Can(Plan)+: Extending the Operational Semantics of the BDI Architecture to deal with Uncertain Information

The BDI architecture, where agents are modelled based on their beliefs, desires and intentions, provides a practical approach to develop large scale systems. However, it is not well suited to model complex Supervisory Control And Data Acquisition (SCADA) systems pervaded by uncertainty. In this paper we address this issue by extending the operational semantics of Can(Plan) into Can(Plan)+. We start by modelling the beliefs of an agent as a set of epistemic states where each state, possibly using a different representation, models part of the agent's beliefs. These epistemic states are stratified to make them commensurable and to reason about the uncertain beliefs of the agent. The syntax and semantics of a BDI agent are extended accordingly and we identify fragments with computationally efficient semantics. Finally, we examine how primitive actions are affected by uncertainty and we define an appropriate form of lookahead planning.

Revising Partial Pre-Orders with Partial Pre-Orders: A Unit-Based Revision Framework

Belief revision studies strategies about how agents revise their belief states when receiving new evidence. Both in classical belief revision and in epistemic revision, a new input is either in the form of a (weighted) propositional formula or a total
pre-order (where the total pre-order is considered as a whole).
However, in some real-world applications, a new input can be a partial pre-order where each unit that constitutes the partial pre-order is important and should be considered individually. To address this issue, in this paper, we study how a partial preorder representing the prior epistemic state can be revised by another partial pre-order (the new input) from a different perspective, where the revision is conducted recursively on the individual units of partial pre-orders. We propose different revision operators (rules), dubbed the extension, match, inner and outer revision operators, from different revision points of view. We also analyze several properties for these operators.

Time Efficient Assessment and Feedback Methods for Large Computer-Aided-Design Cohorts

Timely and individualized feedback on coursework is desirable from a student perspective as it facilitates formative development and encourages reflective learning practice. Faculty however are faced with a significant and potentially time consuming challenge when teaching larger cohorts if they are to provide feedback which is timely, individualized and detailed. Additionally, for subjects which assess non-traditional submissions, such as Computer-Aided-Design (CAD), the methods for assessment and feedback tend not to be so well developed or optimized. Issues can also arise over the consistency of the feedback provided. Evaluations of Computer-Assisted feedback in other disciplines (Denton et al, 2008), (Croft et al, 2001) have shown students prefer this method of feedback to traditional “red pen” marking and also that such methods can be more time efficient for faculty.
Herein, approaches are described which make use of technology and additional software tools to speed up, simplify and automate assessment and the provision of feedback for large cohorts of first and second year engineering students studying modules where CAD files are submitted electronically. A range of automated methods are described and compared with more “manual” approaches. Specifically one method uses an application programming interface (API) to interrogate SolidWorks models and extract information into an Excel spreadsheet, which is then used to automatically send feedback emails. Another method describes the use of audio recordings made during model interrogation which reduces the amount of time while increasing the level of detail provided as feedback.
Limitations found with these methods and problems encountered are discussed along with a quantified assessment of time saving efficiencies made.

Massive stars exploding in a He-rich circumstellar medium - V. Observations of the slow-evolving SN Ibn OGLE-2012-SN-006

