Dissertations / Theses on the topic 'Gravity network'

Past focus in the panel gravity literature has been on multidimensional fixed effects specifications in an effort to accommodate heterogeneity. After introducing conventional multidimensional fixed effects, we find evidence of cross-sectional dependence in flows. We propose a simultaneous dependence gravity model that allows for network dependence in flows, along with computationally efficient Markov Chain Monte Carlo estimation methods that produce a Monte Carlo integration estimate of log-marginal likelihood useful for model comparison. Application of the model to a panel of trade flows points to network spillover effects, suggesting the presence of network dependence and biased estimates from conventional trade flow specifications. The most important sources of network dependence were found to be membership in trade organizations, historical colonial ties, common currency and spatial proximity of countries.
Series: Working Papers in Regional Science

Past focus in the panel gravity literature has been on multidimensional fixed effects specifications in an effort to accommodate heterogeneity. After introducing fixed effects for each origin- destination dyad and time-period speciffic effects, we find evidence of cross-sectional dependence in flows. We propose a simultaneous dependence gravity model that allows for network dependence in flows, along with computationally efficient MCMC estimation methods that produce a Monte Carlo integration estimate of log-marginal likelihood useful for model comparison. Application of the model to a panel of trade flows points to network spillover effects, suggesting the presence of network dependence and biased estimates from conventional trade flow specifications.
Series: Working Papers in Regional Science

AN ABSTRACT OF THE DISSERTATION OFDinush Lanka Panditharathna Jayasooriya Arachchilage, forthe Doctor of Philosophy degree in MATHEMATICS, presented on June 22, 2020 at SouthernIllinois University Carbondale.TITLE: SPIN NETWORK EVALUATION AND THE ASYMPTOTIC BEHAVIORMAJOR PROFESSOR: Dr. Jerzy KocikGraphically, a spin network is a trivalent graph with weights on each edge. At anyof the vertices, the sum of all three weights is even and the sum of any two weights isgreater than or equal to the remaining weight. If the spin network has no free ends, thenwe can evaluate the spin network. Here, we propose a method to evaluate some basic spinnetworks using the idea of Stirling triangle.Tangent circles with integer curvatures are a natural source to make a spin network.In particular, there are spin networks corresponding the Apollonian circle packing and theFord circle packing. We obtain the recurrence relations using the Descartes circle theoremand we evaluate the Apollonian spin network and the Ford circle spin network. We alsodiscuss the asymptotic behavior of the Ford circle spin network.

An efficient air transport system is an important part of social and economic development of Southern African Development Community (SADC). Efficient intra-SADC air service connections enhance regional integration, access to the global economy, international tourism and contribute towards the vision to establish the African Economic Community by 2034. SADC, in July 1998, embarked on liberalisation of the regional civil aviation sector in order to enhance the efficiency of air transport services. In the United States of America and European Union, the liberalisation of air transport has transformed civil aviation networks. The fragmentation of air service connections on the intra-SADC network in the midst of the liberalisation process is symptomatic of a poor implementation strategy coupled with air transport market imperfections. The purpose of this thesis is to examine, understand and explain the factors that influence the disintegration of the intra-SADC air transport network .The aim is to identify how regional air transport services can be transformed to meet the social and economic demands of the region. This research adopts network theory, as the conceptual framework of the investigation. Assuming a graph approaching maximal connection as the sought after state of affairs for SADC; this study benchmarked the post liberalisation network structure to the regional economic communities of ASEAN and MERCOSUR. The aim of the benchmarking is to identify the extend of the differences in air transport network in those two regions, resulting from the policies adopted and to establish how the SADC policies may be improved and implemented more efficiently. The findings of the study are that, in comparison to the two developing regions, SADC’s liberalisation measures have failed. The study developed and evaluated an econometric model which analysed demand patterns on the intra-SADC passenger air transport network. Although low levels of passenger demand seem to characterise the majority of SADC city-pairs, the study identified nodes with sufficient demand to justify direct connections which would in turn reduce network fragmentation. This research also establishes that the absence of a realistic detailed roadmap, an ill-defined programme of action and inadequate resources contributed to the failure of SADC’s liberalisation strategy. In its final sections, this study proposes an ideal demand-driven network configuration and offers specific recommendations to SADC member states for that network to be functional. The proposed network improves network connectivity from the current poor levels, where a connectivity measure of 15% suggests underdevelopment, to levels over 40%. The study however, acknowledges that air transport liberalisation does not necessarily guarantee equitable distribution of network efficiency in developing regions. There are communities that cannot sustain commercially viable air service connections without economic subvention, probably in the form of the Public Service Obligation (PSO) programme adopted in the EU.

Une étude d'un assemblage symétrique de trois 4-simplex en géométrie classique, de Regge et quantique. Nous étudions les propriétés géométriques et surtout la présence de courbure. Nous montrons que les géométries classique et de Regge de l'assemblage ont une courbure qui évolue en fonction de ses paramètres de bordure. Pour la géométrie quantique, une version euclidienne du modèle EPRL est utilisé avec une valeur pratique du paramètre Barbero-Immirzi pour définir l'amplitude de transition de l'ensemble et de ses composants. Un code C ++ est conçu pour calculer les amplitudes et étudier numériquement la géométrie quantique. Nous montrons qu'une géométrie classique, avec une courbure, émerge déjà à bas spin. Nous reconnaissons également l'apparition de configurations dégénérées et de leurs effets sur la géométrie attendue
A study of symmetrical assembly of three euclidean 4-simplices in classical, Regge and quantum geometry. We study the geometric properties and especially the presence of curvature. We show that classical and Regge geometry of the assembly have curvature which evolves in function of its boundary parameters. For the quantum geometry, a euclidean version of EPRL model is used with a convenient value of the Barbero-Immirzi parameter to define the transition amplitude of the assembly and its components. A C++ code is design for compute the amplitudes and study numerically the quantum geometry. We show that a classical geometry, with curvature, emerges already at low spin. We also recognize the appearance of the degenerate configurations and their effects on the expected geometry

Despite interest in the influence of religion on economic activity by early economists like Adam Smith, modern economists have done little research on the subject. In light of the apparent religious fervour in many parts of the global economy, economists' seeming lack of interest in studying how religious cultures enhance or retard the globalization of economic activity is especially surprising. In general, trade theories have given less weight towards the reason for trade explanation on demand side. As a contrary to H-O theory Linder had proposed a theoretically sound and empirically consistent trade theory with a new claim for the reasons why countries trade on the demand side. To fill this gap, I use international survey data on religiosity for a broad panel of countries trading with US to investigate the effects of church attendance and religious beliefs on trade. The beliefs are, in turn, the principal output of the religion sector, and the believer alignment to a specific denomination measures the inputs to this sector. Hence, I used an extended gravity model of international trade to control for a variety of factors that determine trade, and I used two regression methods, OLS and WLS, to exploit the model to its fullest. I find that the sharing of same religious cultures by people in different countries has a significantly positive influence on bilateral trade, all other things being equal. These results accord with a perspective in which religious beliefs influence individual traits that enhance trade and economic performance in general. And my attempt to magnify religion as a means to trade is only a derivation of Linder’s overlapping demand theory.

