1,133 research outputs found
ALICE Data Challenges
When fully operational, the ALICE experiment will take data at a rate of 1.5 GB/s. This rate is more than an order of magnitude higher than that of the other LHC experiments. To be ready for this very high rate and to understand early on what the possible problems might be, we have decided to start the ALICEData Challenges (ADC). The idea is that the ADCs will be repeated once or twice a year until the LHC goes online. The unique aspect of the ADCs is that it involves the complete ALICE data taking chain: form DAQ, via event builder, via filter, to object database to mass storage system. Progressively, with each ADC we shall try to achieve higher data rates, more realistic event filters and raw data models
The ALICE Off-Line Strategy: A Successful Migration to OO
The ALICE Experiment has chosen to start developing its software directly in OO, using the services of the ROOT system, which is ALICE's official candidate for the common LHC framework. This had lead to the definition of a complete environment (AliRoot) where the software developed by the different experimental groups is being integrated. Different test-benches for I/O and Simulation have been set up based on real production code. This allows early assessment of technology, both software and hardware in a realistic production environment. Different codes, such as GEANT3, GEANT4 and FLUKA, or the reconstruction algorithms by the physicists developing the detectors, have been easily integrated in the framework, that has shown to be both evolutive and modular.The ALICE Collaboration has adopted this setup and we are now successfully migrating the users into it. This talk describes the AliRoot environment and its future evolution
ROOT, an object oriented data analysis framework
ROOT is an object-oriented framework aimed at solving the data analysis challenges of high-energy physics. Here we discuss the main components of the framework. We begin with an overview describing the framework's organization, the interpreter CINT, its automatic interface to the compiler and linker ACLiC, and an example of a first interactive session. The subsequent sections cover histogramming and fitting. Then, ROOT's solution to storing and retrieving HEP data, building and managing of ROOT files, and designing ROOT trees. Followed by a description of the collection classes, the GUI classes, how to add your own classes to ROOT, and PROOF, ROOT's parallel processing facility
Into the Crucible. Methodological approaches to reconstructing crucible metallurgy, from New Kingdom Egypt to Late Roman Thrace
The subject of this PhD thesis is the study of ancient metallurgical crucible assemblages, with a particular focus on the methodological framework for such studies. This is approached through three case studies from the eastern Mediterranean: Qantir – Pi-Ramesse (Ramesside Egypt, 13th century BC), Gordion (Late Phrygian/Achaemenid Anatolia, 6th-4th century BC) and Nicopolis/Philippopolis/Serdica/Stara Zagora (Roman Thrace, 2nd-5th century AD). For each of these three case studies, the metallurgical activities are reconstructed and contextualised. This involves determining the technical processes, material use and organisation of metal production both on the site and regional scale. No relation exists between these sites and each case study stands on its own: results from the technological reconstruction are interpreted within their particular archaeological and regional/historical context, to which they offer novel contributions. The main research material consists of crucible remains, and to a lesser extent metal remains, which are investigated using optical microscopy and SEM(-EDS) to establish the technological processes and material use. The applicability of handheld XRF for such reconstructions is evaluated as well. Finally, lead isotope analysis (using MC-ICP-MS) of metal remains (scrap, spills, ingots, objects and prills extracted from crucible slag) and crucible ceramic and slag is performed. The overarching goal of this research is to evaluate methodological approaches to the study of crucibles and crucible assemblages by comparing the results for these three examples, not in terms of technology, but by evaluating the influence of varying crucible typology, preservation, abundance, contextual information, and sample availability, as well as the use of various analytical techniques. These considerations are then combined to formulate more general recommendations for the sampling, examination and interpretation of ancient crucible assemblages
Developments in ROOT I/O and trees
For the last several months the main focus of development in the ROOT I/O
package has been code consolidation and performance improvements. Access to
remote files is affected both by bandwidth and latency. We introduced a
pre-fetch mechanism to minimize the number of transactions between client and
server and hence reducing the effect of latency. We will review the
implementation and how well it works in different conditions (gain of an order
of magnitude for remote file access). We will also review new utilities,
including a faster implementation of TTree cloning (gain of an order of
magnitude), a generic mechanism for object references, and a new entry list
mechanism tuned both for small and large number of selections. In addition to
reducing the coupling with the core module and becoming its owns library
(libRIO) (as part of the general restructuration of the ROOT libraries), the
I/O package has been enhanced in the area of XML and SQL support, thread
safety, schema evolution, TTreeFormula, and many other areas. We will also
discuss various ways, ROOT will be able to benefit from multi-core architecture
to improve I/O performances
Проблемы формирования государственной экологической политики в условиях ограниченности ресурсов
Проблема ограниченности ресурсов является основой развития экономики. Однако также ограниченность оказывает влияние и на экологическую политику в стране. В статье рассмотрены ключевые механизмы формирования государственной экологической политики, экологического менеджмента; предложены пути повышения эффективности экологической политики.The problem of limited resources is the basis for economic development. However, the limited nature also influences the environmental policy in the country. The article considers the key mechanisms for the formation of state environmental policy, environmental management; ways to improve the effectiveness of environmental policy
The Usage of ROOT for Online Monitoring in the ALICE DATE System
Presentation for CHEP2000Data Acquisition systems for HEP applications need constant monitoring (online and offline) of their data streams to accomplish several tasks: quality checking, tuning, statistics, pre-analysis. Monitoring tasks can and should use the same tools as data analysis products (conventions, libraries, environments) to reduce training, installation, development and support efforts and -at the same time - to strengthen the liaison between the online and the offline worlds. The ALICE DATE Data Acquisition system available today for R&D and for test beams is fully integrated with the ROOT environment. A simple DAQ-oriented approach and a more complex OO-based model have been developed to allow a variety of programming paradigms and to validate the complete life cycle of monitoring tools, both for online and offline environments
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Brain MR Spectroscopy Changes Precede Frontotemporal Lobar Degeneration Phenoconversion in Mapt Mutation Carriers.
Background and purposeThe objective of this study was to longitudinally investigate the trajectory of change in 1 H MRS measurements in asymptomatic MAPT mutation carriers who became symptomatic during follow-up, and to determine the time at which the neurochemical alterations accelerated during disease progression.MethodsWe identified eight MAPT mutations carriers who transitioned from asymptomatic to symptomatic disease during follow-up. All participants were longitudinally followed with an average of 7.75 years (range 4-11 years) and underwent two or more single voxel 1 H MRS examinations from the posterior cingulate voxel, with a total of 60 examinations. The rate of longitudinal change for each metabolite was estimated using linear mixed models. A flex point model was used to estimate the flex time point of the change in slope.ResultsThe decrease in the NAA/mI ratio accelerated 2.09 years prior to symptom onset, and continued to decline. A similar trajectory was observed in the presumed glial marker mI/Cr ratio accelerating 1.86 years prior to symptom onset.ConclusionsOur findings support the potential use of longitudinal 1 H MRS for monitoring the neurodegenerative progression in MAPT mutation carriers starting from the asymptomatic stage
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