25,210 research outputs found

    Table for estimating parameters of Weibull distribution

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    Table yields best linear invariant /BLI/ estimates for log of reliable life under censored life tests, permitting reliability estimations in failure analysis of items with multiple flaws. These BLI estimates have uniformly smaller expected loss than Gauss-Markov best linear unbiased estimates

    Initial states and decoherence of histories

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    We study decoherence properties of arbitrarily long histories constructed from a fixed projective partition of a finite dimensional Hilbert space. We show that decoherence of such histories for all initial states that are naturally induced by the projective partition implies decoherence for arbitrary initial states. In addition we generalize the simple necessary decoherence condition [Scherer et al., Phys. Lett. A (2004)] for such histories to the case of arbitrary coarse-graining.Comment: 10 page

    Goal accomplishment tracking for automatic supervision of plan execution

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    It is common practice to break down plans into a series of goals or sub-goals in order to facilitate plan execution, thereby only burdening the individual agents responsible for their execution with small, easily achievable objectives at any one time, or providing a simple way of sharing these objectives amongst a group of these agents. Ensuring that plans are executed correctly is an essential part of any team management. To allow proper tracking of an agent's progress through a pre-planned set of goals, it is imperative to keep track of which of these goals have already been accomplished. This centralised approach is essential when the agent is part of a team of humans and/or robots, and goal accomplishment is not always being tracked at a low level. This paper presents a framework for an automated supervision system to keep track of changes in world states so as to chart progress through a pre-planned set of goals. An implementation of this framework on a mobile service robot is presented, and applied in an experiment which demonstrates its feasibility

    Adaptive planning for distributed systems using goal accomplishment tracking

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    Goal accomplishment tracking is the process of monitoring the progress of a task or series of tasks towards completing a goal. Goal accomplishment tracking is used to monitor goal progress in a variety of domains, including workflow processing, teleoperation and industrial manufacturing. Practically, it involves the constant monitoring of task execution, analysis of this data to determine the task progress and notification of interested parties. This information is usually used in a passive way to observe goal progress. However, responding to this information may prevent goal failures. In addition, responding proactively in an opportunistic way can also lead to goals being completed faster. This paper proposes an architecture to support the adaptive planning of tasks for fault tolerance or opportunistic task execution based on goal accomplishment tracking. It argues that dramatically increased performance can be gained by monitoring task execution and altering plans dynamically

    Depletion of Branched-Chain Aminotransferase 2 (BCAT2) Enzyme Impairs Myoblast 3 Survival and Myotube Formation

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    Much is known about the positive effects of branched-chain amino acids (BCAA) in regulating muscle protein metabolism. Comparatively much less is known about the effects of these amino acids and their metabolites in regulating myotube formation. Using cultured myoblasts, we showed that although leucine is required for myotube formation, this requirement is easily met by α-ketoisocaproic acid, the ketoacid of leucine. We then demonstrated increases in the expression of the first two enzymes in the catabolism of the three BCAA, branched-chain amino transferase (BCAT2) and branched-chain α-ketoacid dehydrogenase (BCKD), with ~3× increase in BCKD protein expression (p < .05) during differentiation. Furthermore, depletion of BCAT2 abolished myoblast differentiation, as indicated by reduction in the levels of myosin heavy chain-1, troponin and myogenin. Supplementation of incubation medium with branched-chain α-ketoacids or related metabolites derivable from BCAT2 functions did not rescue the defects. However, co-depletion of BCKD kinase partially rescued the defects. Collectively, our data indicate a requirement for BCAA catabolism during myotube formation and that this requirement for BCAT2 likely goes beyond the need for this enzyme to generate the α-ketoacids of the BCAA.York University Librarie

    Bethe Ansatz for a Quantum Supercoset Sigma Model

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    We study an integrable conformal OSp(2m + 2|2m) supercoset model as an analog to the AdS_5 X S^5 superstring world-sheet theory. Using the known S-matrix for this system, we obtain integral equations for states of large particle density in an SU(2) sector, which are exact in the sigma model coupling constant. As a check, we derive as a limit the general classical Bethe equation of Kazakov, Marshakov, Minahan, and Zarembo. There are two distinct quantum expansions around the well-studied classical limit, the lambda^{-1/2} effects and the 1/J effects. Our approach captures the first type, but not the second.Comment: 30 pages, 1 figure, v2: references adde

    Chaos in an Exact Relativistic 3-body Self-Gravitating System

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    We consider the problem of three body motion for a relativistic one-dimensional self-gravitating system. After describing the canonical decomposition of the action, we find an exact expression for the 3-body Hamiltonian, implicitly determined in terms of the four coordinate and momentum degrees of freedom in the system. Non-relativistically these degrees of freedom can be rewritten in terms of a single particle moving in a two-dimensional hexagonal well. We find the exact relativistic generalization of this potential, along with its post-Newtonian approximation. We then specialize to the equal mass case and numerically solve the equations of motion that follow from the Hamiltonian. Working in hexagonal-well coordinates, we obtaining orbits in both the hexagonal and 3-body representations of the system, and plot the Poincare sections as a function of the relativistic energy parameter η\eta . We find two broad categories of periodic and quasi-periodic motions that we refer to as the annulus and pretzel patterns, as well as a set of chaotic motions that appear in the region of phase-space between these two types. Despite the high degree of non-linearity in the relativistic system, we find that the the global structure of its phase space remains qualitatively the same as its non-relativisitic counterpart for all values of η\eta that we could study. However the relativistic system has a weaker symmetry and so its Poincare section develops an asymmetric distortion that increases with increasing η\eta . For the post-Newtonian system we find that it experiences a KAM breakdown for η≃0.26\eta \simeq 0.26: above which the near integrable regions degenerate into chaos.Comment: latex, 65 pages, 36 figures, high-resolution figures available upon reques
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