Investigation into an improved modular rule-based testing framework for business rules

Rule testing in scheduling applications is a complex and potentially costly business problem. This thesis reports the outcome of research undertaken to develop a system to describe and test scheduling rules against a set of scheduling data. The overall intention of the research was to reduce commercial scheduling costs by minimizing human domain expert interaction within the scheduling process. This thesis reports the outcome of research initiated following a consultancy project to develop a system to test driver schedules against the legal driving rules in force in the UK and the EU. One of the greatest challenges faced was interpreting the driving rules and translating them into the chosen programming language. This part of the project took considerable effort to complete the programming, testing and debugging processes. A potential problem then arises if the Department of Transport or the European Union alter or change the driving rules. Considerable software development is likely to be required to support the new rule set. The approach considered takes into account the need for a modular software component that can be used in not just transport scheduling systems which look at legal driving rules but may also be integrated into other systems that have the need to test temporal rules. The integration of the rule testing component into existing systems is key to making the proposed solution reusable. The research outcome proposes an alternative approach to rule definition, similar to that of RuleML, but with the addition of rule metadata to provide the ability of describing rules of a temporal nature. The rules can be serialised and deserialised between XML (eXtensible Markup Language) and objects within an object oriented environment (in this case .NET with C#), to provide a means of transmission of the rules over a communication infrastructure. The rule objects can then be compiled into an executable software library, allowing the rules to be tested more rapidly than traditional interpreted rules. Additional support functionality is also defined to provide a means of effectively integrating the rule testing engine into existing applications. Following the construction of a rule testing engine that has been designed to meet the given requirements, a series of tests were undertaken to determine the effectiveness of the proposed approach. This lead to the implementation of improvements in the caching of constructed work plans to further improve performance. Tests were also carried out into the application of the proposed solution within alternative scheduling domains and to analyse the difference in computational performance and memory usage across system architectures, software frameworks and operating systems, with the support of Mono. Future work that is expected to follow on from this thesis will likely reside in investigations into the development of graphical design tools for the creation of the rules, improvements in the work plan construction algorithm, parallelisation of elements of the process to take better advantage of multi-core processors and off-loading of the rule testing process onto dedicated or generic computational processors

Time series forecasting by means of evolutionary algorithms

IEEE International Parallel and Distributed Processing Symposium. Long Beach, CA, 26-30 March 2007Many physical and artificial phenomena can be described by time series. The prediction of such phenomenon could be as complex as interesting. There are many time series forecasting methods, but most of them only look for general rules to predict the whole series. The main problem is that time series usually have local behaviours that don't allow forecasting the time series by general rules. In this paper, a new method for finding local prediction rules is presented. Those local prediction rules can attain a better general prediction accuracy. The method presented in this paper is based on the evolution of a rule system encoded following a Michigan approach. For testing this method, several time series domains have been used: a widely known artificial one, the Mackey-Glass time series, and two real world ones, the Venice Lagon and the sunspot time series

Interaction with rule-bound systems : introducing a new 'ideal type' problem context

This PhD thesis introduces a new ideal-type problem context of rule-bound systems. The thesis has been generated through a belief in the ability of metaphor to make the abstract visible, its capacity to make the unfamiliar familiar, and its effectiveness as a legitimate means of generating insight and organizing knowledge. Metaphorical description remains an integral part of this thesis from beginning to end.It shows how the new context of rule-bound systems provides closure of the ideal problem context grid along the participants access. Following the ideas that created the basis for this closure, insight into a new role for systems practitioners is provided and the ideal problem context grid developed to form of a Torus.Part 1 outlines the theoretical foundations and other inspirations that underpin the thesis. Grounded on a wider definition of rules, including rules in both a formal and informal sense, multiple ways of viewing rules are highlighted. The characteristics of rule-bound systems are identified, drawing comparisons with other 'ideal-types'. Suggestions are also drawn out as to how change might be affected in a rule-bound context. Part II of this thesis is an account of a real world intervention informed by Critical Systems Thinking, carried out under the auspices of Participatory Action Research. A number of systems research methods and concepts were employed to investigate the participation of students in policy making in two contrasting senior schools in the North of England - organizations believed to present many of the characteristics of the rule-bound system. The approach used was one mixing methods, specifically, the creation of a symbiotic relationship between Soft Systems Methodology and Critical Systems Heuristics. Part III describes the process of reflection undertaken and the conclusion to the thesis

Stuck in the moment: cognitive inflexibility in preschoolers following an extended time period

