Papers.

Exact real arithmetic using Möbius transformations

Efficient on-line computation of real functions using exact floating point

Easy access via a TTS website to mono- and multilingual text-to-speech systems

Designing XML Internet Applications

Creating a Thesaurus from Text: A “Bottom-Up” Approach to Organizing Medical Knowledge

Clustering Methods for Collaborative Filtering

Grouping people into clusters based on the items they have purchased allows accurate recommendations of new items for purchase: if you and I have liked many of the same movies, then I will probably enjoy other movies that you like. Recommending items based on similarity of interest (a.k.a. collaborative filtering) is attractive for many domains: books, CDs, movies, etc., but does not always work well. Because data are always sparse- any given person has seen only a small fraction of all movies- much more accurate predictions can be made by grouping people into clusters with similar movies and grouping movies into clusters which tend to be liked by the same people. Finding optimal clusters is tricky because the movie groups should be used to help determine the people groups and visa versa. We present a formal statistical model of collaborative filtering, and compare different algorithms for estimating the model parameters including variations of K-means clustering and Gibbs Sampling. This formal model is easily extended to handle clustering of objects with multiple attributes.

Bayesian Q-Learning

Analysis of linear hashing revisited

An evaluation of UMLS as a controlled terminology for the Problem List Toolkit

An Enterprise “Problem Picker” for Capturing Clinical Problem Data

Algorithms for exact real arithmetic using Möbius transformations

A "lexically-suggested logical closure" metric for medical terminology maturity

A Lazy Model-Based Approach to On-Line Classification

A Java-Based Tool for Entry of a Medical Problem List, Which Accesses a Remote Large-Scale Enterprise Vocabulary Server

A Java-Based Interface for Medical Research Project Classification Using Metaphrase

Space Optimizations for Total Ranking

Optical measurements to characterize a dc-arcjet plasma during diamond CVD

Fourth South American Workshop on String Processing (WSP 1997)

Absolute concentration measurements of CH radicals in a diamond-depositing dc-arcjet reactor

Practical Parallel Programming, by Gregory V. Wilson

Doing your first OO project: OO education issues in industry and academia

A first step to formally evaluate collaborative work

Block addressing indices for approximate text retrieval

The Mercury Interconnect Architecture: A Cost-effective Infrastructure for High-performance Servers

LDC online

Proximal nodes

Building a Scaleable Geo-Spatial DBMS: Technology, Implementation, and Evaluation

Medical Informatics Challenges of the 1990s: Acknowledging Secular Change

A visual programming interface for Smalltalk

Semantics of exact real arithmetic

In this paper, we incorporate a representation of the non-negative extended real numbers based on the composition of linear fractional transformations with non-negative integer coefficients into the Programming Language for Computable Functions (PCF) with products. We present two models for the extended language and show that they are computationally adequate with respect to the operational semantics.

Using scoping rules as a distributed coordination language

ThreadMon: A Tool for Monitoring Multithreaded Program Performance

Distributed Processing: Requirements for an Object-Oriented Approach

Spatial density distributions of C2, C3, and CH radicals by laser-induced fluorescence in a diamond depositing dc-arcjet

Atomic hydrogen concentration in a diamond depositing dc arcjet determined by calorimetry

Adaptive Probabilistic Networks with Hidden Variables

A new representation for exact real numbers

We develop the theoretical foundation of a new representation of real numbers based on the infinite composition of linear fractional transformations (lft), equivalently the infinite product of matrices, with non-negative coefficients. Any rational interval in the one point compactification of the real line, represented by the unit circle S1, is expressed as the image of the base interval [0, ∞] under an lft. A sequence of shrinking nested intervals is then represented by an infinite product of matrices with integer coefficients such that the first so-called sign matrix determines an interval on which the real number lies.

Minkowski Functional Description of Microwave Background Gaussianity

A Gaussian distribution of cosmic microwave background temperature fluctuations is a generic prediction of inflation. Upcoming high-resolution maps of the microwave background will allow detailed tests of Gaussianity down to small angular scales, providing a crucial test of inflation. We propose Minkowski functionals as a calculational tool for testing Gaussianity and characterizing deviations from it. We review the mathematical formalism of Minkowski functionals of random fields; for Gaussian fields the functionals can be calculated exactly. We then apply the results to pixelized maps, giving explicit expressions for calculating the functionals from maps as well as the Gaussian predictions, including corrections for map boundaries, pixel noise, and pixel size and shape. Variances of the functionals for Gaussian distributions are derived in terms of the map correlation function. Applications to microwave background maps are discussed.

Preface

Estimating from outputs of oversampled delta-sigma modulation

Hybrid algorithms for digital halftoning and their application to medical imaging

Performance of phase-based algorithms for disparity estimation

Relevance Feedback and Query Expansion for Searching the Web: A Model for Searching a Digital Library

Peak Loads and Postal Services: Some Implications of Multi-Stage Production

Multiple approximate string matching

Nonuniform Dynamic Discretization in Hybrid Networks

Image Segmentation in Video Sequences: A Probabilistic Approach

"Background subtraction" is an old technique for finding moving objects in a video sequence--for example, cars driving on a freeway. The idea is that subtracting the current image from a time-averaged background image will leave only nonstationary objects. It is, however, a crude approximation to the task of classifying each pixel of the current image; it fails with slow-moving objects and does not distinguish shadows from moving objects. The basic idea of this paper is that we can classify each pixel using a model of how that pixel looks when it is part of different classes. We learn a mixture-of-Gaussians classification model for each pixel using an unsupervised technique--an efficient, incremental version of EM. Unlike the standard image-averaging approach, this automatically updates the mixture component for each class according to likelihood of membership; hence slow-moving objects are handled perfectly. Our approach also identifies and eliminates shadows much more effectively than other techniques such as thresholding. Application of this method as part of the Roadwatch traffic surveillance project is expected to result in significant improvements in vehicle identification and tracking.

Type classes: an exploration of the design space

When type classes were first introduced in Haskell they were regarded as a fairly experimental language feature, and therefore warranted a fairly conservative design. Since that time, practical experience has convinced many programmers of the benefits and convenience of type classes. However, on occasion, these same programmers have discovered examples where seemingly natural applications for type class overloading are prevented by the restrictions imposed by the Haskell design. It is possible to extend the type class mechanism of Haskell in various ways to overcome these limitations, but such proposals must be designed with great care. For example, several different extensions have been implemented in Gofer. Some of these, particularly the support for multi-parameter classes, have proved to be very useful, but interactions between other aspects of the design have resulted in a type system that is both unsound and undecidable. Another illustration is the introduction of constructor cla...

The situation calculus and Hehner's programming theory, harmonization through reification

Supporting Postcoordination in an Electronic Problem List