• 제목/요약/키워드: statistical representation

검색결과 167건 처리시간 0.027초

Factorization Models and Other Representation of Independence

  • Lee, Yong-Goo
    • Journal of the Korean Statistical Society
    • /
    • 제19권1호
    • /
    • pp.45-53
    • /
    • 1990
  • Factorization models are a generalization of hierarchical loglinear models which apply equally to discrete and continuous distributions. In regular (strictly positive) cases the intersection of two factorization models is another factorization model whose representation is obtained by a simple algorithm. Failure of this result in an irregular case is related to a theorem of Basu on ancillary statistics.

  • PDF

시각적 평균 표상의 신경기제 (Neural correlates of visual mean representation)

  • 정상철;신길호;조신호
    • 인지과학
    • /
    • 제19권1호
    • /
    • pp.75-88
    • /
    • 2008
  • 시각 장면은 중복적인 정보가 많이 포함되어 있다. 우리의 시각체계는 다양하고 중복적인 정보를 처리하기 위해 뇌 용적을 늘이기보다는 들어오는 외부 정보를 요약한다. 유사한 형태의 다양한 정보가 시각체계에 주어지면 시각체계는 정보의 통계적 특성을 추출해 낸다. 이런 통계적 표상의 대표적 형태가 바로 평균 표상이다. 평균 표상의 한 예로 시각 체계에서 계산해 내는 유사한 여러 크기들의 평균 크기를 들 수 있다. 평균 표상은 빠르고 정확하며 비교적 오랜 시간 지속되는 표상이고 평균 표상의 처리과정 또한 병렬적인 처리과정이다. 하지만 지금까지의 통계 표상에 관한 연구는 행동측정방법에 의한 연구였다. 따라서 본 연구는 기능적 자기 공명 영상 기법을 사용하여 통계 표상에 관한 신경기제를 찾고자 하였다. 사전 연구 결과들에 따르면 특정 자극을 연속하여 제시하였을 때 특정 자극을 담당하는 영역에서 자기 공명 영상 신호가 감소함을 알 수 있다. 본 연구에서는 이 반복 감소 현상을 사용하여 원들의 평균이 동일한 자극을 제시하였을 때 우측 후두 영역에서 유의미하게 자기 공명 영상 신호가 감소하는 것을 발견하였다. 이것은 우측 후두 영역이 시각자극에 대한 평균 표상을 처리하는 영역일 수 있음을 시사한다.

  • PDF

A New Integral Representation of the Coverage Probability of a Random Convex Hull

  • Son, Won;Ng, Chi Tim;Lim, Johan
    • Communications for Statistical Applications and Methods
    • /
    • 제22권1호
    • /
    • pp.69-80
    • /
    • 2015
  • In this paper, the probability that a given point is covered by a random convex hull generated by independent and identically-distributed random points in a plane is studied. It is shown that such probability can be expressed in terms of an integral that can be approximated numerically by function-evaluations over the grid-points in a 2-dimensional space. The new integral representation allows such probability be computed efficiently. The computational burdens under the proposed integral representation and those in the existing literature are compared. The proposed method is illustrated through numerical examples where the random points are drawn from (i) uniform distribution over a square and (ii) bivariate normal distribution over the two-dimensional Euclidean space. The applications of the proposed method in statistics are are discussed.

Strong Representations for LAD Estimators in AR(1) Models

  • Kang, Hee-Jeong;Shin, Key-Il
    • Journal of the Korean Statistical Society
    • /
    • 제27권3호
    • /
    • pp.349-358
    • /
    • 1998
  • Consider the AR(1) model $X_{t}$=$\beta$ $X_{t-1}$+$\varepsilon$$_{t}$ where $\beta$ < 1 is an unknown parameter to be estimated and {$\varepsilon$$_{t}$} denotes the independent and identically distributed error terms with unknown common distribution function F. In this paper, a strong representation for the least absolute deviation (LAD) estimate of $\beta$ in AR(1) models is obtained under some mild conditions on F. on F.F.

  • PDF

Weak Convergence of U-empirical Processes for Two Sample Case with Applications

  • Park, Hyo-Il;Na, Jong-Hwa
    • Journal of the Korean Statistical Society
    • /
    • 제31권1호
    • /
    • pp.109-120
    • /
    • 2002
  • In this paper, we show the weak convergence of U-empirical processes for two sample problem. We use the result to show the asymptotic normality for the generalized dodges-Lehmann estimates with the Bahadur representation for quantifies of U-empirical distributions. Also we consider the asymptotic normality for the test statistics in a simple way.

