21,944 research outputs found
Improvising Linguistic Style: Social and Affective Bases for Agent Personality
This paper introduces Linguistic Style Improvisation, a theory and set of
algorithms for improvisation of spoken utterances by artificial agents, with
applications to interactive story and dialogue systems. We argue that
linguistic style is a key aspect of character, and show how speech act
representations common in AI can provide abstract representations from which
computer characters can improvise. We show that the mechanisms proposed
introduce the possibility of socially oriented agents, meet the requirements
that lifelike characters be believable, and satisfy particular criteria for
improvisation proposed by Hayes-Roth.Comment: 10 pages, uses aaai.sty, lingmacros.sty, psfig.st
Early aspects: aspect-oriented requirements engineering and architecture design
This paper reports on the third Early Aspects: Aspect-Oriented Requirements Engineering and Architecture Design Workshop, which has been held in Lancaster, UK, on March 21, 2004. The workshop included a presentation session and working sessions in which the particular topics on early aspects were discussed. The primary goal of the workshop was to focus on challenges to defining methodical software development processes for aspects from early on in the software life cycle and explore the potential of proposed methods and techniques to scale up to industrial applications
Wetting and particle adsorption in nanoflows
Molecular dynamics simulations are used to study the behavior of
closely-fitting spherical and ellipsoidal particles moving through a
fluid-filled cylinder at nanometer scales. The particle, the cylinder wall and
the fluid solvent are all treated as atomic systems, and special attention is
given to the effects of varying the wetting properties of the fluid. Although
the modification of the solid-fluid interaction leads to significant changes in
the microstructure of the fluid, its transport properties are found to be the
same as in bulk. Independently of the shape and relative size of the particle,
we find two distinct regimes as a function of the degree of wetting, with a
sharp transition between them. In the case of a highly-wetting suspending
fluid, the particle moves through the cylinder with an average axial velocity
in agreement with that obtained from the solution of the continuum Stokes
equations. In contrast, in the case of less-wetting fluids, only the early-time
motion of the particle is consistent with continuum dynamics. At later times,
the particle is eventually adsorbed onto the wall and subsequently executes an
intermittent stick-slip motion.We show that van der Walls forces are the
dominant contribution to the particle adsorption phenomenon and that depletion
forces are weak enough to allow, in the highly-wetting situation, an initially
adsorbed particle to spontaneously desorb
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Knowledge Management for Public Administrations: Technical Realizations of an Enterprise Attention Management System
The improvement of governments’ efficiency has gained great importance and validity especially in the current times of economic downturn. E-Government constitutes the most contemporary techno-managerial proposition in the track of possible interventions. The paper addresses, more specifically, empowerments necessitated by Public Administration (PA) organizations. Anchored on the needs of three real-life cases, the paper describes the conception and the realization of an IT artefact together with its methodological appeals aiming at improving information access and delivery and thus PAs’ decision making capacity. Our proposition constitutes a novel approach for managing users’ attention in knowledge intensive organizations which goes beyond informing a user about changes in relevant information towards proactively supporting the user to react on changes. The approach is based on an expressive attention model, which is realized by combining ECA (Event-Condition-Action) rules with ontologies. The technical realizations described in the paper constitute the underlying infrastructure of an Enterprise Attention Management System
Ultracold dipolar gases - a challenge for experiments and theory
We present a review of recent results concerning the physics of ultracold
trapped dipolar gases. In particular, we discuss the Bose-Einstein condensation
for dipolar Bose gases and the BCS transition for dipolar Fermi gases. In both
cases we stress the dominant role of the trap geometry in determining the
properties of the system. We present also results concerning bosonic dipolar
gases in optical lattices and the possibility of obtaining variety of different
quantum phases in such case. Finally, we analyze various possible routes
towards achieving ultracold dipolar gases.Comment: This paper is based on the lecture given by M. Lewenstein at the
Nobel Symposium ''Coherence and Condensation in Quantum Systems'',
Gothesburg, 4-7.12.200
Bacterial swarmer cells in confinement: A mesoscale hydrodynamic simulation study
A wide spectrum of Peritrichous bacteria undergo considerable physiological
changes when they are inoculated onto nutrition-rich surfaces and exhibit a
rapid and collective migration denoted as swarming. Thereby, the length of such
swarmer cells and their number of flagella increases substantially. In this
article, we investigated the properties of individual E. coli-type swarmer
cells confined between two parallel walls via mesoscale hydrodynamic
simulations, combining molecular dynamics simulations of the swarmer cell with
the multiparticle particle collision dynamics approach for the embedding fluid.
E. coli-type swarmer cells are three-times longer than their planktonic counter
parts, but their flagella density is comparable. By varying the wall
separation, we analyze the confinement effect on the flagella arrangement, on
the distribution of cells in the gap between the walls, and on the cell
dynamics. We find only a weak dependence of confinement on the bundle structure
and dynamics. The distribution of cells in the gap changes from a
geometry-dominated behavior for very narrow to fluid-dominated behavior for
wider gaps, where cells are preferentially located in the gap center for
narrower gaps and stay preferentially next to one of the walls for wider gaps.
Dynamically, the cells exhibit a wide spectrum of migration behaviors,
depending on their flagella bundle arrangement, and ranges from straight
swimming to wall rolling
Strategic Directions in Object-Oriented Programming
This paper has provided an overview of the field of object-oriented programming. After presenting a historical perspective and some major achievements in the field, four research directions were introduced: technologies integration, software components, distributed programming, and new paradigms. In general there is a need to continue research in traditional areas:\ud
(1) as computer systems become more and more complex, there is a need to further develop the work on architecture and design; \ud
(2) to support the development of complex systems, there is a need for better languages, environments, and tools; \ud
(3) foundations in the form of the conceptual framework and other theories must be extended to enhance the means for modeling and formal analysis, as well as for understanding future computer systems
The Effect of Columnar Disorder on the Superconducting Transition of a Type-II Superconductor in Zero Applied Magnetic Field
We investigate the effect of random columnar disorder on the superconducting
phase transition of a type-II superconductor in zero applied magnetic field
using numerical simulations of three dimensional XY and vortex loop models. We
consider both an unscreened model, in which the bare magnetic penetration
length is approximated as infinite, and a strongly screened model, in which the
magnetic penetration length is of order the vortex core radius. We consider
both equilibrium and dynamic critical exponents. We show that, as in the
disorder free case, the equilibrium transitions of the unscreened and strongly
screened models lie in the same universality class, however scaling is now
anisotropic. We find for the correlation length exponent , and
for the anisotropy exponent . We find different dynamic
critical exponents for the unscreened and strongly screened models.Comment: 30 pages 12 ps figure
Experimental study of the transport of coherent interacting matter-waves in a 1D random potential induced by laser speckle
We present a detailed analysis of the 1D expansion of a coherent interacting
matterwave (a Bose-Einstein condensate) in the presence of disorder. A 1D
random potential is created via laser speckle patterns. It is carefully
calibrated and the self-averaging properties of our experimental system are
discussed. We observe the suppression of the transport of the BEC in the random
potential. We discuss the scenario of disorder-induced trapping taking into
account the radial extension in our experimental 3D BEC and we compare our
experimental results with the theoretical predictions
Bose-Einstein condensation in trapped dipolar gases
We discuss Bose-Einstein condensation in a trapped gas of bosonic particles
interacting dominantly via dipole-dipole forces. We find that in this case the
mean-field interparticle interaction and, hence, the stability diagram are
governed by the trapping geometry. Possible physical realisations include
ultracold heteronuclear molecules, or atoms with laser induced electric dipole
moments.Comment: 4 pages, 4 figure
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