Relative used capital price, the measure of irreversibility, is fixed in almost all the investment literature. This dissertation introduces investment models with state-dependent irreversibility and tests whether these models outperform fixed irreversibility cases, at both the macro and micro levels. Since there is currently no historical data available on the issue of used capital prices, the first chapter uses an indirect inference procedure to estimate the cyclical property of irreversibility at the micro-level. In the second chapter, I propose a dynamic investment model with endogenous irreversibility arising from the lemons problem in the used capital market and examine the cyclical implication of irreversibility. Data evidence shows that capital reallocation, or used capital expenditure, is pro-cyclical. In a general equilibrium framework, the third chapter reveals that the investment model with state-dependent irreversibility explains this phenomenon while the model with fixed irreversibility does not. / text

Motivés par les développements récents dans le domaine des nanosciences, nous étudions les propriétés statistiques et thermodynamiques des systèmes mésoscopiques. En particulier, nous nous concentrons sur les résultats connus sous le nom de théorèmes de fluctuation. Ces relations donnent des prédictions sur le comportement de différents quantités dynamiques dans des situations loin de l'équilibre, tout en tenant compte des fluctuations de l'évolution temporelle. La première partie de notre étude est consacrée aux relations existants entre les fluctuations et la théorie de la réponse. Nous commençons par dériver une relation fonctionnelle pour les systèmes quantiques forcés dans le temps qui généralise l'égalité de Jarzynski et dont l'expansion en l'intensité du forçage permet de retrouver les résultats de la réponse linéaire. Nous poursuivons ensuite ces considérations en nous intéressant aux états stationnaires de non-équilibre. Ceci est réalisé dans le cadre des processus stochastiques, dans lequel nous dérivons une relation de fluctuation pour les courants de non-équilibre traversant le système. Cette relation lie explicitement les fluctuations aux forces thermodynamiques, ce qui nous permet de développer ses conséquences au niveau de la théorie de la réponse non-linéaire. De cette manière, nous obtenons de nouvelles relations liant fluctuations et coefficients de réponse dans le régime non-linéaire. Dans la deuxième partie de ce travail, nous développons une connexion récente liant l'irréversibilité au désordre dynamique. Nous présentons des résultats expérimentaux montrant que la production d'entropie s'exprime comme la différence de deux quantités mesurant la brisure de symétrie sous renversement du temps au niveau du désordre temporel. Nous étudions ensuite les conséquences de cette relation dans le contexte de l'énergétique du traitement de l'information. En particulier, nous présentons une généralisation du principe de Landauer pour l'effaçage d'information. De la même manière, nous relions la dissipation à la génération d'information par les entités biologiques.

This work assesses if a plausible theoretical thermo-chemical scheme can be conceived of, that is capable of extracting work from chemical reactants which can be compared with work produced by a fuel cell, when both processes are supplied with the same reactants. A theoretical process is developed to convert heat liberated from a chemical reaction to work. The hypothetical process is carried over a series of isothermal chemical reactor - heat engine combinations. Conducting the chemical reaction and work extraction over a series of temperature steps minimizes irreversibilities that result from the chemical reaction and heat transfer. Results obtained from the numerical calculations on the scheme confirm that when a large number of reactors-engine combinations are used, irreversibility of the proposed hypothetical reactor-engine combination can be reduced to zero. It is concluded from the results, that the theoretical model is as efficient as a fuel cell when both have the same chemical reaction under identical conditions. The effect of inert gas chemistry on the process has also been observed. It is determined from the results that the chemistry of the inert gas does not affect the proposed process. It is determined from results of a parametric study on the composition of inert gas, that the reduction of inert gas does not significantly improve the efficiency of the proposed process.

This work assesses if a plausible theoretical thermo-chemical scheme can be conceived of, that is capable of extracting work from chemical reactants which can be compared with work produced by a fuel cell, when both processes are supplied with the same reactants. A theoretical process is developed to convert heat liberated from a chemical reaction to work. The hypothetical process is carried over a series of isothermal chemical reactor - heat engine combinations. Conducting the chemical reaction and work extraction over a series of temperature steps minimizes irreversibilities that result from the chemical reaction and heat transfer. Results obtained from the numerical calculations on the scheme confirm that when a large number of reactors-engine combinations are used, irreversibility of the proposed hypothetical reactor-engine combination can be reduced to zero. It is concluded from the results, that the theoretical model is as efficient as a fuel cell when both have the same chemical reaction under identical conditions. The effect of inert gas chemistry on the process has also been observed. It is determined from the results that the chemistry of the inert gas does not affect the proposed process. It is determined from results of a parametric study on the composition of inert gas, that the reduction of inert gas does not significantly improve the efficiency of the proposed process.

