903 research outputs found
Evaluating Singleplayer and Multiplayer in Human Computation Games
Human computation games (HCGs) can provide novel solutions to intractable
computational problems, help enable scientific breakthroughs, and provide
datasets for artificial intelligence. However, our knowledge about how to
design and deploy HCGs that appeal to players and solve problems effectively is
incomplete. We present an investigatory HCG based on Super Mario Bros. We used
this game in a human subjects study to investigate how different social
conditions---singleplayer and multiplayer---and scoring
mechanics---collaborative and competitive---affect players' subjective
experiences, accuracy at the task, and the completion rate. In doing so, we
demonstrate a novel design approach for HCGs, and discuss the benefits and
tradeoffs of these mechanics in HCG design.Comment: 10 pages, 4 figures, 2 table
A Framework for Exploring and Evaluating Mechanics in Human Computation Games
Human computation games (HCGs) are a crowdsourcing approach to solving
computationally-intractable tasks using games. In this paper, we describe the
need for generalizable HCG design knowledge that accommodates the needs of both
players and tasks. We propose a formal representation of the mechanics in HCGs,
providing a structural breakdown to visualize, compare, and explore the space
of HCG mechanics. We present a methodology based on small-scale design
experiments using fixed tasks while varying game elements to observe effects on
both the player experience and the human computation task completion. Finally
we discuss applications of our framework using comparisons of prior HCGs and
recent design experiments. Ultimately, we wish to enable easier exploration and
development of HCGs, helping these games provide meaningful player experiences
while solving difficult problems.Comment: 11 pages, 5 figure
Einkommen und Armut von Familien und älteren Menschen
Die Einkommensposition von Familien hängt nicht nur von der Erwerbssituation der Haushaltsmitglieder ab, sondern auch vom Alter der Kinder. Dies zeigt eine Auswertung des vom DIW Berlin in Zusammenarbeit mit Infratest Sozialforschung erhobenen Sozio-oekonomischen Panels (SOEP). Zusammenlebende Paare mit Kindern kommen danach - gemessen an der gesamten Bevölkerung - auf ein durchschnittliches Einkommen. Das Armutsrisiko ist jedoch umso höher, je kleiner das jüngste Kind ist. Dieses Muster gilt auch für Alleinerziehende, die generell ein überdurchschnittliches Risiko für Einkommensarmut aufweisen, das sich zudem seit Mitte der 80er Jahre weiter erhöht hat. Die Einkommensposition der älteren Menschen in Deutschland hat sich hingegen in den vergangenen 20 Jahren deutlich verbessert. Abgesehen von alleinstehenden älteren Frauen ist die Armutsrate bei älteren Menschen geringer als in der Gesamtbevölkerung. Die in diesem Bericht angewandten Messverfahren werden im Wesentlichen auch im Armuts- und Reichtumsbericht der Bundesregierung verwendet.
Enlarged infarct volume and loss of BDNF mRNA induction following brain ischemia in mice lacking FGF-2
FGF-2, a potent multifunctional and neurotrophic growth factor, is widely expressed in the brain and upregulated in cerebral ischemia. Previous studies have shown that intraventricularly or systemically administered FGF-2 reduces the size of cerebral infarcts. Whether endogenous FGF-2 is beneficial for the outcome of cerebral ischemia has not been investigated. We have used mice with a null mutation of the fgf2 gene to explore the relevance of endogenous FGF-2 in brain ischemia. Focal cerebral ischemia was produced by occlusion of the middle cerebral artery (MCAO). We found a 75% increase in infarct volume in fgf2 knock-out mice versus wild type littermates (P < 0.05). This difference in the extent of ischemic damage was observed after 24 h, and correlated with decreased viability in fgf2 mutant mice following MCA occlusion. Increased infarct volume in fgf2 null mice was associated with a loss of induction in hippocampal BDNF and trkB mRNA expression. These findings indicate that signaling through trkB may contribute to ameliorating brain damage following ischemia and that bdnf and trkB may be target genes of FGF-2. Together, our data provide the first evidence that endogenous FGF-2 is important in coping with ischemic brain damage suggesting fgf2 as one crucial target gene for new therapeutic strategies in brain ischemia
High energy astroparticle physics for high school students
