Financial Markets imperfections, heterogeneity and growth

This paper offers a model of growth with heterogeneous agents in which, due to asymmetric information, financial markets do not work properly. In such a world, the Modigliani-Miller theorem fails to hold, a financial hierarchy emerges and ‘how to finance’ the engine of growth – in our case represented by uncertain endeavours in R&D - matters. In turn, heterogeneity means that agents lack sufficient information on the behaviour adopted by the others, forcing them to make use of naive rules in forming expectations and in calculating their probability of bankruptcy. The basic properties of the model are explored via simulations. In particular, it is possible to appreciate how a worsening of financial conditions (e.g. an increase of the contractual interest rate on loans or of the probability of bankruptcy) affects negatively the long-run average rate of growth

Evaluation de la capacité adaptative des socio-écosystèmes forestiers français face au changement climatique : le cas de la migration assistée

In a climate change context, the implementation of adaptive strategies appears as one of the greatest challenges for our societies. At the beginning of the 21st century, the scientific community proposed an adaptation option to limit climate change impacts on biodiversity, the assisted migration (AM). Despite a good theoretical justification, the AM application raises several questions about ecological, economical, ethical and political issues. Along this thesis, I was interested in the adaptive capacity of society actors concerning the changing climate, through the implementation of new practices as AM. Given the slow migration capacity of tree species, forests represent a relevant ecosystem for AM application, especially in France which has more than 29% of its surface as forest areas that are highly fragmented. In the first part of this thesis, I concentrated on the AM debate and I analyzed the actual barriers in its conception and its implementation. On the basis of a comparative analysis between France and Canada, I highlighted that different acceptations of adaptation and AM between policy and scientific actors represent a barrier for the implementation of adaptive strategies, as AM. Hence, I proposed a new concept of AM at the ecosystem scale, allowing limiting the focus on economic issues of AM programs. Moreover, I demonstrated that the AM actions are not constrained in a precautionary approach but could be applied in a prevention context. These results unties the deadlock about the “when to act?” question. After an empirical and theoretical analysis of AM and its context, in the second part of this thesis, I was interested on the real application of AM in the field. Therefore, I evaluated the capacity of forest actors to change their practices in a climate change context, with an original method based on the estimation of local capitals. Sadly, this analysis showed that for the moment, foresters implement more easily strategies for increasing robustness than resilient or transformative strategies, increasing the fragility of socio-ecosystems and risking a violent collapse of them.Dans la problématique du changement climatique, la mise en place de nouvelles stratégies d’adaptation apparaît comme un des grands challenges de nos sociétés actuelles. C’est au début des années 2000, que la communauté scientifique a proposé une option de gestion de la biodiversité afin de limiter les impacts dus à la vitesse du changement climatique, cette option étant connue sous le nom de migration assistée (MA). Cependant, malgré une justification théorique intéressante, l’application de cette pratique a soulevé de nombreuses questions autant éthiques, écologiques, économiques que politiques. Tout au long de cette thèse, je me suis intéressée à la capacité d’adaptation des acteurs face au changement climatique, via la mise en place de nouvelles pratiques de gestion, en s’intéressant tout particulièrement au cas de la MA. Compte tenu du rythme de migration lent des espèces forestières, les forêts représentent un écosystème pertinent pour la mise en place de la MA, et plus spécifiquement pour la France, qui compte plus de 29% de son territoire en surface boisée avec une forte problématique de fragmentation. Dans la première partie de cette thèse, nous nous sommes intéressés au débat que la MA a suscité et j’ai analysé les blocages qui existent actuellement dans sa conception et sa mise en place. Sur la base d’une analyse comparative entre la France et le Canada, j’ai pu mettre en évidence que les différentes conceptions d’adaptation et de MA entre les acteurs politiques et les scientifiques représentaient des barrières à l’application de programmes de MA. Ainsi, j’ai proposé une nouvelle conception de la MA, avec un volet écosystémique, permettant de limiter les approches économico-centrée de ces programmes. De plus, j’ai démontré que l’action de MA ne s’inscrit pas seulement dans une démarche de précaution mais également de prévention, dénouant ainsi le blocage présent sur la question du « quand doit-on agir ? ». Après une analyse théorique et empirique de la MA et de son contexte, dans la seconde partie, nous nous sommes posés la question de sa réelle application sur le terrain. J’ai donc analysé la capacité des acteurs forestiers locaux à mettre en œuvre des stratégies d’adaptation grâce à une méthode originale d’estimation des capitaux locaux. Malheureusement, cette analyse a montré qu’à l’heure actuelle, les forestiers mettent plus facilement en place des stratégies favorisant la robustesse que des stratégies plus complexes de résilience globale ou de transformabilité, telle que la MA, augmentant ainsi la fragilisation des socio-écosystèmes et risquant des transitions brutales

