366,012 research outputs found
Coordination, Division of Labor, and Open Content Communities: Template Messages in Wiki-Based Collections
In this paper we investigate how in commons based peer production a large community of contributors coordinates its efforts towards the production of high quality open content. We carry out our empirical analysis at the level of articles and focus on the dynamics surrounding their production. That is, we focus on the continuous process of revision and update due to the spontaneous and largely uncoordinated sequence of contributions by a multiplicity of individuals. We argue that this loosely regulated process, according to which any user can make changes to any entry, while allowing highly creative contributions, has to come into terms with potential issues with respect to the quality and consistency of the output. In this respect, we focus on emergent, bottom up organizational practice arising within the Wikipedia community, namely the use of template messages, which seems to act as an effective and parsimonious coordination device in emphasizing quality concerns (in terms of accuracy, consistency, completeness, fragmentation, and so on) or in highlighting the existence of other particular issues which are to be addressed. We focus on the template "NPOV" which signals breaches on the fundamental policy of neutrality of Wikipedia articles and we show how and to what extent imposing such template on a page affects the production process and changes the nature and division of labor among participants. We find that intensity of editing increases immediately after the "NPOV" template appears. Moreover, articles that are treated most successfully, in the sense that "NPOV" disappears again relatively soon, are those articles which receive the attention of a limited group of editors. In this dimension at least the distribution of tasks in Wikipedia looks quite similar to what is know about the distribution in the FLOSS development process
Belle II Technical Design Report
The Belle detector at the KEKB electron-positron collider has collected
almost 1 billion Y(4S) events in its decade of operation. Super-KEKB, an
upgrade of KEKB is under construction, to increase the luminosity by two orders
of magnitude during a three-year shutdown, with an ultimate goal of 8E35 /cm^2
/s luminosity. To exploit the increased luminosity, an upgrade of the Belle
detector has been proposed. A new international collaboration Belle-II, is
being formed. The Technical Design Report presents physics motivation, basic
methods of the accelerator upgrade, as well as key improvements of the
detector.Comment: Edited by: Z. Dole\v{z}al and S. Un
Technical Proposal for FASER: ForwArd Search ExpeRiment at the LHC
FASER is a proposed small and inexpensive experiment designed to search for
light, weakly-interacting particles during Run 3 of the LHC from 2021-23. Such
particles may be produced in large numbers along the beam collision axis,
travel for hundreds of meters without interacting, and then decay to standard
model particles. To search for such events, FASER will be located 480 m
downstream of the ATLAS IP in the unused service tunnel TI12 and be sensitive
to particles that decay in a cylindrical volume with radius R=10 cm and length
L=1.5 m. FASER will complement the LHC's existing physics program, extending
its discovery potential to a host of new, light particles, with potentially
far-reaching implications for particle physics and cosmology.
This document describes the technical details of the FASER detector
components: the magnets, the tracker, the scintillator system, and the
calorimeter, as well as the trigger and readout system. The preparatory work
that is needed to install and operate the detector, including civil
engineering, transport, and integration with various services is also
presented. The information presented includes preliminary cost estimates for
the detector components and the infrastructure work, as well as a timeline for
the design, construction, and installation of the experiment.Comment: 82 pages, 62 figures; submitted to the CERN LHCC on 7 November 201
Generalized Points-to Graphs: A New Abstraction of Memory in the Presence of Pointers
Flow- and context-sensitive points-to analysis is difficult to scale; for
top-down approaches, the problem centers on repeated analysis of the same
procedure; for bottom-up approaches, the abstractions used to represent
procedure summaries have not scaled while preserving precision.
We propose a novel abstraction called the Generalized Points-to Graph (GPG)
which views points-to relations as memory updates and generalizes them using
the counts of indirection levels leaving the unknown pointees implicit. This
allows us to construct GPGs as compact representations of bottom-up procedure
summaries in terms of memory updates and control flow between them. Their
compactness is ensured by the following optimizations: strength reduction
reduces the indirection levels, redundancy elimination removes redundant memory
updates and minimizes control flow (without over-approximating data dependence
between memory updates), and call inlining enhances the opportunities of these
optimizations. We devise novel operations and data flow analyses for these
optimizations.
Our quest for scalability of points-to analysis leads to the following
insight: The real killer of scalability in program analysis is not the amount
of data but the amount of control flow that it may be subjected to in search of
precision. The effectiveness of GPGs lies in the fact that they discard as much
control flow as possible without losing precision (i.e., by preserving data
dependence without over-approximation). This is the reason why the GPGs are
very small even for main procedures that contain the effect of the entire
program. This allows our implementation to scale to 158kLoC for C programs
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