The questions about the origin and type of cosmic particles are not only
fascinating for scientists in astrophysics, but also for young enthusiastic
high school students. To familiarize them with research in astroparticle
physics, the Pierre Auger Collaboration agreed to make 1% of its data publicly
available. The Pierre Auger Observatory investigates cosmic rays at the highest
energies and consists of more than 1600 water Cherenkov detectors, located near
Malarg\"{u}e, Argentina. With publicly available data from the experiment,
students can perform their own hands-on analysis. In the framework of a
so-called Astroparticle Masterclass organized alongside the context of the
German outreach network Netzwerk Teilchenwelt, students get a valuable insight
into cosmic ray physics and scientific research concepts. We present the
project and experiences with students.Comment: 8 pages, 5 figures, Proceedings of the 34th International Cosmic Ray
Conference (ICRC2015), The Hague, The Netherlands, PoS(ICRC2015)30
Editorial: Towards a Unifying Pan-Arctic Perspective of the Contemporary and Future Arctic Ocean
An international symposium addressing pan-Arctic perspectives of the marine ecosystems of
the Arctic Ocean took place in October 2017 and this editorial introduces the publications that
derived from the conference. The symposium focused in particular upon physical forcing and
biogeochemical cycling in surface waters of the Arctic Ocean, connectivity between surface and
deep waters in the central basins and adjacent slopes and the ecology of the lesser-known shelf
ecosystems. The symposium was the fourth in a sequence that has pan-Arctic integrations of Arctic
Ocean ecosystems at its core. The series started in 2002 and its first volume was published under
the title Structure and function of contemporary food webs on Arctic shelves (Wassmann, 2006). At
the 2002-meeting, a suite of marine Arctic researchers from the main nations that work in the
Arctic Ocean started applying the now-ubiquitous term pan-Arctic. The term underlined that the
applied research goals and directions were more than a circumarctic perspective, but distinctly
considered the entire expanse of the Arctic Ocean. Based upon this exercise, increased interest
in the Arctic and some of the scientific endeavors of the 4th International Polar Year central
projects and key oceanographers operating in the pan-Arctic region convened at the 2nd pan-Arctic
integration symposium, entitled Arctic Marine Ecosystems in an Era of Rapid Climate Change in
2009 (Wassmann, 2011). After a decade of pan-Arctic research and building upon the foundation
presented in Wassmann (2006, 2011) a 3rd conference was initiated in 2012, entitled Overarching
perspectives of contemporary and future ecosystems in the Arctic Ocean (Wassmann, 2015).
This Research Topic brings together 13 publications from the 4th pan-arctic integration
symposium held in 2017, entitled Toward a Unifying Pan-Arctic Perspective of the Contemporary
and Future Arctic Ocean. We, the editors of the Research Topic, are delighted with the breadth,
quality and diversity of the papers. We introduce the essence of the publications under three,
summarizing headlines
• Physical connectivity, yet regionality
• What shapes pan-Arctic primary production
• The fate of production.
Toward the end we incorporate the knowledge presented in this volume into the overall progress.
and status of pan-Arctic marine ecosystem integration that has been achieved, so far, through the
four pan-Arctic integration symposia
Learning Set Functions that are Sparse in Non-Orthogonal Fourier Bases
Many applications of machine learning on discrete domains, such as learning
preference functions in recommender systems or auctions, can be reduced to
estimating a set function that is sparse in the Fourier domain. In this work,
we present a new family of algorithms for learning Fourier-sparse set
functions. They require at most queries (set function
evaluations), under mild conditions on the Fourier coefficients, where is
the size of the ground set and the number of non-zero Fourier coefficients.
In contrast to other work that focused on the orthogonal Walsh-Hadamard
transform, our novel algorithms operate with recently introduced non-orthogonal
Fourier transforms that offer different notions of Fourier-sparsity. These
naturally arise when modeling, e.g., sets of items forming substitutes and
complements. We demonstrate effectiveness on several real-world applications
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