Abstraction in situation calculus action theories

We develop a general framework for agent abstraction based on the situation calculus and the ConGolog agent programming language. We assume that we have a high-level specification and a low-level specification of the agent, both repre- sented as basic action theories. A refinement mapping specifies how each high-level action is implemented by a low- level ConGolog program and how each high-level fluent can be translated into a low-level formula. We define a notion of sound abstraction between such action theories in terms of the existence of a suitable bisimulation between their respective models. Sound abstractions have many useful properties that ensure that we can reason about the agent’s actions (e.g., executability, projection, and planning) at the abstract level, and refine and concretely execute them at the low level. We also characterize the notion of complete abstraction where all actions (including exogenous ones) that the high level thinks can happen can in fact occur at the low level

Abstraction in situation calculus action theories

We develop a general framework for agent abstraction based on the situation calculus and the ConGolog agent programming language. We assume that we have a high-level specification and a low-level specification of the agent, both repre- sented as basic action theories. A refinement mapping specifies how each high-level action is implemented by a low- level ConGolog program and how each high-level fluent can be translated into a low-level formula. We define a notion of sound abstraction between such action theories in terms of the existence of a suitable bisimulation between their respective models. Sound abstractions have many useful properties that ensure that we can reason about the agent’s actions (e.g., executability, projection, and planning) at the abstract level, and refine and concretely execute them at the low level. We also characterize the notion of complete abstraction where all actions (including exogenous ones) that the high level thinks can happen can in fact occur at the low level

Bounded Situation Calculus Action Theories

In this paper, we investigate bounded action theories in the situation calculus. A bounded action theory is one which entails that, in every situation, the number of object tuples in the extension of fluents is bounded by a given constant, although such extensions are in general different across the infinitely many situations. We argue that such theories are common in applications, either because facts do not persist indefinitely or because the agent eventually forgets some facts, as new ones are learnt. We discuss various classes of bounded action theories. Then we show that verification of a powerful first-order variant of the mu-calculus is decidable for such theories. Notably, this variant supports a controlled form of quantification across situations. We also show that through verification, we can actually check whether an arbitrary action theory maintains boundedness.Comment: 51 page

ElGolog: A High-Level Programming Language with Memory of the Execution History

Most programming languages only support tests that refer exclusively to the current state. This applies even to high-level programming languages based on the situation calculus such as Golog. The result is that additional variables/fluents/data structures must be introduced to track conditions that the pro- gram uses in tests to make decisions. In this paper, drawing inspiration from McCarthy’s Elephant 2000, we propose an extended version of Golog, called ElGolog, that supports rich tests about the execution history, where tests are expressed in a first-order variant of two-way linear dynamic logic that uses ElGolog programs with converse. We show that in spite of rich tests, ElGolog shares key features with Golog, including a sematics based on macroexpansion into situation calculus formulas, upon which regression can still be applied. We also show that like Golog, our extended language can easily be implemented in Prolog

LTL Verification of Online Executions with Sensing in Bounded Situation Calculus

Abstract. We look at agents reasoning about actions from a firstperson perspective. The agent has a representation of world as situation calculus action theory. It can perform sensing actions to acquire information. The agent acts “online”, i.e., it performs an action only if it is certain that the action can be executed, and collects sensing results from the actual world. When the agent reasons about its future actions, it indeed considers that it is acting online; however only possible sensing values are available. The kind of reasoning about actions we consider for the agent is verifying a first-order (FO) variant (without quantification across situations) of linear time temporal logic (LTL). We mainly focus on bounded action theories, where the number of facts that are true in any situation is bounded. The main results of this paper are: (i) possible sensing values can be based on consistency if the initial situation description is FO; (ii) for bounded action theories, progression over histories that include sensing results is always FO; (iii) for bounded theories, verifying our FO LTL against online executions with sensing is decidable.

