• Title/Summary/Keyword: Random Sets

Search Result 276, Processing Time 0.034 seconds

하이브리드 수의 조건부 기대값 (Conditional Expectation of Hybrid Number)

  • ;최규탁;한성일
    • 한국지능시스템학회:학술대회논문집
    • /
    • 한국퍼지및지능시스템학회 2003년도 춘계 학술대회 학술발표 논문집
    • /
    • pp.18-21
    • /
    • 2003
  • We propose some properties of fuzzy conditional expectation of hybrid number the addition of fuzzy number and random variable using Cartesian product distance for ${\alpha}$-level sets.

  • PDF

의료진단 및 중요 검사 항목 결정 지원 시스템을 위한 랜덤 포레스트 알고리즘 적용 (Application of Random Forest Algorithm for the Decision Support System of Medical Diagnosis with the Selection of Significant Clinical Test)

  • 윤태균;이관수
    • 전기학회논문지
    • /
    • 제57권6호
    • /
    • pp.1058-1062
    • /
    • 2008
  • In clinical decision support system(CDSS), unlike rule-based expert method, appropriate data-driven machine learning method can easily provide the information of individual feature(clinical test) for disease classification. However, currently developed methods focus on the improvement of the classification accuracy for diagnosis. With the analysis of feature importance in classification, one may infer the novel clinical test sets which highly differentiate the specific diseases or disease states. In this background, we introduce a novel CDSS that integrate a classifier and feature selection module together. Random forest algorithm is applied for the classifier and the feature importance measure. The system selects the significant clinical tests discriminating the diseases by examining the classification error during backward elimination of the features. The superior performance of random forest algorithm in clinical classification was assessed against artificial neural network and decision tree algorithm by using breast cancer, diabetes and heart disease data in UCI Machine Learning Repository. The test with the same data sets shows that the proposed system can successfully select the significant clinical test set for each disease.

Large Deviations for random walks with time stationary random distribution function

  • Hong, Dug-Hun
    • 대한수학회지
    • /
    • 제32권2호
    • /
    • pp.279-287
    • /
    • 1995
  • Let $F$ be a set of distributions on R with the topology of weak convergence, and let $A$ be the $\sigma$-field generated by the open sets. We denote by $F_1^\infty$ the space consisting of all infinite sequence $(F_1, F_2, \cdots), F_n \in F and R_1^\infty$ the space consisting of all infinite sequences $(x_1, x_2, \cdots)$ of real numbers. Take the $\sigma$-field $F_1^\infty$ to be the smallest $\sigma$-field of subsets of $F_1^\infty$ containing all finite-dimensional rectangles and take $B_1^\infty$ to be the Borel $\sigma$-field $R_1^\infty$.

  • PDF

On the Almost Certain Rate of Convergence of Series of Independent Random Variables

  • Nam, Eun-Woo;Andrew Rosalsky
    • Journal of the Korean Statistical Society
    • /
    • 제24권1호
    • /
    • pp.91-109
    • /
    • 1995
  • The rate of convergence to a random variable S for an almost certainly convergent series $S_n = \sum^n_{j=1} X_j$ of independent random variables is studied in this paper. More specifically, when $S_n$ converges to S almost certainly, the tail series $T_n = \sum^{\infty}_{j=n} X_j$ is a well-defined sequence of random variable with $T_n \to 0$ a.c. Various sets of conditions are provided so that for a given numerical sequence $0 < b_n = o(1)$, the tail series strong law of large numbers $b^{-1}_n T_n \to 0$ a.c. holds. Moreover, these results are specialized to the case of the weighted i.i.d. random varialbes. Finally, example are provided and an open problem is posed.

  • PDF

Random number sensitivity in simulation of wind loads

  • Kumar, K. Suresh
    • Wind and Structures
    • /
    • 제3권1호
    • /
    • pp.1-10
    • /
    • 2000
  • Recently, an efficient and practical method has been developed for the generation of univariate non-Gaussian wind pressure time histories on low building roofs; this methodology requires intermittent exponential random numbers for the simulation. On the other hand, the conventional spectral representation scheme with random phase is found suitable for the generation of univariate Gaussian wind pressure time histories on low building roofs; this simulation scheme requires uniform random numbers. The dependency of these simulation methodologies on the random number generator is one of the items affecting the accuracy of the simultion result; therefore, an attempt has been made to investigate the issue. This note presents the observed sensitivity of random number sets in repetitive simulations of Gaussian and non-Gaussian wind pressures.

RENEWAL AND RENEWAL REWARD THEORIES FOR T-INDEPENDENT FUZZY RANDOM VARIABLES

  • KIM, JAE DUCK;HONG, DUG HUN
    • Journal of applied mathematics & informatics
    • /
    • 제33권5_6호
    • /
    • pp.607-625
    • /
    • 2015
  • Recently, Wang et al. [Computers and Mathematics with Ap-plications 57 (2009) 1232-1248.] and Wang and Watada [Information Sci-ences 179 (2009) 4057-4069.] studied the renewal process and renewal reward process with fuzzy random inter-arrival times and rewards under the T-independence associated with any continuous Archimedean t-norm. But, their main results do not cover the classical theory of the random elementary renewal theorem and random renewal reward theorem when fuzzy random variables degenerate to random variables, and some given assumptions relate to the membership function of the fuzzy variable and the Archimedean t-norm of the results are restrictive. This paper improves the results of Wang and Watada and Wang et al. from a mathematical per-spective. We release some assumptions of the results of Wang and Watada and Wang et al. and completely generalize the classical stochastic renewal theorem and renewal rewards theorem.

Some Positive Dependent Orderings

  • Tae-Sung Kim;Song-Ho Kim
    • Journal of the Korean Statistical Society
    • /
    • 제25권2호
    • /
    • pp.243-253
    • /
    • 1996
  • Let X and Y be random vectors in R$^{n}$ . A random vector X is 'more associated' than Y if and only if P(X $\in$ A ∩ B) - P(X $\in$ A)P(X $\in$ B) $\geq$ P(Y $\in$ A ∩ B)-P(Y $\in$ A)P(Y $\in$ B) for all open upper sets A and B. By requiring the above inequality to hold for some open upper sets A and B various notions of positive dependence orderings which are weaker than 'more associated' ordering are obtained. First a general theory is given and then the results are specialized to some concepts of a particular interest. Various properties and interrelationships are derived.

  • PDF

가중치 집합 최적화를 통한 효율적인 가중 무작위 패턴 생성 (Efficient Weighted Random Pattern Generation Using Weight Set Optimization)

  • 이항규;김홍식;강성호
    • 전자공학회논문지C
    • /
    • 제35C권9호
    • /
    • pp.29-37
    • /
    • 1998
  • 가중 무작위 패턴 테스트에서 적은 수의 가중 무작위 패턴을 사용하여 높은 고장 검출율을 달성하기 위해서는 최적화된 가중치 집합들을 찾아내야만 한다. 따라서 최적화된 가중치 집합을 찾아내려는 많은 연구가 행해져 왔다. 이 논문에서 결정론적인 테스트 패턴에 대한 샘플링 확률을 기반으로 하여 최적화된 가중치 집합을 효율적으로 찾는 새로운 가중치 집합 최적화 알고리듬을 제한한다. 아울러 시뮬레이션을 통해 적당한 최대해밍거리를 구하는 방법도 소개된다. ISCAS 85 벤치마크 회로에 대한 실험결과는 새로운 가중치 집합 최적화 알고리듬과 적절한 최대 해밍거리를 구하는 방법의 효율성을 뒷받침해 준다.

  • PDF