Preschoolers display surprising inflexibility in problem solving, but seem to approach new challenges with a fresh slate. We provide evidence that while the former is true the latter is not. Here, we examined whether brief exposure to stimuli can influence children’s problem solving following several weeks after first exposure to the stimuli. We administered a common executive function task, the Dimensional Change Card Sort, which requires children to sort picture cards by one dimension (e.g., color) and then switch to sort the same cards by a conflicting dimension (e.g., shape). After a week or after a month delay, we administered the second rule again. We found that 70% of preschoolers continued to sort by the initial sorting rule, even after a month delay, and even though they are explicitly told what to do. We discuss implications for theories of executive function development, and for classroom learning

The still-Life density problem and its generalizations

A "still Life" is a subset S of the square lattice Z^2 fixed under the transition rule of Conway's Game of Life, i.e. a subset satisfying the following three conditions: 1. No element of Z^2-S has exactly three neighbors in S; 2. Every element of S has at least two neighbors in S; 3. Every element of S has at most three neighbors in S. Here a ``neighbor'' of any x \in Z^2 is one of the eight lattice points closest to x other than x itself. The "still-Life conjecture" is the assertion that a still Life cannot have density greater than 1/2 (a bound easily attained, for instance by {(x,y): x is even}). We prove this conjecture, showing that in fact condition 3 alone ensures that S has density at most 1/2. We then consider variations of the problem such as changing the number of allowed neighbors or the definition of neighborhoods; using a variety of methods we find some partial results and many new open problems and conjectures.Comment: 29 pages, including many figures drawn as LaTeX "pictures

Peer Processes and Adolescent Behaviour

While research suggests that peer influence can lead to increases in undesirable behaviours of adolescents, there has been little focus on the specific mechanisms of influence. A relatively small literature examining social interactions between peers has found that the discussion of rule breaking topics by pairs of boys relates to how much problem behaviour the boys engage in. This research is limited by its reliance on a set of similar samples from a North American population base. This thesis explored the relationship between social interaction and behaviour with sample from New Zealand Aotearoa. Nine pairs of Year 10 boys were recruited primarily from two high schools. A half-hour conversation was video taped for each pair. These conversations were coded on the basis of the nature of the talk between pairs of participants following the coding system proposed by Poe, Dishion, Griesler and Andrews (1990). The coded behaviours were analysed and compared to measures of previous rule breaking behaviours. The duration of rule breaking talk was found to correlate with the level of previous rule breaking behaviour. It was not clear whether the amount of rule breaking talk was related to the amount of laughter following it. Possible explanations are discussed. While generalisations from these results are limited by an unexpectedly small sample size, they show similarity to the previous research findings. The findings, the difficulties in recruitment to the research and the implications of these for future research are discussed

Characterization and computation of restless bandit marginal productivity indices

The Whittle index [P. Whittle (1988). Restless bandits: Activity allocation in a changing world. J. Appl. Probab. 25A, 287-298] yields a practical scheduling rule for the versatile yet intractable multi-armed restless bandit problem, involving the optimal dynamic priority allocation to multiple stochastic projects, modeled as restless bandits, i.e., binary-action (active/passive) (semi-) Markov decision processes. A growing body of evidence shows that such a rule is nearly optimal in a wide variety of applications, which raises the need to efficiently compute the Whittle index and more general marginal productivity index (MPI) extensions in large-scale models. For such a purpose, this paper extends to restless bandits the parametric linear programming (LP) approach deployed in [J. Niño-Mora. A (2/3)$n^{3}$ fast-pivoting algorithm for the Gittins index and optimal stopping of a Markov chain, INFORMS J. Comp., in press], which yielded a fast Gittins-index algorithm. Yet the extension is not straightforward, as the MPI is only defined for the limited range of socalled indexable bandits, which motivates the quest for methods to establish indexability. This paper furnishes algorithmic and analytical tools to realize the potential of MPI policies in largescale applications, presenting the following contributions: (i) a complete algorithmic characterization of indexability, for which two block implementations are given; and (ii) more importantly, new analytical conditions for indexability — termed LP-indexability — that leverage knowledge on the structure of optimal policies in particular models, under which the MPI is computed faster by the adaptive-greedy algorithm previously introduced by the author under the more stringent PCL-indexability conditions, for which a new fast-pivoting block implementation is given. The paper further reports on a computational study, measuring the runtime performance of the algorithms, and assessing by a simulation study the high prevalence of indexability and PCL-indexability.