AGATHA: Using heuristic search to automate the construction of case law theories

In this paper we describe AGATHA, a program designed to automate the process of theory construction in case based domains. Given a seed case and a number of precedent cases, the program uses a set of argument moves to generate a search space for a dialogue between the parties to the dispute. Each move is associated with a set of theory constructors, and thus each point in the space can be associated with a theory intended to explain the seed case and the other cases in the domain. The space is large and so an heuristic search method is needed. This paper describes two methods based on A* and alpha/beta pruning and also a series of experiments designed to explore the appropriateness of different evaluation functions, the most useful precedents to use as seed cases and the quality of the resulting theories.     

Acute cardio-respiratory changes induced by hyperpnoea using a respiratory muscle trainer

The aim of this study was to examine the cardio-respiratory effects of voluntary hyperpnoea using a respiratory muscle trainer (RMT) with three different sized rebreathing bags. In particular, the effects of hyperpnoea on inspired and end-tidal gas concentrations were determined. Seven adult males completed three 30 min bouts of hyperpnoea using optimal, oversized and undersized rebreathing bags. Inspired (F(I)) and expired end-tidal (F(ET)) O2 and CO2 concentrations, arterial O2 saturation (S(AO2)) and heart rate were measured during hyperpnoea. Before and after a bout of hyperpnoea, pulmonary function and blood pressure (BP) were assessed. Data were analysed using a two-way repeated-measures ANOVA, with p < 0.05 considered significant. Three subjects experienced discomfort during hyperpnoea and stopped after 20 min. During hyperpnoea, the F(ETCO2) was maintained at 4.6 +/- 0.7% irrespective of bag size. The increase in F(ICO2) over time reached 0.5 +/- 0.5% at 20 min. The F(IO2) fell to 19.4 +/- 0.8% at 20 min, and S(AO2) decreased to 97%. Heart rate and systolic BP increased slightly, but independently of rebreathing bag volume. No changes in pulmonary function or diastolic BP were found. It is concluded that the RMT maintained a constant F(ETCO2) at the expense of a mild hypoxia. The acute effects of hyperpnoea on the cardio-respiratory system are generally mild, but not always tolerable for 30 min.     

Using argumentation to model agent decision making in economic experiments

In this paper we demonstrate how a qualitative framework for decision making can be used to model scenarios from experimental economic studies and we show how our approach explains the results that have been reported from such studies. Our framework is an argumentation-based one in which the social values promoted or demoted by alternative action options are explicitly represented. Our particular representation is used to model the Dictator Game and the Ultimatum Game, which are simple interactions in which it must be decided how a sum of money will be divided between the players in the games. Studies have been conducted into how humans act in such games and the results are not explained by a decision-model that assumes that the participants are purely self-interested utility-maximisers. Some studies further suggest that differences in choices made in different cultures may reflect their day to day behaviour, which can in turn be related to the values of the subjects, and how they order their values. In this paper we show how these interactions can be modelled in agent systems in a framework that makes explicit the reasons for the agents’ choices based upon their social values. Our framework is intended for use in situations where agents are required to be adaptable, for example, where agents may prefer different outcome states in transactions involving different types of counter-parties.     

A Method for Conceptualising Legal Domains. An Example from the Dutch Unemployment Benefits Act

There has been much talk of the need to build intermediate models of the expertise required preparatory to constructing a knowledge-based system in the legal domain. Such models offer advantages for verification, validation, maintenance and reuse. As yet, however, few such models have been reported at a useful level of detail. In this paper we describe a method for conceptualising legal domains as well as its application to a substantial fragment of the Dutch Unemployment Benefits Act (DUBA).We first discuss the intermediate models (called expertise models), then present a three-stage method for their construction, drawing on the CommonKADS work in knowledge acquisition, conceptual models of statute law, and the KANT method of knowledge analysis. Subsequently, we describe how these techniques were applied to the DUBA, and provide detailed examples of the resulting model. Finally, conclusions on the framework and guidelines are given as well as means of recording and presenting the various design choices.     

