• 제목/요약/키워드: Coefficient of Variance

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Development and Validation of an Analytical Method for Glucuronolactone in Energy Drinks by Hydrophilic Interaction Liquid Chromatography-electrospray Tandem Mass Spectrometry

  • Oh, Mi Hyune;Lim, Moo Song;Chai, Jeung Young;Kim, Eun Jung;Cho, Joong Hoon;Lim, Chul Joo;Choi, Sun Ok
    • Journal of Food Hygiene and Safety
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    • v.32 no.2
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    • pp.89-95
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    • 2017
  • A rapid, sensitive analytical method for glucuronolactone in beverages was developed and validated using hydrophilic interaction liquid chromatography coupled to electrospray ionization tandem mass spectrometry (HILIC-ESI-MS/MS). To determine the optimum analytical conditions for glucuronolactone, three different kinds of HILIC columns and two mobile phases with different pH values were examined. An amide-bonded stationary phase with a pH 9 acetonitrile-rich mobile phase was the best condition in terms of column retention, ESI-MS/MS response area, and signal-to-noise ratio. After extraction, glucuronolactone was separated through the HILIC amide column and detected by negative ESI-MS/MS in selected reaction monitoring (SRM) mode. Nine energy drinks sold in Korea were spiked with glucuronolactone at a concentration of 5 ng/mL; the Monster $Energy^{TM}$ sample showed the smallest peak area and its signal-to-noise ratio was used for method validation. Good linearity was obtained in the concentration range from 20 to 1500 ng/mL with a correlation coefficient > 0.998. The developed method had a limit of detection (LOD) of 6 ng/mL and a limit of quantitation (LOQ) of 20 ng/mL. The recovery of this method at concentration of 20, 100, 500, and 1000 ng/mL was 96.3%-99.2% with relative standard deviations (RSD) of 1.6%-14.0%. A reproducibility precision assessment at concentration of 100 and 500 ng/mL was carried out among three laboratories. The recovery of that evaluation was 95.1%-102.3% with RSD of 2.7%-7.0%. An analysis of variance indicated that there was no difference between the recovery results of the three laboratories at the 5% significance level. The validated method is applicable to inspecting beverages adulterated with glucuronolactone in Korea.

Development of the Multidimensional Scale of Addictive Behavior for Adolescents (청소년 중독행동의 다차원적 척도 개발)

  • Park, Hyun-Sook;Jung, Sun-Young
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.13 no.8
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    • pp.3597-3609
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    • 2012
  • Purpose: This study was done to develop the multidimensional scale of addictive behavior for adolescents. Methods: The process involved construction of a conceptual framework, initial items, verification of content validity, selection of secondary items, and extraction of final items. The participants were 636 adolescents in six middle schools and four high schools. Results: Seventy items were selected for the final scale, and categorized 8 factors explaining 56.5% of total variance. The factors were labeled as game addictive behavior, shopping addictive behavior, mobile phone addictive behavior, nicotine addictive behavior, television addictive behavior, gambling addictive behavior, alcohol addictive behavior, and internet addictive behavior. The scores for the scale were significantly correlated with addictive personality and self-control. Cronbach's alpha coefficient for the 70 items was .94. Scale scores identified adolescents as addictive behavior group, risk group, and average group. Conclusion: The above findings indicate that the multidimensional scale of addictive behavior for adolescents has good validity and reliability when used with adolescents. More importantly, it provides the first step toward developing a addiction prevention program. Additionally the scales provide an education or guideline, and proper physical and mental health management of youth in research and practice for the promotion of education.

Comparing Validity of Body Mass Index, Waist to Hip Ratio, and Waist Circumference to Cardiovascular Disease Risk Factors in Korean Elderly (한국노인에서 심장혈관계 질환 위험인자에 대한 비만지표인 체질량지수, 허리-엉덩이둘레비, 및 허리둘레의 타당도 비교)

