• Title/Summary/Keyword: modified t-test

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The Immediate Effects of Hamstring Eccentric Exercise and Static Stretching on Trunk Forward Bending (즉각적인 뒤넙다리근 편심성 운동과 정적 스트레칭이 몸통 전방 굽힘에 미치는 영향)

  • Kim, Tae-eun;Choi, Bo-ram
    • Physical Therapy Korea
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    • v.26 no.3
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    • pp.32-41
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    • 2019
  • Background: Limitations in hip flexion caused by tight hamstrings lead to excessive lumbar flexion and low back pain. Accordingly, many studies have examined how to stretch the hamstring muscle. However, no study has focused on the effect of hamstring eccentric exercise for tight hamstrings on trunk forward bending. Objects: We compared the short-term effect of hamstring eccentric exercise (HEE) and hamstring static stretching (HSS) on trunk forward bending in individuals with tight hamstrings. Methods: Thirty individuals with tight hamstrings participated in the study. The subjects were randomly allocated to either a HEE or HSS group. To determine whether the hamstrings were tight, the active knee extension (AKE) test was performed, and the degree of hip flexion was measured. To assess trunk forward bending, subjects performed the fingertip to floor (FTF) and modified modified Schober tests, and the degree of trunk forward bending was measured using an inclinometer. We used paired t-tests to compare the values before and after exercise in each group and independent t-tests to compare the two groups on various measures Results: The FTF test results were improved significantly after the exercise in both groups, and AKE for both legs increased significantly in both groups. There was no significant difference in the hip angles, mmS test results, or degree of trunk forward bending between groups after the exercise. No test results differed significantly between the two groups at baseline or after the exercise. Both groups increased hamstring flexibility and trunk forward bending. Conclusion: HSS and the HEE groups increased hamstring flexibility and trunk forward bending. However, HEE has additional benefits, such as injury prevention and muscle strengthening.

Concentration dependent dielectric properties of Barium Titanate/Polyvenylidene Fluoride (PVDF) and (Bi0.5Na0.5)0.94Ba0.06TiO3/Poly(VDF-TrFE) composite

  • Roy, Ansu K.;Ahmad, Z.;Prasad, A.;Prasad, K.
    • Advances in materials Research
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    • v.1 no.4
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    • pp.285-297
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    • 2012
  • The present study addresses the problem of quantitative prediction of effective complex relative permittivity of Barium Titanate/Polyvenylidene Fluoride (PVDF) and $(Bi_{0.5}Na_{0.5})_{0.94}Ba_{0.06}TiO_3$/Poly(VDF-TrFE) biphasic ceramic-polymer composites. Theoretical results for effective relative permittivity derived from several dielectric mixture equations were fitted to the experimental data taken from the works of Prasad et al. (2010), Wang et al. (2004), Takenaka et al. (1991) and Yamada et al. (1982). The study revealed that out of the different test equations, only a few equations like modified Rother-Lichtenecker equation, Dias-Dasgupta equation or Rao equation for the real part and Bruggeman equation for the imaginary part of complex permittivity well fitted the corresponding experimental results. In the present study, some of the equations were used in their original forms, while some others were modified by choosing suitable shape-dependent parameters in order to get reasonably good agreement with experimental results. Besides, the experimental results have been proposed in the form of a mathematical model using first order exponential growth, which provided excellent fits.

The Influence of Job Characteristics and Job Stress on Children's Hospital Nurses' Turnover Intention (직무특성과 직무스트레스가 아동병원 간호사의 이직의도에 미치는 영향)

