6,877 research outputs found
Integrating Learning from Examples into the Search for Diagnostic Policies
This paper studies the problem of learning diagnostic policies from training
examples. A diagnostic policy is a complete description of the decision-making
actions of a diagnostician (i.e., tests followed by a diagnostic decision) for
all possible combinations of test results. An optimal diagnostic policy is one
that minimizes the expected total cost, which is the sum of measurement costs
and misdiagnosis costs. In most diagnostic settings, there is a tradeoff
between these two kinds of costs. This paper formalizes diagnostic decision
making as a Markov Decision Process (MDP). The paper introduces a new family of
systematic search algorithms based on the AO* algorithm to solve this MDP. To
make AO* efficient, the paper describes an admissible heuristic that enables
AO* to prune large parts of the search space. The paper also introduces several
greedy algorithms including some improvements over previously-published
methods. The paper then addresses the question of learning diagnostic policies
from examples. When the probabilities of diseases and test results are computed
from training data, there is a great danger of overfitting. To reduce
overfitting, regularizers are integrated into the search algorithms. Finally,
the paper compares the proposed methods on five benchmark diagnostic data sets.
The studies show that in most cases the systematic search methods produce
better diagnostic policies than the greedy methods. In addition, the studies
show that for training sets of realistic size, the systematic search algorithms
are practical on todays desktop computers
PuLSE-I: Deriving instances from a product line infrastructure
Reusing assets during application engineering promises to improve the efficiency of systems development. However, in order to benefit from reusable assets, application engineering processes must incorporate when and how to use the reusable assets during single system development. However, when and how to use a reusable asset depends on what types of reusable assets have been created.Product line engineering approaches produce a reusable infrastructure for a set of products. In this paper, we present the application engineering process associated with the PuLSE product line software engineering method - PuLSE-I. PuLSE-I details how single systems can be built efficiently from the reusable product line infrastructure built during the other PuLSE activities
Living Lives of Faith (Holiness)
In lieu of an abstract, below is the essay\u27s first paragraph.
Each year on November 1st, The Roman Catholic Church celebrates the Feast of All Saints and encourages us to reflect on men and women of all ages who are models of holiness and heroes in the faith
Review of Student Performance in Developmental mathematics Courses Taught at Virginia Western Community College
The problem of this study was to determine changes that should be made by Virginia Western mathematics faculty to improve developmental mathematics instruction
Derived automorphism groups of K3 surfaces of Picard rank 1
We give a complete description of the group of exact autoequivalences of the bounded derived category of coherent sheaves on a K3 surface of Picard rank 1. We do this by proving that a distinguished connected component of the space of stability conditions is preserved by all autoequivalences, and is contractible
Engineering of spin-lattice relaxation dynamics by digital growth of diluted magnetic semiconductor CdMnTe
The technological concept of "digital alloying" offered by molecular-beam
epitaxy is demonstrated to be a very effective tool for tailoring static and
dynamic magnetic properties of diluted magnetic semiconductors. Compared to
common "disordered alloys" with the same Mn concentration, the spin-lattice
relaxation dynamics of magnetic Mn ions has been accelerated by an order of
magnitude in (Cd,Mn)Te digital alloys, without any noticeable change in the
giant Zeeman spin splitting of excitonic states, i.e. without effect on the
static magnetization. The strong sensitivity of the magnetization dynamics to
clustering of the Mn ions opens a new degree of freedom for spin engineering.Comment: 9 pages, 3 figure
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