• Title/Summary/Keyword: paired-t tests

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Tests for Incomplete Paired Data (불완전한 짝자료에 대한 검정법)

  • 이승묵;박진경;박태성
    • The Korean Journal of Applied Statistics
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    • v.12 no.2
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    • pp.415-432
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    • 1999
  • 짝자료(paired data)에서 결측값이 발생했을 때에 이 자료를 처리할 수 있는 여러통계검정 방법들을 고찰해보았다. 결측값들을 어떻게 처리하는 지에 따라서 다섯 가지 방법으로 분류해 보았고, 이 방법들이 짝 t-검정에 미치는 효과를 모의실험을 통해 비교해 보았다. 결측값들에 대한 세 종류의 메카니즘을 고려하여 검정크기와 검정력을 구하였다.

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Radiographic changes of mandibular cortical bone in bisphosphonate drug holiday

  • Lee, Dae-Hoon;Seo, Ja-In;Song, Seung-Il;Lee, Jeong-Keun
    • Journal of the Korean Association of Oral and Maxillofacial Surgeons
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    • v.48 no.4
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    • pp.219-224
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    • 2022
  • Objectives: There have been few studies to date on the residual effect of bisphosphonate. This study investigated the radiographic changes of mandibular cortical thickness upon bisphosphonate drug holiday. Materials and Methods: This retrospective study includes 36 patients diagnosed with MRONJ (medication-related osteonecrosis of the jaw) at Ajou University Dental Hospital in 2010-2021. All patients stopped taking bisphosphonate under consultation with the prescribing physicians. Panoramic radiographs were taken at the start of discontinuation (T0), 12 months after (T1), and 18 months after (T2) discontinuation of bisphosphonate, respectively. Mental index and panoramic mandibular index were calculated using Ledgerton's method. Paired t-tests were used to analyze differences over time. Results: The difference in indices (mental index and panoramic mandibular index) between T0 and T1 was not statistically significant (paired t-test, P>0.05). However, the difference in these indices between T1 and T2 was statistically significant (paired t-test, P<0.05). Conclusion: The cortical thickness of the mandible decreased in the late stage (after 18 months) as observed by panoramic radiograph.

Strength Modeling of Mechanical Strength of Polyolefin Fiber Reinforced Cementitious Composites

  • Sakthievel, P.B.;Ravichandran, A.;Alagumurthi, N.
    • Journal of Construction Engineering and Project Management
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    • v.4 no.2
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    • pp.41-46
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    • 2014
  • RCC consumes large quantities of natural resources like gravel stone and steel, and there is a need to investigate on an innovative material that utilizes limited quantities of natural resources but should have good mechanical strength. This study deals with the experimental investigation of strength evaluation of cementitious composites reinforced with polyolefin fibers from 0% to 2.5% (with interval of 0.5%), namely Polyolefin Fiber Reinforced Cementitious Composites (PL-FRCC) and developing statistical regression models for compressive strength, splitting-tensile strength, flexural strength and impact strength of PL-FRCC. Paired t-tests (for each PL fiber percentage 0 to 2.5%) bring out that there is significant difference in compressive and splitting-tensile strength when curing periods (3, 7, 28 days) are varied. Also, a strong relationship exists between the compressive and flexural strength of PL-FRCC. The proposed mathematical models developed in this study will be helpful to ascertain the mechanical strength of FRCC, especially, when the fiber reinforcing index is varied.

Effects of Cardiopulmonary Resuscitation Education Using a PC Skill-Reporting System on the Knowledge, Self-Efficacy and Skill Performance Ability of Nursing Students (PC Skill-Reporting System을 활용한 심폐소생술 교육이 간호학생의 지식, 자기효능감, 술기수행능력에 미치는 효과)

  • Kim, Ran;Chae, Min-Jeong
    • The Korean Journal of Health Service Management
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    • v.9 no.1
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    • pp.133-144
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    • 2015
  • The Purpose of this study was to identify the educational effects of cardiopulmonary resuscitation using a PC skill-reporting system on the knowledge, Self-efficacy and skill performance ability of nursing students. The Participants were 57 nursing students from G metropolitan city, an experimental group of 29 subjects, and a control group of 28 students who were randomly sampled. Data were collected from 3 to 12 July of, 2013, and theory education and skill exposure programs for the experimental and control groups were conducted for 60 min. three times a week. The, PC skill-reporting system was used only with the experimental group. The collected data were analyzed with SPSS/WIN version 20.0 using ${\chi}^2$-tests, Fisher's exact probability tests, paired t-tests and t-tests. In the comparison of the two groups, the knowledge(t=-2.39, p=.022), self-efficacy (t=-3.45, p<.001) and skill performance ability(t=-2.52, p=.012) of the experiment group were significantly higher than those of the control group. Therefore, the adoption of instructional methods using a PC skill-reporting system is required to maximize the effects of cardiopulmonary resuscitation instruction.

Dose Sol Raises Consumer Prices? (음력설이 소비자물가에 영향을 미치는가?)

  • Lee, Geung Hui
    • The Korean Journal of Applied Statistics
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    • v.12 no.2
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    • pp.387-387
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    • 1999
  • The traditional holiday, Sol which is based on a lunar calendar, falls in January orFebruary and makes it difficult to analyze time series data accurately. To analyze whetherSol raises consumer prices or not, RegARIMA models and paired t tests are used. It isfound that Sol raises consumer prices of food products significantly, but So1's effects onconsumer prices of all items are not significant.