  • Moon Hyun-Kyung;Kim Eu-Gene
    • Journal of Nutrition and Health
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    • v.38 no.6
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    • pp.445-454
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    • 2005
  • The purpose of this study was to compare the validity of obese index among body mass index (BMI), waist to hip ratio (WHR), and waist circumference (WC) and to determine which is the best in relation to cardiovascular disease (CVD) risk in Korean elderly more than 65 ages. Data from the 1998 Korean Health and Nutrition Survey were used (n=1017). Anthropometric indices and CVD risk factors were measured, and chi-square test, analysis of variance following duncan's multiple range test, partial correlation analysis, and Receiver Operator Characteristic (ROC) curves were used in the analysis. Anthropometric values were decreased in both male and female when ages were goes up. In female elderly, it specially showed the characteristics of upper body fat and systolic blood pressure risk (p<0.05). Among life style factors the current smokers were prevalent in obese male (p<0.05), but not prevalent in female having obese or upper body fat. Also, person with upper body obesity have more exercise than that of normal group (p<0.01). Mean BMI values of the current smoker was lower than that of normal group in both sexes (p<0.01). Mean BMI value of person with other risk factors were higher than that of normal groups (p<0.05). Among 7 CVD risk factors in partial correlation analysis, WC had the highest correlation coefficient in 5 in male, whereas BMI in 4 in female. In ROC analyses of 12 risk factors and health conditions, the largest area under curve of obese indices for risk factors were WC>WHR>BMI in male and BMI>WHR>WC in female. The optimal cutoff values of each index (BMI : WHR : WC) for one or more risk factors were 19.02 : 0.84 : 71.3 in male and 19.04 : 0.88 : 85.6 in female. In conclusion, Most Korean elderly showed non-obese and abdominal obesity likewise other Asians. Also CVD risk factors were prevalent in Korean elderly within normal limits of obese indices. Therefore the upper body fat indices reflected in the aged whose muscle mass is replaced by fat must be used as an indicator of CVD risk together with BMI. Although WHR was the worst index based on partial correlation analysis and so located between BMI and WC in ROC curve analysis in both sexes, it need to be use with WC to screen the cardiovascular risk group.

Health Promoting Life style, Hardiness and Gender Role Characteristics in Middel-Aged Women (중년여성의 건강증진 생활방식, 강인성 성역할 특성의 관계)

  • Suh, Yeon-Ok
    • Women's Health Nursing
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    • v.2 no.1
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    • pp.138-157
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    • 1996
  • Recently, there has been increase perception of health promotion with development of the economic state and science. Individual's responsibility and psychosocial factors have impacted on the individual's lifestyle. Health promotion can be maintained or improved through changes of lifestyle of individuals. Also, there has been supported results of health behavior health has been focused on menopausal symptom and reproductive organ. Until recently, little research has been available on the health or health care of midlife women. The purpose of this study was to explain relationship between health promoting lifestyle and hardiness, gender role characteristics. A total of 254 items of data were obtained from randomly selected subjects. The data collected from the interviews were analyzed using SPSS, yielding frequency, mean. t-test, ANOVA, Pearson Correlation, Stepwise multiple regression. The result of this study are as follows : 1) For the health promoting lifestyle, the mean score was 116.3, the highest score was nutrition(3.30) and interpersonal support(2.86), the lowest score was exercise(1.68). The highest subscale for the hardiness was committment(2.44). Also for the gender role characteristics was higher than median score(37.8). 2) There was a statistically difference the demographic variables. A total health promotion lifestyle was predicted by income and marriage satisfaction, hardiness was predicted by education, income, marriage satisfaction, support person and gender role characteristics was predicted by education. 3) With regard to the relationship among health promoting lifestyle, hardiness, gender role characteristics, the correlation coefficient between health promoting lifestyle and hardiness was r=-.48, p<.001. Also there were significant correlation between health promoting lifestyle and gender role characteristics(r=.22, p<.01), hardiness and gender role characteristics(r=-.39, p<.001). 4) A stepwise multiple regression analysis was done on the total health promoting lifestyle score using the demographic variables, hardiness subscale and gender role characteristics for independent variables. A total of 25% of the variance was explained inthe total health promoting lifestyle by the control, challenge and marriage satisfaction. In conclusion, hardiness and gender role characteristics were engaged in health promoting activity in midlife women. This study also provides new information about the health practices that midlife women report they practice. Therefore, nursing intervention to increase women's health have to be planed program that consider on the basis the results of this study.

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Reliability Evaluation of Rubber Wheel and Steel Wheel for Wheel Tracking Test of Bituminous Concretes (역청 콘크리트 반복주행시험에서 고무바퀴와 강재바퀴의 신뢰성 비교 연구)

  • Hong, Joon-Pyo;Doh, Young-Soo;Kim, Kwang-Woo
    • International Journal of Highway Engineering
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    • v.7 no.2 s.24
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    • pp.97-107
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    • 2005
  • Since the purpose of wheel tracking test is to find out relative difference of mixture's rut resistance, the wheel is an important part in the test for obtaining a consistent output. This study is performed to examine efficiency of different wheel material, rubber and steel in wheel tracking test. The rubber was inserted as a ring on the outer face of the steel wheel, and thickness of rubber ring was 15mm and 7.5mm and 0mm (steel wheel without rubber), making the total outer diameter 200mm. The objective of this study was to select reliable wheel material type in wheel tracking test at $60^{\circ}C$ based on variance in output (rut depth and dynamic stability) and correlation with SD (deformation strength). The result of regression analysis of rut depth with Sd showed that $R^2$ values of wheel rubber thickness of 15mm, 7.5mm and 0mm were 0.7, 0.8 and over 0.9, respectively. In a case of steel wheel (0mm), the highest $R^2$ value was 0.9569. Therefore, the wheel without rubber ring was the best in output consistency level and coefficient of determination $(R^2)$ with deformation strength. Therefore, the steel wheel without rubber ring is suggested as the best choice for wheel tracking test of asphalt concrete.

