| 1. |
- Abelev, Betty, et al.
(författare)
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Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
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Ingår i: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
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Tidskriftsartikel (refereegranskat)abstract
- Angular correlations between charged trigger and associated particles are measured by the ALICE detector in p-Pb collisions at a nucleon-nucleon centre-of-mass energy of 5.02 TeV for transverse momentum ranges within 0.5 < P-T,P-assoc < P-T,P-trig < 4 GeV/c. The correlations are measured over two units of pseudorapidity and full azimuthal angle in different intervals of event multiplicity, and expressed as associated yield per trigger particle. Two long-range ridge-like structures, one on the near side and one on the away side, are observed when the per-trigger yield obtained in low-multiplicity events is subtracted from the one in high-multiplicity events. The excess on the near-side is qualitatively similar to that recently reported by the CMS Collaboration, while the excess on the away-side is reported for the first time. The two-ridge structure projected onto azimuthal angle is quantified with the second and third Fourier coefficients as well as by near-side and away-side yields and widths. The yields on the near side and on the away side are equal within the uncertainties for all studied event multiplicity and p(T) bins, and the widths show no significant evolution with event multiplicity or p(T). These findings suggest that the near-side ridge is accompanied by an essentially identical away-side ridge. (c) 2013 CERN. Published by Elsevier B.V. All rights reserved.
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| 2. |
- Abelev, Betty, et al.
(författare)
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Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :11
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Tidskriftsartikel (refereegranskat)abstract
- The ALICE experiment at the LHC has studied J/psi production at mid-rapidity in pp collisions at root s = 7 TeV through its electron pair decay on a data sample corresponding to an integrated luminosity L-int = 5.6 nb(-1). The fraction of J/psi from the decay of long-lived beauty hadrons was determined for J/psi candidates with transverse momentum p(t) > 1,3 GeV/c and rapidity vertical bar y vertical bar < 0.9. The cross section for prompt J/psi mesons, i.e. directly produced J/psi and prompt decays of heavier charmonium states such as the psi(2S) and chi(c) resonances, is sigma(prompt J/psi) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 8.3 +/- 0.8(stat.) +/- 1.1 (syst.)(-1.4)(+1.5) (syst. pol.) mu b. The cross section for the production of b-hadrons decaying to J/psi with p(t) > 1.3 GeV/c and vertical bar y vertical bar < 0.9 is a sigma(J/psi <- hB) (p(t) > 1.3 GeV/c, vertical bar y vertical bar < 0.9) = 1.46 +/- 0.38 (stat.)(-0.32)(+0.26) (syst.) mu b. The results are compared to QCD model predictions. The shape of the p(t) and y distributions of b-quarks predicted by perturbative QCD model calculations are used to extrapolate the measured cross section to derive the b (b) over bar pair total cross section and d sigma/dy at mid-rapidity.
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| 3. |
- Abelev, Betty, et al.
(författare)
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Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
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Ingår i: Journal of High Energy Physics. - 1029-8479. ; :7
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Tidskriftsartikel (refereegranskat)abstract
- We present measurements of Underlying Event observables in pp collisions at root s = 0 : 9 and 7 TeV. The analysis is performed as a function of the highest charged-particle transverse momentum p(T),L-T in the event. Different regions are defined with respect to the azimuthal direction of the leading (highest transverse momentum) track: Toward, Transverse and Away. The Toward and Away regions collect the fragmentation products of the hardest partonic interaction. The Transverse region is expected to be most sensitive to the Underlying Event activity. The study is performed with charged particles above three different p(T) thresholds: 0.15, 0.5 and 1.0 GeV/c. In the Transverse region we observe an increase in the multiplicity of a factor 2-3 between the lower and higher collision energies, depending on the track p(T) threshold considered. Data are compared to PYTHIA 6.4, PYTHIA 8.1 and PHOJET. On average, all models considered underestimate the multiplicity and summed p(T) in the Transverse region by about 10-30%.
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| 4. |
- Boix, E. G., et al.
(författare)
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Workshop preview of the 2015 workshop on programming based on actors, agents, and decentralized control (AGERE! 2015)
- 2015
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Ingår i: SPLASH Companion 2015 - Companion Proceedings of the 2015 ACM SIGPLAN International Conference on Systems, Programming, Languages and Applications. - New York, NY, USA : ACM. - 9781450337229 ; , s. 99-100
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Konferensbidrag (refereegranskat)abstract
- The AGERE! workshop focuses on programming systems, languages and applications based on actors, active/concurrent objects, agents and - more generally - high-level programming paradigms promoting a mindset of decentralized control in solving problems and developing software. The workshop is designed to cover both the theory and the practice of design and programming, bringing together researchers working on models, languages and technologies, and practitioners developing real-world systems and applications.
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| 5. |
- Boutet, S., et al.
(författare)
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High-Resolution Protein Structure Determination by Serial Femtosecond Crystallography
- 2012
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Ingår i: Science. - : American Association for the Advancement of Science (AAAS). - 0036-8075 .- 1095-9203. ; 337:6092, s. 362-364
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Tidskriftsartikel (refereegranskat)abstract
- Structure determination of proteins and other macromolecules has historically required the growth of high-quality crystals sufficiently large to diffract x-rays efficiently while withstanding radiation damage. We applied serial femtosecond crystallography (SFX) using an x-ray free-electron laser (XFEL) to obtain high-resolution structural information from microcrystals (less than 1 micrometer by 1 micrometer by 3 micrometers) of the well-characterized model protein lysozyme. The agreement with synchrotron data demonstrates the immediate relevance of SFX for analyzing the structure of the large group of difficult-to-crystallize molecules.
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| 6. |
- Donaldson, Alastair F., et al.
