Robots have been used in a variety of education, therapy or entertainment contexts. This thesis introduces the novel application of using humanoid robots for Robot-Mediated Interviews (RMIs). In the initial stages of this research it was necessary to first establish as a baseline if children would respond to a robot in an interview setting, therefore the first study compared how children responded to a robot and a human in an interview setting. Following this successful initial investigation, the second study expanded on this research by examining how children would respond to different types and difficulty of questions from a robot compared to a human interviewer. Building on these studies, the third study investigated how a RMI approach would work for children with special needs. Following the positive results from the three studies indicating that a RMI approach may have some potential, three separate user panel sessions were organised with user groups that have expertise in working with children and for whom the system would be potentially useful in their daily work. The panel sessions were designed to gather feedback on the previous studies and outline a set of requirements to make a RMI system feasible for real world users. The feedback and requirements from the user groups were considered and implemented in the system before conducting a final field trial of the system with a potential real world user. The results of the studies in this research reveal that the children generally interacted with KASPAR in a very similar to how they interacted with a human interviewer regardless of question type or difficulty. The feedback gathered from experts working with children suggested that the three most important and desirable features of a RMI system were: reliability, flexibility and ease of use. The feedback from the experts also indicated that a RMI system would most likely be used with children with special needs. The final field trial with 10 children and a potential real world user illustrated that a RMI system could potentially be used effectively outside of a research context, with all of the children in the trial responding to the robot. Feedback from the educational psychologist testing the system would suggest that a RMI approach could have real world implications if the system were developed further.

The embryonic stem cell (ESC) microenvironment contains various localized physical and biochemical cues to direct cell fate. Current approaches for microenvironmental regulation rely on restricting cell behaviour to control endogenous signals such as secreted ligands. This report presents a microfluidic device that can directly manipulate the removal of autoregulatory ligands from culture and control the activation of Signal Transducer and Activator of Transcription-3 (Stat3) in ESCs. Specifically, the response of Stat3 was measured under diffusive and convective mass transfer regimes. A Brownian dynamics algorithm was also developed to simulate ligand transport and predict cellular response under these conditions. Stat3 activation under perfusion culture was found to depend on flow rate and axial distance in the flow direction. Long-term perfusion also allowed for the formation of a sustained gradient of Stat3 activation that led to selective loss of ESC pluripotency. These results demonstrate the utility of microfluidic culture for stem cell bioengineering applications.

The embryonic stem cell (ESC) microenvironment contains various localized physical and biochemical cues to direct cell fate. Current approaches for microenvironmental regulation rely on restricting cell behaviour to control endogenous signals such as secreted ligands. This report presents a microfluidic device that can directly manipulate the removal of autoregulatory ligands from culture and control the activation of Signal Transducer and Activator of Transcription-3 (Stat3) in ESCs. Specifically, the response of Stat3 was measured under diffusive and convective mass transfer regimes. A Brownian dynamics algorithm was also developed to simulate ligand transport and predict cellular response under these conditions. Stat3 activation under perfusion culture was found to depend on flow rate and axial distance in the flow direction. Long-term perfusion also allowed for the formation of a sustained gradient of Stat3 activation that led to selective loss of ESC pluripotency. These results demonstrate the utility of microfluidic culture for stem cell bioengineering applications.

