• 제목/요약/키워드: Chi-squared Test

검색결과 287건 처리시간 0.025초

Bayesian test of homogenity in small areas: A discretization approach

  • Kim, Min Sup;Nandram, Balgobin;Kim, Dal Ho
    • Journal of the Korean Data and Information Science Society
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    • 제28권6호
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    • pp.1547-1555
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    • 2017
  • This paper studies Bayesian test of homogeneity in contingency tables made by discretizing a continuous variable. Sometimes when we are considering events of interest in small area setup, we can think of discretization approaches about the continuous variable. If we properly discretize the continuous variable, we can find invisible relationships between areas (groups) and a continuous variable of interest. The proper discretization of the continuous variable can support the alternative hypothesis of the homogeneity test in contingency tables even if the null hypothesis was not rejected through k-sample tests involving one-way ANOVA. In other words, the proportions of variables with a particular level can vary from group to group by the discretization. If we discretize the the continuous variable, it can be treated as an analysis of the contingency table. In this case, the chi-squared test is the most commonly employed method. However, further discretization gives rise to more cells in the table. As a result, the count in the cells becomes smaller and the accuracy of the test becomes lower. To prevent this, we can consider the Bayesian approach and apply it to the setup of the homogeneity test.

혈액원 노동자의 주관적 건강 상태 관련 요인: 긍정심리자본, 직무스트레스를 중심으로 (Associations Between Perceived Health Status and positive psychology capital and job stress Among Korean Red Cross Workers)

  • 김정애;황지원;박민주
    • 산업융합연구
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    • 제18권6호
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    • pp.75-83
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    • 2020
  • 본 연구는 혈액원 노동자들의 건강한 근무환경 개선을 위한 토대를 제공하고자 작성된 서술적 조사연구이다. 설문지는 2020년 9월 8일부터 10월 31일까지 215부가 수집되었다. SPSS 19.0 통계 프로그램으로 카이제곱검정 및 피셔정확검정(Chi-squared test or Fisher's extract test), 독립표본 t-test, 다중로지스틱회귀분석(Mutiple Logistic Regression)을 하였다. 관련 요인 보정 후 긍정심리자본 및 직무스트레스와 주관적 건강 상태와의 관련성을 평가하기 위해 다중로지스틱회귀분석을 시행한 결과, 일반적 특성 및 업무특성과 주관적 건강 상태와는 관련성이 없었으며, 불건강군과 건강군의 긍정심리자본과 직무스트레스는 유의미한 평균 차이를 각각 보였다(p<.001, p<.001). 긍정심리자본이 한 단위 증가할수록 주관적 건강 상태의 양호한 건강군의 오즈비는 1.1배[95% confidence interval (CI): 1.0-1.1] 유의하게 증가 하였고, 직무스트레스가 한 단위 증가할수록 주관적 건강 상태의 양호한 건강군의 오즈비는 0.9배로[95% confidence interval (CI): 0.8-0.9] 유의하게 감소하는 결과를 보였다.

학생 정서·행동특성 검사 및 관리에 대한 학부모의 지식과 태도 (Parents' Knowledge and Attitudes Regarding a Screening Test for and Subsequent Management of Students' Emotional and Behavioral Problems)

  • 김명희;서지민
    • Child Health Nursing Research
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    • 제23권2호
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    • pp.207-218
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    • 2017
  • Purpose: The purpose of this study was to investigate parents' perceptions and attitudes regarding a screening test for and subsequent management of students' emotional and behavioral problems. Methods: A descriptive research design was used, and included disproportional stratified and cluster random sampling. The sample comprised 223 parents of elementary, middle, and high school students. Data were analyzed using descriptive statistics, Chi-squared test, and ANOVA with SPSS/WIN 21.0. Results: Overall, parents responded that they knew of the goals, types, and tools of screening tests for students' emotional and behavioral problems. In total, 64.6% of parents reported having information for the screening test in advance. Only 13.5%(n=30) of students had emotional and behavioral problems in the last year. Among these students, 56.7%(n=17) were referred to mental health facilities but only 29.4%(n=5) of them received ongoing management from these facilities. Conclusion: These findings suggest that parents should receive information about the screening test for and subsequent management of students' emotional and behavioral problems. Health professionals need to build strategies to provide ongoing management for students who have emotional and behavioral problems.

