scholarly journals A Generalized Two-Dimensional Index to Measure the Degree of Deviation from Double Symmetry in Square Contingency Tables

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2067
Author(s):  
Shuji Ando ◽  
Hikaru Hoshi ◽  
Aki Ishii ◽  
Sadao Tomizawa
Keyword(s):  
Contingency Tables ◽  
Point Symmetry ◽  
Two Dimensional ◽  
Numerical Examples ◽  
Symmetry Model ◽  
Leibler Information ◽  
Power Divergence ◽  
Double Symmetry ◽  
Special Case

The double symmetry model satisfies both the symmetry and point symmetry models simultaneously. To measure the degree of deviation from the double symmetry model, a two-dimensional index that can concurrently measure the degree of deviation from symmetry and point symmetry is considered. This two-dimensional index is constructed by combining two existing indexes. Although the existing indexes are constructed using power divergence, the existing two-dimensional index that can concurrently measure both symmetries is constructed using only Kullback-Leibler information, which is a special case of power divergence. Previous studies note the importance of using several indexes of divergence to compare the degrees of deviation from a model for several square contingency tables. This study, therefore, proposes a two-dimensional index based on power divergence in order to measure deviation from double symmetry for square contingency tables. Numerical examples show the utility of the proposed two-dimensional index using two datasets.

scholarly journals Marginal Cumulative Logistic Model of General Order for Multi-way Contingency Tables

2020 ◽  
Vol 49 (2) ◽  
pp. 53-61
Author(s):  
Takuya Yoshimoto ◽  
Kouji Tahata ◽  
Sadao Tomizawa
Keyword(s):  
Contingency Table ◽  
Logistic Model ◽  
Contingency Tables ◽  
Symmetry Model ◽  
General Order ◽  
Special Case

For multi-way contingency table, Bhapkar and Darroch (1990) considered the marginal symmetry model for order h. The present paper proposes a marginal cumulative logistic model for order h. When h=1, this model reduces to the marginal logistic model (Agresti, 2002). It also gives a theorem that the marginal symmetry model for order h holds if and only if (i) the marginal cumulative logistic model for order h, (ii) the marginal moment equality model for order h, and (iii) the marginal symmetry model for order h-1 hold. A special case of this theorem with h=1 is identical to the result of Tahata, Katakura and Tomizawa (2007).

scholarly journals Two-Dimensional Index of Departure from the Symmetry Model for Square Contingency Tables with Nominal Categories

Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2031
Author(s):  
Tomotaka Momozaki ◽  
Tomoyuki Nakagawa ◽  
Aki Ishii ◽  
Yusuke Saigusa ◽  
Sadao Tomizawa
Keyword(s):  
Numerical Experiments ◽  
Diversity Index ◽  
Contingency Tables ◽  
Real Data ◽  
The Other ◽  
Two Dimensional ◽  
Measures Of Association ◽  
Log Odds ◽  
Nominal Categories ◽  
Power Divergence

In the analysis of two-way contingency tables, the degree of departure from independence is measured using measures of association between row and column variables (e.g., Yule’s coefficients of association and of colligation, Cramér’s coefficient, and Goodman and Kruskal’s coefficient). On the other hand, in the analysis of square contingency tables with the same row and column classifications, we are interested in measuring the degree of departure from symmetry rather than independence. Over past years, many studies have proposed various types of indexes based on their power divergence (or diversity index) to represent the degree of departure from symmetry. This study proposes a two-dimensional index to measure the degree of departure from symmetry in terms of the log odds of each symmetric cell with respect to the main diagonal of the table. By measuring the degree of departure from symmetry in terms of the log odds of each symmetric cell, the analysis results are easier to interpret than existing indexes. Numerical experiments show the utility of the proposed two-dimensional index. We show the usefulness of the proposed two-dimensional index by using real data.

scholarly journals Collapsed Double Symmetry Model and Its Decomposition for Square Contingency Tables

2016 ◽  
Vol 5 (4) ◽  
pp. 31
Author(s):  
Kouji Yamamoto ◽  
Yuya Matsuda ◽  
Sadao Tomizawa
Keyword(s):  
Contingency Table ◽  
Occupational Mobility ◽  
Contingency Tables ◽  
Square Contingency Table ◽  
Mobility Data ◽  
Symmetry Model ◽  
New Models ◽  
Original Table ◽  
Double Symmetry ◽  
Square Tables

