• Title/Summary/Keyword: Paired T-Test

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A Comparison of Dose-Response Assessments for CMR Materials in the Workplace (작업장에서 취급하는 CMR물질의 용량반응평가 방법 비교)

  • Lee, Kyung Hwa;Choi, Han Young;Kim, Chi Nyon;Roh, Young Man;Choi, Hee Jin;Park, Chae Ri
    • Journal of Korean Society of Occupational and Environmental Hygiene
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    • v.28 no.1
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    • pp.51-60
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    • 2018
  • Objectives: Currently, there is only limited knowledge regarding the hazard of low-level exposure to CMR materials in workplaces. To overcome this limitation, a reference concentration for workers($RfC_w$) from among the risk assessment tools proposed by the US EPA is widely used to set a provisional workplace exposure level(PWEL) for CMR materials for which there are no established Korea Occupational Exposure Limits(KOELs) or subjective chemicals for work environment measurements as regulated by Korea Ministry of Employment and Labor(KMOEL). A simple European calculator of derived no effect level(SECO-DNEL) as proposed by REACH can also be used in place of $RfC_w$ to set the PWEL for chemicals. This study was performed to test the acceptability of using SECO-DNEL as an alternative to $RfC_w$ when setting a PWEL for low-level exposures. Methods: The $RfC_w$ and DNEL for the five CMR materials of dinitrogen oxide, catechol, 2-phenoxy ethanol, carbitol, and carbon black were calculated using the dose-response assessments of the US EPA for $RfC_w$ and REACH guidance for SECO-DNEL, respectively. They were compared using paired t-tests to determine the statistical differences between them. Results: For the five chemicals, the $RfC_w$ were 2.53 ppm, 0.10 ppm, 1.73 ppm, 1.66 ppm, and $0.05mg/m^3$, respectively, while the SECO-DNEL were 2.01 ppm, 0.11 ppm, 1.83 ppm, 1.77 ppm, $0.14mg/m^3$, respectively. There was no statistically significant difference between $RfC_w$ and SECO-DNEL. Conclusions: This study suggests that the SECO-DNEL could be applied in place of $RfC_w$ to set a PWEL for low-level exposure to chemicals, especially CMR materials. To further ensure the reliability of SECO-DNEL as an alternative tool, more chemicals should be applied for calculation and comparison with $RfC_w$.

A Study on the Ratio Analysis as a Tool for Evaluating Financial Performance (병원재정 평가를 위한 비율분석에 관한 연구)

  • Chae, Young-Moon;Yun, Jung-Hyun;Lee, Hae-Jong
    • Journal of Preventive Medicine and Public Health
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    • v.19 no.2 s.20
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    • pp.213-223
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    • 1986
  • Ratio analysis allows a hospital to evaluate its own performance over time and to compare its performance with that of other hospitals. For this study, three types of ratio analysis were conducted based on some data on hospitals in Massachusetts. First, Key ratios influencing financial performance were identified using discriminant analysis. Second, the financial structures of the teaching and the non-teaching hospitals were compared using ratios and multiple comparison method. Third, the effects of the prospective reimbursement law of the state on financial performance were examined using ratios and paired t-test. The purpose of the law is to reduce hospital costs by setting the revenue ceiling prior to the effective budget year. The findings of this study were as follows: 1) When hospitals were divided into three groups, according to their operating income, only profitability ratios showed a consistent difference among the groups. 2) In the discriminant analysis, five ratios were selected: current ratio, operating margin, return on assets, fixed assets turnover, and inventory turnover. They are the key ratios to be monitored periodically for the purpose of evaluating the financial performance of hospitals. 3) When teaching hospitals were compared with non-teaching hospitals, acid ratio, days of cash on hand, and inventory turnover were statistically significant before the law went into effect, whereas only fixed assets turnover and inventory turnover were significant afterward. Contrary to previous studies, profitability ratios of teaching hospitals were higher than those of non-teaching hospitals, although the differences were not statistically significant. 4) When the ratios between the two periods (before and after the law) were compared, three profitability ratios (operating margin, return on assets, and return on equity) were significant for teaching hospitals, whereas three activity ratios (total assets turnover, fixed assets turnover, current assets turnover) were significant for non-teaching hospitals. Furthermore, while both total operating revenue and expenses were decreased, net operating income was increased, due to a greater decrease in total operating expenses. This shows that the law can indeed, simultaneously, achieve both a reduction in costs as well as an improvement in the financial situation of hospitals.