Thesis (Ph. D.)--Earth and Atmospheric Sciences, Georgia Institute of Technology, 2007.
Dr. Paul Steffes, Committee Member ; Dr. Irina Sokolik, Committee Member ; Dr. Robert Black, Committee Member ; Dr. Robert G. Roper, Committee Chair ; Dr. Derek Cunnold, Committee Member.

Baigiamajame magistro darbe atlikta Lietuvos ir Lenkijos gravimetrinių tinklų analizė. Apžvelgta IGSN 71 sunkio sistemos perdavimo metodika, išnagrinėtas gravimetrinių tinklų tikslumas. Pateikta informacija apie naujausią automatinį gravimetrą Scintrex CG-5, atlikta Lietuvos antrosios klasės gravimetrinio tinklo sudarymo metodikos detali analizė. Sudaryta gravimetrinių matavimų duomenų bazė, kuri gali būti naudojama gravimetrinių matavimų duomenų analizei. Panaudojant antrosios klasės gravimetrinio tinklo matavimų gravimetrais Scintrex CG-5 duomenis, atlikti, sunkio pagreičio tikslumo priklausomybės nuo matavimų skaičiaus punkte, tyrimai. Darbe gauti tyrimų rezultatai gali būti panaudoti tobulinant matavimų gravimetrais Scintrex CG -5 metodiką. Darbą sudaro 6 dalys: įvadas, 4 skyriai, išvados, literatūros sąrašas. Darbo apimtis – 98 p. , 56 iliustr., 22 lent., 28 bibliografiniai šaltiniai.
Thesis carried out in Lithuania and Poland, the gravimetric analysis of the network.Reviewed in IGSN 71gravity system of transmission methods, examined the accuracy of gravimetric networks. The information on the latest automatic gravimeter Scintrex CG-5, made second-class Lithuanian gravimetric network of methodology on a detailed analysis. Done gravimetric measurement database that can be used for gravimetric measurement data analysis. Using a second-class gravimeters gravimetric network Scintrex CG-5 data, perform, acceleration of gravity accuracy dependence on the number of measurements point out. We obtain the results can be used to improve measurement gravimeters Scintrex CG -5 methodology. The work consists of six parts: introduction, four sections, conclusions and the list of literature. Working volume - 98 pages, 56 drawings, 25 tables. The list of literature includes 28 bibliographical sources.

Une théorie fixé de la gravitation est loin d' être complète. La théorie plus prometteuse parmi ces théories de la gravité dans ce siècle est la relativité générale (RG), qui est toujours rencontre des obstacles par plusieurs problèmes. Les problèmes que nous soulignons dans cette thèse sont les aspects thermodynamiques et la quantification de la gravitation. Les tentatives proposées pour comprendre d'aspect thermodynamique de RG ont déjà été étudiés par la thermodynamique des trous noirs, alors que la théorie de la gravité quantique a déjà eu plusieurs des candidats, l'un d' entre eux était la gravité quantique à boucles (LQG), celui qui est la théorie base de notre travail. La théorie correcte de la gravité quantique devrait offrir une limite classique qui est correcte et consistent , ce qui évidemment , la relativité générale
A fixed theory of gravity is far from being complete. The most promising theory of gravity in this century is general relativity (GR), which is still plagued by several problems. The problems we highlight in this thesis are the thermodynamical aspects and the quantization of gravity. Attempts to understand the termodynamical aspect of GR have already been studied through the thermodynamics of black holes, while the theory of quantum gravity has already had several candidates, one of them being the canonical loop quantum gravity (LQG), which is the base theory in our work

In this dissertation, it is aimed to develop an approach for the trip distribution element which is one of the important phases of four-step travel demand modelling. The trip distribution problem using back-propagation artificial neural networks has been researched in a limited number of studies and, in a critically evaluated study it has been concluded that the artificial neural networks underperform when compared to the traditional models. The underperformance of back-propagation artificial neural networks appears to be due to the thresholding the linearly combined inputs from the input layer in the hidden layer as well as thresholding the linearly combined outputs from the hidden layer in the output layer. In the proposed neural trip distribution model, it is attempted not to threshold the linearly combined outputs from the hidden layer in the output layer. Thus, in this approach, linearly combined iv inputs are activated in the hidden layer as in most neural networks and the neuron in the output layer is used as a summation unit in contrast to other neural networks. When this developed neural trip distribution model is compared with various approaches as modular, gravity and back-propagation neural models, it has been found that reliable trip distribution predictions are obtained.

Title from PDF of title page (University of Missouri--Columbia, viewed on Feb 17, 2010). The entire thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file; a non-technical public abstract appears in the public.pdf file. Dissertation advisor: Dr. Vitor Trindade. Vita. Includes bibliographical references.

At the intersection of geography and public health, the field of spatial epidemiology seeks to use the tools of geospatial analysis to answer questions about disease. In this work we explore two areas: the use of geostatistical modeling as an extension of niche modeling, and the use of mobility metrics to augment modeling for epidemic responses. Niche modeling refers to the practice of using statistical methods to relate the underlying spatially distributed environmental variables to an outcome, typically presence or absence of a species. Such work is common in disease ecology, and often focuses on exploring the range of a disease vector or pathogen. The technique also allows one to explore the importance of each underlying regressor, and the effect it has on the outcome. We demonstrate that this concept can be extended, through geostatistical modeling, to explore non-logistic phenomena such as incidence. When combined with weather forecasts, such efforts can even predict incidence of an upcoming season, allowing us to estimate the total number of expected cases, and where we would expect to find them. We demonstrate this in Chapter 2, by forecasting the incidence of melioidosis in Australia given weather forecasts a year prior. We also evaluate the efficacy of this technique and explore the impact of environmental variables such as elevation on melioidosis. But these techniques are not limited to free-living and vector-borne pathogens. We theorize that they can also be applied to diseases that spread exclusively by person-to-person contact. Exploring this allows us to find areas of underreporting, as well as areas with unusual local forcing which might merit further investigation by the health department. We also explore this in Chapter 4, by relating the incidence of hepatitis C in rural Virginia to demographic data. The West African Ebola Outbreak of 2014 demonstrated the need to include mobility in predictive disease modeling. One can no longer assume that neglected tropical diseases will remain contained and immobile, and the assumption of random mixing across large areas is unwise. Our efforts with modeling mobility are twofold. In Chapter 3, we demonstrate the creation of mobility metrics from open source road and river network data. We then demonstrate the usefulness of such data in a meta-population patch model meant to forecast the spread of Ebola in the Democratic Republic of Congo. In Chapter 4, we also demonstrate that mobility data can be used to strengthen outbreak detection via hotspot analysis, and to augment incidence models by factoring in the incidence rates of neighboring areas. These efforts will allow health departments to more accurately forecast incidence, and more readily identify disease hotspots of atypical size and shape.
Doctor of Philosophy
The focus of this work is called “spatial epidemiology”, which combines geography with public health, to answer the where, and why, of disease. This is a growing field, and you’ve likely seen it in the news and media. Have you ever seen a map of the United States turning red in some virus disaster movie? The real thing looks a lot like that. After the Ebola outbreak of 2014, public health agencies wanted to know where the next one might hit. Now that there is another outbreak, we need to ask where and how will it spread? What areas are hardest hit, and how bad is it going to get? We can answer all these questions with spatial epidemiology. Our work adds to two aspects of spatial epidemiology: niche modeling, and mobility. We use niche modeling to determine where we could find certain diseases, usually those that are spread by insects or animals. Consider Lyme disease, you get it from the bite of a tick, and the tick gets it from a white-footed mouse. But both the mice and ticks only live in certain parts of the country. With niche modeling we can determine where those are, and we can also guess at what makes those areas attractive to the mice and ticks. Is it winter harshness, summer temperatures, rainfall, and/or elevation? Is it something else? In Chapter 2, we show that you can extend this idea. Instead of just looking at where the disease is, what if we could guess how many people will get infected? What if we could do so, a year in advance? We show that this can be done, but we need a good idea of what the weather will be like next year. In Chapter 4, we show that you can do the same thing with hepatitis C. Instead of Lyme’s ticks and mice, hepatitis C depends on drug-use, unregulated tattooing, and unsafe sex. And like with Lyme, these things are only found in certain places. Instead of temperature or rainfall, we now need to find areas with drug-problems and poverty. But we can get an idea of this from the Census Bureau, and we can make a map of hepatitis C as easily as we did for Lyme. But hepatitis C spreads person-to-person. So, we need some idea of how people move around the area. This is where mobility comes in. Mobility is important for most public health work, from detecting outbreaks to estimating where the disease will spread next. In Chapter 3, we show how one could create a mobility model for a rural area where few maps exist. We also show how to use that model to guess where the next cases of Ebola will show up. In Chapter 4, we show how you could use mobility to improve outbreak and hotspot detection. We also show how it’s used to help estimate the number of cases in an area. Because that number depends on how many cases are imported from the surrounding areas. And the only way to estimate that is with mobility.