The World Wide Web as Enabling Technology for CSCW: The Case of BSCW

Despite the growth of interest in the field of CSCW,and the increasingly large number of systems whichhave been developed, it is still the case that fewsystems have been adopted for widespread use. This isparticularly true for widely-dispersed, cross-organisational working groups where problems ofheterogeneity in computing hardware and softwareenvironments inhibit the deployment of CSCWtechnologies. With a lightweight and extensibleclient-server architecture, client implementations forall popular computing platforms, and an existing userbase numbered in millions, the World Wide Web offersgreat potential in solving some of these problems toprovide an enabling technology for CSCWapplications. We illustrate this potential using ourwork with the BSCW shared workspace system – anextension to the Web architecture which provides basicfacilities for collaborative information sharing fromunmodified Web browsers. We conclude that despitelimitations in the range of applications which can bedirectly supported, building on the strengths of theWeb can give significant benefits in easing thedevelopment and deployment of CSCW applications.     

A bistability throughput phenomenon in a shared-memory MIMD machine

This paper examines a previously unanalyzed bistability phenomenon with respect to the number of threads that are doing useful work. This phenomenon is illustrated by a single work queue on a shared-memory machine. An analysis of designs that use two separate memory accesses to lock and unlock critical sections (split transaction) and that employ a first come/first serve queuing mechanism for shared-memory locations is presented. A bistability in the number of threads working, brought about by these conditions, is analyzed and experimentally demonstrated. A simple analysis is presented which predicts the throughput at a critical section of code as a function of the number of applied threads. The study concludes that the mean size of the work items that can be executed in parallel without the possibility of stalling is proportional to the square of the number of threads applied.     

How high growth economies impact global information technology departments

By the very nature of information technology (IT), change and dynamism have always been significant drivers on its path to further development—and it has traditionally been the Western countries leading these. Now the picture is changing. The new high growth economies of the world (also known as BRIC countries) are increasingly pressing forward as active IT development drivers. Internal IT organizations of international companies are experiencing these global shifts firsthand and are facing changes in their traditional roles. This exploratory research is aimed at clarifying the context of the impact of high growth economies on such IT departments of Western-rooted enterprises. Forty-six interviews were conducted with IT managers, HR managers and expatriates emphasizing the importance of intercultural interaction, maturing IT economies, change in IT landscape and entrepreneurship.     

Gaining Confidence in Software Inspection Using a Bayesian Belief Model

In this paper I describe how confidence in a software inspection can be obtained through calculating an estimate of its effectiveness. The method uses a Bayesian Belief Network to model the software inspection process and calculates the inference on how effective a particular inspection was. This technique was selected as it provides a means of initialising the model with inspectors' experience and has the ability to learn and optimise performance. This technique provides answers to some of the questions and limitations raised by current models used to predict inspection effectiveness. The application of the model to a major software project is discussed, covering the initial practitioner survey, model initialisation, model calibration and verification results obtained.     

Assessing the utility of airborne hyperspectral and LiDAR data for species distribution mapping in the coastal Pacific Northwest, Canada

To effectively manage forested ecosystems an accurate characterization of species distribution is required. In this study we assess the utility of hyperspectral Airborne Imaging Spectrometer for Applications (AISA) imagery and small footprint discrete return Light Detection and Ranging (LiDAR) data for mapping 11 tree species in and around the Gulf Islands National Park Reserve, in coastal South-western Canada. Using hyperspectral imagery yielded producer's and user's accuracies for most species ranging from > 52-95.4 and > 63-87.8%, respectively. For species dominated by definable growth stages, pixel-level fusion of hyperspectral imagery with LiDAR-derived height and volumetric canopy profile data increased both producer's (+ 5.1-11.6%) and user's (+ 8.4-18.8%) accuracies. McNemar's tests confirmed that improvements in overall accuracies associated with the inclusion of LiDAR-derived structural information were statistically significant (p < 0.05). This methodology establishes a specific framework for mapping key species with greater detail and accuracy then is possible using conventional approaches (i.e., aerial photograph interpretation), or either technology on its own. Furthermore, in the study area, acquisition and processing costs were lower than a conventional aerial photograph interpretation campaign, making hyperspectral/LiDAR fusion a viable replacement technology.