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A Study on the Relation between the Number of First Aid Training and the Performance of Facilities Security Personnel (시설보안요원의 응급처치교육이수와 직무수행 관계에 관한 연구)

  • Kim, Sin-Hye;Han, I-Jun
    • Korean Security Journal
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    • no.59
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    • pp.91-108
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    • 2019
  • The purpose of this study is to investigate the relationship between the number of first aid training and safety performance. The researcher's questionnaire consisted of three variables: necessity of first aid education, application to security practice, and improvement of job satisfaction. In this study, Chronbach's Alpha coefficients were calculated to measure the internal validity for the reliability of the questionnaire. In order to verify the validity of the measured variables, exploratory factor analysis was carried out using the Berimax rotation method. The mean variance extracted AVE and the conceptual reliability CR value of the measurement result variables were both above the allowable reference value of 0.5 and it was judged to be a good test in terms of intensive validity. As a result of the hypothesis test, the standardization coefficient was 1.106 for 'necessity of first aid education ⇒ applied to security practice work', and 'applied to security work practice ⇒ improvement of job satisfaction' was 1.063 and the relationship of hypothesis 1 hypothesis 2 was significant (+), Respectively. Therefore, in order to increase the job satisfaction of security related workers, it is necessary to support first aid education and to receive first aid education.

Generation of calibration standard gases using capillary gas divider: uncertainty measurement and method validation (다중 모세관을 이용한 교정용 표준가스의 제조: 불확도와 유효성 평가)

  • Lee, Sangyun;Hwang, Eun-Jin;Jung, Hye-Ja;Lee, Kwang-Woo;Chun, Ki-Joon
    • Analytical Science and Technology
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    • v.19 no.5
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    • pp.369-375
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    • 2006
  • Calibration gas mixtures were prepared using dynamic volumetric method according to ISO 6145-5 and the uncertainty was evaluated. Ten identical capillaries with 0.25 mm in inner diameter and 50 cm in length were applied in this system. Dilution ratio of parent gas was determined by the number of capillaries that passes parent gas and that passes balance gas through. Capillaries were made of Teflon which had good chemical stability against adsorption of gaseous substances. Mechanical valves were introduced in this system in order to minimize the thermal effect of solenoid valves. Concentration of prepared gases were compared with master grade standard gases in cylinders made by RiGAS Co. and calibration of the instrument were completed using comparison method according to ISO 6143. Experimental results showed that the coefficient of variance of diluted oxygen standard gases showed less then 0.2% in most dilution range, that of diluted hydrogen sulfide standard gases showed less then 1.0%. Therefore, it is proven that the standard gases prepared by this system are appropriate to be used as a calibration standards in ambient monitoring, etc.

Joint Characteristics in Sedimentary Rocks of Gyeongsang Supergroup (경상누층군 퇴적암의 절리 특성 연구)

  • Chang, Tae-Woo;Son, Byeong-Kook
    • The Journal of Engineering Geology
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    • v.19 no.3
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    • pp.351-363
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    • 2009
  • Two orthogonal joint sets develop well only in sandstone beds in the sandstone-mudstone sequences of Gumi and Dasa outcrops within Cretaceous Gyeongsang Basin. And various joint data are similar in the beds of the same thickness in both outcrops, meaning that the joint sets were homogeneously produced by extensional deformation in the same regional stress field. Most of joints in the sandstone beds are orthogonal to, and confined by bed boundaries, which are believed to be formed by hydrofracturing during consolidation after burial. Two orthogonal joint sets are considered to be almost coeval on the basis of mutual abutting relationship which makes up fracture grid-lock and a product of rapid switching of ${\sigma}_2$ and ${\sigma}_3$ axes with constant ${\sigma}_1$ direction oriented to vertical. The joint sets in the sandstone beds show planar surfaces, parallel orientations and regular spacing, with joint spacing linearly proportional to bed thickness. The spacing distributions of the joints seem to correspond to log-normal to almost normal distribution in most of the beds. But multilayer joints do not display regular spacing and dominant size. Either joint set in this study is characterized by a high level of joint density and a saturated spacing distribution as indicated by the mode/mean ratio values and the Cv(coefficient of variance) values. Joint aperture tends to increase with the vertical length of the joints controlled by bed thickness.