Web-based social networks have become one of the most popular applications on the Internet in recent years. However, most of the social networks rely on some simplistic trust models to manage trust information of the users, which can cause problems ranging from unsatisfied user experience to exposure to malicious users. This thesis proposes a gravity-based trust model to enhance the aggregation of personal trust information into a subjective reputation system. This new model maps all users on the social network into n-dimensional Euclidean spaces based on their direct trust information, and creates a trust social neighborhood for each user. The reputation of a target user is determined by applying gravity model to the information from both target's and observer's trust social neighborhood. A prototype of this trust model is implemented in order to evaluate the effects of varying different parameters of the gravity-based trust model.

La gravité quantique à boucles a fourni un cadre d’étude particulièrement bien adapté aux théories de jauge définies sans métrique fixe et invariante sous difféomorphismes. Les excitations fondamentales de cette quantification sont appelées réseaux de spins, et dans le contexte de la relativité générale donnent un sens à la géométrie quantique au niveau canonique. Les mousses de spins constituent une sorte d’intégrale de chemins adaptée aux réseaux de spins, et donc destinée à permettre le calcul des amplitudes de transition entre ces états. Cette quantification est particulièrement efficace pour les théories des champs topologiques, comme Yang-Mills 2d, la gravité 3d ou les théories BF, et des modèles ont aussi été proposés pour la gravité quantique en dimension 4.Nous discutons dans cette thèse différentes méthodes pour l’étude des modèles de mousses de spins.Nous présentons en particulier des relations de récurrence sur les amplitudes de mousses de spins. De manière générique, elles codent des symétries classiques au niveau quantique, et sont susceptible de permettre de faire le lien avec les contraintes hamiltoniennes. De telles relations s’interprètent naturellement en termes de déformations élémentaires sur des structures géométriques discrètes, telles que simplicielles. Une autre méthode intéressante consiste à explorer la façon dont on peut réécrire les modèles de mousses de spins comme des intégrales de chemins pour des systèmes de géométries sur réseau, en s’inspirant à la fois des modèles topologiques et du calcul de Regge. Cela aboutit à une vision très géométrique des modèles, et fournit des actions classiques sur réseau dont on étudie les points stationnaires
Loop quantum gravity has provided us with a canonical framework especially devised for back-ground independent and diffeomorphism invariant gauge field theories. In this quantization the funda-mental excitations are called spin network states, and in the context of general relativity, they give ameaning to quantum geometry. Spin foams are a sort of path integral for spin network states, supposed to enable the computations of transition amplitudes between these states. The spin foam quantization has proved very efficient for topological field theories, like 2d Yang-Mills, 3d gravity or BF theories. Different models have also been proposed for 4-dimensional quantum gravity.In this PhD manuscript, I discuss several methods to study spin foam models. In particular, I present some recurrence relations on spin foam amplitudes, which generically encode classical symme-tries at the quantum level, and are likely to help fill the gap with the Hamiltonian constraints. These relations can be naturally interpreted in terms of elementary deformations of discrete geometric struc-tures, like simplicial geometries. Another interesting method consists in exploring the way spin foam models can be written as path integrals for systems of geometries on a lattice, taking inspiration from topological models and Regge calculus. This leads to a very geometric view on spin foams, and gives classical action principles which are studied in details

Designing monitoring networks that can discriminate among competing conceptual models is a key challenge for hydrologists. This issue is examined by considering the impact of network design on the utility of measurements for constraining hydrologic prediction uncertainty. Specifically, a three-staged approach was developed and is presented as a set of modeling case studies. The first case study presents a sensitivity analysis that examines conditions under which the proposed measurement method is likely to detect observations associated with the hydrologic process and properties of interest. This application is focused on the use of geomorphic information to estimate infiltration on arid alluvial fans.The second stage is an assessment of the likely utility of the measurement method to determine whether proposed measurements are likely to be useful for identifying hydraulic properties or hydrologic processes. This objective screening approach could reduce the number of unsuccessful uses of geophysical and other indirect measurement methods. A hypothetical site assessment examines whether the measurement method, temporal gravity change, is likely to detect signals associated with drawdown in an unconfined aquifer that occurs in response to pumping. Also, the utility of these measurements for identifying hydraulic conductivity and specific yield was considered.The third stage, an analysis of optimal network design, compares the projected measurement costs with the expected benefits of constraining hydrologic prediction uncertainty. The final case study presents a network design approach for a feasibility assessment of a proposed artificial recharge site. Predefined sets of proposed measurements of temporal gravity change were considered for various measurement times. An ensemble approach was used to assess the likely impact of measurement error on prediction error and uncertainty for different combinations of measurement sets. The ensemble of prediction errors was translated to probability-weighted performance costs for each measurement set using a cost function. Total cost was calculated as the sum of the performance and measurement costs. The optimal measurement set, defined as the set with the lowest total cost, depends on the prediction of interest, the per measurement cost, the maximum risk-based cost associated with the hydrologic prediction, and the treatment of uncertainty in defining performance costs.

