Reasoning techniques for analysis and refinement of policies for service management

The work described in this technical report falls under the general problem of developing methods that would allow us to engineer software systems that are reliable and would offer a certain acceptable level of quality in their operation. This report shows how the analysis and refinement of policies for Quality of Service can be carried out within logic by exploiting forms of abductive and argumentative reasoning. In particular, it provides two main contributions. The first is an extension of earlier work on the use of abductive reasoning for automatic policy refinement by exploiting the use of integrity constraints within abduction and its integration with constraint solving. This has allowed us to enhance this refinement process in various ways, e.g. supporting parameter values derivation to quantify abstract refinement to specific policies ready to be put in operation, and calculating utility values to determine optimal refined policies. The second contribution is a new approach for modelling and formulating Quality of Service policies, and more general policies for software requirements, as preference policies within logical frameworks of argumentation. This is shown to be a flexible and declarative approach to the analysis of such policies through high-level semantic queries of argumentation, demonstrated here for the particular case of network firewall policies where the logical framework of argumentation allows us to detect anomalies in the firewalls and facilitates the process of their resolution. To our knowledge this is the first time that the link between argumentation and the specification and analysis of requirement policies has been studied

A goal-based approach to policy refinement

As the interest in using policy-based approaches for systems management grows, it is becoming increasingly important to develop methods for performing analysis and refinement of policy specifications. Although this is an area that researchers have devoted some attention to, none of the proposed solutions address the issue of deriving implementable policies from high-level goals. A key part of the solution to this problem is having the ability to identify the operations, available on the underlying system, which can achieve a given goal. This paper presents an approach by which a formal representation of a system, based on the Event Calculus, can be used in conjunction with abductive reasoning techniques to derive the sequence of operations that will allow a given system to achieve a desired goal. Additionally it outlines how this technique might be used for providing tool support and partial automation for policy refinement. Building on previous work on using formal techniques for policy analysis, the approach presented here applies a transformation of both policy and system behaviour specifications into a formal notation that is based on Event Calculus. Finally, it shows how the overall process could be used in conjunction with UML modelling and illustrates this by means of an example. 1

Interactive Knowledge Construction in the Collaborative Building of an Encyclopedia

International audienceOne of the major challenges of Applied Artificial Intelligence is to provide environments where high level human activities like learning, constructing theories or performing experiments, are enhanced by Artificial Intelligence technologies. This paper starts with the description of an ambitious project: EnCOrE2. The specific real world EnCOrE scenario, significantly representing a much wider class of potential applicative contexts, is dedicated to the building of an Encyclopedia of Organic Chemistry in the context of Virtual Communities of experts and students. Its description is followed by a brief survey of some major AI questions and propositions in relation with the problems raised by the EnCOrE project. The third part of the paper starts with some definitions of a set of “primitives” for rational actions, and then integrates them in a unified conceptual framework for the interactive construction of knowledge. To end with, we sketch out protocols aimed at guiding both the collaborative construction process and the collaborative learning process in the EnCOrE project.The current major result is the emerging conceptual model supporting interaction between human agents and AI tools integrated in Grid services within a socio-constructivist approach, consisting of cycles of deductions, inductions and abductions upon facts (the shared reality) and concepts (their subjective interpretation) submitted to negotiations, and finally converging to a socially validated consensus

Using Event Calculus to Formalise Policy Specification and Analysis

As the interest in using policy-based approaches for systems management grows, it is becoming increasingly important to develop methods for performing analysis and refinement of policy specifications. Although this is an area that researchers have devoted some attention to, none of the proposed solutions address the issues of analysing specifications that combine authorisation and management policies; analysing policy specifications that contain constraints on the applicability of the policies; and performing a priori analysis of the specification that will both detect the presence of inconsistencies and explain the situations in which the conflict will occur. We present a method for transforming both policy and system behaviour specifications into a formal notation that is based on event calculus. Additionally it describes how this formalism can be used in conjunction with abductive reasoning techniques to perform a priori analysis of policy specifications for the various conflict types identified in the literature. Finally, it presents some initial thoughts on how this notation and analysis technique could be used to perform policy refinement

