Hierarchically Clustered Adaptive Quantization CMAC and Its Learning Convergence

No abstract availabl

Design and Implementation of an RNS-based 2D DWT Processor

No abstract availabl

On the Implementation of Efficient Channel Filters for Wideband Receivers by Optimizing Common Subexpression Elimination Methods

No abstract availabl

Gaussian Process Model Predictive Control of An Unmanned Quadrotor

The Model Predictive Control (MPC) trajectory tracking problem of an unmanned quadrotor with input and output constraints is addressed. In this article, the dynamic models of the quadrotor are obtained purely from operational data in the form of probabilistic Gaussian Process (GP) models. This is different from conventional models obtained through Newtonian analysis. A hierarchical control scheme is used to handle the trajectory tracking problem with the translational subsystem in the outer loop and the rotational subsystem in the inner loop. Constrained GP based MPC are formulated separately for both subsystems. The resulting MPC problems are typically nonlinear and non-convex. We derived 15 a GP based local dynamical model that allows these optimization problems to be relaxed to convex ones which can be efficiently solved with a simple active-set algorithm. The performance of the proposed approach is compared with an existing unconstrained Nonlinear Model Predictive Control (NMPC). Simulation results show that the two approaches exhibit similar trajectory tracking performance. However, our approach has the advantage of incorporating constraints on the control inputs. In addition, our approach only requires 20% of the computational time for NMPC.Comment: arXiv admin note: text overlap with arXiv:1612.0121

Improved Memoryless RNS Forward Converter Based on the Periodicity of Residues

The residue number system (RNS) is suitable for DSP architectures because of its ability to perform fast carry-free arithmetic. However, this advantage is over-shadowed by the complexity involved in the conversion of numbers between binary and RNS representations. Although the reverse conversion (RNS to binary) is more complex, the forward transformation is not simple either. Most forward converters make use of look-up tables (memory). Recently, a memoryless forward converter architecture for arbitrary moduli sets was proposed by Premkumar in 2002. In this paper, we present an extension to that architecture which results in 44% less hardware for parallel conversion and achieves 43% improvement in speed for serial conversions. It makes use of the periodicity properties of residues obtained using modular exponentiation

Better Care at Less Cost Without Miracles

Our present system of medical care is not a system at all. The majority of physicians, operating alone as private entrepreneurs, constitute an army of pushcart vendors in an age of supermarkets. Most patients pay by the cumbersome fee-for-service or piecework method, which involves separate billing for visits to doctors, shots, x-rays, laboratory tests, surgery, anesthesia, hospital room and board, etc., etc. The American hospital system, as Herman M. and Anne R. Somers of Princeton University said in their book, Medicare and the Hospitals, is largely a figure of speech, the result of a haphazard growth of isolated, uncoordinated institutions

A Critical Analysis of the Rose-Weaver Measurement Technique for BSF Silicon Solar Cells

The design of the optimal efficiency silicon solar cell requires the minimization of several performance-limiting phenomena. In particular, much improvement is necessary to decrease the loss of minority carriers to recombination. Thus, in order to focus our design efforts in the development of an optimal efficiency solar cell it is imperative that we be able to experimentally distinguish and assign values to the different forms of minority carrier recombination in the cell. Recently, B. H. Rose and H. T. Weaver of Sandia National Laboratories have proposed a method to evaluate minority carrier recombination in the back surface field (BSF) solar cell through measurement of the short circuit current and open circuit voltage decay fates. In this thesis, we critically analyze the Rose-Weaver Method. In particular, we investigate the mathematical model formulated by Rose and Weaver to describe the decay of the short circuit current and the open circuit voltage. A study of the model equations reveals that, for even small fluctuations in the experimental measurements, a large variation in the model solutions occurs. Moreover, the solution of the model is shown to rely on extremely accurate (perhaps unobtainably accurate) knowledge of material parameters. To avoid dependence on material parameters, we analyze a second experiment in which the back surface field of the solar cell is removed. However, the model which results from combining this experiment with the original experiment shows an even greater variation of the model solutions to uncertainty in the experimental measurements. In summary, unless we make extremely precise measurements and avoid dependence on imprecisely known material parameters, particularly, n;, the Rose-Weaver Method can lead to radically different descriptions of minority carrier recombination in the solar cell

Administration of promotion in the three-year junior high school

Thesis (Ed.M.)--Boston Universit