bluuebunny/crossref_metadata_2025 huggingface dataset:
Combining autoclave and LCWM reactor studies to shed light on the kinetics of glucose oxidation catalyzed by doped molybdenum-based heteropoly acids
Authors: Voß Dorothea , Ponce Sebastian , Wesinger Stefanie , Etzold Bastian J. M. , Albert Jakob
Published: September 2019

In this work we combined kinetic studies for aqueous-phase glucose oxidation in a high-pressure autoclave setup with catalyst reoxidation studies in a liquid-core waveguide membrane reactor.
Rotary manifold for automating a paper-basedSalmonellaimmunoassay
Authors: Carrell Cody S. , Wydallis Rachel M. , Bontha Mridula , Boehle Katherine E. , Beveridge J. Ross , Geiss Brian J. , Henry Charles S.
Published: September 2019

Easy-to-use rotary manifold enables an immunomagnetic separation sandwich immunoassay for foodborne pathogen detection at the point-of-need.
Impact of dihydrogen bonding on lattice energies and sublimation enthalpies of crystalline [H2GaNH2]3, [H2BNH2]3 and [H2GeCH2]3
Authors: Gladfelter Wayne L. , Cramer Christopher J.
Published: September 2019

Calculated lattice energies and sublimation enthalpies provide quantitative measures of the importance of intermolecular dihydrogen bonds.
Slide electrification: charging of surfaces by moving water drops
Authors: Stetten Amy Z. , Golovko Dmytro S. , Weber Stefan A. L. , Butt Hans-Jürgen
Published: September 2019

We investigate the charge separation caused by the motion of a water drop across a hydrophobic, insulating solid surface.
Nano-Cu-embedded carbon for dendrite-free lithium metal anodes
Authors: Wang Zhuo , Yu Zhuo , Wang Bingliang , Guo Zhaowei , Wang Nan , Wang Yonggang , Xia Yongyao
Published: September 2019

Copper–organic framework-derived material is applied as a host for Li plating/stripping. The resulting anode exhibits dendrite-free Li deposition and high efficiency. The corresponding capacitor and battery display good electrochemical performance.
Control of aggregation and dissolution of small molecule hole transport layers via a doping strategy for highly efficient perovskite solar cells
Authors: Ali Jazib , Song Jingnan , Li Yu , Qian Kun , Zhang Quanzeng , Zhou Guanqing , Zhang Ming , Zhu Lei , Qiu Chaoqun , Xu Jinqiu , Wang Jing , Haider Rizwan , Feng Wei , Hu Hailin , Zhu Haiming , Zhang Yongming , Liu Feng
Published: September 2019

Polymeric dopant strategy distinctly suppressed the molecular aggregations and surface dewetting of the NPB small molecule hole transport layer in perovskite photovoltaics.
Effect of conjugation length on the properties of fused perylene diimides with variable isoindigos
Authors: Yu Yaping , Xue Ning , Xiao Chengyi , Ravva Mahesh Kumar , Guo Yanjun , Wu Liyun , Zhang Lei , Li Zhengke , Yue Wan , Wang Zhaohui
Published: September 2019

We have synthesized a series of fused hybrid perylene diimides and isoindigos, and investigated their structure–property relationships.
Broadband spectral analysis of MXB 1659−298 in its soft and hard state
Authors: Iaria R. , Mazzola S. M. , Bassi T. , Gambino A. F. , Marino A. , Di Salvo T. , Sanna A. , Riggio A. , Burderi L. , D’Amico N.
Published: September 2019

Context. The X-ray transient eclipsing source MXB 1659−298 went into outburst in 1999 and 2015. During these two outbursts the source was observed by XMM-Newton, NuSTAR, and Swift/XRT.

Aims. Using these observations, we studied the broadband spectrum of the source to constrain the continuum components and to verify whether it had a reflection component, as is observed in other X-ray eclipsing transient sources.

Methods. We combined the available spectra to study the soft and hard state of the source in the 0.45–55 keV energy range.

Results. We report a reflection component in the soft and hard state. The direct emission in the soft state can be modeled with a thermal component originating from the inner accretion disk plus a Comptonized component associated with an optically thick corona surrounding the neutron star. On the other hand, the direct emission in the hard state is described only by a Comptonized component with a temperature higher than 130 keV; this component is associated with an optically thin corona. We observed narrow absorption lines from highly ionized ions of oxygen, neon, and iron in the soft spectral state. We investigated where the narrow absorption lines form in the ionized absorber. The equivalent hydrogen column density associated with the absorber is close to 6 × 1023 cm−2 and 1.3 × 1023 cm−2 in the soft and hard state, respectively.
The most massive, passive, and oldest galaxies at 0.5 < z < 2.1: Downsizing signature from galaxies selected from MgUV index
Authors: Thomas R. , Le Fèvre O. , Zamorani G. , Lemaux B. C. , Hibon P. , Koekemoer A. , Hathi N. , Maccagni D. , Cassata P. , Cassarà L. P. , Bardelli S. , Talia M. , Zucca E.
Published: September 2019

Aims. We seek is to identify old and massive galaxies at 0.5 < z < 2.1 on the basis of the magnesium index MgUV and then study their physical properties.