Les mousses de spin fournissent un formalisme d’intégrale de chemin pour la gravité. Ils décrivent la structure quantique de l’espace-temps et l’évolution temporelle des états cinématiques de la gravité quantique à boucles. Cette quantification covariante est basée sur l’écriture de la relativité générale comme une théorie topologique contrainte, où les contraintes introduisent les degrés de libertés locaux. Dans cette thèse, une manière originale d’imposer les contraintes grâce à des oscillateurs harmoniques est proposée. Un modèle de mousse de spin pour la gravité quantique est cohérent s’il peut être relié à l’approche canonique à boucles et possède la bonne limite semi-classique. Nous donnons ici un lien explicite entre les états cinématiques de la gravité quantique à boucles et les états frontières d’une mousse de spin. Nous proposons aussi de nouvelles techniques pour calculer le développement asymptotique semi-classique des amplitudes de transitions de la gravité quantique 3d
The spinfoam framework is a proposal for a regularized path integral for quantum gravity. Spinfoams define quantum space-time structures describing the evolution in time of the spin network states for quantum geometry derived from Loop Quantum Gravity (LQG). The construction is based on the formulation of General Relativity as a topological theory plus the so-called simplicity constraints which introduce local degrees of freedom. In this PhD manuscript, an original way to impose the simplicity constraints in 4d Euclidean gravity using harmonic oscillators is proposed. A consistent spinfoam model for quantum gravity has to be connected to LQG and must have the right semi-classical limit. An explicit map between the spin network states of LQG and the boundary states of spinfoam models is given. New techniques to compute semiclassical asymptotic expressions for the transition amplitudes of 3d quantum gravity and to extract semi-classical information from a spinfoam model are introduced

Le principal objectif de ce travail est l’étude de l’influence de la pesanteur sur la mécanique

respiratoire et le contrôle de la respiration, ainsi que sur les interactions cardio-respiratoires pendant les différents stades du sommeil.

Le chapitre introductif présente le contexte général et les objectifs de la thèse. Des sections abordant le sommeil, la respiration, et l’interaction cardio-respiratoire y sont présentées, résumant l’état actuel des connaissances sur les effets de la pesanteur sur chacun de ces systèmes.

Dans le deuxième chapitre, l’expérience “Sleep and Breathing in microgravity”, qui constitue la source des données à la base de ce travail, est présentée en détail.

L’étude des signaux de longue durée requiert avant tout de disposer d’outils performants

d’analyse des signaux. La première partie de la thèse présente en détail deux algorithmes :un

algorithme de détection automatique d’événements respiratoires (inspiration / expiration)

basé sur des réseaux neuronaux artificiels, et un algorithme de quantification de l’amplitude

et de la phase de l’arythmie sinusale pendant le sommeil, utilisant la méthode des ondelettes.

La validation de chaque algorithme est présentée, et leur performance évaluée. Cette partie

inclut aussi des courtes introductions théoriques aux réseaux de neurones artificiels ainsi

qu’aux méthodes d’analyse temps–fréquence (Fourier et ondelettes).

Une approche similaire à celle utilisée pour la détection automatique d’événements respiratoires a été appliquée à la détection d’événements dans des signaux de vitesse du sang

dans l’artère cérébrale moyenne, mesures obtenues par Doppler transcrânien. Ceci est le

sujet de la thèse annexe.

Ces deux algorithmes ont été appliqués aux données expérimentales pour extraire des

informations physiologiques quant à l’impact de la pesanteur sur la mécanique respiratoire et

l’interaction cardio-respiratoire. Ceci constitue la deuxième partie de la thèse. Un chapitre

est consacré aux effets de l’apesanteur sur la mécanique respiratoire pendant le sommeil.

Ce chapitre a mis en évidence, pour tous les stades de sommeil, une augmentation de la

contribution abdominale en microgravité, suivi d’un retour progressif vers des valeurs observées avant le vol. L’augmentation initiale était attendue, mais l’adaptation progressive

observée ne peut pas être expliquée par un effet purement mécanique, et nous suggère la

présence d’un mécanisme d’adaptation central. Un deuxième chapitre présente les résultats

comparant l’arythmie sinusale pendant le sommeil avant le vol, en apesanteur et après le retour sur terre. Le rythme cardiaque pendant le sommeil dans l’espace présente une moindre

variabilité. Les différences NREM–REM observées sur terre pour les influences vagales et sympathiques sont accentuées dans l’espace. Aucun changement significatif n’est présent pour

le gain et la différence de phase entre les les signaux cardiaque et respiratoire en comparant

le sommeil sur terre et en apesanteur.

La dissertation termine par une discussion générale du travail effectué, incluant les prin-

cipales conclusions ainsi que les perspectives qui en découlent.
Doctorat en Sciences biomédicales et pharmaceutiques
info:eu-repo/semantics/nonPublished

The main objective of this thesis is to carry out a multidisciplinary study of the behavior of microblog users. To that end we first explore several user behavior patterns employing data mining techniques. Then we use social science theories of culture and socio-economic indicators to better understand differences and similarities of user behavior across countries. We found several insights on user behavior such as (i) social link recommendations made by current friends have a large effect on link formation and the accepted recommendations have more longevity than other links; (ii) as users mature, they evolve to adopt microblogs as a news media rather than a social network; (iii) the collective behavior of users from some countries standout, based on certain special characteristics such as conversations, reciprocity, etc.; (iv) national culture determines the temporal patterns with which users post, or the extent to which they mention, follow, recommend and befriend others; and (v) socio-economic and cultural features improve the prediction of communication strength among users from different countries.
El objetivo principal de esta tesis es realizar un estudio multidisciplinario sobre la conducta de los usuarios en microblogs. Para ello primero exploramos varios patrones de comportamiento de usuario usando técnicas de minería de datos. Luego usamos algunas teorías de las ciencias sociales en cultura e indicadores socioeconómicos para comprender mejor las diferencias y similitudes del comportamiento de los usuarios en diferentes países. Encontramos varios resultados interesantes sobre el comportamiento del usuario, tales como, (i) las recomendaciones de enlaces sociales hechas por amigos tienen un gran efecto sobre la formación de enlaces sociales y las recomendaciones aceptadas tienen más longevidad que otros enlaces; (ii) a medida que los usuarios maduran, estos evolucionan a usar los microblogs como un medio de comunicación en lugar de una red social; (iii) el comportamiento colectivo de los usuarios de algunos países se destaca en base a ciertas características peculiares, tales como conversaciones, reciprocidad, etc.; (iv) la cultura nacional determina los patrones temporales con los que los usuarios publican mensajes, o el grado en que se mencionan, recomiendan y siguen los unos a los otros; y (v) las características socioeconómicas y culturales ayudan a mejorar la predicción de la intensidad de la comunicación entre los usuarios de diferentes países.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-04T20:23:16Z No. of bitstreams: 1 claudioluizdecarvalho.pdf: 1237703 bytes, checksum: 32187853fc58c41f6d31975a9a0c1b13 (MD5)
Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-13T16:23:21Z (GMT) No. of bitstreams: 1 claudioluizdecarvalho.pdf: 1237703 bytes, checksum: 32187853fc58c41f6d31975a9a0c1b13 (MD5)
Made available in DSpace on 2016-07-13T16:23:21Z (GMT). No. of bitstreams: 1 claudioluizdecarvalho.pdf: 1237703 bytes, checksum: 32187853fc58c41f6d31975a9a0c1b13 (MD5) Previous issue date: 2012-04-23
CAPES - Coordenação de Aperfeiçoamento de Pessoal de Nível Superior
Resumo: A literatura de transporte raramente considera a influência da interação espacial e das redes sociais sobre os fluxos de passageiros. A presente dissertação possui como objetivo a estimação da demanda de transporte aéreo por meio de dados na forma de fluxos de passageiros entre pares origem-destino (O-D), utilizando como método de estimação o modelo gravitacional ampliado, incorporando efeitos fixos, espaciais e de rede. Em relação ao modelo gravitacional, sua especificação se mostrou adequada nas estimações mostrando que tanto o tamanho dos municípios quanto a distância que os separa são variáveis relevantes para explicar o fluxo de passageiros entre os mesmos. O que mostra que a ―massa‖ do município, o PIB ou a população, são os principais determinantes para o incremento de passageiros em rotas aéreas, e que a distância se mostra uma restrição relevante para este incremento. Além disso, as variáveis que captam a autocorrelação espacial no modelo, ainda que menos significativas, são relevantes para explicar o fluxo de passageiros.
Abstract: The transport demand literature has rarely considered the influence of geographical interation or social network on passenger flows. This work aims to estimate air transport demand using an extended gravity model, controlling for spatial and network effects. As to the Gravity Model, the extended specification has been proper and has demonstrated the relevance of economic masses (GDP and population) as well the distance to explain passengers flows between the cities. Although spatial autocorrelation is a little significant, it is still useful to explain air passengers flow demand.