O formalismo matemático da teoria das ondas de spin é analisado. A equivalência entre as transformações de Dyson-Malleev e Holstein-Pr imakoff é demonstrada. Os problemas envolvendo a interação cinemática são discutidos em detalhe. Uma nova divisão do Hamiltoniano de Heisenberg, desenvolvida no espaço de configuração, é usada para estudar a interação dinâmica entre as ondas de spin a baixa temperatura e para grandes valores do número quântico de spin S. Assumindo que a restrição cinemática pode ser neglicenciada, a expansão da energia livre é desenvolvida em potências da temperatura e os resultados estão em acordo com os de Dyson. A relevância da aproximação diagonal de Mattis é demonstrada. Usando o método da positividade por reflexão, limites superiores e inferiores para a contribuição da energia livre são encontrados. Dentro de certa aproximação, estes limites significam que a interação dinâmica pode ser neglicenciada caso o inverso da temperatura (=1/KT), eo número quântico de spin S, forem grandes o suficiente, porém com dependente de S nestas estimativas. Este fato, que não ocorre no limite clássico, é uma característica na região das ondas de spin. / The mathematical formalismo f the spin wave theory is analysed. The thermodynamical equivalence between the Dyson-Malleev and Holstein-Primakoff transformations is proved. The problems involving the kinematical interaction are also discussed in detail. A new splitting of the Heisenberg Hamiltonian, perfomed in configuration space, is used to study the spin wave dynamical interaction at low temperature and for large values of the spin quantum number S. Assuming the the kinematical restriction may be lifted, a low temperature espansion of the free energy is developed with results in agreement with Dysons. The relevance of the Mattis diagonal approximation for the dynamical interaction is demonstrated. Using the method of reflection positivity, upper and lower bounds to the contribuition of the dynamical interaction to the free energy are provided. In a certain approximation, these bounds mean that the dynamical interaction may be dropped IF the inverse temperature (=1/KT) and the spin quantum number S are large enough but depends on S in the estimates, a novel feature wich does not occur in the classical limit but is characteristic of the spin-wave limit.

O formalismo matemático da teoria das ondas de spin é analisado. A equivalência entre as transformações de Dyson-Malleev e Holstein-Pr imakoff é demonstrada. Os problemas envolvendo a interação cinemática são discutidos em detalhe. Uma nova divisão do Hamiltoniano de Heisenberg, desenvolvida no espaço de configuração, é usada para estudar a interação dinâmica entre as ondas de spin a baixa temperatura e para grandes valores do número quântico de spin S. Assumindo que a restrição cinemática pode ser neglicenciada, a expansão da energia livre é desenvolvida em potências da temperatura e os resultados estão em acordo com os de Dyson. A relevância da aproximação diagonal de Mattis é demonstrada. Usando o método da positividade por reflexão, limites superiores e inferiores para a contribuição da energia livre são encontrados. Dentro de certa aproximação, estes limites significam que a interação dinâmica pode ser neglicenciada caso o inverso da temperatura (=1/KT), eo número quântico de spin S, forem grandes o suficiente, porém com dependente de S nestas estimativas. Este fato, que não ocorre no limite clássico, é uma característica na região das ondas de spin. / The mathematical formalismo f the spin wave theory is analysed. The thermodynamical equivalence between the Dyson-Malleev and Holstein-Primakoff transformations is proved. The problems involving the kinematical interaction are also discussed in detail. A new splitting of the Heisenberg Hamiltonian, perfomed in configuration space, is used to study the spin wave dynamical interaction at low temperature and for large values of the spin quantum number S. Assuming the the kinematical restriction may be lifted, a low temperature espansion of the free energy is developed with results in agreement with Dysons. The relevance of the Mattis diagonal approximation for the dynamical interaction is demonstrated. Using the method of reflection positivity, upper and lower bounds to the contribuition of the dynamical interaction to the free energy are provided. In a certain approximation, these bounds mean that the dynamical interaction may be dropped IF the inverse temperature (=1/KT) and the spin quantum number S are large enough but depends on S in the estimates, a novel feature wich does not occur in the classical limit but is characteristic of the spin-wave limit.