Methods. We computed the MgUV index based on the best spectral fitting template of ∼3700 galaxies using data from the VLT VIMOS Deep Survey (VVDS) and VIMOS Ultra Deep Survey (VUDS) galaxy redshift surveys. Based on galaxies with the largest signal to noise and the best fit spectra we selected 103 objects with the highest spectral MgUV signature. We performed an independent fit of the photometric data of these galaxies and computed their stellar masses, star formation rates, extinction by dust and age, and we related these quantities to the MgUV index.

Results. We find that the MgUV index is a suitable tracer of early-type galaxies at an advanced stage of evolution. Selecting galaxies with the highest MgUV index allows us to choose the most massive, passive, and oldest galaxies at any epoch. The formation epoch tf computed from the fitted age as a function of the total mass in stars supports the downsizing formation paradigm in which galaxies with the highest mass formed most of their stars at an earlier epoch.
A stellar census in globular clusters with MUSE: multiple populations chemistry in NGC 2808
Authors: Latour M. , Husser T.-O. , Giesers B. , Kamann S. , Göttgens F. , Dreizler S. , Brinchmann J. , Bastian N. , Wendt M. , Weilbacher P. M. , Molinski N. S.
Published: September 2019

Context. Galactic globular clusters (GCs) are now known to host multiple populations displaying particular abundance variations. The different populations within a GC can be well distinguished following their position in the pseudo two-colors diagrams, also referred to as “chromosome maps”. These maps are constructed using optical and near-UV photometry available from the Hubble Space Telescope (HST) UV survey of GCs. However, the chemical tagging of the various populations in the chromosome maps is hampered by the fact that HST photometry and elemental abundances are both only available for a limited number of stars.

Aims. The spectra collected as part of the MUSE survey of globular clusters provide a spectroscopic counterpart to the HST photometric catalogs covering the central regions of GCs. In this paper, we use the MUSE spectra of 1115 red giant branch (RGB) stars in NGC 2808 to characterize the abundance variations seen in the multiple populations of this cluster.

Methods. We used the chromosome map of NGC 2808 to divide the RGB stars into their respective populations. We then combined the spectra of all stars belonging to a given population, resulting in one high signal-to-noise ratio spectrum representative of each population.

Results. Variations in the spectral lines of O, Na, Mg, and Al are clearly detected among four of the populations. In order to quantify these variations, we measured equivalent width differences and created synthetic populations spectra that were used to determine abundance variations with respect to the primordial population of the cluster. Our results are in good agreement with the values expected from previous studies based on high-resolution spectroscopy. We do not see any significant variations in the spectral lines of Ca, K, and Ba. We also do not detect abundance variations among the stars belonging to the primordial population of NGC 2808.

Conclusions. We demonstrate that in spite of their low resolution, the MUSE spectra can be used to investigate abundance variations in the context of multiple populations.
Data Acquisition and Software for the ATLAS Tile Calorimeter Phase-II Upgrade Demonstrator
Authors: Yue Xiaoguang
Published: September 2019

After a series of upgrades, the High Luminosity LHC (HL-LHC) will have an instantaneous luminosity of 5-7 times larger than the LHC design value. The readout electronics of the ATLAS Tile Calorimeter (TileCal) will undergo a substantial upgrade during the Phase-II upgrade to accommodate the HL-LHC requirements. After the Phase-II upgrade, the TileCal detector signals will be digitized by on-detector electronics and transferred to the the TileCal PreProcessors (TilePPr), which is a part of the off-detector electronics. In the TilePPr, the digitized data will be stored in pipeline buffers and be packed and readout to the Front-End Link eXchange (FELIX) system upon receiving a trigger decision. At the same time, the energy information will be reconstructed from the detector data and transferred to the Level-1 Calorimeter Trigger (L1Calo) system in different granularity for every bunch crossing. The TileCal Demonstrator is designed to evaluate the performance of the TileCal with new readout electronics without compromising the present data taking. This contribution describes in detail the data processing and the hardware, firmware, software components of the TileCal Demonstrator system, together with the results of beam tests performed at CERN.
DDS: The Dynamic Deployment System
Authors: Lebedev Andrey , Manafov Anar
Published: September 2019

The Dynamic Deployment System (DDS) [1, 2] is a tool-set that automates and significantly simplifies the deployment of user-defined processes and their dependencies on any resource management system (RMS) using a given topology. DDS is a part of the ALFA framework [3].

DDS implements a single responsibility principle command line tool-set and API. The system treats users’ taskas a black box – it can be an executable or a script. It also provides a watchdogging and a rule-based execution of tasks. DDS implements a plug-in system to abstract the execution of the topology from RMS. Additionally it ships an SSH and a localhost plug-ins which can be used when no RMS is available. DDS doesn’t require pre-installation and pre-configuration on the worker nodes. It deploys private facilities on demand with isolated sandboxes.The system provides a key-value property propagation engine. That engine can be used to configure tasks at runtime. DDS also provides a lightweight API for tasks to exchange messages, so-called, custom commands.

