67,542 research outputs found
Modelling data intensive web sites with OntoWeaver
This paper illustrates the OntoWeaver modelling approach, which relies on a set of comprehensive site ontologies to model all aspects of data intensive web sites and thus offers high level support for the design and development of data-intensive web sites. In particular, the OntoWeaver site
ontologies comprise two components: a site view ontology and a presentation ontology. The site view ontology provides meta-models to allow for the composition of sophisticated site views, which allow end users to navigate and manipulate the underlying domain databases. The presentation ontology abstracts the look and feel for site views and makes it possible for the visual appearance and layout to be specified at a high level of abstractio
The Dynamics of Nestedness Predicts the Evolution of Industrial Ecosystems
In economic systems, the mix of products that countries make or export has
been shown to be a strong leading indicator of economic growth. Hence, methods
to characterize and predict the structure of the network connecting countries
to the products that they export are relevant for understanding the dynamics of
economic development. Here we study the presence and absence of industries at
the global and national levels and show that these networks are significantly
nested. This means that the less filled rows and columns of these networks'
adjacency matrices tend to be subsets of the fuller rows and columns. Moreover,
we show that nestedness remains relatively stable as the matrices become more
filled over time and that this occurs because of a bias for industries that
deviate from the networks' nestedness to disappear, and a bias for the missing
industries that reduce nestedness to appear. This makes the appearance and
disappearance of individual industries in each location predictable. We
interpret the high level of nestedness observed in these networks in the
context of the neutral model of development introduced by Hidalgo and Hausmann
(2009). We show that, for the observed fills, the model can reproduce the high
level of nestedness observed in these networks only when we assume a high level
of heterogeneity in the distribution of capabilities available in countries and
required by products. In the context of the neutral model, this implies that
the high level of nestedness observed in these economic networks emerges as a
combination of both, the complementarity of inputs and heterogeneity in the
number of capabilities available in countries and required by products. The
stability of nestedness in industrial ecosystems, and the predictability
implied by it, demonstrates the importance of the study of network properties
in the evolution of economic networks.Comment: 26 page
Exploring the Design Space of Robot Appearance and Behavior in an Attention-Seeking Living Room Scenario for a Robot Companion
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Aximo: automated axiomatic reasoning for information update
Aximo is a software written in C++ that verifies epistemic properties of dynamic scenarios in multi-agent systems. The underlying logic of our tool is based on the algebraic axiomatics of Dynamic Epistemic Logic. We also present a new theoretical result: the worst case complexity of the verification problem of Aximo
Classical Knowledge for Quantum Security
We propose a decision procedure for analysing security of quantum
cryptographic protocols, combining a classical algebraic rewrite system for
knowledge with an operational semantics for quantum distributed computing. As a
test case, we use our procedure to reason about security properties of a
recently developed quantum secret sharing protocol that uses graph states. We
analyze three different scenarios based on the safety assumptions of the
classical and quantum channels and discover the path of an attack in the
presence of an adversary. The epistemic analysis that leads to this and similar
types of attacks is purely based on our classical notion of knowledge.Comment: extended abstract, 13 page
No Time to Move: Motion, Painting and Temporal Experience
This paper is concerned with the senses in which paintings do and do not depict various temporal phenomena, such as motion, stasis and duration. I begin by explaining the popular – though not uncontroversial – assumption that depiction, as a pictorial form of representation, is a matter of an experiential resemblance between the pictorial representation and that which it is a depiction of. Given this assumption, I illustrate a tension between two plausible claims: that paintings do not depict motion in the sense that video recordings do, and that paintings do not merely depict objects but may depict those objects as engaged in various activities, such as moving. To resolve the tension, I demonstrate that we need to recognise an ambiguity in talk of the appearance of motion, and distinguish between the depiction of motion and the depiction of an object as an object that is moving. Armed with this distinction, I argue that there is an important sense in which paintings depict neither motion, duration, nor – perhaps more controversially – stasis
Fundamental structures of dynamic social networks
Social systems are in a constant state of flux with dynamics spanning from
minute-by-minute changes to patterns present on the timescale of years.
Accurate models of social dynamics are important for understanding spreading of
influence or diseases, formation of friendships, and the productivity of teams.
While there has been much progress on understanding complex networks over the
past decade, little is known about the regularities governing the
micro-dynamics of social networks. Here we explore the dynamic social network
of a densely-connected population of approximately 1000 individuals and their
interactions in the network of real-world person-to-person proximity measured
via Bluetooth, as well as their telecommunication networks, online social media
contacts, geo-location, and demographic data. These high-resolution data allow
us to observe social groups directly, rendering community detection
unnecessary. Starting from 5-minute time slices we uncover dynamic social
structures expressed on multiple timescales. On the hourly timescale, we find
that gatherings are fluid, with members coming and going, but organized via a
stable core of individuals. Each core represents a social context. Cores
exhibit a pattern of recurring meetings across weeks and months, each with
varying degrees of regularity. Taken together, these findings provide a
powerful simplification of the social network, where cores represent
fundamental structures expressed with strong temporal and spatial regularity.
Using this framework, we explore the complex interplay between social and
geospatial behavior, documenting how the formation of cores are preceded by
coordination behavior in the communication networks, and demonstrating that
social behavior can be predicted with high precision.Comment: Main Manuscript: 16 pages, 4 figures. Supplementary Information: 39
pages, 34 figure
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