• Title/Summary/Keyword: statistical confidence

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A Study on Relationship to Risk Factors according to Menopausal Status in Breast Cancer (유방암 환자에 있어서 폐경상태에 따른 위험인자의 상관성 연구)

  • Yoon, Han-Sik
    • Journal of radiological science and technology
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    • v.23 no.1
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    • pp.49-54
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    • 2000
  • It is important to identify modifiable risk factors for breast cancer, because the breast cancer is one of the major causs of mortality among women. Some reported that obesity is a risk factor for breast cancer, but the results are not constant. Many risk factors are related to the duration of estrogenic stimulation of the breast. In general, early menarche and late menopause are positive risk factors. Human breast cancer has different characteristics according to the status of menopause(premenopause and postmenopause). In premenopausal women, about 60% of circulating estrogen is from the ovaries in the form of estradiol, and the remaining 40% is estrogen formed primarily in the adipose(fat) tissue via aromatization of androstenedion from the adrenal glands. After menopause this adipose cell production of estrone is the main source of estrogens and the level of estrone is maintained approximately at premenopausal levels. This study was undertaken to determine the role of body size and body mass index by status of menopause in development of breast cancer using retrospective case/control study. From March 1991 to February 1997 at the Wonkwang University Hospital, the breast cancer cases(n=72) and controls(n=86) were selected. By statistical analysis method, regression analysis, paired T-test and multiple logistic regression were done to estimate the influenced factors same as height, weight, BMI, age at menarche and age at menopause. The following results were obtained : 1. In premenopausal women, age at menarche was showed comparatively high correlation coefficients and BMI was described prominently highly in postmenopause. 2. At the results of multiple regression analysis, age at monarch, BMI and weight were showed as significant variables. In this method, critical factor ($R^2$) was 0.054. 3. Paired samples T-test was undertaken to test mean difference between two groups of cases and controls. The result of test performance showed a significant difference. 4. In comparison with women whose weight less than 50 kg, the ORs for the upper 5th group was 1.82(95% confidence interval). The heaviest women had a higher risk(OR=1.14, 95% confidence interval $1.12{\sim}1.31$, p=0.005). Higher body mass index was significantly associated with increased risk of premenopausal breast cancer (OR=1.01, 95% confidence interval $1.08{\sim}l.18$, p=0.05).

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Impact of Ensemble Member Size on Confidence-based Selection in Bankruptcy Prediction (부도예측을 위한 확신 기반의 선택 접근법에서 앙상블 멤버 사이즈의 영향에 관한 연구)

  • Kim, Na-Ra;Shin, Kyung-Shik;Ahn, Hyunchul
    • Journal of Intelligence and Information Systems
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    • v.19 no.2
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    • pp.55-71
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    • 2013
  • The prediction model is the main factor affecting the performance of a knowledge-based system for bankruptcy prediction. Earlier studies on prediction modeling have focused on the building of a single best model using statistical and artificial intelligence techniques. However, since the mid-1980s, integration of multiple techniques (hybrid techniques) and, by extension, combinations of the outputs of several models (ensemble techniques) have, according to the experimental results, generally outperformed individual models. An ensemble is a technique that constructs a set of multiple models, combines their outputs, and produces one final prediction. The way in which the outputs of ensemble members are combined is one of the important issues affecting prediction accuracy. A variety of combination schemes have been proposed in order to improve prediction performance in ensembles. Each combination scheme has advantages and limitations, and can be influenced by domain and circumstance. Accordingly, decisions on the most appropriate combination scheme in a given domain and contingency are very difficult. This paper proposes a confidence-based selection approach as part of an ensemble bankruptcy-prediction scheme that can measure unified confidence, even if ensemble members produce different types of continuous-valued outputs. The present experimental results show that when varying the number of models to combine, according to the creation type of ensemble members, the proposed combination method offers the best performance in the ensemble having the largest number of models, even when compared with the methods most often employed in bankruptcy prediction.

