Optically-transparent solids have a significant role in many emerging topics of fundamental and applied research, in areas related to Applied Optics and Photonics. In the functional devices based on them, the presence of ‘time-varying temperature fields’ critically limit their achievable performance, when used particularly for high power laser-related tasks such as light-generation, light-amplification, nonlinear-harmonic conversion etc. For optimization of these devices, accurate knowledge of the material thermal parameters is essential. Many optical and non-optical methods are currently in use, for the reliable estimation of the thermal parameters. The thermal diffusivity is a key parameter for dealing with ‘transient heat transport’ related problems. Although its importance in practical design for thermal management is well understood, its physical meaning however continues to be esoteric. The present effort concerns with a few investigations on the “Optical interrogation of ‘transient thermal conduction’ in dielectric solids”. In dielectric solids, the current understanding is that the conductive heat transport occurs only through phonons relevant to microscopic lattice vibrations. Introducing for the first time, a virtual linear translator motion as the basis for heat conduction in dielectric materials, the present investigation discusses an alternative physical mechanism and a new analytical model for the transient heat conduction in dielectric solids. The model brings into limelight a ‘new law of motion’ and a ‘new quantity’ which can be defined at every point in the material, through which time-varying heat flows resulting in time-varying temperature. Physically, this quantity is a measure for the linear translatory motion resulting from transient heat conduction. For step-temperature excitation it bears a simple algebraic relation to the thermal diffusivity of the material. This relationship helps to define the thermal diffusivity of a dielectric solid as the “translatory motion speed” measured at unit distance from the heat source. A novel two-beam interferometric technique is proposed and corroborated the proposed concept with significant advantages. Two new approaches are introduced to estimate thermal diffusivity of optically transparent dielectric solid; first of them involves measurement of the position dependent velocity of isothermal surface and second one depend on the measurement of position dependent instantaneous velocity of normalized moving intensity points. A ‘new mechanism’ is proposed and demonstrated to visualize, monitor and interrogate optically, the ‘linear translatory motion’ resulting from the transient heat flow due to step- temperature excitation. Two new approaches are introduced, first one is ‘mark’ and ‘track’ approach, it involves a new interaction between sample supporting unsteady heat flow with its ambient and produces optical mark. Thermal diffusivity is estimated by tracking the optical mark. Second one involves measurement of instantaneous velocity of optical mark for different step-temperature at a fixed location to estimate thermal diffusivity. A new inverse method is proposed to estimate thermal diffusivity and thermal conductivity from the volumetric specific heat capacity alone through thought experiment. A new method is proposed to predict volumetric specific heat capacity more accurately from thermal diffusivity.

Network Direct Selling Organisations (NDSOs) exist in more than 50 countries and have more than 74 million members. The most recent statistical information reveals that the vast majority of members do not earn significant income. Criticism of these organisations revolves around the ethicality of consumption, the commercialisation of personal relationships, and the exploitation of unrealistic expectations. This study aims to explore how communication creates networks that sustain an industry of this kind despite the improbability of its existence. The study commences with a description of NDSOs from historical, operational, tactical, and strategic perspectives. Given the broader context created by the global presence of this industry, cybernetics has been selected as a meta-theoretical perspective for the study of communication. The more recent development of second-order cybernetics and social autopoiesis are introduced to communication theory as a field. Niklas Luhmann‟s new social theory of communication is assessed and applied in relation to existing communication theory. New conceptual models are developed to explore communication as the unity of the synthesis of information, utterance, understanding, and expectations as selections that occur both consciously and unconsciously, intentionally and unintentionally. These models indicate the multiplexity of individual and social operationally closed, yet informationally open systems, and they are used here to provide a systemic and coherent alternative to orthodox communication approaches to the study of organisations. The study adopts a constructivist epistemological stance and propounds throughout the necessity of further interdisciplinary collaboration. The study concludes that individuals are composite unities of self-creating systems, and they co-create social systems by self-creating and co-creating meaning. Meaning is described as the continuous virtualisation and actualisation of potentialities that in turn coordinate individual and social systems‟ actions. A communication process flow model is created to provide a theoretical explanation for the existence of NDSOs as self-creating systems. The study aims to show that communication has arguably become the most pervasive discipline as a result of the globally interactive era. It is shown that second-order cybernetics and social autopoiesis raise several further questions to be explored within communication theory as a field. / Communication, first-order cybernetics, second-order cybernetics, Complexity and complex systems, autopoiesis, self-reference, recursivity, operational closure, system boundaries, Network Direct Selling Organisations / Communication / D. Litt. et Phil. (Communication)