Les mécanismes adhésifs jouent un rôle crucial en biologie. Les cadhérines classiques constituent une des principales familles d'adhésion cellulaire dépendante du calcium. Ces glycoprotéines transmembranaires sont impliquées dans des interactions principalement homophiles. Ces interactions régulent des voies de signalisation impliquées dans de nombreux phénomènes biologiques. Cette thèse porte sur l'étude comparative des dynamiques d'interactions des cadhérines E- et -11, prototypes respectivement des cadhérines classiques de type I et II. Le ciblage d'acides aminés particuliers de l'interface adhésive nous a permis de montrer que pour les cadhérines de type I, l'échange de brin avec le Trp2 ont un rôle clé ; pour les types II un mécanisme différent intervient. Nous avons aussi développé une chimie innovante pour contrôler l'immobilisation orientée et covalente de protéines. Enfin une revue décrit une étude de l'activation de voies de signalisation par engagement des cadhérines. / Cell adhesion receptors of the classical cadherin family are involved in Ca2+-dependent homophilic interactions. In order to dissect the molecular mechanisms of cadherin-based cellcell adhesion, this Ph.D. thesis describes a comparative dynamic study of interactions between cadherins E- & -11, chosen as classical type I and II cadherins prototypes respectively. Modifications of particular residues in the E-cadherin adhesive interface showed that the ?-strand exchange with its Trp2 had a prominent feature; for type II cadherins, a different mechanism was described involving a larger domain swapping. We then developed a new protocol for immobilizing proteins in an orientated and covalent manner on surfaces. These interactions regulate signalization pathways in various biological processes. Studies describing Stat3 activation through direct cadherin engagement are reviewed.

No description available.

A crucial limitation of research on strategic planning is that it has always viewed strategic planning as a single process in a corporation. In practice, strategic planning in complex multi-business corporations has evolved into a network of multi-level and multi-unit strategic planning processes. This makes it challenging for managers and strategists to undertake the activities needed to run those strategic planning systems effectively. The interactions between strategy practitioners as they enact those planning processes play a crucial role in determining effectiveness of the planning process as a whole. Therefore, this thesis is based on a conceptual framework that represents strategic planning as a network of collaboration amongst quasi-independent processes taking place across multiple levels and units. This thesis adopts an embedded design within two in-depth case studies and one pilot case study to examine the strategising activities, practices and interaction dynamics of strategic planning within the M-form based firms. The result articulates the dynamics of strategy practitioners’ interactions in a series of four generic interaction patterns: (1) the Bilateral Scheme, (2) the Cohesive Facilitation Scheme, (3) the Ambassadorial Coordination Scheme, and (4) the Supervisory Driven Scheme. The result also sheds light on the extended roles of strategic planning within a multi-level and multi-unit environment, and on how different actors contribute to the vertical and horizontal aspects of strategic planning. The findings of this research have implications for both theory and practice. This thesis mainly contributes to strategy as practice perspective, strategic planning literature, organisational theory, situated learning literature, sensemaking perspective on practice, power theory, and agency theory. Theoretically, this study introduces a new method for examining the practice of strategic planning based on studying strategic planning links between practitioners representing horizontally as well as vertically differentiated units. In doing so, I have represented strategic planning as a multi-unit as well as a multi-level process, and hence have been able to show how it operates as a network of collaborative relationships and activities. This extends the view of strategic planning prevailing in the literature, which portrays a largely hierarchical, vertically-based structure. Practically, the results provide managers and practitioners with an illustration of how different practitioner roles and managerial levels contribute in distinctive ways to strategic planning from both horizontal and vertical perspectives. It is apparent from my investigation of the case study firms that their planning and decentralised decision-making mechanisms are linked together heterarchically as well as hierarchically.