In this report a detailed description, current status and future development plans of the DDS will be highlighted.
Felix Based Readout of The Single-Phase Protodune Detector
Authors: Borga Andrea , Church Eric , Filthaut Frank , Gamberini Enrico , Paul de Jong , Habraken René , Lehmann Miotto Giovanna , Miedema Thijs , Schreuder Frans , Schumacher Jörn , Sipos Roland , Vermeulen Milo , Wood Lynn
Published: September 2019

The liquid argon Time Projection Chamber technique has matured and is now in use by several short-baseline neutrino experiments. This technology will be used in the long-baseline DUNE experiment; however, this experiment represents a large increase in scale, for which the technology needs to be validated explicitly. To this end, both the single-phase and dual-phase implementations of the technology are being tested at CERN in two full-scale (10 × 10 × 10 m3) ProtoDUNE setups. Besides the detector technology, these setups also allow for extensive tests of readout strategies.

The Front-End LInk eXchange (FELIX) system was initially developed within the ATLAS collaboration and is based on custom FPGA-based PCIe I/O cards in combination with commodity servers. FELIX will be used in the single-phase ProtoDUNE setup to read the data coming from 2560 anode wires organized in a single Anode Plane Assembly structure. With a sampling rate of 2 MHz, the system must buffer and process an input rate of 74 Gb/s. Event building requests will arrive at a target rate of 25 Hz, and loss-less compression must reduce the data within the requested time windows before it is sent to the experiment’s event building farm.

This paper discusses the design of the system as well as first operational experiences.
The Online Monitoring API for the DIALOG Library of the COMPASS Experiment
Authors: Šubrt Ondřej , Bodlák Martin , Frolov Vladimir , Huber Stefan , Jandek Matouš , Jarý Vladimίr , Květoň Antonίn , Levit Dmytro , Nový Josef , Steffen Dominik , Tomsa Jan , Virius Miroslav
Published: September 2019

Modern experiments demand a powerful and efficient Data Acquisition System (DAQ). The intelligent, FPGA-based Data Acquisition System (iFDAQ) of the COMPASS experiment at CERN is composed of many processes communicating between each other. The DIALOG library covers a communication mechanism between processes and establishes a communication layer to each of them. It has been introduced to the iFDAQ in the Run 2016 and improved significantly the stability of the system. The paper presents the online monitoring API for the DIALOG library. Communication between processes is challenging from a synchronization, reliability and robustness point of view. Online monitoring tools of the communication between processes are capable to reveal communication problems to be fixed in future. The debugging purpose has been crucial during introduction period to the iFDAQ. On the other hand, based on the measurement of communication between processes, the proper load balancing of processes among machines can improve the stability of the system. The online monitoring API offers a general approach for the implementation of many monitoring tools with different purposes. In the paper, it is discussed its fundamental concept, integration to a new monitoring tool and a few examples of monitoring tools are given.
Run Control Software For The Upgrade Of The Atlas Muon To Central Trigger Processor Interface (MUCTPI)
Authors: Spiwoks Ralf , Armbruster Aaron , Carrillo-Montoya German , Chelstowska Magda , Czodrowski Patrick , Deviveiros Pier-Olivier , Eifert Till , Ellis Nick , Farthouat Philippe , Galster Gorm , Haas Stefan , Helary Louis , Kuzmanovic Predrag , Lagkas Nikolos Orestis , Marzin Antoine , Pauly Thilo , Ryjov Vladimir , Schmieden Kristof , Silva Oliveira Marcos , Stelzer Joerg , Vichoudis Paschalis , Wengler Thorsten
Published: September 2019

The Muon to Central Trigger Processor Interface (MUCTPI) of the ATLAS experiment at the Large Hadron Collider(LHC) at CERN is being upgraded for the next run of the LHC in order to use optical inputs and to provide full-precision information for muon candidates to the topological trigger processor (L1TOPO) of the Level-1 trigger system. The new MUCTPI is implemented as a single ATCA blade with high-end processing FPGAs which eliminate doublecounting of muon candidates in overlapping regions, send muon candidates to L1TOPO, and muon multiplicities tothe Central Trigger Processor (CTP), as well as readout data to the data acquisition system of the experiment. A Xilinx Zynq System-on-Chip (SoC) with a programmable logic part and a processor part is used for the communication to the processing FPGAs and the run control system. The processor part, based on ARM processor cores, is running embedded Linux prepared using the framework of the Linux Foundation's Yocto project. The ATLAS run control software was ported to the processor part and a run control application was developed which receives, at configuration, all data necessary for the overlap handling and candidate counting of the processing FPGAs. During running, the application provides ample monitoring of the physics data and of the operation of the hardware. *
The Data Acquisition System of the Na62 Experiment at Cern
Authors: Boretto Marco
Published: September 2019

