• Title/Summary/Keyword: Non-Parametric Statistics

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Robust determination of control parameters in K chart with respect to data structures (데이터 구조에 강건한 K 관리도의 관리 모수 결정)

  • Park, Ingkeun;Lee, Sungim
    • Journal of the Korean Data and Information Science Society
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    • v.26 no.6
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    • pp.1353-1366
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    • 2015
  • These days Shewhart control chart for evaluating stability of the process is widely used in various field. But it must follow strict assumption of distribution. In real-life problems, this assumption is often violated when many quality characteristics follow non-normal distribution. Moreover, it is more serious in multivariate quality characteristics. To overcome this problem, many researchers have studied the non-parametric control charts. Recently, SVDD (Support Vector Data Description) control chart based on RBF (Radial Basis Function) Kernel, which is called K-chart, determines description of data region on in-control process and is used in various field. But it is important to select kernel parameter or etc. in order to apply the K-chart and they must be predetermined. For this, many researchers use grid search for optimizing parameters. But it has some problems such as selecting search range, calculating cost and time, etc. In this paper, we research the efficiency of selecting parameter regions as data structure vary via simulation study and propose a new method for determining parameters so that it can be easily used and discuss a robust choice of parameters for various data structures. In addition, we apply it on the real example and evaluate its performance.

The consideration for methods of statistical analysis about the thesis published in the journal of korean oriental medical Ophthalmology & Otolaryngology & Dermatology from 2003 to 2005 (2003년부터 2005년까지 안이비인후피부과 학회지에 게재된 논문들의 통계적 분석 방법에 대한 고찰)

  • Kim, Keoo-Seok;Nam, Hae-Jung;Park, Owe-Suk;Kim, Hee-Jeong;Cha, Jae-Hoon;Kim, Yoon-Bum
    • The Journal of Korean Medicine Ophthalmology and Otolaryngology and Dermatology
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    • v.19 no.3 s.31
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    • pp.134-145
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    • 2006
  • Objective : This study was carried out to investigate what type of assumption and conditions are needed for the application of various statistical techniques such as descriptive statistics, t-test, analysis of variance, correlation analysis, regression analysis and chi-square test and to evaluate that they are used correctly in the research process. Methods : One more methods of statistical analysis were used in 91 papers among 162 papers selected from the journal of Korean oriental medical Ophthalmology & Otolaryngology & Dermatology from April 2003 to December 2005. So we analysed the type of statistical analysis method in 91 papers(clinical and experimental study) and assessed the their validity of statistical techniques by the check list consisting of 34 items(3 items for validity assessment of descriptive statistics, 6 items for t-test, 7 items for analysis of variance, correlation analysis and regression analysis, respectively, 4 items for chi-square test) Results : 1. The type of 65(40%) cases is experimental trial, the type of 55(34%) cases is case report, the type of 26(16%) cases is clinical trial and the type of 16(10%) cases is review, in 91 papers using statistical techniques among 162 papers selected from the journal of Korean oriental medical Ophthalmology & Otolaryngology & Dermatol-ogy from April 2003 to December 2005. 2. One more methods of statistical analysis were used in the experimental and clinical study. When we classified 125 units using statistical analysis methods in 91 papers according to statistical techniques such as descriptive statistics, t-test, analysis of variance, correlation analysis, regression analysis and chi-square test, the number of independent sample t-test is 33(26%), the number of only descriptive statistics is 28(22%), the number of independent sample t-test is 33(26%), the number of only descriptive statistics is 28(22%), the number of one way ANOVA is 15(12%), the number of non-parametric test 10(8%). 3. After carrying out one way ANOVA, the number of using multiple comparison methods is 15(Scheffe:6(26%), Duncan:4(17%), Dunnett:3(13%), Tukey:2(9%)) out of 23 (total case carrying out one way ANOVA). 8(35%) out of 23 did not enforce multiple comparison methods after carrying out one way ANOVA. 4. From the assessment of validity about 63 cases using statistical techniques(except descriptive statistics), 5(8%) cases are proper, the other 58(92%) are improper, so we recognized a serious misuse of statistical application in our journal. 5. The number of case below 10 sample size in experimental and clinical study(except descriptive statistics) is 31(34%) and frequent. Also the number of case containing no mention of sample size is 41(45%, including culture study). 6. For example of statistical error, there are wrong choice of statistical technique, lack of check on standard assumption(such as standard distribution, equivariance, independence), and so on. Conclusions : We investigated the validity of statistical analysis methods in our journal by check list consisting of 34 items and suggested correct statistical analysis methods. We should practice the spread of education about statistical analysis methods and precis application, enhance objectivity and reliability of our thesis and further correspond with purpose of scientific study.

