| 1. |
- Abelev, Betty, et al.
(author)
-
Long-range angular correlations on the near and away side in p-Pb collisions at root S-NN=5.02 TeV
- 2013
-
In: Physics Letters. Section B: Nuclear, Elementary Particle and High-Energy Physics. - : Elsevier BV. - 0370-2693. ; 719:1-3, s. 29-41
-
Journal article (peer-reviewed)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.
|
|
| 2. |
- Abelev, Betty, et al.
(author)
-
Measurement of prompt J/psi and beauty hadron production cross sections at mid-rapidity in pp collisions at root s=7 TeV
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :11
-
Journal article (peer-reviewed)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.
|
|
| 3. |
- Abelev, Betty, et al.
(author)
-
Underlying Event measurements in pp collisions at root s=0.9 and 7 TeV with the ALICE experiment at the LHC
- 2012
-
In: Journal of High Energy Physics. - 1029-8479. ; :7
-
Journal article (peer-reviewed)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%.
|
|
| 4. |
- Axelsson, Agnes, 1992-, et al.
(author)
-
Robots in autonomous buses: Who hosts when no human is there?
- 2024
-
In: HRI 2024 Companion - Companion of the 2024 ACM/IEEE International Conference on Human-Robot Interaction. - : Association for Computing Machinery (ACM). ; , s. 1278-1280
-
Conference paper (peer-reviewed)abstract
- In mid-2023, we performed an experiment in autonomous buses in Stockholm, Sweden, to evaluate the role that social robots might have in such settings, and their effects on passengers' feeling of safety and security, given the absence of human drivers or clerks. To address the situations that may occur in autonomous public transit (APT), we compared an embodied agent to a disembodied agent. In this video publication, we showcase some of the things that worked with the interactions we created, and some problematic issues that we had not anticipated.
|
|
| 5. |
|
|
| 6. |
- Bogdan, Cristian, et al.
(author)
-
Evaluation of robot body movements supporting communication : Towards HRI on the move
- 2011
-
In: New Frontiers in Human–Robot Interaction. - Philadelphia : John Benjamins Publishing Company. - 9789027204554 ; , s. 185-210
-
Book chapter (peer-reviewed)abstract
- In designing socially interactive robots we have focused on robot movement and its role in multi-modal human-robot communication. In this chapter we describe design and evaluation of robot body movements supporting communication, investigating the idea of using speed and orientation adjustments as design elements in human-robot interaction. The scenario studied includes a robotic shopping trolley that offers products via speech and GUI to the user while both are moving in a supermarket-like environment. Our results show that if the robot slows down while making such offers, users are more prone to react upon them and to take the product. However, even from our early pre-study with mock-up robots we observed that users tended not to mention the robot’s slow-down movements, even if these movements were shown several times to them during a video-based debriefing. This phenomenon, that users react implicitly on the robot’s movements without being consciously aware of them, was confirmed during an experimental study with a fully integrated robot prototype. We discuss our results by reflecting on human-robot interaction design methods, and we draw implications from the lessons learned in the study of the design of robot behaviours. In particular, we list a whole set of challenges for HRI when both the user and the robot are moving.
|
|
| 7. |
- Bogdan, Cristian, et al.
(author)
-
FingerPrint : supporting social awareness in a translucent sensor- mediated cue-based environment
- 2004
-
Conference paper (peer-reviewed)abstract
- We report on a pilot study that is part of an ongoing project which investigates social awareness support for project groups made of students who may choose to work at the university, at home or at part-time job offices. The study involved the design and early evaluation of a prototype which augments a cooperative application with various sensorial and computational cues about co-worker presence. The sensing devices were installed and annotated by the users themselves. Based on this experience and inspired by "technomethodology", we suggest implications for design of awareness support and context-enabled devices.
|
|
| 8. |
- Bogdan, Cristian, et al.