대한민국 사슴농가 종사자의 라임병 혈청유병률 및 위험요인 (Seroprevalence and risk factors of Lyme disease among Korean deer farmers)

  • 딜라람 아지리아;조재학;유석주;박지혁
    • 농촌의학ㆍ지역보건
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    • 제44권2호
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    • pp.82-89
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    • 2019
  • 목적 : 이번 연구는 인수공통감염병의 고위험군인 사슴농가 종사자를 대상으로 라임병의 감염 실태 파악 및 위험요인 분석을 위해 수행하였다. 대상 및 방법 : 전국 시 군 지역의 사슴농가를 중심으로 516명에 대해 설문조사 및 혈청검사를 실시하였다. 라임병 진단방법은 IFA(Indirect Immunofluorescence antibody Assay, 간접면역형광항체법)와 IFA검사의 높은 위양성률을 보완하기 위해 ELISA 검사 그리고 Western Blot 법을 이용하였다. 결과 : 전국 사슴농가 종사자 516명의 라임병 최종 혈청 유병률은 2.3%이었으며, 엘크 (Cervus Canadensis)만을 기르는 사슴 농가 종사자의 라임병 혈청유병률이 3.6%로 다른 종류의 사슴을 키우는 사슴 농가 종사자보다 라임병 발병 위험이 통계적으로 유의하게 높았다(p = 0.033). 결론 : 국내 사슴농가 종사자들이 인수공통감염병인 라임병에 노출되어 있음을 확인하였고, 키우는 사슴의 종류나 작업 행태, 보호복 착용 여부 등에 따라 라임병 노출의 가능성이 다름을 확인할 수 있었다.

사상체질(四象體質)의 유전성(遺傳性) 검토(檢討)에 대한 통계적(統計的) 연구(硏究) (Statistical Study on Heredity in SaSang Constitutional Medicine)

  • 김대윤;이재원;김달래
    • 사상체질의학회지
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    • 제11권1호
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    • pp.159-168
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    • 1999
  • Purpose : Sasang Constitutional Medicine explains the pathology peculiar to constitution and suggests treatment for each constitution. In Sasang Constitutional Medicine hwnan beings are classified on four groups; Taeyangin, Taeumin, 5oyangin, Soeumin. These four constitution has their's own symptoms and treatments. In treatment, control of mind inclination, that is to say, moderation takes a very important role. But the study on heredity in Sasang Constitutional Medicine has not done not biological study but also statistical study. So we used several statistical methods and analyzed 163 samples. Methods : We implemented Fishers exact test for adjusting chi-squared test, kappa coefficient to estimate agreement of parent's and children's constitutions, and finally plotted bi-plot using correspondence analysis. Results : From Fisher's exact test result, we could know that parent's and children'S constitution's distribution had significant difference. In kappa coefficient, mother and daughter's estimated value produced highest result. In correspondence analysis we only plotted the case of mother and son for easy interpretation. Conclusion : In the study of heredity of SaSang constitution, we cannot know exactly the heredity of constitution in terms of biology or genetics. But this research can be helpful for further analysis, that is, a study of biological or genetical aspects. And we could conclude that in statistical aspects the heredity in SaSang constitution is meaningful.

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United Kingdom pediatric dentistry specialist views on the administration of articaine in children

  • Ezzeldin, Maryam;Hanks, Gemma;Collard, Mechelle
    • Journal of Dental Anesthesia and Pain Medicine
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    • 제20권5호
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    • pp.303-312
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    • 2020
  • Background: Lidocaine is the gold standard local anesthetic (LA) for UK pediatric dental treatment. Recent reports suggest frequent Articaine use in Europe and Canada, with evidence indicating more profound anesthesia. The aim of this study was to examine pediatric dentistry specialist experiences and practices relating to Articaine administration in the UK. Methods: A literature review was followed by a survey using an anonymous 15-item electronic questionnaire, which was sent to 200 registered British Society of Pediatric Dentistry (BSPD) specialists. Descriptive analyses, Z score, chi-squared test, Fisher's exact test, and Spearman's correlation test were performed. Results: Sixty-one (30.5%) participants responded, and 12 (19.7%) indicated Articaine as their first line anesthetic. Articaine was used daily or weekly by 38 (62.3%) respondents, depending on the clinical context. Articaine was commonly used to avoid inferior alveolar nerve blocks and gain more profound anesthesia in abscessed or hypomineralized teeth. Participants reported significantly more adverse effects with lidocaine (Fisher's exact test, P < 0.0001) than with Articaine. Articaine was most often administered in children aged > 4 years via infiltration techniques. Only 15 (24.6%) respondents reported awareness of guidelines for Articaine use in pediatric patients. Conclusions: Articaine use in pediatric dentistry is common; however, evidence supporting its practice is limited. Several specialists follow conventions based on anecdotal evidence. Formulating guidance to aid decision-making when treating pediatric patients under LA would be beneficial.

