• Title/Summary/Keyword: Occurrence probability

Search Result 547, Processing Time 0.021 seconds

Effects of Psychological and Physiological Factors on Asthma in Korean Adults (심리 및 생리적 요인이 성인천식에 미치는 영향)

  • Lee, Kyung Hee
    • Science of Emotion and Sensibility
    • /
    • v.23 no.2
    • /
    • pp.13-22
    • /
    • 2020
  • This study aimed to investigate the association between asthma and emotions, such as depression, stress, and health awareness. We observed the effects of blood indices on asthma in Korean adults. Data from 5852 adults were taken from the 2017 Seventh Korea National Health and Nutrition Examination Survey and analyzed using a multivariate logistic regression model. The probability of asthma occurrence in over 65 years old was higher than in 19-44 years old (OR = 1.48), and asthma occurrence was high in subjects with low educational (OR = 1.89) and income (OR = 2.07) levels. With regard to marital status, singleness and divorce and dye were found to have increased the probability of asthma occurrence by 1.62- and 2.30-folds, respectively. The restriction of activities was another factor that increased with asthma occurrence (OR = 2.39). In terms of emotions, general health awareness was significantly 3.45 times increased the probability of asthma occurrence at their health bad awareness. Furthermore, depression (OR = 1.782) was shown to have increased asthma occurrence. The blood index of C-CRP 1.12 times increased the probability of asthma occurrence. The factors that influenced asthma occurrence were age, education, income, marital status, the restriction of activities, general health awareness, depression, and C-CRP. Emotional factors and blood indices are potential risk factors for the development of asthma in Korean adults. By understanding the increased risks of asthma occurrence with general characteristics and emotional factors and blood indices, the management and prevention of asthma should include the management of emotional factors.

Why do we get Negative Variance Components in ANOVA

  • Lee, Jang-Taek
    • Communications for Statistical Applications and Methods
    • /
    • v.8 no.3
    • /
    • pp.667-675
    • /
    • 2001
  • The usefulness of analysis of variance(ANOVA) estimates of variance components is impaired by the frequent occurrence of negative values. The probability of such an occurrence is therefore of interest. In this paper, we investigate a variety of reasons for negative estimates under one way random effects model. It can be shown, through simulation, that this probability increases when the number of treatments is too small for fixed total observations, unbalancedness of data is severe, ratio of variance components is too small, and data may contain many outliers.

  • PDF

DISTRIBUTIONS OF PATTERNS OF TWO FAILURES SEPARATED BY SUCCESS RUNS OF LENGTH $\textit{k}$

  • Sen, Kanwar;Goyal, Babita
    • Journal of the Korean Statistical Society
    • /
    • v.33 no.1
    • /
    • pp.35-58
    • /
    • 2004
  • For fixed positive integers and $\textit{k}\;(n\;{\geq}\;{\textit{k}}\;+\;2)$, the exact probability distributions of non-overlapping and overlapping patterns of two failures separated by (i) exactly $textsc{k}$ successes, (ii) at least $\textit{k}$ successes and (iii) at most $\textit{k}$ successes have been obtained for Bernoulli independent and Markov dependent trials by using combinatorial technique. The waiting time distributions for the first occurrence and the $r^{th}$ (r > 1) occurrence of the patterns have also been obtained.

An analysis of limiting conditions of excess inrush currents and a derivation of the probability equations of inrush current occurrence (돌입전류의 제어조건 해석 및 돌입전류 발생 확률식의 유도)

  • 박영문
    • 전기의세계
    • /
    • v.14 no.5
    • /
    • pp.8-14
    • /
    • 1965
  • Because of the flat slope of the magnetic characteristic curves at high saturation, the transformer inrush current peakes may assume an extreme magnitude. Even though such is rarely any danger to the transformer itself, the currents can cause serious problems in associated apparatus. This paper has analyzed various limiting factors of excess inrush currents, and then has suggested how to determine the frequency of encountering the inrush current peaks higher than an arbitrarily chosen value by deriving the probability equations of inrush current occurrence.

