From Models to Simulations

This book analyses the impact computerization has had on contemporary science and explains the origins, technical nature and epistemological consequences of the current decisive interplay between technology and science: an intertwining of formalism, computation, data acquisition, data and visualization and how these factors have led to the spread of simulation models since the 1950s. Using historical, comparative and interpretative case studies from a range of disciplines, with a particular emphasis on the case of plant studies, the author shows how and why computers, data treatment devices and programming languages have occasioned a gradual but irresistible and massive shift from mathematical models to computer simulations

Agent-Based Models and Simulations in Economics and Social Sciences: from conceptual exploration to distinct ways of experimenting

Now that complex Agent-Based Models and computer simulations spread over economics and social sciences - as in most sciences of complex systems -, epistemological puzzles (re)emerge. We introduce new epistemological tools so as to show to what precise extent each author is right when he focuses on some empirical, instrumental or conceptual significance of his model or simulation. By distinguishing between models and simulations, between types of models, between types of computer simulations and between types of empiricity, section 2 gives conceptual tools to explain the rationale of the diverse epistemological positions presented in section 1. Finally, we claim that a careful attention to the real multiplicity of denotational powers of symbols at stake and then to the implicit routes of references operated by models and computer simulations is necessary to determine, in each case, the proper epistemic status and credibility of a given model and/or simulation

Agent-Based Models and Simulations in Economics and Social Sciences

Now that complex Agent-Based Models and computer simulations spread over economics and social sciences - as in most sciences of complex systems -, epistemological puzzles (re)emerge. We introduce new epistemological concepts so as to show to what extent authors are right when they focus on some empirical, instrumental or conceptual significance of their model or simulation. By distinguishing between models and simulations, between types of models, between types of computer simulations and between types of empiricity obtained through a simulation, section 2 gives the possibility to understand more precisely - and then to justify - the diversity of the epistemological positions presented in section 1. Our final claim is that careful attention to the multiplicity of the denotational powers of symbols at stake in complex models and computer simulations is necessary to determine, in each case, their proper epistemic status and credibility.Agent-Based Models and Simulations ; Epistemology ; Economics ; Social Sciences ; Conceptual Exploration ; Model World ; Credible World ; Experiment ; Denotational Hierarchy

On the Risk of Life Insurance Liabilities: Debunking Some Common Pitfalls

The objective of this paper is to contribute to a better understanding of the driving forces of a life insurance company. More specifically, the issues of the duration and convexity of insurance liabilities and equity are addressed. These issues deserve a careful rethinking given the recent trends that have affected the insurance landscape. A correct assessment of these risk measures is critical as they constitute the primary ingredients of any sound asset-liability management approach. In addition, the effort toward a more detailed and more accurate risk picture of life insurance operations enables one to debunk some pitfalls that are commonly encountered in the insurance industry. This paper was presented at the Financial Institutions Center's May 1996 conference on "

The Nature of Computational Things

Architecture often relies on mathematical models, if only to anticipate the physical behavior of structures. Accordingly, mathematical modeling serves to find an optimal form given certain constraints, constraints themselves translated into a language which must be homogeneous to that of the model in order for resolution to be possible. Traditional modeling tied to design and architecture thus appears linked to a topdown vision of creation, of the modernist, voluntarist and uniformly normative type, because usually (mono)functionalist. One available instrument of calculation/representation/prescription orders this conception of architecture: indeed the search for an optimal solution through mathematical calculation of a model itself mathematical, thus homogeneous and simple, is only possible when one or two functions or functional constraints are formulated, never more, and this, on a global level, therefore starting from a unique and homogenizing viewpoint. It is essential to grasp that, even applied to material and its properties or towards a particular esthetic or functional dimension, this viewpoint is thus abstractive and generalizing: disregarding singularity of context, insertion and relationship to the environment or local, social behavior. It leaves aside functional specificity and heterogeneousness – re-contextualized each time – of functions that the object or edifice are required to fulfill and optimize under diverse constraints, in their different parts. The computational turning point today’s digital design and computational architecture embody modifies these instrumental, original prescriptions, rendering them more flexible. Perhaps in light of this turnabout we should retrospectively interpret 20th century calls for modernism, functionalism and even biomorphism as being just as many ex post rationalizations in respect to techniques of strongly prescriptive modeling since our only instrument is a monolithic language, and so being, incites a top-down conception, (naturally weakly reactive to contexts), including forms whose overall appearance resembles in fine a living form. In order to liberate oneself from this and despite everything, emerge as its initiators, one has constructed from ideology and philosophy (of object, habitat, the urban) ex post, even while it is the instrument of modeling and conception that largely determines, normalizes and dictates ex ante, the possibilities and limitations of the creation of forms and living experiments4 in a given time

Imagining How to Break the Co-optation of a Consensus. A Response to “Imagining No Child Left Behind Freed from Neoliberal Hijackers”

Given that I share, mostly, Eugene Matusov’s passionate concerns, picking on his vocabulary might appear pedantic. However, the issues involved in labeling political movements and, even more, political practices, can be fundamental and address the very grounds on which social analysis must stand. Briefly, I am concerned with the label neo-liberal, particularly when it is used as an epithet and blinds us to actual processes. I end with some, perhaps optimistic, remarks about the rise of educational activities that are not already marked for measurement on any pass/fail scale

