Julian Padget

Formalizing a Language for Institutions and Norms

One source of trust for physical trading systems is their physical assets and simply their presence. A similar baseline does not exist for electronic trading systems, but one way in which it may be possible to create that initial trust is through the abstract notion of an institution, defined in terms of norms [19] and the scenes within which (software) agents may play roles in different trading activities, governed by those norms. We present here a case for institutions in electronic trading, a specification language for institutions (covering norms, performative structure, scenes, roles, etc.) and its semantics and how this may be mapped into formal languages such as process algebra and various forms of logic, so that there is a framework within which norms can be stated and proven.

Coordination, Organizations, Institutions, and Norms in Agent Systems III

This book constitutes the thoroughly refereed proceedings of the 9th International Workshops on Coordination, Organizations, Institutions and Norms in Agent Systems, COIN 2013. The workshops were co-located with AAMAS 2013, held in St. Paul, MN, USA in May 2013, and with PRIMA 2013, held in Dunedin, New Zealand, in December 2013. The 18 full papers were carefully reviewed and selected from 28 submissions and are presented together with two invited papers. The papers are organized in topical sections such as coordination, organizations, institutions, norms, norm conflict, and norm-aware agents.

Coordination, Organizations, Institutions, and Norms in Multi-Agent Systems

This book constitutes the thoroughly refereed post-proceedings of the International Workshop on Agents, Norms and Institutions for Regulated Multiagent Systems, ANIREM 2005, and the International Workshop on Organizations in Multi-Agent Systems, OOOP 2005, held in Utrecht, The Netherlands in July 2005 as an associated event of AAMAS 2005. This volume is the first in a series focussing on issues in Coordination, Organizations, Institutions and Norms (COIN) in multi-agent systems. The 17 papers in this volume are extended, revised versions of the best papers presented at the ANIREM and the OOOP workshops at AAMAS 2005 that were carefully selected during two rounds of reviewing and improvement. The papers from the two workshops have been re-grouped around the following themes: modelling, analyzing and programming organizations, modelling and analyzing institutions, modelling normative designs, as well as evaluation and regulation.

Answer set programming for representing and reasoning about virtual institutions

It is recognised that institutions are potentially powerful means for making agent interactions effective and efficient, but institutions will only really be useful when, as in other safety-critical scenarios, it is possible to prove that particular properties do or do not hold for all possible encounters. In contrast to symbolic model-checking, answer set programming permits the statement of problems and queries in domain-specific terms as executable logic programs, thus eliminating the gap between specification and verification language. Furthermore, results are presented in the same terms. In this paper we describe the use of answer set programs as an institutional modelling technique. We demonstrate that our institutional model can be intuitively be mapped into an answer set program such that the ordered event traces of the former can be obtained as the answer sets of the latter, allowing for an easy way to query properties of models.

Using software agents to preserve individual health data confidentiality in micro-scale geographical analyses

Confidentiality constraints often preclude the release of disaggregate data about individuals, which limits the types and accuracy of the results of geographical health analyses that could be done. Access to individually geocoded (disaggregate) data often involves lengthy and cumbersome procedures through review boards and committees for approval (and sometimes is not possible). Moreover, current data confidentiality-preserving solutions compatible with fine-level spatial analyses either lack flexibility or yield less than optimal results (because of confidentiality-preserving changes they introduce to disaggregate data), or both. In this paper, we present a simulation case study to illustrate how some analyses cannot be (or will suffer if) done on aggregate data. We then quickly review some existing data confidentiality-preserving techniques, and move on to explore a solution based on software agents with the potential of providing flexible, controlled (software-only) access to unmodified confidential disaggregate data and returning only results that do not expose any person-identifiable details. The solution is thus appropriate for micro-scale geographical analyses where no person-identifiable details are required in the final results (i.e., only aggregate results are needed). Our proposed software agent technique also enables post-coordinated analyses to be designed and carried out on the confidential database(s), as needed, compared to a more conventional solution based on the Web Services model that would only support a rigid, pre-coordinated (pre-determined) and rather limited set of analyses. The paper also provides an exploratory discussion of mobility, security, and trust issues associated with software agents, as well as possible directions/solutions to address these issues, including the use of virtual organizations. Successful partnerships between stakeholder organizations, proper collaboration agreements, clear policies, and unambiguous interpretations of laws and regulations are also much needed to support and ensure the success of any technological solution.

Symbolic model checking of UML statechart diagrams with an integrated approach

This paper puts forward a new approach for the specification and verification of finite state systems. The design of a system is first specified in UML statechart diagrams, then formalized in the /spl pi/calculus and finally verified automatically by NuSMV. We demonstrate an application of the proposed approach using the SET/A protocol as an example.

