Bits missing: finding exotic pulsars using bfloat16 on NVIDIA GPUs

The Fourier domain acceleration search (FDAS) is an effective technique for detecting faint binary pulsars in large radio astronomy data sets. This paper quantifies the sensitivity impact of reducing numerical precision in the graphics processing unit (GPU)-accelerated FDAS pipeline of the AstroAccelerate (AA) software package. The prior implementation used IEEE-754 single-precision in the entire binary pulsar detection pipeline, spending a large fraction of the runtime computing GPU-accelerated fast Fourier transforms. AA has been modified to use bfloat16 (and IEEE-754 double-precision to provide a “gold standard” comparison) within the Fourier domain convolution section of the FDAS routine. Approximately 20,000 synthetic pulsar filterbank files representing binary pulsars were generated using SIGPROC with a range of physical parameters. They have been processed using bfloat16, single-precision, and double-precision convolutions. All bfloat16 peaks are within 3% of the predicted signal-to-noise ratio of their corresponding single-precision peaks. Of 14,971 “bright” single-precision fundamental peaks above a power of 44.982 (our experimentally measured highest noise value), 14,602 (97.53%) have a peak in the same acceleration and frequency bin in the bfloat16 output plane, while in the remaining 369 the nearest peak is located in the adjacent acceleration bin. There is no bin drift measured between the single- and double-precision results. The bfloat16 version of FDAS achieves a speedup of approximately 1.6× compared to single-precision. A comparison between AA and the PRESTO software package is presented using observations collected with the GMRT of PSR J1544+4937, a 2.16 ms black widow pulsar in a 2.8 hr compact orbit

A Practical Guide to the New European Bauhaus Self-assessment Method and Tool

This handbook provides a complete guide to the New European Bauhaus (NEB) self-assessment method, designed to promote the three NEB dimensions, namely sustainability, beauty, and inclusiveness, in the built environment of Europe and beyond. The handbook comes together with an online tool allowing to evaluate the performance of projects and support their improvement. The online tool is seen as the basis to establish a dialogue between all involved stakeholders, and the grounds for defining minimum performance levels within the NEB framework. Advanced targets and indices are proposed to help professionals assess all aspects of the three NEB dimensions in buildings and living spaces, promote sustainable economic and financial activities, overcome local constraints, and improve the quality of life of the European citizens, indoors and outdoors, through a built environment designed to be affordable, aesthetically appealing, healthy, comfortable, and accessible for everyone, also addressing safety, functionality under hazards, adaptation to new functions. Acknowledging the complexity of a comprehensive evaluation, and understanding the variability of metrics associated with the three NEB dimensions across different project types, scales, and geographical regions, the self-assessment method is structured hierarchically to provide feedback with three interconnected assessment levels: indicator, key performance indicator, and dimension. Specifically, the method defines three spatial scales, i.e. building, neighbourhood, and urban, and delineates two project types, i.e. newbuild and renovation. Supporting the self-assessment process, the online tool aims to facilitate the user and simplify the evaluation process while upholding the method integrity and effectiveness. This handbook offers a thorough guidance on the New European Bauhaus self-assessment method and its underlying principles. It covers assessment targets, indicators, key performance indicators, evaluation methods, and measurement units. Additionally, the handbook includes illustrative examples, empowering the interested users with the knowledge necessary to perform the evaluation effectively. The handbook primarily targets professionals engaged in both the delivery phase (design, construction, and commissioning) and the operational phase (operations and maintenance). Project managers, architects, engineers, and consultants are anticipated to play an active role in gathering and generating the information needed for the self-assessment. However, various stakeholders throughout the entire building lifecycle and supply chains are also expected to participate, benefit from, and be influenced by the assessment, including product manufacturers, main and specialist contractors, policymakers, building users and the local community members directly impacted by the project outcomes. The method is not intended to foster competition or reward high-scoring projects; rather, its purpose is to drive continuous improvement in the built environment quality and align projects with the NEB objectives. Whereas users are expected to aim at the highest performance in the self-assessment, the decision of focusing more on some performance indicators rather than others is finally left each user. To emphasise the significance of a balanced performance across all three dimensions of projects, the possibility of obtaining a global performance combining the three NEB dimension scores was intentionally excluded