ON ALMOST SURE REPRESENTATIONS FOR LONG MEMORY SEQUENCES

  • Ho, Hwai-Chung
    • 대한수학회지
    • /
    • 제35권3호
    • /
    • pp.741-753
    • /
    • 1998
  • Let G(*) be a Borel function applied to a stationary long memory sequence {X$_{i}$} of standard Gaussian random variables. Focusing on the process {G(X$_{i}$)}, the present paper establishes the almost sure representation for the empirical quantile process, that is, Bahadur's representation, and for the empirical process with respect to sample mean. Statistical applications of the representations are also addressed.sed.

  • PDF

濕性大氣成分에 對한 統計的解析 (Statistical Analysis of Ion Components in Rainwater)

  • 李敏熙;韓義正;元良洙;辛燦基
    • 한국대기환경학회지
    • /
    • 제2권1호
    • /
    • pp.41-54
    • /
    • 1986
  • Methods used for averaging PH's of rainwater and site representation have been studied, Statistical analysis was attempted regarding effects of ionic components on PH's utilizing 847 data altogether obtained in two years, 1984 and 1985. The outcome of the study may be assumarized as follows: 1. Methods for Averaging PH Volume weighted method is considered to be acceptable providing that precipitation is measured at the same time when the samples are taken. Without precipitation data a simple averaging method should be the next choice. 2. Site Representation A statistical method used for optimizing a monitoring newtork was applied using the data collected. Because of a limited number of data, no discernible conclusion can be reached suggesting that the method can serve as a good guide when the data base becomes more reliable. 3. A good correlation appears to exist betwen conductivities and ionic components in rainwater. It would, therefore, be possible to certain extend to estimate ionic concentrations from conductivity measurements by correlation equations. 4. The acidity of rainwater is effected by $SO_4^{2-}, NO_3^-, Cl^- and NH_4^+ with SO_4^{2-}$ being the most significant as demonstrated by standardized regression analysis.

  • PDF

A NEW SYSTEM OF VISUAL PRESENTATION OF ANALYSIS OF TEST PERFORMANCE: THE 'DOUBLE-RING' DIAGRAM

  • Stefadouros Miltiadis A.
    • 대한예방의학회:학술대회논문집
    • /
    • 대한예방의학회 1994년도 교수 연수회(역학)
    • /
    • pp.142-149
    • /
    • 1994
  • Substitution of graphic representation for extensive lists of numerical statistical data is highly desirable by both editors and readers of medical journals, faced with an exploding abundance of contemporary medical literature. A novel graphic tool. the 'double-ring diagram', is described herein which permits visual representation of information regarding certain statistical variables used to describe the performance of a test or physical sign in the diagnosis of a disease. The diagram is relatively easy to construct on the basis of a number of primary data such as the prevalence and the true positive, true negative. false positive and false negative test results. These values are reflected in the diagram along with the values of other statistical variables derived from them. such as the sensitivity. specificity, predictive values for positive and negative test result. and accuracy. This diagram may be useful in visualizing a test's performance and facilitating visual comparison of performance of two or more tests.

  • PDF

건축도면의 형상재현과 비교 (Shape Representation and Comparison of Architectural Drawings)

  • 박수훈
    • 한국CDE학회논문집
    • /
    • 제9권4호
    • /
    • pp.306-314
    • /
    • 2004
  • This paper explains the qualitative shape representation scheme and general shape analysis procedure based on shape feature categories. It takes two different groups of architectural drawings as examples and comparer them so as to confirm that the procedure is capable of comparing one group with another. In order to verify the validity of qualitative shape representation scheme, we used statistical methods as well as symbolic representation and analysis techniques. This paper concludes that two different groups of architectural drawings of similar kind are analyzed to be distinguished and specifically characterized. 11 drawings of Kahn and 13 drawings of Aalto are taken into considerations. Linear regressions are used in characterizing the shape featural relationships.

데이터 퓨전 : 개념, 문제, 대안

  • 한상훈;하덕주;최종후
    • 한국통계학회:학술대회논문집
    • /
    • 한국통계학회 2004년도 학술발표논문집
    • /
    • pp.277-281
    • /
    • 2004
  • 최근 마케팅 현업에서 마이크로 마케팅(Micro Marketing)이 마케팅 기법의 화두로 등장하면서 데이터 퓨전(Data Fusion) 또는 데이터 인리치먼트(Data Enrichment)가 각광받는 영역으로 등장하고 있다. 본 연구에서는 데이터 퓨전의 개념과 그를 둘러싸고 있는 통계적 문제와 그 대안에 대하여 논의한다.

  • PDF