Stylistic Creativity in the Utilization of Management Tools

We analyze the role of management instruments in the development of collective activity and in the dynamics of organization, recurring to pragmatic and semiotic theories. In dualist representation-based theories (rationalism, cognitivism), instruments are seen as symbolic reflections of situations, which enable actors to translate their complex concrete activities into computable models. In interpretation-based theories (pragmatism, theory of activity, situated cognition), instruments are viewed as signs interpreted by actors to make sense of their collective activity, in an ongoing and situated manner. Instruments combine objective artefacts and interpretive schemes of utilization. They constrain interpretation and utilization, but do not completely determine them: they define genus (generic classes) of collective activity, but they leave space for individual or local interpretive schemes and stylistic creation in using them. A major part of organizational dynamics takes place in the permanent interplay between instrumental genus and styles. Whereas representation-based theories can be acceptable approximations in stable and reasonably simple organizational settings, interpretation-based theories make uncertain and complex situations more intelligible. They view emotions and creativity as a key part of the interpretive process, rather than as external biases of a rational modelling process. For future research, we wish to study how interpretation-based theories should impact managerial practices and improve, not only intelligibility, but also actionability of instruments and situations.Collective Activity; Genus; Instruments; Interpretation; Management Instruments; Performance Management; Pragmatism; Semiotics; Style

Towards an interactive management approach to performance improvement in bureaucratic organization

Bibliography: p. 213-220.Organization science is not a new discipline. However, it persistently attracts many researchers to explore new concepts for coping with the increasing complexity in our society. The exploration is in transition, from mechanistic doctrine to systemic and humanistic notions. The mechanistic view is still prevailing and playing a dominant role, but, owing to its increasing critics, appeals for renovation of mechanistic principle incessantly arise. The tendency induces diversified approaches for intervening in the situation of bureaucratic context. This research investigates the features of organization from three angles - on the one hand, the structure and process (functional) aspects, and on the other, the purposeful behaviour of humans. Many works see the three components as separate, and deal with them accordingly. However, we contend that the three aspects are interrelated and that they should be integrated. The integration suggests that multiple views of organization are adequate because it embodies the attributes of purposeful behaviour and functional characteristics. Problems within an organization can be seen as the mutual influence of these parts. They can mutually aggravate and impede the performance of an organization. On the one hand, we contend that bureaucratic organization is inadequate, owing to its fragility in functional components of processing information to adapt to environment change. On the other hand, its rigid essence causes an inability to deal with human dimension problems. The problematical elements present a systemic relation. In turn, we attempt to explore the essence of organization's complex problems. The exploration concludes that both complexity and problems are cognitive phenomena. The illustrations suggest that the unearthing of organization problems should be grounded in the 'interaction' and 'consensus' 'model interchanging' of stakeholders. Based on this idea, we propose an intervention framework for diagnosing pathological pattern within bureaucratic organization. The framework is applied to one of South Africa's biggest local governments (the City of Tygerberg). The research result shows that the most significant problem within the City of Tygerberg is in the information-processing subsystem- associator. Besides, the 'mental pathology' locates on the 'sink' stage of the structured problem model