L’Intelligenza Artificiale è un campo dell’informatica che da tempo si afferma come valido strumento alternativo per la risoluzione di problemi tipicamente riservati esclusivamente all’intelletto umano. Se in principio gli algoritmi sfruttati nel campo dell’Intelligenza Artificiale erano basati su insiemi di regole codificate da esperti del dominio di applicazione dell’algoritmo, con l’arrivo del secondo millennio questo approccio è stato superato in favore di algoritmi che sfruttano grandi quantità di dati ed elevata potenza di calcolo per fare scelte ottimali. Un esempio di questo approccio può essere Deep Blue, che nel 1996, anche grazie ad un database di 4mila aperture e un’architettura che permetteva 11 GFLOPS fu la prima macchina a vincere una partita a scacchi contro un grande maestro. Col passare degli anni, l’aumentare degli investimenti e della ricerca, questo approccio ha portato alla strutturazione del campo dell’Apprendimento Automatico (Machine Learning, in inglese) dal quale sono scaturiti numerosi avanzamenti che hanno influenzato una moltitudine di ambiti: dall’agricoltura di precisione alla traduzione automatica, dal riconoscimento di frodi con carte di credito alla farmaceutica, dal marketing alla visione artificiale e molti altri, inclusa la medicina. Questo lavoro si concentra su proprio questioni relative al campo della medicina. In particolare si occupa di provare a riconoscere se le stenosi coronariche di un paziente sono gravi o meno attraverso l’uso di angiografie coronariche invasive e tomografie coronariche angiografiche; in maniera da diminuire delle angiografie coronariche invasive effettuate su pazienti che non ne hanno davvero bisogno.

Le but de cette thèse est de développer des outils statistiques permettant d'initialiser et de calibrer les modèles de microsimulation dynamique stochastique, en partant de l'exemple du modèle SimVillages (développé dans le cadre du projet Européen PRIMA). Ce modèle couple des dynamiques démographiques et économiques appliquées à une population de municipalités rurales. Chaque individu de la population, représenté explicitement dans un ménage au sein d'une commune, travaille éventuellement dans une autre, et possède sa propre trajectoire de vie. Ainsi, le modèle inclut-il des dynamiques de choix de vie, d'étude, de carrière, d'union, de naissance, de divorce, de migration et de décès. Nous avons développé, implémenté et testé les modèles et méthodes suivants : 1 / un modèle permettant de générer une population synthétique à partir de données agrégées, où chaque individu est membre d'un ménage, vit dans une commune et possède un statut au regard de l'emploi. Cette population synthétique est l'état initial du modèle. 2 / un modèle permettant de simuler une table d'origine-destination des déplacements domicile-travail à partir de données agrégées. 3 / un modèle permettant d'estimer le nombre d'emplois dans les services de proximité dans une commune donnée en fonction de son nombre d'habitants et de son voisinage en termes de service. 4 / une méthode de calibration des paramètres inconnus du modèle SimVillages de manière à satisfaire un ensemble de critères d'erreurs définis sur des sources de données hétérogènes. Cette méthode est fondée sur un nouvel algorithme d'échantillonnage séquentiel de type Approximate Bayesian Computation.

Les méthodes géophysiques aéroportées sont très utilisées pour la prospection du sous-sol à l'échelle régionale, permettant ainsi de couvrir de grandes surfaces en particulier les zones difficiles d'accès. Le sujet de thèse concerne le développement de techniques d'interprétation des données géophysiques pour le problème des ressources naturelles et de l'environnement. La première partie de cette thèse concerne le développement d'une méthode de calcul direct des composantes des champs gravimétrique et magnétique à partir d'une structure (corps) géologique modélisé(e) par une grille à base de tétraèdres, ce qui permet de représenter des modèles géologiques très complexes particulièrement en présence de zones faillées et hétérogènes avec un nombre d'éléments optimal. Plusieurs techniques d'inversions utilisent des contraintes mathématiques pour la résolution du problème inverse en modélisation. Ces contraintes permettent de réduire le nombre de modèles possibles. Cependant les solutions proposées appelées aussi « le modèle le plus probable » présentent des solutions lisses, ce qui est loin de représenter la réalité géologique. Pour éluder ce problème, les deuxièmes et troisièmes parties de la thèse proposent des améliorations majeures du processus d'inversion par l'utilisation des méthodes géostatistiques telles que la Simulation Gaussienne Séquentielle ou la Co-Simulation dans le cas d'une inversion conjointe afin d'estimer les probabilités a posteriori des modèles simulés. La quatrième partie de ce mémoire présente une alternative à la simulation de plusieurs variables. L'apprentissage du réseau de neurones supervisé par un certain nombre de points permet d'établir une relation entre les différentes variables
In recent years with the technology developments, airborne geophysical methods (gravity, magnetic, and electromagnetic) are widely used in the natural resource exploration at the regional scale. It covers large areas particularly in the areas with difficult access. The first part of this thesis consist on the development of new forward modeling algorithm for the calculation of the components of the gravity and magnetic fields based on a tetrahedron grid. The tetrahedral mesh allows the representation of very complex geological models holding many heterogeneous and faulted zones with an optimal number of elements, this reduces significantly the time calculation. Several inversion techniques use mathematical constraints for the resolution of the inverse problem in order to reduce the number of possible models. However the proposed solutions called also "the most probable model" provide a smooth solutions that cannot represent the geological reality. To circumvent this problem in the second and the third parts of this thesis, we made two major improvements. The first, we integrate Sequential Gaussian Simulation into the inversion procedure to determine a possible distributions of a single property. The second is that we used the Co-Simulation in the case of joint inversion to estimate a posteriori probabilities of the simulated models. The last part of this thesis presents an alternative to the several variables simulation, supervised learning of neural networks allows to establish a relationship between the different variables

