Design optimization of a slotless PM brushless motor with spiral wound laminations for rim driven thrusters

This paper discusses the analysis and design of a very thin slotless PM brushless motor whose stator laminations are manufactured from a single strip of steel that is edge wound into a spiral (like a “Slinky”) and then fitted over the windings that are preformed on the outside surface of a non-conducting former. Analytical and finite element analysis (FEA) are used to determine the constrained optimum dimensions of a motor used to drive a rim driven thruster in which the motor rotor is fitted onto the rim of the propeller and the stator is encapsulated in the thin Kort nozzle of the thruster. The paper describes the fabrication of a demonstrator motor and presents experimental results to validate the theoretical calculations. Experimental motor performance esults are also reported and compared with those of a slotted motor that fits within the same active radial dimensions as the slotless motor. The slotless motor, which has longer active length and endwindings, and thicker magnets than the slotted motor, was found to be less efficient and more expensive (prototype cost) than the slotted machine

A survey of boat-based recreational fishing in inner Shark Bay 2016/17

Monitoring the temporal and spatial variability in recreational fishing provides necessary information for assessing resource sustainability, monitoring resource allocation and informing fisheries management. This is particularly important in inner Shark Bay because recreational fishing occurs in a World Heritage Area and Marine Park. The majority of boat-based recreational fishers in inner Shark Bay target Pink Snapper (Chrysophrys auratus) and three genetically distinct stocks of this species occur in the Denham Sound, Eastern Gulf and Freycinet Estuary Management Zones

State-wide survey of boat-based recreational fishing in Western Australia 2013/14

Based on the outcomes of an international workshop on recreational fishing survey methods in 2010, the Department of Fisheries developed an integrated survey involving several methods to provide a robust and cost-effective approach for obtaining annual estimates of recreational catch by boat-based fishers at both state-wide and bioregional levels

A Neural Networks Committee for the Contextual Bandit Problem

This paper presents a new contextual bandit algorithm, NeuralBandit, which does not need hypothesis on stationarity of contexts and rewards. Several neural networks are trained to modelize the value of rewards knowing the context. Two variants, based on multi-experts approach, are proposed to choose online the parameters of multi-layer perceptrons. The proposed algorithms are successfully tested on a large dataset with and without stationarity of rewards.Comment: 21st International Conference on Neural Information Processin

Approximate solution of the Duffin-Kemmer-Petiau equation for a vector Yukawa potential with arbitrary total angular momenta

The usual approximation scheme is used to study the solution of the Duffin-Kemmer-Petiau (DKP) equation for a vector Yukawa potential in the framework of the parametric Nikiforov-Uvarov (NU) method. The approximate energy eigenvalue equation and the corresponding wave function spinor components are calculated for arbitrary total angular momentum in closed form. Further, the approximate energy equation and wave function spinor components are also given for case. A set of parameter values is used to obtain the numerical values for the energy states with various values of quantum levelsComment: 17 pages; Communications in Theoretical Physics (2012). arXiv admin note: substantial text overlap with arXiv:1205.0938, and with arXiv:quant-ph/0410159 by other author

Approximate k-state solutions to the Dirac-Yukawa problem based on the spin and pseudospin symmetry

Using an approximation scheme to deal with the centrifugal (pseudo-centrifugal) term, we solve the Dirac equation with the screened Coulomb (Yukawa) potential for any arbitrary spin-orbit quantum number {\kappa}. Based on the spin and pseudospin symmetry, analytic bound state energy spectrum formulas and their corresponding upper- and lower-spinor components of two Dirac particles are obtained using a shortcut of the Nikiforov-Uvarov method. We find a wide range of permissible values for the spin symmetry constant C_{s} from the valence energy spectrum of particle and also for pseudospin symmetry constant C_{ps} from the hole energy spectrum of antiparticle. Further, we show that the present potential interaction becomes less (more) attractive for a long (short) range screening parameter {\alpha}. To remove the degeneracies in energy levels we consider the spin and pseudospin solution of Dirac equation for Yukawa potential plus a centrifugal-like term. A few special cases such as the exact spin (pseudospin) symmetry Dirac-Yukawa, the Yukawa plus centrifugal-like potentials, the limit when {\alpha} becomes zero (Coulomb potential field) and the non-relativistic limit of our solution are studied. The nonrelativistic solutions are compared with those obtained by other methods.Comment: 21 pages, 6 figure

Analytical Treatment of the Oscillating Yukawa Potential

Using a suitable Laguerre basis set that ensures a tridiagonal matrix representation of the reference Hamiltonian, we were able to evaluate in closed form the matrix elements of the generalized Yukawa potential with complex screening parameter. This enabled us to treat analytically both the cosine and sine-like Yukawa potentials on equal footing and compute their bound states spectrum as the eigenvalues of the associated analytical matrix representing their Hamiltonians. Finally we used a carefully designed complex scaling method to evaluate the resonance energies and compared our results satisfactorily with those obtained in the literature.Comment: 8 pages 2 table

Statewide survey of boat-based recreational fishing in Western Australia 2015/16

The statewide survey of boat-based recreational fishing includes three components: (i) off-site Phone Surveys (encompassing an initial Screening Survey, a longitudinal Phone-Diary Survey, and Post-Enumeration Surveys); (ii) on-site Boat Ramp Surveys; and (iii) a Remote Camera Survey

Statewide survey of boat-based recreational fishing in Western Australia 2017/18

The statewide survey of boat-based recreational fishing includes three components: (i) off-site Phone Surveys (encompassing an initial Screening Survey, a longitudinal Phone-Diary Survey, and Post-Enumeration Surveys); (ii) on-site Boat Ramp Surveys; and (iii) Remote Camera Surveys. The main data collection period was the 12-months from September 2017 to August 2018 inclusive, with the Post-Enumeration Surveys occurring from September to December 2018