The Determinants of a Health Promoting Lifestyle in High school students (고등학생의 건강증진 생활양식과 관련 요인)

  • Hong, Woi-Hyun;Kim, Chung-Nam
    • Research in Community and Public Health Nursing
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    • v.10 no.2
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    • pp.330-346
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    • 1999
  • This descriptive correlational study was conducted to identify the variables related to a health promoting lifestyle in high school students. 304 high school students and 189 vocational high school students living in Taegu city were selected by a convenience sampling method. The data were collected by self-reported questionnaires from August 24 to September 4, 1998. Pender and others' Health Promoting Lifestyle Profile, Shere et al's. Self-Efficacy scale, Wallston et al.'s Internal Health Locus of Control scale, Wares' Health self rating scale and Cohen & Hoberman's Social support scale were used. The data were analyzed by using descriptive statistics, Pearson correlation coefficient, t-test, MANOVA, ANOVA. Tukey verification and Stepwise multiple regression with an SAS program. The results of this study were as follows: 1. The average score of a health promoting lifestyle performance was 2.38(SD=.36) of a 4 point scale .Self-actualization (mean = 2.80. SD = .60). interpersonal support(mean = 2.73, SD=.47), health responsibility (mean=1.53, SD=.47), nutrition(mean=2.64, SD=.63), exercise(mean=2.71. SD=.72) and stress management(mean=2.37, SD=.58) were also analyzed. 2. The combination of self-efficacy, social-support, internal health locus of control. father's educational level and perceived health status explained 37.97% of the variance in health promoting lifestyles. 3. A Health promoting lifestyle showed significant positive correlations with self efficacy(r=.5173. p=.0011), perceived health status(r=.254, p=.001) and internal health locus of control(r=.321. p=.001). 4. According to sex(t=7.38. p=.006). economic state(F=6.62, p=.00l), Father's educational level(F=4.25, p=.005), mother's educational level(F=6.94. p=.000l), the grade of educational performance(F=3.74, p=.024), sleeping hours(F=3.47. p=.032) and social support(F=40.76, p=.0001). there were significant differences and modifying factors in health promoting lifestyles. On the basis of the above findings. self-efficacy in cognitive factors, and social support in modifying factors were identified as the variables which explained most of Pender's health-promotion model. Nursing strategies enhancing self-efficacy and social support which have a more significant effect on health promoting lifestyles should be developed. Further research is required to find out the factors influencing health pormoting lifestyle of high school students.

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The Study on Health Promoting Lifestyle of the Elderly (노인의 건강증진 생활양식에 관한 연구)

  • 송영신;이미라;안은경
    • Journal of Korean Academy of Nursing
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    • v.27 no.3
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    • pp.541-549
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    • 1997
  • This study was done to describe health promoting lifestyle and determine affecting factors in elderly based on the Heath Promotion Model by Pender. Cognitive-perceptual factors that were included in this study were self-efficacy and hardiness. Modifying factors were demographic characteristics (sex, age, partner, previous illness, education level. income and religion). The specific purpose of this study was to examine the relationships of self-efficacy, hardiness and the demographic chasteristics to health promoting lifestyle and to determine causal factors affecting the elderly. The subjects were a volunteer sample of 98 elderly in one city in? The instruments for this study were Health Promoting Lifestyle Profile(47items, 4scale), Health Related Hardiness Scale(22i1ems, 6scale), general Self-Efficacy Scale(13i1ems, 5scale). Frequency, percentage, t-test, ANOVA, Pearson's correlation coefficient and Stepwise Multiple regression technique with SAS program were used to analyse the data. The Results of the study are as follows : 1) The average item score for the health promoting lifestyle was 2.63, the highest score on the subscales was interpersonal support (M=3.3), followed by self-actulization(M=2.9), nutrition(M=2.8), stress management(M=2.7), health responsibility(M=2.1) with the lowest bring exercise(M=2.0) 2) A significant difference between education level, income, religion and health promoting lifestyle were found. 3) All of the subscales on health promoting lifestyle were positively related to total hardiness (r=0.330, p<0.001). The hardiness subscale of control was positively related to self-actulization(r=0.276, p<0.01), and commitment was positively related to self-actualization(r=0.315, p<0.001), exercise /nutrition(r=0.245, p<0.01), interpersonal support(r=0.278, p<0.01), stress management(r=0.250, p<0.01). Challenge was positively related to self-actualization(r=0.315, p<0.001), exercise /nutrition(r=0.245, p<0.01). There was no significant correlation between self-efficacy and all of the subscales of health promoting lifestyle. Self-efficacy showed a significant correlation only with control(r=0.469, p<0.001), comittment(r=0.507, p<0.001), challenge (r=0.489, p< 0.001). 4) Comittment, self-efficacy and income explained 25.01% of the variance for the total health promoting lifestyle. The results of this study show that commitment, self efficacy and income predicted the health promoting lifestyle of the elderly. So health promoting programs that increase commitement and self-efficacy should be developed to promote a healthy lifestyle of the elderly, especially those who have low income.

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