• 제목/요약/키워드: contingency table

검색결과 118건 처리시간 0.025초

범주형 자료에서 경험적 베이지안 오분류 분석 (Empirical Bayesian Misclassification Analysis on Categorical Data)

  • 임한승;홍종선;서문섭
    • 응용통계연구
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    • 제14권1호
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    • pp.39-57
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    • 2001
  • 범주형 자료에서 오분류는 자료를 수집하는 과정에서 발생될 수 있다. 오분류되어 있는 자료를 정확한 자료로 간주하여 분석한다면 추정결과에 편의가 발생하고 검정력이 약화되는 결과를 초래하게 되며, 정확하게 분류된 자료를 오분류하고 판단한다면 오분류의 수정을 위해 불필요한 비용과 시간을 낭비해야 할 것이다. 따라서 정확하게 분류된 표본인지 오분류된 표본인지를 판정하는 것은 자료를 분석하기 전에 이루어져야할 매우 중요한 과정이다. 본 논문은 I$\times$J 분할표로 주어지는 범주형 자료에서 두 변수 중 하나의 변수에서만 오분류가 발생되는 경우에 오분류 여부를 검정하기 위해서 오분류 가능성이 없는 변수에 대한 주변합은 고정시키고, 오분류 여부를 가능성이 있는 변수의 주변합을 Sebastiani와 Ramoni(1997)가 제안한 Bound와 외부정보로 표현되는 Collapse의 개념, 그리고 베이지안 방법을 확장하여 자료에 적합한 모형과 사전정보를 고려한 사전모수를 다양하게 설정하면서 재분류하는 연구를 하였다. 오분류에 대한 정보를 얻기 위해서 Tenenbein(1970)에 의해 연구된 이중추출법을 이용하여 오분류 검정을 위한 새로운 통계량을 제안하였으며, 제안된 오분류 검정통계량에 관한 분포를 다양한 모의실험을 통하여 연구하였다.

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남해안 돌산도의 해조 II 조하대 해조군락의 구조 (Benthic Marine Algal of Dolsan-Island in the Southern Coast of Korea II Structure of Algal Communities of Subtidal Zone)

  • 손철현;이인규;강제원
    • 한국수산과학회지
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    • 제16권4호
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    • pp.379-388
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    • 1983
  • 본 조사는 전남 여천군 돌산읍 죽포리 두문포의 조하대 해조군락의 특성을 밝히기 위하여 1982년 6월 부터 1983년 5월 까지 연간 계절별로 SCUBA 잠수에 의해 채집된 자료를 분석하므로 수행되었다. 조하대의 수직분포는 sheltered 지역의 특성을 나타내고 있고, 상부, 중부, 하부의 3개 구역으로 나누어지며, 상부는 Ulva pertusa, Codium fragile, Chondria crassicaulis, Gigartina tenera의 녹조, 홍조류, 중부는 Myagropsis myagroides와 Sargassum tortile의 대형갈조류, 하부는 Plocamium telfairiae, Callophyllis japonica, Symphyocladia linearis의 홍조류가 우점종으로 나타났다. Normal association analysis를 통한 군락분석결과 이 지역 해조군락은 9개의 group으로 나누어지고, 각 group의 우점종은 각각 Sargassum tortile, Myagropsis myagroides, Chondrin crassicaulis, Codium fragile, Pterocladia tenuis, Gigartina tenera, Gracilaria textorii등이었고 이 지역의 해중림을 조성하는 대표적 종은 Myagropsis myagroides와 Sargassum tortile 이었다. 한편, Myagropsis myagroides의 현존량은 $50{\times}50cm$당 봄철에 5,248g, 여름에는 650.4g, 가을에는747.6g이었고, 평균체장은 봄부터 가을까지 계절별로 각각 169.9cm, 48,4cm, 149.9cm여서 생식이 끝난 직후인 봄철에 최고치를 나타내고 소멸기인 여름에 최소치를 나타냈다.

