2,897 research outputs found
Three Song Cycles by Trevor Hold: Pitt, Wilson-Johnson Dutton CDLX 7213 2008
No full textRecorded at Turner Sims Concert Hall, University of Southampton, 13-14 September & 20 December 2007The celebrated baritone David Wilson-Johnson makes his debut on Dutton Epoch, with soprano Amanda Pitt and pianist David Owen Norris in a heartfelt group of song- cycles by the Northamptonshire composer Trevor Hold. Following the success of Dutton Epoch’s recording of Hold’s song cycle The Unreturning Spring (CDLX 7196), the team present three of the composer’s engrossing song cycles: The Image Stays, River Songs and Voices from the Orchard. Norris and Wilson-Johnson, who have uniquely championed Trevor Hold’s music, include Voices from the Orchard, the composer’s tribute to his champions ‘the two Davids in memory of Henry Williamson’<br/
Anthropocene : a new geological epoch?
No full textThe Anthropocene is a new epoch proposed by Crutzen and Stoermer (2000), with a base at 1950 AD or 1800 AD. The present author doubts its value while studying Quaternary stratigraphic columns, as its base signal (Holocene/Anthropocene) might be unrecognizable in field sections. The usage of the Anthropocene epoch would probably be restricted to areas of massive direct negative human impact on Nature, predominantly in the Northern Hemisphere. In much less affected Southern Hemisphere deserts (Australia), mountain chains (the Andes), the near-pristine glaciated Antarctic continent and Subantarctic islands, separation of the Anthropocene time-unit (as a formal epoch) from the Holocene epoch would be artificial, even useless. On the other hand, the informal term might be useful for economic geographers, planners, sociologists, and Nature- protectionists
Montague Phillips Piano Concertos, and Victor Hely-Hutchinson, The Young Idea: Dutton CDLX 7206
No full textWorld premiere recordingsRecorded at The Colosseum, Town Hall, Watford, 14-15 January 2008The first two volumes of Montague Phillips’s tuneful orchestral music were warmly received when issued by Dutton Epoch. Now here is the third volume, presenting both Piano Concertos. In the 1960s the second of these was often heard on the BBC, but the first has not been heard for more than ninety years, the music found after a search of the family attic. Both are brilliantly played by pianist David Owen Norris, and will delight all those who have revelled in Dutton Epoch’s recordings of York Bowen’s piano concertos (available on CDLX 7169 & CDLX 7187). This is tuneful and enjoyable music, exquisitely scored and taking us back to the Edwardian world from which Montague Phillips - the pinnacle of light music composers - came. These are substantial concertos, and it is hard to explain why such charming music is not in the regular repertoire. To complete the disc, Victor Hely-Hutchinson’s short jazz concerto, The Young Idea, whirls us back to Billy Mayerl and the ballroom of the Savoy Hotel in the late 1920s.CDLX 7206<br/
Epoch alignment in stateful streams
No full textWhile the amount of data and variability in data produced by numerous systems in a modern company continues to increase, users desire real-time and consistent results from complex analyses across a large variety of event sources. In industry, stream processing systems are emerging to process events with low latency in a scalable and reliable fashion. As more and more stream processing jobs are processing mission critical events, older jobs are subject to maintenance and have to be upgraded or replaced. These upgrade operations include a snapshot-restore operation, where between the snapshot and restore a non-trivial state conversion has to be performed. Such an operation requires a lot of technical expertise and imposes significant down-time on the job itself and all jobs that depend on it. This thesis proposes a mechanism to align the progress of multiple independent jobs sharing common event sources. The mechanism is an extension of the checkpoint protocol proposed by Carbone et al. Not only does this mechanism simplify maintenance of streaming jobs by allowing hot-swap operations with exactly-once processing semantics, but it can also be used to provide consistency of queryable state. By implementing a proof of concept we show that this so called epoch alignment can be achieved with minimal additional costs over exactly-once processing semantics.CodefeedrComputer Scienc
Probing the relationship between electromagnetic ion cyclotron waves and plasmaspheric plumes near geosynchronous orbit
No full textPlasmaspheric plumes created during disturbed geomagnetic conditions have been suggested as a major cause of increased occurrences of electromagnetic ion cyclotron (EMIC) waves at these times. We have catalogued occurrences of strong Pc1 EMIC waves from 1996 through 2003 at three automated geophysical observatories operated by the British Antarctic Survey at auroral zone latitudes in Antarctica (L = 6.28, 7.68, and 8.07) and have compared them to the occurrence of plasmaspheric plumes in space, using simultaneous data from the Magnetospheric Plasma Analyzer on the Los Alamos National Laboratory 1990-095 spacecraft, in geosynchronous orbit at the same magnetic longitude. A superposed epoch analysis of these data was conducted for several categories of disturbed geomagnetic conditions, including magnetic storms, high-speed streams, and storm sudden commencements. We found only a weak correspondence between the occurrence of strong Pc1 waves observed on the ground and either plasmaspheric plumes or intervals of extended plasmasphere at geosynchronous orbit before, during, or after the onset of any of these categories. Strong Pc1 activity peaked near or slightly after local noon during all storm phases, consistent with equatorial observations by the Active Magnetospheric Particle Tracer Explorers/Charge Composition Explorer satellite at these L shells. The highest Pc1 occurrence probability was at or 1-2 days before storm onset and during the late recovery phase. Occurrence was lowest during the early recovery phase, consistent with the decrease in solar wind pressure often seen at this time. The peak at onset is consistent with earlier observations of waves in the outer magnetosphere stimulated by sudden impulses and magnetospheric compressions
VLASS Epoch 1 Catalogs
No full textPyBDSF and SExtractor detection catalogs for the VLA Sky Survey (VLASS)
Stroh, M. C., Terreran, G., Coppejans, D., Bright, J. and Margutti, R.