The aim of the NA62 experiment is to study the extreme rare kaon decay K+ ? π+vv and to measure its branching ratio with a 10% accuracy. In order to do so, a very high intensity beam from the CERN SPS is used to produce charged kaons whose decay products are detected by many detectors installed along a 60 m decay region. The NA62 Data Acquisition system (DAQ) exploits a multi-level trigger system; following a Level0 (L0) trigger decision, 1 MHz data rate from about 60 sources is read by a PC-farm, the partial event is built and then passed through a series of Level1 (L1) algorithms to further reduce the trigger rate. Events passing this level are completed with the missing, larger, data sources (~400 sources) at the rate of 100 KHz. The DAQ is built around a high performance ethernet network interconnecting the detectors to a farm of 30 servers. After an overall description of the system design and the main implementation choices that allowed to reach the required performance and functionality, this paper describes the overall behaviour of the DAQ in the 2017 data taking period. It then concludes with an outlook of possible improvements and upgrades that may be applied to the system in the future.
The Impact of Applying Wildcards to Disabled Modules for Ftk Pattern Banks on Efficiency and Data Flow
Authors: Bouaouda Khalil , Schmitt Stefan , Benchekroun Driss
Published: September 2019

Online selection is an essential step to collect the most relevant collisions from the very large number of collisions inside the ATLAS detector at the Large Hadron Collider (LHC). The Fast TracKer (FTK) is a hardware based track finder, built to greatly improve the ATLAS trigger system capabilities for identifying interesting physics processes through track-based signatures. The FTK is reconstructing after each Level-1 trigger all tracks with pT > 1 GeV, such that the high-level trigger system gains access to track information at an early stage. FTK track reconstruction starts with a pattern recognition step. Patterns are found with hits in seven out of eight possible detector layers.

Disabled detector modules, as often encountered during LHC operation, lead to efficiency losses. To recover efficiency, WildCards (WC) algorithms are implemented in the FTK system. The WC algorithm recovers inefficiency but also causes high combinatorial background and thus increased data volumes in the FTK system, possibly exceeding hardware limitations. To overcome this, a refined algorithm to select patterns is developed and investigated in this article.
Multi-turn track fitting for the COMET experiment
Authors: Zhang Yao , Nakatsugawa Yohei , Li Haibo , Yuan Ye , Xing Tianyu
Published: September 2019

The reconstruction of multi-turn curling tracks is a big challenge for the drift chamber of the COMET [1] experiment. A method of deterministic annealing filter that implements a global competition between hits from different turns is introduced. This method assigns the detector measurements to the candidate track based on the weighted mean of fitting quality on different turns. We present here the study of multi-turn track fitting based on the simulated tracks. We found that the algorithm can successfully distinguish the hits from different turns.
Impact of detector simulation in particle physics collider experiments - highlights
Authors: Elvira V. Daniel
Published: September 2019

Detector simulation has become fundamental to the success of modern high-energy physics (HEP) experiments. For example, the Geant4-based simulation applications developed by the ATLAS and CMS experiments played a major role for them to produce physics measurements of unprecedented quality and precision with faster turnaround, from data taking to journal submission, than any previous hadron collider experiment. The material presented here contains highlights of a recent review on the impact of detector simulation in particle physics collider experiments published in Ref. [1]. It includes examples of applications to detector design and optimization, software development and testing of computing infrastructure, and modeling of physics objects and their kinematics. The cost and economic impact of simulation in the CMS experiment is also presented. A discussion on future detector simulation needs, challenges and potential solutions to address them is included at the end.
Going standalone and platform-independent, an example from recent work on the ATLAS Detector Description and interactive data visualization
Authors: Merkt Sebastian Andreas , Bianchi Riccardo Maria , Boudreau Joseph , Gessinger-Befurt Paul , Moyse Edward , Salzburger Andreas , Tsulaia Vakhtang
Published: September 2019

Until recently, the direct visualization of the complete ATLAS experiment geometry and physics objects was confined within the software framework of the experiment. To provide a detailed interactive data visualization capability to users, as well as easy access to geometry data, and to ensure platform independence and portability, great effort has been recently put into the modernization of both the core kernel of the detector description and the visualization tools. In this proceedings we will present the new tools, as well as the lessons learned while modernizing the experiment’s code for an efficient use of the detector description and for user-friendly data visualization.
The INFN scientific computing infrastructure: present status and future evolution
Authors: Boccali T. , Carlino G. , dell’Agnello L.
Published: September 2019

The INFN scientific computing infrastructure is composed of more than 30 sites, ranging from CNAF (Tier-1 for LHC and main data center for nearly 30 other experiments) and nine LHC Tier-2s, to ∼ 20 smaller sites, including LHC Tier-3s and not-LHC experiment farms. A comprehensive review of the installed resources, together with plans for the near future, has been collected during the second half of 2017, and provides a general view of the infrastructure, its costs and its potential for expansions; it also shows the general trends in software and hardware solutions utilized in a complex reality as INFN. As of the end of 2017, the total installed CPU power exceeded 800 kHS06 (∼ 80,000 cores) while the total storage net capacity was over 57 PB on disk and 97 PB on tape: the vast majority of resources (95% of cores and 95% of storage) are concentrated in the 16 largest centers. Future evolutions are explored and are towards the consolidation into big centers; this has required a rethinking of the access policies and protocols in order to enable diverse scientific communities, beyond LHC, to fruitfully exploit the INFN resources. On top of that, such an infrastructure will be used beyond INFN experiments, and will be part of the Italian infrastructure, comprising other research institutes, universities and HPC centers.
The XENON1T Data Distribution and Processing Scheme
Authors: Ahlin Daniel , Bauermeister Boris , Conrad Jan , Gardner Robert , Grandi Luca , Riedel Benedikt , Shockley Evan , Stephen Judith , Sundblad Ragnar , Thapa Suchandra , Tunnell Christopher
Published: September 2019