  • PDF

Reliability Analysis under the Competing Risks (경쟁적 위험하에서의 신뢰성 분석)

  • Baik, Jaiwook
    • Journal of Applied Reliability
    • /
    • v.16 no.1
    • /
    • pp.56-63
    • /
    • 2016
  • Purpose: The purpose of this study is to point out that the Kaplan-Meier method is not valid to calculate the survival probability or failure probability (risk) in the presence of competing risks and to introduce more valid method of cumulative incidence function. Methods: Survival analysis methods have been widely used in biostatistics division. However the same methods have not been utilized in reliability division. Especially competing risks cases, where several causes of failure occur and the occurrence of one event precludes the occurrence of the other events, are scattered in reliability field. But they are not noticed in the realm of reliability expertism or they are analysed in the wrong way. Specifically Kaplan-Meier method which assumes that the censoring times and failure times are independent is used to calculate the probability of failure in the presence of competing risks, thereby overestimating the real probability of failure. Hence, cumulative incidence function is introduced and sample competing risks data are analysed using cumulative incidence function and some graphs. Finally comparison of cumulative incidence functions and regression type analysis are mentioned briefly. Results: Cumulative incidence function is used to calculate the survival probability or failure probability (risk) in the presence of competing risks and some useful graphs depicting the failure trend over the lifetime are introduced. Conclusion: This paper shows that Kaplan-Meier method is not appropriate for the evaluation of survival or failure over the course of lifetime. In stead, cumulative incidence function is shown to be useful. Some graphs using the cumulative incidence functions are also shown to be informative.

Analysis of Slope Hazard Probability around Jinjeon-saji Area located in Stone Relics (석조문화재가 위치한 진전사지 주변의 사면재해 가능성 분석)

  • Kim, Kyeong-Su;Song, Young-Suk;Cho, Yong-Chan;Jeong, Gyo-Cheol
    • The Journal of Engineering Geology
    • /
    • v.18 no.3
    • /
    • pp.303-309
    • /
    • 2008
  • A probability of slope hazards was predicted at a natural terrain around the stone relics of Jinjeon-saji area, which is located in Yangyang, Kangwon Province. As the analyzing results of field investigation, laboratory test and geology and geomorphology data, the effect factors of landslides occurrence were evaluated. Also, the landslides prediction map was made up using the prediction model by the effect factors. The landslide susceptibility of stone relics was investigated as the grading classification of occurrence probability. In the landslides prediction map, the high probability area was $3,489m^2$ and it was 10.1% of total prediction area. The high probability area has over 70% of occurrence probability. If landslides are occurred at the predicted area, the three stories stone pagoda of Jinjeon-saji(National treasure No. 122) and the stone lantern of Jinjeon-saji(Treasure No.439) will be collapsed by debris flow.

Development of Time-Dependent Reliability-Based Design Method Based on Stochastic Process on Caisson Sliding of Vertical Breakwater (직립방파제의 케이슨 활동에 대한 확률과정에 기반한 시간의존 신뢰성 설계법 개발)

  • Kim, Seung-Woo;Cheon, Sehyeon;Suh, Kyung-Duck
    • Journal of Korean Society of Coastal and Ocean Engineers
    • /
    • v.24 no.5
    • /
    • pp.305-318
    • /
    • 2012
  • Although the existing performance-based design method for the vertical breakwater evaluates an average sliding distance during an arbitrary time, it does not calculate the probability of the first occurrence of an event exceeding an allowable sliding distance(i.e. the first-passage probability). Designers need information about the probability that the structure is damaged for the first time for not only design but also maintenance and operation of the structure. Therefore, in this study, a time-dependent reliability design method based on a stochastic process is developed to evaluate the first-passage probability of caisson sliding. Caisson sliding can be formulated by the Poisson spike process because both occurrence time and intensity of severe waves causing caisson sliding are random processes. The occurrence rate of severe waves is expressed as a function of the distribution function of sliding distance and mean occurrence rate of severe waves. These values simulated by a performance-based design method are expressed as multivariate regression functions of design variables. As a result, because the distribution function of sliding distance and the mean occurrence rate of severe waves are expressed as functions of significant wave height, caisson width, and water depth, the first-passage probability of caisson sliding can be easily evaluated.

