• Title/Summary/Keyword: Variance of Analysis

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Optimization of MOF-235 Synthesis by Analysis of Statistical Design of Experiment (통계학적 실험계획법 해석을 통한 MOF-235 합성 최적화)

  • Chung, Mingee;Yoo, Kye Sang
    • Applied Chemistry for Engineering
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    • v.30 no.5
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    • pp.615-619
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    • 2019
  • Statistical design of experiments was performed to optimize MOF-235 synthesis process. Concentrations of terephthalic acid (TPA), iron (III) chloride hexahydrate, N,N-dimethylformamide (DMF) and ethanol were important factors to develop the crystal structure of MOF-235. MOF-235 was synthesized with various concentrations of the listed chemicals above and the crystallinity was measured by XRD. The effect of the composition on the synthesis of MOF-235 was evaluated using a statistical analysis. For the variance analysis using F-test, the concentration of ethanol showed the greatest effect on the crystallinity and TPA the least influential. A regression model for predicting the crystallinity of MOF-235 was derived and the prediction results for two synthetic variables were presented using contour plots. Finally, the crystallinity was predicted by a mixture method with $FeCl_3$, ethanol and DMF.

School safety education status and the awareness and practice of safety among middle school students: 「First aid, disaster safety, traffic safety, and daily life safety」 (중학생들의 학교안전교육 실태와 안전분야 지식 및 실천 :「재난안전, 응급처치, 교통안전, 생활안전」)

  • Lee, Hyo-Cheol;Jang, Pureumi;Kim, Jung-Hwan
    • The Korean Journal of Emergency Medical Services
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    • v.25 no.2
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    • pp.129-143
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    • 2021
  • Purpose: This study aimed to identify the current status of school safety education and the differences in knowledge and practice of middle school students. Methods: A structured questionnaire was distributed to 418 middle school students in J province. The questionnaires consisted of 35 questions on the status of school safety education as well as the four school safety education domains of first aid, disaster safety, traffic safety, and daily life. Data were analyzed using frequency analysis, cross-tabulation analysis, a t-test, analysis of variance, and Pearson's correlations. Results: Awareness regarding the top seven standards for school safety and interest in school safety education were both relatively low. Among all the different kinds of safety accidents, those related to school violence(33.8%) and life safety(24.9%) were experienced the most in school. A more pleasant school life and better peer relationships led to interest in school safety(p=.000)(p=.000), awareness regarding the top seven standards for school safety(p=.022)(p=.009), adoption of coping measures(p=.000)(p=.000), and practice(p=.000)(p=.000) in case of safety accidents(p=.000)(p=.000). Conclusion: To increase awareness regarding the seven standards for school safety education and raise interest in safety education, it is necessary to cultivate experts and actively utilize them and to prepare systematic and continuous school safety education programs.

The Technology Application of Fourth Industrial Revolution in Organization (조직 내 4차 산업혁명의 기술 적용에 관한 연구)

  • Jung, Byoung-Ho;Joo, Hyung-Kun
    • Journal of Korea Society of Digital Industry and Information Management
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    • v.16 no.4
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    • pp.95-110
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    • 2020
  • The purpose of this study is to empirically examine organizational change for a technological application of the fourth industrial revolution. The theoretical background of this study utilized organizational change management, the fourth industrial revolution, technological innovation, and voluntary acceptance. This research method used structural equations, cluster analysis, and analysis of variance. According to the results of the study, the organizational implement system, organizational leadership, and organizational operating system provided a positive effect on the voluntary technology acceptance of organization members. The voluntary technology acceptance provided a positive effect on the effectiveness of individual task innovation. However, organizational institutionalization among the independent variables did not affect voluntary acceptance. All independent variables except the organizational institutionalization had a partial mediating effect in the mediating effect verification. Meanwhile, The three groups by the cluster analysis were classified as new technology apathy, preference, and anxiety groups, and differences appeared among groups in the importance of organizational change variables. The organizational implement system in the technology apathy group and the organizational operating system in the technology anxiety group have a positive effect on voluntary technology acceptance. The technology preference group shows that a positive effect on organizational leadership and a negative effect on organizational institutionalization for voluntary technology acceptance. This study analyzed the technology application of the fourth industrial revolution in the organization based on the theory of organizational change. There has been reexamined the organizational change theory based on the new technology acceptance by the change of external environment in the fourth industrial revolution and the importance of technology innovation. As a practical implication, firms that are interested in a new technology of the fourth industrial revolution should prioritize preparing an implementation system when designing organizational changes.

