31,560 research outputs found
Applying Formal Methods to Networking: Theory, Techniques and Applications
Despite its great importance, modern network infrastructure is remarkable for
the lack of rigor in its engineering. The Internet which began as a research
experiment was never designed to handle the users and applications it hosts
today. The lack of formalization of the Internet architecture meant limited
abstractions and modularity, especially for the control and management planes,
thus requiring for every new need a new protocol built from scratch. This led
to an unwieldy ossified Internet architecture resistant to any attempts at
formal verification, and an Internet culture where expediency and pragmatism
are favored over formal correctness. Fortunately, recent work in the space of
clean slate Internet design---especially, the software defined networking (SDN)
paradigm---offers the Internet community another chance to develop the right
kind of architecture and abstractions. This has also led to a great resurgence
in interest of applying formal methods to specification, verification, and
synthesis of networking protocols and applications. In this paper, we present a
self-contained tutorial of the formidable amount of work that has been done in
formal methods, and present a survey of its applications to networking.Comment: 30 pages, submitted to IEEE Communications Surveys and Tutorial
Automated Game Design Learning
While general game playing is an active field of research, the learning of
game design has tended to be either a secondary goal of such research or it has
been solely the domain of humans. We propose a field of research, Automated
Game Design Learning (AGDL), with the direct purpose of learning game designs
directly through interaction with games in the mode that most people experience
games: via play. We detail existing work that touches the edges of this field,
describe current successful projects in AGDL and the theoretical foundations
that enable them, point to promising applications enabled by AGDL, and discuss
next steps for this exciting area of study. The key moves of AGDL are to use
game programs as the ultimate source of truth about their own design, and to
make these design properties available to other systems and avenues of inquiry.Comment: 8 pages, 2 figures. Accepted for CIG 201
Leveraging Semantic Web Service Descriptions for Validation by Automated Functional Testing
Recent years have seen the utilisation of Semantic Web Service descriptions for automating a wide range of service-related activities, with a primary focus on service discovery, composition, execution and mediation. An important area which so far has received less attention is service validation, whereby advertised services are proven to conform to required behavioural specifications. This paper proposes a method for validation of service-oriented systems through automated functional testing. The method leverages ontology-based and rule-based descriptions of service inputs, outputs, preconditions and effects (IOPE) for constructing a stateful EFSM specification. The specification is subsequently utilised for functional testing and validation using the proven Stream X-machine (SXM) testing methodology. Complete functional test sets are generated automatically at an abstract level and are then applied to concrete Web services, using test drivers created from the Web service descriptions. The testing method comes with completeness guarantees and provides a strong method for validating the behaviour of Web services
Blazes: Coordination Analysis for Distributed Programs
Distributed consistency is perhaps the most discussed topic in distributed
systems today. Coordination protocols can ensure consistency, but in practice
they cause undesirable performance unless used judiciously. Scalable
distributed architectures avoid coordination whenever possible, but
under-coordinated systems can exhibit behavioral anomalies under fault, which
are often extremely difficult to debug. This raises significant challenges for
distributed system architects and developers. In this paper we present Blazes,
a cross-platform program analysis framework that (a) identifies program
locations that require coordination to ensure consistent executions, and (b)
automatically synthesizes application-specific coordination code that can
significantly outperform general-purpose techniques. We present two case
studies, one using annotated programs in the Twitter Storm system, and another
using the Bloom declarative language.Comment: Updated to include additional materials from the original technical
report: derivation rules, output stream label
A Product Oriented Modelling Concept: Holons for systems synchronisation and interoperability
Nowadays, enterprises are confronted to growing needs for traceability,
product genealogy and product life cycle management. To meet those needs, the
enterprise and applications in the enterprise environment have to manage flows
of information that relate to flows of material and that are managed in shop
floor level. Nevertheless, throughout product lifecycle coordination needs to
be established between reality in the physical world (physical view) and the
virtual world handled by manufacturing information systems (informational
view). This paper presents the "Holon" modelling concept as a means for the
synchronisation of both physical view and informational views. Afterwards, we
show how the concept of holon can play a major role in ensuring
interoperability in the enterprise context
Extracting Ontologies From Neural Networks
Artificial neural network-based methods have been growing in popularity, being success-
fully applied to perform a variety of tasks. As these systems begin to be deployed in
domains where it is desired that they have a certain degree of autonomy and respon-
sibility, the need to comprehend the reasoning behind their answers is becoming a re-
quirement. Though, neural networks are still regarded as black boxes, since their internal
representation do not provide any human-understandable explanation for their outputs.
