• Title/Summary/Keyword: Chi-square and Kolmogorov-Smirnov test

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Length-biased Rayleigh distribution: reliability analysis, estimation of the parameter, and applications

  • Kayid, M.;Alshingiti, Arwa M.;Aldossary, H.
    • International Journal of Reliability and Applications
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    • v.14 no.1
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    • pp.27-39
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    • 2013
  • In this article, a new model based on the Rayleigh distribution is introduced. This model is useful and practical in physics, reliability, and life testing. The statistical and reliability properties of this model are presented, including moments, the hazard rate, the reversed hazard rate, and mean residual life functions, among others. In addition, it is shown that the distributions of the new model are ordered regarding the strongest likelihood ratio ordering. Four estimating methods, namely, method of moment, maximum likelihood method, Bayes estimation, and uniformly minimum variance unbiased, are used to estimate the parameters of this model. Simulation is used to calculate the estimates and to study their properties. Finally, the appropriateness of this model for real data sets is shown by using the chi-square goodness of fit test and the Kolmogorov-Smirnov statistic.

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Classical and Bayesian methods of estimation for power Lindley distribution with application to waiting time data

  • Sharma, Vikas Kumar;Singh, Sanjay Kumar;Singh, Umesh
    • Communications for Statistical Applications and Methods
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    • v.24 no.3
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    • pp.193-209
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    • 2017
  • The power Lindley distribution with some of its properties is considered in this article. Maximum likelihood, least squares, maximum product spacings, and Bayes estimators are proposed to estimate all the unknown parameters of the power Lindley distribution. Lindley's approximation and Markov chain Monte Carlo techniques are utilized for Bayesian calculations since posterior distribution cannot be reduced to standard distribution. The performances of the proposed estimators are compared based on simulated samples. The waiting times of research articles to be accepted in statistical journals are fitted to the power Lindley distribution with other competing distributions. Chi-square statistic, Kolmogorov-Smirnov statistic, Akaike information criterion and Bayesian information criterion are used to access goodness-of-fit. It was found that the power Lindley distribution gives a better fit for the data than other distributions.

A Comparative Study on the Effects on Urinary Incontinence between Pelvic Floor Muscle Exercise and Magnetic Stimulation Therapy (지역사회 요실금 여성의 골반저근운동과 자기장자극 효과비교)

  • Cho, Myung-Sook;Kang, Hae-Young
    • Research in Community and Public Health Nursing
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    • v.19 no.4
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    • pp.696-703
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    • 2008
  • Purpose: To Perform a randomized comparative study investigating the effects of Pelvic Floor Muscle Exercise(PME) and Magnetic Stimulation Therapy(MST) and to identified the problems in each of PME & MST Method: Forty-nine patients with mild stress incontinence were randomly assigned to either of two treatment groups (24 patients in the PME group and 25 in the MST group). The PME group had a video exercising program for 40 times every day during 6 weeks. The MST group was treated with BioCon-2000TM, 2times/ week for six weeks. Pre-test and post-test were performed by Prineometer, 1-hour pad test. and Jackson's BFLUTS questionnaire of Jackson. Collected data were analysed using SAS 9.1 by frequency, Kolmogorov-Smirnov Z. Chi Square-test, t-test, Fisher Exact probability test, Paired t-test, and Wilcoxon's rank sum test. Results: In comparison between before and after PME and MST, statistically significant difference was observed in maximal vaginal pressure, duration of vaginal contraction, amount of urine, and symptom of urination. In the comparison of the effectiveness between PME & MST, only the maximal of vaginal pressure (Z=2.58, p= .010) was significantly different. Conclusion: The factor more effective in the MST group than in the PME group was high compliance.

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The Extreme Value Analysis of Deepwater Design Wave Height and Wind Velocity off the Southwest Coast (남서 해역 심해 설계 파고 및 풍속의 극치분석)