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The methodology for developing the 2007 Korean growth charts and blood pressure nomogram in Korean children and adolescents (2007 한국 소아청소년 성장곡선 및 정상혈압 분포 개발 방법론)

  • Lee, Soon Young;Kim, Youn Nam;Kang, Yeon Ji;Jang, Myoung-Jin;Kim, Jinheum;Moon, Jin Soo;Lee, Chong Guk;Oh, Kyungwon;Kim, Young Taek;Nam, Chung Mo
    • Clinical and Experimental Pediatrics
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    • v.51 no.1
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    • pp.26-32
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    • 2008
  • Purpose : This study was to provide the methods of developing the growth charts and the blood pressure nomogram among Korean children and adolescents. Methods : The growth charts were developed based on the data from the national growth surveys for children and adolescents in 1998 and 2005. The percentile charts were developed through two stages. At the first stage, the selected empirical charts were smoothed through several fitting procedures including parametric and non-parametric methods. At the second stage, a modified LMS (lambda, mu, sigma) statistical procedure was applied to the smoothed percentile charts. The LMS procedure allowed to estimate any percentile and to calculate standard deviation units and z-scores. The charts for weight-for-age, height-for-age, BMI-for-age, weight-for-height and head circumference-for-age were developed by sex. Age and normalized height controlled sex-specific nomograms of systolic and diastolic blood pressure were developed by a fixed effect model of general regression using the data from 2005 national growth survey. Results : The significant systemic differences between the percentiles of growth charts and the empirical data were not found. The final output of the study is available from Korean Center for Disease Control and Prevention homepage, http://www.cdc.go.kr/webcdc/. Blood Pressure nomogram was tabulated by height percentiles and age using the regression coefficients analyzed with regression model. Conclusion : 2007 growth charts and blood pressure nomogram were the first products based on the statistical modeling using the national survey data. The further study on the methodology including data collection, data cleaning and statistical modeling for representative growth charts would be needed.

A Road Extraction Algorithm using Mean-Shift Segmentation and Connected-Component (평균이동분할과 연결요소를 이용한 도로추출 알고리즘)

  • Lee, Tae-Hee;Hwang, Bo-Hyun;Yun, Jong-Ho;Park, Byoung-Soo;Choi, Myung-Ryul
    • Journal of Digital Convergence
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    • v.12 no.1
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    • pp.359-364
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    • 2014
  • In this paper, we propose a method for extracting a road area by using the mean-shift method and connected-component method. Mean-shift method is very effective to divide the color image by the method of non-parametric statistics to find the center mode. Generally, the feature points of road are extracted by using the information located in the middle and bottom of the road image. And it is possible to extract a road region by using this feature-point and the partitioned color image. However, if a road region is extracted with only the color information and the position information of a road image, it is possible to detect not only noise but also off-road regions. This paper proposes the method to determine the road region by eliminating the noise with the closing / opening operation of the morphology, and by extracting only the portion of the largest area using a connected-components method. The proposed method is simulated and verified by applying the captured road images.

A Study on Job Stress and Work Ability of Technical Workers and Simple Labor Workers in Apartment Construction (아파트공사 기능직 종사자와 단순노무 근로자의 직무스트레스와 작업능력에 관한 연구)

  • Lee, Jong-Bin;Chang, Seong Rok
    • Journal of the Korean Society of Safety
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    • v.29 no.5
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    • pp.129-135
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    • 2014
  • In recent studies, construction industry workers with higher job stress and lower work ability were more likely to experience accidents at their workplace. Likewise, fatal accidents rate was higher among simple labor workers compared to technical workers. Therefore the evaluation of a worker's job stress and work ability seems to be important in preventing the occurrence of fatal accidents. To search for ways to reduce job stress and to improve work ability, the current study conducted a job stress analysis based on age, years of service, skill level, hobbies, sleep patterns, and monthly income. For this, the Korean occupational stress questionnaire short form and the Work Ability Index (WAI) developed by the Finnish Institute of Occupational Health (FIOH) were used. In this study, SPSS 12.0K statistics program was used for statistical analysis and significance was verified by the Kruskal-Wallis test and non-parametric tests. The results of this study can be summarized as follows : (1) Simple labor workers had higher job stress and less work ability than technical workers. (2) The more experienced workers had lower job stress and higher work ability. (3) In the case of workers who slept a lot, work ability was higher and job stress was less. (4) Monthly income influenced on the job stress and work ability. (5) Job stress and work ability in accordance with the age difference was not significant.

