while 'intimacy', 'esprit', 'considerations', and 'production emphasis' climate had negative correlations with job stress sub-factors, 'disengagement' and 'aloofness' climate had positive correlation. 'Student guidance', a sub-factor of job stresses, did not have statistically significant correlation with any sub-factors of organizational climate. Findings from cannonical correlation analysis showed 2 significant cannonical functions to explain the relations between the sets of variables. 'Disengagement' from organizational climate positively contributed with 'authority forfeiture' and 'dissention and conflict' of the job stresses variables.

The Reliability and Validity Test of Psychosocial Well-being Index(PWI) (사회심리적 건강 측정 도구의 신뢰도 및 타당도 검정)

  • 김정희
    • Journal of Korean Academy of Nursing
    • /
    • v.29 no.2
    • /
    • pp.304-313
    • /
    • 1999
  • The purpose of this study is to test the reliability and validity test of PWI to utility of PWI. this newly developed by Sejin Jang which measures stress. The subject were 186 workers in service area. Cronbach's a and Guttman split-half coefficient is used to test the reliability of PWI. Factor analysis and the correlation of the GHQ-60. GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI is used to convergent validity and discriminant validity. The important results of this study are as follows : Cronbach's $\alpha$ coefficient of data was 0.894 and Guttman split-half coefficient was 0.7097. The PWI was classified as 13 principle component (eigenvalue>1.0). After exploring 4 factor structure according to previous study result, 4 factors was explained 40.5% out of the total variance. The factor 1 was explained 15.9% and then the rest three factor was 24.6%. Factor 2 and 4 showed good agreement but factor 1 and 3 did not. Depression-related items were classified two factors. Anxiety and depression-related items were loaded unifactor. It was not clear that the PWI was consist of 4 concepts(factors). The correlation of the GHQ-60, GHQ-30, GHQ-28, GHQ-20, and GHQ-12 with the PWI were 0.744~0.905. According to findings of this study. the PWI showed a high degree of validity and reliability. Thus it is recommended to use the PWI in general setting for screening for stress. In addition, it is necessary to clarify the concept of depression and anxiety. In the further study. it my be considered to the factor structure of PWI and studied to two or unidimensional factor structure.

  • PDF

Intolerance of Uncertainty Scale: Construct validity of Prospective and Inhibitory factor structure (불확실성에 대한 인내력 부족 척도: 전향적·억제적 요인의 구인 타당도 검증)

  • Choi, Hyo Sun;Kim, Eun-Kyung
    • Journal of the Korea Academia-Industrial cooperation Society
    • /
    • v.21 no.9
    • /
    • pp.338-344
    • /
    • 2020
  • Intolerance of Uncertainty is associated with numerous psychopathologies, including generalized anxiety disorders. However, several studies differ in the factor structures applicable for the Intolerance of Uncertainty Scale (IUS), and there exists a debate regarding the factorial and construct validity. Thus, in the current study, the IUS was newly translated to explore and verify the structures and factors relative to the cultural background of Korea. The study involved an exploratory factor analysis of randomly extracted data from 260 of 533 adults selected. Results determined that a prospective factor of 3 items and inhibitory factor of 5 items was appropriate. In addition, a confirmatory factor analysis and correlation analysis of the remaining 273 data revealed that a structural model comprising of the 8-items two factors model was well suited (x2=37.699, TLI=0.951, CFI=0.969, RMSEA=0.063, SRMR=0.039), and showed significant static correlation with worry, depression, and state-trait anxiety.

Pressure Drop in Microtubes and Correlation Development (마이크로관 내 압력강하 특성 및 상관식에 관한 연구)

  • Hwang, Yun-Wook;Kim, Ju-Hyok;Kim, Min-Soo
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
    • /
    • v.18 no.1
    • /
    • pp.38-46
    • /
    • 2006
  • The characteristics about the pressure drop in microtubes have been investigated. The test tubes are the circular, seamless, stainless steel tubes with an inner diameter of 0.244, 0.430, and 0.792 mm, respectively. R-l34a was used as a test fluid. Early flow transition which has been reported in some previous studies is not found in single-phase flow pressure drop tests. The conventional theory between friction factor and Reynolds number predicted the experimental friction factors within an absolute average deviation of $8.9\%$. The two-phase flow pressure drop increases for higher quality and mass flux, and for reduced inner diameter. The existing correlations fail to predict the experimental data. A new correlation to predict the two-phase flow pressure drop is developed in the form of the Lockhart-Martinelli correlation. The effects of the tube diameter and the surface tension were considered, and the correlation predicted the experimental data within an average absolute deviation of $8.1\%$.

A Semi-Empirical Correlation for an Adiabatic Interfacial Friction Factor (단열 계면 마찰계수에 대한 준 실험식)

  • Nam, Ho-Yun;Chun, Moon-Hyun
    • Nuclear Engineering and Technology
    • /
    • v.26 no.1
    • /
    • pp.108-118
    • /
    • 1994
  • A semi-empirical correlation has been developed for adiabatic interfacial friction factors in a long horizontal air-water countercurrent stratified flow conditions. Using a pipe and duct test sections, a series of experiments hate been conducted varying non-dimensional water depth and flow rates of air. On the basis of simultaneous measurement of the main flow parameters in a horizontal pipe and a duct, a semi-empirical correlation for the interfacial friction factor in a stratified flow regime has been developed employing a new concept of surface roughness in wavy flow. A total of 201 data point, including 15 concurrent pipe flow test data of others, have been used in the present analysis. A comparison between the data and the predictions of the present correlation shows that the agreement is within $\pm$30%.

  • PDF

Development of a Questionnaire to Measure Resilience in Children with Chronic Diseases (만성질환아의 극복력(Resilience) 측정도구 개발)

  • Kim, Dong-Hee;Yoo, Il-Young
    • Journal of Korean Academy of Nursing
    • /
    • v.40 no.2
    • /
    • pp.236-246
    • /
    • 2010
  • Purpose: The purpose of this study was to develop and evaluate a Korean questionnaire to measure resilience in children with chronic illness. Methods: Item construction was drawn from an extensive review of the literature, existing questionnaires and interviews with parents. Content validity was tested by experts. To further refine the questionnaire and test its reliability and validity, data were collected from the 202 children with asthma, diabetes mellitus or nephrotic syndrome. Corrected items were used to total correlation coefficient and test-retest reliability. Questionnaire testing was conducted using factor analysis, Cronbach's $\alpha$, and correlation coefficients. Validity of the questionnaire was tested using internal consistency, construct validity, and criterion-related validity. Results: Components of the questionnaire were in three domains; interpersonal characteristics, characteristics of coping, and intrapersonal characteristics. Factor analysis is showed five factors; positive self-understanding, self-reliance, resourcefulness, perception of positive family relationships, and intimacy. The questionnaire showed a high internal consistency. A significant positive correlation with the Numerical Rating Score and negative correlation with the Child Depression Inventory support the validity of the questionnaire. Conclusion: This instrument demonstrated high reliability and validity. Therefore, this instrument can contribute to the evaluation of resilience of chronically ill children and to any subsequent intervention as well as to develop a theory for resilience.