3,382 research outputs found
Should I Bug You? Identifying Domain Experts in Software Projects Using Code Complexity Metrics
In any sufficiently complex software system there are experts, having a
deeper understanding of parts of the system than others. However, it is not
always clear who these experts are and which particular parts of the system
they can provide help with. We propose a framework to elicit the expertise of
developers and recommend experts by analyzing complexity measures over time.
Furthermore, teams can detect those parts of the software for which currently
no, or only few experts exist and take preventive actions to keep the
collective code knowledge and ownership high. We employed the developed
approach at a medium-sized company. The results were evaluated with a survey,
comparing the perceived and the computed expertise of developers. We show that
aggregated code metrics can be used to identify experts for different software
components. The identified experts were rated as acceptable candidates by
developers in over 90% of all cases
Content and popularity analysis of Tor hidden services
Tor hidden services allow running Internet services while protecting the
location of the servers. Their main purpose is to enable freedom of speech even
in situations in which powerful adversaries try to suppress it. However,
providing location privacy and client anonymity also makes Tor hidden services
an attractive platform for every kind of imaginable shady service. The ease
with which Tor hidden services can be set up has spurred a huge growth of
anonymously provided Internet services of both types. In this paper we analyse
the landscape of Tor hidden services. We have studied Tor hidden services after
collecting 39824 hidden service descriptors on 4th of Feb 2013 by exploiting
protocol and implementation flaws in Tor: we scanned them for open ports; in
the case of HTTP services, we analysed and classified their content. We also
estimated the popularity of hidden services by looking at the request rate for
hidden service descriptors by clients. We found that while the content of Tor
hidden services is rather varied, the most popular hidden services are related
to botnets.Comment: 6 pages, 3 figures, 2 table
On the evolution of the density pdf in strongly self-gravitating systems
The time evolution of the probability density function (PDF) of the mass
density is formulated and solved for systems in free-fall using a simple
appoximate function for the collapse of a sphere. We demonstrate that a
pressure-free collapse results in a power-law tail on the high-density side of
the PDF. The slope quickly asymptotes to the functional form
for the (volume-weighted) PDF and
for the corresponding mass-weighted
distribution. From the simple approximation of the PDF we derive analytic
descriptions for mass accretion, finding that dynamically quiet systems with
narrow density PDFs lead to retarded star formation and low star formation
rates. Conversely, strong turbulent motions that broaden the PDF accelerate the
collapse causing a bursting mode of star formation. Finally, we compare our
theoretical work with observations. The measured star formation rates are
consistent with our model during the early phases of the collapse. Comparison
of observed column density PDFs with those derived from our model suggests that
observed star-forming cores are roughly in free-fall.Comment: accepted for publication, 13 page
Economic incentive patterns and their application to ad hoc networks
While research about cooperation incentives for mobile ad hoc
networks (MANETs) is done only for a relative short period,
there exists tremendous knowledge in the economic and social
areas. Based on a new categorization of incentive patterns, we
examine the relevant properties of each pattern and
demonstrate their respective design alternatives and occurring
challenges for the application to ad hoc networks. With a focus
on trade based patterns, we found that negotiation about actions
proves to be very complex or inefficient in MANETs. Another
approach, the introduction of an artificial currency,
also implies several problems like how to equip the entities
with means of payment and how to secure liquidity. As a novelty,
we introduce a new kind of incentive pattern following the
concept of company shares.
It suits well for MANETs because it can be shown that through
the creation of individual currencies the above mentioned
problems disappear
462 Machine Translation Systems for Europe
We built 462 machine translation systems for all language pairs of the Acquis Communautaire corpus. We report and analyse the performance of these system, and compare them against pivot translation and a number of system combination methods (multi-pivot, multisource) that are possible due to the available systems.JRC.G.2-Global security and crisis managemen
ProGS: Property Graph Shapes Language (Extended Version)
Property graphs constitute data models for representing knowledge graphs.
They allow for the convenient representation of facts, including facts about
facts, represented by triples in subject or object position of other triples.
Knowledge graphs such as Wikidata are created by a diversity of contributors
and a range of sources leaving them prone to two types of errors. The first
type of error, falsity of facts, is addressed by property graphs through the
representation of provenance and validity, making triples occur as first-order
objects in subject position of metadata triples. The second type of error,
violation of domain constraints, has not been addressed with regard to property
graphs so far. In RDF representations, this error can be addressed by shape
languages such as SHACL or ShEx, which allow for checking whether graphs are
valid with respect to a set of domain constraints. Borrowing ideas from the
syntax and semantics definitions of SHACL, we design a shape language for
property graphs, ProGS, which allows for formulating shape constraints on
property graphs including their specific constructs, such as edges with
identities and key-value annotations to both nodes and edges. We define a
formal semantics of ProGS, investigate the resulting complexity of validating
property graphs against sets of ProGS shapes, compare with corresponding
results for SHACL, and implement a prototypical validator that utilizes answer
set programming
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