A considerable amount of work has been done towards the development of methods to
increase the interpretability of neural networks. However, these methods often produce
interpretations are too complex and do not have any declarative meaning, leaving the
user with the burden of rationalizing them. Recent work has shown that it is possible
to establish mappings between a neural network’s internal representations and a set of
human-understandable concepts. In this dissertation we propose a method that leverage
these mappings to induce an ontology that describes a neural network’s classification
process, through logical relations between human-understandable concepts.Métodos com base em redes neuronais artificiais têm ganho cada vez mais popularidade,
e têm sido aplicados na resolução das mais variadas tarefas. À medida que estes sistemas
são usados em domÃnios onde se pretende que tenham um determinado grau de auto-
nomia e responsabilidade, a necessidade de compreender o raciocÃnio que os conduz à s
suas respostas torna-se indispensável. No entanto, as redes neuronais são vistas como
caixas negras, dado que as suas representações internas não constituem uma explicação
interpretável para os seus resultados. Tem sido realizada uma quantidade considerável
de investigação com o objetivo de desenvolver métodos que permitam o aumento da
interpretabilidade de redes neuronais. Todavia, estes métodos tendem a produzir inter-
pretações complexas e a que não possuem nenhum significado declarativo, deixando o
utilizador com a responsabilidade as racionalizar. Uma publicação recente mostrou que é
possÃvel estabelecer mapeamentos entre as representações internas de uma rede neuronal
e conceitos interpretáveis. Nesta dissertação propomos um método que faz uso destes
mapeamentos para induzir uma ontologia que reflete o processo de classificação de uma
rede neuronal, através de conceitos compreensiveis relacionados logicamente
Grounding semantics in robots for Visual Question Answering
In this thesis I describe an operational implementation of an object detection and description system that incorporates in an end-to-end Visual Question Answering system and evaluated it on two visual question answering datasets for compositional language and elementary visual reasoning
Induction, complexity, and economic methodology
This paper focuses on induction, because the supposed weaknesses of that process are the main reason for favouring falsificationism, which plays an important part in scientific methodology generally; the paper is part of a wider study of economic methodology. The standard objections to, and paradoxes of, induction are reviewed, and this leads to the conclusion that the supposed ‘problem’ or ‘riddle’ of induction is a false one. It is an artefact of two assumptions: that the classic two-valued logic (CL) is appropriate for the contexts in which induction is relevant; and that it is the touchstone of rational thought. The status accorded to CL is the result of historical and cultural factors. The material we need to reason about falls into four distinct domains; these are explored in turn, while progressively relaxing the restrictions that are essential to the valid application of CL. The restrictions include the requirement for a pre-existing, independently-guaranteed classification, into which we can fit all new cases with certainty; and non-ambiguous relationships between antecedents and consequents. Natural kinds, determined by the existence of complex entities whose characteristics cannot be unbundled and altered in a piecemeal, arbitrary fashion, play an important part in the review; so also does fuzzy logic (FL). These are used to resolve two famous paradoxes about induction (the grue and raven paradoxes); and the case for believing that conventional logic is a subset of fuzzy logic is outlined. The latter disposes of all questions of justifying induction deductively. The concept of problem structure is used as the basis for a structured concept of rationality that is appropriate to all four of the domains mentioned above. The rehabilitation of induction supports an alternative definition of science: that it is the business of developing networks of contrastive, constitutive explanations of reproducible, inter-subjective (‘objective’) data. Social and psychological obstacles ensure the progress of science is slow and convoluted; however, the relativist arguments against such a project are rejected.induction; economics; methodology; complexity
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