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Dissipative quantum theory: Implications for quantum entanglement
Three inter-related topics are discussed here. One, the Lindblad dynamics of
quantum dissipative systems; two, quantum entanglement in composite systems and
its quantification based on the Tsallis entropy; and three, robustness of
entanglement under dissipation. After a brief review of the Lindblad theory of
quantum dissipative systems and the idea of quantum entanglement in composite
quantum systems illustrated by describing the three particle systems, the
behavior of entanglement under the influence of dissipative processes is
discussed. These issues are of importance in the discussion of quantum
nanometric systems of current research.Comment: 12 pages, 1 Tabl
Rerepresenting and Restructuring Domain Theories: A Constructive Induction Approach
Theory revision integrates inductive learning and background knowledge by
combining training examples with a coarse domain theory to produce a more
accurate theory. There are two challenges that theory revision and other
theory-guided systems face. First, a representation language appropriate for
the initial theory may be inappropriate for an improved theory. While the
original representation may concisely express the initial theory, a more
accurate theory forced to use that same representation may be bulky,
cumbersome, and difficult to reach. Second, a theory structure suitable for a
coarse domain theory may be insufficient for a fine-tuned theory. Systems that
produce only small, local changes to a theory have limited value for
accomplishing complex structural alterations that may be required.
Consequently, advanced theory-guided learning systems require flexible
representation and flexible structure. An analysis of various theory revision
systems and theory-guided learning systems reveals specific strengths and
weaknesses in terms of these two desired properties. Designed to capture the
underlying qualities of each system, a new system uses theory-guided
constructive induction. Experiments in three domains show improvement over
previous theory-guided systems. This leads to a study of the behavior,
limitations, and potential of theory-guided constructive induction.Comment: See http://www.jair.org/ for an online appendix and other files
accompanying this articl
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