Within the paradigm of sustainability, this thesis aims to provide complementary views to the conventional engineering in order to put forward tools that facilitate, on the one hand the search of solutions to improve the design of high-voltage power lines , and on the other hand to optimize their networks. As per the improving of a high-voltage line design, Scaling Laws and Gravity Models are used to provide new variables to estimate calculation of the electricity demand of a certain area. This article proposes modifications to the vector diagram of a transmission line operation, known as a Perrine-Baum Diagram to incorporate the new variables proposed with the objective to use this diagram as an application tool in real projects. Regarding the electric power networks, this work applies the analysis tools provided by the theories of Complex Networks to study its topology and spatial features in order to suggest more optimal designs.
Dins del paradigma de la sostenibilitat, aquesta tesi pretén aportar punts de vista complementaris als de l’enginyeria convencional amb l’objectiu de proposar eines que facilitin per una banda, trobar solucions per millorar el disseny de les línies elèctriques d’alta tensió, i per una altra optimitzar les xarxes constituïdes per aquestes. Pel que fa a la millora del disseny d’una línia d’alta tensió, s’han utilitzat les teories de les Lleis d’Escala i els Models Gravitacionals per aportar noves variables als càlculs de previsió de demanda elèctrica d’una regió. S’han proposat modificacions al diagrama vectorial de funcionament d’una línia elèctrica, conegut com a Diagrama Perrine-Baum, per incorporar les noves variables proposades amb l’objectiu que aquest diagrama pugui ser una eina d’aplicació en projectes reals. Pel que fa a les xarxes elèctriques s’han aplicat les eines d’anàlisi aportades per les teories de Xarxes Complexes per estudiar la seva topologia i les característiques espacials, amb l’objectiu de proposar dissenys més òptims.

Nowadays, small autonomous underwater robots are strongly preferred for remote exploration of unknown and unstructured environments. Such robots allow the exploration and monitoring of underwater environments where a long term underwater presence is required to cover a large area. Furthermore, reducing the robot size, embedding electrical board inside and reducing cost are some of the challenges designers of autonomous underwater robots are facing. As a key device for reliable operation-decision process of autonomous underwater robots, a relatively fast and cost effective controller based on Fuzzy logic and proportional-integral-derivative method is proposed in this thesis. It efficiently models nonlinear system behaviors largely present in robot operation and for which mathematical models are difficult to obtain. To evaluate its response, the fault finding test approach was applied and the response of each task of the robot depicted under different operating conditions. The robot performance while combining all control programs and including sensors was also investigated while the number of program codes and inputs were increased.

In the last 50 years, flooding has figured as the most frequent and widespread natural disaster globally. Extreme precipitation events stemming from climate change could alter the hydro-geological regime resulting in increased flood risk. Near real-time precipitation monitoring at local scale is essential for flood risk mitigation in urban and suburban areas, due to their high vulnerability. Presently, most of the rainfall data is obtained from ground‐based measurements or remote sensing that provide limited information in terms of temporal or spatial resolution. Other problems may be due to the high costs. Furthermore, rain gauges are unevenly spread and usually placed away from urban centers. In this context, a big potential is represented by the use of innovative techniques to develop low-cost monitoring systems. Despite the diversity of purposes, methods and epistemological fields, the literature on the visual effects of the rain supports the idea of camera-based rain sensors but tends to be device-specific. The present thesis aims to investigate the use of easily available photographing devices as rain detectors-gauges to develop a dense network of low-cost rainfall sensors to support the traditional methods with an expeditious solution embeddable into smart devices. As opposed to existing works, the study focuses on maximizing the number of image sources (like smartphones, general-purpose surveillance cameras, dashboard cameras, webcams, digital cameras, etc.). This encompasses cases where it is not possible to adjust the camera parameters or obtain shots in timelines or videos. Using a Deep Learning approach, the rainfall characterization can be achieved through the analysis of the perceptual aspects that determine whether and how a photograph represents a rainy condition. The first scenario of interest for the supervised learning was a binary classification; the binary output (presence or absence of rain) allows the detection of the presence of precipitation: the cameras act as rain detectors. Similarly, the second scenario of interest was a multi-class classification; the multi-class output described a range of quasi-instantaneous rainfall intensity: the cameras act as rain estimators. Using Transfer Learning with Convolutional Neural Networks, the developed models were compiled, trained, validated, and tested. The preparation of the classifiers included the preparation of a suitable dataset encompassing unconstrained verisimilar settings: open data, several data owned by National Research Institute for Earth Science and Disaster Prevention - NIED (dashboard cameras in Japan coupled with high precision multi-parameter radar data), and experimental activities conducted in the NIED Large Scale Rainfall Simulator. The outcomes were applied to a real-world scenario, with the experimentation through a pre-existent surveillance camera using 5G connectivity provided by Telecom Italia S.p.A. in the city of Matera (Italy). Analysis unfolded on several levels providing an overview of generic issues relating to the urban flood risk paradigm and specific territorial questions inherent with the case study. These include the context aspects, the important role of rainfall from driving the millennial urban evolution to determining present criticality, and components of a Web prototype for flood risk communication at local scale. The results and the model deployment raise the possibility that low‐cost technologies and local capacities can help to retrieve rainfall information for flood early warning systems based on the identification of a significant meteorological state. The binary model reached accuracy and F1 score values of 85.28% and 0.86 for the test, and 83.35% and 0.82 for the deployment. The multi-class model reached test average accuracy and macro-averaged F1 score values of 77.71% and 0.73 for the 6-way classifier, and 78.05% and 0.81 for the 5-class. The best performances were obtained in heavy rainfall and no-rain conditions, whereas the mispredictions are related to less severe precipitation. The proposed method has limited operational requirements, can be easily and quickly implemented in real use cases, exploiting pre-existent devices with a parsimonious use of economic and computational resources. The classification can be performed on single photographs taken in disparate conditions by commonly used acquisition devices, i.e. by static or moving cameras without adjusted parameters. This approach is especially useful in urban areas where measurement methods such as rain gauges encounter installation difficulties or operational limitations or in contexts where there is no availability of remote sensing data. The system does not suit scenes that are also misleading for human visual perception. The approximations inherent in the output are acknowledged. Additional data may be gathered to address gaps that are apparent and improve the accuracy of the precipitation intensity prediction. Future research might explore the integration with further experiments and crowdsourced data, to promote communication, participation, and dialogue among stakeholders and to increase public awareness, emergency response, and civic engagement through the smart community idea.
Negli ultimi 50 anni, le alluvioni si sono confermate come il disastro naturale più frequente e diffuso a livello globale. Tra gli impatti degli eventi meteorologici estremi, conseguenti ai cambiamenti climatici, rientrano le alterazioni del regime idrogeologico con conseguente incremento del rischio alluvionale. Il monitoraggio delle precipitazioni in tempo quasi reale su scala locale è essenziale per la mitigazione del rischio di alluvione in ambito urbano e periurbano, aree connotate da un'elevata vulnerabilità. Attualmente, la maggior parte dei dati sulle precipitazioni è ottenuta da misurazioni a terra o telerilevamento che forniscono informazioni limitate in termini di risoluzione temporale o spaziale. Ulteriori problemi possono derivare dagli elevati costi. Inoltre i pluviometri sono distribuiti in modo non uniforme e spesso posizionati piuttosto lontano dai centri urbani, comportando criticità e discontinuità nel monitoraggio. In questo contesto, un grande potenziale è rappresentato dall'utilizzo di tecniche innovative per sviluppare sistemi inediti di monitoraggio a basso costo. Nonostante la diversità di scopi, metodi e campi epistemologici, la letteratura sugli effetti visivi della pioggia supporta l'idea di sensori di pioggia basati su telecamera, ma tende ad essere specifica per dispositivo scelto. La presente tesi punta a indagare l'uso di dispositivi fotografici facilmente reperibili come rilevatori-misuratori di pioggia, per sviluppare una fitta rete di sensori a basso costo a supporto dei metodi tradizionali con una soluzione rapida incorporabile in dispositivi intelligenti. A differenza dei lavori esistenti, lo studio si concentra sulla massimizzazione del numero di fonti di immagini (smartphone, telecamere di sorveglianza generiche, telecamere da cruscotto, webcam, telecamere digitali, ecc.). Ciò comprende casi in cui non sia possibile regolare i parametri fotografici o ottenere scatti in timeline o video. Utilizzando un approccio di Deep Learning, la caratterizzazione delle precipitazioni può essere ottenuta attraverso l'analisi degli aspetti percettivi che determinano se e come una fotografia rappresenti una condizione di pioggia. Il primo scenario di interesse per l'apprendimento supervisionato è una classificazione binaria; l'output binario (presenza o assenza di pioggia) consente la rilevazione della presenza di precipitazione: gli apparecchi fotografici fungono da rivelatori di pioggia. Analogamente, il secondo scenario di interesse è una classificazione multi-classe; l'output multi-classe descrive un intervallo di intensità delle precipitazioni quasi istantanee: le fotocamere fungono da misuratori di pioggia. Utilizzando tecniche di Transfer Learning con reti neurali convoluzionali, i modelli sviluppati sono stati compilati, addestrati, convalidati e testati. La preparazione dei classificatori ha incluso la preparazione di un set di dati adeguato con impostazioni verosimili e non vincolate: dati aperti, diversi dati di proprietà del National Research Institute for Earth Science and Disaster Prevention - NIED (telecamere dashboard in Giappone accoppiate con dati radar multiparametrici ad alta precisione) e attività sperimentali condotte nel simulatore di pioggia su larga scala del NIED. I risultati sono stati applicati a uno scenario reale, con la sperimentazione attraverso una telecamera di sorveglianza preesistente che utilizza la connettività 5G fornita da Telecom Italia S.p.A. nella città di Matera (Italia). L'analisi si è svolta su più livelli, fornendo una panoramica sulle questioni relative al paradigma del rischio di alluvione in ambito urbano e questioni territoriali specifiche inerenti al caso di studio. Queste ultime includono diversi aspetti del contesto, l'importante ruolo delle piogge dal guidare l'evoluzione millenaria della morfologia urbana alla determinazione delle criticità attuali, oltre ad alcune componenti di un prototipo Web per la comunicazione del rischio alluvionale su scala locale. I risultati ottenuti e l'implementazione del modello corroborano la possibilità che le tecnologie a basso costo e le capacità locali possano aiutare a caratterizzare la forzante pluviometrica a supporto dei sistemi di allerta precoce basati sull'identificazione di uno stato meteorologico significativo. Il modello binario ha raggiunto un'accuratezza e un F1-score di 85,28% e 0,86 per il set di test e di 83,35% e 0,82 per l'implementazione nel caso di studio. Il modello multi-classe ha raggiunto un'accuratezza media e F1-score medio (macro-average) di 77,71% e 0,73 per il classificatore a 6 vie e 78,05% e 0,81 per quello a 5 classi. Le prestazioni migliori sono state ottenute nelle classi relative a forti precipitazioni e assenza di pioggia, mentre le previsioni errate sono legate a precipitazioni meno estreme. Il metodo proposto richiede requisiti operativi limitati, può essere implementato facilmente e rapidamente in casi d'uso reali, sfruttando dispositivi preesistenti con un uso parsimonioso di risorse economiche e computazionali. La classificazione può essere eseguita su singole fotografie scattate in condizioni disparate da dispositivi di acquisizione di uso comune, ovvero da telecamere statiche o in movimento senza regolazione dei parametri. Questo approccio potrebbe essere particolarmente utile nelle aree urbane in cui i metodi di misurazione come i pluviometri incontrano difficoltà di installazione o limitazioni operative o in contesti in cui non sono disponibili dati di telerilevamento o radar. Il sistema non si adatta a scene che sono fuorvianti anche per la percezione visiva umana. I limiti attuali risiedono nelle approssimazioni intrinseche negli output. Per colmare le lacune evidenti e migliorare l'accuratezza della previsione dell'intensità di precipitazione, sarebbe possibile un'ulteriore raccolta di dati. Sviluppi futuri potrebbero riguardare l'integrazione con ulteriori esperimenti in campo e dati da crowdsourcing, per promuovere comunicazione, partecipazione e dialogo aumentando la resilienza attraverso consapevolezza pubblica e impegno civico in una concezione di comunità smart.