For a square contingency table with ordinal categories, there may be a case that one wants to analyze several collapsed tables obtained by combining some adjacent categories of the original table. This paper proposes some new models which indicate double symmetry, quasi double symmetry and marginal double symmetry for the collapsed square tables. It also gives a decomposition of the double symmetry model for collapsed tables. Two kinds of occupational mobility data are analyzed using new models.

scholarly journals Onset of Convection in Two-Dimensional Porous Cavities with Open and Conducting Boundaries

2021 ◽  
Vol 136 (3) ◽  
pp. 791-812
Author(s):  
Peder A. Tyvand ◽  
Jonas Kristiansen Nøland
Keyword(s):  
Critical Rayleigh Number ◽  
Numerical Results ◽  
Temperature Perturbation ◽  
Two Dimensional ◽  
Onset Of Convection ◽  
Order Problem ◽  
Fourth Order Problem ◽  
Thermally Conducting ◽  
Perturbation Pressure ◽  
Special Case

AbstractThe onset of thermal convection in two-dimensional porous cavities heated from below is studied theoretically. An open (constant-pressure) boundary is assumed, with zero perturbation temperature (thermally conducting). The resulting eigenvalue problem is a full fourth-order problem without degeneracies. Numerical results are presented for rectangular and elliptical cavities, with the circle as a special case. The analytical solution for an upright rectangle confirms the numerical results. Streamlines penetrating the open cavities are plotted, together with the isotherms for the associated closed thermal cells. Isobars forming pressure cells are depicted for the perturbation pressure. The critical Rayleigh number is calculated as a function of geometric parameters, including the tilt angle of the rectangle and ellipse. An improved physical scaling of the Darcy–Bénard problem is suggested. Its significance is indicated by the ratio of maximal vertical velocity to maximal temperature perturbation.

scholarly journals On the Bean critical-state model in superconductivity

1996 ◽  
Vol 7 (3) ◽  
pp. 237-247 ◽  
Author(s):  
L. Prigozhin
Keyword(s):  
Variational Inequalities ◽  
Critical State ◽  
Existence And Uniqueness ◽  
Critical State Model ◽  
Type Ii ◽  
Two Dimensional ◽  
Axially Symmetric ◽  
Uniqueness Of The Solution ◽  
Type Ii Superconductivity ◽  
Special Case

We consider two-dimensional and axially symmetric critical-state problems in type-II superconductivity, and show that these problems are equivalent to evolutionary quasi-variational inequalities. In a special case, where the inequalities become variational, the existence and uniqueness of the solution are proved.

Effects of Curvature on Laminar Boundary Layers in Sink-Type Flows

1969 ◽  
Vol 91 (3) ◽  
pp. 353-358 ◽  
Author(s):  
W. A. Gustafson ◽  
I. Pelech
Keyword(s):  
Boundary Layer ◽  
Boundary Layers ◽  
Momentum Equation ◽  
Similarity Solutions ◽  
Momentum Thickness ◽  
Two Dimensional ◽  
Thickness Increase ◽  
Laminar Boundary Layers ◽  
Converging Channel ◽  
Special Case

The two-dimensional, incompressible laminar boundary layer on a strongly curved wall in a converging channel is investigated for the special case of potential velocity inversely proportional to the distance along the wall. Similarity solutions of the momentum equation are obtained by two different methods and the differences between the methods are discussed. The numerical results show that displacement and momentum thickness increase linearly with curvature while skin friction decreases linearly.

Acceleration Analysis of Platform-Type Manipulators

1996 ◽  
Author(s):  
Maher G. Mohamed
Keyword(s):  
Stewart Platform ◽  
Algebraic Manipulation ◽  
Analysis Procedure ◽  
Compact Form ◽  
Numerical Examples ◽  
Acceleration Field ◽  
Center Point ◽  
Planar Manipulators ◽  
Acceleration Analysis ◽  
Special Case

Abstract The screw algebra is used to efficiently derive expressions in compact form for both the angular accelerations of the moving links and the linear accelerations of points on the links of platform-type manipulators. The analysis employs the property that the acceleration state of the manipulator platform can be determined by considering the acceleration states of the links of only one — any one — of the manipulator legs. The obtained expressions provide an ease in symbolic and algebraic manipulation. The analysis is then extended to specify the acceleration center point of ithe nstantaneous motion of the manipulator platform. The acceleration center point is then used in expressing the distribution of the acceleration field of the platform instant motion which is important in manipulator synthesis. The special case of planar manipulators is studied and simpler expressions are derived. Numerical examples are presented for the analysis of a 3-DOF planar platform-type and of a 6-DOF spatial “Stewart Platform” manipulators to illustrate the analysis procedure.

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