All authors currently at:
Center for Interdisciplinary Exploration and Research in Astrophysics (CIERA), 1800 Sherman Ave, 8th Floor, Evanston, IL 60201, USA
Department of Physics and Astronomy, Northwestern University, 2145 Sheridan Road, Evanston, IL 60208, USA
Corresponding author:
Stroh, M. C. - [email protected]
General notes about the files:
These files were created using the epochs 1.1 and 1.2 quicklook files for the VLA Sky Survey (VLASS, Lacy et al. 2020). Original files are saved in a csv format, and have been subsequently compressed. The columns from each file are defined from PyBDSF (Mohan & Rafferty 2015) or Source Extractor (SExtractor, Bertin & Arnouts 1996) output with the file name appended to each row. Files are ordered by VLASS file name, then by the detection ID defined by PyBDSF or SExtractor.
Included files:
1) vlass_epoch1_pybdsf_gaussian.csv.gz
Contains gaussian fits to detections in the VLASS epoch 1 Quick Look images using PyBDSF. These gaussians may be combined into sources in vlass_epoch1_pybdsf_source.csv.gz.
2) vlass_epoch1_pybdsf_source.csv.gz
Contains final source lists from PyBDSF from the VLASS epoch 1 Quick Look images after gaussians have been combined.
3) vlass_epoch1_sextractor.csv.gz
Contains detections from SExtractor in the VLASS epoch 1 Quick Look images.
Please refer to Stroh et al. (2021) for information on how PyBDSF and SExtractor were run to create these files.
For more information about specific columns, please refer to Mohan & Rafferty (2015) or Bertin & Arnouts (1996).
If using this catalog for publications, please cite Stroh et al. (2021)
Minimizing aborts in an epoch based transaction protocol for deterministic databases
No full textToday's need for highly available systems leads to data partitioning and replication across multiple nodes. Providing strong transactional consistency in a distributed database requires extensive communication. For this, algorithms such as two phase commit are used. These communication algorithms add extra network latency's. For application developers and database systems, this is the reason for lowering the isolation level of a database. Deterministic databases run transactions effectively without communication between replicas. Most deterministic databases need the read write sets of a transaction prior to execution to calculate a deterministic execution schedule. Aria does not need the read write sets a priory but uses an epoch based commit protocol. The commit protocol is an optimistic concurrency control algorithm that executes all transactions against a snapshot in the execution phase and determines which transactions can commit in the commit phase. For most workloads Aria outperforms state of the art deterministic databases. However, for high contention workloads Aria suffers performance because of high abort rates. To overcome this problem this thesis proposes two solutions: 1) Lowering the isolation level to snapshot isolation. 2) Reordering the input sequence of transactions on transaction degree. We have found that lowering the isolation level to snapshot isolation allows for 3\% less aborts per epoch and reduces latency from 210 ms to 170ms. Reordering the transaction sequence allows for 5 percent less aborts per epoch for snapshot isolation and serializable isolation level. Reordering transactions on degree for serializable isolation level reduces the average latency from 210 ms to 150 ms. Snapshot isolation reordering transactions on degree reduces the average latency from 170 ms to 120 ms.Computer Science | Software Technolog
A generic approach to parameterize the turbulent energy of single-epoch atmospheric delays from InSAR time-series
No full textThe observed phase in time series of interferometric synthetic aperture radar (InSAR) products is a superposition of various components. Differential topography, line-of-sight displacements, and differential atmospheric delays are the main contributions and need to be disentangled to derive accurate digital elevation model (DEM), deformation, or atmospherical products from InSAR. However, isolating the atmospheric component has been proven difficult as it is spatiotemporally highly dynamic and a superposition of two atmospheric states. Here, we propose an approach to parameterize the stochastic properties of the single-epoch atmospheric delay field as a way to define the atmospheric signal. We found that the atmospheric signal of a time series of interferograms can be characterized by structure functions, which can be used to isolate the single-epoch structure functions. Due to the scaling properties of the atmospheric signal, it is then possible to construct a parametric function per SAR acquisition, using two isotropic and three anisotropic parameters. In particular, the isotropic parameters for the short-distance variation and long-distance variation in atmospheric delay can be used to characterize the atmospheric signal. For a test set of 151 Sentinel-1 acquisitions, this results in an atmospheric energy range of about 10 for short-distance scales and about 50 for long-distance scales. Our parameterization demonstrates that we can describe the spatiotemporal variability of InSAR atmospheric delays, which provides a measure for atmospheric noise for individual epochs in deformation time series based on distance and azimuth.Geoscience and Remote SensingMathematical Geodesy and Positionin
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