1,720,959 research outputs found
Proceedings of the 3rd Workshop on Automated Verification of Critical Systems (AVoCS'03)
No full textThe aim of this workshop is to foster a research community in verification in and beyond the United Kingdom of Great Britain through encouraging communication among researchers. Specific objectives include efforts at integration as well as the transfer of methods between different groups from academia and industry. The topics are to be interpreted broadly and inclusively, and in particular cover all aspects of verification (model checking, theorem proving, specification and refinement proofs, etc) pertaining to various types of critical systems, be it safety-critical, business-critical, or performance-critical. The first meeting, AVoCS'01, was held in Oxford (UK), continuing in the tradition of the annual DERA/OUCL series. The second meeting, AVoCS'02, was held in Birmingham (UK). Similarly to previous years, the meeting will be informal, and will combine invited lectures with accepted submissions. This year we also want to aim for wider, European and international attention. Available online at: http://www.ecs.soton.ac.uk/~mal/avocs03
Analysing the Relationship Between Risk and Trust
No full textAmong the various human factors impinging upon making a decision in an uncertain environment, risk and trust are surely crucial ones. Several models for trust have been proposed in the literature but few explicitly take risk into account. This paper analyses the relationship between the two concepts by first looking at how a decision is made based on the risk information. We then draw a model based on a decision surface, and finally derive from it a trust model, called the decision trust, in order to explicitly include risk into the trusting decision
Formal Modelling and Verification of Trust in a Pervasive Application
No full textThis report is deliverable WP4-01 of the project “Trusted Software Agents and Services for Pervasive Information Environments.” The deliverable reports on the activities of formal modelling and verification of a pervasive application which follows from previous results in the project. The pervasive application is based on several pervasive scenarios already devised and is centred on the user location. This location-based system is first architecturally simplified, while trust requirements are derived from the Trust Analysis Framework presented in the deliverable WP2-01. This first abstraction is then completed by formal modelling of the system in the B formal method. These models enable us to clarify the decision decisions leading to fulfil the trust requirements. We show that the system policy structure is influenced by the priorities given to the system operations and that a sufficiently high level of abstraction is required to model trust properties. The modelling activity is completed by formal verification using the ProB model-checker to automate part of this process. Several models are checked successfully, while detection of errors in other models enables us to understand better the behaviour of the system. In particular, issues relative to the dynamicity of modelled elements are highlighted. The overall methodology followed during these activities proved useful at helping us specifying accurately the trust requirements, so that the pervasive application can be completed in consequence, and is as follows: 1) Model important features of the system First vaguely type the variables; then write a set of operations corresponding to complementary features while (possibly) modifying the variable types to ease this writing; consider the variables by group of similar dynamic properties; 2a) Model-check the model 2a.a) Property violation detected Examine the various aspects of the model (variables, enabled operations, history of operations) to see what part of the property is “false”; Correct the model accordingly; 2a.b) No property violation detected Go back to 2a until coverage rate is enough; possible changes to the model include: modify the initialisation to test other situations (in B use “choice by predicate”); add inconsistencies in the model; 2b) Animate the model 2b.a) Execute the desired sequence of operations (validation); 2b.b) Find an interesting state, then 2a.a or 2a.b applies; 2b.c) Backtrack from a state where the invariant is violated; 3) Go back to 1 (complete the model) or refine the model
The Use of Formal Methods in the Analysis of Trust (Position Paper)
No full textSecurity and trust are two properties of modern computing systems that are the focus of much recent interest. They play an increasingly significant role in the requirements for modern computing systems. Security has been studied thoroughly for many years, particularly the sub-domain of cryptography. The use of computing science formal methods has facilitated cryptanalysis of security protocols. At the moment, trust is intensively studied, but not well understood. Here we present our approach based on formal methods for modelling and validating the notion of trust in computing science
Towards a Trust Analysis Framework for Pervasive Computing Scenarios
No full textWe present a scheme for highlighting the trust issues of merit within pervasive computing, based on an analysis of scenarios from the healthcare domain. The first scenario helps us define an analysis grid, where the human and technical aspects of trust are considered. The analysis is applied to a second scenario to examine its suitability. We then discuss the various categories of the analysis grid in the light of this examination and of the literature on the subject of trust. We believe that this approach could form the basis of a generalised trust analysis framework to support the design, procurement and use of pervasive computing
Going Beyond Counting First Authors in Author Co-citation Analysis
Full text linkThe present study examines one of the fundamental aspects of author co-citation analysis (ACA) - the way co-citation
counts are defined. Co-citation counting provides the data on which all subsequent statistical analyses and mappings
are based, and we compare ACA results based on two different types of co-citation counting - the traditional type that
only counts the first one among a cited work's authors on the one hand and a non-traditional type that takes into
account the first 5 authors of a cited work on the other hand. Results indicate that the picture produced through this non-traditional author co-citation counting contains more coherent author groups and is therefore considerably clearer. However, this picture represents fewer specialties in the research field being studied than that produced through the traditional first-author co-citation counting when the same number of top-ranked authors is selected and analyzed. Reasons for these effects are discussed
Variations on the Author
Full text link“Variations on the Author” discusses two of Eduardo Coutinho’s recent films (Um Dia na Vida, from 2010, and Últimas Conversas, posthumously released in 2015) and their contribution to the general question of documentary authorship. The director’s filmography is characterized by a consistent yet self-effacing form of authorial self-inscription: Coutinho often features as an interviewer that rather than express opinions propels discourses; an interviewer that is good at listening. This mode of self-inscription characterizes him as an author who is not expressive but who is nonetheless markedly present on the screen. In Um Dia na Vida, however, Coutinho is completely absent form the image, while Últimas Conversas, on the contrary, includes a confessional prologue that moves the director from the margins to the center of his films. This article examines the ways in which these works stand out in the filmography of a director who offers new insights into the notion of cinematic authorship
Appropriate Similarity Measures for Author Cocitation Analysis
Full text linkWe provide a number of new insights into the methodological discussion about author cocitation analysis. We first argue that the use of the Pearson correlation for measuring the similarity between authors’ cocitation profiles is not very satisfactory. We then discuss what kind of similarity measures may be used as an alternative to the Pearson correlation. We consider three similarity measures in particular. One is the well-known cosine. The other two similarity measures have not been used before in the bibliometric literature. Finally, we show by means of an example that our findings have a high practical relevance.information science;Pearson correlation;cosine;similarity measure;author cocitation analysis
- …