A Study on the Nurses' Thinking Skills and Problem Solving Abilities for Quality Management in Healthcare Services (질 관리에 대한 간호사의 사고유형과 문제해결력)

  • Ko, Ja Kyung;Park, Yon Ok
    • Quality Improvement in Health Care
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    • v.5 no.2
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    • pp.238-256
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    • 1998
  • Background : There have been many studies and efforts about quality management in health services, but these were not focused on the thinking ability of the personnel. In this study, We planned to define the relationship between Quality Management(QM) and thinking skill, and analyzed critical thinking skill and problem solving ability of the nurses for QM in healthcare. Methods : We surveyed 260 nurses in 3 hospitals by using questionnaires about thinking skills and QM from November 18 to 28, 1998. The response rate was 76.9%. We described and analyzed the data by descriptive statistics, t-test, ANOVA, Pearson correlation, and non-parametric Friedman test using SPSS Win 7.5. Results : This study revealed that 1) understanding level of QM concepts was very low and insufficient, 2) willingness to practice QM in healthcare was relatively high and affirmative, but the positive attitude taking part in the program of QM is very low(4.5%), 3) even though the necessity of QM was recognized, actual application of critical thinking skills and problem solving abilities is lacking, 4) the production of idea for QM was the most insufficient, and so the next of the problem solving process(QA cycle) was the same. Conclusion : Based on the above results, we can conclude that understanding the concepts of QM is very important to solve problems about QM in healthcare. For development of thinking skill to promote critical problem solving ability for QM in healthcare, it is necessary to improve curriculum of nursing education and teaching-learning methods of QM strategy and technique.

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Preferences of Malaysian Cancer Patients in Communication of Bad News

  • Eng, Tan Chai;Yaakup, Hayati;Shah, Shamsul Azhar;Jaffar, Aida;Omar, Khairani
    • Asian Pacific Journal of Cancer Prevention
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    • v.13 no.6
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    • pp.2749-2752
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    • 2012
  • Background: Breaking bad news to cancer patients is a delicate and challenging task for most doctors. Better understanding of patients' preferences in breaking bad news can guide doctors in performing this task. Objectives: This study aimed to describe the preferences of Malaysian cancer patients regarding the communication of bad news. Methodology: This was a cross-sectional study conducted in the Oncology clinic of a tertiary teaching hospital. Two hundred adult cancer patients were recruited via purposive quota sampling. They were required to complete the Malay language version of the Measure of Patients' Preferences (MPP-BM) with minimal researcher assistance. Their responses were analysed using descriptive statistics. Association between demographic characteristics and domain scores were tested using non-parametric statistical tests. Results: Nine items were rated by the patients as essential: "Doctor is honest about the severity of my condition", "Doctor describing my treatment options in detail", "Doctor telling me best treatment options", Doctor letting me know all of the different treatment options", "Doctor being up to date on research on my type of cancer", "Doctor telling me news directly", "Being given detailed info about results of medical tests", "Being told in person", and "Having doctor offer hope about my condition". All these items had median scores of 5/5 (IQR:4-5). The median scores for the three domains were: "Content and Facilitation" 74/85, "Emotional Support" 23/30 and "Structural and Informational Support" 31/40. Ethnicity was found to be significantly associated with scores for "Content and Facilitation" and "Emotional Support". Educational status was significantly associated with scores for "Structural and Informational Support". Conclusion: Malaysian cancer patients appreciate the ability of the doctor to provide adequate information using good communication skills during the process of breaking bad news. Provision of emotional support, structural support and informational support were also highly appreciated.