The study of Needs and Demands for First Aid Education of School Health Educator (보건교사의 응급처치 교육 필요도 및 교육 요구도에 관한 연구)

  • Choi, Uk-Jin;Cho, Keun-Ja
    • The Korean Journal of Emergency Medical Services
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    • v.12 no.1
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    • pp.27-41
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    • 2008
  • Purpose : With increasing number of school accidents, it is crucial to find out necessity of first aid training among school health educator. This study has been conducted to have an clear idea on the demands and necessity for first aid training and what kind of training is most required from school health educator. Method : In this study, questionnaires from 87 school health educator in elementary, middle and high school health educator in the city D were analyzed. The survey was carned out from May 26, 2008 to June 7, 2008 and from the collected data, frequency, independent two samples t-test, paired T-test, one way ANOVA and pearson's correlation were conducted with SPSS 14.0. Result: 1. 51.61 % of nurse-teachers experienced emergency situations and the relations between the necessity they felt from experiencing those situations and demands for first aid training were not statistically meaningful(t=1.87, p= .175). 2. Necessity and demands for the first-aid training were checked with three point scale and there were statistical significance between the two with $2.44{\pm}.47$ and $2.24{\pm}.47$ respectively(t=3.275, p= .000). 3. 86.20%(75 persons) of the respondents have had received first aid training and the training they received were CPR 82.75%(72 persons), primary survey 81.60%(7l persons), contact to 911 79.30%(69 persons) and wounds treatment(lacerated wounds, bum and chilblains) 75.86%( 66 persons) in order. 4. As for the questions that ask on confidence of first-aid treatment, 80% answered they are confident on some limited kinds of treatments, 16% said they are confident and 4% answered they lack confidence. As for the treatment that they can show the highest confidence, wounds treatment topped the list with 93.24%, nose bleeding and removing foreign substance, and stanching followed the list with 82.43% and 81.08% respectively. 5. 97.67% of respondents said they were willing to take training and 89.62% answered to take the training to deal with emergency situations that are taking place in their schools. As for the question that asks for the most wanted treatments, CPR topped the list with 32.18%(28 persons) and treatment for obstruction of airway and shock followed the list with 35.63%(31 persons) and 27.59%(24 persons). Conclusion : Currently, first aid treatment has been centered on CPR, primary survey, contact to 119 and wounds treatment. However, since most of school health educator are fairly confident with wounds treatment, stanching and other first aids, in future training it will be more desirable to focus on CPR and treatment for obstruction of airway and shock that were shown to be most wanted by school health educator.

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Evaluation of Serological Surveillance System for Improving Foot-and-Mouth Disease Control (구제역 관리를 위한 혈청학적 예찰계획 평가)

  • Pak, Son-Il;Shin, Yeun-Kyung
    • Journal of Veterinary Clinics
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    • v.30 no.4
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    • pp.258-263
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    • 2013
  • The primary goal of this study was to compute sample sizes required to achieve the each aim of a variety of foot-and-mouth disease (FMD) surveillance programs, using a statistically valid technique that takes the following factors into account: sensitivity (Se) and specificity (Sp) of diagnostic test system, desired minimum detectable prevalence, precision, population size, and desired power of the survey. In addition, sample sizes to detect FMD if the disease is present and also as proof of freedom were computed. The current FMD active surveillance programs consist of clinical, virological, and serological surveillance. For the 2012 serological surveillance, annual sample sizes (n = 265,065) are planned at four separate levels: statistical (n = 60,884) and targeted (n = 115,232) at breeding pig farms and slaughter house, in together with the detection of structural proteins (SP) antibodies against FMD (n = 88,949). Overall, the sample size was not designed taking the specific aims of each surveillance stream into account. The sample sizes for statistical surveillance, assuming stratified two-stage sampling technique, was based to detect at least one FMD-infected case in the general population. The resulting sample size can be used to obtain evidence of freedom from FMD infection, not for detecting animals that have antibodies against FMD virus non-structural proteins (NSP). Additionally, sample sizes for targeted surveillance were not aimed for the population at risk, and also without consideration of statistical point of view. To at least the author's knowledge, sampling plan for targeted, breeding pig farms and slaughter house is not necessary and need to be included in the part of statistical surveillance. Assuming design prevalence of 10% in an infinite population, a total of 29 animals are required to detect at least one positive with probability of 95%, using perfect diagnostic test system (Se = Sp = 100%). A total of 57,211 animals needed to be sampled to give 95% confidence of estimating SP prevalence of 80% at the individual animal-level with a precision of ${\pm}5%$, assuming 800 herds with an average 200 heads per farm, within-farm variance of 0.2, between-farm variance of 0.05, cost ratio of 100:1 of farm against animals. Furthermore, 779,736 animals were required to demonstrate FMD freedom, and the sample size can further be reduced depending on the parameters assumed.