  • Kim, Kamg-Min;Lee, Joong-Woo;Lee, Hun;Yang, Sang-Yong;Jeong, Young-Hwan
    • Proceedings of the Korean Institute of Navigation and Port Research Conference
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    • v.29 no.1
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    • pp.245-251
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    • 2005
  • When we design coastal and harbol facilities deepwater design wave and wind speed are the important design parameters. Especially, the analysis of these informations is a vital step for the point of disaster prevention. In this study, we made and an extreme value analysis using a series of deep water significant wave data arranged in the 16 direction and supplied by KORDI real-time wave information system ,and the wind data gained from Wan-Do whether Station 1978-2003. The probability distributions considered in this characteristic analysis were the Weibull, the Gumbel, the Log-Pearson Type III, the Normal, the Lognormal, and the Gamma distribution. The parameter for each distribution was estimated by three methods, i.e. the method of moments, the maximum likelihood, and the method of probability weight moments. Furthermore, probability distributions for the extreme data had been selected by using Chi-square and Kolmogorov-Smirnov test within significant level of 5%, i,e. 95% reliance level. From this study we found that Gumbel distribution is the most proper model for the deep water design wave height off the southwest coast of Korea. However the result shows that the proper distribution made for the selected site is varied in each extreme data set.

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The Effects of Aerobic Exercise Therapy on Physical Functions in the Elderly (에어로빅 운동 프로그램이 노인의 신체적 기능에 미치는 효과)

  • Jung, Sook-Hee;Chung, Kyung-Hee
    • Research in Community and Public Health Nursing
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    • v.21 no.2
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    • pp.252-262
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    • 2010
  • Purpose: Designed to examine the effects of aerobic exercise therapy on elders' physical functions. Methods: Selected from an elderly welfare center in an agricultural district located in N City. Thirty seven elders were selected in the experimental group and 38 in the control group, and all the subjects aged over 65. Collected data were statistically analyzed by SPSS/PC 12.0 Win. Detailed data analysis methods were Chi-square, Fisher's exact test, Kolmogorov-Smirnov test, t-test, Mann-Whitney u-test, paired t-test, and Wilcoxon's rank sum test. Results: The first hypothesis "The experimental group who had the aerobic exercise therapy will have greater development in lower leg muscular strength compared to the control group" was supported (t=8.95, p<.001). The second hypothesis "Aerobic exercise therapy participants will show greater development in lower leg endurance" was supported (t=6.12, p<.001). The third hypothesis "Aerobic exercise therapy participants will show greater development in flexibility" was supported (U=49.00, p<.001). The forth hypothesis "Aerobic exercise therapy participants will show greater development in balance" was supported (U=322.00, p<.001). Conclusion: The aerobic exercise therapy showed positive effects on physical functions of the elderly in a rural area.

The effect of community based participatory obesity management program in obese school children (학령기 비만아동을 위한 지역사회 참여형 비만관리 프로그램의 효과)

  • Cho, In-Sook;Ryu, Hyun-Sook
    • Journal of the Korean Applied Science and Technology
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    • v.34 no.4
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    • pp.737-745
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    • 2017
  • The aim of this study was to develop a community based participatory obesity control program and measure the effects of the program on obesity, exercise habit, eating habit and life habits among obese elementary school children. The community based participatory obesity control program was provided for the experimental group of $4^{th}$ grade elementary school students for 10 weeks. The program included obesity related health educations and counseling once a week, jump rope classes twice a week and folk game classes held once a week. Method: There were 24 students with obesity in the experimental and 27 in the control groups. The collected data were analyzed by the Kolmogorov-Smirnov test, ${\chi}^2$-test, independent t-test and repeated measure ANOVA. Results: After 10weeks of participation in the program, the experimental group showed significantly lower Body Mass Index (p<.001) and waist hip ratio (p=.036), significantly higher exercise habit (p=.004), eating habit (p=.003) and life habit (p=.001) than those in the control group. Conclusion: This study provides evidence that community based participatory obesity management program is effective nursing intervention for managing child obesity.

Effect of a simulation-based program for post-operative care of emergency patients (응급환자의 수술 후 관리를 위한 시뮬레이션기반 교육프로그램의 효과)

  • Chae, Min-Jeong;Choi, Soon-Hee;Kim, Jeoung-Suk
    • The Korean Journal of Emergency Medical Services
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    • v.18 no.3
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    • pp.91-104
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    • 2014
  • Purpose: This study aimed to confirm the effects of a simulation-based program on knowledge and clinical performance in the post-operative management of emergency patients. Methods: This was a pre- and post-research design with a nonequivalent control group and randomly sampled 29 experimental and control groups, respectively from nursing department juniors for 4 weeks from September of 2014. The experimental group received lectures, team study, team simulation, and debriefing in post-operative management of simulation-based emergency patients and control group conducted in the traditional lecture-type setting. Educational learning effects were measured by using the knowledge and clinical performance measurement tools of 15 and 20 items, respectively. Data were analyzed by using the SPSS program, including frequency, ratio, and results from the Chi-square test, Fisher's exact test, Kolmogorov-Smirnov test, t-test. Results: Our research results indicate that, the experimental group showed significantly higher knowledge and clinical performance score compared with the control group. Conclusion: We confirmed that education on post-operative management of simulation-based emergency patients was an effective educational method to improve the knowledge and clinical performance of nursing students.