Ο σκοπός αυτής της διατριβής είναι η υποδειγματοποίηση της επίδρασης της αβεβαιότητας στις αποφάσεις επένδυσης των επιχειρήσεων στην Ευρώπη και στην Ελλάδα. Για να γίνει αυτό, η διατριβή χτίζει ένα δυναμικό υπόδειγμα επένδυσης, όπου οι οικονομικές μεταβλητές, η αβεβαιότητα και η πραγματική επένδυση συνδέονται. Ελλείψει των αποκλίσεων από το νεοκλασικό παράδειγμα, η επένδυση αντιδρά θετικά στην αβεβαιότητα. Εντούτοις, όταν εισάγονται «τριβές» όπως ο ατελής ανταγωνισμός, η μη αναστρεψιμότητα του κεφαλαίου και οι φθίνουσες αποδόσεις κλίμακας, το θετικό πρόσημο της σχέσης επένδυσης-αβεβαιότητας εξασθενεί σταδιακά και τελικά γίνεται αρνητικό. Επιπλέον, αυτή η διατριβή παρέχει εμπειρικά ευρήματα υπέρ της θεωρητικής πρόβλεψης από τους Lee και Shin (2000) ότι η αβεβαιότητα μπορεί να ασκήσει ανομοιόμορφη επίδραση στην επένδυση δεδομένου ότι οι συναρτήσεις παραγωγής των ληπτών αποφάσεων εκθέτουν διαφορετικά μερίδια εργασίας. Εναλλακτικά μέτρα της αναστρεψιμότητας του κεφαλαίου υιοθετούνται, προερχόμενα είτε από την τεχνολογική είτε από τη συναλλακτική φύση της αναστρεψιμότητας. Ο τεχνολογικός ορισμός της αναστρεψιμότητας πηγάζει από τη δυνατότητα να υποκατασταθεί η εργασία με το κεφάλαιο. Από τη συναλλακτική σκοπιά, στατιστικά δεδομένα για δαπάνες σε μεταχειρισμένο κεφάλαιο και δαπάνες σε χρηματοδοτική μίσθωση χρησιμοποιήθηκαν ως έμμεσοι δείκτες του βαθμού αναστρεψιμότητας. Σύμφωνα με τη σχετική βιβλιογραφία, τα εμπειρικά μας αποτελέσματα δεικνύουν ότι η αρνητική επίπτωση της αβεβαιότητας στην επένδυση αυξάνεται μονοτονικά με το βαθμό της μη αναστρεψιμότητας. Η υπάρχουσα βιβλιογραφία που εστιάζει στην επίδραση της αβεβαιότητας στην επένδυση έχει αγνοήσει κατά ένα μεγάλο μέρος την ετερογένεια του κεφαλαίου. Αυτή η διατριβή καλύπτει αυτό το προφανές κενό, έχοντας ως σημείο αναφοράς το γεγονός ότι υπό την παρουσία πολλαπλών κεφαλαιουχικών αγαθών το συνολικό ποσοστό επένδυσης είναι το γινόμενο του εκτατικού και του εντατικού περιθωρίου. Κατόπιν, βασισμένοι στο επιχείρημα ότι η αβεβαιότητα έχει άμεση επίπτωση στο εκτατικό περιθώριο διερευνούμε εμπειρικά τη σχέση τους. Τα κύρια ευρήματά μας δείχνουν ότι η αβεβαιότητα ασκεί σημαντικά αρνητική επίδραση στον αριθμό των κεφαλαιουχικών αγαθών (εκτατικό περιθώριο) που ο λήπτης αποφάσεων αποφασίζει να επενδύσει. Αντίθετα το βάθος της επένδυσης (εκτατικό περιθώριο) βρέθηκε να μην αντιδρά στην αβεβαιότητα. Εφαρμόζουμε την τεχνική GMM των δυναμικών διαχρονικών και διαστρωματικών στοιχείων σε βιομηχανικό επίπεδο για τις περισσότερες από τις ηπειρωτικές ευρωπαϊκές χώρες για τρεις διαφορετικές χρονικές περιόδους, 1987-2002, 1989-2004 και 1995-2003. Επιπλέον, ένα δείγμα χρονικώς επαναλαμβανόμενων διαστρωματικών στοιχείων (ΧΕΔΣ) των ελληνικών βιομηχανιών μεταποίησης αξιοποιείται κατά τη διάρκεια της περιόδου 1993-2001. Τέλος, υιοθετούμε την υπό συνθήκη αβεβαιότητα προερχόμενη από ένα υπόδειγμα της μορφής Pooled-Panel GARCH. / The purpose of this thesis is to model the impact of uncertainty on the investment decisions of firms in Europe and in Greece. To do so, the thesis builds a dynamic investment model, where financial variables, uncertainty and real investment are linked. In the absence of deviations from the neoclassical paradigm investment reacts positively to uncertainty. However, as frictions are introduced such as imperfect competition, irreversibility of capital and decreasing returns-to-scale, the positive sign of the investment-uncertainty relationship gradually dies out and eventually turns negative. Furthermore, this thesis provides empirical evidence in favour of the theoretical prediction by Lee and Shin (2000) that uncertainty may exert a non-uniform impact on investment as decision makers' production functions exhibit differential labour shares. Alternative measures of capital irreversibility are employed, stemming from either the technological or the transactional nature of irreversibility. The technology-based definition views irreversibility in terms of the ability to substitute labour for capital. From a transactions-based concept, data on used capital investment expenditures and leasing penetration rates are employed as indirect indicators for the degree of irreversibility. Consistent with the relevant literature, the empirical results indicate that the negative effect of uncertainty on investment is monotonically increasing with the degree of irreversibility. The extant literature focusing on the impact of uncertainty on investment has largely ignored capital heterogeneity. This thesis fills this apparent gap having as departure point the fact that in the presence of multiple capital goods total investment rate is the product of the extensive and intensive margins. Then building on the argument that uncertainty affects directly the extensive margin we empirically explore their relationship. Our main results indicate that uncertainty exerts a significantly negative impact on the number of capital types (extensive margin) the decision maker decides to invest in. In contrast the depth of investment (intensive margin) is found to be insensitive to uncertainty. We employ a dynamic panel data methodology, the GMM estimation technique, on a panel data set at an industrial level for most of the continental European countries for the periods 1987-2002, 1989-2004 and 1995-2003. In addition, a panel data set of Greek manufacturing industries is also exploited over the period 1993-2001. Finally, conditional volatility is generated in a panel framework applying the Pooled-Panel GARCH method.

