Modelling Concurrency with Comtraces and Generalized Comtraces

Comtraces (combined traces) are extensions of Mazurkiewicz traces that can model the "not later than" relationship. In this paper, we first introduce the novel notion of generalized comtraces, extensions of comtraces that can additionally model the "non-simultaneously" relationship. Then we study some basic algebraic properties and canonical reprentations of comtraces and generalized comtraces. Finally we analyze the relationship between generalized comtraces and generalized stratified order structures. The major technical contribution of this paper is a proof showing that generalized comtraces can be represented by generalized stratified order structures.Comment: 49 page

Poverty Dynamics: Measurement and Understanding from an Interdisciplinary Perspective

This paper introduces a significant new multi-disciplinary collection of studies of poverty dynamics, presenting the reader with the latest thinking by a group of researchers who are leaders in their respective disciplines. It argues that there are three main fronts on which progress must be made if we are to dramatically deepen the understanding of why poverty occurs, and significantly improve the effectiveness of poverty reduction policies. First, poverty research needs to focus on poverty dynamics — over the life-course, across generations and between different social groups. Second, there is a need to move efforts to measure poverty dynamics beyond mere income and consumption to more multidimensional concepts and measures of poverty. This is increasingly common in static analyses but is rare in work on poverty dynamics. Third, at the same time there is a growing consensus that a thorough understanding of poverty and poverty reduction requires bridging the gap between disciplines through interdisciplinary approaches that combine qualitative and quantitative methods in measurement and analysis.poverty dynamics, multidimensional concepts and measures, interdisciplinary approaches, Food Security and Poverty, International Development, Political Economy, Public Economics,

An Integrated Approach for the Specification and Analysis of Stochastic Real-Time Systems

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Nutrient criteria to achieve New Zealand’s riverine macroinvertebrate targets

Waterways worldwide are experiencing nutrient enrichment from population growth and intensive agriculture, and New Zealand is part of this global trend. Increasing fertilizer in New Zealand and intensive agriculture have driven substantial water quality declines over recent decades. A recent national directive has set environmental managers a range of riverine ecological targets, including three macroinvertebrate indicators, and requires nutrient criteria be set to support their achievement. To support these national aspirations, we use the minimization-of-mismatch analysis to derive potential nutrient criteria. Given that nutrient and macroinvertebrate monitoring often does not occur at the same sites, we compared nutrient criteria derived at sites where macroinvertebrates and nutrients are monitored concurrently with nutrient criteria derived at all macroinvertebrate monitoring sites and using modelled nutrients. To support all three macroinvertebrate targets, we suggest that suitable nutrient criteria would set median dissolved inorganic nitrogen concentrations at ~0.6 mg/L and median dissolved reactive phosphorus concentrations at ~0.02 mg/L. We recognize that deriving site-specific nutrient criteria requires the balancing of multiple values and consideration of multiple targets, and anticipate that criteria derived here will help and support these environmental goals

Contextual meanings: an investigation of their persuasive power in research article introductions

The thesis explores the persuasive power of contextualisaton in research article (RA) introductions. Contextualisation is understood within the framework of systemic functional grammar (SFL). It refers to the interpersonal working of meanings at the interface of discourse semantics and lexicogrammar, as these meanings frame and shape discourse participants and processes, to evoke particular understandings that serve the text's social purpose. A corpus of six RA introductions from the disciplines of history, social science and inorganic chemistry was selected. Analysis included transitivity, periodicity, Theme and appraisal. The thesis argues that in the corupus, contextual meanings fulfil crucial interpersonal tasks, such as framing inquiry, engaging communities, establishing research importance and foregrounding critical issues. Findings suggest contextual meanings work in several ways, with varying densities and on multiple levels, to create interpersonal impacts. Analysis indicates the conglomeration of contextual meanings at particular points is a significant indication of persuasive risk, where precise meaning is required, such as in research claims. It is intended the research will be pedagogically useful in informing development of resources for students who struggle with academic English and experience difficulty, and even failure, in effectively foregrounding their work

A methodology for the requirements analysis of critical real-time systems

PhD ThesisThis thesis describes a methodology for the requirements analysis of critical real-time systems. The methodology is based on formal methods, and provides a systematic way in which requirements can be analysed and specifications produced. The proposed methodology consists of a framework with distinct phases of analysis, a set oftechniques appropriate for the issues to be analysed at each phase of the framework, a hierarchical structure of the specifications obtained from the process of analysis, and techniques to perform quality assessment of the specifications. The phases of the framework, which are abstraction levels for the analysis of the requirements, follow directly from a general structure adopted for critical real-time systems. The intention is to define abstraction levels, or domains, in which the analysis of requirements can be performed in terms of specific properties of the system, thus reducing the inherent complexity of the analysis. Depending on the issues to be analysed in each domain, the choice of the appropriate formalism is determined by the set of features, related to that domain, that a formalism should possess. In this work, instead of proposing new formalisms we concentrate on identifying and enumerating those features that a formalism should have. The specifications produced at each phase of the framework are organised by means of a specification hierarchy, which facilitates our assessment of the quality of the requirements specifications, and their traceability. Such an assessment should be performed by qualitative and quantitative means in order to obtain high confidence (assurance) that the level of safety is acceptable. In order to exemplify the proposed methodology for the requirements analysis of critical real-time systems we discuss a case study based on a crossing of two rail tracks (in a model railway), which raises safety issues that are similar to those found at a traditional level crossing (i.e. rail-road)CAPES/Ministry of Education (Brazil

An Approach to Ecosystem-Based Fishery Management

Marine scientists and policymakers are encouraging ecosystem-based fishery management (EBFM), but there is limited guidance on how to operationalize the concept. We adapt financial portfolio theory as a method for EBFM that accounts for species interdependencies, uncertainty, and sustainability constraints. Illustrating our method with routinely collected data available from the Chesapeake Bay, we demonstrate the gains from taking into account species variances and covariances in setting species total allowable catches. We find over the period from 1962–2003 that managers could have increased the revenues from fishing and reduced the variance by employing ecosystem frontiers in setting catch levels.ecosystem-based fishery management, portfolio, trophic modeling, precaution

Application of expert systems in project management decision aiding

The feasibility of developing an expert systems-based project management decision aid to enhance the performance of NASA project managers was assessed. The research effort included extensive literature reviews in the areas of project management, project management decision aiding, expert systems technology, and human-computer interface engineering. Literature reviews were augmented by focused interviews with NASA managers. Time estimation for project scheduling was identified as the target activity for decision augmentation, and a design was developed for an Integrated NASA System for Intelligent Time Estimation (INSITE). The proposed INSITE design was judged feasible with a low level of risk. A partial proof-of-concept experiment was performed and was successful. Specific conclusions drawn from the research and analyses are included. The INSITE concept is potentially applicable in any management sphere, commercial or government, where time estimation is required for project scheduling. As project scheduling is a nearly universal management activity, the range of possibilities is considerable. The INSITE concept also holds potential for enhancing other management tasks, especially in areas such as cost estimation, where estimation-by-analogy is already a proven method