MLPerf Inference Benchmark

Machine-learning (ML) hardware and software system demand is burgeoning. Driven by ML applications, the number of different ML inference systems has exploded. Over 100 organizations are building ML inference chips, and the systems that incorporate existing models span at least three orders of magnitude in power consumption and five orders of magnitude in performance; they range from embedded devices to data-center solutions. Fueling the hardware are a dozen or more software frameworks and libraries. The myriad combinations of ML hardware and ML software make assessing ML-system performance in an architecture-neutral, representative, and reproducible manner challenging. There is a clear need for industry-wide standard ML benchmarking and evaluation criteria. MLPerf Inference answers that call. In this paper, we present our benchmarking method for evaluating ML inference systems. Driven by more than 30 organizations as well as more than 200 ML engineers and practitioners, MLPerf prescribes a set of rules and best practices to ensure comparability across systems with wildly differing architectures. The first call for submissions garnered more than 600 reproducible inference-performance measurements from 14 organizations, representing over 30 systems that showcase a wide range of capabilities. The submissions attest to the benchmark's flexibility and adaptability.Comment: ISCA 202

Design and operation of the Chicago air shower array

The Chicago Air Shower Array (CASA) is a large‐area surface scintillator array designed to study PeV sources of cosmic rays. The complete detector will consist of 1089 detector stations, distributed on a square 15 m grid. We have operated an array of 49 stations for much of the 1989 calendar year, an array of 529 stations for much of 1990, and the balance of the 1089 stations will be operating in early 1991. This surface array, together with the University of Michigan underground muon detectors (MIA), and the University of Utah atmospheric Čerenkov telescopes and Fly’s Eye air fluorescence detector, constitute a uniquely powerful instrument, dubbed the Utah Michigan Chicago (UMC) experiment, for the study of PeV sources. We report here the performance and current status of these detectors.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87431/2/111_1.pd

Preliminary results from the Chicago air shower array and the Michigan muon array

The Chicago Air Shower Array (CASA) is a large area surface array designed to detect extensive air showers (EAS) produced by primaries with energy ∼100 TeV. It operates in coincidence with the underground Michigan Muon Array (MIA). Preliminary results are presented from a search for steady emission and daily emission from three astrophysical sources: Cygnus X‐3, Hercules X‐1, and the Crab nebula and pulsar. There is no evidence for a significant signal from any of these sources in the 1989 data.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87432/2/122_1.pd

CASA‐MIA: A ‘‘precision’’ EAS detector

The CASA‐MIA detector was constructed to search for sources of UHE neutral radiation. As such it has established limits well below those of previously reported observations and of most contemporaneous detectors. In addition to its primary mission, however, CASA‐MIA measures the lateral distribution of both electrons and muons in EAS throughout a range of energies and with a degree of sampling not previously available.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87669/2/207_1.pd

Search for Ultra High Energy (UHE) γ-ray counterparts of BATSE 3B catalog events

We search for a Ultra High Energy (E>1014 eV)(E>1014eV) counterpart source to cosmic γ-ray bursts detected with the BATSE detectors. Using the 3B catalog positions, we examine 115 candidate bursts with the CASA-MIA detector for UHE γ-ray emission at or near the time of the observed γ-ray burst. No statistically significant excess of γ-rays is found from any of the candidate event regions. Based upon these results, we calculate the flux limits for UHE emission from these candidate event regions. Typical 95% confidence level flux limits are about 6×10−12 γ  cm−2 sec−16×10−12γcm−2sec−1 at a γ-ray detection threshold of 160 TeV. © 1996 American Institute of Physics.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87368/2/598_1.pd

A search for diffuse gamma rays with energies above 1014 eV from molecular clouds in the galaxy

Diffuse gamma‐rays from molecular clouds are excellent tracers of cosmic rays in the galaxy over a wide range of energies. For example, diffuse emission detected by EGRET already places significant constraints on the spectrum and origin of galactic cosmic rays at GeV energies. Likewise, by measuring diffuse gamma rays with ground‐based air shower experiments, we can probe the galactic distribution of cosmic rays in the energy regime above 100 TeV.The Chicago Air Shower Array (CASA) which operates in coincidence with the Michigan muon array (MIA) is the world’s most sensitive experiment to gamma‐rays with energies ≳100 TeV, and is well‐suited for studies of diffuse sources based upon the muon content of air showers. We describe a search for diffuse gamma‐array emission from molecular cloud regions observed by CASA‐MIA. If we assume that the flux of cosmic rays is uniform in the galaxy, then we predict that diffuse emission will probably be detectable by CASA‐MIA within the lifetime of the experiment. Furthermore, if there are sources of cosmic rays in close proximity to certain molecular clouds, then the spectrum of gamma‐rays from these clouds will be stronger and harder. By searching for such enhancements in the diffuse emission, and by correlating the CASA‐MIA results with emission detected at lower energies by EGRET, we may identify or constrain the nature of cosmic rays sources in both energy regimes.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87646/2/499_1.pd

A search for astrophysical point sources of 100 TeV gamma rays by the UMC collaboration

The CASA‐MIA experiment is a very large extensive air shower detector with good angular resolution. This instrument has been used to search the entire visible sky for astrophysical point sources of 100 TeV gamma rays. Approximately 90% of the isotropic charged cosmic ray background is rejected by measuring the muon content of the showers. Stringent limits are placed on the possible flux of 100 TeV sources across a large part of the Northern sky.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/87711/2/1203_1.pd

Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

A measurement of the cosmic-ray spectrum for energies exceeding $4{\times}10^{18}$ eV is presented, which is based on the analysis of showers with zenith angles greater than $60^{\circ}$ detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above $5.3{\times}10^{18}$ eV, the "ankle", the flux can be described by a power law $E^{-\gamma}$ with index $\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)}$ followed by a smooth suppression region. For the energy ($E_\text{s}$) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find $E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19}$ eV.Comment: Replaced with published version. Added journal reference and DO

Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO