<p>The theme of this thesis is on transactional support for cooperative work environments, focusing on data sharing. It is thus concerned with the provision of suitable mechanisms to manage concurrent access to shared data and resources. This subject is not new, per se. In fact, maintaining data consistency in multiuser environments is a classical problem that has been addressed thoroughly since the introduction of transaction management. However, while traditional transaction models – also called ACID (atomicity, consistency, isolation, and durability) transactions – have provided satisfactory and efficient consistency management for traditional multiuser database and business applications such as banking and flight reservation applications, they have been found to be too restrictive in the context of cooperation. Atomicity is inappropriate for cooperative environments, where activities are normally of long duration. The isolation of transactions does not allow cooperation, which is thus unsuitable for cooperative environments.</p><p>Several solutions have been proposed and developed in terms of advanced transaction models and frameworks. The goal has primarily been to overcome the limitations of traditional transactions. However, although there are many solutions, there are some problems that are not solved. Among these are the problems that result from the dynamic and heterogeneous nature of cooperative work. Finding solutions to these problems has been a subject for intensive research over the past couple of decades. However, it is widely agreed that they still deserve careful attention. The solution here is to provide transactional support that not only can be tailored to suit different situations, but can also be modified in accordance with changes in the actual environment while the work is being carried out – i.e., is adaptable. As part of this solution, we have identified and extracted the beneficial features from existing models and attempted to extend these to form a transactional framework, called CAGISTrans. This is a framework for the specification of transaction models suiting specific applications. The main contribution in handling dynamic environments is in the way of organising the elements of a transaction model to allow runtime refinement. In addition, a transaction management system has been developed, built on the middleware principle, to allow interoperability and database independence, and support for non-database resources. This thereby addresses the problems induced by the heterogeneous nature of cooperative environments.</p><p>The solution depends on setting requirements based on the practical reallife needs for a system supporting cooperative work. This shows how this framework meets these requirements. One of the issues that is not emphasised is system throughput. From a transaction processing perspective, this issue is generally considered to be critical. However, since transactions in cooperative environments normally span long periods of time, they are mainly more sensitive to response time performance than system throughput. A CAGISTrans system has been implemented, using several technological tools such as Java, XML and software agents. The thesis discusses the specific use of and general experience with these technological tools. The CAGISTrans prototypes have implemented the major parts of the framework. The main conclusion is that the current CAGISTrans framework is able to support the basic features of dynamic and heterogeneous transaction management, allowing users to specify models and have the system execute their transactions in a flexible and controlled manner.</p>

The theme of this thesis is on transactional support for cooperative work environments, focusing on data sharing. It is thus concerned with the provision of suitable mechanisms to manage concurrent access to shared data and resources. This subject is not new, per se. In fact, maintaining data consistency in multiuser environments is a classical problem that has been addressed thoroughly since the introduction of transaction management. However, while traditional transaction models – also called ACID (atomicity, consistency, isolation, and durability) transactions – have provided satisfactory and efficient consistency management for traditional multiuser database and business applications such as banking and flight reservation applications, they have been found to be too restrictive in the context of cooperation. Atomicity is inappropriate for cooperative environments, where activities are normally of long duration. The isolation of transactions does not allow cooperation, which is thus unsuitable for cooperative environments. Several solutions have been proposed and developed in terms of advanced transaction models and frameworks. The goal has primarily been to overcome the limitations of traditional transactions. However, although there are many solutions, there are some problems that are not solved. Among these are the problems that result from the dynamic and heterogeneous nature of cooperative work. Finding solutions to these problems has been a subject for intensive research over the past couple of decades. However, it is widely agreed that they still deserve careful attention. The solution here is to provide transactional support that not only can be tailored to suit different situations, but can also be modified in accordance with changes in the actual environment while the work is being carried out – i.e., is adaptable. As part of this solution, we have identified and extracted the beneficial features from existing models and attempted to extend these to form a transactional framework, called CAGISTrans. This is a framework for the specification of transaction models suiting specific applications. The main contribution in handling dynamic environments is in the way of organising the elements of a transaction model to allow runtime refinement. In addition, a transaction management system has been developed, built on the middleware principle, to allow interoperability and database independence, and support for non-database resources. This thereby addresses the problems induced by the heterogeneous nature of cooperative environments. The solution depends on setting requirements based on the practical reallife needs for a system supporting cooperative work. This shows how this framework meets these requirements. One of the issues that is not emphasised is system throughput. From a transaction processing perspective, this issue is generally considered to be critical. However, since transactions in cooperative environments normally span long periods of time, they are mainly more sensitive to response time performance than system throughput. A CAGISTrans system has been implemented, using several technological tools such as Java, XML and software agents. The thesis discusses the specific use of and general experience with these technological tools. The CAGISTrans prototypes have implemented the major parts of the framework. The main conclusion is that the current CAGISTrans framework is able to support the basic features of dynamic and heterogeneous transaction management, allowing users to specify models and have the system execute their transactions in a flexible and controlled manner.