Association Study of Single-Nucleotide Polymorphism in Lymphotoxin Alpha Gene and Bipolar I Disorder (제1형 양극성 장애와 Lymphotoxin Alpha 유전자 단일염기 다형성 연관 연구)

  • Kim, Sang-Ha;Jun, Tae-Youn
    • Korean Journal of Biological Psychiatry
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    • v.19 no.3
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    • pp.134-139
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    • 2012
  • Objectives : Proinflammatory process has been implicated as an underlying mechanism of bipolar disorder and schizophrenia. Previous studies have suggested a possible role of lymphotoxin alpha (LTA) gene in the development of schizophrenia and have prompted further investigation in bipolar patients. Association of the LTA +252A/G polymorphism with susceptibility to bipolar I disorder itself as well as with vulnerability among a subset of psychotic bipolar patients were tested. Methods : DNA extraction was done by a standard method and genotyping was carried out by polymerase chain reaction-restriction fragment length polymorphism (PCR-RFLP) method in 114 Korean patients with bipolar I disorder and 202 healthy controls. SPSS v18.0 was used for statistical analysis. Comparisons of the genotype and allele distributions in LTA +252A/G polymorphism were made using a chi-square test. The genotype and allele associations were also evaluated using odds ratio (OR) and 95% confidence interval (CI). Statistical significance was accepted when p was < 0.05. Results : No significant association was found between the LTA +252A/G polymorphism and bipolar disorder. However, LTA +252G allele was present with significantly higher frequency among bipolar patients with psychotic features compared to those without (${\chi}^2$ = 4.69, p = 0.034, OR = 2.495, 95% CI = 1.069-5.827). Conclusion : The results suggest that the allele LTA +252G of the polymorphism may be associated with the psychotic subset of bipolar disorder but not with bipolar I disorder itself. Adequately powered subsequent studies should be conducted.

Statistical Analysis and Countermeasure about Fire Mistaken Dispatch (통계적 분석을 통한 화재 오인출동의 현황과 대책)

  • Eom, Sang-Yong;Kim, Kyoung-Jin;Lee, Su-Kyung
    • Fire Science and Engineering
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    • v.27 no.2
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    • pp.89-96
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    • 2013
  • In this research, the fire mistaken dispatch records for the past 11 years have been analyzed by using a statistic technique. Fire mistaken dispatch occurred yearly average $48,371{\pm}5,763$ time at 95 % confidence level. This is 1.2 times more than the dispatch for extinguishing the fire. Fire mistaken dispatch has been increased mainly by malfunctioning alarm among other various reasons and the reason of mistaken dispatch is different depending on the population of the region. In big cities, the burning smell accounts for the most of mistaken dispatch but in rural areas, the garbage incineration is the major reason for mistaken dispatch. As a result of calculating the mean time between fire mistaken dispatches (MTBFmd) by region, MTBFmd of Daejeon is 20.61 hr/time and its reliability is 95.26 % at t=1 hr. On the other hand, the MTBFmd of Gyeonggi is 0.58 hr/time and its reliability is 17.91 % at t=1 hr.

Evaluation of Gustatory Function in Patients with Sleep Disordered Breathing

  • Ahn, Jong-Mo;Bae, Kook-Jin;Yoon, Chang-Lyuk;Ryu, Ji-Won
    • Journal of Oral Medicine and Pain
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    • v.39 no.1
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    • pp.10-14
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    • 2014
  • Purpose: The aim of this study is to evaluate the difference between gustatory functions in a sleep disordered breathing (SDB) group and a control group. The pathogenesis of SDB has not been fully understood. Though the precise contributions of neuromuscular and anatomical factors on SDB pathogenesis are still debated, we hypothesized that the gustatory dysfunction could be predisposed to SDB. Methods: All patients were diagnosed as SDB by polysomnography (PSG). On the basis of PSG results, patients were divided into 3 groups: snoring, mixed, and obstructive sleep apnea (OSA). The control group comprised healthy volunteers who were the same age as those of the SDB group and whose breathing was verified as normal using a portable sleep monitor device. The patient group and the control group were evaluated for gustatory functions with an electrogustometry (EGM). The electrical taste thresholds were measured in the anterior, midlateral, and posterior sides of the tongue and soft palatal regions, both sides. To find out the difference in EGM scores, statistical analysis was performed using the Kruskal-wallis and Mann-Whitney U test with 95% confidence interval and p<0.05 significance level. Results: The patients with SDB had higher EGM scores than the control group at all spots tested, except for the right midlateral of the tongue, and there was a statistical significance in the comparison between the control group and the divided SDB groups, respectively. Among the divided SDB groups, the snoring group had the most significant differences in the number of the measured spots, but there was no difference among the snoring, mixed, and OSA groups. Conclusions: These results may suggest that neurologic alterations with sleep disordered breathing could be associated with gustatory dysfunction. In the future, further systemic studies will be needed to confirm this study.