The XENON experiment is looking for non-baryonic particle dark matter in the universe. The setup is a dual phase time projection chamber (TPC) filled with 3200 kg of ultra-pure liquid xenon. The setup is operated at the Laboratori Nazionali del Gran Sasso (LNGS) in Italy. We present a full overview of the computing scheme for data distribution and job management in XENON1T. The software package Rucio, which is developed by the ATLAS collaboration, facilitates data handling on Open Science Grid (OSG) and European Grid Infrastructure (EGI) storage systems. A tape copy at the Centre for High Performance Computing (PDC) is managed by the Tivoli Storage Manager (TSM). Data reduction and Monte Carlo production are handled by CI Connect which is integrated into the OSG network. The job submission system connects resources at the EGI, OSG, SDSC’s Comet, and the campus HPC resources for distributed computing.

The previous success in the XENON1T computing scheme is also the starting point for its successor experiment XENONnT, which starts to take data in autumn 2019.
Performance of the AMS Offline Software at National Energy Research Scientific Computing Centre and Argonne Leadership Computing Facility
Authors: Choutko Vitali , Egorov Alexander , Eline Alexandre , Shan Baosong
Published: September 2019

The Alpha Magnetic Spectrometer [1] (AMS) is a high energy physics experiment installed and operating on board of the International Space Station (ISS) from May 2011 and expected to last through year 2024 and beyond. More than 50 million of CPU hours has been delivered for AMS Monte Carlo simulations using NERSC and ALCF facilities in 2017. The details of porting of the AMS software to the 2nd Generation Intel Xeon Phi Knights Landing architecture are discussed, including the MPI emulation module to allow the AMS offline software to be run as multiple-node batch jobs. The performance of the AMS simulation software at NERSC Cori (KNL 7250), ALCF Theta (KNL 7230), and Mira (IBM BG/Q) farms is also discussed.
Running IceCube GPU simulations on Titan
Authors: Brik Vladimir , Schultz David , Merino Gonzalo
Published: September 2019

Here we report IceCube’s first experiences of running GPU simulations on the Titan supercomputer. This undertaking was non-trivial because Titan is designed for High Performance Computing (HPC) workloads, whereas IceCube’s workloads fall under the High Throughput Computing (HTC) category. In particular: (i) Titan’s design, policies, and tools are geared heavily toward large MPI applications, while IceCube’s workloads consist of large numbers of relatively small independent jobs, (ii) Titan compute nodes run Cray Linux, which is not directly compatible with IceCube software, and (iii) Titan compute nodes cannot access outside networks, making it impossible to access IceCube’s CVMFS repositories and workload management systems. This report examines our experience of packaging our application in Singularity containers and using HTCondor as the second-level scheduler on the Titan supercomputer.
EGI Dataset Accounting and the WLCG
Authors: Coveney Adrian , Corbett Greg
Published: September 2019

This paper reviews the prototype dataset accounting developed during the EGI-Engage project and how it could be used to complement the view that the WLCG has of its datasets. This is a new feature of the EGI resource accounting system that will enable storing information on dataset usage such as who has accessed a dataset and how often. The new REST interface used for retrieving usage metrics from the EGI DataHub is described as well as further work that is required.
EventDB: an event-based indexer and caching system for BESIII experiment
Authors: Cheng Yaodong , Li Haibo , Xu Qi , Cheng Zhenjing , Huang Qiulan
Published: September 2019

Beijing Spectrometer (BESIII) experiment has produced hundreds of billions of events. The traditional event-wise accessing of BESIII Offline Software System is not effective for the selective accessing with low rate during a physics analysis. In this paper, an event-based data management system (EventDB) is introduced, which can effectively alleviate the problems of low efficiency of data processing and low utilization of resources. Firstly, an indexing system based on NoSQL database is designed. By extracting specified attributes of events, the events interested to the physicists are selected and stored into the database, whilst the real data of event is still stored in ROOT files. For those hot events, the real event data can also be cached into EventDB to improve the access performance. The data analysis workflow of HEP experiments is needed to change if the EventDB system is applied. The analysis program queries the corresponding event index from database, then get event data from database if the event is cached, or get data from ROOT files if it is not cached. Finally, the test on more than one hundred billion physics events shows the query speed was greatly improved over traditional file-based data management systems.
Dynamic and on demand data streams
Authors: Duranti Matteo , Formato Valerio , Vagelli Valerio
Published: September 2019