(author)
-
Generating an Abstract User Interface from a Discourse Model Inspired by Human Communication
- 2008
-
In: Proceedings of the 41st Annual Hawaii International Conference on System Sciences. ; , s. 36-46
-
Conference paper (peer-reviewed)abstract
- Inspired by Human Communication Cristian Bogdan, Jürgen Falb, Hermann Kaindl, Sevan Kavaldjian, Roman Popp, Helmut Horacek, Edin Arnautovic and Alexander Szep Vienna University of Technology, Institute of Computer Technology A 1040 Vienna, Austria {bogdan, falb, kaindl, kavaldjian, popp, horacek, arnautovic, szep}@ict.tuwien.ac.at Abstract Programming user interfaces is hard, error-prone and expensive, but recent advances allow generating them from interaction design models. We present an approach for modeling interaction design that is inspired by human com- munication. Our interaction design models are discourse models, more precisely models of dialogues. They are based on theories of human communication and should, therefore, be more understandable to humans than programs imple- menting user interfaces. The main ingredients of our mod- els are communicative acts (Speech Act Theory), which are connected as adjacency pairs (Conversation Analysis) and via RST relations (Rhetorical Structure Theory). While RST provides useful means for modeling discourse in the sense of monologue, a dialogue results from connecting monologues via adjacency pairs. This paper presents a new metamodel that integrates these approaches. Based on it, we show how abstract user interfaces can be generated from such dis- course models. In a nutshell, we generate finite-state ma- chinery and employ rules devised by us to map parts of a discourse model to abstract widgets.
|
|
| 9. |
- Bogdan, Cristian, 1971-
(author)
-
IT Design for Amateur Communities
- 2003
-
Doctoral thesis (other academic/artistic)abstract
- The concept of community is receiving increasing attentionacross organizations and throughout the entire society.Voluntary association, creation of value, and solidarity incommunity contexts get more and more appreciated and nurturedwithin companies and other organizations. At the same time,lack of community is raised lately by Western sociologists as amajor source of alarm while the large participationpossibilities provided by the Internet are seen as a hope forremedy.This thesis aims to contribute in the area of technologydesign for communities by seeking to gain understanding ofvoluntary community work and to design artefacts in support forsuch work. Community work is studied through anethnographically-inspired approach for empirical observation ofcommunity activity and the artefacts that support it. Fieldstudy of‘voluntary working order’was conducted inseveral voluntary communities: amateur radio and three studentorganisations. In studying such working order, one mustrenounce a set of assumptions that are commonly made aboutwork, starting with the very idea of remuneration as a basicmotivation. Instead, challenge as a major motivation isproposed for work in voluntary communities. To draw inspirationfor future design, an examination is made of the way thismotivation is reflected in the features of technology createdby the communities for their own use, in the working contextsof the field settings.Lessons learned about amateur work are then used and refinedwhile reflecting on amateur-work-oriented design of ITartefacts conducted within a student organisation, with aparticular interest in self-sustainability of participatorydesign practices in such settings. Practices of participatorydesign are re-considered in the context of voluntary work, theabsence of the employer-employee conflict, the challenges andlearning trajectories of the members. As development is done bymembers of the student community, design interventions forself-sustainability of amateur software development aredescribed and reflected upon. A generic approach is proposedfor action aimed at self-sustainability in amateur settings.The socio-technical features that resemble across thecommunities studied and practices experienced are then groupedunder the generic name of the perspective developed in thisthesis:“Amateur Community”. The perspective isproposed as a point of departure for further study and designintervention in similar communities. Comparisons are madebetween Amateur Community and other approaches such asCommunity of Practice.Keywords:amateur, volunteer, community, work, amateurwork, participatory design, software development, challenge,contingency, pioneering, public, personal development,learning, hands-on learning, selfsustainability
|
|
| 10. |
- Bogdan, Cristian
(author)
-
Longstanding success without awareness support : lessons from a collaborative programming tool
- 2008
-
In: Proceedings of COOP 2008, Institut d'Etudes Politiques, Aix-en-Provence.
-
Conference paper (peer-reviewed)abstract
- The paper is a reflective account of a successful five-year experience with a Web-based collaborative programming environment for nomadic student programmers. While after implementing the basic functionality there were good opportunities for collecting and providing awareness information within the tool, resources did not permit that. Still, the users appreciated the tool and inferred the needed awareness information or provided for it using other channels like instant messaging. This experience suggests that well-designed basic articulation is much more important than awareness for the success of collaborative tools.
|
|