APPLYING FUZZY MATHEMATICS TO QUANTIFYING HUMAN RESPONSES

  • R.C.Steinlage;T.E.Gantner;Lim, P.Y.W.
    • Proceedings of the Korean Institute of Intelligent Systems Conference
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    • 1993.06a
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    • pp.1362-1365
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    • 1993
  • Fuzzy mathematics is used to elicit and evaluate human psychophysical responses in panel tests. The fundamental instrument used is a bar graph whose data is then converted to a paired comparison matrix. Form this matrix we use the theory of Perron and Froebenius to obtain an eigenvalue and eigenvector which indicates not only the panelist's comparitive responses but also the consistency of the responses from that panelist. Tests were done to evaluate the procedure.

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Effects of 6 weeks of Weight Training and Complex Training on Y-balance Test in High School Soccer Players

  • Dong Geun LEE;Jae Woong KIM;Young Jae MOON;Hwang Woon MOON
    • Journal of Sport and Applied Science
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    • v.8 no.2
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    • pp.13-18
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    • 2024
  • Purpose: The purpose of this study is to determine the effects of a 6-week weight training and complex training program on the Y-balance test (YBT) in high school soccer players. Research design, data, and methodology: This study included 26 high school soccer players from City S. Subjects were divided into a weight training group (WTG: n=13) and a complex training group (CTG: n=13) based on their willingness to participate without medical problems. The YBT measured anterior (AT), posteromedial (PM), posterolateral (PL), and composite scores (CS), and was measured twice: before the start and after the end of training. The data were analyzed using the SPSS 25.0 statistical program to compare pre- and post-training using paired-t tests, between training groups using independent-t tests, and left-right comparisons using independent-t tests. Results: Training resulted in a significant pre- to post-training change in PL in the left foot WTG group (p<.05), with no significant change in the other measures. There were no significant differences between training groups and between left and right sides. Conclusion: To improve YBT in high school soccer players, a program to improve ankle and hip mobility and strength should be added along with improving large muscle strength through weights and comflex training.

A Study of Preschooler's Stress Coping Strategies Depending on Task and Temperament (과제 및 기질에 따른 유아의 스트레스 대처 전략)

  • Kim Jimin;Yoo An Jin
    • Journal of the Korean Home Economics Association
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    • v.43 no.1 s.203
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    • pp.177-189
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    • 2005
  • This study investigated 3- and 5-year-old preschoolers' stress coping strategies depending on tasks, and whether preschoolers' stress coping strategies in each task depended on their temperament types. Subjects were 96 3- and 5-year-old preschoolers selected from three day-care centers in Seoul, Kounggi. A Parent Temperament Questionnaire for preschooler was used, and the coping strategies which each preschooler showed in task with perceived controllable, task with perceived uncontrollable were recorded by a video camera. Preschoolers' stress coping strategies recorded by a video camera were transcribed and analyzed according to the categories the researcher generated. Data were analyzed by paired t-tests and t-tests. As a results, there was a significant differences in preschoolers' stress coping strategies depending on the tasks and a significant temperament type difference in the preschoolers' stress coping strategies in each task.

The change of muscle dysmorphia through bodybuilding for 12 weeks : Korean college students

  • Kim, Deokjin
    • International Journal of Advanced Culture Technology
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    • v.7 no.2
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    • pp.1-6
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    • 2019
  • The central purpose of the current research is to identify how 12-week bodybuilding exercise affects muscle dysmorphia. The research subjects consisted of an experimental group and a control group, each with 16 freshmen at college. MDI(muscle dysmorphic inventory), developed by Schlundt, Woodford, Brownlee(2000) was utilized to collect relevant data, which was analyzed by PASW 18.0. An independent two sample t-test was conducted to see whether there exists any significant difference between the two groups in the pre- and the post-tests. A paired t-test, in turn, was performed to identify whether there is any difference between the two tests for each group. The statistical significance level was set at p<.05. It was found that the experimental group marked a higher level of muscle dysmorphia than the control group in the pre-test. It was also found that muscle dysmorphia of the experimental group increased in the post-test, while no significant difference was manifested in the control group in the post-test.

The Effects of a Support Group Intervention on the Burden of Primary Family Caregivers of Stroke Patients (집단적 지지 간호중재 프로그램이 뇌졸중 환자 가족 수발자의 부담감에 미치는 효과)

  • Yoo, Eun-Kwang;Jeon, Sang-Hee;Yang, Jeong-Eun
    • Journal of Korean Academy of Nursing
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    • v.37 no.5
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    • pp.693-702
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    • 2007
  • Purpose: The purpose of this study was to develop and evaluate the effects of a support group intervention on the burden of primary family caregivers of stroke patients. Method: A nonequivalent control group pretest-posttest design was used. The subjects were 36 primary family caregivers of stroke patients [experimental(N=18) and control(N=18) groups] in a neurosurgery ward of a university hospital. The experimental group members participated in six sessions of a support group intervention for two weeks and the degree of their caregiving burden was evaluated. Data was analyzed by Chi-square tests, t-tests, and paired t-tests using SPSS 10.0. Result: The experimental group had a significantly lower total burden score (t=2.06l, p= .047)and sub-scales of emotional(t=-3.319, p= .002), time-dependent(t=-2.045, p= .049) and developmental(t=-2.656, p= .012) burden scores than the control group, while no significant differences were found in physical, social or financial burden scores between the two groups. Within the experimental group, there was a significant decrease in physical(t=2.507, p= .023), emotional(t=4.754, p= .000), social(t=2.932, p= .009), time- dependent(t=5.015, p= .000) and developmental(t=7.541, p= .000) burden scores but not the financial burden score. Conclusion: The results suggest that a support group intervention can be utilized as an effective nursing program to reduce the burden of primary family caregivers of stroke patients.