Specifying and analysing agent-based social institutions using answer set programming

In this paper we discuss the use of the Answer Set Programming paradigm for representing and analysing specifications of agent-based institutions. We outline the features of institutions we model, and describe how they are translated into ASP programs which can then be used to verify properties of the specifications. We demonstrate the effectiveness of this approach through the institutions of property and exchange.

Virtual visual sensors and their application in structural health monitoring

Wireless sensor networks are being increasingly accepted as an effective tool for structural health monitoring. The ability to deploy a wireless array of sensors efficiently and effectively is a key factor in structural health monitoring. Sensor installation and management can be difficult in practice for a variety of reasons: a hostile environment, high labour costs and bandwidth limitations. We present and evaluate a proof-of-concept application of virtual visual sensors to the well-known engineering problem of the cantilever beam, as a convenient physical sensor substitute for certain problems and environments. We demonstrate the effectiveness of virtual visual sensors as a means to achieve non-destructive evaluation. Major benefits of virtual visual sensors are its non-invasive nature, ease of installation and cost-effectiveness. The novelty of virtual visual sensors lies in the combination of marker extraction with visual tracking realised by modern computer vision algorithms. We demonstrate that by deploying a collection of virtual visual sensors on an oscillating structure, its modal shapes and frequencies can be readily extracted from a sequence of video images. Subsequently, we perform damage detection and localisation by means of a wavelet-based analysis. The contributions of this article are as follows: (1) use of a sub-pixel accuracy marker extraction algorithm to construct virtual sensors in the spatial domain, (2) embedding dynamic marker linking within a tracking-by-correspondence paradigm that offers benefits in computational efficiency and registration accuracy over traditional tracking-by-searching systems and (3) validation of virtual visual sensors in the context of a structural health monitoring application.

Energy efficient zone based routing protocol for MANETs

Mobile Ad Hoc Networks (MANET) are self-configuring infrastructureless networks of mobile devices connected via wireless links. Each device can send and receive data, but it should also forward traffic unrelated to its own use. All need to maintain their autonomy, and effectively preserve their resources (e.g. battery power). Moreover, they can leave the network at any time. Their intrinsic dynamicity and fault tolerance makes them suitable for applications, such as emergency response and disaster relief, when infrastructure is nonexistent or damaged due to natural disasters, such as earthquakes and flooding, as well as more mundane, day-to-day, uses where their flexibility would be advantageous.Routing is the fundamental research issue for such networks and refers to finding and maintaining routes between nodes. Moreover, it involves selecting the best route where many may be available. However, due to the freedom of movement of nodes, new routes need to be constantly recalculated. Most routing protocols use pure broadcasting to discover new routes, which takes up a substantial amount of bandwidth. Intelligent rebroadcasting reduces these overheads by calculating the usefulness of a rebroadcast, and the likelihood of message collisions. Unfortunately, this introduces latency and parts of the network may become unreachable. This paper discusses the Zone based Routing with Parallel Collision Guided Broadcasting Protocol (ZCG) that uses parallel and distributed broadcasting technique (Basurra et al., 2010) 8 to reduce redundant broadcasting and to accelerate the path discovery process, while maintaining a high reachability ratio as well as keeping node energy consumption low.ZCG uses a one hop clustering algorithm that splits the network into zones led by reliable leaders that are mostly static and have plentiful battery resources. The performance characteristics of the ZCG protocol are established through simulations by comparing it to other well-known routing protocols, namely the: AODV and DSR. It emerges that ZCG performs well under many circumstances.

Matchmaking Framework for Mathematical Web Services

Service discovery and matchmaking in a distributed environment has been an active research issue for some time now. Previous work on matchmaking has typically presented the problem and service descriptions as free or structured (marked-up) text, so that keyword searches, tree-matching or simple constraint solving are sufficient to identify matches. In this paper, we discuss the problem of matchmaking for mathematical services, where the semantics play a critical role in determining the applicability or otherwise of a service and for which we use OpenMath descriptions of pre- and post-conditions. We describe a matchmaking architecture supporting the use of match plug-ins and describe five kinds of plug-in that we have developed to date: (i) A basic structural match, (ii) a syntax and ontology match, (iii) a value substitution match, (iv) an algebraic equivalence match and (v) a decomposition match. The matchmaker uses the individual match scores from the plug-ins to compute a ranking by applicability of the services. We consider the effect of pre- and post-conditions of mathematical service descriptions on matching, and how and why to reduce queries into Disjunctive Normal Form (DNF) before matching. A case study demonstrates in detail how the matching process works for all four algorithms.