• 제목/요약/키워드: beta distribution

검색결과 776건 처리시간 0.024초

입상체시료의 공극비의 빈도분포 (The Frequency Distribution of Void Ratio of Granular Materials)

  • 도덕현;고재만;오규태
    • 한국지반공학회지:지반
    • /
    • 제4권3호
    • /
    • pp.5-18
    • /
    • 1988
  • 3종의 입상체시료를 대상으로 공극비의 빈도분포, 상대밀도 전단강도 등에 대한 시험연구결과 (1) 유리알의 경우 공극비의 빈도분포는 Shahinpoorl가 제안한 음의 지수분포에 접근하며 입자의 모양은 구형에서 각형의 순으로 변화되는 반면에 조밀한 공극의 빈도는 감소하며 Beta분포로서 잘 나타냈다. (2) 전 시료에서 공극비의 표준편차는 시료의 상대밀도와 입자의 구형성이 감소함에 따라 증가하였다. (3) 전단강도는 평균공극비와 표준편차의 함수일 뿐만 아니라 공극비 분포의 확율밀도함수이다. (4) 공극비는 정도분포가 조밀한 공극쪽으로 기울수록 시료의 전단강도는 더 크며 이의 역도 또한 같다.

  • PDF

Quantitative microbial risk assessment of Campylobacter jejuni in jerky in Korea

  • Ha, Jimyeong;Lee, Heeyoung;Kim, Sejeong;Lee, Jeeyeon;Lee, Soomin;Choi, Yukyung;Oh, Hyemin;Yoon, Yohan
    • Asian-Australasian Journal of Animal Sciences
    • /
    • 제32권2호
    • /
    • pp.274-281
    • /
    • 2019
  • Objective: The objective of this study was to estimate the risk of Campylobacter jejuni (C. jejuni) infection from various jerky products in Korea. Methods: For the exposure assessment, the prevalence and predictive models of C. jejuni in the jerky and the temperature and time of the distribution and storage were investigated. In addition, the consumption amounts and frequencies of the products were also investigated. The data for C. jejuni for the prevalence, distribution temperature, distribution time, consumption amount, and consumption frequency were fitted with the @RISK fitting program to obtain appropriate probabilistic distributions. Subsequently, the dose-response models for Campylobacter were researched in the literature. Eventually, the distributions, predictive model, and dose-response model were used to make a simulation model with @RISK to estimate the risk of C. jejuni foodborne illness from the intake of jerky. Results: Among 275 jerky samples, there were no C. jejuni positive samples, and thus, the initial contamination level was statistically predicted with the RiskUniform distribution [RiskUniform (-2, 0.48)]. To describe the changes in the C. jejuni cell counts during distribution and storage, the developed predictive models with the Weibull model (primary model) and polynomial model (secondary model) were utilized. The appropriate probabilistic distribution was the BetaGeneral distribution, and it showed that the average jerky consumption was 51.83 g/d with a frequency of 0.61%. The developed simulation model from this data series and the dose-response model (Beta Poisson model) showed that the risk of C. jejuni foodborne illness per day per person from jerky consumption was $1.56{\times}10^{-12}$. Conclusion: This result suggests that the risk of C. jejuni in jerky could be considered low in Korea.

확률분포모형을 이용한 하루살이속(Ephemera) 4종의 고도구배에 따른 서식처적합도 평가 (Estimation on Altitudinal Spectrum of Suitability for Four Species of the Mayfly Genus Ephemera (Ephemeroptera: Ephemeridae) Using Probability Distribution Models)

  • 공동수;강보미
    • 한국물환경학회지
    • /
    • 제39권4호
    • /
    • pp.302-315
    • /
    • 2023
  • Distribution characteristics and altitudinal gradient of four species (E. strigata, E. separigata, E. orientalis-sachalinensis group) of the mayfly genus Ephemera (Order Ephemeroptera) were analyzed with probability distribution models (exponential, normal, lognormal, logistic, Weibull, gamma, beta, Gumbel). Data was collected from 23,846 sampling units of 6,787 sites in Korea from 2010 to 2021. The beta distribution model showed the best fit for positively skewed E. orientalis-sachalinensis and little-skewed E. strigata along with altitudinal gradient. The reversed lognormal distribution model showed the best-fit for negatively skewed E. separigata. E. orientalis-sachalinensis distributed at the range of altitude 1~700 m (mean 251 m, median 226 m, mode 124 m, and standard deviation 161 m), E. strigata distributed at the range of altitude 5~871 m (mean 474 m, median 478 m, mode 492 m, and standard deviation 200 m), E. separigata distributed at the range of altitude 7~846 m (mean 620 m, median 659 m, mode 760 m, and standard deviation 181 m). Altitudinal habitat suitability ranges were estimated to be 42~257 m for E. orientalis-sachalinensis, 335~644 m for E. strigata, and 641~824 m for E. separigata. Based on the altitudinal spectrum of suitability and altitude-related temperature analysis results, E. orientalis-sachalinensis was estimated to be thermophilic, E. strigata to be mesophilic, and E. separigata to be thermophobic. This is the first national-scale evaluation of the altitudinal distribution of Ephemera in Korea. These results will be used in a further research study on altitudinal shift of the species of Ephemera under climate change.

