Magnetostrictive direct drive motors

Developing magnetostrictive direct drive research motors to power robot joints is discussed. These type motors are expected to produce extraordinary torque density, to be able to perform microradian incremental steps and to be self-braking and safe with the power off. Several types of motor designs have been attempted using magnetostrictive materials. One of the candidate approaches (the magnetostrictive roller drive) is described. The method in which the design will function is described as is the reason why this approach is inherently superior to the other approaches. Following this, the design will be modelled and its expected performance predicted. This particular candidate design is currently undergoing detailed engineering with prototype construction and testing scheduled for mid 1991

Searches for CP Violation in charm at LHCb

LHCb has collected the world's largest sample of charmed hadrons. This sample is used to search for direct and indirect CP Violation in charm. Recent and updated measurements from several decay modes are presented.Comment: To be published in the proceedings of CHARM-2015, Detroit, MI, 18-22 May 201

Computation of Lickorish's Three Manifold Invariants using Chern-Simons Theory

It is well known that any three-manifold can be obtained by surgery on a framed link in $S^3$. Lickorish gave an elementary proof for the existence of the three-manifold invariants of Witten using a framed link description of the manifold and the formalisation of the bracket polynomial as the Temperley-Lieb Algebra. Kaul determined three-manifold invariants from link polynomials in SU(2) Chern-Simons theory. Lickorish's formula for the invariant involves computation of bracket polynomials of several cables of the link. We describe an easier way of obtaining the bracket polynomial of a cable using representation theory of composite braiding in SU(2) Chern-Simons theory. We prove that the cabling corresponds to taking tensor products of fundamental representations of SU(2). This enables us to verify that the two apparently distinct three-manifold invariants are equivalent for a specific relation of the polynomial variables.Comment: 25 pages, 11 eps figures, harvmac file (big mode

X-ray properties of the microquasar GRS 1915+105 during a variability class transition

We present a detailed X-ray study of the microquasar GRS 1915+105 during a variability class transition observed in 2000 June with the PPCs of the Indian X-ray Astronomy Experiment. We supplement this observation with data from the RXTE archives. The source made a transition from a steady low-hard state to a regular oscillatory behaviour in the light curve known as bursts or class `rho' (Belloni et al. 2000) between 2000 May 11 and 17 and reverted back to the low-hard state on 2000 June 27. A gradual change in the burst recurrence time from about 75 s to about 40 s was observed which then increased to about 120 s during the ~ 40 days of class `rho'. The regular bursts disappeared from the X-ray light curves and the class transition was observed to occur within 1.5 hours on 2000 June 27 with the PPCs. A correlation is found between the observed QPO frequency at 5-8 Hz in the quiescent phase and the average X-ray intensity of the source during the class `rho'. We notice a strong similarity between the properties of the source during the class `rho' and those during the oscillatory phase of the observations of class `alpha'. From the timing and spectral analysis, it is found that the observed properties of the source over tens of days during the class `rho' are identical to those over a time scale of a few hundreds of seconds in the class `alpha'. Examining the light curves from the beginning of the RXTE/PCA and RXTE/ASM observations, it is found that the change of state from radio-quiet low-hard state to high state occurs through the X-ray classes `rho' and `alpha' which appear together during the state transition. It is further inferred that the source switches from low-hard state to the class `rho' through the intermediate class `alpha'.Comment: 10 pages with 9 figures, LaTex. To be appeared in MNRA

Time-Series Models in Marketing

Marketing data appear in a variety of forms. An often-seen form is time-series data, like sales per month, prices over the last few years, market shares per week. Time-series data can be summarized in time-series models. In this chapter we review a few of these, focusing in particular on domains that have received considerable attention in the marketing literature. These are (1) the use of persistence modelling and (2) the use of state space models.Marketing;Persistence;State Space;Time Series