• Title/Summary/Keyword: ANOVA (Analysis of Variance)

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Study on Surface Roughness Characteristics of Cutting Thread Sensors (절사센서의 표면거칠기 특성에 관한 연구)

  • Son, Jae-Hwan;Lee, Ho-Young;Park, Chul-Woo;Roh, Joon-Ho;Han, Chang-Woo;Oh, Chang-Hwan;Seo, Min-Kyo
    • Journal of the Korean Society of Industry Convergence
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    • v.10 no.4
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    • pp.195-200
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    • 2007
  • These days, various and complex threads are developed, so it is necessary to develop the cutting a thread sensors for checking a cut thread in severe environment and it is very important to evaluate the quality of the cutting a thread sensors. The analysis of variance(ANOVA) method is very useful method on the quality evaluation field. In this study, the quality is evaluated by one way layout ANOVA method with the surface roughness data. The experiment is carried out by 3 sensors and the result show that the sensors have the good quality in precision.

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Analyzing Effective Factors on Hydrogen Release Based on Response Surface Method and Analysis of Variance (반응표면법과 ANOVA 기반의 수소 누출에 대한 유효인자 분석)

  • JUNSEO LEE;SEHYEON OH;SEUNGHYO AN;EUNHEE KIM;BYUNGCHOL MA
    • Journal of Hydrogen and New Energy
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    • v.34 no.6
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    • pp.712-721
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    • 2023
  • While hydrogen is widely used, it has a low minimum ignition energy, raising safety concerns when using it. This research studied which parameters are the key variables in the hydrogen release and diffusion. These parameters were divided into six process variables in the initial release and two environmental variables in the dispersion. One hundred and twenty cases were selected through design of experiment, and the end-point in each case were analyzed using PHAST. Afterwards, an end-point prediction model was developed using RSM and ANOVA, and the impact of each variable on the endpoint was analyzed. As a result, the influence of eight variables was graded. The nozzle diameter had the greatest influence on the end-point, while the pipe roughness coefficient had no effect on the end-point. It is expected that these results will be used as basic data to improve safety across all fields of hydrogen handling facilities.

Knowledge Discovery in Aerodynamic Design Space using Data Mining (데이터 마이닝을 통한 공력설계공간 지식습득)

  • Jeong, Sin-Gyu;;, 동북대학교
    • Journal of the Korean Society for Aeronautical & Space Sciences
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    • v.34 no.1
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    • pp.49-55
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    • 2006
  • Two data mining techniques, analysis of variance (ANOVA) and self-organizing map (SOM), are applied to knowledge discovery in aerodynamic design space. These methods make it possible to identify the effect of each design variable on the objective functions. Furthermore, ANOVA shows the effect of interaction between design variables on the objective function and SOM visualizes the trade-off among objective functions. Present methods are applied to the result of the supersonic wing design which includes 72 design variables and 4 objective functions.

Natural isotopes and trace element analyses in glass samples (판유리 시료에서 동위원소 및 미량원소 분석법)

  • Min, Ji-Sook;Heo, Sangcheol;Kim, Jae-Guin;Kim, Eun-Ho;Kim, Dong-Wook;Chung, Hee-Sun
    • Analytical Science and Technology
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    • v.20 no.3
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    • pp.219-226
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    • 2007
  • Glass is frequently encountered as types of materials that are submitted to forensic science laboratories as a result of trace evidence transfers. The repeatability and the reproducibility of trace element analysis were presented. An analysis of variance (ANOVA) was performed on laser ablation inductively coupled plasma spectrometric analyses of the fragments to identify the source. Pairwise comparisons were completed for all samples. In a pairwise comparison, each sample was compared to each other for a possible [n(n-1)/2] (n : numbers of the samples) total comparison to associate/discriminate samples using Tukey's HSD method. The aim of this study was to determine the utility of LA-ICP-MS for multi-element analysis of forensic samples. The 12 glass fragments from two manufacturers were collected and analyzed to identify the source. An analysis of variance (ANOVA) was performed on 31 elements in NIST 612 Trace elements in Glass. Elements were classified into four categories defined by the combination of precision and variation of inter-samples. We selected 11 elements, 209Bi, 90Zr, 121Sb, 178Hf, 59Co, 238U, 208Pb, 140Ce, 118Sn, 49Ti and 137Ba. 6 pairs out of 66 possible pairs were not distinguished when compared by 137Ba (p<0.05). However, all samples were distinguished using both 49Ti and 137Ba (p<0.05). In conclusion, multi-elemental analysis with LA-ICP-MS is a potential tecnique for the discrimination of forensic samples.

