La complexité comme sagesse, lucidité et liberté : Entrevue avec Jacques Zylberberg, Université Laval, Québec

Dans cet entretien, Jacques Zylberberg s’exprime sur la manière dont le concept de complexité est intervenu dans son oeuvre. Le lecteur apprend que Zylberberg en est venu à la complexité en découvrant qu’elle est davantage savoir fuyant qu’accumulation de données ; qu’elle constitue une façon particulière de décrire le monde ou, mieux, une façon de l’interroger, car le savoir est limité et que la connaissance doit constamment être remise en question, être reconstruite. Associée à l’obligation d’un questionnement continu, la complexité est éthique, position non pas simplement analytique, mais aussi morale, dont les maîtres-mots sont sagesse, lucidité et liberté.In this interview, Jacques Zylberberg expresses himself on the role the concept of complexity has played in his research. The reader finds out that Zylberberg came to complexity in discovering that it is more vanishing knowledge than data accumulation; that it constitutes a particular way for describing the world or, furthermore, a way for questioning it; since knowledge is limited, it must continuously be challenged, reconstructed. Associated with the obligation of a continuous questioning, com-plexity is ethics, a position not only analytical, but moral, whose main terms are wisdom, lucidity, and liberty

Sciences sociales et approche relationnelle

La sociologie, comme l’économie dont elle est issue, et comme la plupart des sciences sociales, oscille entre deux approches : l’une qui veut que les phénomènes sociaux soient interprétables en fonction d’un acteur rationnel, l’autre d’après laquelle l’explication des phénomènes sociaux résulte de la possibilité d’en saisir les relations. Ces deux perspectives cohabitent souvent, même au sein d’une même théorie; mais elles sont contradictoires : le social ne peut être le strict produit d’actions individuelles en même temps que celui des interactions humaines ou des relations entre les phénomènes sociaux. C’est pourquoi l’interactionnisme s’impose aux théories individualistes et pourquoi aussi l’idéologie d’un acteur rationnel, libre, intéressé, intentionnel et stratégique n’annule pas toutes les démarches relationnelles. Les approches relationnelles sont essentielles aux sciences sociales bien simplement parce qu’il n’y a pas d’individu en dehors d’interactions humaines et qu’il n’y a pas non plus de phénomène social qui ne soit pas ou bien un composé de relations ou bien lui-même en relation avec d’autres phénomènes.Sociology, as well as most social sciences, alternates between two approaches: in one case, social phenomena should be understood through a rational actor, in the other, social phenomena is the result of the possibility to understand relations. These two perspectives, although contradictory, often cohabit, even within the same theory; sociality cannot be simultaneously the pure product of individual actions and of human interactions or of relations between social phenomena. This is why interactionism imposes itself upon individualist theories and why the ideology of a rational, free, interested, intentional, and strategic actor does not impend all relational research undertakings. Relational approaches are essential to social sciences simply because there is no individual without human interactions and because there is no social phenomena which is not either a combination of relations or itself in relation with other phenomena

Analyses qualitatives et quantitatives : deux visions, une même science

Cet article suggère que, malgré bon nombre de plaidoiries qui affirment que les méthodes qualitatives et quantitatives sont antinomiques, ces deux types de méthode ont beaucoup en partage et ils sont tous les deux soumis aux mêmes exigences de scientificité. Non seulement jouent-ils des rôles complémentaires dans les sciences humaines, mais, en plus, 1) leurs analyses doivent toujours avoir quelque représentativité, 2) leurs résultats doivent pouvoir caractériser un ensemble étudié, 3) les caractérisations doivent être modulées par les variations individuelles, 4) leurs analyses doivent établir des liens entre les objets/sujets étudiés, et 5) ces analyses sont soumises à la tension qui s’impose entre l’obligation de regrouper les données et celle d’en respecter les particularités.Qualitative and quantitative methods are often presented as opposed or contradictory. The present article suggests that these two types of methods have, in fact, much in common and are bound by the same scientific criteria. Not only are their roles, in human sciences, complementary, but also 1) both their analyses are defined by their representative character, 2) their results must characterize a specific group, 3) their characterizations must be adapted according to individual variations, 4) their analyses must establish links between the studied objects/subjects and 5) their analyses are subject to the necessary tension which stems from the obligation of grouping the results without disregarding the distinctive features of the data

