L'important,C'est Les Lunettes

Applying mathematics to solve any problem inevitably grants an aura of objectivity and truth to the results generated through such methodology. However, mathematics remains a means of elucidation that functions within strict constraints of tractability and stylization. Despite the aesthetics of models and the precision of computation, mathematical representations are but a shadow of the reality they seek to characterize. Nonetheless, because mathematics' pure form hides its own limitations, it becomes a privileged site of scholastic reason and, at the same time, of symbolic violence, two notions that Bourdieu theorized in his work. Despite this handicap, Bourdieu recognized the importance of formalizing tools such as those derived from mathematics. He thus devised many strategies to take advantage of their power of elucidation while avoiding the distortions and dogmatic stance they unavoidably bring about. This paper examines these strategies in detail to further inspire the identification of a number of reflexive approaches that can deflect the potential symbolic violence of mathematical reasoning. In this analysis, particular attention is given to the specific needs of practitioners engaged in mathematical formulation such as economists, statisticians, operations researchers and other quantitative scientists. This process of reflexive discovery is then used to enrich the notion of ‘specific intellectual’ that Foucault introduced and that Bourdieu further specified and ‘lived’. The paper concludes by foregrounding the perhaps unexpected moral dimensions of applied mathematics, a discipline that otherwise often appear distant and esoteric.     

Mutual Aid: A Contribution to Best-Practice Social Work

This keynote speech, delivered in French and translated to English with minor adjustments for publication, presents some of the author's ideas about mutual-aid practice as best-practice social work. The author discusses the etiology and centrality of mutual aid in social work with groups, presents five characteristics of mutual-aid practice that reflect best-practice social work and identifies four key characteristics—joy in sharing, faith, courage, and curiosity—of mutual-aid practitioners. Similarities between mutual-aid practice and evidence-based group work, practice evaluation and participatory-action research are discussed as well. The author presents group work as inherently evidence based and challenges the idea that subjective measures alone may not be valid in reaching this determination.     

Multiple criteria decision analysis of treatment and land-filling technologies for waste incineration residues

In this paper, we present a real-world case realized in Switzerland on behalf of the federal agency in charge of the waste policy. The incineration of urban wastes generates hazardous residues that need specific treatment and/or land-filling technologies. The variety of local situations and appraisals led to the choice of very different solutions. Moreover, proponents were keen to propose new technologies. The purpose of this study was to provide the background for a national policy that would apply to all future projects.     

Estimation of k-Factor GIGARCH Process: A Monte Carlo Study

In this article, we discuss the parameter estimation for a k-factor generalized long-memory process with conditionally heteroskedastic noise. Two estimation methods are proposed. The first method is based on the conditional distribution of the process and the second is obtained as an extension of Whittle's estimation approach. For comparison purposes, Monte Carlo simulations are used to evaluate the finite sample performance of these estimation techniques, using four different conditional distribution functions.     

Computer experiments: a review

In this paper we provide a broad introduction to the topic of computer experiments. We begin by briefly presenting a number of applications with different types of output or different goals. We then review modelling strategies, including the popular Gaussian process approach, as well as variations and modifications. Other strategies that are reviewed are based on polynomial regression, non-parametric regression and smoothing spline ANOVA. The issue of multi-level models, which combine simulators of different resolution in the same experiment, is also addressed. Special attention is given to modelling techniques that are suitable for functional data. To conclude the modelling section, we discuss calibration, validation and verification. We then review design strategies including Latin hypercube designs and space-filling designs and their adaptation to computer experiments. We comment on a number of special issues, such as designs for multi-level simulators, nested factors and determination of experiment size.     

ON FINDING AN INITIAL SOLUTION FOR THE DUAL SIMPLEX ALGORITHM

Torrance [4] has proposed a “new” approach to finding an initial solution of a linear programming problem for use in conjunction with the dual simplex algorithm. The purpose of this note is to comment on two aspects of that paper. Firstly, Torrance's method is not new at all, but was proposed in 1958 by Wagner. Secondly, the method can be implemented much more efficiently than Torrance suggests.     

Online epistemic communities: theoretical and methodological directions for understanding knowledge co-elaboration in new digital spaces

This paper presents, illustrates and discusses a generic framework for studying knowledge co-elaboration in online epistemic communities ("OECs"). Our approach is characterised by: considering knowledge co-elaboration as a design activity; distinguishing discussion and production spaces in OECs; characterising participation via the notion of role; fine-grained analyses of meaning, content and communicative functions in interactions. On this basis, three key issues for ergonomics research on OECs are discussed and illustrated by results from our previous studies on OSS and Wikipedia. One issue concerns the interrelation between design (task) and regulation. Whereas design task-oriented activity is distributed among participants, we illustrate that OCEs function with specialised emerging roles of group regulation. However, the task-oriented activity also functions at an interpersonal level, as an interplay of knowledge-based discussion with negotiation of competencies. Another issue concerns the foci of activity on the (designed) knowledge object. Based on a generic task model, we illustrate asymmetry and distinctiveness in tasks' foci of participants. The last issue concerns how design-use mediation is ensured by specific forms of mediation roles in OECs. Finally we discuss the degree of generality of our framework and draw some perspectives for extending our framework to other OECs.     

‘The whole is always smaller than its parts’ – a digital test of Gabriel Tardes' monads

In this paper we argue that the new availability of digital data sets allows one to revisit Gabriel Tarde's (1843–1904) social theory that entirely dispensed with using notions such as individual or society. Our argument is that when it was impossible, cumbersome or simply slow to assemble and to navigate through the masses of information on particular items, it made sense to treat data about social connections by defining two levels: one for the element, the other for the aggregates. But once we have the experience of following individuals through their connections (which is often the case with profiles) it might be more rewarding to begin navigating datasets without making the distinction between the level of individual component and that of aggregated structure. It becomes possible to give some credibility to Tarde's strange notion of ‘monads’. We claim that it is just this sort of navigational practice that is now made possible by digitally available databases and that such a practice could modify social theory if we could visualize this new type of exploration in a coherent way.