  • Kim, Se-Young;Back, Seong-Hee
    • The Journal of the Korea Contents Association
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    • v.16 no.4
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    • pp.100-113
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    • 2016
  • Purpose: This study was performed to investigate the influence of children's hospital nurses' job characteristics and job stress on turnover intention. Method: The subjects were 148 nurses who have been working in 6 children's hospitals located in G city. Measurement tools used for this study included job characteristics were created by Lee, and modified by Hong, and job stress tool developed Kim & Ku and modified by Choi. And the tools used for assessing turnover intention were created by Mobley and Becker and modified by Kim. The collected data was analyzed using descriptive statistics, the independent t-test, one-way ANOVA, Pearson' Correlation and regression on SPSS 21.0 program. Result: Job challenge and job fitness among the sub-areas of job characteristics, job stress and salary were identified as factors influencing turnover intention. These factors explained 36.5% of variance of turnover intention. Conclusion: In conclusion, this results can be used to help the children's hospitals creates an environment where nurses can enhance Job challenge and job fitness also, reduce job stress which lead to turnover rate and turnover intention.

The Effect of a Modified Side-Bridge Exercise on the Thickness of Trunk Muscles in Healthy Adults (수정된 측면 교각운동이 정상 성인 몸통근육의 두께에 미치는 영향)

  • Park, Jae-Cheol;Kim, Yong-Nam
    • PNF and Movement
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    • v.19 no.1
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    • pp.127-135
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    • 2021
  • Purpose: The purpose of this study was to determine the effect of the side-bridge exercise on the thicknesses of the external and internal obliques, the transverse abdominis, and the erector spinae, which are some of the trunk muscles of healthy adult males and females. Methods: There were 30 subjects divided into two groups with 15 subjects in the modified side-bridge exercise group and 15 subjects in the bridge exercise group. The changes in each variable were analyzed before the exercise, after three weeks, and after six weeks of exercise using a two-way repeated analysis of variance. The significance level was set at 0.05. When there was any interaction between the time of measurement and each group, a paired t-test was conducted to find the difference within groups and an independent-sample t-test was conducted to find the difference between groups. The significance level for both tests was set at 0.01. Results: There was a significant difference in the external and internal obliques and the erector spinae according to changes over time and the interactions between the time and groups (p < 0.05). However, there was a significant difference in the transverse abdominis only according to the interaction between the length of times (p < 0.05). Conclusion: The study results indicated that the modified side-bridge exercise significantly increased the thickness of the external and internal obliques and the erector spinae. This suggests the usability of the exercise in lumbar stabilization exercises in future studies and clinical fields.

Effect of Flow Direction on Two-Phase Flow Distribution of Refrigerants at a T-Junction

  • Tae Sang-Jin;Cho Keum-Nam
    • Journal of Mechanical Science and Technology
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    • v.20 no.5
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    • pp.717-727
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    • 2006
  • The present study experimentally investigated the effect of flow direction and other flow parameters on two-phase flow distribution of refrigerants at a T-junction, and also suggested a prediction model for refrigerant in a T-junction by modifying previous model for air-water flow. R-22, R-134a, and R-410A were used as test refrigerants. As geometric parameters, the direction of the inlet or branch tube and the tube diameter ratio of branch to inlet tube were chosen. The measured data were compared with the values predicted by the models developed for air-water or steam-water mixture in the literature. We propose a modified model for application to the reduced T-junction and vertical tube orientation. Among the geometric parameters, the branch tube direction showed the biggest sensitivity to the mass flow rate ratio for the gas phase, while the inlet quality showed the biggest sensitivity to the mass flow rate ratio among the inlet flow parameters.

Accuracy Improvement for Measurement of Heat of Fusion by T-history Method (T-history법에 의한 잠열량 측정 정확도의 향상)

  • 박창현;백종현;강채동;홍희기
    • Korean Journal of Air-Conditioning and Refrigeration Engineering
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    • v.15 no.8
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    • pp.652-660
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    • 2003
  • T-history method, measuring heat-of-fusion of phase change material (PCM) in sealed tubes, has the advantages of a simple experimental device and no requirements in sampling process. However, a degree of supercooling used in selecting the range of latent heat release and neglecting sensible heat during the phase change process can cause significant errors in determining the heat of fusion in the original method, which has been improved in order to predict better results by us. In the present study, the modified method was applied to a variety of PCM such as paraffin and lauric acid having very small or no supercooling with a satisfactory precision. Also the selection of inflection point and temperature measurement position was fumed out not to affect the accuracy of heat-of-fusion significantly. As a result, the method can provide an appropriate means to assess a new developed PCM by cycle test even if a very accurate value cannot be obtained.

