47,681 research outputs found
Effective Labor Arbitration: The Impartial Chairmanship of the Full-Fashioned Hosiery Industry by Thomas Kennedy
The cognitive organization of music knowledge: a clinical analysis
Despite much recent interest in the clinical neuroscience of music processing, the cognitive organization of music as a domain of non-verbal knowledge has been little studied. Here we addressed this issue systematically in two expert musicians with clinical diagnoses of semantic dementia and Alzheimer’s disease, in comparison with a control group of healthy expert musicians. In a series of neuropsychological experiments, we investigated associative knowledge of musical compositions (musical objects), musical emotions, musical instruments (musical sources) and music notation (musical symbols). These aspects of music knowledge were assessed in relation to musical perceptual abilities and extra-musical neuropsychological functions. The patient with semantic dementia showed relatively preserved recognition of musical compositions and musical symbols despite severely impaired recognition of musical emotions and musical instruments from sound. In contrast, the patient with Alzheimer’s disease showed impaired recognition of compositions, with somewhat better recognition of composer and musical era, and impaired comprehension of musical symbols, but normal recognition of musical emotions and musical instruments from sound. The findings suggest that music knowledge is fractionated, and superordinate musical knowledge is relatively more robust than knowledge of particular music. We propose that music constitutes a distinct domain of non-verbal knowledge but shares certain cognitive organizational features with other brain knowledge systems. Within the domain of music knowledge, dissociable cognitive mechanisms process knowledge derived from physical sources and the knowledge of abstract musical entities
The Cosmopolitan Tradition: A Noble but Flawed Ideal
Book Review of The Cosmopolitan Tradition: A Noble but Flawed Ideal. By Nussbaum Martha C.
Dynamical virial masses of Lyman-break galaxy haloes at z=3
We improve on our earlier dynamical estimate of the virial masses of the
haloes of Lyman-break galaxies (LBGs) at redshift z=3 by accounting for the
effects of seeing, slit width, and observational uncertainties. From an
analysis of the small number of available rotation curves for LBGs we determine
a relation Vc7=(1.9+/-0.2)sigma between circular velocity at a radius of 7kpc,
and central line velocity width. We use this relation to transform the measured
velocity widths of 32 LBGs to the distribution of circular velocities, for the
population of LBGs brighter than R=25.5. We compare this distribution against
the predicted distribution for the 'massive-halo' model in which LBGs pinpoint
all of the highest mass dark matter haloes at that epoch. The observed LBG
circular velocities are smaller than the predicted circular velocities by a
factor >1.4+/-0.15. This is a lower limit as we have ignored any increase of
circular velocity caused by baryonic dissipation. The massive-halo model
predicts a median halo virial mass of 10^12.3 Msol, and a small spread of
circular velocities. Our median estimated dynamical mass is <10^(11.6+/-0.3)
Msol, which is significantly smaller; furthermore, the spread of our circular
velocities is much larger than the massive-halo prediction. These results are
consistent with a picture which leaves some of the most-massive haloes
available for occupation by other populations which do not meet the LBG
selection criteria. The median halo mass recently estimated by Adelberger et
al. from the measured clustering of LBGs is 10^(11.86+/-0.3) Msol. Our
dynamical analysis appears to favour lower masses and to be more in line with
the median mass predicted by the collisional starburst model of Somerville et
al., of 10^11.3 Msol. [abridged]Comment: 6 pages, 5 figures, MNRAS Letters, Accepte
Scalable Successive-Cancellation Hardware Decoder for Polar Codes
Polar codes, discovered by Ar{\i}kan, are the first error-correcting codes
with an explicit construction to provably achieve channel capacity,
asymptotically. However, their error-correction performance at finite lengths
tends to be lower than existing capacity-approaching schemes. Using the
successive-cancellation algorithm, polar decoders can be designed for very long
codes, with low hardware complexity, leveraging the regular structure of such
codes. We present an architecture and an implementation of a scalable hardware
decoder based on this algorithm. This design is shown to scale to code lengths
of up to N = 2^20 on an Altera Stratix IV FPGA, limited almost exclusively by
the amount of available SRAM
- …