« Aille.Aille Aille. Y’a du pain sur la planche » : expériences et perspectives étudiantes sur les liens entre le travail social et l’environnement dans la formation en travail social au Québec

Dans les dernières années, différents enjeux environnementaux ont occupé un espace médiatique important, de désastres variés à joutes politiques autour d’enjeux de développement des énergies fossiles. Or, bien que les liens entre environnement et inégalités sociales fassent de plus en plus partie des discours, les écrits empiriques en travail social en français demeurent rares sur les liens entre l’environnement et le travail social. Dans de nombreux articles, la formation en travail social est identifiée comme un point de départ nécessaire pour entamer une réflexion à ce sujet. Il constituera donc, pour nous, le terrain choisi pour cette recherche exploratoire. Plus précisément, ce projet de mémoire s’intéressera donc à mieux comprendre les expériences et réflexions étudiantes sur les liens entre l’environnement et le travail social, s’intéressant à les documenter à partir de leur parcours de formation. Les données qualitatives ont été recueillies par le biais de trois groupes de discussion en ligne, regroupant des personnes qui étudient en travail social dans des universités québécoises. Une analyse thématique réflexive, ancrée dans une méthodologie féministe et guidée par un cadre théorique féministe et un cadre conceptuel nepantla, aura permis de dégager les constats principaux de ce mémoire. Une démarche réflexive a aussi accompagné ce processus de mémoire, et a été utilisée pour trianguler les données. Sept thèmes se dégagent ainsi des données, décrivant les expériences et réflexions étudiantes témoignées : (1) « De nature à crise du logement : une définition de l’environnement en discussion », (2) Comment intervenir ? Des idées variées (3) « Dans les marges des cours : des liens peu abordés » (4) « Entre privé et public : partager son vécu émotif » (5) « Entre individu et société : Questionner la formation ». (6) « Entre enseignement et apprentissage : s’outiller entre paires ». et (7) « Entre préventions et urgence : réfléchir la responsabilité professionnelle ». Ces thèmes permettent de mieux comprendre les préoccupations étudiantes, et peuvent servir de tremplin pour guider des transformations dans la formation en travail social au Québec.In recent years, various environmental issues have occupied a significant amount of media space, from various disasters caused by human activity to political games around the development of fossil fuels. However, although connections between environmental and social inequalities are increasingly part of the public discourse, empirical writings on the links between the environment and social work in French are still rare. In articles from various provinces and countries, social work education is identified as a necessary starting point for reflection on this topic. It will therefore be the chosen field for this exploratory research. More specifically, this master’s thesis will aim to better understand students’ experiences and reflections on the links between the environment and social work, documenting it from their educational pathway. Qualitative data was collected through three online focus groups of social work students enrolled in Quebec universities. A reflexive thematic analysis, anchored in a feminist theoretical framework and methodology and informed by a nepantla conceptual framework, guided the process for this thesis. A reflexive approach also accompanied this thesis and was used to triangulate and question the research data. Seven themes emerged from the focus groups, describing the students’ experiences and reflections: (1) “From nature to housing crisis: a definition of environment under discussion,” (2) How to intervene? Various ideas, (3) “In the margins of courses: absent links”, (4) “Between private and public: sharing one’s emotional experience”, (5) “Between individual and society: questioning training”. (6) “Between teaching and learning: equipping oneself among peers” and (7) “Between prevention and emergency: reflecting on professional responsibility”. These themes not only allow for a better understanding of student concerns but can also serve as an interesting springboard to guide transformations in social work education in Quebec

La compétence internationale des tribunaux dans les poursuites civiles contre les sociétés transnationales pour violation des droits humains : une critique de la jurisprudence québécoise

Aucune instance spécifique n’existe sur le plan international pour les litiges civils impliquant la violation par les sociétés transnationales (ci après, STN) des normes de droits humains. Les tribunaux nationaux représentent l’instance compétente afin d’entendre ces causes de droit international privé. Cependant, les tribunaux originaires des STN manifestent leur réticence à exercer leur compétence, alors que les États où sont commises les violations souffrent parfois d’un important déficit de gouvernance. Les victimes se retrouvent ainsi fréquemment sans forum adéquat où adresser leur requête pour les dommages subis. L’objectif du mémoire est de rechercher puis d’élaborer différents arguments afin de faire évoluer l’interprétation de la compétence des tribunaux québécois actuellement préconisée dans le cadre de deux jurisprudences phares en matière d’activité des STN à l’étranger, soit Association canadienne contre l’impunité (ACCI) c. Anvil Mining Ltd., et Recherches Internationales Québec c. Cambior Inc. Le premier chapitre porte sur les règles fondant la compétence des autorités québécoises et les principes les sous-tendant. Notre deuxième chapitre se consacrera à la recherche d’arguments au sein de la jurisprudence étrangère. Notre troisième chapitre présentera les arguments de nature politique, sociale, éthique et théorique rencontrés dans le domaine du droit global. Nous verrons alors plusieurs propositions théoriques afin de mieux appréhender les problèmes liés au vide juridictionnel dont souffrent les victimes demanderesses. Cet éclairage théorique contribuera à justifier l’apport du droit international privé dans le contrôle du respect par les STN des normes de droits humains.Internationally, there is no specific forum to institute civil proceedings involving the violation of human rights by a transnational corporation (hereafter, « TNC »). Therefore, national courts remain the appropriate legal venue for hearing private international legal causes. However, home state courts are reluctant to recognize and exercise their competence in this type of litigation, whereas host state forum often lack effective governance. Victims are therefore often left with no adequate forum where their request for damages can be addressed. The purpose of this thesis is to research and elaborate different arguments that may change the currently preferred interpretation concerning the competence of Québec courts based on two landmark rulings on the activity of TCNs in foreign countries: Canadian Association Against Impunity (CAAI) v. Anvil Mining Ltd., and Recherches Internationales Québec v. Cambior Inc. In the first chapter, the rules that form the basis of the competence of the Québec authorities will be described, as well as the principles underpinning them. The second chapter is devoted to a search for arguments within the body of foreign case law. The third chapter presents the theoretical arguments found in the field of global law. Several theoretical propositions will be examined in order to further explore the problems associated with the lack of jurisdiction affecting the victims of human rights violations by TNCs. This theoretical contribution will also serve to justify the role of private international law in obliging TNCs to respect human rights standards

