Describing the complexity of systems: multi-variable "set complexity" and the information basis of systems biology

Context dependence is central to the description of complexity. Keying on the pairwise definition of "set complexity" we use an information theory approach to formulate general measures of systems complexity. We examine the properties of multi-variable dependency starting with the concept of interaction information. We then present a new measure for unbiased detection of multi-variable dependency, "differential interaction information." This quantity for two variables reduces to the pairwise "set complexity" previously proposed as a context-dependent measure of information in biological systems. We generalize it here to an arbitrary number of variables. Critical limiting properties of the "differential interaction information" are key to the generalization. This measure extends previous ideas about biological information and provides a more sophisticated basis for study of complexity. The properties of "differential interaction information" also suggest new approaches to data analysis. Given a data set of system measurements differential interaction information can provide a measure of collective dependence, which can be represented in hypergraphs describing complex system interaction patterns. We investigate this kind of analysis using simulated data sets. The conjoining of a generalized set complexity measure, multi-variable dependency analysis, and hypergraphs is our central result. While our focus is on complex biological systems, our results are applicable to any complex system.Comment: 44 pages, 12 figures; made revisions after peer revie

The organisation of sociality: a manifesto for a new science of multi-agent systems

In this paper, we pose and motivate a challenge, namely the need for a new science of multi-agent systems. We propose that this new science should be grounded, theoretically on a richer conception of sociality, and methodologically on the extensive use of computational modelling for real-world applications and social simulations. Here, the steps we set forth towards meeting that challenge are mainly theoretical. In this respect, we provide a new model of multi-agent systems that reflects a fully explicated conception of cognition, both at the individual and the collective level. Finally, the mechanisms and principles underpinning the model will be examined with particular emphasis on the contributions provided by contemporary organisation theory

Justification for inclusion dependency normal form

Functional dependencies (FDs) and inclusion dependencies (INDs) are the most fundamental integrity constraints that arise in practice in relational databases. In this paper, we address the issue of normalization in the presence of FDs and INDs and, in particular, the semantic justification for Inclusion Dependency Normal Form (IDNF), a normal form which combines Boyce-Codd normal form with the restriction on the INDs that they be noncircular and key-based. We motivate and formalize three goals of database design in the presence of FDs and INDs: noninteraction between FDs and INDs, elimination of redundancy and update anomalies, and preservation of entity integrity. We show that, as for FDs, in the presence of INDs being free of redundancy is equivalent to being free of update anomalies. Then, for each of these properties, we derive equivalent syntactic conditions on the database design. Individually, each of these syntactic conditions is weaker than IDNF and the restriction that an FD not be embedded in the righthand side of an IND is common to three of the conditions. However, we also show that, for these three goals of database design to be satisfied simultaneously, IDNF is both a necessary and sufficient condition

Neo-Statecraft Theory, Historical Institutionalism and Institutional Change

This article provides a critical examination of the contribution that statecraft theory, which has been subject to recent revision and development, makes to the literature on institutional change. It articulates an emergent neo-statecraft approach that offers an agent-led form of historical institutionalism. This overcomes the common criticism that historical institutionalists underplay the creative role of actors. The article also argues that the approach brings back into focus the imperatives of electoral politics as a source of institutional change and provides a macro theory of change which is also commonly missing from historical institutionalist work. It can therefore identify previously unnoticed sources of stability and change, especially in states with strong executives and top-down political cultures

Alternative model-building for the study of socially interactive robots

In this discussion paper, we consider the potential merits of applying an alternative approach to model building (Empirical Modelling, also known as EM) in studying social aspects of human-robot interaction (HRI). The first section of the paper considers issues in modelling for HRI. The second introduces EM principles, outlining their potential application to modelling for HRI and its implications. The final section examines the prospects for applying EM to HRI from a practical perspective with reference to a simple case study and to existing models

Individual emergence in contextual analysis

Located within the tradition of Hermeneutic Dialectics (HD) this paper offers an approach which can further an analysis of a fit between information and organizational systems. Drawn upon Information Systems Development projects a relationship between theory and practice is aided through a multi-disciplinary approach to sense making activity. Using a contemporary version of contextual analysis to understand a way in which individuals construct adapt and create meaning from their environment offers a route to improve a systems analysis process. This type of enquiry into contextual dependencies of knowledge creation can help direct a development of systems that have the intention to serve specific organizational actors and their needs. Combining methods outside of a traditional polar divide, sense making research undertaken within a systems thinking arena can enrich understanding by complementing qualitative and / or quantitative analysis with reflective depth. Drawing together interdisciplinary strands through a critical systems thinking approach offers new levels of professionalism for computer- and management-, practitioners or researchers in the 21st Century