The Climacteric Symptoms and Quality of Life in Climacteric Women according to Hormone Replacement Therapy (호르몬 대체요법에 따른 갱년기여성의 갱년증상과 삶의 질)

  • Kim, Og-Mi;Lee, Young-Sook
    • Women's Health Nursing
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    • v.7 no.4
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    • pp.642-656
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    • 2001
  • The purpose of this study is to find the difference of the climacteric symptoms and quality of life according to hormone replacement therapy (HRT) in climacteric women. The research design was a descriptive survey with questionaries. A convenience sample of 181 climacteric women aged 45-65 who had climacteric symptoms were selected in Kwangju city, Korea. Sixty-six climacteric women among those subjects were receiving HRT at K university hospital in Kwangju city. Data were collected by the interview with questionaries from Feb 3. 1999 to March 25, 1999. Climacteric symptoms were measured using scores developed by Neugarten(1965) and modified by Park(1989), and the quality of life scale related to climacteric symptoms developed by Hildtich(1996) and modified Kim(1998). Data were analyzed by $x^2$-test, t-test, ANOVA and Pearson's correlation procedures, using SAS/win PC+. The results were as follows ; 1. No statistically significant differences were found between the receiving HRT group and not receiving HRT group in demographic, obstetrical and health related characteristics. 2. There were no significant difference on the climacteric symptoms between the group of women receiving HRT (score 2.4) and the group of women who were not (score 2.6) except psychological area (t= 2.407, p= 0.017). 3. The quality of life of the group of women receiving HRT was significantly higher than that the group of women who were not (t=2.151, p=.032). 4. The quality of life of the group of women receiving HRT were high scores There were significantly high of the quality of life in the vaso-motor change area (t=2.634, p= 0.009), psycho-social change area (t=3.239, p=0.001), and physical change area (t=2.031, p=0,043) in the group of receiving HRT compared to not receiving HRT group. 5. The variables showed significantly differences on the degree of climacteric symptoms of the group of women not receiving HRT were the subjective health state (t=15.81, p=0.000), age (t=7.50, p=0.007), feeling of menopause (t=30.88, p=0,000) and climacteric periods (t=8.66, p=0.003), and receiving HRT were number of para (t=3.95, p=0.050) and feeling of menopause (t=3.94, p=0.050). 6. The variables showed significantly difference on the quality of life of the group of women not receiving HRT were the subjective health state (t=4.14, p=0.044) and feeling of menopause (t=10.86, p=0.001). 7. There were significantly positive correlations between the climacteric symptoms and the quality of life in climacteric women (r=0.512, p=0.000).

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Control of Food Pests by $CO_{2}$ Modified Atmosphere: Effects of Packing Materials and Exposure Time on the Mortality of Tribolium castaneum and Plodia interpunctella (고농도 탄산가스 충전에 의한 식품 해충 방제: 거짓쌀도둑거저리와 화랑곡나방의 살충효과에 미치는 노출시간과 식품포장 재질의 영향)