<p>This work is about supporting user interface design by means of explicit design representations, in particular models.</p><p>We take as a starting point two different development traditions: the formal, analytic, topdown engineering approach and the informal, synthetic, bottom-up designer approach. Both are based on specific design representations tailored to the respective approaches, and are found to have strengths and weaknesses. We conclude that different representations should be used during user interface design, based on their specific qualities and the needs of the design process.</p><p>To better understand the use of design representations a framework for classifying them is developed. A design representation may be classified along three dimensions: the perspective (problem- or solution-oriented) of the representation, the granularity of the objects described and the degree of formality of the representation and its language. Any design approach must provide representation languages that cover the whole classification space to be considered complete. In addition, the transitions between different representations within the representation space must be supported, like moving between task-based and interaction- oriented representations or up and down a hierarchic model. Movements between representations with different degrees of formality are particularly important when combining user-centered design with a model-based approach.</p><p>The design representation classification framework has guided the development of diagrambased modelling languages for the three main perspectives of user interface design, tasks, abstract dialogue and concrete interaction. The framework has also been used for evaluating the languges. A set-based conceptual modelling language is used for domain modelling within all these perspectives. The task modelling language is designed as a hybrid of floworiented process languages and traditional hierarchical sequence-oriented task languages.</p><p>Key features are tight integration with the domain modelling language, expressive and flexible notation and support for classification of task structures. The language for modelling abstract dialogue is based on the interactor abstraction for expressing composition and information flow, and the Statecharts language for activation and sequencing. Parameterized interactors are supported, to provide means of expressing generic and reusable dialogue structures. Modelling of concrete interaction is supported by a combination of the dialogue and domain modelling languages, where the former captures the functionality and behavior and the latter covers concepts that are specific for the chosen interaction style.</p><p>The use of the languages in design is demonstrated in a case study, where models for tasks, dialogue and concrete interaction are developed. The case study shows that the languages support movements along the perspective, granularity and formality dimensions.</p>

<p>This thesis examines how discernibility-based methods can be equipped to posses several qualities that are needed for analyzing tabular medical data, and how these models can be evaluated according to current standard measures used in the health sciences. To this end, tools have been developed that make this possible, and some novel medical applications have been devised in which the tools are put to use.</p><p>Rough set theory provides a framework in which discernibility-based methods can be formulated and interpreted, and also forms an appealing foundation for data mining and knowledge discovery. When the medical domain is targeted, several factors become important. This thesis examines some of these factors, and holds them up to the current state-of-the-art in discernibility-based empirical modelling. Bringing together pertinent techniques, suitable adaptations of relevant theory for model construction and assessment are presented. Rough set classifiers are brought together with ROC analysis, and it is outlined how attribute costs and semantics can enter the modelling process.</p><p>ROSETTA, a comprehensive software system for conducting data analyses within the framework of rough set theory, has been developed. Under the hypothesis that the accessibility of such tools lowers the threshold for abstract ideas to migrate into concrete realization, this aids in reducing a gap between theoreticians and practitioners, and enables existing problems to be more easily attacked. The ROSETTA system boasts a set of flexible and powerful algorithms, and sets these in a user-friendly environment designed to support all phases of the discernibility-based modelling methodology. Researchers world-wide have already put the system to use in a wide variety of domains.</p><p>By and large, discernibility-based data analysis can be varied along two main axes: Which objects in the universe of discourse that we deem it necessary to discern between, and how we define that discernibility among these objects is allowed to take place. Using ROSETTA, this thesis has explored various facets of this also in three novel and distinctly different medical applications:</p><p>*A method is proposed for identifying population subgroups for which expensive tests may be avoided, and experiments with a real-world database on a cardiological prognostic problem suggest that significant savings are possible.</p><p>* A method is proposed for anonymizing medical databases with sensitive contents via cell suppression, thus aiding to preserve patient confidentiality.</p><p>* Very simple rule-based classifiers are employed to diagnose acute appendicitis, and their relative performance is compared to a team of experienced surgeons. The added value of certain biochemical tests is also demonstrated.</p>