토끼 태자에 형성시킨 구순열상의 치유과정에서 수종 성장인자 분포에 관한 연구 (A STUDY ON THE DISTRIBUTION OF SEVERAL GROWTH FACTORS IN THE ARTIFICIALLY CHEATED CLEFT LIP WOUND HEALING OF RABBIT FETUSES)

  • 백승학;양원식
    • 대한치과교정학회지
    • /
    • 제27권5호
    • /
    • pp.683-696
    • /
    • 1997
  • 성체의 상처 치유과정중 반흔조직 형성에 수종의 성장인자가 관련이 있는 것으로 보고되고 있으나, 태자의 피부상처가 반흔형성없이 치유되는 기전에 관한 성장인자의 역할은 아직 알려져 있지 않다. 따라서 본 연구의 목적은 토끼태자의 상처 치유과정에서 반흔조직의 형성과 관련이 있는 수종 성장인자의 분포를 조사하기 위한 것이다. 뉴질랜드산 흰 토끼를 임신 3기의 중반인 24일째에 자궁절개술을 시행하고 태자에 인위적으로 구순열상을 만든 후, 봉합한 군(봉합군)과 봉합하지 않은 군(비봉합군), 정상대조군(sham operated control group)으로 나누고 이들을 각각 수술후 1, 2, 3, 5, 7일째에 희생시켜 상처치유에 대한 육안관찰 소견과 H & E 염색 소견 및 $TGF-{\beta}1,\;TGF-{\beta}2$, PDGF, bFGF의 면역조직화학적 염색 소견을 관찰하여 다음과 같은 결론을 얻었다. 1. 봉합군과 비봉합군에서 전기간동안 염증반응과 반흔조직의 형성 그리고 신생 혈관의 형성 증가는 없었다. 2. 비봉합군의 재상피화가 봉합군에 비해 다소 느렸다. 3. bFGF는 정상대조군, 봉합군과 비봉합군에서 차이가 없었다. 4. PDGF는 봉합군과 비봉합군에서 1, 2일군에서 증가하였다가 그후 감소하여 정상대조군과 차이가 없었다. 5. $TGF-{\beta}$는 봉합군과 비봉합군에서 1, 2일군에서 약간 증가하였다가 그후 감소하여 정상대조군과 차이가 없었다. $TGF-{\beta}1$에 비하여 $TGF-{\beta}2$의 검출양이 많았다.

  • PDF

ON ESTIMATION OF NEGATIVE POLYA-EGGENBERGER DISTRIBUTION AND ITS APPLICATIONS

  • Hassan, Anwar;Bilal, Sheikh
    • Journal of the Korean Society for Industrial and Applied Mathematics
    • /
    • 제12권2호
    • /
    • pp.81-95
    • /
    • 2008
  • In this paper, the negative Polya-Eggenberger distribution has been introduced by compounding negative binomial distribution with beta distribution of I-kind which generates a number of univariate contagious or compound (or mixture of) distributions as its particular cases. The distribution is unimode, over dispersed and all of its positive and negative integer moments exist. The difference equation of the proposed model shows that it is a member of the Ord's family of distribution. Some of its interesting properties have been explored besides different methods of estimation been discussed. Finally, the parameters of the proposed model have been estimated by using a computer programme in R-software. Application of the proposed model to some data, available in the literature, has been given and its goodness of fit demonstrated.

  • PDF

피어슨 곡선족에서 온 표본분포들에 관한 소고

  • 구자흥;유동선
    • 한국수학사학회지
    • /
    • 제13권1호
    • /
    • pp.1-14
    • /
    • 2000
  • The first part of this thesis discusses the Pearson's Curve Family which gives $\beta$distribution, $\Gamma$-distribution, $X^2$-distribution and t-distribution. The second part of this thesis gives some brief process of calculations for normal distribution density and t-distribution density by the 7-th type Curve of Pearson's Curve Family. Finally, a conclusion arrives that Student(Gosset) could not find out his famous 'Student's t-distribution' without his attending of 'Pearson's Differential Equation' class taught by Pearson himself when he was a senior student. However, if he had got a professorship at the Pearson Statistics Laboratory, the University of London, then he could not have found 'Student's t-distribution' for small sampling technique of modern statistics.