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알코올과 마약남용 청소년을 위한 외래치료의 결과에 성별, 부모의 참여정도, 치료종류가 미치는 영향에 대한 연구 (Effect of Gender, Parental Support an Treatment Type on the Adolescent's Successful Completion of Substance Abuse Outpatient Treatment Program)

  • 고윤순
    • 한국사회복지학회:학술대회논문집
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    • 한국사회복지학회 2004년도 추계공동학술대회 자료집
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    • pp.461-492
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    • 2004
  • This study examined the effects of gender, parental support and treatment type on the treatment outcome of adolescent substance abusers. Outcome variable was the successful graduation (or drop) from an Intensive Adolescent Outpatient Program. Adolescents with their parents' support were treated in one of three treatment models (2-weeks Inpatient plus 6 week Intensive Croup-Oriented Outpatient, 8-weeks Intensive Croup-Oriented Outpatient, and 8-weeks Individual-Family Therapy) within a private hospital-affiliated treatment center by managed care practice allowing their own choice (non-random natural assignments). Several hypotheses were tested for main effects by the Log-Linear Analyses for a multi-dimensional contingency table with 440 adolescents (284 boys and 156 girls treated during 1992-l997) from middle-class families with private health insurances. The following results were found. Odds of graduating versus dropping out of the treatment program among : (1) girls were 1.7 times higher than those among boys; (2) adolescents with two-parent were 2.2 times higher than those among adolescents with one-parent ; (3) adolescents with Inpatient plus Outpatient was 1.7 times higher than that of those with Outpatient; (4) adolescents with Individual-Family Therapy was 2.3 times higher than that of those with Outpatient Model. There was no statistically significant outcome difference between the Individual-Family Therapy and the Inpatient plus Outpatient. Implications from the results were discussed. Suggestions were made to improve the treatment components in the areas of gender sensitivity, securing more parental support, alternatives for separation from peer group and integrating new peer groups, and flexibility for the unique needs of individual family. Also, some research questions for future studies were suggested.

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복부 자상 환자에서 즉각적 개복술을 위한 적응증 (Indications for an Immediate Laparotomy in Patients with Abdominal Stab Wounds)

  • 김형주;황성연;최영철
    • Journal of Trauma and Injury
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    • 제20권2호
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    • pp.106-114
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    • 2007
  • Purpose: There is little controversy that a classic indication such as hemodynamic instability or any sign of peritoneal irritation requires an immediate laparotomy in the management of abdominal stab wounds. However, omental herniation or bowel evisceration as an indication for an immediate laparotomy is controversial. The purpose of this study was to evaluate the significance of these factors as indications for an immediate laparotomy. Methods: The medical records of 98 consecutive abdominal stab wounds patients admitted to the Emergency Center of Masan Samsung Hospital from January 2000 to December 2006 were carefully examined retrospectively. Using multivariate logistic regression analysis, thirty-nine factors, including the classic indication and intraabdominal organ evisceration, were evaluated and were found to be associated with a need for a laparotomy. Also, the classic indication was compared with a new indication consisting of components of the classic indication and intra-abdominal organ evisceration by constructing a contingency table according to the need for a laparotomy. Results: Multivariate logistic regression analysis revealed any sign of peritoneal irritation, base deficit, and age to be significant factors associated with the need for a laparotomy (p<0.05). The sensitivity, specificity, and accuracy rates of the classic indication were 98.6%, 72.0%, and 91.8%, respectively, and those of the new indication were 93.2%, 84.0%, and 90.8%, respectively. The differences in those rates between the above two indications were not significant. Conclusion: Intra-abdominal organ evisceration was not a significant factor for an immediate laparotomy. Moreover, the new indication including intra-abdominal organ evisceration was not superior to the classic indication. Therefore, in the management of abdominal stab wounds, the authors suggest that an immediate laparotomy should be performed on patients with hemodynamic instability or with any sign of peritoneal irritation.

PREDICTION OF DAILY MAXIMUM X-RAY FLUX USING MULTILINEAR REGRESSION AND AUTOREGRESSIVE TIME-SERIES METHODS

  • Lee, J.Y.;Moon, Y.J.;Kim, K.S.;Park, Y.D.;Fletcher, A.B.
    • 천문학회지
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    • 제40권4호
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    • pp.99-106
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    • 2007
  • Statistical analyses were performed to investigate the relative success and accuracy of daily maximum X-ray flux (MXF) predictions, using both multilinear regression and autoregressive time-series prediction methods. As input data for this work, we used 14 solar activity parameters recorded over the prior 2 year period (1989-1990) during the solar maximum of cycle 22. We applied the multilinear regression method to the following three groups: all 14 variables (G1), the 2 so-called 'cause' variables (sunspot complexity and sunspot group area) showing the highest correlations with MXF (G2), and the 2 'effect' variables (previous day MXF and the number of flares stronger than C4 class) showing the highest correlations with MXF (G3). For the advanced three days forecast, we applied the autoregressive timeseries method to the MXF data (GT). We compared the statistical results of these groups for 1991 data, using several statistical measures obtained from a $2{\times}2$ contingency table for forecasted versus observed events. As a result, we found that the statistical results of G1 and G3 are nearly the same each other and the 'effect' variables (G3) are more reliable predictors than the 'cause' variables. It is also found that while the statistical results of GT are a little worse than those of G1 for relatively weak flares, they are comparable to each other for strong flares. In general, all statistical measures show good predictions from all groups, provided that the flares are weaker than about M5 class; stronger flares rapidly become difficult to predict well, which is probably due to statistical inaccuracies arising from their rarity. Our statistical results of all flares except for the X-class flares were confirmed by Yates' $X^2$ statistical significance tests, at the 99% confidence level. Based on our model testing, we recommend a practical strategy for solar X-ray flare predictions.