Analyse acoustique de la conviction exprimée dans des réponses de sondage : un raffinement des enquêtes téléphoniques

Les sondages téléphoniques visent habituellement l’enregistrement de réponses selon leur contenu linguistique littéral (« oui », « jamais », nom de politiciens, etc.). Cependant, les réponses orales contiennent également des aspects acoustiques qui expriment le degré de conviction des répondants. Dans les techniques actuelles de sondage, cette information, dite « extralinguistique », n’est pas retenue bien qu’elle puisse servir à la prédiction des comportements des répondants. Le présent mémoire a pour objectif de démontrer que des mesures acoustiques de la conviction exprimée par les répondants peuvent servir à améliorer la prédiction de comportements telle qu’estimée par les techniques de sondage. Cette démonstration se fait en deux étapes et implique deux expériences. L’Expérience 1, réalisée en laboratoire (n = 25), avait pour but d’isoler les variables vocales associées à l’expression de la conviction. Ce test a permis d’isoler des variables mesurables pertinentes et les distributions catégoriques de valeurs permettant une catégorisation des réponses selon un « degré de conviction ». L’Expérience 2 a porté sur l’application de ces mesures acoustiques dans l’analyse de réponses enregistrées lors d’un sondage téléphonique préélectoral fait par la firme Léger en 2010 (un corpus de 400 entrevues). Cette deuxième expérience a démontré qu’une catégorisation des réponses nominatives (n = 188) sur la base des variables associées à l’expression de la conviction (telles que définies à l’Expérience 1) peut améliorer la prédiction des comportements des électeurs. Les résultats suggèrent que les réponses orales à un sondage contiennent des indices acoustiques mesurables qui expriment un degré de conviction relié à une volonté de produire certains comportements. La nature de ces variables présente aussi la possibilité d’une détection automatique.Surveys by phone usually involve the recording of responses in terms of their literal linguistic content ("yes", "never", politician name, etc.). However, oral responses also possess acoustic aspects that express a degree of conviction of respondents. In current survey techniques, this "extralinguistic" information is not considered although it can be used to predict the respondent’s behavior. This paper aims to demonstrate that acoustic measures of the conviction expressed by respondents can be used to improve the prediction of behaviors as estimated by survey techniques. This demonstration is done in two steps involving two experiments. Experiment 1, conducted in a laboratory setting (n = 25), was designed to isolate the vocal variables associated with the expression of the conviction. This first test served to isolate the relevant measurable variables and "categorical" values that could be used to categorize oral responses. Experiment 2 involved the application of these acoustic measures in the analysis of responses recorded during a pre-election telephone survey conducted by Leger in 2010 (a corpus of 400 interviews). This second experiment showed that a categorization of oral responses (n = 188) based on the basis of values of expressed conviction (as defined in Experiment 1) can improve the prediction of the behavior of voters. The results suggest that oral-survey responses contain measurable acoustic cues that express a degree of conviction, which can be associated with a willingness to produce certain behaviors. The nature of the variables also presents the possibility of an automatic detection. The nature of the variables also presents the possibility of an automatic detection