일개 상급종합병원 응급중환자실 내 심정지 후 저체온요법을 적용한 환자의 말초 청색증 발생 현황 (Incidence of Peripheral Cyanosis in Patients with Therapeutic Hypothermia after Cardiac Arrest in the Acute Care Unit of a Tertiary General Hospital)

  • 방수연;이영희
    • 중환자간호학회지
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    • 제14권3호
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    • pp.128-140
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    • 2021
  • Purpose : This study aimed to identify the incidence of peripheral cyanosis and the characteristics and clinical results of patients with therapeutic hypothermia after a cardiac arrest. Methods : Data were collected from April to June 2021 via the electrical medical records of 95 patients with therapeutic hypothermia for 72 hours after a cardiac arrest admitted to an acute care unit at a tertiary hospital between January 1, 2016, and December 31, 2019. The data were analyzed using descriptive statistics and a t-test, Mann-Whitney U test, Chi-squared test, Fisher's exact test, and logistic regression using SPSS/WIN. Results : The incidence of peripheral cyanosis was 20%. In the peripheral cyanosis group, peripheral vascular disease, fibrinogen, vasopressor, infection, disseminated intravascular coagulation, acute physiology, chronic health evaluation II score on the second hospital day, nursing intervention, and mortality on the seventh hospital day were higher. The level of fibrinogen and use of vasopressors affected the occurrence of peripheral cyanosis. Conclusion : Considering the influencing variables, careful observation is necessary for patients with high fibrinogen levels and vasopressor use. These results provide basic data to recognize the need for nursing intervention for peripheral cyanosis and encourage nurses to deliver them during therapeutic hypothermia.

Differences by Selection Method for Exposure Factor Input Distribution for Use in Probabilistic Consumer Exposure Assessment

  • Kang, Sohyun;Kim, Jinho;Lim, Miyoung;Lee, Kiyoung
    • 한국환경보건학회지
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    • 제48권5호
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    • pp.266-271
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    • 2022
  • Background: The selection of distributions of input parameters is an important component in probabilistic exposure assessment. Goodness-of-fit (GOF) methods are used to determine the distribution of exposure factors. However, there are no clear guidelines for choosing an appropriate GOF method. Objectives: The outcomes of probabilistic consumer exposure assessment were compared by using five different GOF methods for the selection of input distributions: chi-squared test, Kolmogorov-Smirnov test (K-S), Anderson-Darling test (A-D), Akaike information criterion (AIC) and Bayesian information criterion (BIC). Methods: Individual exposures were estimated based on product usage factor combinations from 10,000 respondents. The distribution of individual exposure was considered as the true value of population exposures. Results: Among the five GOF methods, probabilistic exposure distributions using the A-D and K-S methods were similar to individual exposure estimations. Comparing the 95th percentiles of the probabilistic distributions and the individual estimations for 10 CPs, there were 0.73 to 1.92 times differences for the A-D method, and 0.73 to 1.60 times differences (excluding tire-shine spray) for the K-S method. Conclusions: There were significant differences in exposure assessment results among the selection of the GOF methods. Therefore, the GOF methods for probabilistic consumer exposure assessment should be carefully selected.

소표본에서 차이측도 통계량의 비교연구 (A Monte Carlo Comparison of the Small Sample Behavior of Disparity Measures)

  • 홍종선;정동빈;박용석
    • 응용통계연구
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    • 제16권2호
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    • pp.455-467
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    • 2003
  • 소표본 분할표 자료에서 적합도 검정통계량들의 카이제곱 근사 적용 가능에 대하여 많은 연구가 진행되었다. 소표본에서 세 가지 검정 통계량(피어슨 카이제곱 Χ$^2$, 일반화 가능도비 G$^2$, 그리고 역발산 Ι(2/3) 검정통계량)에 관하여 비교한 Rudas(1986)의 연구를 확장하여, 최근에 제안된 차이측도(BWHD(1/9), BWCS(1/3), NED(4/3) 검정통계량)를 포함시켜 비교 분석하였다. 독립모형의 이차원 분할표, 조건부 독립모형과 한 변수 독립 모형을 따르는 삼차원 분할표에 대한 모의실험을 통하여 생성된 90과 95 백분위수와 이에 대응하는 95% 신뢰구간을 살펴보고 실제 백분위수와 비교하였다. 그 결과 Χ$^2$, Ι(2/3), 그리고 BWHD(1/9) 검정통계량이 유사한 결과를 나타내었고 이 통계량들이 기존에 제안된 검정통계량들보다 적은 표본크기에서도 카이제곱 근사방법에 적용 가능함을 발견하였다.

Comparing Feature Selection Methods in Spam Mail Filtering

  • Kim, Jong-Wan;Kang, Sin-Jae
    • 한국정보기술응용학회:학술대회논문집
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    • 한국정보기술응용학회 2005년도 6th 2005 International Conference on Computers, Communications and System
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    • pp.17-20
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    • 2005
  • In this work, we compared several feature selection methods in the field of spam mail filtering. The proposed fuzzy inference method outperforms information gain and chi squared test methods as a feature selection method in terms of error rate. In the case of junk mails, since the mail body has little text information, it provides insufficient hints to distinguish spam mails from legitimate ones. To address this problem, we follow hyperlinks contained in the email body, fetch contents of a remote web page, and extract hints from both original email body and fetched web pages. A two-phase approach is applied to filter spam mails in which definite hint is used first, and then less definite textual information is used. In our experiment, the proposed two-phase method achieved an improvement of recall by 32.4% on the average over the $1^{st}$ phase or the $2^{nd}$ phase only works.

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