Selective Feature Extraction Method Between Markov Transition Probability and Co-occurrence Probability for Image Splicing Detection (접합 영상 검출을 위한 마르코프 천이 확률 및 동시발생 확률에 대한 선택적 특징 추출 방법)

  • Han, Jong-Goo;Eom, Il-Kyu;Moon, Yong-Ho;Ha, Seok-Wun
    • Journal of the Korea Institute of Information and Communication Engineering
    • /
    • v.20 no.4
    • /
    • pp.833-839
    • /
    • 2016
  • In this paper, we propose a selective feature extraction algorithm between Markov transition probability and co-occurrence probability for an effective image splicing detection. The Features used in our method are composed of the difference values between DCT coefficients in the adjacent blocks and the value of Kullback-Leibler divergence(KLD) is calculated to evaluate the differences between the distribution of original image features and spliced image features. KLD value is an efficient measure for selecting Markov feature or Co-occurrence feature because KLD shows non-similarity of the two distributions. After training the extracted feature vectors using the SVM classifier, we determine whether the presence of the image splicing forgery. To verify our algorithm we used grid search and 6-folds cross-validation. Based on the experimental results it shows that the proposed method has good detection performance with a limited number of features compared to conventional methods.

Fuzzy-technique-based expert elicitation on the occurrence probability of severe accident phenomena in nuclear power plants

  • Suh, Young A;Song, Kiwon;Cho, Jaehyun
    • Nuclear Engineering and Technology
    • /
    • v.53 no.10
    • /
    • pp.3298-3313
    • /
    • 2021
  • The objective of this study is to estimate the occurrence probabilities of severe accident phenomena based on a fuzzy elicitation technique. Normally, it is difficult to determine these probabilities due to the lack of information on severe accident progression and the highly uncertain values currently in use. In this case, fuzzy set theory (FST) can be best exploited. First, questions were devised for expert elicitation on technical issues of severe accident phenomena. To deal with ambiguities and the imprecision of previously developed (reference) probabilities, fuzzy aggregation methods based on FST were employed to derive the occurrence probabilities of severe accidents via four phases: 1) choosing experts, 2) quantifying weighting factors for the experts, 3) aggregating the experts' opinions, and 4) defuzzifying the fuzzy numbers. In this way, this study obtained expert elicitation results in the form of updated occurrence probabilities of severe accident phenomena in the OPR-1000 plant, after which the differences between the reference probabilities and the newly acquired probabilities using fuzzy aggregation were compared, with the advantages of the fuzzy technique over other approaches explained. Lastly, the impact of applying the updated severe accident probabilities on containment integrity was quantitatively investigated in a Level 2 PSA model.

Estimation of Potential Natural Vegetation using the Estimate to Probability Distribution of Vegetation in Bukhansan National Park (식생 분포 확률 추정을 통한 북한산 국립공원의 잠재자연식생 추정)

  • Shin, Jin-Ho;Yeon, Myung-Hun;Yang, Keum-Chul
    • Journal of the Korean Society of Environmental Restoration Technology
    • /
    • v.16 no.3
    • /
    • pp.41-53
    • /
    • 2013
  • The study for the estimation potential natural vegetation was estimated the occurrence probability distribution using geographic information system(GIS) in Bukhansan National Park. Correlation and factor analysis were analyzed to estimate probability distribution. Coefficients were calculated by logistic regression analysis. Correlation coefficients were significantly at the 0.01 level. Commonality of elevation, annual mean temperature, warmth index and potential evapotranspiration were high value, but topographic index was low value. Communities of over the 0.3 points distribution probability, Quercus mogolica communities were the largest area, 76,940,900 $m^2$, Pinus densiflora communities area was 860,800 $m^2$, Quercus acutissima communities area was 500,100 $m^2$ and Quercus variabilis communities area was 1,000 $m^2$, but Q. aliena, Q. serrata, Carpinus laxiflora and Zelcova serrata communities was not appeared. Therefore, potential national vegetation of Bukhansan national park was likely to be Q. mongolica community, P. densiflora community, Q. acutissima community and Q. variabilis community.