201 research outputs found
Body Language Without a Body: Nonverbal Communication in Technology Mediated Settings
Humans are wired for face-to-face interaction because this was the only possible and available setting during the long evolutionary process that has led to Homo Sapiens. At the moment an increasingly significant fraction of our interactions take place in technology mediated settings, it is important to investigate how such a wiring - mainly corresponding to neural processes - reacts and adapts to them. This talk focuses in particular on how nonverbal communication - one of the main channels through which people convey socially and psychologically relevant information - plays a role in settings where natural nonverbal cues (facial expressions, vocalizations, gestures, etc.) are no longer available. Such an issue is important not only from a technological point of view (it can help to design interaction and communication technologies that better address human needs), but also from a societal one (it can help to understand major phenomena such as cyberbullyism and virality)
Correlation Functions of Harish-Chandra Integrals over the Orthogonal and the Symplectic Groups
The Harish-Chandra correlation functions, i.e. integrals over compact groups
of invariant monomials prod tr{X^{p_1} Omega Y^{q_1} Omega^dagger X^{p_2} ...
with the weight exp tr{X Omega Y Omega^dagger} are computed for the orthogonal
and symplectic groups. We proceed in two steps. First, the integral over the
compact group is recast into a Gaussian integral over strictly upper triangular
complex matrices (with some additional symmetries), supplemented by a summation
over the Weyl group. This result follows from the study of loop equations in an
associated two-matrix integral and may be viewed as the adequate version of
Duistermaat-Heckman's theorem for our correlation function integrals. Secondly,
the Gaussian integration over triangular matrices is carried out and leads to
compact determinantal expressions.Comment: 58 pages; Acknowledgements added; small corrections in appendix A;
minor changes & Note Adde
Shaping Robot Gestures to Shape Users' Perception: the Effect of Amplitude and Speed on Godspeed Ratings
This work analyses the relationship between the way robots gesture and the way those gestures are perceived by human users. In particular, this work shows how modifying the amplitude and speed of a gesture affect the Godspeed scores given to those gestures, by means of an experiment involving 45 stimuli and 30 observers. The results suggest that shaping gestures aimed at manifesting the inner state of the robot (e.g., cheering or showing disappointment) tends to change the perception of Animacy (the dimension that accounts for how driven by endogenous factors the robot is perceived to be), while shaping gestures aimed at achieving an interaction effect (e.g., engaging and disengaging) tends to change the perception of Anthropomorphism, Likeability and Perceived Safety (the dimensions that account for the social aspects of the perception)
The Composition of Cosmic Rays at the Knee
The observation of a small change in spectral slope, or 'knee' in the fluxes
of cosmic rays near energies 10^15 eV has caused much speculation since its
discovery over 40 years ago. The origin of this feature remains unknown. A
small workshop to review some modern experimental measurements of this region
was held at the Adler Planetarium in Chicago, USA in June 2000. This paper
summarizes the results presented at this workshop and the discussion of their
interpretation in the context of hadronic models of atmospheric airshowers.Comment: 36 pages, 10 figure
Cosmological parameters from SDSS and WMAP
We measure cosmological parameters using the three-dimensional power spectrum
P(k) from over 200,000 galaxies in the Sloan Digital Sky Survey (SDSS) in
combination with WMAP and other data. Our results are consistent with a
``vanilla'' flat adiabatic Lambda-CDM model without tilt (n=1), running tilt,
tensor modes or massive neutrinos. Adding SDSS information more than halves the
WMAP-only error bars on some parameters, tightening 1 sigma constraints on the
Hubble parameter from h~0.74+0.18-0.07 to h~0.70+0.04-0.03, on the matter
density from Omega_m~0.25+/-0.10 to Omega_m~0.30+/-0.04 (1 sigma) and on
neutrino masses from <11 eV to <0.6 eV (95%). SDSS helps even more when
dropping prior assumptions about curvature, neutrinos, tensor modes and the
equation of state. Our results are in substantial agreement with the joint
analysis of WMAP and the 2dF Galaxy Redshift Survey, which is an impressive
consistency check with independent redshift survey data and analysis
techniques. In this paper, we place particular emphasis on clarifying the
physical origin of the constraints, i.e., what we do and do not know when using
different data sets and prior assumptions. For instance, dropping the
assumption that space is perfectly flat, the WMAP-only constraint on the
measured age of the Universe tightens from t0~16.3+2.3-1.8 Gyr to
t0~14.1+1.0-0.9 Gyr by adding SDSS and SN Ia data. Including tensors, running
tilt, neutrino mass and equation of state in the list of free parameters, many
constraints are still quite weak, but future cosmological measurements from
SDSS and other sources should allow these to be substantially tightened.Comment: Minor revisions to match accepted PRD version. SDSS data and ppt
figures available at http://www.hep.upenn.edu/~max/sdsspars.htm
The PHENIX Experiment at RHIC
The physics emphases of the PHENIX collaboration and the design and current
status of the PHENIX detector are discussed. The plan of the collaboration for
making the most effective use of the available luminosity in the first years of
RHIC operation is also presented.Comment: 5 pages, 1 figure. Further details of the PHENIX physics program
available at http://www.rhic.bnl.gov/phenix
The exposure of the hybrid detector of the Pierre Auger Observatory
The Pierre Auger Observatory is a detector for ultra-high energy cosmic rays.
It consists of a surface array to measure secondary particles at ground level
and a fluorescence detector to measure the development of air showers in the
atmosphere above the array. The "hybrid" detection mode combines the
information from the two subsystems. We describe the determination of the
hybrid exposure for events observed by the fluorescence telescopes in
coincidence with at least one water-Cherenkov detector of the surface array. A
detailed knowledge of the time dependence of the detection operations is
crucial for an accurate evaluation of the exposure. We discuss the relevance of
monitoring data collected during operations, such as the status of the
fluorescence detector, background light and atmospheric conditions, that are
used in both simulation and reconstruction.Comment: Paper accepted by Astroparticle Physic
Intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a US Great Plains' precipitation gradient: implications for grassland restoration with climate change
Citation: Johnson, L. C., Olsen, J. T., Tetreault, H., DeLaCruz, A., Bryant, J., Morgan, T. J., . . . Maricle, B. R. (2015). Intraspecific variation of a dominant grass and local adaptation in reciprocal garden communities along a US Great Plains' precipitation gradient: implications for grassland restoration with climate change. Evolutionary Applications, 8(7), 705-723. doi:10.1111/eva.12281Identifying suitable genetic stock for restoration often employs a best guess' approach. Without adaptive variation studies, restoration may be misguided. We test the extent to which climate in central US grasslands exerts selection pressure on a foundation grass big bluestem (Andropogon gerardii), widely used in restorations, and resulting in local adaptation. We seeded three regional ecotypes of A.gerardii in reciprocal transplant garden communities across 1150km precipitation gradient. We measured ecological responses over several timescales (instantaneous gas exchange, medium-term chlorophyll absorbance, and long-term responses of establishment and cover) in response to climate and biotic factors and tested if ecotypes could expand range. The ecotype from the driest region exhibited greatest cover under low rainfall, suggesting local adaptation under abiotic stress. Unexpectedly, no evidence for cover differences between ecotypes exists at mesic sites where establishment and cover of all ecotypes were low, perhaps due to strong biotic pressures. Expression of adaptive differences is strongly environment specific. Given observed adaptive variation, the most conservative restoration strategy would be to plant the local ecotype, especially in drier locations. With superior performance of the most xeric ecotype under dry conditions and predicted drought, this ecotype may migrate eastward, naturally or with assistance in restorations
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