La brièveté des inscriptions médiévales: d’une contrainte à une esthétique

Les inscripcions són conegudes per la seva brevetat, fins al punt que aquesta característica participa en la definició del discurs epigràfic. Malgrat això, els mitjans lingüístics i gràfics els quals permeten als textos ser curts, no han estat estudiats. Es tracta doncs d'entendre com i per què aquests textos són breus, més enllà de la restricció material fins a crear una veritable estètica. Seleccionar les informacions, condensar la proposició gràcies a recursos retòrics, el ritme de la paraula, evocar i suggerir les idees més que de desenvolupar-les, tals són els verbs que guien els autors d'inscripcions. La brevetat epigràfica no és pas una conseqüència del suport, de la matèria, de l'espai o inclús del cost. Ella permet per altra banda a la inscripció d'exercir millor la seva funció de comunicació i de publicitat universal i durable. Aquesta recerca de concisió s'explica tant sobre un plà lingüístic com a nivell gràfic. Aquesta doble recerca confereix aleshores a l'escriptura epigràfica - entesa en sentit ampli - una veritable estètica.Inscriptions are known for their brevity and this characteristic participates in the definition of the epigraphic discourse. Nevertheless, the linguistic and graphic means which allow these texts to be short have not been studied. Our goal is thus to understand how and why these texts are brief, beyond the material constraint, until create a real esthetics. Select the information, condense the words thanks to rhetorical processes, give rhythm to the speech, evoke and suggest the ideas rather than to develop them, such are the verbs which guide the authors of inscriptions. The epigraphic brevity is not only a consequence of the support, the material, the space or still the cost. On the contrary, it allows inscriptions to exercise at best their function of communication and universal and long-lasting advertisement. This research for conciseness is visible both on a linguistic and graphic plan. It confers then on the epigraphic writing —in the broad sense— a specific esthetics.Les inscriptions sont connues pour leur brièveté, à tel point que cette caractéristique participe à la définition du discours épigraphique. Néanmoins, les moyens linguistiques et graphiques qui permettent à ces textes d’être courts n’ont pas été étudiés. Il s’agit donc de comprendre comment et pourquoi ces textes sont brefs, au-delà de la contrainte matérielle, jusqu’à créer une véritable esthétique. Sélectionner les informations, condenser le propos grâce à des procédés rhétoriques, rythmer le discours, évoquer et suggérer les idées plutôt que de les développer, tels sont les verbes qui guident les auteurs d’inscriptions. La brièveté épigraphique n’est pas qu’une conséquence du support, de la matière, de l’espace ou encore ducoût. Elle permet au contraire à l’inscription d’exercer au mieux sa fonction de communication et de publicité universelle et durable. Cette recherche de concision s’exprime tant sur un plan linguistique qu’au niveau graphique. Cette double recherche confère alors à l’écriture épigraphique —entendue au sens large— une vraie esthétique

Interprétabilité et explicabilité pour l’apprentissage machine : entre modèles descriptifs, modèles prédictifs et modèles causaux. Une nécessaire clarification épistémologique

Le déficit d’explicabilité des techniques d’apprentissage machine (AM) pose des problèmes opérationnels, juridiques et éthiques. Un des principaux objectifs de notre projet est de fournir des explications éthiques des sorties générées par une application fondée sur de l’AM, considérée comme une boîte noire. La première étape de ce projet, présentée dans cet article, consiste à montrer que la validation de ces boîtes noires diffère épistémologiquement de celle mise en place dans le cadre d’une modélisation mathématique et causale d’un phénomène physique. La différence majeure est qu’une méthode d’AM ne prétend pas représenter une causalité entre les paramètres d’entrées, qui peuvent être de plus de haute dimensionnalité, et ceux de sortie. Nous montrons dans cet article l’intérêt de mettre en œuvre les distinctions épistémologiques entre les différentes fonctions épistémiques d’un modèle, d’une part, et entre la fonction épistémique et l’usage d’un modèle, d’autre part. Enfin, la dernière partie de cet article présente nos travaux en cours sur l’évaluation d’une explication, qui peut être plus persuasive qu’informative, ce qui peut ainsi causer des problèmes d’ordre éthique

Coaching the Wii : evaluation of a physical training experiment assisted by a video game

Aging or sedentary behavior can decrease motor capabilities causing a loss of autonomy. Prevention or readaptation programs that involve practice of physical activities can be precious tools to fight against this phenomenon. ?Serious? video game have the potential to help people to train their body mainly due to the immersion of the participant in a motivating interaction with virtual environments. We propose here to discuss the results of a preliminary study that evaluated a training program using the well-known WiiFit game and Wii balance board device in participants of different ages. Our results showed that participants were satisfied with the program and that they progressed in their level of performance. The most important observation of this study, however was that the presence of a real human coach is necessary in particular for senior participants, for security reasons but also to help them to deal with difficulties with immersive situations.Comment: 4 page