Effects of an Action Learning based Creative Problem-Solving Course for Nursing Students (액션러닝 교수설계에 의한 창의적 문제해결 교과의 학습성과)

  • Jang, Keum Seong;Kim, Nam Young;Park, Hyunyoung
    • Journal of Korean Academy of Nursing Administration
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    • v.20 no.5
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    • pp.587-598
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    • 2014
  • Purpose:This study was conducted to identify the effects of an action learning based creative problem-solving (CPS) course on problem solving, creativity and team-member exchange in nursing students. Methods: A quasi-experimental study applying a non-equivalent control group pre-post design was employed. Sophomore nursing students (32 in the experimental group and 33 in the control group) were recruited from a university in G-city, Korea. Problem solving, creativity and team-member exchange were measured for the pretest and posttest using self-report questionnaires. Kolmogorov-Smirnov test, Chi-square, Fisher's exact test, t-test, and ANCOVA with SPSS/Win 20.0 program were used to analyze the data. Results: The scores for problem solving, creativity and team-member exchange in the experimental group were significantly higher than those of the control group. Conclusion: Results of this study indicate that an action learning based CPS course is an effective teaching method to improve nursing students' competencies. In the future longitudinal studies are needed to assess the long term effects of the course.

Optimal Reservoir Operation Models for Paddy Rice Irrigation with Weather Forecasts (I) - Generating Daily Rainfall and Evaporation Data- (기상예보를 고려한 관개용 저수지의 최적 조작 모형(I) -일강수량.일증발량 자료발생-)

  • 김병진;박승우
    • Magazine of the Korean Society of Agricultural Engineers
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    • v.36 no.1
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    • pp.63-72
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    • 1994
  • The objective of the study is to develop weather generators for daily rainfall and small pan evaporation and to test the applicability with recorded data. Daily rainfall forecasting model(DRFM) was developed that uses a first order Markov chain to describe rainfall seque- nces and applies an incomplete Gamma function to predict the amount of precipitation. Daily evaporation forecasting model(DEFM) that adopts a normal distribution function to generate the evaporation for dry and wet days was also formulated. DRFM and DEFM were tested with twenty year weather data from eleven stations using Chi-square and Kolmogorov and Smirnov goodness of fit tests. The test results showed that the generated sequences of rainfall occurrence, amount of rainfall, and pan evaporation were statistically fit to recorded data from eleven, seven, and seven stations at the 5% level of significance. Generated rainfall data from DRFM were very close in frequency distri- bution patterns to records for stations all over the country. Pan evaporation for rainy days generated were less accurate than that for dry days. And the proposed models may be used as tools to provide many mathematical models with long-term daily rainfall and small pan evaporation data. An example is an irrigation scheduling model, which will be further detailed in the paper.

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Evaluation of Reasonableness of the Recommended Spraying Amount Equation for De-icing Chemicals (도로 제설제 권장 살포량 산정식의 적정성 평가)

  • Kim, Jin Guk;Yang, Choong Heon
    • International Journal of Highway Engineering
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    • v.19 no.4
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    • pp.9-18
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    • 2017
  • PURPOSES : This study evaluates the reasonableness of the recommended amount of deicing chemicals based on historical data for snow removal. The result can be used to aid decision-making for the reservation of cost-effective de-icing chemicals. METHODS : First, the recommended amount of de-icing chemical to use and historical usage data were evaluated to identify specific usage characteristics for each region. Road maintenance length and snow-removal working days were analyzed over the past five winter seasons. Next, differences in the recommended amount of chemical to use and actual use were compared using the Kolmogorov-Smirnov test. Last, the two types of data were analyzed using a chi-square test to verify if the two distributions of variation pattern are statistically significant. We found that there are significant differences between the data from each region during the past five winter seasons. RESULTS : The results showed that the equation for calculating the amount of de-icing chemical to use appears to be revised. CONCLUSIONS : The results imply that the equation for calculating the amount of de-icing chemical to apply as a national standard is very important when the public agency makes decisions related to snow-removal.