A study on the determinants of job stress responses of the staff nurses (일반 간호사의 직무 스트레스 반응에 대한 결정 요인)

  • Kim, Jeong-Hee;Park, Sung-Ae
    • Journal of Korean Academy of Nursing Administration
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    • v.9 no.2
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    • pp.217-232
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    • 2003
  • Purpose : This paper was attempted to identify the job stress related factors among the staff nurses and to provide the basic data concerning development of stress management program focused on hospitals. Method : The subjects were 309 staff nurses at two general hospitals in Seoul. Data were collected with self-reported questionnaires and analyzed by SPSS-PC+10.0 for descriptive analysis, ANOVA, stepwise multiple regression, factor analysis. Results : The subjects exhibit significantly highest level of 'the participation in decision making factor'. The mean score of 'control coping strategies' was higher than 'avoid coping strategies'. The mean scores of social support and stress responses were high. The main factor that affected the stress responses was 'the job characteristic factor' and it was explained 23.0% out of the total variance of the stress responses. Also, it would be explained 42.6% out of the total variance of the stress responses with 'the control coping strategies, work overload factors, social support, and participation in decision making factors'. Conclusion: For developing the hospital- focused stress management program for staff nurses, 'the participation in decision making factors' and 'the job characteristics' should be considered. Also, the organizational efforts and supports should be required to support and use of 'control coping strategies' of nurses

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Effects of Meridian Acupressure on Constipation in the Institutionalized Elderly (경혈지압이 시설노인의 변비완화에 미치는 효과)

  • Kim, Mi Young;Kang, Eun Hee;Byun, Eun Kyung
    • The Korean Journal of Rehabilitation Nursing
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    • v.17 no.1
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    • pp.48-55
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    • 2014
  • Purpose: In this study, we attempted to provide an evidence for the effects of meridian acupressure on relieving and preventing constipation in the institutionalized elderly. Methods: The research design was a non-equivalent control group, non-synchronized design. The subjects consisted of 31 institutionalized elderly (experimental group: 16, control group: 15). The experimental group was given meridian acupressure for 10 minutes daily for 2 weeks. The data was analyzed by the ${\chi}^2$-test, Fisher's exact test, t-test and repeated measures ANOVA. Results: The number of bowel movements per week of the experimental and control group performed meridian acupressure verified by repeated-measures analysis of variance revealed that interaction existed between the meridian acupressure availability and the measurement point (F=98.183, p<.001). Repeated measures analysis of variance to compare the changes in Bristol stool form scale scores of the experimental and control group performed meridian acupressure revealed that interaction existed between the meridian acupressure availability and the measurement point (F=48.896, p<.001). Conclusion: The results of this study show the meridian acupressure is a useful nursing intervention on constipation in the institutionalized elderly.

A Study on Health Behaviors and the Risk Factors of Blood Pressure of Adult Women in a Rural Area (일 농촌지역 성인여성의 건강관련행위와 혈압 위험요인에 관한 연구)

  • 전성숙;황진희
    • Korean Journal of Health Education and Promotion
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    • v.21 no.3
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    • pp.117-131
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    • 2004
  • Purpose: This study was conducted to evaluate the health behaviors and to find out risk factors of blood pressure of adult women in a rural area. Method: The convenient sample consisted of 159 adult women who lived in G-gun. The data was collected using a self-report questionnaire for health behaviors and mercury type sphygmomanometer for BP, between Jun I and August 15, 2003. Health behaviors measured smoking, alcohol, salt, lipid, stress, exercise, coffee, BMI and medication. To accomplish the goal of study, descriptive statistics, t-test, $x^2$-test, ANOVA and multiple regression analysis were. performed with SPSS 10.0. Results: The average age of subjects was 49.2(SD7.34)years old. The average SBP and DBP of subjects were 126.22mmHg(SDl6.73) and 8 1.25mmHg(SDl 0.31). There were significant differences in smoking(p=.000), cigarette consumption(p=.001), smoking duration(p=.000), BMI(p=.033), medication (p=.001), family history(p=.000) between normotensive and hypertensive. The main risk factors on SBP were medication, age, BMI, family history and smoking duration by 35.7% of the total variance these variables explained SBP. The main risk factors on DBP were BMI, education and medication by 17.60% of the total variance these variables explained DBP. Conclusion: These results suggest that health professional have to emphasize prevention of obesity, lasting medication and no smoking for prevention and management of hypertension in community health promotion program.