Cutting the Climate-Development Gordian Knot - Economic options in a politically constrained world

Combating climate change cannot but be a cooperative venture amongst nations. Together with the problem posed by the withdrawal of the US from the Kyoto Protocol, the key challenge for winning the battle is the involvement of developing countries in efforts to alter their GHGs emissions trends. This involvement is necessary technically but also politically to bring the largest emitter of the planet back on the battle field. In the first section we draw on history to outline the intellectual underpinning of North/South divide around climate affairs. In the second section we show the economic basis for a leverage effect between development and climate policies. The third section ventures to propose some guidance to develop a viable climate regime strong enough to support an ambitious effort to decarbonize economies and we show that the Kyoto framework, once re-interpreted and amended is not so far from this working drawing.climate policy; development

Biometric Systems

Biometric authentication has been widely used for access control and security systems over the past few years. The purpose of this book is to provide the readers with life cycle of different biometric authentication systems from their design and development to qualification and final application. The major systems discussed in this book include fingerprint identification, face recognition, iris segmentation and classification, signature verification and other miscellaneous systems which describe management policies of biometrics, reliability measures, pressure based typing and signature verification, bio-chemical systems and behavioral characteristics. In summary, this book provides the students and the researchers with different approaches to develop biometric authentication systems and at the same time includes state-of-the-art approaches in their design and development. The approaches have been thoroughly tested on standard databases and in real world applications

Power, land and Ethnicity in the Kassala-Gedaref States

The papers presents the situation of the Kassala-Gedaref States and analyzes their political, economical and ethnic composition. It raises the need for areal studies in the Suda

Transport Layer solution for bulk data transfers over Heterogeneous Long Fat Networks in Next Generation Networks