No description available.

<p>The hydrologic cycle may be described in essence as the process of water rising and falling in its various phases between land and atmosphere. In this minimal description of the hydrologic cycle two features come into focus: intermittency and irreversibility. In this dissertation intermittency and irreversibility are investigated broadly in the soil-plant-atmosphere system. The theory of intermittency and irreversibility is addressed here in three ways: (1) through its effect on components of the soil-plant-atmosphere system, (2) through development of a measure of the degree of irreversibility in time-series, and (3) by the investigation of the dynamical sources of this intermittency. First, soil infiltration and spring frost risk are treated as two examples of hydrologic intermittency with very different characters and implications for the soil plant system. An investigation of the water budget in simplified soil moisture models reveals that simple bucket models of infiltration perform well against more accurate representation of intra-storm infiltration dynamics in determining the surface water partitioning. Damaging spring frost is presented as a ``biologically-defined extreme event'' and thus as a more subtle form of hydrologic intermittency. This work represents the first theoretical development of a biologically-defined extreme and highlights the importance of the interplay between daily temperature mean and variance in determining the changes in damaging frost risk in a warming climate. Second, a statistical measure of directionality/asymmetry is developed for stationary time-series based on analogies with the theory of nonequilibrium thermodynamics. This measure is then applied to a set of DNA sequences as an example of a discrete sequence with limited state-space. The DNA sequences are found to be statistically asymmetric and further that the local degree of asymmetry is a reliable indicator of the coding/noncoding status of the DNA segment. Third, the phenomenology of rainfall occurrence is compared with canonical examples of dynamical intermittency to determine whether these simple dynamical features may display a dominant signature in rainfall processes. Summer convective rainfall is found to be broadly consistent with Type-III intermittency. Following on this result we studied daytime atmospheric boundary layer dynamics with a view toward developing simplified models that may further elucidate the interaction the interaction between land surface conditions and convective rainfall triggering.</p> / Dissertation

