Lógica formal y argumentación

Este artículo explora críticamente la tesis según la cual la lógica formal deductiva contemporánea proporciona métodos e instrumentos para una teoría de la evaluación de argumentos formulados en un lenguaje natural. En este artículo se sostiene que la teoría de la (in)validez de la lógica formal deductiva sólo se puede aplicar a los argumentos del lenguaje natural utilizando aquello que se quiere explicar teóricamente, i.e. Las intuiciones que los/las hablantes de un lenguaje natural tienen acerca de la relaciones de implicación lógica entre las expresiones de esa lengua. Se exploran también algunas consecuencias pedagógicas de esta crítica.

Lógica formal y argumentación

Este artículo explora críticamente la tesis según la cual la lógica formal deductiva contemporánea proporciona métodos e instrumentos para una teoría de la evaluación de argumentos formulados en un lenguaje natural. En este artículo se sostiene que la teoría de la (in)validez de la lógica formal deductiva sólo se puede aplicar a los argumentos del lenguaje natural utilizando aquello que se quiere explicar teóricamente, i.e. Las intuiciones que los/las hablantes de un lenguaje natural tienen acerca de la relaciones de implicación lógica entre las expresiones de esa lengua. Se exploran también algunas consecuencias pedagógicas de esta crítica.

Lógica formal y argumentación

Este artículo explora críticamente la tesis según la cual la lógica formal deductiva contemporánea proporciona métodos e instrumentos para una teoría de la evaluación de argumentos formulados en un lenguaje natural. En este artículo se sostiene que la teoría de la (in)validez de la lógica formal deductiva sólo se puede aplicar a los argumentos del lenguaje natural utilizando aquello que se quiere explicar teóricamente, i.e. Las intuiciones que los/las hablantes de un lenguaje natural tienen acerca de la relaciones de implicación lógica entre las expresiones de esa lengua. Se exploran también algunas consecuencias pedagógicas de esta crítica.

An abstract machine based execution model for computer architecture design and efficient implementation of logic programs in parallel.

The term "Logic Programming" refers to a variety of computer languages and execution models which are based on the traditional concept of Symbolic Logic. The expressive power of these languages offers promise to be of great assistance in facing the programming challenges of present and future symbolic processing applications in Artificial Intelligence, Knowledge-based systems, and many other areas of computing. The sequential execution speed of logic programs has been greatly improved since the advent of the first interpreters. However, higher inference speeds are still required in order to meet the demands of applications such as those contemplated for next generation computer systems. The execution of logic programs in parallel is currently considered a promising strategy for attaining such inference speeds. Logic Programming in turn appears as a suitable programming paradigm for parallel architectures because of the many opportunities for parallel execution present in the implementation of logic programs. This dissertation presents an efficient parallel execution model for logic programs. The model is described from the source language level down to an "Abstract Machine" level suitable for direct implementation on existing parallel systems or for the design of special purpose parallel architectures. Few assumptions are made at the source language level and therefore the techniques developed and the general Abstract Machine design are applicable to a variety of logic (and also functional) languages. These techniques offer efficient solutions to several areas of parallel Logic Programming implementation previously considered problematic or a source of considerable overhead, such as the detection and handling of variable binding conflicts in AND-Parallelism, the specification of control and management of the execution tree, the treatment of distributed backtracking, and goal scheduling and memory management issues, etc. A parallel Abstract Machine design is offered, specifying data areas, operation, and a suitable instruction set. This design is based on extending to a parallel environment the techniques introduced by the Warren Abstract Machine, which have already made very fast and space efficient sequential systems a reality. Therefore, the model herein presented is capable of retaining sequential execution speed similar to that of high performance sequential systems, while extracting additional gains in speed by efficiently implementing parallel execution. These claims are supported by simulations of the Abstract Machine on sample programs.

Probabilistic languages and automata.

Vita.

An implementation of a system for the formal definition of programming languages /

Originally presented as the author's thesis, University of Illinois at Urbana-Champaign.