HARMONI at ELT: project status and instrument overview

International audienceHARMONI is the first light visible and near-IR integral field spectrograph for the ELT. It covers a large spectral range from 450 nm to 2450 nm with resolving powers from 3500 to 18000 and spatial sampling from 60 mas to 4 mas. It can operate in two Adaptive Optics modes - SCAO (including a High Contrast capability) and LTAO - or with NOAO. The project is preparing for Final Design Reviews. HARMONI is a work-horse instrument that provides efficient, spatially resolved spectroscopy of extended objects or crowded fields of view. The gigantic leap in sensitivity and spatial resolution that HARMONI at the ELT will enable promises to transform the landscape in observational astrophysics in the coming decade. The project has undergone some key changes to the leadership and management structure over the last two years. We present the salient elements of the project restructuring, and modifications to the technical specifications. The instrument design is very mature in the lead up to the final design review. In this paper, we provide an overview of the instrument's capabilities, details of recent technical changes during the red flag period, and an update of sensitivities

Pulsar acceleration searches on the GPU for the Square Kilometre Array

Pulsar acceleration searches are methods for recovering signals from radio telescopes, that may otherwise be lost due to the effect of orbital acceleration in binary systems. The vast amount of data that will be produced by next generation instruments such as the Square Kilometre Array (SKA) necessitates real-time acceleration searches, which in turn requires the use of HPC platforms. We present our implementation of the Fourier Domain Acceleration Search (FDAS) algorithm on Graphics Processor Units (GPUs) in the context of the SKA, as part of the Astro-Accelerate real-time data processing library, currently under development at the Oxford e-Research Centre (OeRC), University of Oxford

Searching for pulsars in extreme orbits — GPU acceleration of the Fourier domain 'jerk' search

Binary pulsars are an important target for radio surveys because they present a natural laboratory for a wide range of astrophysics for example testing general relativity, including detection of gravitational waves. The orbital motion of a pulsar which is locked in a binary system causes a frequency shift (a Doppler shift) in their normally very periodic pulse emissions. These shifts cause a reduction in the sensitivity of traditional periodicity searches. To correct this smearing Ransom [2001], Ransom et al. [2002] developed the Fourier domain acceleration search (FDAS) which uses a matched filtering technique. This method is however limited to a constant pulsar acceleration. Therefore, Andersen and Ransom [2018] broadened the Fourier domain acceleration search to account also for a linear change in the acceleration by implementing the Fourier domain "jerk" search into the PRESTO software package. This extension increases the number of matched filters used significantly. We have implemented the Fourier domain "jerk" search (JERK) on GPUs using CUDA. We have achieved 90x performance increase when compared to the parallel implementation of JERK in PRESTO. This work is part of the AstroAccelerate project Armour et al. [2019], a many-core accelerated time-domain signal processing library for radio astronomy

Multi-year application of the three-dimensional numerical generation of response factors (NGRF) method in the prediction of conductive temperatures in soil and passive cooling earth-contact components

A recently developed method named the three-dimensional numerical generation of response factors NGRF (Zoras and Kosmopoulos, 2009) was claimed to be fast, accurate and flexible as a result of incorporating elements of the response factor method into a finite volume technique based numerical model. The presented paper reports on the application of the NGRF method for the numerical prediction of temperatures within and around structural passive cooling components over multi-year temperature profiles. Once the numerical temperature response factors time series of an earth-contact component's grid node had been generated then its future thermal performance due to any surrounding temperature variation can be predicted fast and accurately. The NGRF method was, successfully, applied through an intermodel testing procedure to simulate soil and structural earth-contact passive cooling component temperatures for multiple years. © 2011 Elsevier Ltd