2,451 research outputs found
A Bibliography on Fuzzy Automata, Grammars and Lanuages
This bibliography contains references to papers on fuzzy formal languages, the generation of fuzzy languages by means of fuzzy grammars, the recognition of fuzzy languages by fuzzy automata and machines, as well as some applications of fuzzy set theory to syntactic pattern recognition, linguistics and natural language processing
A logic for application level QoS
Service Oriented Computing (SOC) has been proposed as a paradigm to describe computations of applications on wide area distributed systems. Awareness of Quality of Service (QoS) is emerging as a new exigency in both design and implementation of SOC applications.
We do not refer to QoS aspects related to low-level performance and focus on those high-level non-functional features perceived by end-users as application dependent requirements, e.g., the price of a given service, or the payment mode, or else the availability of a resource (e.g., a file in a given format).
In this paper we present a logic which includes mechanisms to consider the three main dimensions of systems, namely their structure, behaviour and QoS aspects. The evaluation of a formula is a value of a constraint-semiring and not just a boolean value expressing whether or not the formula holds. This permits to express not only topological and temporal properties but also QoS properties of systems.
The logic is interpreted on SHReQ, a formal framework for specifying systems that handles abstract high-level QoS aspects combining Synchronised Hyperedge Replacement with constraint-semirings
Visual Analytics for Understanding Draco's Knowledge Base
Draco has been developed as an automated visualization recommendation system
formalizing design knowledge as logical constraints in ASP (Answer-Set
Programming). With an increasing set of constraints and incorporated design
knowledge, even visualization experts lose overview in Draco and struggle to
retrace the automated recommendation decisions made by the system. Our paper
proposes an Visual Analytics (VA) approach to visualize and analyze Draco's
constraints. Our VA approach is supposed to enable visualization experts to
accomplish identified tasks regarding the knowledge base and support them in
better understanding Draco. We extend the existing data extraction strategy of
Draco with a data processing architecture capable of extracting features of
interest from the knowledge base. A revised version of the ASP grammar provides
the basis for this data processing strategy. The resulting incorporated and
shared features of the constraints are then visualized using a hypergraph
structure inside the radial-arranged constraints of the elaborated
visualization. The hierarchical categories of the constraints are indicated by
arcs surrounding the constraints. Our approach is supposed to enable
visualization experts to interactively explore the design rules' violations
based on highlighting respective constraints or recommendations. A qualitative
and quantitative evaluation of the prototype confirms the prototype's
effectiveness and value in acquiring insights into Draco's recommendation
process and design constraints.Comment: To be presented at VIS 202
A Component-oriented Framework for Autonomous Agents
The design of a complex system warrants a compositional methodology, i.e.,
composing simple components to obtain a larger system that exhibits their
collective behavior in a meaningful way. We propose an automaton-based paradigm
for compositional design of such systems where an action is accompanied by one
or more preferences. At run-time, these preferences provide a natural fallback
mechanism for the component, while at design-time they can be used to reason
about the behavior of the component in an uncertain physical world. Using
structures that tell us how to compose preferences and actions, we can compose
formal representations of individual components or agents to obtain a
representation of the composed system. We extend Linear Temporal Logic with two
unary connectives that reflect the compositional structure of the actions, and
show how it can be used to diagnose undesired behavior by tracing the
falsification of a specification back to one or more culpable components
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