The development of hard real-time systems using a formal approach

Hard real-time systems are a class of computer control systems that must react to demands of their environment by providing `correct' and timely responses. Since these systems are increasingly being used in systems with safety implications, it is crucial that they are designed and developed to operate in a correct manner. This thesis is concerned with developing formal techniques that allow the specification, verification and design of hard real-time systems. Formal techniques for hard real-time systems must be capable of capturing the system's functional and performance requirements, and previous work has proposed a number of techniques which range from the mathematically intensive to those with some mathematical content. This thesis develops formal techniques that contain both an informal and a formal component because it is considered that the informality provides ease of understanding and the formality allows precise specification and verification. Specifically, the combination of Petri nets and temporal logic is considered for the specification and verification of hard real-time systems. Approaches that combine Petri nets and temporal logic by allowing a consistent translation between each formalism are examined. Previously, such techniques have been applied to the formal analysis of concurrent systems. This thesis adapts these techniques for use in the modelling, design and formal analysis of hard real-time systems. The techniques are applied to the problem of specifying a controller for a high-speed manufacturing system. It is shown that they can be used to prove liveness and safety properties, including qualitative aspects of system performance. The problem of verifying quantitative real-time properties is addressed by developing a further technique which combines the formalisms of timed Petri nets and real-time temporal logic. A unifying feature of these techniques is the common temporal description of the Petri net. A common problem with Petri net based techniques is the complexity problems associated with generating the reachability graph. This thesis addresses this problem by using concurrency sets to generate a partial reachability graph pertaining to a particular state. These sets also allows each state to be checked for the presence of inconsistencies and hazards. The problem of designing a controller for the high-speed manufacturing system is also considered. The approach adopted mvolves the use of a model-based controller: This type of controller uses the Petri net models developed, thus preservIng the properties already proven of the controller. It. also contains a model of the physical system which is synchronised to the real application to provide timely responses. The various way of forming the synchronization between these processes is considered and the resulting nets are analysed using concurrency sets.

A Mathematical Apparatus for Domain Ontology Simulation. An Extendable Language of Applied Logic

* This paper was made according to the program of fundamental scientific research of the Presidium of the Russian Academy of Sciences «Mathematical simulation and intellectual systems», the project "Theoretical foundation of the intellectual systems based on ontologies for intellectual support of scientific researches".

Formal methods for the development and verification of autonomic IT systems

This chapter explores ways in which rigorous mathematical techniques, termed formal methods, can be employed to improve the predictability and dependability of autonomic computing. Model checking, formal specification, and quantitative verification are presented in the contexts of conflict detection in autonomic computing policies, and of implementation of goal and utility-function policies in autonomic IT systems, respectively. Each of these techniques is illustrated using a detailed case study, and analysed to establish its merits and limitations. The analysis is then used as a basis for discussing the challenges and opportunities of this endeavour to transition the development of autonomic IT systems from the current practice of using ad-hoc methods and heuristic towards a more principled approach. © 2012, IGI Global.

Detecting and resolving redundancies in EP3P policies

Current regulatory requirements on data privacy make it increasingly important for enterprises to be able to verify and audit their compliance with their privacy policies. Traditionally, a privacy policy is written in a natural language. Such policies inherit the potential ambiguity, inconsistency and mis-interpretation of natural text. Hence, formal languages are emerging to allow a precise specification of enforceable privacy policies that can be verified. The EP3P language is one such formal language. An EP3P privacy policy of an enterprise consists of many rules. Given the semantics of the language, there may exist some rules in the ruleset which can never be used, these rules are referred to as redundant rules. Redundancies adversely affect privacy policies in several ways. Firstly, redundant rules reduce the efficiency of operations on privacy policies. Secondly, they may misdirect the policy auditor when determining the outcome of a policy. Therefore, in order to address these deficiencies it is important to identify and resolve redundancies. This thesis introduces the concept of minimal privacy policy - a policy that is free of redundancy. The essential component for maintaining the minimality of privacy policies is to determine the effects of the rules on each other. Hence, redundancy detection and resolution frameworks are proposed. Pair-wise redundancy detection is the central concept in these frameworks and it suggests a pair-wise comparison of the rules in order to detect redundancies. In addition, the thesis introduces a policy management tool that assists policy auditors in performing several operations on an EP3P privacy policy while maintaining its minimality. Formal results comparing alternative notions of redundancy, and how this would affect the tool, are also presented.

Printmaking as an expanding field in contemporary art practice : a case study of Japan, Australia and Thailand

