Journal of the Japanese Society of Computational Statistics
Online ISSN : 1881-1337
Print ISSN : 0915-2350
ISSN-L : 0915-2350
Volume 13, Issue 1
Displaying 1-5 of 5 articles from this issue
  • Hiroshi Yadohisa, Naoto Niki
    2000 Volume 13 Issue 1 Pages 1-14
    Published: 2000
    Released on J-STAGE: December 09, 2009
    JOURNAL FREE ACCESS
    A vector model for representing asymmetry in multidimensional scaling is proposed. Given an asymmetric square matrix of (dis) similarity measures for all pairs of objects in the analysis, and assuming that the locations of objects have already been determined from the symmetric component of the data through some suitable multidimensional scaling model, a set of vectors which represents the latent structure of asymmetry in the data matrix is then determined from the remaining skew-symmetric part of the matrix by the model here in proposed. The discussion is extended to the asymmetric structure of the data, giving indices of several types of asymmetry. A real-data application of the vector model is also described.
    Download PDF (1293K)
  • Tsukio Morita
    2000 Volume 13 Issue 1 Pages 15-24
    Published: 2000
    Released on J-STAGE: December 09, 2009
    JOURNAL FREE ACCESS
    This paper shows that estimates of the latent parameters are much improved by using a new method obtained from numerical research. This method contains a new and unknown parameter p, and it intends to improve on the estimates by appropriately giving this p. A criterion for deciding the value of the optimum parameter p is proposed.
    Download PDF (730K)
  • SeungBae Choi, Yutaka Tanaka
    2000 Volume 13 Issue 1 Pages 25-39
    Published: 2000
    Released on J-STAGE: December 09, 2009
    JOURNAL FREE ACCESS
    An important problem in spatial statistics is to predict the unobserved value z(s0) at a specified location s0 based on the information of n observations z(sα), α=1, …, n. It can be achieved in three stages of (1) estimating the variograms, (2) fitting a model to the estimated variograms, and (3) applying the so-called ordinary (or universal) kriging. The present article proposes a method to detect influential observations in variogram estimation, variogram model fitting to the estimated variograms, and spatial prediction using the fitted variogram model. To do this, we derive the influence functions for statistics in the above three stages assuming that the underlying process of the observed spatial data is second-order stationary. A real numerical example is analyzed to show the validity or usefulness of the proposed influence functions. Comparison is made with the influence function derived by Gunst and Hartfield (1997).
    Download PDF (2185K)
  • Osamu Sugano
    2000 Volume 13 Issue 1 Pages 41-48
    Published: 2000
    Released on J-STAGE: December 09, 2009
    JOURNAL FREE ACCESS
    The Constellation Graph model (Sugano et al., 1988) and Trigonometric Series transformation model (Sugano, 1994) are proposed by a transformation of the explanatory variable space. However, those models are not linear with respect to parameters. So, the approximate values of the parameters are determined by the use of the Monte Carlo method. In this paper, we determine the parameters by the use of the alternative least square method for the model omitting the restriction of the weights. The model to obtain a predicted value utilizing weighted higher moments is called the Generalized Constellation Graph Transformation Model or GCGTM for short. We describe the method in detail and show some examples of application to air pollution data.
    Download PDF (696K)
  • 2000 Volume 13 Issue 1 Pages 49-53
    Published: 2000
    Released on J-STAGE: December 09, 2009
    JOURNAL FREE ACCESS
    Download PDF (375K)
feedback
Top