We study the properties of a number of algorithms proposed to explore the computational space generated by a very simple and general idea: the notion of a mathematical definition and a number of suggested formal interpretations ofthis idea. Theories of partial inductive definitions (PID) constitute a class of logics based on the notion of an inductive definition. Formal systems based on this notion can be used to generalize Horn-logic and naturally allow and suggest extensions which differ in interesting ways from generalizations based on first order predicate calculus. E.g. the notion of completion generated by a calculus of PID and the resulting notion of negation is completely natural and does not require externally motivated procedures such as "negation as failure". For this reason, computational issues arising in these calculi deserve closer inspection. This work discuss a number of finitary theories of PID and analyzethe algorithmic and semantical issues that arise in each of them. There has been significant work on implementing logic programming languages in this setting and we briefly present the programming language and knowledge modelling tool GCLA II in which many of the computational prob-lems discussed arise naturally in practice. / <p>Also published as SICS Dissertation no. SICS-D-19</p>

Cette thèse étudie les représentations du passé par les marques et leur effet sur les consommateurs dans le cadre théorique de la distance temporelle. Que se passe-t-il lorsqu’une marque indique sa date de fondation sur un packaging, présente son histoire en page d’accueil du site internet ou fait de son fondateur le personnage central de ses créations publicitaires ? L’objectif de cette thèse est de qualifier ce phénomène, de mieux le comprendre et d’en mesurer les effets cognitifs et affectifs sur les consommateurs. La première partie de la thèse situe ce phénomène par rapport aux recherches sur le rôle du temps en marketing, et plus particulièrement à celles liées au passé comme le marketing rétrospectif, la nostalgie, l’authenticité et la consommation du passé. La seconde partie présente deux études qualitatives et cinq études quantitatives (chapitres 4 à 6) dont les résultats permettent de 1) proposer une nouvelle échelle pour mesurer la perception du patrimoine de marque, 2) démontrer que la mobilisation du patrimoine de marque augmente la distance temporelle entre le consommateur et la marque, 3) montrer que le patrimoine de marque est associé à des bénéfices cognitifs même si la causalité n’est pas vérifiée, et 4) prouver que le patrimoine de marque a un effet sur l’attachement à la marque, uniquement si les consommateurs en sont familiers. Ces résultats contribuent à la recherche sur la gestion de la temporalité de la marque, aux travaux sur le concept de patrimoine de marque, sur les effets cognitifs et affectifs des représentations du passé par les marques, et sur les effets de la distance temporelle dans le passé / This doctoral thesis explores brands’ representations of the past and their effect on consumers in the theoretical framework of temporal distance. What happens when a brand indicates its founding date on a packaging ? Or puts forward its history on its website ? Or uses its founder as the central character in an advertising campaign ? This thesis aims to qualify this phenomenon, to better understand it, and to measure its cognitive and affective effects on consumers. The first part of the dissertation situates this phenomenon with regards to existing research on the role of time in marketing, and most particularly, to the research relating to the past such as retrospective branding, nostalgia, authenticity and the commodification of the past. The second part details two qualitative and five quantitative empirical studies whose results : 1) suggested a new scale to measure the perception of brand heritage, 2) demonstrated that brand heritage increases temporal distance between the brand and its consumers, 3) showed that brand heritage is associated with cognitive benefits although causality is not assessed, and 4) proved the effect of brand heritage on brand attachment for familiar brands. Those results contribute to the research on temporality in brand management, on the concept of brand heritage and its measurement, on the cognitive and affective consequences of brands’ representations of the past, and on the temporal distance on the past