In vitro study of fracture strength of provisional crown materials

  • Karaokutan, Isil;Sayin, Gulsum;Kara, Ozlem
    • The Journal of Advanced Prosthodontics
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    • v.7 no.1
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    • pp.27-31
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    • 2015
  • PURPOSE. The purpose of this report was to evaluate the effect of the fabrication method and material type on the fracture strength of provisional crowns. MATERIALS AND METHODS. A master model with one crown (maxillary left second premolar) was manufactured from Cr-Co alloy. The master model was scanned, and the data set was transferred to a CAD/CAM unit (Yenamak D50, Yenadent Ltd, Istanbul, Turkey) for the Cercon Base group. For the other groups, temporary crowns were produced by direct fabrication methods (Imident, Temdent, Structur Premium, Takilon, Systemp c&b II, and Acrytemp). The specimens were subjected to water storage at $37^{\circ}C$ for 24 hours, and then they were thermocycled (TC, $5000{\times}$, $5-55^{\circ}C$) (n=10). The maximum force at fracture (Fmax) was measured in a universal test machine at 1 mm/min. Data was analyzed by non-parametric statistics (${\alpha}$=.05). RESULTS. Fmax values varied between 711.09-1392.1 N. In the PMMA groups, Takilon showed the lowest values (711.09 N), and Cercon Base showed the highest values (959.59 N). In the composite groups, Structur Premium showed the highest values (1392.1 N), and Acrytemp showed the lowest values (910.05 N). The composite groups showed significantly higher values than the PMMA groups (P=.01). CONCLUSION. Composite-based materials showed significantly higher fracture strengths than PMMA-based materials. The CADCAM technique offers more advantages than the direct technique.

A Study on the Correlation between Iris Markings and Obesity Indices (홍채표지와 비만지표와의 상관성 연구)

  • Lim, Young-Woo;Park, Seung-Il;Park, Young-Jae;Park, Young-Bae
    • The Journal of the Society of Korean Medicine Diagnostics
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    • v.17 no.2
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    • pp.112-121
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    • 2013
  • Objectives This study analyze the correlation between iris markings and the obesity level shown in body composition indices. And It quantitatively evaluates iris markings according to the level of obesity to improve a clinical application plan for the iris analysis. Methods This study analyzed the iris and body composition through the quantization of iris markings for 28 female patients. It calculated descriptive statistics by using SPSS 13.0 and investigated correlation coefficients of non-parametric Spearman in order to analyze the relation between iris markings and body composition indices. Results Considering the correlation between iris markings and body composition indices, an area of the pupil had a significant positive correlation with height and with fat-free amount such as body water, protein, and minerals. BMI showed significant positive correlations with the length of the autonomic nerve wreath and the ratio of the autonomic nerve wreath, and the area of the autonomic nerve wreath. Moreover, the number of lacunas in the pancrea area had a significant positive correlation with weight and BMI. Conclusions This study objectifies the quantification of iris markings to identify the correlation between iris markings and the level of obesity. The study results will be used as a basic data to make standards for the diagnosis of obesity, the treatment of related diseases, and the diagnosis of iris markings for prevention.

A Study on the Intention to Use Community Care Service by Pre-Caregivers Based on Dementia Under the Long-Term Care Insurance System for the Aged -Special dementia rating (5 rates) in the focus (예비치매 부양자의 재가서비스 이용에 관한 연구 -치매특별등급(5등급) 중심으로)

  • Son, Yi-Suk;Lee, Kyung-Soo;Chung, Jae-wook
    • Journal of Korean Clinical Health Science
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    • v.4 no.3
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    • pp.603-614
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    • 2016
  • Purpose. The purpose of this study was to provide basic data regarding the intention to use community care service based on special grading for dementia in the South Korean Society. Methods. A survey was conducted using a questionnaire adapted on the basis of literature review regarding the first to fourth grade under the long-term care insurance system for the aged from May 1 to 30, 2015 and a total of 272 questionnaires were statistically processed using SPSS 21.0. Frequency analysis, descriptive statistics, and cross-tabulation analysis were performed. The non-parametric type of test, ${\chi}^2$ test, was used for statistical testing. Results. This study obtained the following results: First, caregivers had greater intention to ask recipients to use daytime and nighttime care service. Second, there were statistically significant differences in caregivers' education, occupation, monthly average income, co-residence status, intimacy, and care-giving burden (emotional, financial, and social) and recipients' activities of daily living, instrumental activities of daily living, mental health status, dementia status, and intention to use community care service based on special grading for dementia. Conclusions. There are very few statistical data and academic materials regarding special grading for dementia, which has recently been established. The results of this study are therefore expected to help make a systematic analysis of the intention to use community care service by caregivers based on special grading for dementia.