Analyse statistique linéaire et interprétation systémique

La plupart des analyses statistiques sont construites selon une logique linéaire : analyses de variance, analyses de régression. Pourtant, bon nombre de ces analyses dépeignent des phénomènes dont l’interprétation théorique est impossible dans une logique linéaire; ces phénomènes appellent plutôt une théorisation de type dialectique. Plus encore : les techniques statistiques linéaires permettent communément des modélisations multivariées. Or, les associations entre variables qu’elles décrivent, même si elles sont statistiquement soumises à une logique linéaire, permettent aisément des interprétations systémiques. Ainsi, la linéarité de l’analyse statistique peut servir des théorisations relationnelles ou systémiques. C’est ce que voudrait illustrer cet article. Pour ce faire, il présentera les résultats de deux analyses empiriques effectuées avec des outils statistiques sur des phénomènes sociaux (rapport des jeunes à la communauté, usages des médias) et il montrera comment les objets qui sont dépeints ne peuvent être théorisés adéquatement sans qu’on recoure à des notions de récursivité, de dialectique et de système.Most statistical analyses are built according to a linear logic: analysis of variance, regression analysis. Yet, several of these analyses describe phenomena for which theoretical interpretation is impossible with linear logic; these phenomena rather require dialectical type theorization. More than that: linear statistical techniques commonly allow for multivariate modelling. However, associations between the variables that they describe, even though they are statistically submitted to a linear logic, easily allow for a systemic interpretation. Thus, statistical analysis linearity can serve relational or systemic theorizations. That is what the article illustrates. To this end, results from two empirical analyses operated with statistical tools on two social phenomena (relation between youth and their community, media uses) are presented; they show how objects that are depicted cannot be theorized properly without resorting to notions of recursiveness, dialectic, and system

Natural Frequencies Identification of a Reinforced Concrete Beam using Carbon Nanotube Cement-based Sensors.

Cementitious materials doped with carbon nanoparticles are robust materials capable of transducing strain into changes in electrical resistance. These properties encourage the development of spatially distributed sensors for structural health monitoring of concrete structures. Yet, very few applications of transducers made of cement-based nanocomposites to structural elements have been documented. The majority of applications are limited to measurement of static responses

Bio-Based Soft Elastomeric Capacitor for Structural Health Monitoring Applications

Recent advances in flexible electronics have enabled the development of large-area electronics, which are typically fabricated from petroleum-based polymers. With the rapidly growing market of flexible electronics and sensors, there is a pressure to move toward environmentally friendly products. In this article, a bio-based polyurethane soft elastomeric capacitor for structural health monitoring applications is presented. The sensor’s dielectric is fabricated using castor oil–based waterborne polyurethane, mixed with titanium dioxide, which replaces petroleum-based dielectric materials (e.g. styrene-ethylene/butylene-styrene) previously used by the authors. A critical advantage of the proposed castor oil–based polyurethane over styrene-ethylene/butylene-styrene is the environmentally friendly nature of the bio-based polymer and water-based fabrication process of the dielectric that limits the use of solvents. Static characterization demonstrates the linearity of the sensor and its ability to transduce local strain of large surfaces into change in capacitance. Material test results show good physical and chemical properties, despite a decay of the dielectric that occurs after the first 16 days of fabrication

Robust Flexible Capacitive Surface Sensor for Structural Health Monitoring Applications

Early detection of possible defects in civil infrastructure is vital to ensuring timely maintenance and extending structure life expectancy. The authors recently proposed a novel method for structural health monitoring based on soft capacitors. The sensor consisted of an off-the-shelf flexible capacitor that could be easily deployed over large surfaces, the main advantages being cost-effectiveness, easy installation, and allowing simple signal processing. In this paper, a capacitive sensor with tailored mechanical and electrical properties is presented, resulting in greatly improved robustness while retaining measurement sensitivity. The sensor is fabricated from a thermoplastic elastomer mixed with titanium dioxide and sandwiched between conductive composite electrodes. Experimental verifications conducted on wood and concrete specimens demonstrate the improved robustness, as well as the ability of the sensing method to diagnose and locate strain

A novel tuned liquid wall damper for multi-hazard mitigation

A structural system consists of gravity and lateral load resisting components. Structural walls in the gravity system are typically designed to resist vertical loads only, and are assumed to be inactive to mitigate lateral loads. In this paper, we propose a novel multifunctional wall system, which is embedded with multiple-capillaries containing free-flowing fluids and can act as both a load carrying member and a Tuned Liquid Wall Damper (TLWD). Functioning similarly to a Tuned Liquid Column Damper (TLCD), the damping force of the proposed wall system is provided by the head loss of the fluid between each capillary. An analytical model is derived first to describe the dynamic behavior of the TLWD. The accuracy of the analytical model is verified using Computational Fluid Dynamics (CFD) simulations. The model is further used to compute the reduced response of an assumed primary structure attached with a TLWD to demonstrate the damping capability. Results show that TLWDs can effectively dissipate energy while occupying much less space in buildings compared to TLCDs

Performance evaluation of a semi-active cladding connection for multi-hazard mitigation

A novel semi-active damping device termed Variable Friction Cladding Connection (VFCC) has been previously proposed to leverage cladding systems for the mitigation of natural and man-made hazards. The VFCC is a semi-active friction damper that connects cladding elements to the structural system. The friction force is generated by sliding plates and varied using an actuator through a system of adjustable toggles. The dynamics of the device has been previously characterized in a laboratory environment. In this paper, the performance of the VFCC at mitigating non-simultaneous multi-hazard excitations that includes wind and seismic loads is investigated on a simulated benchmark building. Simulations consider the robustness with respect to some uncertainties, including the wear of the friction surfaces and sensor failure. The performance of the VFCC is compared against other connection strategies including traditional stiffness, passive viscous, and passive friction elements. Results show that the VFCC is robust and capable of outperforming passive systems for the mitigation of multiple hazards