9,259 research outputs found
Decomposition numbers for Hecke algebras of type : the -separated case
The paper studies the modular representation theory of the cyclotomic Hecke
algebras of type with (\eps,q)-separated parameters. We show that
the decomposition numbers of these algebras are completely determined by the
decomposition matrices of related cyclotomic Hecke algebras of type ,
where and . Furthermore, the proof gives an explicit
algorithm for computing these decomposition numbers. Consequently, in
principle, the decomposition matrices of these algebras are now known in
characteristic zero. In proving these results, we develop a Specht module
theory for these algebras, explicitly construct their simple modules and
introduce and study analogues of the cyclotomic Schur algebras of type
when the parameters are (\eps,q)-separated. The main results of
the paper rest upon two Morita equivalences: the first reduces the calculation
of all decomposition numbers to the case of the \textit{-splittable
decomposition numbers} and the second Morita equivalence allows us to compute
these decomposition numbers using an analogue of the cyclotomic Schur algebras
for the Hecke algebras of type .Comment: Final versio
Learning Anytime Predictions in Neural Networks via Adaptive Loss Balancing
This work considers the trade-off between accuracy and test-time
computational cost of deep neural networks (DNNs) via \emph{anytime}
predictions from auxiliary predictions. Specifically, we optimize auxiliary
losses jointly in an \emph{adaptive} weighted sum, where the weights are
inversely proportional to average of each loss. Intuitively, this balances the
losses to have the same scale. We demonstrate theoretical considerations that
motivate this approach from multiple viewpoints, including connecting it to
optimizing the geometric mean of the expectation of each loss, an objective
that ignores the scale of losses. Experimentally, the adaptive weights induce
more competitive anytime predictions on multiple recognition data-sets and
models than non-adaptive approaches including weighing all losses equally. In
particular, anytime neural networks (ANNs) can achieve the same accuracy faster
using adaptive weights on a small network than using static constant weights on
a large one. For problems with high performance saturation, we also show a
sequence of exponentially deepening ANNscan achieve near-optimal anytime
results at any budget, at the cost of a const fraction of extra computation
Detection and Diagnosis of Motor Stator Faults using Electric Signals from Variable Speed Drives
Motor current signature analysis has been investigated widely for diagnosing faults of induction motors. However, most of these studies are based on open loop drives. This paper examines the performance of diagnosing motor stator faults under both open and closed loop operation modes. It examines the effectiveness of conventional diagnosis features in both motor current and voltage signals using spectrum analysis. Evaluation results show that the stator fault causes an increase in the sideband amplitude of motor current signature only when the motor is under the open loop control. However, the increase in sidebands can be observed in both the current and voltage signals under the sensorless control mode, showing that it is more promising in diagnosing the stator faults under the sensorless control operation
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