Replicability and efficiency of data processing on the same data samples are a major challenge for the analysis of data produced by HEP experiments. High level data analyzed by end-users are typically produced as a subset of the whole experiment data sample to study interesting selection of data (streams). For standard applications, streams may be eventually copied from servers and analyzed on local computing centers or user machine clients. The creation of streams as copy of a subset of the original data results in redundant information stored in filesystems and may be not efficient: if the definition of streams changes, it may force a reprocessing of the low-level files with consequent impact on the data analysis efficiency. We propose an approach based on a database of lookup tables intended for dynamic and on-demand definition of data streams. This enables the end-users, as the data analysis strategy evolves, to explore different definitions of streams with minimal cost in computing resources. We also present a prototype demonstration application of this database for the analysis of the AMS-02 experiment data.
Providing large-scale disk storage at CERN
Authors: Rousseau Hervé , Chan Kwok Cheong Belinda , Contescu Cristian , Espinal Curull Xavier , Iven Jan , Gonzalez Labrador Hugo , Lamanna Massimo , Lo Presti Giuseppe , Mascetti Luca , Moscicki Jakub , van der Ster Dan
Published: September 2019

The CERN IT Storage group operates multiple distributed storage systems and is responsible for the support of the infrastructure to accommodate all CERN storage requirements, from the physics data generated by LHC and non-LHC experiments to the personnel users' files.

EOS is now the key component of the CERN Storage strategy. It allows to operate at high incoming throughput for experiment data-taking while running concurrent complex production work-loads. This high-performance distributed storage provides now more than 250PB of raw disks and it is the key component behind the success of CERNBox, the CERN cloud synchronisation service which allows syncing and sharing files on all major mobile and desktop platforms to provide offline availability to any data stored in the EOS infrastructure. CERNBox recorded an exponential growth in the last couple of year in terms of files and data stored thanks to its increasing popularity inside CERN users community and thanks to its integration with a multitude of other CERN services (Batch, SWAN, Microsoft Office).

In parallel CASTOR is being simplified and transitioning from an HSM into an archival system, focusing mainly in the long-term data recording of the primary data from the detectors, preparing the road to the next-generation tape archival system, CTA.

The storage services at CERN cover as well the needs of the rest of our community: Ceph as data back-end for the CERN OpenStack infrastructure, NFS services and S3 functionality; AFS for legacy home directory filesystem services and its ongoing phase-out and CVMFS for software distribution. In this paper we will summarise our experience in supporting all our distributed storage system and the ongoing work in evolving our infrastructure, testing very-dense storage building block (nodes with more than 1PB of raw space) for the challenges waiting ahead.
A Git-based Conditions Database backend for LHCb
Authors: Clemencic Marco
Published: September 2019

LHCb has been using the CERN/IT developed Conditions Database library COOL for several years, during LHC Run 1 and Run 2. With the opportunity window of the second long shutdown of LHC, in preparation for Run 3 and the upgraded LHCb detector, we decided to investigate alternatives to COOL as Conditions Database backend. In particular, given our conditions and detector description data model, we investigated the possibility of reusing the internal Git repository database as a conditions storage, and we adopted it since 2017 data taking. The adoption of Git gave us improved performance, smaller storage size and simplified maintenance and deployment.

In this paper we describe the implementation of our Git Conditions Database and the way it simplified our detector description and conditions development workflow.
Final Analysis Sample Metadata
Authors: Meade Patrick
Published: September 2019

IceCube is a cubic kilometer neutrino detector located at the
South Pole. Data are processed and filtered in a data center at the site. After
transfer to a data warehouse in the northern hemisphere, data are further
refined through multiple levels of selection and reconstruction to generate
analysis samples. So far, the production and curation of these analysis
samples has been handled in an ad-hoc way in IceCube. New tools have
been developed to capture and validate the metadata associated to these
data samples in consistent and machine readable specifications.
Development was driven by analysis use-cases and pursuing
reproducibility of scientific results..
IceCube File Catalog
Authors: Brik Vladimir , Meade Patrick , Merino Gonzalo , Oertlin Jan , Schultz David , Skarlupka Heath
Published: September 2019

IceCube is a cubic kilometer neutrino detector located at the
south pole. Metadata for files in IceCube have traditionally been handled
on an application by application basis, with no user-facing access. There
has been no unified view of data files, and users often query the filesystem
to locate files. Recently effort has been put into creating a unified view in a
central metadata catalog. Going for a simple solution, we created a userfacing
REST API backed by a NoSQL database. All major data producers
add their metadata to this central catalog. Schema generation is identified
as an important aspect of multi-application metadata services.
Extending ROOT through Modules
Authors: Shadura Oksana , Bockelman Brian Paul , Vassilev Vassil
Published: September 2019

The ROOT software framework is foundational for the HEP ecosystem, providing multiple capabilities such as I/O, a C++ interpreter, GUI, and math libraries. It uses object-oriented concepts and build-time components to layer between them. We believe that a new layering formalism will benefit the ROOT user community.