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Effects of Walking and Behavior Modification Program on Body Composition, Physical Fitness and Metabolic Syndrome Related Factors in Obese Girls (걷기운동과 행동수정 프로그램이 비만여중생의 체조성, 체력 및 대사증후군 관련인자에 미치는 영향)

  • Kim, Jong-Won;Jeon, Jae-Young;Kim, Tae-Un
    • Journal of Life Science
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    • v.17 no.12
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    • pp.1744-1753
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    • 2007
  • The purpose of this study was to provide obese middle school girls with walking and behavior modification program(WBMP) by investigating effects of the exercise on their body composition(BC), physical fitness(PF) and metabolic syndrome(MS). Analysis result of the difference between before and after the exercise(paired and independent t-test) was acquired by measuring BC, PF and MS for 12 weeks(60min/day, three a week). 24 Volunteers were 14 years over ${\geq}223.64kg/m^2$ and 15 years over ${\geq}24.00kg/m^2$. In the body composition, waist circumference(WC), body fat mass(BFM), %fat, arm muscle circumference(AMC), total body water(TBW), physical score(PS) were significant difference between the exercise group(EG) and the control group(CG), also including all factors in PF. The components of metabolic syndrome were significant difference between EG and CG, but HDL-C, systolic & diastolic blood pressure were no difference. The metabolic syndrome factors by separate of waist girth were no difference between EG and CG, but BMI, diastolic blood pressure were significant difference. The prevalence of metabolic syndrome was 4 of 24(16.7%) before intervention, but it dropped from 2 to 1 after intervention in WBMP. The components of metabolic syndrome was distributed a big WC>low HDL-C>high TG>hypertension. The changes of AMC, We, PS, BW, 50m run and BFM effect the factors on BMI(35%), WHR(waist-hip ratio, 69%), HDL-C(42%), fasting blood glucose(65%), HOMA-IR index(34%) and systolic blood pressure(39%) respectively. There were significantly increased in breakfast frequency, walking steps, and meal eating period, but decreased in snacks and eating out in exercise group.

Temperature Difference Between the Brain and Axilla in Patients Under Hypothermia (저체온요법 치료 환자에서의 두개강내와 액와부의 온도차이)

  • Yoo, Do-Sung;Kim, Dal-Soo;Huh, Pil-Woo;Cho, Kyung-Suck;Kim, Jae-Gun;Park, Chun-Kun;Kang, Joon-Ki
    • Journal of Korean Neurosurgical Society
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    • v.30 no.7
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    • pp.903-906
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    • 2001
  • Objective : The brain temperature is about $0.4-1^{\circ}C$ higher than that of the other peripheral body area. But most of these results have been obtained in normothermic condition. The objective of this study is to evaluate the temperature difference between the brain and axilla, in patients under hypothermia. Methods : Sixty-three patients(37 women and 26 men) who underwent craniotomy with implantation of the thermal diffusion flowmetry sensor were included in this study. The temperature of the cerebral cortex and axilla was measured every 2 hours, simultaneously. The patient group was divided according to axillary temperature hyperthermia( over $38^{\circ}C$), normothermia($36-38^{\circ}C$) and hypothermia(under $36^{\circ}C$). Total 1671 paired sample data were collected and analyzed. Results : The temperature difference between the cerebral cortex and the axilla was $0.45{\pm}1.04^{\circ}C$ in hyperthermic patients, $0.97{\pm}1.1^{\circ}C$ in normothermic patients and $1.04{\pm}0.81^{\circ}C$ in hypothermic patients. The temperature difference has statistical significance in each group(unpaired t-test, p<0.05). Conclusion : From our study the temperature difference between the brain and the axilla in hypothermic condition increased more than that of normothermic state. And in hyperthermic condition, the temperature difference decreased.

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An Effect of Low Back Pain Relieving Program on the Back Muscle Strenght, Intensity of Pain, Disability Level in Elementary School Women Teacher (요통완화프로그램이 만성 요통호소 여교사의 배근력, 통증정도, 기능장애에 미치는 효과)