<p>To encode, query and present the semantic content of digital video precisely and flexibly is very useful for many kinds of knowledge work: system analysis and evaluation, documentation and education, to name a few. However, that kind of video management is not a trivial matter. The traditional stratified annotation model has quite poor facilities for specifying the meaning – the structure and relationships – of the strata. Because of this, it may also be troublesome to present the annotations to the users in a clear and flexible manner.</p><p>This thesis presents <i>OntoLog</i>, a system for managing the semantic content of video. It extends the stratified annotation model by defining the <i>strata as objects and classes in ontologies</i>, thereby making their semantic meaning more explicit and relating them to each other in a semantic network. The same ontologies are also used to define properties and objects for describing both the strata, individual video intervals and entire videos. This constitutes a very customisable, expressive and precise description model, without sacrificing simplicity and conceptual integrity.</p><p>Arranging the annotation strata in a near-hierarchical network with specified semantics (classes, subclasses and instances) also enables reasoning about the annotations during query and browsing. In particular, it enables <i>visual aggregation of traditional timeline-based strata graphics</i>. Using this to create compact content visualisations, the OntoLog system is able to present tens of videos on screen at the same time, thus providing<i> inter-video browsing</i>. By judiciously disaggregating selected parts of the strata hierarchy, users can focus on relevant strata at their preferred level of detail – <i>overview-and-zoom</i> functionality for semantic annotations, in other words.</p><p>The OntoLog system has been implemented in the form of six Java applications and web services – together covering annotation editing, browsing, analysis, search, query and presentation with various approaches – built on top of an RDF database founded on SQL. The system has been tested under realistic conditions in several real-world projects, with good results. A novel information gathering interface for OntoLog data, Savanta, has been created. This is based on an iterative interaction paradigm featuring inter-video browsing, filtering, navigation and context-sensitive temporal analysis of the annotations. In a comparative usability evaluation, <i>Savanta</i> is shown to outperform more traditional user interfaces for video search/browsing with regard to expressive power, straightforwardness and user satisfaction.</p>

This work is about supporting user interface design by means of explicit design representations, in particular models. We take as a starting point two different development traditions: the formal, analytic, topdown engineering approach and the informal, synthetic, bottom-up designer approach. Both are based on specific design representations tailored to the respective approaches, and are found to have strengths and weaknesses. We conclude that different representations should be used during user interface design, based on their specific qualities and the needs of the design process. To better understand the use of design representations a framework for classifying them is developed. A design representation may be classified along three dimensions: the perspective (problem- or solution-oriented) of the representation, the granularity of the objects described and the degree of formality of the representation and its language. Any design approach must provide representation languages that cover the whole classification space to be considered complete. In addition, the transitions between different representations within the representation space must be supported, like moving between task-based and interaction- oriented representations or up and down a hierarchic model. Movements between representations with different degrees of formality are particularly important when combining user-centered design with a model-based approach. The design representation classification framework has guided the development of diagrambased modelling languages for the three main perspectives of user interface design, tasks, abstract dialogue and concrete interaction. The framework has also been used for evaluating the languges. A set-based conceptual modelling language is used for domain modelling within all these perspectives. The task modelling language is designed as a hybrid of floworiented process languages and traditional hierarchical sequence-oriented task languages. Key features are tight integration with the domain modelling language, expressive and flexible notation and support for classification of task structures. The language for modelling abstract dialogue is based on the interactor abstraction for expressing composition and information flow, and the Statecharts language for activation and sequencing. Parameterized interactors are supported, to provide means of expressing generic and reusable dialogue structures. Modelling of concrete interaction is supported by a combination of the dialogue and domain modelling languages, where the former captures the functionality and behavior and the latter covers concepts that are specific for the chosen interaction style. The use of the languages in design is demonstrated in a case study, where models for tasks, dialogue and concrete interaction are developed. The case study shows that the languages support movements along the perspective, granularity and formality dimensions.

