Multivariable norm optimal and parameter optimal iterative learning control: a unified formulation

This article investigates the two paradigms of norm optimal iterative learning control (NOILC) and parameter optimal iterative learning control (POILC) for multivariable (MIMO) ?-input, m-output linear discrete-time systems. The main result is a proof that, despite their algebraic and conceptual differences, they can be unified using linear quadratic multi-parameter optimisation techniques. In particular, whilst POILC has been naturally regarded as an approximation to NOILC, it is shown that the NOILC control law can be generated from a suitable choice of control law parameterisation and objective function in a multi-parameter MIMO POILC problem. The form of this equivalence is used to propose a new general approach to the construction of POILC problems for MIMO systems that approximates the solution of a given NOILC problem. An infinite number of such approximations exist. This great diversity is illustrated by the derivation of new convergent algorithms based on time interval and gradient partition that extend previously published work.     

Local and global optima in decision-making: a sheaf-theoretical analysis of the difference between classical and behavioral approaches

One of the main differences between the traditional and the behavioral approaches to decision-making is that the latter has not yet been captured in a unifying framework. This hampers in a certain way the whole research program and raises the question of whether this competing approach can provide an encompassing alternative to the classical one. We analyze this issue in light of the problem of reconstructing global choices of an agent up from the solutions found for local problems. We show that a representation based on category theory of the conditions for such reconstruction is general and robust enough to represent both the case in which problems are non-contextual and local as well as that, typical in the literature on behavioral decision-making, in which such properties do not hold. In the first case, we show how a sheaf-theoretical representation provides an abstract characterization of the global solution. In the latter case, we show how locality and contextuality generate obstructions toward the reconstruction of global solutions, yielding a possible clue for the intrinsic difference between behavioral and classical decision theory.     

Structuration bridging diffusion of innovations and gender relations theories: a case of paradigmatic pluralism in IS research

This paper discusses the adoption of a pluralist theoretical framework – one that is also multiparadigmatic – for conducting and publishing information system (IS) research. The discussion is illustrated by a single case study involving the Australian cotton industry. The theoretical framework is informed by three sociological theories, each with its particular paradigmatic assumptions: structuration theory as a meta‐theory, and diffusion of innovations and gender relations as lower‐level theories from notionally opposing paradigms. Theoretical pluralism helped to produce rich findings, illuminating both the social nature of women farmers' roles, the materiality of the cotton farming context, the characteristics of the decision support systems in use and the recursive way in which human agency and institutional pressures shape each other. Because users of so‐called divergent paradigms often face criticism based on the incommensurability issue, one of the main contributions of this paper is to discuss the value of a pluralist and multiparadigmatic theoretical framework in dealing with complex IS social phenomena.     

Applying relationship theories to web site design: development and validation of a site-communality scale

Our study investigates whether relationship theories can be of help in designing web sites which foster greater customer loyalty. Based on literature reviews of Communal-Relationship Theory from Social Psychology, communality from marketing research and related concepts (e.g. commercial friendships), we develop and refine a multidimensional measure of 'site communality' using a sample of 305 participants. Each visited one among several real web sites chosen across three industries (i.e. banking, pharmaceuticals and insurance). We define site communality as the extent to which web site content signals that a company's relationship with its customers goes beyond the formal, 'tit for tat' business dealings that are typically expected from purely commercial exchanges, and instead, more closely abide by the norms and behaviours evocative of friendships and/or family relations. Our results indicate that demonstration of caring, role spanning and authenticity/genuineness are its most important dimensions. Preliminary, findings also show that site communality is positively related to the benevolence dimension of online trust which is an important antecedent of loyalty. The practical implications of our study are discussed in the form of recommendations to help companies in designing web sites high in site communality.     

Computerization as a means of cultural change: On the relations between information theories and the idea of an information society

Since World War II the concept of Information has received several new definitions. Information can be understood as knowledge in general, as theoretical, formalized knowledge in general or as knowledge related to specific domains or specific representational forms. Because of these mutually inconsistent concepts the common traits are to be found in a perspective transcendent to those theories. The central cultural changes, it is argued, take place on the level of the societal knowledge infrastructure, evolving from the knowledge infrastructure of the industrial societies as a long-term secularization process, resulting in new forms for representation and manipulation of knowledge. The process is seen as rooted in changes of the primary domains for knowledge extraction and in a change in the human relations to the languages in which we interpret the relations to nature.     

A multi-scale approach for modeling fire occurrence probability using satellite data and classification trees: A case study in a mountainous Mediterranean region

Fires constitute one major ecological disturbance which influences the natural cycle of vegetation succession and the structure and function of ecosystems. There is no single natural scale at which ecological phenomena are completely understood and thus the capacity to handle scale is beneficial to methodological frameworks for analyzing and monitoring ecosystems. Although satellite imagery has been widely applied for the assessment of fire related topics, there are few studies that consider fire at several spatial scales simultaneously. This research explores the relationships between fire occurrence and several families of environmental factors at different spatial observation scales by means of classification and regression tree models. Predictors accounting for vegetation status (estimated by spectral indices derived from Landsat imagery), fire history, topography, accessibility and vegetation types were included in the models of fire occurrence probability. We defined four scales of analysis by identifying four meaningful thresholds related to fire sizes in the study site. Sampling methodology was based on random points and the power-law distribution describing the local fire regime. The observation scale drastically affected tree size, and therefore the achieved level of detail, and the most explanatory variables in the trees. As a general trend, trees considering all the variables showed a spectral index ruling the most explicative split. According to the comparison of the four pre-determined analysis scales, we propose the existence of three eventual organization levels: landscape patch or ecosystem level, local level and the basic level, the most heterogeneous and complex scale. Rules with three levels of complexity and applicability for management were defined in the tree models: (i) the repeated critical thresholds (predictor values across which fire characteristics change rapidly), (ii) the meaningful final probability classes and (iii) the trees themselves.