We present optical observations of the peculiar Type Ibn supernova (SN Ibn) OGLE-2012-SN-006, discovered and monitored by the Optical Gravitational Lensing Experiment-IV survey, and spectroscopically followed by Public ESO Spectroscopic Survey of Transient Objects (PESSTO) at late phases. Stringent pre-discovery limits constrain the explosion epoch with fair precision to JD = 245 6203.8 +/- 4.0. The rise time to the I-band light-curve maximum is about two weeks. The object reaches the peak absolute magnitude M-I = -19.65 +/- 0.19 on JD = 245 6218.1 +/- 1.8. After maximum, the light curve declines for about 25 d with a rate of 4 mag (100 d)(-1). The symmetric I-band peak resembles that of canonical Type Ib/c supernovae (SNe), whereas SNe Ibn usually exhibit asymmetric and narrower early-time light curves. Since 25 d past maximum, the light curve flattens with a decline rate slower than that of the Co-56-Fe-56 decay, although at very late phases it steepens to approach that rate. However, other observables suggest that the match with the Co-56 decay rate is a mere coincidence, and the radioactive decay is not the main mechanism powering the light curve of OGLE-2012-SN-006. An early-time spectrum is dominated by a blue continuum, with only a marginal evidence for the presence of He I lines marking this SN type. This spectrum shows broad absorptions bluewards than 5000 angstrom, likely O II lines, which are similar to spectral features observed in superluminous SNe at early epochs. The object has been spectroscopically monitored by PESSTO from 90 to 180 d after peak, and these spectra show the typical features observed in a number of SN 2006jc-like events, including a blue spectral energy distribution and prominent and narrow (v(FWHM) approximate to 1900 km s(-1)) He I emission lines. This suggests that the ejecta are interacting with He-rich circumstellar material. The detection of broad (10(4) km s(-1)) O I and Ca II features likely produced in the SN ejecta (including the [OI] lambda lambda 6300,6364 doublet in the latest spectra) lends support to the interpretation of OGLE-2012-SN-006 as a core-collapse event.

Probabilistic Planning in AgentSpeak using the POMDP framework.

AgentSpeak is a logic-based programming language, based on the Belief-Desire-Intention (BDI) paradigm, suitable for building complex agent-based systems. To limit the computational complexity, agents in AgentSpeak rely on a plan library to reduce the planning problem to the much simpler problem of plan selection. However, such a plan library is often inadequate when an agent is situated in an uncertain environment. In this paper, we propose the AgentSpeak+ framework, which extends AgentSpeak with a mechanism for probabilistic planning. The beliefs of an AgentSpeak+ agent are represented using epistemic states to allow an agent to reason about its uncertain observations and the uncertain effects of its actions. Each epistemic state consists of a POMDP, used to encode the agent’s knowledge of the environment, and its associated probability distribution (or belief state). In addition, the POMDP is used to select the optimal actions for achieving a given goal, even when facing uncertainty.

Violence and Commemoration in the New Northern Ireland: Space, Memory and Management

On June 27th 2012, the Deputy First Minister of Northern Ireland and former IRA commander, Martin McGuinness shook hands with Queen Elizabeth II for the first time at an event in Belfast. For many the gesture symbolised the consolidation of Northern Ireland's transition to peace, the meeting of cultures and traditions, and hope for the future. Only a few weeks later however violence spilled onto the streets of north and west Belfast following a series of commemorative parades, marking a summer of hostilities. Those hostilities spread into a winter of protest, riot and discontent around flags and emblems and a year of tensions and commemorative-related violence marked again by a summer of rioting and protest in 2013. Outwardly these examples present two very different pictures of the 'new' Northern Ireland; the former of a society moving forward and putting the past behind it and the latter apparently divided over and wedded to different constructions of the past. Furthermore they revealed two very different 'places', the public handshake in the arena of public space; the rioting and fighting occurring in spaces distanced from the public sphere. This paper has also illustrated the difficulties around the ‘public management’ of conflict and transition as many within public agencies struggle with duties to uphold good relations and promote good governance within an environment of political strife, hostility and continuing violence.

This paper presents the key findings and implications of an exploratory project funded by the Arts and Humanities Research Council, explored the phenomenon of commemorative-related violence in Northern Ireland. We focus on 1) why the performance or celebration of the past can sometimes lead to violence in specific places; 2) map and analyse the levels of commemorative related violence in the past 15 years and 3) look at the public management implications of both conflict and transition at a strategic level within the public sector.