To encode, query and present the semantic content of digital video precisely and flexibly is very useful for many kinds of knowledge work: system analysis and evaluation, documentation and education, to name a few. However, that kind of video management is not a trivial matter. The traditional stratified annotation model has quite poor facilities for specifying the meaning – the structure and relationships – of the strata. Because of this, it may also be troublesome to present the annotations to the users in a clear and flexible manner. This thesis presents OntoLog, a system for managing the semantic content of video. It extends the stratified annotation model by defining the strata as objects and classes in ontologies, thereby making their semantic meaning more explicit and relating them to each other in a semantic network. The same ontologies are also used to define properties and objects for describing both the strata, individual video intervals and entire videos. This constitutes a very customisable, expressive and precise description model, without sacrificing simplicity and conceptual integrity. Arranging the annotation strata in a near-hierarchical network with specified semantics (classes, subclasses and instances) also enables reasoning about the annotations during query and browsing. In particular, it enables visual aggregation of traditional timeline-based strata graphics. Using this to create compact content visualisations, the OntoLog system is able to present tens of videos on screen at the same time, thus providing inter-video browsing. By judiciously disaggregating selected parts of the strata hierarchy, users can focus on relevant strata at their preferred level of detail – overview-and-zoom functionality for semantic annotations, in other words. The OntoLog system has been implemented in the form of six Java applications and web services – together covering annotation editing, browsing, analysis, search, query and presentation with various approaches – built on top of an RDF database founded on SQL. The system has been tested under realistic conditions in several real-world projects, with good results. A novel information gathering interface for OntoLog data, Savanta, has been created. This is based on an iterative interaction paradigm featuring inter-video browsing, filtering, navigation and context-sensitive temporal analysis of the annotations. In a comparative usability evaluation, Savanta is shown to outperform more traditional user interfaces for video search/browsing with regard to expressive power, straightforwardness and user satisfaction.

This thesis examines how discernibility-based methods can be equipped to posses several qualities that are needed for analyzing tabular medical data, and how these models can be evaluated according to current standard measures used in the health sciences. To this end, tools have been developed that make this possible, and some novel medical applications have been devised in which the tools are put to use. Rough set theory provides a framework in which discernibility-based methods can be formulated and interpreted, and also forms an appealing foundation for data mining and knowledge discovery. When the medical domain is targeted, several factors become important. This thesis examines some of these factors, and holds them up to the current state-of-the-art in discernibility-based empirical modelling. Bringing together pertinent techniques, suitable adaptations of relevant theory for model construction and assessment are presented. Rough set classifiers are brought together with ROC analysis, and it is outlined how attribute costs and semantics can enter the modelling process. ROSETTA, a comprehensive software system for conducting data analyses within the framework of rough set theory, has been developed. Under the hypothesis that the accessibility of such tools lowers the threshold for abstract ideas to migrate into concrete realization, this aids in reducing a gap between theoreticians and practitioners, and enables existing problems to be more easily attacked. The ROSETTA system boasts a set of flexible and powerful algorithms, and sets these in a user-friendly environment designed to support all phases of the discernibility-based modelling methodology. Researchers world-wide have already put the system to use in a wide variety of domains. By and large, discernibility-based data analysis can be varied along two main axes: Which objects in the universe of discourse that we deem it necessary to discern between, and how we define that discernibility among these objects is allowed to take place. Using ROSETTA, this thesis has explored various facets of this also in three novel and distinctly different medical applications: *A method is proposed for identifying population subgroups for which expensive tests may be avoided, and experiments with a real-world database on a cardiological prognostic problem suggest that significant savings are possible. * A method is proposed for anonymizing medical databases with sensitive contents via cell suppression, thus aiding to preserve patient confidentiality. * Very simple rule-based classifiers are employed to diagnose acute appendicitis, and their relative performance is compared to a team of experienced surgeons. The added value of certain biochemical tests is also demonstrated.

Paper 2 reprinted with kind permission of IEEE Software. Paper 5 reprinted with kind permission of Springer Verlag.

Paper 2 reprinted with kind permission of IEEE Software. Paper 5 reprinted with kind permission of Springer Verlag.