Eksaptatsioon: ühe bioloogilise mõiste semiootilise kirjelduse poole

Väitekirja elektrooniline versioon ei sisalda publikatsioone.Käesolev doktoritöö modelleerib eksaptatsiooni kui evolutsioonilist nähtust, lähtudes C.S. Peirce’i märgi- ja tuletusteooriast. Selle teostamiseks keskendub esimene osa “Enne eksaptatsiooni: eel-adapteerumine ja Chauncey Wright” mõiste tähendusele ning toob välja selle ulatusliku ajaloolise tausta. Erilist tähelepanu pööratakse C. Wrighti vanade jõudude uue kasutuse printsiibile ning tema intellektuaalsele seosele Darwiniga. Töö teine osa “Wright ja Peirce pragmatismist ja evolutsioonist” uurib Wright’i ja Peirce’i vahelisi sarnasusi ja erinevusi, pidades silmas Darwini teooria epistemoloogilist staatust, nende erinevat lähenemist Lamarck’i teooriatele ning evolutsionismi üldistamist bioloogiast teistesse valdkondadesse. Kolmas osa “Peirce’i evolutsionism: pidevuse ja ikoonilise abduktsiooni roll” käsitleb lähemalt evolutsiooni ning süvendab Peirce’i lamarkismi interpretatsiooni, rõhutades tema füsioloogilist tuletusteooria tõlgendust. Lisaks sellele näidatakse, et taju ning sarnasus on kesksed säärase raamistiku toimimiseks. Neljas osa (“Abduktsioon ja eksaptatsioon”) kasutab mitmeid mõisteid—asendatatvus, viga, kategooriate taju—,et teostada modelleerimist: eksaptatiivsed nähtused võivad järgida tajuliselt tingitud käitumismuutusi, põhinedes sarnasustel maailma üksuste vahel, mida tõlgendatakse ikooniliselt. Viies osa (“Tehnoloogilise arengu ikooniline ja eksaptatiivne loogika”) rakendab eeltoodut tehnoloogilise arengu valdkonnale ja tõestab, et kooptsioon on peamine mehhanism, millel baseeruvad nii abduktsioon kui eksaptatsioon. Kuues osa (“Vereimemise päritolu: evolutsioonilise abduktsiooni juhtum?”) on juhtumianalüüs ning siin pakutakse välja hüpotees, et hematofaagia võis tegelikult välja kujuneda abduktsiooni ja eksaptatsiooni integratsiooni läbi. Seitsmes (“Lõpumärkused juhtumianalüüsi kohta”) ja kaheksas (“Üldised järeldused”) osa selgitavad vastavalt spetsiifilisemaid ning üldisemaid doktoritöö tulemusi.The present dissertation attempts a modeling of the evolutionary phenomenon of exaptation according to C. S. Peirce’s theory of signs and inference. To accomplish this, the first section (“Before exaptation: preadaptation and Chauncey Wright”) focuses on the meaning of the concept and reveals its vast historical background. Special attention is paid to C. Wright’s principle of new uses of old powers and his intellectual relationship with Darwin. The second section (“Wright and Peirce on pragmatism and evolution”) investigates then similarities and differences between Wright and Peirce, especially insofar the epistemological status of Darwin’s theory, their different approach to Lamarck’s account and the issue of evolutionism as a generalization from biology to other fields are concerned. The third section (“Peirce’s evolutionism: the role of continuity and iconic abduction”) further elaborates on evolution and deepens Peirce’s interpretation of Lamarckism by emphasizing his physiological translation of the theory of inference; besides, the role played by perception and similarity is considered central to the working of such framework. The fourth section (“Abduction and exaptation”) exploits several concepts — substitutability, mistake, categorical perception — to set up properly the modeling: exaptive phenomena can follow sensory-driven changes of behavior, based on similarities among world entities that are interpreted iconically. The fifth section (“The iconic and exaptive logic of technological development”) applies what previously achieved to the issue of technological development and corroborates the idea of cooption as the basic mechanism underlying both abduction and exaptation. The sixth section (“The origin of bloodsucking: a case of evolutionary abduction?”) is a case study and puts forward the hypothesis that hematophagy might actually have originated through a process integrating abduction and exaptation. The seventh (“Concluding remarks on the case study”) and eight sections (“General conclusions”) explain accordingly specific and general findings of the thesis

Exploring ‘People’ as the key element in enterprise architecture implementation: A Critical Realist Perspective