Semantics for possibilistic answer set programs: uncertain rules versus rules with uncertain conclusions

Although Answer Set Programming (ASP) is a powerful framework for declarative problem solving, it cannot in an intuitive way handle situations in which some rules are uncertain, or in which it is more important to satisfy some constraints than others. Possibilistic ASP (PASP) is a natural extension of ASP in which certainty weights are associated with each rule. In this paper we contrast two different views on interpreting the weights attached to rules. Under the first view, weights reflect the certainty with which we can conclude the head of a rule when its body is satisfied. Under the second view, weights reflect the certainty that a given rule restricts the considered epistemic states of an agent in a valid way, i.e. it is the certainty that the rule itself is correct. The first view gives rise to a set of weighted answer sets, whereas the second view gives rise to a weighted set of classical answer sets.

Weak and strong disjunction in possibilistic ASP

Possibilistic answer set programming (PASP) unites answer set programming (ASP) and possibilistic logic (PL) by associating certainty values with rules. The resulting framework allows to combine both non-monotonic reasoning and reasoning under uncertainty in a single framework. While PASP has been well-studied for possibilistic definite and possibilistic normal programs, we argue that the current semantics of possibilistic disjunctive programs are not entirely satisfactory. The problem is twofold. First, the treatment of negation-as-failure in existing approaches follows an all-or-nothing scheme that is hard to match with the graded notion of proof underlying PASP. Second, we advocate that the notion of disjunction can be interpreted in several ways. In particular, in addition to the view of ordinary ASP where disjunctions are used to induce a non-deterministic choice, the possibilistic setting naturally leads to a more epistemic view of disjunction. In this paper, we propose a semantics for possibilistic disjunctive programs, discussing both views on disjunction. Extending our earlier work, we interpret such programs as sets of constraints on possibility distributions, whose least specific solutions correspond to answer sets.

Establishing the ‘Truth’ of the Matter: Confessional Reflexivity as Introspection and Avowal

The conceptualisation of reflexivity commonly found in social anthropology deploys the term as if it were both a ‘virtuous’ mechanism of self‐reflection and an ethical technique of truth telling, with reflexivity frequently deployed as an moral practice of introspection and avowal. Further, because reflexivity is used as a methodology for constructing the authority of ethnographic accounts, reflexivity in anthropology has come to closely resemble Foucault’s descriptions of confession. By discussing Lynch’s (2000) critical analysis of reflexivity as an ‘academic virtue’, I consider his argument through the lens of my own concept of ‘confessional reflexivity’. While supporting Lynch’s diagnosis of the ‘problem of reflexivity’, I attempt to critique his ethnomethodological cure as essentialist, I conclude that a way forward might be found by blending Foucault’s (1976, 1993) theory of confession with Bourdieu’s (1992) theory of ‘epistemic reflexivity’.

The Changing Context for Planning Education in the UK and the Prospects for Research-Led, Practice-Engaged Teaching

The UK’s Royal Town Planning Institute (RTPI) has celebrated its centenary in 2014, marking 100 years of close relationships between university-based planning schools and a professional body focused on planning practice. During this period, the context for university education and the very idea of planning have changed dramatically contributing to a continual renegotiation of the relationships between the planning profession and the educational institutions it accredits. These changes have been particularly pronounced in the last 10 years where a number of factors have forced a rapid change in the nature of planjavascript:void(0);ning education in the UK. This has included a boom and then slump in the number of planning students linked to the dynamics of national economic situation, a reorganization of many planning school curricula, and their merger with cognate disciplines such as geography and an increased focus on research output, rather than professional engagement as the key indicator of institutional success. This last factor adds a particularly new dimension to the profession-university relationship, which could potentially lead to either straining of tensions or a synergy through research-led teaching that could significantly benefit both. This chapter will briefly review the evolution of UK planning schools and of the main ideas informing planning education. It will then describe the current profile of UK planning schools, based on an extensive national survey conducted on behalf of the Royal Town Planning Institute. The paper will then critically review the main challenges and opportunities facing UK planning schools in the context of changes in both planning practice and higher education. It will then move on to the concept of research-led teaching, drawing on current practice in the UK and review how well this concept serves students and the idea of developing reflective planning practitioners. Finally, the paper will seek to draw broad lessons from the experience of the UK and reflect on the type of planning education that can best serve planning professions in a variety of international contexts in the future.