This thesis proposes that contemporary printmaking, at its most significant, marks the present through reconstructing pasts and anticipating futures. It argues this through examples in the field, occurring in contexts beyond the Euramerican (Europe and North America). The arguments revolve around how the practice of a number of significant artists in Japan, Australia and Thailand has generated conceptual and formal innovations in printmaking that transcend local histories and conventions, whilst paradoxically, also building upon them and creating new meanings. The arguments do not portray the relations between contemporary and traditional art as necessarily antagonistic but rather, as productively dialectical. Furthermore, the case studies demonstrate that, in the 1980s and 1990s particularly, the studio practice of these printmakers was informed by other visual arts disciplines and reflected postmodern concerns. Departures from convention witnessed in these countries within the Asia-Pacific region shifted the field of the print into a heterogeneous and hybrid realm. The practitioners concerned (especially in Thailand) produced work that was more readily equated with performance and installation art than with printmaking per se. In Japan, the incursion of photography interrupted the decorative cast of printmaking and delivered it from a straightforward, craft-based aesthetic. In Australia, fixed notions of national identity were challenged by print practitioners through deliberate cultural rapprochements and technical contradictions (speaking across old and new languages).However time-honoured print methods were not jettisoned by any case study artists. Their re-alignment of the fundamental attributes of printmaking, in line with materialist formalism, is a core consideration of my arguments. The artists selected for in-depth analysis from these three countries are all innovators whose geographical circumstances and creative praxis drew on local traditions whilst absorbing international trends. In their radical revisionism, they acknowledged the specificity of history and place, conditions of contingency and forces of globalisation. The transformational nature of their work during the late twentieth century connects it to the postmodern ethos and to a broader artistic and cultural nexus than has hitherto been recognised in literature on the print. Emerging from former guild-based practices, they ambitiously conceived their work to be part of a continually evolving visual arts vocabulary. I argue in this thesis that artists from the Asia-Pacific region have historically broken with the hermetic and Euramerican focus that has generally characterised the field. Inadequate documentation and access to print activity outside the dominant centres of critical discourse imply that readings of postmodernism have been too limited in their scope of inquiry. Other locations offer complexities of artistic practice where re-alignments of customary boundaries are often the norm. By addressing innovative activity in Japan, Australia and Thailand, this thesis exposes the need for a more inclusive theoretical framework and wider global reach than currently exists for ‘printmaking’.

Contextualising the teaching and learning of measurement within Torres Strait Islander schools

A one year mathematics project that focused on measurement was conducted with six Torres Strait Islander schools and communities. Its key focus was to contextualise the teaching and learning of measurement within the students’ culture, communities and home languages. There were six teachers and two teacher aides who participated in the project. This paper reports on the findings from the teachers’ and teacher aides’ survey questionnaire used in the first Professional Development session to identify: a) teachers’ experience of teaching in Torres Strait Islands, b) teachers’ beliefs about effective ways to teach Torres Strait Islander students, and c) contexualising measurement within Torres Strait Islander culture, Communities and home languages. A wide range of differing levels of knowledge and understanding about how to contextualise measurement to support student learning were identified and analysed. For example, an Indigenous teacher claimed that mathematics and the environment are relational, that is, they are not discrete and in isolation from one another, rather they interconnect with mathematical ideas emerging from the environment of the Torres Strait Communities.

An analytical solution for diffusion and nonlinear uptake of oxygen in a spherical cell

We develop a new analytical solution for a reactive transport model that describes the steady-state distribution of oxygen subject to diffusive transport and nonlinear uptake in a sphere. This model was originally reported by Lin (Journal of Theoretical Biology, 1976 v60, pp449–457) to represent the distribution of oxygen inside a cell and has since been studied extensively by both the numerical analysis and formal analysis communities. Here we extend these previous studies by deriving an analytical solution to a generalized reaction-diffusion equation that encompasses Lin’s model as a particular case. We evaluate the solution for the parameter combinations presented by Lin and show that the new solutions are identical to a grid-independent numerical approximation.

Languages of Communication : Indigenous language and/or English?

My interest in producing this paper on Indigenous languages was borne out of conversations with and learnings from community members in the Torres Straits and those connected to the ‘Dream Circle’. Nakata (2003, p. 12) laments the situation whereby ‘teachers are transitionary and take their hard-earned knowledge with them when they leave’. I am thus responding to the call to add to the conversation in a productive albeit culturally loaded way. To re-iterate, I am neither Indigenous nor am I experienced in teaching and learning in these contexts. As problematic as these two points are, I am in many ways typical of the raft of inexperienced white Australian teachers assigned to positions in school contexts where Indigenous students are enrolled or in mainstream contexts with substantial populations of Indigenous students. By penning this article, it is neither my intention to contribute to the silencing of Indigenous educators or Indigenous communities. My intention is to articulate my teacherly reflections as they apply to the topic under discussion. The remainder of this paper is presented in three sections. The next section provides a brief overview of the number of Indigenous people and Indigenous languages in Australia and the role of English as a language of communication. The section which follows draws on theorisations from second/additional language acquisition to overview three different schools of thought about the consequences of English in the lives of Indigenous Australians. The paper concludes by considering the tensions for inexperienced white Australian teachers caught up in the fray.