  • PDF

Error Rate for the Limiting Poisson-power Function Distribution

  • Joo-Hwan Kim
    • Communications for Statistical Applications and Methods
    • /
    • 제3권1호
    • /
    • pp.243-255
    • /
    • 1996
  • The number of neutron signals from a neutral particle beam(NPB) at the detector, without any errors, obeys Poisson distribution, Under two assumptions that NPB scattering distribution and aiming errors have a circular Gaussian distribution respectively, an exact probability distribution of signals becomes a Poisson-power function distribution. In this paper, we show that the error rate in simple hypothesis testing for the limiting Poisson-power function distribution is not zero. That is, the limit of ${\alpha}+{\beta}$ is zero when Poisson parameter$\kappa\rightarro\infty$, but this limit is not zero (i.e., $\rho\ell$>0)for the Poisson-power function distribution. We also give optimal decision algorithms for a specified error rate.

  • PDF

조피볼락, 용치놀래기, 송곳니베도라치 및 졸복 장관의 복합당질 성상 및 분포 (Characterization and Distribution of Glycoconjugates in the Intestines of Sebastes schlegeli, Halichoeres poecilopterus, Bryzoichthys lysimus, and Takifugu pardalis.)

  • 정길남
    • 생명과학회지
    • /
    • 제18권6호
    • /
    • pp.782-788
    • /
    • 2008
  • 경골어류 4종(조피볼락, 용치놀래기, 송곳니베도라치 및 졸복) 장관의 복합당질 성상의 차이를 밝히기 위해 장을 네 부위로 나누워 아홉 종류의 biotinylated lectin들(DBA, SBA, PNA, BSL- I , RCA- I , sWGA, UEA- I 및 Con A)로 반응시켰다. 조피볼락을 제외하면 부위에 따른 차이는 없었다. 용치놀래기 장 상피는 모든 부위에서 D-glucose/mannose 잔기를 함유하고 있었다. 조피볼락, 송곳니베도라치 및 졸복 장 모든 부위에서는 정도의 차이는 있지만 ${\beta}$-N-acetyl-D-gal-actosamine가 함유되어 있었다. 또한 조피볼락의 근위장, 중간장 및 원위장에는 galactose-${\beta}$-1,3-N-acetyl-D-galactosamine 및 ${\alpha}$-D-galactose도 함유되어 있었으나 직장에는 이들 당 잔기들이 함유되어 있지 않았다. 송곳니베도라치에는 ${\beta}$-N- acetyl-D-galactosamine 외에 ${\beta}$-N-acetyl-D-glucosamine 및 D-glucose/mannose도 발견되었으며, 졸복에서는 Galactose-${\beta}$-1,3-N-acetyl-D-galactosamine, D-galactose 및 D-glucose/mannose도 발견되었다.

신규 개발하는 소모성 발사체의 베이지안 신뢰도 추정 (Bayesian Reliability Estimation of a New Expendable Launch Vehicle)

  • 홍혜진;김경미
    • 품질경영학회지
    • /
    • 제42권2호
    • /
    • pp.199-208
    • /
    • 2014
  • Purpose: This paper explains how to obtain the Bayes estimates of the whole launch vehicle and of a vehicle stage, respectively, for a newly developed expendable launch vehicle. Methods: We determine the parameters of the beta prior distribution using the upper bound of the 60% Clopper-Pearson confidence interval of failure probability which is calculated from previous launch data considering the experience of the developer. Results: Probability that a launch vehicle developed from an inexperienced developer succeeds in the first launch is obtained by about one third, which is much smaller than that estimated from the previous research. Conclusion: The proposed approach provides a more conservative estimate than the previous noninformative prior, which is more reasonable especially for the initial reliability of a new vehicle which is developed by an inexperienced developer.

황동볼트 손상원인 분석사례

  • 정남근
    • 열병합발전
    • /
    • 통권30호
    • /
    • pp.21-25
    • /
    • 2002
  • According to recent Korea Electric Power Company report, yearly distribution line brass cramp bolts failure summed up to 4,400 cases emerging as one of main local break-down causes. Naturally, the need for the investigation was proposed To determine the root cause of the cramp bolt failures, mechanical and metallurgical investigation were performed for 90 samples which collected from various sites. For the understanding of the geometric characteristics, stress distribution was evaluated by CAE program and proof load of each bolts was tested. The SEM&EDS was used for metallurgical investigation. Through the investigation, the root causes of failures were confirmed. All damaged bolts showed intergrannular fracture mode and the all fractured bolt showed ß phase morphology contrast to the a&ß mixture morphology of the non-damaged samples. Additionally, EDS analysis confirmed the existence of lead rich layer on grain boundaries.

  • PDF