An Australian Retrospective Study to Evaluate the Prognostic Role of p53 and eIF4E Cancer Markers in Patients with Head and Neck Squamous Cell Carcinoma (HNSCC): Study Protocol

  • Singh, Jagtar;Jayaraj, Rama;Baxi, Siddhartha;Mileva, Mariana;Curtin, Justin;Thomas, Mahiban
    • Asian Pacific Journal of Cancer Prevention
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    • 제14권8호
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    • pp.4717-4721
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    • 2013
  • Complete surgical resection of the primary tumour is a crucial predictive step for head and neck squamous cell carcinoma (HNSCC), because incomplete resection may lead to increase in the recurrence rate. Molecular cancer markers have been investigated as potential predictors of prognosis marker, to identify patients who are at high risk of local recurrence. This retrospective study aimed to determine the prognostic correlation between p53 and eIF4E expression and clinical characteristics, recurrence and overall survival. Forty eight HNSCC patients were selected between 2006 and 2009 diagnosed at the Royal Darwin Hospital, Darwin, Northern Territory, Australia. Out of 48, only those 24 with negative surgical margins with hematoxylin and eosin (HandE) were chosedn for further analysis. A total of 77 surgical margins were obtained and subsequently analysed by immunohistochemical (IHC) staining with monoclonal p53 and polyclonal eIF4E antibodies. Contingency table and ${\chi}^2$-test were used to investigate the correlation between p53 and eIF4E expression and clinical characteristics, recurrence and overall survival of the HNSCC patients. The follow up period was 74 months (range 1-74 months). The Kaplan-Meier method was used to generate recurrence and survival curves. This is a first retrospective study of Northern Territory patients, including Indigenous and non-Indigenous Australians. Molecular study of surgical margins could help to identify patients with and without clear margins after surgery and help in choice of the most appropriate adjuvant treatment for HNSCC patients.

일배체형에 기초한 연쇄분석의 통계학적 알고리즘 연구 (Statistical Algorithm in Genetic Linkage Based on Haplotypes)

  • 김진흠;강대룡;이윤경;신선미;서일;남정모
    • Journal of Preventive Medicine and Public Health
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    • 제37권4호
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    • pp.366-372
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    • 2004
  • Objectives : This study was conducted to propose a new transmission/disequilibrium test(TDT) to test the linkage between genetic markers and disease-susceptibility genes based on haplotypes. Simulation studies were performed to compare the proposed method with that of Zhao et al. in terms of type I error probability and powers. Methods : We estimated the haplotype frequencies using the expectation-maximization(EM) algorithm with parents genotypes taken from a trio dataset, and then constructed a two-way contingency table containing estimated frequencies to all possible pairs of parents haplotypes. We proposed a score test based on differences between column marginals and their corresponding row marginals. The test also involved a covariance structure of marginal differences and their variances. In simulation, we considered a coalescent model with three genetic markers of biallele to investigate the performance of the proposed test under six different configurations. Results : The haplotype-based TDT statistics, our test and Zhao et al.'s test satisfied a type I error probability, but the TDT test based on single locus showed a conservative trend. As expected, the tests based on haplotypes also had better powers than those based on single locus. Our test and that of Zhao et al. were comparable in powers. Conclusion : We proposed a TDT statistic based on haplotypes and showed through simulations that our test was more powerful than the single locus-based test. We will extend our method to multiplex data with affected and/or unaffected sibling(s) or simplex data having only one parent s genotype.