Aquesta tesi per compendi centra les seves contribucions en l'aprenentatge i innovació de les Xarxes de Nova Generació. És per això que es proposen diferents contribucions en diferents àmbits (Smart Cities, Smart Grids, Smart Campus, Smart Learning, Mitjana, eHealth, Indústria 4.0 entre d'altres) mitjançant l'aplicació i combinació de diferents disciplines (Internet of Things, Building Information Modeling, Cloud Storage, Ciberseguretat, Big Data, Internet de el Futur, Transformació Digital). Concretament, es detalla el monitoratge sostenible del confort a l'Smart Campus, la que potser es la meva aportació més representativa dins de la conceptualització de Xarxes de Nova Generació. Dins d'aquest innovador concepte de monitorització s'integren diferents disciplines, per poder oferir informació sobre el nivell de confort de les persones. Aquesta investigació demostra el llarg recorregut que hi ha en la transformació digital dels sectors tradicionals i les NGNs. Durant aquest llarg aprenentatge sobre les NGN a través de les diferents investigacions, es va poder observar una problemàtica que afectava de manera transversal als diferents camps d'aplicació de les NGNs i que aquesta podia tenir una afectació en aquests sectors. Aquesta problemàtica consisteix en el baix rendiment durant l'intercanvi de grans volums de dades sobre xarxes amb gran capacitat d'ample de banda i remotament separades geogràficament, conegudes com a xarxes elefant. Concretament, això afecta al cas d'ús d'intercanvi massiu de dades entre regions Cloud (Cloud Data Sharing use case). És per això que es va estudiar aquest cas d'ús i les diferents alternatives a nivell de protocols de transport,. S'estudien les diferents problemàtiques que pateixen els protocols i s'observa per què aquests no són capaços d'arribar a rendiments òptims. Deguda a aquesta situació, s'hipotetiza que la introducció de mecanismes que analitzen les mètriques de la xarxa i que exploten eficientment la capacitat de la mateixa milloren el rendiment dels protocols de transport sobre xarxes elefant heterogènies durant l'enviament massiu de dades. Primerament, es dissenya l’Adaptative and Aggressive Transport Protocol (AATP), un protocol de transport adaptatiu i eficient amb l'objectiu de millorar el rendiment sobre aquest tipus de xarxes elefant. El protocol AATP s'implementa i es prova en un simulador de xarxes i un testbed sota diferents situacions i condicions per la seva validació. Implementat i provat amb èxit el protocol AATP, es decideix millorar el propi protocol, Enhanced-AATP, sobre xarxes elefant heterogènies. Per això, es dissenya un mecanisme basat en el Jitter Ràtio que permet fer aquesta diferenciació. A més, per tal de millorar el comportament del protocol, s’adapta el seu sistema de fairness per al repartiment just dels recursos amb altres fluxos Enhanced-AATP. Aquesta evolució s'implementa en el simulador de xarxes i es realitzen una sèrie de proves. A l'acabar aquesta tesi, es conclou que les Xarxes de Nova Generació tenen molt recorregut i moltes coses a millorar causa de la transformació digital de la societat i de l'aparició de nova tecnologia disruptiva. A més, es confirma que la introducció de mecanismes específics en la concepció i operació dels protocols de transport millora el rendiment d'aquests sobre xarxes elefant heterogènies.Esta tesis por compendio centra sus contribuciones en el aprendizaje e innovación de las Redes de Nueva Generación. Es por ello que se proponen distintas contribuciones en diferentes ámbitos (Smart Cities, Smart Grids, Smart Campus, Smart Learning, Media, eHealth, Industria 4.0 entre otros) mediante la aplicación y combinación de diferentes disciplinas (Internet of Things, Building Information Modeling, Cloud Storage, Ciberseguridad, Big Data, Internet del Futuro, Transformación Digital). Concretamente, se detalla la monitorización sostenible del confort en el Smart Campus, la que se podría considerar mi aportación más representativa dentro de la conceptualización de Redes de Nueva Generación. Dentro de este innovador concepto de monitorización se integran diferentes disciplinas, para poder ofrecer información sobre el nivel de confort de las personas. Esta investigación demuestra el recorrido que existe en la transformación digital de los sectores tradicionales y las NGNs. Durante este largo aprendizaje sobre las NGN a través de las diferentes investigaciones, se pudo observar una problemática que afectaba de manera transversal a los diferentes campos de aplicación de las NGNs y que ésta podía tener una afectación en estos sectores. Esta problemática consiste en el bajo rendimiento durante el intercambio de grandes volúmenes de datos sobre redes con gran capacidad de ancho de banda y remotamente separadas geográficamente, conocidas como redes elefante, o Long Fat Networks (LFNs). Concretamente, esto afecta al caso de uso de intercambio de datos entre regiones Cloud (Cloud Data Data use case). Es por ello que se estudió este caso de uso y las diferentes alternativas a nivel de protocolos de transporte. Se estudian las diferentes problemáticas que sufren los protocolos y se observa por qué no son capaces de alcanzar rendimientos óptimos. Debida a esta situación, se hipotetiza que la introducción de mecanismos que analizan las métricas de la red y que explotan eficientemente la capacidad de la misma mejoran el rendimiento de los protocolos de transporte sobre redes elefante heterogéneas durante el envío masivo de datos. Primeramente, se diseña el Adaptative and Aggressive Transport Protocol (AATP), un protocolo de transporte adaptativo y eficiente con el objetivo maximizar el rendimiento sobre este tipo de redes elefante. El protocolo AATP se implementa y se prueba en un simulador de redes y un testbed bajo diferentes situaciones y condiciones para su validación. Implementado y probado con éxito el protocolo AATP, se decide mejorar el propio protocolo, Enhanced-AATP, sobre redes elefante heterogéneas. Además, con tal de mejorar el comportamiento del protocolo, se mejora su sistema de fairness para el reparto justo de los recursos con otros flujos Enhanced-AATP. Esta evolución se implementa en el simulador de redes y se realizan una serie de pruebas. Al finalizar esta tesis, se concluye que las Redes de Nueva Generación tienen mucho recorrido y muchas cosas a mejorar debido a la transformación digital de la sociedad y a la aparición de nueva tecnología disruptiva. Se confirma que la introducción de mecanismos específicos en la concepción y operación de los protocolos de transporte mejora el rendimiento de estos sobre redes elefante heterogéneas.This compendium thesis focuses its contributions on the learning and innovation of the New Generation Networks. That is why different contributions are proposed in different areas (Smart Cities, Smart Grids, Smart Campus, Smart Learning, Media, eHealth, Industry 4.0, among others) through the application and combination of different disciplines (Internet of Things, Building Information Modeling, Cloud Storage, Cybersecurity, Big Data, Future Internet, Digital Transformation). Specifically, the sustainable comfort monitoring in the Smart Campus is detailed, which can be considered my most representative contribution within the conceptualization of New Generation Networks. Within this innovative monitoring concept, different disciplines are integrated in order to offer information on people's comfort levels. . This research demonstrates the long journey that exists in the digital transformation of traditional sectors and New Generation Networks. During this long learning about the NGNs through the different investigations, it was possible to observe a problematic that affected the different application fields of the NGNs in a transversal way and that, depending on the service and its requirements, it could have a critical impact on any of these sectors. This issue consists of a low performance operation during the exchange of large volumes of data on networks with high bandwidth capacity and remotely geographically separated, also known as Elephant networks, or Long Fat Networks (LFNs). Specifically, this critically affects the Cloud Data Sharing use case. That is why this use case and the different alternatives at the transport protocol level were studied. For this reason, the performance and operation problems suffered by layer 4 protocols are studied and it is observed why these traditional protocols are not capable of achieving optimal performance. Due to this situation, it is hypothesized that the introduction of mechanisms that analyze network metrics and efficiently exploit network’s capacity meliorates the performance of Transport Layer protocols over Heterogeneous Long Fat Networks during bulk data transfers. First, the Adaptive and Aggressive Transport Protocol (AATP) is designed. An adaptive and efficient transport protocol with the aim of maximizing its performance over this type of elephant network.. The AATP protocol is implemented and tested in a network simulator and a testbed under different situations and conditions for its validation. Once the AATP protocol was designed, implemented and tested successfully, it was decided to improve the protocol itself, Enhanced-AATP, to improve its performance over heterogeneous elephant networks. In addition, in order to upgrade the behavior of the protocol, its fairness system is improved for the fair distribution of resources among other Enhanced-AATP flows. Finally, this evolution is implemented in the network simulator and a set of tests are carried out. At the end of this thesis, it is concluded that the New Generation Networks have a long way to go and many things to improve due to the digital transformation of society and the appearance of brand-new disruptive technology. Furthermore, it is confirmed that the introduction of specific mechanisms in the conception and operation of transport protocols improves their performance on Heterogeneous Long Fat Networks

