10,155 research outputs found
Extensible sparse functional arrays with circuit parallelism
A longstanding open question in algorithms and data structures is the time and space complexity of pure functional arrays. Imperative arrays provide update and lookup operations that require constant time in the RAM theoretical model, but it is conjectured that there does not exist a RAM algorithm that achieves the same complexity for functional arrays, unless restrictions are placed on the operations. The main result of this paper is an algorithm that does achieve optimal unit time and space complexity for update and lookup on functional arrays. This algorithm does not run on a RAM, but instead it exploits the massive parallelism inherent in digital circuits. The algorithm also provides unit time operations that support storage management, as well as sparse and extensible arrays. The main idea behind the algorithm is to replace a RAM memory by a tree circuit that is more powerful than the RAM yet has the same asymptotic complexity in time (gate delays) and size (number of components). The algorithm uses an array representation that allows elements to be shared between many arrays with only a small constant factor penalty in space and time. This system exemplifies circuit parallelism, which exploits very large numbers of transistors per chip in order to speed up key algorithms. Extensible Sparse Functional Arrays (ESFA) can be used with both functional and imperative programming languages. The system comprises a set of algorithms and a circuit specification, and it has been implemented on a GPGPU with good performance
Light Mesons from Heavy B and Hyperon Decays
Decays of heavy mesons and of heavy hyperons are used to provide tests of the
standard model and information about new mixing schemes for the and
mesons. These include the two body decays and
, and , semileptonic decays, and properties of radially
excited mesons.Comment: Four pages. Talk given at the Fifth International Conference on
Hyperons, Charm and Beauty Hadrons, Vancouver, BC, Canada, July 25-29, 200
A New State of Baryonium
The recent discovery of a narrow resonance in the decay is described as a zero baryon number,
``deuteron-like singlet '' state. The difference in binding energy
of the deuteron (-2.225 MeV) and of the new state (-17.5 MeV) can be accounted
for in a simple potential model with a confining
interaction.Comment: 7 page
The Sound Manifesto
Computing practice today depends on visual output to drive almost all user
interaction. Other senses, such as audition, may be totally neglected, or used
tangentially, or used in highly restricted specialized ways. We have excellent
audio rendering through D-A conversion, but we lack rich general facilities for
modeling and manipulating sound comparable in quality and flexibility to
graphics. We need co-ordinated research in several disciplines to improve the
use of sound as an interactive information channel.
Incremental and separate improvements in synthesis, analysis, speech
processing, audiology, acoustics, music, etc. will not alone produce the
radical progress that we seek in sonic practice. We also need to create a new
central topic of study in digital audio research. The new topic will assimilate
the contributions of different disciplines on a common foundation. The key
central concept that we lack is sound as a general-purpose information channel.
We must investigate the structure of this information channel, which is driven
by the co-operative development of auditory perception and physical sound
production. Particular audible encodings, such as speech and music, illuminate
sonic information by example, but they are no more sufficient for a
characterization than typography is sufficient for a characterization of visual
information.Comment: To appear in the conference on Critical Technologies for the Future
of Computing, part of SPIE's International Symposium on Optical Science and
Technology, 30 July to 4 August 2000, San Diego, C
BowScribe: Supporting the violinist's performance model
Musicians often learn about their vision of a
piece through practicing it and listening to recordings. However,
this does not always free the player to develop his or her own
interpretation of the piece, especially when technique is lacking. We
have developed software, the BowScribe markup language, that supports
a violinist in creating a ``performance model'' of a piece currently
beyond his or her playing skills, by allowing the player fine control
over tempo, volume, and articulation, including playing of chords, at
a level of expressiveness and flexibility that is significantly beyond
the MIDI playback modes of popular music notation software. BowScribe
has been used by the first author (who was trained as a prfessional
violinist) to create a model of the entire Bach Chaconne (edited by
Glamian), a long and demanding piece of music for solo violin that has
many phrases that span groups of chords as well as melodic passages.
The markup language specified chords to be rolled in two classic ways,
as well as a wide variety of other strokes, including greater volume
for individual notes in long slurs and small but essential variations
in tempo
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