碩士
國立交通大學
土木工程研究所
86
This study adjusts the gravity measurements collected by Base Survey Battalion using least - squares with constraints. The estimated instrument accuracy is 0.02 mgal and the error estimates of the gravity values at given gravity stations are 0.1 to 0.3 mgal. The adjusted gravity data are combined with existing land gravity data and shipborne gravity data. Together with altimeter data, the combined gravity data are used in the following studies: l. A geoid model of Taiwan is computed by least-squares collocation. The geoid model and GPS heights yield orthometric heights with accuracies of 5mm√K in flat areas which fulfills the second-order leveling accuracy requirement, and of 12mm√K in mountainous areas. 2. The sea surface topography (SST) values at one crossover of TOPEX/POSEIDON (near Bashi Channel) were computed using T/P cycles l to 183 data and the SST values were used to study the geostrophic currents at this crossover. In summer the currents flow northwards while in winter the currents flow southwards. The average speed is 41 to 50 cm/sec and the flow is in the northwest direction. 3. The geoid model and GPS ellipsoidal heights at 86 benchmarks measured in 1997 were used to compute modeled orthometric heights, which were compared with the orthometric heights measured 10 to 20 years ago. The differences show that almost all benchmarks undergo uplift in the past, mostly due to the collision between the Philippines Sea Plate and the Eurasia Plate.

碩士
世新大學
財務金融學研究所(含碩專班)
98
This paper employs the gravity model to investigate the determinants of international investment portofolios; the sample set contains five types of bilateral gross cross-border portfolio flows between 74 countries source and 237 host countries for 2001-2008 from the CPIS database. There are three main aspects of the model specification: cultural, socio-economic, financial structure; Consider the particular data, the five methods were used to estimate: pooling(OLS), fixed effect model, random effect model, two-stage estimation of Cheng and Wall (2005), and Hausman-Taylor model. In the past, plenty of literatures used the distance proxyed for stock market transaction cost; they found that distance and cross-border investment between the two countries have a negative correlation. However, considering the trade network concept with three types of network centrality index proposed by Freeman (1979) further. Network centrality indexes are “Degree Centrality”, “Closeness Centrality”, and “Betweenness Centrality”. It found that the coefficient of distance turns over from negative to positive when consider the degree of centrality, and greater links with the trade network, the more detrimental to bilateral investment; distance was no more significant efficiency affected by closeness centrality, and the larger of closeness centrality, the favorable for bilateral investment. Distance was no more significant efficiency affected by betweenness centrality, and it presents reaction the same with the degree centrality, the more links with the trade network, the more detrimental to bilateral investment.