Analysis of Factors Affecting the Health Behavior of Taxi-drivers (택시운전기사의 건강행위에 영향을 미치는 요인분석)

  • Ko, Ja-Kyung
    • Journal of East-West Nursing Research
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    • v.15 no.2
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    • pp.71-81
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    • 2009
  • Purpose: This study was conducted to find out interrelation of health behavior and related variables to provide basic data for an effective health promotion for the taxi-divers. Methods: 293 male taxi-drivers from 2 cities in Korea participated in this study. The data were collected using questionnaires from April 17th to Jun 3rd, 2006, and analyzed by descriptive statistics, t-test, ANOVA, Pearson correlation, and multiple regression. Results: There were statistically significant differences according to monthly income, past illness or surgery, current disease or medication, frequency of fright on daily driving (FFDD), driving fatigue, working style, social support in health status; current disease or medication, FFDD, driving fatigue, duty shift, social support in health perception; body mass index (BMI), FFDD, driving fatigue, intention of changing job, social support in health behavior. Social support, health status, health perception, and health behavior were significantly correlated with one another. The multiple regression analysis showed that health perception (17.8%), BMI (6.8%), intention of changing job (5.7%), and driving fatigue (4.2%) explained the 34.5% variance of health behavior. And the 22.6% of variance of health perception was explained by social support (12.2%), health status (6.9%), and duty shift (3.2%). Conclusions: To promote the taxi-drivers' health, nursing intervention strategies unique for them should consider health behavior and affecting factors.

Does Bribery Sand the Wheels? New Evidence from Small and Medium Firms in Vietnam

  • NGUYEN, Toan Ngoc
    • The Journal of Asian Finance, Economics and Business
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    • v.7 no.4
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    • pp.309-316
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    • 2020
  • This research aims to revisit the hypothesis that bribery hurts firm performance in the context of a perceptibly corrupt country. Specifically, we use micro-data from Vietnamese small and medium firm surveys in 2013 and 2015 to examine whether bribery impedes firm revenue growth and labor productivity growth. An issue arising in this type of research is the potential endogeneity between firm bribing behaviors and firm performance. To go around the issue, we follow the literature to instrument bribery variable with the average probability of bribery in other provinces. We further employ the Analysis of Variance technique (ANOVA) to unveil if the effect of bribery is dependent on bribing purposes. The regression results show that firm performance is significantly influenced by firm size, firm age and firm bribing behavior. Larger firms are more likely to grow faster while firm performance tends to be negatively related to firm age. Particularly, we find that bribery significantly impedes firm revenue growth and labor productivity growth. The analysis of variance shows that the effect of bribery on firm performance may vary across bribing purposes. Our findings, therefore, support the sand-the-wheels hypothesis that bribery hurts firm performance even in a highly corrupt business environment.

Optimum Design Criteria of 250 kW Premium Efficiency Traction Induction Motor Using RSM & FEM (유한요소법과 반응표면법을 이용한 250 kW급 견인 유도전동기 최적설계)

  • Lee, Jung-Ho;Yun, Tae-Won
    • Journal of the Korean Magnetics Society
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    • v.20 no.6
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    • pp.239-243
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    • 2010
  • This paper deals with the optimum design criteria for the premium efficiency of 250 kW traction induction motor, using response surface methodology (RSM) and finite element method (FEM). The focus of this paper is found firstly a design solution through the comparison of torque according to rotor bar shape, rotor dimensions variations. And secondly a mixed resolution with central composite design (CCD) is introduced and analysis of variance (ANOVA) is conducted to determine the significance of the fitted regression model. The proposed procedure allows to be optimized the rotor copper bar shape, rotor slot, rotor dimensions starting from an existing motor or a preliminary design.