  • Choi, Soon-Young
    • Women's Health Nursing
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    • v.6 no.1
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    • pp.117-128
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    • 2000
  • The purpose of this study was to examine the effect of low back pain relieving program on back muscle strength, intensity of pain, low back disability level in elementary school teachers who have low back pain. subjects were elementary school women teachers who worked at eight elementary school located in Seoul. Intended subjects size were seventy consist of thirty-four experimental group(three schools) and thirty-six control group(five schools), but actual subjects size was forty-four. Among the forty-four patients subjects, twenty-three were experimental group receiving health education about right postures, etiologies of low back pain, diagnosis of low back pain and exercise program composed of muscle strengthening exercise, stretching exercises and twenty-one were control group. During the 8 weeks program, the subjects were received two times education and six times group exercise practices in 1st week and three times per week group exercise practices, two times education in other 7 weeks. This study as carried out from April 1, 1999 to June 30, 1999. Back muscle strength was measured by back muscle strength measuring machine and the intensity of pain were measured by the Visual Analogue Scale(VAS), and level of disability was measured by Oswestry low back pain disability scale. Study measurements were taken before and after 8 week exercise program. Data were analyzed using paired t-test, and ANCOVA. The results were summarized as follows. 1. After low back relieving program, back muscle strength was increased significantly(p=0.000) and there was significant difference in back muscle strength change between experimental group and control group(p=0.002). 2. After low back pain relieving program, pain on anterior bending, pain on posterior bending were decreased significantly than measurements before the program(p=0.000 p=0.000) and there was significant difference in pain on anterior bending and posterior bending change between experimental group and control group(p=0.000, p=0.000). 3. After low back pain relieving program, Oswestry disability scale scores were decreased significantly(p=0.000, p=0.000) but there was no significant difference in Oswestry disability score change between experimental group and control group.

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Accuracy of 24-hour Diet Recalls for Estimating Energy Intake in Elderly Men using the Doubly Labeled Water Method (남자 노인에서 에너지 섭취 조사를 위한 24시간 회상법의 정확도 평가 -이중표식수법을 사용하여-)

  • Jeon, Ji-Hye;Go, Na-Young;Lee, Mo-Ran;Ndahimana, Didace;Kim, Eun-Kyung
    • Korean Journal of Community Nutrition
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    • v.23 no.6
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    • pp.516-524
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    • 2018
  • Objectives: This study assessed the accuracy of the 24-hour diet recall method for estimating the energy intake of elderly men using the doubly labeled water as a reference method. Methods: Seventeen subjects (mean age $72.5{\pm}3.9years$), who maintained the same body weight during the two weeks study period, were included in this study. Three 24-hour diet recalls (two weekdays and one weekend) were obtained over a 14 day period to estimate the mean energy intake. The total energy expenditure was measured over the same 14 days using the doubly labeled water method. The total energy intake and total energy expenditure were compared by paired t-test. Results: The total energy intake from the 24-hour diet recalls method was $2536.7{\pm}350.6kcal/day$, and the total energy expenditure from the doubly labeled water method was $2659.8{\pm}306.8kcal/day$. The total energy intake was slightly under-reported by $-123.2{\pm}260.8kcal/day$ (-4.4%). On the other hand, no significant difference was observed between the total energy intake and total energy expenditure of the subjects (p=0.069). The percentage of accurate predictions was 64.7%. The correlation between the total energy intake and total energy expenditure was statistically significant (r=0.697, p<0.005). Conclusions: The present study supports the use of the 24-hour diet recall method to estimate the mean energy intake in elderly men group. More studies are needed to assess the validity of 24-hour diet recall method in other population groups, including elderly women, adults and children.

Pre-service Early Childhood Teachers' Improvement of Perception on Teaching Professionalism through Early Childhood Teaching Practice Experience (교육실습을 통한 예비 유아교사들의 <수업전문성>에 대한 인식 및 변화 탐색 연구)

  • Lee, Seung Eun
    • Korean Journal of Child Education & Care
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    • v.19 no.2
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    • pp.1-17
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    • 2019
  • Objective: The objective of this study was to explore the perception and its improvement of pre-service teachers regarding teaching professionalism. The subjects of this study were 41 university students who experiencing early childhood teaching practice and 41 their cooperating teachers. Methods: In order to examine perception and its improvement on teaching professionalism, teaching professionalism scale for pre-service early childhood teachers (TPSECT) that was 33 items was administrated. Data were analysed paired t-test and contents analysis. Results: First, early childhood teaching practice experience affected positive effects on the four subordinate areas of teaching professionalism: , , , and improved perception of teaching professionalism. Second, student teachers were developing teaching professionalism, in a course of early childhood teaching practice which consisted of performing teaching real children in the field, evaluating and feedback of cooperating teacher, self-reflection and re-instruction. Conclusion/Implications: For improving pre-service teachers' professionalism, except a teaching practice subject, it is necessary to open various subjects that provide practical experiences, such as, teaching real children, observing actual class. This suggests that more experiential and practical in-service education program will be demanded.