Application of Numerical Weather Prediction Data to Estimate Infection Risk of Bacterial Grain Rot of Rice in Korea

  • Kim, Hyo-suk;Do, Ki Seok;Park, Joo Hyeon;Kang, Wee Soo;Lee, Yong Hwan;Park, Eun Woo
    • The Plant Pathology Journal
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    • 제36권1호
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    • pp.54-66
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    • 2020
  • This study was conducted to evaluate usefulness of numerical weather prediction data generated by the Unified Model (UM) for plant disease forecast. Using the UM06- and UM18-predicted weather data, which were released at 0600 and 1800 Universal Time Coordinated (UTC), respectively, by the Korea Meteorological Administration (KMA), disease forecast on bacterial grain rot (BGR) of rice was examined as compared with the model output based on the automated weather stations (AWS)-observed weather data. We analyzed performance of BGRcast based on the UM-predicted and the AWS-observed daily minimum temperature and average relative humidity in 2014 and 2015 from 29 locations representing major rice growing areas in Korea using regression analysis and two-way contingency table analysis. Temporal changes in weather conduciveness at two locations in 2014 were also analyzed with regard to daily weather conduciveness (Ci) and the 20-day and 7-day moving averages of Ci for the inoculum build-up phase (Cinc) prior to the panicle emergence of rice plants and the infection phase (Cinf) during the heading stage of rice plants, respectively. Based on Cinc and Cinf, we were able to obtain the same disease warnings at all locations regardless of the sources of weather data. In conclusion, the numerical weather prediction data from KMA could be reliable to apply as input data for plant disease forecast models. Weather prediction data would facilitate applications of weather-driven disease models for better disease management. Crop growers would have better options for disease control including both protective and curative measures when weather prediction data are used for disease warning.

시추공 영상자료와 카이제곱 검정을 이용한 절리 방향성의 수직적 변화양상에 관한 정량적 평가 (Pearson-type Chi-square Test on the Joint Orientations from Different Depths in Boreholes)

  • 김기석;박영도;박연준
    • 터널과지하공간
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    • 제18권3호
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    • pp.185-193
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    • 2008
  • 이 연구에서는 시추공 분석 작업을 통해 획득된 암반절리 방향성이 심도에 따라 변화하는 양상의 확인을 위해 피어슨 카이제곱 통계검정이 실시되었다. 대상 암반은 모암이 화강암질 편마암인 두 지역으로서, 이와같은 엽리가 발달하지 않은 괴상의 암상 선정은, 엽리가 존재하는 암석의 경우 절리 방향성이 엽리에 의해 영향을 받고 엽리의 방향은 습속 등의 지질작용에 의해 심도에 따라 다를 수가 있기 때문이다. 암반 절리들의 방향 파악을 위해 시추공 영상이 이용되었다. 획득된 방향자료를 천부구간과 심부구간의 자료로 분류한 후 21 영역으로 구성된 분할망에 각각 투영 후, 분류표를 작성하여 통계검정을 실시하였으며, 분석결과 두 지역 중 한 지역의 자료는 비동질로 나타났다. 이러한 결과는 터널과 같은 지하구조물의 설계를 위한 암반공학적으로 중요한 절리면의 방향성에 대한 조사시 원위치 조사가 바람직함을 시사한다.

자전거 교통사고의 통계분석 및 활용 (Statistical analysis and its application of bicycle accidents)

  • 홍종선;김명진
    • Journal of the Korean Data and Information Science Society
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    • 제21권6호
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    • pp.1081-1090
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    • 2010
  • 전세계뿐만 아니라 대한민국 정부에서도 저탄소 녹색성장을 실현하기 위해 노력하고 있으며, 그 방안의 하나로 자전거 수송분담율을 높이기 위하여 자전거도로와 자전거 편의시설 등을 확충하고 있다. 이러한 이유로 자전거 이용자들이 많이 증가하고 있는데 반면에 자전거 교통사고도 급증하는 추세이다. 자전거 교통사고 자료는 경찰청에서 발간하는 연감자료가 유일하나, 이 자료는 사고의 빈도수를 이차원 분할표 형태로 제공하고 있기때문에 일반인들이 이 자료를 통하여 사고의 성격과 위험율에 대하여 파악하고 이해하기 어렵다. 따라서 본 연구에서는 자전거사고 자료를 확률로 표현하고 자전거 인구와 자동차 등록대수 자료와 결합하여 자전거사고의 특징을 분석하고 파악한다. 또한 조건부 독립이라는 가정 하에 현실세계의 현상에서 자전거사고 발생확률을 구하는 방법을 제안하고, 이 방법을 활용하여 자전거사고를 줄일 수 있는 방안에 대해 논의한다.