Deep learning and reinforcement learning methods for grounded goal-oriented dialogue

Les systèmes de dialogues sont à même de révolutionner l'interaction entre l'homme et la machine. Pour autant, les efforts pour concevoir des agents conversationnels se sont souvent révélés infructueux, et ceux, malgré les dernières avancées en apprentissage profond et par renforcement. Les systèmes de dialogue palissent de devoir opérer sur de nombreux domaines d'application mais pour lesquels aucune mesure d'évaluation claire n'a été définie. Aussi, cette thèse s'attache à étudier les dialogues débouchant sur un objectif clair (goal-oriented dialogue) permettant de guider l'entrainement, et ceci, dans des environnements multimodaux. Plusieurs raisons expliquent ce choix : (i) cela contraint le périmètre de la conversation, (ii) cela introduit une méthode d'évaluation claire, (iii) enfin, l'aspect multimodal enrichie la représentation linguistique en reliant l'apprentissage du langage avec des expériences sensorielles. En particulier, nous avons développé GuessWhat?! (Qu-est-ce donc?!), un jeu imagé coopératif où deux joueurs tentent de retrouver un objet en posant une série de questions. Afin d’apprendre aux agents de répondre aux questions sur les images, nous avons développés une méthode dites de normalisation conditionnée des données (Conditional Batch Nornalization). Ainsi, cette méthode permet d'adapter simplement mais efficacement des noyaux de convolutions visuels en fonction de la question en cours. Enfin, nous avons étudié les tâches de navigation guidée par dialogue, et introduit la tâche Talk the Walk (Raconte-moi le Chemin) à cet effet. Dans ce jeu, deux agents, un touriste et un guide, s'accordent afin d'aider le touriste à traverser une reconstruction virtuelle des rues de New-York et atteindre une position prédéfinie.While dialogue systems have the potential to fundamentally change human-machine interaction, developing general chatbots with deep learning and reinforce-ment learning techniques has proven difficult. One challenging aspect is that these systems are expected to operate in broad application domains for which there is not a clear measure of evaluation. This thesis investigates goal-oriented dialogue tasks in multi-modal environments because it (i) constrains the scope of the conversa-tion, (ii) comes with a better-defined objective, and (iii) enables enriching language representations by grounding them to perceptual experiences. More specifically, we develop GuessWhat, an image-based guessing game in which two agents cooper-ate to locate an unknown object through asking a sequence of questions. For the subtask of visual question answering, we propose Conditional Batch Normalization layers as a simple but effective conditioning method that adapts the convolutional activations to the specific question at hand. Finally, we investigate the difficulty of dialogue-based navigation by introducing Talk The Walk, a new task where two agents (a “tourist” and a “guide”) collaborate to have the tourist navigate to target locations in the virtual streets of New York City

Cutting the Climate-Development Gordian Knot - <br />Economic options in a politically constrained world

http://www.cesifo.deCombating climate change cannot but be a cooperative venture amongst nations. Together with the problem posed by the withdrawal of the US from the Kyoto Protocol, the key challenge for winning the battle is the involvement of developing countries in efforts to alter their GHGs emissions trends. This involvement is necessary technically but also politically to bring the largest emitter of the planet back on the battle field. In the first section we draw on history to outline the intellectual underpinning of North/South divide around climate affairs. In the second section we show the economic basis for a leverage effect between development and climate policies. The third section ventures to propose some guidance to develop a viable climate regime strong enough to support an ambitious effort to decarbonize economies and we show that the Kyoto framework, once re-interpreted and amended is not so far from this working drawing