Nous avons étudié la dynamique de particules rigides et sphériques immergées dans un écoulement de cisaillement simple et oscillant à bas nombre de Reynolds. Les particules, au delà d’une déformation critique, se comportent de façon irréversible. La particules suivent alors un processus diffusif appelé: diffusion induite par cisaillement. Dans cette thèse, nous avons montré, par une approche numérique et expérimentale, que les collisions solides entre particules sont à l’origine de ce phénomène. Des simulations numériques ont été effectués afin d’évaluer l’importance relative des forces hydrodynamiques longues portées, des forces de lubrifications et des forces de contact. Deux expériences ont été effectuées afin de mettre en évidence l’influence des contacts solides entre particules. Nous avons étudié la dynamique de 3 particules soumises à un écoulement de cisaillement périodique. Les trajectoires des particules sont irréversibles durant le premier cycle et réversible pour les cycles suivants. En montrant que l’amplitude de l’irréversibilité est corrélée à la rugosité des particules, nous fournissons une preuve évidente que des collisions solides entre particules ont bien lieu et que ces collisions influencent la dynamique des particules. Effectuée dans une suspension homogène, le rôle des contacts a aussi été mis en évidence en montrant que l’amplitude critique de déformation dépend de la rugosité des particules. Un modèle géométrique simple qui considère des `particules effectives’ ayant un volume dépendant de l’amplitude de déformation et de la rugosité des particules, nous a permis de quantitativement reproduire les mesures expérimentales. / Even at low Reynolds number, particles within a shear flow exhibit irreversible dynamics. Many theories have been put forth to explain this phenomenon, the origin of irreversibility remains unclear. An integrated program of experimental and computational studies has been performed to assess the origin of the irreversible behavior of particles. Numerical simulations were used to evaluated the relative importance of long-range hydrodynamic interactions, lubrication, and contact forces. By isolating contribution of these interactions, we have shown that neither the long-range hydrodynamic interactions nor the lubrication are responsible for irreversibility. Solid contacts between particles largely dominate this phenomenon. However, producing realistic results requires both contact interactions and lubrication. Two different experiments were performed to address the role of contacts between particles in sheared suspensions. In the first experiment, the particle trajectories are irreversible during the first cycle but reversible for the next cycles. By showing that the magnitude of irreversibility increases with the particle roughness, we provide direct evidence that contacts occur in viscous flow. Experimental particle trajectories are well captured by the numerical model. In the second experiment, performed in a homogeneous suspension, the role of solid collisions was also revealed by showing that the critical strain amplitude depends on the particle roughness. A geometrical model based on the assumption that colliding particles produce irreversibility was derived. The model successfully reproduces the measured values of the critical strain amplitude.

Submitted by Cássia Santos (cassia.bcufg@gmail.com) on 2016-03-09T12:12:20Z No. of bitstreams: 2 Dissertação - Maria da Conceição Rodrigues dos Santos - 2010.pdf: 1309156 bytes, checksum: 587cba90cb284781d6bde1736fbfb384 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2016-03-10T11:50:54Z (GMT) No. of bitstreams: 2 Dissertação - Maria da Conceição Rodrigues dos Santos - 2010.pdf: 1309156 bytes, checksum: 587cba90cb284781d6bde1736fbfb384 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) / Made available in DSpace on 2016-03-10T11:50:54Z (GMT). No. of bitstreams: 2 Dissertação - Maria da Conceição Rodrigues dos Santos - 2010.pdf: 1309156 bytes, checksum: 587cba90cb284781d6bde1736fbfb384 (MD5) license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Previous issue date: 2010-11-30 / It is reference to this study the work of the physical chemist Ilya Prigonine based on ideas of complexity and chaos responsible for a deep change in science, originally triggered by thermodynamics followed by the theory of relativity and quantic physics. The study aims to examine the influence of the prigogineane work on the formation of the new episteme behind all these changes, in the face of the paradigmatic rupture of the contemporary thought. The study will also understand the new knowledge body which these investigated changes are about to model along with the issues of contemporary world, like those regarding the science and philosophy, the boundaries of growth, sustainable development and the emergency of a new model of rationality. / É referência para este estudo a obra do físico-químico Ilya Prigogine, nucleada pelas idéias de complexidade e caos, que apontam para uma profunda transformação da ciência, originariamente desencadeada pela termodinâmica, seguida de perto pela teoria da relatividade e pela física quântica. O trabalho tem por meta examinar o alcance da obra prigogineana na conformação da nova episteme que subjaz a tais mudanças, em face da ruptura paradigmática que instaura o pensamento contemporâneo. De resto, importará ao estudo entrever o novo corpo de saber que as mudanças investigadas estão a modelar, em concurso com questões prementes do mundo contemporâneo, como as que dizem respeito à crise na ciência e na filosofia, aos limites do crescimento, ao desenvolvimento sustentável e à emergência de um novo modelo de racionalidade.

A time-reversible Maxwell's demon is demonstrated which creates a density difference between two chambers initialized to have equal density. The density difference is estimated theoretically and confirmed by computer simulations. It is found that the reversible Maxwell's demon compresses phase space volume even though its dynamics are time reversible. The significance of phase space volume compression in operating a microscopic heat engine is also discussed.