(författare)
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Software verification using k-induction
- 2011
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Ingår i: Static Analysis. - Berlin, Heidelberg : Springer Berlin/Heidelberg. - 9783642237010 ; , s. 351-368
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Konferensbidrag (refereegranskat)
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| 7. |
- Glassey, Richard, et al.
(författare)
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Addressing the double challenge of learning and teaching enterprise technologies through peer teaching
- 2020
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Ingår i: Proceedings - International Conference on Software Engineering. - New York, NY, USA : IEEE Computer Society. ; , s. 130-138
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Konferensbidrag (refereegranskat)abstract
- Students face difficulties when transitioning from introductory programming to using more complex enterprise technologies, such as libraries, software frameworks and development kits. Whilst much literature has been devoted to how to teach introductory programming effectively, less attention is devoted towards managing the transition towards more complex technologies. This work presents the design, experience and evaluation of a module that engages students with a range of enterprise technologies. The module uses peer teaching to transfer the responsibility to students for teaching each other about the technologies. As such, this reduces the need for the teacher to invest time in preparing materials, and it is feasible to cover more technologies depending upon the number of teaching teams. The evaluation, conducted on a cohort of 34 students studying six enterprise technologies over the course of one week, revealed overwhelmingly positive experiences with this approach. For the teacher, effort for preparation and delivery was minimal, and the feedback on the module was highly positive.
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| 8. |
- Glassey, Richard, et al.
(författare)
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Agile and adaptive learning via the ECK-model in the software development academy
- 2018
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Ingår i: CEUR Workshop Proceedings. - : CEUR-WS.
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Konferensbidrag (refereegranskat)abstract
- This paper reports the learning management experiences within an intensive three-month education that helps newly arrived in Sweden find work as IT professionals. The creation of the Software Development Academy was motivated by the migration crisis and the wider need to help integrate newcomers into the social and professional landscape. Despite having relevant skills and training, many have had their studies and careers disrupted either by conflict, or simply by lacking the profile and networks needed to restart their careers in a new country. With limited resources and time, combined with the intensive pace and diverse student backgrounds, the program faces many challenges that threaten its success. To mitigate these challenges, an agile and adaptive approach was adopted that employs TEL techniques and pedagogical concepts to ensure the program is continuously improving via short iterations and tight feedback loops. The program has just finished its third offering and has continuously improved through weekly collection of knowledge, confidence, and experience data that guide interventions and reactions as they are needed. The experience, process, and model presented here may inspire and benefit other courses with similar profiles and challenges.
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| 9. |
- Haller, Philipp, et al.
(författare)
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A programming model and foundation for lineage-based distributed computation
- 2018
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Ingår i: Journal of functional programming (Print). - : Cambridge University Press. - 0956-7968 .- 1469-7653. ; 28
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Tidskriftsartikel (refereegranskat)abstract
- The most successful systems for "big data" processing have all adopted functional APIs. We present a new programming model, we call function passing, designed to provide a more principled substrate, or middleware, upon which to build data-centric distributed systems like Spark. A key idea is to build up a persistent functional data structure representing transformations on distributed immutable data by passing well-typed serializable functions over the wire and applying them to this distributed data. Thus, the function passing model can be thought of as a persistent functional data structure that is distributed, where transformations performed on distributed data are stored in its nodes rather than the distributed data itself. One advantage of this model is that failure recovery is simplified by design - data can be recovered by replaying function applications atop immutable data loaded from stable storage. Deferred evaluation is also central to our model; by incorporating deferred evaluation into our design only at the point of initiating network communication, the function passing model remains easy to reason about while remaining efficient in time and memory. Moreover, we provide a complete formalization of the programming model in order to study the foundations of lineage-based distributed computation. In particular, we develop a theory of safe, mobile lineages based on a subject reduction theorem for a typed core language. Furthermore, we formalize a progress theorem that guarantees the finite materialization of remote, lineage-based data. Thus, the formal model may serve as a basis for further developments of the theory of data-centric distributed programming, including aspects such as fault tolerance. We provide an open-source implementation of our model in and for the Scala programming language, along with a case study of several example frameworks and end-user programs written atop this model.
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| 10. |
- Haller, Philipp, et al.
(författare)
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A reduction semantics for direct-style asynchronous observables
- 2019
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Ingår i: The Journal of logical and algebraic methods in programming. - : ELSEVIER SCIENCE INC. - 2352-2208 .- 2352-2216. ; 105, s. 75-111
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Tidskriftsartikel (refereegranskat)abstract
- Asynchronous programming has gained in importance, not only due to hardware developments like multi-core processors, but also due to pervasive asynchronicity in client-side Web programming and large-scale Web applications. However, asynchronous programming is challenging. For example, control-flow management and error handling are much more complex in an asynchronous than a synchronous context. Programming with asynchronous event streams is especially difficult: expressing asynchronous stream producers and consumers requires explicit state machines in continuation-passing style when using widely-used languages like Java. In order to address this challenge, recent language designs like Google's Dart introduce asynchronous generators which allow expressing complex asynchronous programs in a familiar blocking style while using efficient non-blocking concurrency control under the hood. However, several issues remain unresolved, including the integration of analogous constructs into statically-typed languages, and the formalization and proof of important correctness properties. This paper presents a design for asynchronous stream generators for Scala, thereby extending previous facilities for asynchronous programming in Scala from tasks/futures to asynchronous streams. We present a complete formalization of the programming model based on a reduction semantics and a static type system. Building on the formal model, we contribute a complete type soundness proof, as well as the proof of a subject reduction theorem which establishes that the programming model enforces an important state transition protocol for asynchronous streams. (C) 2019 Elsevier Inc. All rights reserved.
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