Effects of Pilates Reformer Core and Mat Core Exercises on Standing Posture Alignment

  • Sim, Gyeongseop;Kim, Donghoon;Jeon, Hyeseon
    • Physical Therapy Korea
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    • v.29 no.4
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    • pp.282-288
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    • 2022
  • Background: Pilates exercises are used for body shape correction because they can achieve correct posture alignment through spinal stabilization. Objects: This study aimed to determine whether the use of reformers increases the effectiveness of Pilates core exercises on body alignment in standing. Methods: The study included 30 women without known diagnoses of musculoskeletal and neurological disorders or cancer. Those who had taken more than 10 Pilates lessons were excluded. The participants were randomly assigned to either the reformer exercise group or the mat exercise group, and interventional Pilates exercises were performed for 60 minutes a day, three times a week, for a total of 8 weeks. Ten movements of the reformer and mat Pilates core exercise programs were included. Exbody® 9100 MOMI musculoskeletal analysis equipment (Exbody Inc.) was used to assess the alignment of the standing posture in the frontal plane. Results: As a result of comparing the differences within and between the groups before and after the intervention using the two-way mixed analysis of variance test, height differences in the head, pelvis, left and right, shoulders, scapulas, knees, and ankles in the frontal plane after the intervention were found in both groups. For example, the left-right symmetry of the body alignment in the standing posture was significantly improved within each group (p < 0.05). However, no significant difference was found between the groups (p > 0.05). Conclusion: Both the reformer and mat Pilates core exercises were effective for standing posture alignment, which has clinical significance. If an exercise program is developed based on the analysis of movements necessary for posture improvement and the target muscles to be strengthened, the same effect can be achieved only with mat exercise without using the reformer equipment at the beginner stage.

Development of Nursing Clinical Judgment Scale (간호사의 임상판단 측정도구 개발)

  • Kwon, Shi Nae;Park, Hyojung
    • Journal of Korean Academy of Nursing
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    • v.53 no.6
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    • pp.652-665
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    • 2023
  • Purpose: This study aimed to develop a nursing clinical judgment scale (NCJS) and verify its validity and reliability in assessing the clinical judgment of nurses. Methods: A preliminary instrument of the NCJS comprising 38 items was first developed from attributes and indicators derived from a literature review and an in-depth/focus interview with 12 clinical nurses. The preliminary tool was finalized after 7 experts conducted a content validity test based on a data from a preliminary survey of 30 hospital nurses in Korea. Data were collected from 443 ward, intensive care unit, emergency room nurses who voluntarily participated in the survey through offline and online for the verification of the construct validity and reliability of the scale. Results: The final scale comprised 23 items scored on a 5-point Likert scale. Six factors - integrated data analysis, evaluation and reflection on interventions, evidence on interventions, collaboration among health professionals, patient-centered nursing, and collaboration among nurse colleagues - accounted for 64.9% of the total variance. Confirmatory factor analysis supported the fit of the measurement model, comprising six factors (root mean square error of approximation = .07, standardized root mean square residual = .04, comparative fit index = .90). Cronbach's α for all the items was .92. Conclusion: The NCJS is a valid and reliable tool that fully reflects the characteristics of clinical practice, and it can be used effectively to evaluate the clinical judgment of Korean nurses. Future research should reflect the variables influencing clinical judgment and develop an action plan to improve it.