Notre recherche se concentre sur la conception d’interfaces pour la communication émotionnelle à distance. Notre travail s’inscrit notamment dans le cadre de l’élaboration d’espaces numériques d’interactions tactiles, rendus possibles par la connexion en réseau de dispositifs de suppléance perceptive. Nous adoptons une approche énactive et interactionniste de la cognition sociale. Nous utilisons de plus la méthodologie minimaliste, qui offre une opportunité originale d’étudier la constitution des rencontres interpersonnelles au sein d’espaces mettant en place des couplages sensori-Moteurs inédits. Nous déroulons deux méthodologies, en articulant les domaines de la recherche fondamentale, de l’étude expérimentale et du design.Dans un premier temps, nous partons de la théorie autour du thème du toucher, avant de proposer une solution d’interface : l’application smartphone Touch Through. Elle permet une suppléance perceptive du toucher en se basant sur des propriétés fonctionnelles de ce sens. Touch Through sert ensuite à une expérimentation basée autour d’un test de Turing minimaliste, afin de tester la possibilité d’un sentiment de présence à distance avec notre application et de la mettre entre les mains d’utilisateurs.Dans un second temps, nous adressons la question de l’attention conjointe avant de mettre en place une étude expérimentale autour de ce thème (tâche de distinction entre des objets privés et des objets communs). Forts des résultats, nous proposons alors un prototype d’interface pour le réseau social facebook, en mettant en avant des possibilités d’attention conjointe au sein du site et en offrant une interaction inédite autour des posts. / Our research is aimed at designing interfaces for the remote communication of emotions. In particular our work is part of the development of tactile interaction digital spaces. These are made possible by a network connection between perceptual supplementation devices. We consider an enactive and interactionist approach of social cognition. In addition, we use a minimalist methodology. This offers an original opportunity to study the very constitution of interpersonal encounters within spaces where unprecedented sensorimotor couplings happen. We work through two methodologies, each articulating the fields of fundamental research, experimental study and design.In a first phase, we start from theory around the theme of touch, before proposing an interface solution – the smartphone application ‘Touch Through’. This application allows a perceptual supplementation of touch using its functional properties. ‘Touch Through’ is then used in a experimental study based on a minimalist Turing test. This experiment is about testing the possibility of a presence in absence feeling through our application. It was also an opportunity to have users handling it.In the second phase we address the question of joint attention. After a study of this question, we design an experiment where we propose a task of discrimination between private and common objects. Based on the outcome of this experiment, we then propose an interface prototype for the social network ‘facebook’. With this prototype interface, the facebook website is enhanced with possibilities of joint attention. In addition, facebook users can take part in an original interaction around posts.