We present the modularization strategy for ROOT which aims to build upon the existing source components, making available the dependencies and other metadata outside of the build system, and allow post-install additions on top of existing installation as well as in the ROOT runtime environment. Components can be grouped into packages and made available from repositories in order to provide a post-install step of missing packages. This feature implements a mechanism for the more comprehensive software ecosystem and makes it available even from a minimal ROOT installation. As part of this work, we have reduced inter-component dependencies in order to improve maintainability. The modularization effort draws inspiration from similar efforts in the Java, Python, and Swift ecosystems. Keeping aligned with modern C++, this strategy relies on forthcoming features such as C++ modules. We hope formalizing the component layer provides simpler ROOT installs, improves extensibility, and decreases the complexity of embedding ROOT in other ecosystems.
Floating-point profiling of ACTS using Verrou
Authors: Grasland Hadrien , Févotte François , Lathuilière Bruno , Chamont David
Published: September 2019

Floating-point computations play a central role in scientific computing. Achieving high numerical stability in these computations affects not just correctness, but also computing efficiency, by accelerating the convergence of iterative methods and expanding the available choices of precision. The ACTS project aims at establishing an experiment-agnostic track reconstruction toolkit. It originates from the ATLAS Run2 tracking software and has already received strong adoption by FCC-hh. It is also being evaluated for possible use by the CLICdp and Belle 2 experiments.

In this study, Verrou, a Valgrind-based tool for dynamic instrumentation of floating-point computations, was applied to the ACTS codebase for the dual purpose of evaluating its numerical stability and investigating possible avenues for use of reduced-precision arithmetic.
Exploring polyglot software frameworks in ALICE FairMQ and fer
Authors: Binet Sébastien
Published: September 2019

In order to meet the challenges of the Run 3 data rates and volumes, the ALICE collaboration is merging the online and offline infrastructures into a common framework: ALICE-O2. O2 is based on FairRoot and FairMQ, a message-based, multi-threaded and multi-process control frame-work. In FairMQ, processes (possibly on different machines) exchange data via message queues either through 0MQ or nanomsg. In turn, this enables developers to write their reconstruction or analysis process in whatever language they choose or deem appropriate for the task at hand, as long as that programming language can send and receive data through these message queues. This paper introduces fer, a Go-based toolkit that interoperates with the C++ toolkit FairMQ, to explore the realm of polyglot distributed frameworks.
gopaw, a refactoring of CERN-PAW by using the softinex tools
Authors: Barrand Guy
Published: September 2019

gopaw is for the "Good Old PAW". We present the motivations to do such a program along with the technical choices to do it.
Application of a Convolutional Neural Network for image classification for the analysis of collisions in High Energy Physics
Authors: Madrazo Celia Fernández , Heredia Ignacio , Lloret Lara , Marco de Lucas Jesús
Published: September 2019

The application of deep learning techniques using convolutional neural networks for the classification of particle collisions in High Energy Physics is explored. An intuitive approach to transform physical variables, like momenta of particles and jets, into a single image that captures the relevant information, is proposed. The idea is tested using a well-known deep learning framework on a simulation dataset, including leptonic ttbar events and the corresponding background at 7 TeV from the CMS experiment at LHC, available as Open Data. This initial test shows competitive results when compared to more classical approaches, like those using feedforward neural networks.
A further reduction in CMS event data for analysis: the NANOAOD format
Authors: Rizzi Andrea , Petrucciani Giovanni , Peruzzi Marco
Published: September 2019

A new event data format has been designed and prototyped by the CMS collaboration to satisfy the needs of a large fraction of physics analyses (at least 50%) with a per event size of order 1 kB. This new format is more than a factor of 20 smaller than the MINIAOD format and contains only top level information typically used in the last steps of the analysis. The talk will review the current analysis strategy from the point of view of event format in CMS (both skims and formats such as RECO, AOD, MINIAOD, NANOAOD) and will describe the design guidelines for the new NANOAOD format.
Columnar data processing for HEP analysis
Authors: Pivarsk Jim , Nandi Jaydeep , Lange David , Elmer Peter
Published: September 2019

In the last stages of data analysis, physicists are often forced to choose between simplicity and execution speed. In High Energy Physics (HEP), high-level languages like Python are known for ease of use but also very slow execution. However, Python is used in speed-critical data analysis in other fields of science and industry. In those fields, most operations are performed on Numpy arrays in an array programming style; this style can be adopted for HEP by introducing variable-sized, nested data structures. We describe how array programming may be extended for HEP use-cases and an implementation known as awkward-array. We also present integration with ROOT, Apache Arrow, and Parquet, as well as preliminary performance results.
Deep Learning Approach to Track Reconstruction in the upgraded VELO
Authors: Rinnert Kurt , Cristoforetti Marco
Published: September 2019

The LHCb experiment will undergo a major upgrade for LHC Run III, scheduled to start taking data in 2021. In order to exploit the full physics potential of the upgraded detector, LHCb will employ a high level event filter entirely implemented in software. The event filter has to operate in real time at the 40 MHz LHC bunch crossing rate. The LHCb collaboration is currently exploring a variety of new new computing paradigms in order to cope with the challenges posed by the high data taking rates.

One contribution to this effort is the application of Machine Learning (ML) techniques to particle track reconstruction.

