46 research outputs found
On-line PID tuning for engine idle-speed control using continuous action reinforcement learning automata
PID systems are widely used to apply control without the need to obtain a dynamic model. However, the
performance of controllers designed using standard on-line tuning methods, such as Ziegler-Nichols, can often be
significantly improved. In this paper the tuning process is automated through the use of continuous action
reinforcement learning automata (CARLA). These are used to simultaneously tune the parameters of a three term
controller on-line to minimise a performance objective. Here the method is demonstrated in the context of engine
idle speed control; the algorithm is first applied in simulation on a nominal engine model, and this is followed by
a practical study using a Ford Zetec engine in a test cell. The CARLA provides marked performance benefits
over a comparable Ziegler-Nichols tuned controller in this application
Reversible stretching of homopolymers and random heteropolymers
We have analyzed the equilibrium response of chain molecules to stretching.
For a homogeneous sequence of monomers, the induced transition from compact
globule to extended coil below the -temperature is predicted to be
sharp. For random sequences, however, the transition may be smoothed by a
prevalence of necklace-like structures, in which globular regions and coil
regions coexist in a single chain. As we show in the context of a random
copolymer, preferential solvation of one monomer type lends stability to such
structures. The range of stretching forces over which necklaces are stable is
sensitive to chain length as well as sequence statistics.Comment: 14 pages, 4 figure
Ultra-red Galaxies Signpost Candidate Protoclusters at High Redshift
We present images obtained with LABOCA of a sample of 22 galaxies selected via their red Herschel SPIRE colors. We aim to see if these luminous, rare, and distant galaxies are signposting dense regions in the early universe. Our 870 ÎŒm survey covers an area of â1 deg2 down to an average rms of , with our five deepest maps going â2Ă deeper still. We catalog 86 dusty star-forming galaxies (DSFGs) around our "signposts," detected above a significance of 3.5Ï. This implies a overdensity of (or {L}_{\mathrm{FIR}}=6.7\times {10}^{12}\mbox{--}2.9\times {10}^{13}\,{L}_{\odot }) DSFGs, excluding our signposts, when comparing our number counts to those in "blank fields." Thus, we are 99.93% confident that our signposts are pinpointing overdense regions in the universe, and â95% [50%] confident that these regions are overdense by a factor of at least â„1.5 Ă [2Ă]. Using template spectral energy distributions (SEDs) and SPIRE/LABOCA photometry, we derive a median photometric redshift of z = 3.2 ± 0.2 for our signposts, with an inter-quartile range of z = 2.8â3.6, somewhat higher than expected for ~850 ÎŒm selected galaxies. We constrain the DSFGs that are likely responsible for this overdensity to within of their respective signposts. These "associated" DSFGs are radially distributed within (physical) distances of 1.6 ± 0.5 Mpc from their signposts, have median star formation rates (SFRs) of (for a Salpeter stellar inital mass function) and median gas reservoirs of . These candidate protoclusters have average total SFRs of at least and space densities of ~9 Ă 10â7 Mpcâ3, consistent with the idea that their constituents may evolve to become massive early-type galaxies in the centers of the rich galaxy clusters we see today
Chronic lymphocytic leukaemia Australasian consensus practice statement
Chronic lymphocytic leukaemia (CLL) is the most common haematological malignancy in Australia and New Zealand (ANZ). Considerable changes to diagnostic and management algorithms have occurred within the last decade. The availability of next-generation sequencing and measurable residual disease assessment by flow cytometry allow for advanced prognostication and response assessments. Novel therapies, including inhibitors of Bruton's tyrosine kinase (BTKi) and B-cell lymphoma 2 (BCL2) inhibitors, have transformed the treatment landscape for both treatment-naĂŻve and relapsed/refractory disease, particularly for patients with high-risk genetic aberrations. Recommendations regarding appropriate supportive management continue to evolve, and special considerations are required for patients with CLL with respect to the global SARS-CoV-2 pandemic. The unique funding and treatment environments in Australasia highlight the need for specific local guidance with respect to the investigation and management of CLL. This consensus practice statement was developed by a broadly representative group of ANZ experts in CLL with endorsement by peak haematology bodies, with a view to providing this standardised guidance
Positive-strand RNA virusesâa Keystone Symposia report
Positive-strand RNA viruses have been the cause of several recent outbreaks and epidemics, including the Zika virus epidemic in 2015, the SARS outbreak in 2003, and the ongoing SARS-CoV-2 pandemic. On June 18â22, 2022, researchers focusing on positive-strand RNA viruses met for the Keystone Symposium âPositive-Strand RNA Virusesâ to share the latest research in molecular and cell biology, virology, immunology, vaccinology, and antiviral drug development. This report presents concise summaries of the scientific discussions at the symposium