4,264 research outputs found
Regularized Ordinal Regression and the ordinalNet R Package
Regularization techniques such as the lasso (Tibshirani 1996) and elastic net
(Zou and Hastie 2005) can be used to improve regression model coefficient
estimation and prediction accuracy, as well as to perform variable selection.
Ordinal regression models are widely used in applications where the use of
regularization could be beneficial; however, these models are not included in
many popular software packages for regularized regression. We propose a
coordinate descent algorithm to fit a broad class of ordinal regression models
with an elastic net penalty. Furthermore, we demonstrate that each model in
this class generalizes to a more flexible form, for instance to accommodate
unordered categorical data. We introduce an elastic net penalty class that
applies to both model forms. Additionally, this penalty can be used to shrink a
non-ordinal model toward its ordinal counterpart. Finally, we introduce the R
package ordinalNet, which implements the algorithm for this model class
Impartial avoidance games for generating finite groups
We study an impartial avoidance game introduced by Anderson and Harary. The
game is played by two players who alternately select previously unselected
elements of a finite group. The first player who cannot select an element
without making the set of jointly-selected elements into a generating set for
the group loses the game. We develop criteria on the maximal subgroups that
determine the nim-numbers of these games and use our criteria to study our game
for several families of groups, including nilpotent, sporadic, and symmetric
groups.Comment: 14 pages, 4 figures. Revised in response to comments from refere
Impartial avoidance and achievement games for generating symmetric and alternating groups
We study two impartial games introduced by Anderson and Harary. Both games
are played by two players who alternately select previously-unselected elements
of a finite group. The first player who builds a generating set from the
jointly-selected elements wins the first game. The first player who cannot
select an element without building a generating set loses the second game. We
determine the nim-numbers, and therefore the outcomes, of these games for
symmetric and alternating groups.Comment: 12 pages. 2 tables/figures. This work was conducted during the third
author's visit to DIMACS partially enabled through support from the National
Science Foundation under grant number #CCF-1445755. Revised in response to
comments from refere
An Explanation of the Supervisory Model used by Elementary Principal Supervisors in the State of Missouri
The goal for this paper was to discuss the efforts a school district has taken to utilize elementary principal supervisors to build and develop principals’ leadership capacities. The question considered was: (1) How are principals supervised and evaluated in one district? Attempting to answer this question is an important step in operationalizing guiding principles that can be shared with principal supervisors. The discussion included the importance of standards, the modeling of instructional supervision by principal supervisors, the reliance of guiding questions and potential data sources. Additional critical factors included coaching with two-way communication based on a trusting, reflective relationship. As the role of principals’ leadership is elevated to increase the performance of teachers and thus the academic performance of students, principal supervisors should be able to provide principals ownership in their supervision and evaluation, evaluate performance based on standards and indicators, deliver feedback, develop trusting relationships, all by making frequent visits to principals’ schools to further the application of principals’ instructional leadership
Appealability of District Court Orders Granting or Denying Stays of Arbitration under 28 U.S.C. Section 1292(a)(1)
Appealability of District Court Orders Granting or Denying Stays of Arbitration under 28 U.S.C. Section 1292(a)(1)
English Labor Law - The 1984 Trade Union Immunities Act and Its Effect on Unions\u27 Legal Status
Vol. 1 Ch. 4 Revealing Ritual Landscapes at the Hopewell Mound Group
https://ideaexchange.uakron.edu/encountering_hopewell/1003/thumbnail.jp
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