Comparison of fracture strength, surface hardness, and color stain of conventionally fabricated, 3D printed, and CAD-CAM milled interim prosthodontic materials after thermocycling

  • Mesut Yildirim;Filiz Aykent;Mahmut Sertac Ozdogan
    • The Journal of Advanced Prosthodontics
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    • v.16 no.2
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    • pp.115-125
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    • 2024
  • PURPOSE. The purpose of this in vitro study was to investigate the fracture resistance, surface hardness, and color stain of 3D printed, CAD-CAM milled, and conventional interim materials. MATERIALS AND METHODS. A total of 80 specimens were fabricated from auto polymerizing polymethyl methacrylate (PMMA), bis-acryl composite resin, CAD-CAM polymethyl methacrylate resin (milled), and 3D printed composite resin (printed) (n = 20). Forty of them were crown-shaped, on which fracture strength test was performed (n = 10). The others were disc-shaped specimens (10 mm × 2 mm) and divided into two groups for surface hardness and color stainability tests before and after thermal cycling in coffee solution (n = 10). Color parameters were measured with a spectrophotometer before and after each storage period, and color differences (CIEDE2000 [DE00]) were calculated. The distribution of variables was measured with the Kolmogorov Smirnov test, and one-way analysis of variance (ANOVA), Tukey HSD, Kruskal-Wallis, Mann-Whitney U tests were used in the analysis of quantitative independent data. Paired sample t-test was used in the analysis of dependent quantitative data (P < .05). RESULTS. The highest crown fracture resistance values were determined for the 3D printed composite resin (P < .05), and the lowest were observed in the bis-acryl composite resin (P < .05). Before and after thermal cycling, increase in mean hardness values were observed only in 3D printed composite resin (P < .05) and the highest ΔE00 value were observed in PMMA resin for all materials (P < .05). CONCLUSION. 3D printing and CAD-CAM milled interim materials showed better fracture strength. After the coffee thermal cycle, the highest surface hardness value was again found in 3D printing and CAD-CAM milled interim samples and the color change of the bis-acryl resin-based samples and the additive production technique was higher than the PMMA resin and CAD-CAM milled resin samples.

Study on Job Stress and Job Satisfaction of Dental Hygienists in Changwon (창원지역 치과위생사의 직무스트레스와 직무만족에 관한 연구)

  • Lee, Myeong-Ju;Kwon, Sun-Hwa;Goo, Hyo-Jin
    • Journal of Korean Clinical Health Science
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    • v.1 no.3
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    • pp.39-48
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    • 2013
  • Purpose. This study was performed on survey related dental hygienist job stress and job satisfaction, to improve the work efficiency of the dental hygienist and for dental hygienist to eliminate the cause of stress for health promotion and for management to be able to help to finding ways to provide basic data. Method. This survey is based on 235 people who are dental hygienists working in Changwon city from November 1 to November 30 2012, by statistical analysis of collected data using SPSS Win Program 20.0 version t-test, univariate analysis of variance (one-way ANOVA), correlation analysis that performed to determine statistical significance with a significance level of 0.05 was considered. Results. For correlation of job satisfaction and job stress, the job demands, job insecurity, and workplace culture shows a negative correlation. For Correlation of the physical environment, insufficient job control, interpersonal conflict, and organizational system is, lack of reward shows a positive correlation. The less job stress due to Insufficient job control, interpersonal conflict, organizational system, is, the higher job satisfaction due to job demands and workplace culture is.(p <0.05), The higher job stress is, the higher the job satisfaction is(p <0.05). Conclusions. Job satisfaction and job stress may be relevant each other, there fore several measures should be sought to solve insufficient job control, interpersonal conflict, organizational system and the lack of reward, consequently to increase the job satisfaction of dental hygienists.

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The Effects of Emotional Labor on Emotional Exhaustion of School Dietitians : Comparison on Level of Self-efficacy (학교급식 직영 영양사의 감정노동이 감정고갈에 미치는 영향 : 자기효능감 수준에 따른 군집별 분석)