We explore an ML approach to the track reconstruction in the upgraded LHCb Vertex Locator (VELO). The reconstruction algorithm is evaluated with fully simulated Minimum-Bias data that reflects the input to the real time event filter. We have achieved a reasonable track reconstruction efficiency and low ghost rate with our first approach and are currently exploring several methods to further quality of the track reconstruction.
Developing a Declarative Analysis Language: LINQToROOT
Authors: Watts Gordon
Published: September 2019

The HEP community is preparing for the LHC’s Run 3 and 4. One of the big challenges for physics analysis will be developing tools to efficiently express an analysis and able to efficiently process the x10 more data expected. Recently, interest has focused on declarative analysis languages: a way of specifying a physicists’ intent and leaving everything else to the underlying system. The underlying system takes care of finding the data - powering the event processing loop – and even exactly how to most efficiently apply a desired jet selection. If this works, this would allow an analyser to test their algorithm on a small amount of data on their GPU-less laptop and then run it on a large amount of data on a server with multiple large GPU’s without having to alter their code. The LINQToROOT project, started almost seven years ago, fits this model. It has been used and tested in three ATLAS published analyses. LINQToROOT is based on the Language Integrated Query system built into the cross-platform C# language. It enables writing strongly-typed queries on a ROOT’s TTree’s data and transcribes the data to a C++ algorithm that can run in ROOT. Recent work on this system has had two goals: improving analysis efficiency and better understanding the requirements of a declarative analysis language. For example, a good analysis language should be able to abstract away the backend – recent work has increased the possible back ends from formerly the single Windows ROOT backend to one that runs on Linux, the Windows Linux-subsystem, and an experimental one that allows for PROOF like parallel processing – all done with almost no change to the analysis code itself. Any analysis language must also be rich enough to support an experiment’s data model. To test this, some experiments with the full ATLAS xAOD data model have been performed. All of this has been done while attempting to keep the project close to its original goals: quick turnaround for real ATLAS physics analysis. This work will be discussed in some detail along with thoughts and lessons that have helped shape our thinking about an Analysis Language and perhaps our approach to future physics analysis employing declarative analysis.
CAOS: a tool for OpenStack accounting management
Authors: Andreetto Paolo , Chiarello Fabrizio , Traldi Sergio
Published: September 2019

The analysis and understanding of resources utilization in shared infrastructures, such as cloud environments, is crucial in order to provide better performance, administration and capacity planning.

The management of resource usage of the OpenStack-based cloud infrastructures hosted at INFN-Padova, the Cloud Area Padovana and the INFN-PADOVA-STACK instance of the EGI Federated cloud, started with the deployment of Ceilometer, the OpenStack component responsible for collecting and managing accounting information. However, by using Ceilometer alone we found some limiting problems related to the way it handles information: among others, the imbalance between storage and data retention requirements, and the complexity in computing custom metrics.

In this contribution we present a tool, called CAOS, which we have been implementing to overcome the aforementioned issues. CAOS collects, manages and presents the data concerning resource usage of our OpenStack-based cloud infrastructures. By gathering data from both the Ceilometer service and Open-Stack API, CAOS enables us to track resource usage at different levels (e.g. per project), in such a way that both current and past consumption ofresources can be easily determined, stored and presented.
The cloud of geographically distributed data centers
Authors: Fedchenkov Petr , Shevel Andrey , Khoruzhnikov Sergey , Sadov Oleg , Lazo Oleg , Samokhin Nikitta
Published: September 2019

ITMO University (ifmo.ru) is developing the cloud of geographically distributed data centres. The geographically distributed means data centres (DC) located in different places far from each other by hundreds or thousands of kilometres. Usage of the geographically distributed data centres promises a number of advantages for end users such as opportunity to add additional DC and service availability through redundancy and geographical distribution. Services like data transfer, computing, and data storage are provided to users in the form of virtual objects including virtual machines, virtual storage, virtual data transfer link.
Using the Autopilot pattern to deploy container resources at a WLCG Tier-2
Authors: Roy Gareth , Simili Emanuele , Skipsey Samuel Cadellin , Stewart Gordon , Britton David
Published: September 2019

Containers are becoming ubiquitous within the WLCG, with CMS announcing a requirement for its sites to provide Singularity during 2018. The ubiquity of containers means it is now possible to reify the combination of an
application and its configuration into a single easy-to-deploy unit, avoiding the need to make use of a myriad of configuration management tools such as Puppet, Ansible or Salt. This allows use to be made of industry-standard devops techniques within the operations domain, such as Continuous Integration (CI) and Continuous Deployment (CD), which can lead to faster upgrades and greater system security. One interesting technique is the Autopilot pattern, which provides mechanisms for application life-cycle management which are accessible from within the container itself. Using modern service discovery techniques, each container manages its own configuration, monitors its own health, and adapts to changing requirements through the use of event triggers. In this paper, we expand on previous work to create and deploy resources to a WLCG Tier-2 via containers, and investigate the viability of using the Autopilot pattern at a WLCG site to deploy and manage computational resources.