TOGAF (2009) describes the purpose of Enterprise Architecture (EA) is to optimise enterprisewide systems - the often-fragmented legacy of data processes (both manual and automated) - into an integrated environment that is responsive to change and supports the delivery of the business strategy (The Open Group Architecture Framework [TOGAF], 2009). However, for a number of reasons organisations still have difficulties establishing an effective EA (Raadt & Vliet, 2008; Gartner, 2009; and Janssen & Klievink, 2012, among others) and various reports suggest up to two thirds of implementations do not fulfil expectations (Roeleven, 2010). Being organisation wide with a strong governance element EA has significant social implications and social dependence, yet many implementations wrongly treat EA as solely a technical program. This thesis argues that the lack of focus on the ‘people’ element of EA could be the reason why many organisations still struggle with EA implementation. Recognising the importance of people in EA implementation requires acceptance of implementation as a social program, heavily influenced by the structural and cultural systems surrounding the architecture. In order to address the need for greater recognition of the role of people and the social aspects of EA implementation, this thesis adopts critical realism (CR) and its most recognised methodology, the morphogenetic approach (MA). Realism emphasises ontology and strongly argues that ontology, methodology and epistemology are closely linked – as Fleetwood (2005, p. 197) suggests, ontology matters: “The way we think the world is (ontology) influences: what we think can be known about it (epistemology); how we think it can be investigated (methodology and research techniques); the kinds of theories we think can be constructed about it; and the political and policy stances we are prepared to take”. In order to examine the social implications of technology implementation it makes sense to adopt a wellrecognized social theory like critical realism. This social realist approach proposes an analytical separation between structure, culture and agency (people) in order to examine their interactions over time. The MA suggests three important cycles – structural conditioning, social interaction and structural elaboration that provide a platform for examining possible change. Archer also importantly suggests that the emergent properties of collectivities and individuals differ. Such a model has clear value for examining the “people” acceptance of the new impositions and opportunities provided by the EA implementation. It acknowledges the sociocultural consequences of interactions between the structure and the culture to provide particular situational logics that direct, but do not determine the actions of people. The MA emphasises strongly the role of time in situation examination suggesting that structure and culture predate subsequent actions by involved agents. The thesis describes particular situational logics or mechanisms emanating from the interaction between structural and cultural systems that encourage particular behaviours in response to the EA program. These actions are then further examined in the sequence of MA cycles. Since mechanisms are only effective if people adopt them or not, another important element in this study is the part played by “reflexivity”. Reflexivity highlights the linkage between people concerns, projects and practices as people act in order to promote their concerns, and form projects to advance or to protect what they care about most. Reflexivity is an important mechanism for explaining how people’s ultimate concerns impact on their approach to the impositions of EA. An Australian university implementing EA (termed UX for anonymity) has been used as a case study in this research – this fortuitous timing allowed a careful and detailed examination of implementation over a 3-year period from initial rollout to ultimate acceptance. The study describes the challenging environment of university implementation where “academic freedom” is paramount and individual and group autonomies are threatened by EA – the study presents the important mechanisms and situational logics that direct people’s actions within the complex social context of a university. Semi-structured in-depth interviews were used as the primary method of data collection across UX stakeholders. A range of interviews were held throughout the study period with the university IT Governance Committee, the University Architecture Board, the CIO, and the Enterprise Business Group, as well as individual end-users such as teaching staff, researchers, students, and administrative staff of the faculties, schools and service centres. The MA provided a basic structure for unravelling the social complexity and helped guide the interview questions to identify the generative mechanisms hidden in the real domain, and to highlight the conditions that encourage individual and collective acceptance of EA practices. The reflexivity indicator developed by Archer –ICONI– is used throughout to explain how personal projects are formed and how they mediate the exercise of structural/cultural constraints and enablement within EA implementation. Passive participation in regular EA implementation meetings at UX was also important and useful to unearth possible perceived causal possibilities emanating from within the program itself and evident within the social context of implementation. Underpinned by a critical realist perspective, the thesis demonstrates that the MA is a powerful analytical tool to uncover the hidden mechanisms (the situational logics of structures and cultures) and social responses that enable success of EA implementation. The research examines the particular situational logics evident within the University under study and how these provide opportunities and constraints to the acceptance of EA over time. Equally important was reflexivity theory in attaining knowledge and understanding about what it is about people’s internal relations that makes EA implementation succeed. This thesis offers organisations a means to focus on the deeper issues of EA implementation programs by understanding the social complexity surrounding the architecture. The recognition of people as a key element in EA implementation provides a useful explanation of how the key stakeholders (and their power, influence and interests) may constrain and enable EA implementation. By including reflexivity as an important mechanism, organisations will be in a better position to understand the role of people and their interactions with preexisting structures and cultures operating over different time periods – reflexivity suggesting that “people” always have the possibility to do otherwise than expected, largely dependent on their personal history and their current personal projects and ultimate concerns

Formal verification of AI software

The application of formal verification techniques to Artificial Intelligence (AI) software, particularly expert systems, is investigated. Constraint satisfaction and model inversion are identified as two formal specification paradigms for different classes of expert systems. A formal definition of consistency is developed, and the notion of approximate semantics is introduced. Examples are given of how these ideas can be applied in both declarative and imperative forms