  • Lee, Hae-Young
    • Korean journal of food and cookery science
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    • v.30 no.1
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    • pp.84-91
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    • 2014
  • The purpose of this study was to identify the effects of emotional labor on emotional exhaustion among school dietitians according to the level of their self-efficacy. A survey was administered on 300 school dietitians during September 2012 and a total of 277 usable questionnaires were received. The data were analyzed by using the SPSS 18.0 package program. As a result of principal factor analysis for validity test, 26 variables were classified into one factor for self-efficacy, three factors for emotional labor and one factor for emotional exhaustion with a total variance percentage of 67.371%. Internal consistency was estimated by Cronbach's alpha, which yielded reliability coefficients of 0.922 (self-efficacy), 0.916 (emotional display), 0.806 (surface acting), 0.808 (deep acting) and 0.850 (emotional exhaustion). Subjects were segmented into 2 groups of 'high self-efficacy' (n = 159) and 'low self-efficacy' (n = 118) according to the cluster analysis for self-efficacy variables. The 'high self-efficacy' group exhibited higher education(p < 0.01) and served less lunch meals than other groups (p < 0.05). According to multiple regression analysis, the emotional display proved to be significantly and positively related to emotional exhaustion (${\beta}$=0.319, p<0.001) in high self-efficacy group. However both emotional display (${\beta}$=0.233, p<0.05) and surface acting (${\beta}$=0.262, p<0.01) were positively related to emotional exhaustion in the low self-efficacy group. These results suggest that school dietitians should be more aware of their self-efficacy to relieve the effects of the emotional labor on emotional exhaustion.

Determinants of Intent to Leave among Workers at Long-Term Care Institutions (노인의료복지시설 근무자들의 이직의도 결정요인)

  • Oh, Ji-Young;Seo, Young-Joon;Park, Hyun-Suk
    • The Korean Journal of Health Service Management
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    • v.6 no.1
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    • pp.87-103
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    • 2012
  • The purpose of this study is to investigate the determinants of intent to leave among workers at long-term care institutions in South Korea. The model represents a revision of the Price(2001) model which extends previous research by providing a comprehensive review of the economic, psychological, sociological literature. This study also examined the moderating effects of values toward independent variables on the job satisfaction and organizational commitment. The sample used in this study consisted of 400 workers from 9 long-term care hospitals and facilities nationwide. Data were collected with self-administered questionnaires and analysed using multiple regression analysis and path analysis. The main results of the study were as follows. The variance of job satisfaction and organizational commitment explained by the independent variables used in the study are 74.5% and 76.3% respectively. The results of this study revealed that the following variables have significant negative effects on intent to leave among workers; organizational commitment, job satisfaction, positive affectivity, supervisor support, job significance, job security, job growth. And the following variables have significant positive effects on intent to leave among workers; job opportunity, negative affectivity. This result is same when the moderating role of values were considered in the analysis. Among demographic variables, only age was found to have a significant positive effect on the intent to leave among workers.

Effect of Sample Preparation on Prediction of Fermentation Quality of Maize Silages by Near Infrared Reflectance Spectroscopy

  • Park, H.S.;Lee, J.K.;Fike, J.H.;Kim, D.A.;Ko, M.S.;Ha, Jong Kyu
    • Asian-Australasian Journal of Animal Sciences
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    • v.18 no.5
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    • pp.643-648
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    • 2005
  • Near infrared reflectance spectroscopy (NIRS) has become increasingly used as a rapid, accurate method of evaluating some chemical constituents in cereal grains and forages. If samples could be analyzed without drying and grinding, then sample preparation time and costs may be reduced. This study was conducted to develop robust NIRS equations to predict fermentation quality of corn (Zea mays) silage and to select acceptable sample preparation methods for prediction of fermentation products in corn silage by NIRS. Prior to analysis, samples (n = 112) were either oven-dried and ground (OD), frozen in liquid nitrogen and ground (LN) and intact fresh (IF). Samples were scanned from 400 to 2,500 nm with an NIRS 6,500 monochromator. The samples were divided into calibration and validation sets. The spectral data were regressed on a range of dry matter (DM), pH and short chain organic acids using modified multivariate partial least squares (MPLS) analysis that used first and second order derivatives. All chemical analyses were conducted with fresh samples. From these treatments, calibration equations were developed successfully for concentrations of all constituents except butyric acid. Prediction accuracy, represented by standard error of prediction (SEP) and $R^2_{v}$ (variance accounted for in validation set), was slightly better with the LN treatment ($R^2$ 0.75-0.90) than for OD ($R^2$ 0.43-0.81) or IF ($R^2$ 0.62-0.79) treatments. Fermentation characteristics could be successfully predicted by NIRS analysis either with dry or fresh silage. Although statistical results for the OD and IF treatments were the lower than those of LN treatment, intact fresh (IF) treatment may be acceptable when processing is costly or when possible component alterations are expected.