An Educational Needs Analysis for Job Applicants Relating to the Core Competency Used in National Competency Standards(NCS-Based) Recruitment (국가직무능력표준(NCS) 기반 채용에서 직업기초능력에 대한 취업준비생의 인식 분석)

  • Kim, Hyeyeong;Beak, Song Yi;Youn, Jaehee;Park, Inn Woo
    • Journal of the Korea Academia-Industrial cooperation Society
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    • v.20 no.7
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    • pp.133-144
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    • 2019
  • The purpose of this study is to analyze the difference in perceptions of job applicants on core competency in the recruitment environment based on National Competence Standards(NCS), and also to obtain information relating to the seeking of employment and employment education plans. A survey and paired t-test were conducted on 355 job applicants of vocational colleges and four-year universities. Through these applicants, the difference between the current level and level of importance dependent on areas of core competency was analyzed. In addition, IPA analysis was conducted in order to confirm the educational necessity in this area. As a result, there were significant differences between the current level and level of importance in all 10 areas. IPA analysis confirmed that educational needs are prioritized. As a result, it was found that the areas which should be strengthened in both groups were interpersonal ability, communication ability, numerical ability, problem solving ability, and self-development ability. The area recognized as being in 'a state of excess' was resource management ability. As a result of checking the necessity levels of the two groups, it was found that job applicants of vocational colleges had to strengthen their problem solving ability, and the applicants of four-year universities had to intensify their communication ability, interpersonal ability, and information ability.

Effects of Kinesiology tape in ankle joint of quadriceps and hamstring muscles activation during squat exercise (스쿼트 운동 시 발목 관절에 키네시오 테이프의 적용이 넙다리 네갈래근과 뒤넙다리근의 활성에 미치는 영향)

  • Park, Jae-heung;Lee, Seung-hee;Kim, So-jung;Cho, Seung-ju;Park, Hyun-hee;Lee, Yu-jin;Sim, Hye-ji;Choi, Bo-ram
    • Journal of Korean Physical Therapy Science
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    • v.28 no.2
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    • pp.57-64
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    • 2021
  • Background: During squat exercises, Ankle joint stability during squat movement transfers forces produced by unstable supports or various loads to the leg joints and trunk, reducing the risk of injury; therefore, a reference is needed for correct ankle joint posture during squat exercises. The purpose of this study was to examine the effect of ankle joint stability on quadriceps femoris and hamstring activation during squat exercises. Design: Quasi-experiment one group pretest-posttest design. Methods: The participants in this study were 20 volunteers who performed squat exercises with and without kinesiology tape. We measured quadriceps femoris and hamstring activation using surface electromyography. The ankle joint was stabilized with kinesiology tape using the ankle balance taping (ABT) method. A paired t-test was performed to compare differences between taping conditions. Results: Vastus medialis and vastus lateralis activation were greater following squat exercises with kinesiology tape than without; however, the difference was not significant. Medial and lateral hamstring activation was not significantly different between taping conditions. Conclusion: Although it is difficult to maintain stability using kinesiology tape alone, ankle joint stability is believed to affect quadriceps femoris muscle activity, which increases the effectiveness of the squat exercise.

Effects of Combined Exercise on Body Composition and Cardiovascular fitness in Sarcopenic Obesity Elderly Women (16주간 복합운동이 Sarcopenic Obesity 여성고령자의 신체조성 및 심폐체력에 미치는 영향)

  • Jung, Joo-Ha;Yang, Jum-Hong
    • 한국노년학
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    • v.32 no.3
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    • pp.703-714
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    • 2012
  • The purpose of this study was to analyze the effects of combined exercise on body composition and cardiovascular disease risk factors in sarcopenic obesity elderly women. The subjects for the study were 21 obesity elderly women over 65 years old . They were divided into two groups, the sarcopenic obesity group(n=9) and non-sarcopenic obesity group(n=12). The variables of body composition and cardiovascular fitness were measured in all the subjects before and after 16-week combined exercise. All data was analyzed by two-way ANOVA with repeated measures, and paired t-test by using SPSS 18.0. The findings of this study were as follows; 1. Effects on body composition The relationship between sarcopenia and body composition were only significant for the group ${\times}$ time interaction in FFM. In the sarcopenic obesity elderly women, % body fat significantly decreased and sarcopenia reduced by 30%, but there were no significant changes in the FFM and ASM. On the other hand, the non-sarcopenic obesity elderly women significantly decreased % body fat and significantly increased FFM and ASM. 2. Effects on cardiovascular fitness Both groups significantly increased V˙ O2peak. The most important finding in this study was that sarcopenic obesity elderly women showed delayed effects of a 16-week combined exercise on FFM and ASM compared to the non-sarcopenic obesity elderly women. However, the further studies might need to confirm these results with both genders, different age groups, and various exercise types.