  • Na, Ja-Hyun;Nam, Young-Woo;Ryoo, Mun-Il;Chun, Yong-Shik
    • Korean journal of applied entomology
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    • v.45 no.3 s.144
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    • pp.363-369
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    • 2006
  • Effects of three packing materials and exposure time on the mortality of Plodia interpunctella and Tribolium castaneum were studied using $CO_{2}-modified$ atmosphere control. Materials used were triple layered craft paper (KKK), triple layered craft paper with one laminate coating layer (KLK), and triple layered craft paper with one HD film coating layer (KHK). In the test balls (${\phi}1.2\;m$) containing 85% $CO_{2}-modified$ atmosphere, concentration of $CO_{2}$ in small packing envelopes ($9.8{\times}9.8cm$) made of the materials after one day was higher in KKK ($26.67{\pm}0.58%$) than KLK ($23.33{\pm}0.58%$) or KHK ($20.67{\pm}0.58%$). Both P. interpunctella and T. castaneum showed higher mortality in KKK than in either KLK or KHK Similar results were obtained by larger space ($9{\times}4{\times}3m$) and packing volume (20 kg) studies. The effect of the packing materials was clearer on T. castaneum more tolerant to $CO_{2}$ than P. interpunctella. Regression of the insect mortality on cumulative concentration time (${\int}_{0}^{t}c{\times}tdc{\approx}{\sum}concentration{\times}time$) was highly significant. Control of P. interpunctella and T. castaneum by $CO_{2}-modified$ atmosphere were discussed in relation to packing materials, cumulative concentration time of $CO_{2}$ and food products.

Effects of simulation-based training on the critical care nurses' competence of advanced cardiac life support (시뮬레이션 교육이 간호사의 전문심장소생술 수행능력에 미치는 효과)

  • Back, Chi-Yun
    • Journal of Korean Critical Care Nursing
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    • v.1 no.1
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    • pp.59-71
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    • 2008
  • Purpose: This study was to identify the effects of simulation-based training for advanced cardic life support on the competence of nurses in critical care settings. Methods: In this study, a nonequivalent control pretest-post test quasi-experimental design was used. Data were collected from May 1 to June 1, 2006 at one general hospital in W city. Among 40 nurses in critical care settings, twenty were assigned to the experimental group and twenty to the control group. Nurses in the experimental group received simulation-based training for advanced cardiac life support. Measurement tool were ACLS related knowledge and skills developed by AHA & Mega Code (2005) and some items were modified. The collected data were statistically processed using SPSS version 12.0 for Windows, and analyzed using descriptive statistics, $X^2$test, t-test, paired ttest, Pearson correlation coefficients. Results: 1) Hypothesis 1“: Nurses who received simulationbased training would have more knowledge of advanced cardiac life support than nurses who received traditional training”, was supported (t=11.51, p=.00). 2) Hypothesis 2: “Nurses who received simulation-based training would have better advanced cardiac life support skills than nurses who received traditional training”, was supported (t=2.38, p=.00). Conclusion: Simulation-based training for advanced cardiac life support is an effective strategy for increasing the competence of nurses in advanced cardiac life support in critical care settings.

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Effect of Proprioceptive Neuromuscular Facilitation Stretching on Pain, Hip Joint Range of Motion, and Functional Disability in Patients with Chronic Low Back Pain

  • Kim, Beomryong;Kang, Taewoo;Kim, Dahee
    • Physical Therapy Rehabilitation Science
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    • v.10 no.2
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    • pp.225-234
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    • 2021
  • Objective: We aimed to identify the effects of proprioceptive neuromuscular facilitation (PNF) stretching on pain, hip range of motion, and functional disability in patients with chronic low back pain. Design: Randomized controlled trial Methods: In total, 45 patients with chronic low back pain were randomly divided into a conventional stretching group (n=22) and a PNF stretching group (n=23). Both interventions were performed three times per week for 6 weeks. Assessments were made using the visual analog scale, Flexion-Abduction-External Rotation test, modified Thomas test, prone hip extension test, and Oswestry disability index before and after the 6-week intervention period. We conducted a paired t-test to compare the within-group findings before and after the intervention. An independent t-test was used to compare the between-group differences. The statistical significance level was set at α=0.05, for all variables. Results: Both groups showed significant improvements in pain, hip range of motion, and functional disability after the intervention (p<0.05). A significant difference was observed in pain, hip range of motion, and functional disability in patients belonging to the PNF stretching group (p<0.05). Conclusions: This study provides evidence that the application of PNF stretching can effectively reduce pain and improve hip range of motion and functional disability in patients with chronic low back pain.