The analysis of vehicle-structure interaction systems plays a significant role in the design and maintenance of bridges. In recent years, the assessment of the health of existing bridges and the design of new ones has gained significance, in part due to the progress made in the development of faster moving locomotives, the desire for lighter bridges, and the imposition of performance criteria against rare events such as occurrence of earthquakes and fire. A probabilistic analysis would address these issues, and also assist in determination of reliability and in estimating the remaining life of the structure. In this thesis, we aim to develop tools for the probabilistic analysis techniques of state estimation, parameter identification and global response sensitivity analysis of vehicle-structure interaction systems, which are also applicable to the broader class of structural dynamical systems. The thesis is composed of six chapters and three appendices. The contents of these chapters and the appendices are described in brief in the following paragraphs. In chapter 1, we introduce the problem of probabilistic analysis of vehicle-structure interactions. The introduction is organized in three parts, dealing separately with issues of forward problems, inverse problems, and global response sensitivity analysis. We begin with an overview of the modelling and analysis of vehicle-structure interaction systems, including the application of spatial substructuring and mesh partitioning schemes. Following this, we describe Bayesian techniques for state and parameter estimation for the general class of state-space models of dynamical systems, including the application of the Kalman filter and particle filters for state estimation, MCMC sampling based filters for parameter identification, and the extended Kalman filter, the unscented Kalman filter and the ensemble Kalman filter for the problem of combined state and parameter identification. In this context, we present the Rao-Blackwellization method which leads to variance reduction in particle filtering. Finally, we present the techniques of global response sensitivity analysis, including Sobol’s analysis and distance-based measures of sensitivity indices. We provide an outline and a review of literature on each of these topics. In our review of literature, we identify the difficulties encountered when adopting these tools to problems involving vehicle-structure interaction systems, and corresponding to these issues, we identify some open problems for research. These problems are addressed in chapters 2, 3, 4 and 5. In chapter 2, we study the application of finite element modelling, combined with numerical solutions of governing stochastic differential equations, to analyse instrumented nonlinear moving vehicle-structure systems. The focus of the chapter is on achieving computational efficiency by deploying, within a single modeling framework, three sub structuring schemes with different methodological moorings. The schemes considered include spatial substructuring schemes (involving free-interface coupling methods), a spatial mesh partitioning scheme for governing stochastic differential equations (involving the use of a predictor corrector method with implicit integration schemes for linear regions and explicit schemes for local nonlinear regions), and application of the Rao-Blackwellization scheme (which permits the use of Kalman’s filtering for linear substructures and Monte Carlo filters for nonlinear substructures). The main effort in this work is expended on combining these schemes with provisions for interfacing of the substructures by taking into account the relative motion of the vehicle and the supporting structure. The problem is formulated with reference to an archetypal beam and multi-degrees of freedom moving oscillator with spatially localized nonlinear characteristics. The study takes into account imperfections in mathematical modelling, guide way unevenness, and measurement noise. The numerical results demonstrate notable reduction in computational effort achieved on account of introduction of the substructuring schemes. In chapter 3, we address the issue of identification of system parameters of structural systems using dynamical measurement data. When Markov chain Monte Carlo (MCMC) samplers are used in problems of system parameter identification, one would face computational difficulties in dealing with large amount of measurement data and (or) low levels of measurement noise. Such exigencies are likely to occur in problems of parameter identification in dynamical systems when amount of vibratory measurement data and number of parameters to be identified could be large. In such cases, the posterior probability density function of the system parameters tends to have regions of narrow supports and a finite length MCMC chain is unlikely to cover pertinent regions. In this chapter, strategies are proposed based on modification of measurement equations and subsequent corrections, to alleviate this difficulty. This involves artificial enhancement of measurement noise, assimilation of transformed packets of measurements, and a global iteration strategy to improve the choice of prior models. Illustrative examples include a laboratory study on a beam-moving trolley system. In chapter 4, we consider the combined estimation of the system states and parameters of vehicle-structure interaction systems. To this end, we formulate a framework which uses MCMC sampling for parameter estimation and particle filtering for state estimation. In chapters 2 and 3, we described the computational issues faced when adopting these techniques individually. When used together, we come across both sets of issues, and find the complexity of the estimation problem is greatly increased. In this chapter, we address the computational issues by adopting the sub structuring techniques proposed in chapter 2, and the parameter identification method based on modified measurement models presented in chapter 3. The proposed method is illustrated on a computational study on a beam-moving oscillator system with localized nonlinearities, as well as on a laboratory study on a beam-moving trolley system. In chapter 5, we present global response sensitivity indices for structural dynamical systems with random system parameters excited by multiple random excitations. Two new procedures for evaluating global response sensitivity measures with respect to the excitation components are proposed. The first procedure is valid for stationary response of linear systems under stationary random excitations and is based on the notion of Hellinger’s metric of distance between two power spectral density functions. The second procedure is more generally valid and is based on the l2 norm based distance measure between two probability density functions. Specific cases which admit exact solutions are presented and solution procedures based on Monte Carlo simulations for more general class of problems are outlined. The applicability of the proposed procedures to the case of random system parameters is demonstrated using suitable illustrations. Illustrations include studies on a parametrically excited linear system and a nonlinear random vibration problem involving moving oscillator-beam system that considers excitations due to random support motions and guide-way unevenness. In chapter 6 we summarize the contributions made in chapters 2, 3, 4, and 5, and on the basis of these studies, present a few problems for future research. In addition to these chapters, three appendices are included in this thesis. Appendices A and B correspond to chapter 3. In appendix A, we study the effect on the nature of the posterior probability density functions of large measurement data set and small measurement noise. Appendix B illustrates the MCMC sampling based parameter estimation procedure of chapter 3 using a laboratory study on a bending–torsion coupled, geometrically non-linear building frame under earthquake support motion. In appendix C, we present Ito-Taylor time discretization schemes for stochastic delay differential equations found in chapter 5.