A Study on the Method of Building 3D GIS Database Using the Statistical Estimating Methods of Well Log for Balancing Seismic Data (탄성파 자료 보정용 검층 기록의 통계적 추정방법을 이용한 3차원 GIS DB 구축방법에 관한 연구)

  • Um, Jong-Seok
    • Journal of Korea Spatial Information System Society
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    • v.5 no.1 s.9
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    • pp.39-47
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    • 2003
  • The purpose of this paper is to present the method of acquiring 3D GIS data using the statistical estimating methods of Well Log for balancing Seismic data. We use the reflection coefficients of seismic data to get the parameters for the reservoir characterization and we balance the reflection coefficients of seismic data using well log to increase the confidence of the estimated result. Well logs are required to balance the reflection coefficients at the point where seismic data are acquired. In this research, we discuss the geostatistical estimation methods and we applied these methods to real data. Kriging gives high weights to the close well logs, which means estimated results are mainly affected by close well log. High value of cross variograms gave big difference on cokriging result comparing to kriging results and low value of cross variogram gave little differences.

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Achievement and satisfaction research of the undergraduate orchestra club activities - A convergent aspects of statistical method and opinion mining (오케스트라 동아리 참여 대학생의 성취도 및 만족도 조사 - 통계적 방법과 오피니언 마이닝의 융합적 측면)

  • Choi, Sui;Choi, Kyoungho
    • Journal of the Korea Convergence Society
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    • v.6 no.4
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    • pp.25-31
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    • 2015
  • General student orchestra activity is known as desirable hobby for students of adolescent period, developing their creativity and sensitivity, give students sense of belonging and stability by resolving their social, emotional anxiety. Accordingly, his research investigated whether orchestra club activity also has similar effect on university students. As a result unlike of adolescent students, orchestra activity turned out to be not that helpful for the social, self-confidence improvement of university students, though achievement of the activity itself was high. Despite of the result, there exist positive factors; obviously the activity has positive factors analyzing through recognition analysis (opinion mining) using big data. Therefore national support is required also for the orchestra activity of the undergraduates.

A Study on The Comparison of Mechanical Property Between The Staggered Stud Wood Wall and The Standard Wood Frame Wall (일반벽체와 교호 샛기둥 벽체의 역학적 성능 비교 연구)

  • Shim, Jae-Kwang;Kim, Gwang-Chul
    • Journal of the Korean Wood Science and Technology
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    • v.45 no.5
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    • pp.640-649
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    • 2017
  • A comparative research on the traditional standard wood walls and other light-frame wood walls is necessary to expand the base of wooden buildings and improve consumer satisfaction. Therefore, in this research we looked for new possibilities through comparison of performance between standard wood wall and newly presented staggered stud wood wall. First, the strength characteristics of staggered stud wood walls were evaluated and the those of standard wood walls were compared. The ultimate load of the standard wall was larger than that of the staggered stud wood wall, because the cross section of the wood making up the standard wood wall was larger than that of the staggered stud wood wall. However, the statistical analysis between the two groups didn't showed a significance of 95% confidence level. This means that, staggered stud wood walls have shown the possibility of replacing the standard wood wall. Because the cross-section of the stud in the staggered stud wood walls is smaller than that of the standard wall, the material can be saved. Therefore, staggerd wood stud wall is judged to be more economical than the standard wall. In addition, since the area of the insulation also increases, improvement of the heat bridge is also expected.