Cached Sufficient Statistics for Efficient Machine Learning with Large Datasets

This paper introduces new algorithms and data structures for quick counting for machine learning datasets. We focus on the counting task of constructing contingency tables, but our approach is also applicable to counting the number of records in a dataset that match conjunctive queries. Subject to certain assumptions, the costs of these operations can be shown to be independent of the number of records in the dataset and loglinear in the number of non-zero entries in the contingency table. We provide a very sparse data structure, the ADtree, to minimize memory use. We provide analytical worst-case bounds for this structure for several models of data distribution. We empirically demonstrate that tractably-sized data structures can be produced for large real-world datasets by (a) using a sparse tree structure that never allocates memory for counts of zero, (b) never allocating memory for counts that can be deduced from other counts, and (c) not bothering to expand the tree fully near its leaves. We show how the ADtree can be used to accelerate Bayes net structure finding algorithms, rule learning algorithms, and feature selection algorithms, and we provide a number of empirical results comparing ADtree methods against traditional direct counting approaches. We also discuss the possible uses of ADtrees in other machine learning methods, and discuss the merits of ADtrees in comparison with alternative representations such as kd-trees, R-trees and Frequent Sets.Comment: See http://www.jair.org/ for any accompanying file

Conservation laws in the quantum Hall Liouvillian theory and its generalizations

It is known that the localization length scaling of noninteracting electrons near the quantum Hall plateau transition can be described in a theory of the bosonic density operators, with no reference to the underlying fermions. The resulting ``Liouvillian'' theory has a $U(1|1)$ global supersymmetry as well as a hierarchy of geometric conservation laws related to the noncommutative geometry of the lowest Landau level (LLL). Approximations to the Liouvillian theory contain quite different physics from standard approximations to the underlying fermionic theory. Mean-field and large-N generalizations of the Liouvillian are shown to describe problems of noninteracting bosons that enlarge the $U(1|1)$ supersymmetry to $U(1|1) \times SO(N)$ or $U(1|1) \times SU(N)$. These noninteracting bosonic problems are studied numerically for $2 \leq N \leq 8$ by Monte Carlo simulation and compared to the original N=1 Liouvillian theory. The $N>1$ generalizations preserve the first two of the hierarchy of geometric conservation laws, leading to logarithmic corrections at order 1/N to the diffusive large-N limit, but do not preserve the remaining conservation laws. The emergence of nontrivial scaling at the plateau transition, in the Liouvillian approach, is shown to depend sensitively on the unusual geometry of Landau levels.Comment: 13 page

ACTIVITIES OF NURSE PRACTITIONERS AS IDENTIFIED BY MEDICAL DIRECTORS OF UNIVERSITY STUDENT HEALTH SERVICES

University health services play a very important role in the general health, performance, and well-being of the students, the university itself, and the community. As stated by the American College Health Association, the goal of a university health service is to promote and maintain those conditions which will permit and encourage each individual to realize optimum physical, emotional, intellectual, and social well-being. University students have special health care needs such as drug and alcohol abuses, emotional problems, and gynecological, sexual, and contraceptive problems. It is the goal of the health professionals involved with students to meet those needs. Because of these special health care needs, the increasing number of university students, and the present problems associated with medical care and medical distribution, nurse practitioners have become involved in some university percent of these nurse practitioners are in college health services.3 It was believed by the investigators of this study that nurse practitioners could play a special role in this area of health care. As student health medical directors are key persons in defining nurse practitioner activities, the purpose of this study was to determine the activities the directors identified as appropriate for nurse practitioners to perform in a university health care setting. The type of activities identified by them may be crucial in the decision to utilize nurse practitioners in the university student health setting

Stringy Symmetries and Their High-energy Limits

We derive stringy symmetries with conserved charges of arbitrarily high spins from the decoupling of two types of zero-norm states in the old covariant first quantized (OCFQ) spectrum of open bosonic string. These symmetries are valid to all energy and all loop orders in string perturbation theory. The high-energy limit of these stringy symmetries can then be used to fix the proportionality constants between scattering amplitudes of different string states algebraically without referring to Gross and Mende's saddle point calculation of high-energy string-loop amplitudes. These proportionality constants are, as conjectured by Gross, independent of the scattering angle and the order of string perturbation theory. However, we also discover some new nonzero components of high-energy amplitudes not found previously by Gross and Manes. These components are essential to preserve massive gauge invariances or decouple massive zero-norm states of string theory. A set of massive scattering amplitudes and their high energy limit are calculated explicitly to justify our results.Comment: 10 pages. A corrected version of hep-th/0303012. Final version to appear in Phys. Lett.

Zero-norm states and High-energy Symmetries of String Theory

We derive stringy Ward identities from the decoupling of two types of zero-norm states in the old covariant first quantized (OCFQ) spectrum of open bosonic string. These Ward identities are valid to all energy and all loop orders in string perturbation theory. The high-energy limit of these stringy Ward identities can then be used to fix the proportionality constants between scattering amplitudes of different string states algebraically without referring to Gross and Mende's saddle point calculation of high-energy string-loop amplitudes. As examples, all Ward identities for the mass level 4 and 6 are derived, their high-energy limits are calculated and the proportionality constants between scattering amplitudes of different string states are determined. In addition to those identified before, we discover some new nonzero components of high-energy amplitudes not found previously by Gross and Manes. These components are essential to preserve massive gauge invariances or decouple massive zero-norm states of string theory. A set of massive scattering amplitudes and their high energy limits are calculated explicitly for each mass level to justify our results

Growing intimate privatepublics: Everyday utopia in the naturecultures of a young lesbian and bisexual women’s allotment

The Young Women’s Group in Manchester is a ‘young women’s peer health project, run by and for young lesbian and bisexual women’, which runs an allotment as one of its activities. At a time when interest in allotments and gardening appears to be on the increase, the existence of yet another community allotment may seem unremarkable. Yet we suggest that this queer allotment poses challenges for conventional theorisations of allotments, as well as for understandings of public and private. In this article we explore how the allotment project might be understood to be intensely engaged in ‘growing intimate publics’, or what we term ‘privatepublics’. These are paradoxical intimacies, privatepublic spaces which are not necessarily made possible in the usual private sphere of domestic homes. Here we focus on the work involved in materialising the allotment, which we understand as a queer privatepublic ‘natureculture’ (Haraway, 2008) which appears as an ‘everyday utopia’ (Cooper, 2014)

Coherent State Quantization of SU(N) Non-Abelian Chern-Simons Particles

We present a new method of formulating the classical theory of $SU(N+1)$ non-Abelian Chern-Simons (NACS) particles for arbitrary $N\geq 1$ using the symplectic reduction of $CP(N)$ manifold from $S^{2N+1}$. Quantizing the theory using BRST formulation and coherent state path integral method , we obtain a quantum mechanical model for $SU(N+1)$ NACS particles.Comment: 13 pages, Latex File, SNUTP-93-4