In 2005-2006 in the framework of an INGV-DPC projects, in co-operation with the University of Rome “La Sapienza”, a gravity research started in the Colli Albani Volcanic District aimed: i) to realize a new gravity network to detect gravity changes due to mass redistribution in the underground inferred by the local volcanic activity; ii) to upgrade the already available Bouguer gravity map by means of new stations and to carry out new analyses and interpretations to outline a more detailed structural setting of the area. The gravity network has been designed so as to incorporate an old net of 7 stations, settled in 1981 by the same University group and periodically reoccupied until 2004. The new network is presently formed by 30 stations covering the whole volcanic area and all close to levelling benchmarks to remove the effect of the vertical ground movements. Taking into account the logistic situation of the area, three absolute gravity stations have been settled. Two of them have been located out of the volcanic area to be adopted as references (Sant'Angelo Romano and Palestrina). The third ones has been realized inside the most active part of the volcanic district to calibrate in future (Castel Gandolfo), through its repetition, the gravity changes detected by relative measurements. In the absolute sites the measurements of the vertical gravity gradient have been carried out because g is not directly measured on the ground. Each absolute station is completed with an external satellite ones, then included in the relative network, where the absolute value of g has been also transported through relative measurements. Moreover, 13 selected stations are also sites of vertical gravity gradient measurements. Those measurements helpful to reduce the effect of height changes on gravity variations and their space distribution is useful to reduce the prospecting gravity data. Four surveys of both relative and gradiometric measurements has been carried out (March and June 2006 - January and June 2007). In order to outline a more structural setting of the investigated area, a new set of about 900 new prospecting gravity stations have been settled inside an old survey made by 1500 stations measured partly by the Servizio Geologico d’Italia (SGI) in 1969 and partly by the University of Rome in 1995. Up today, the new stations have been partly measured and all the available data have been reprocessed and uniformed. The results from both the dynamics and the static gravimetry will be presented and discussed. 3-D density model of the Colli Albani Volcanic District was obtained. Based on its volcano-tectonic evolution, we interpret volcanic structures that have never been imaged before.
Dipartimento di Scienze della Terra Università Sapienza di Roma
Unpublished
1V. Storia eruttiva
2V. Struttura e sistema di alimentazione dei vulcani
4V. Dinamica dei processi pre-eruttivi
5V. Dinamica dei processi eruttivi e post-eruttivi
6V. Pericolosità vulcanica e contributi alla stima del rischio
2SR. VULCANI - Servizi e ricerca per la Società

碩士
世新大學
財務金融學研究所(含碩專班)
99
This paper employs the gravity model and Social Network Analysis to investigate the determinants of cross-border bank flow; the sample set contains bilateral gross cross-border bank flows between 24 countries source and 24 host countries for 1984-2009 from the Bank for International Settlements (BIS) database. Consider the particular data, the methods were used to estimate: fixed effect model, random effect model, and Hausman-Test model.In the past, plenty of literatures used the distance proxyed for stock market transaction cost; they found that distance and cross-border investment between the two countries have a negative correlation. However, considering the trade network concept with three types of network centrality index proposed by Freeman (1979) further. Network centrality indexes are “Degree Centrality”, “Closeness Centrality”, and “Betweenness Centrality”. And into the emotional investing, emotional investing with the country's GDP accounted for stock trading. The empirical results show: that the effect of distance by the emotional investment, distance and cross-border bank flows were positively correlated, and the emotional investment the higher will help cross-border bank flows; by the network centrality effects, in addition to betweenness centrality and cross-border bank flows were positively correlated, the other is negative correlated. And network- centrality of the higher (lower), cross-border bank flows higher (lower).

The Spin Foam models are a path integral picture of Loop Quantum Gravity approach to quantisation of gravitational field. This PhD thesis presents a study of four issues of Spin Foam models. The first problem addressed is the question of the class of 2-complexes, that ensure that Spin Foam models are compatible with the kinematic sector of Loop Quantum Gravity. A framework of diagrammatic representation of spin foams was developed while researching this issue. This diagramatic representation is called Operator Spin-network Diagrams (OSDs). The OSDs allow to express a spin foam as a collection of graphs, connected by certain relations. Each graph captures the local structure of one of spin foam vertices, i.e. nodes of a graph correspond to edges and links of a graph correspond to faces incident to a spin foam vertex. The relations between graphs in OSDs represent the way, in which edges and faces connect vertices. It is proven, that for each OSD there is an unambiguous way to construct a 2-complex with cells labelled by a spin foam coloring, so that one can calculate the spin foam transition amplitude. A clear procedure to glue OSDs along their boundaries was developed. Such gluing is an equivalent of composing quantum processes. All possible OSDs are characterised in terms of gluing of basic diagrams representing zero or one interaction vertex each. The proposition of the answer to the first question is that the appropriate class of 2-complexes for Spin Foam models is given by all the 2-complexes that can be obtained out of OSDs. The OSDs was applied to find a solution of so called boundary problem: to find all spin foams which have boundary given by certain initial and final states of Loop Quantum Gravity. An algorithm finding a series of all OSDs with a given fixed boundary is presented. The series is ordered by the number of internal edges of the corresponding spin foam. The algorithm is tested by applying it to Dipole Cosmology model (introduced in 2010 by E. Bianchi, C. Rovelli and F. Vidotto). All the diagrams contributing to Dipole Cosmology amplitude, which have the minimal number of internal edges, are found. The contribution to transition amplitude coming from these diagrams is studied. It appears that in this order of expansion all the diagrams except from one gives amplitudes that are exponentially suppressed in the semiclassical limit, thus their presence does not spoil the result of authors of Dipole Cosmology model. The third issue addressed in this thesis were the divergent amplitudes in Spin Foam models caused by bubbles in spin foam 2-complexes (i.e. subcomplexes forming closed surfaces). Within the framework of 2-complexes it is relatively hard to find the bubble part of a spin foam, whereas the framework of OSDs provides a simple procedure that unambiguously identifies the bubble subdiagram. A notion of the rank of a bubble is introduced. The rank counts the number of elementary bubbles that the considered bubble consist of. A method to calculate the rank for each given OSD is presented. Several simple cases of diagrams containing bubbles, that illustrate the algorithms, are presented and studied. The fourth question posed and answered within this thesis is related to detailed study of one particular case of a spin foam bubble, called melonic bubble. The melonic bubble is a spin foam analogue of self-energy renormalization in Quantum Field Theory. Recent research led to a conclusion, that in the first order the self-energy correction is proportional to some operator T, however the operator T was not known. In the thesis this operator is studied in semiclassical limit. After some elaborate calculations the exact form of the leading order of T is found: for fixed eigenvalues of the area operators it is proportional to the identity operator, with the proportionality constant dependent on the eigenvalues.
Piany spinowe (Spin Foams) są formalizmem całek po trajektoriach dla poszukiwań kwantyzacji pola grawitacyjnego w ramach Pętlowej Kwantowej Grawitacji (Loop Quantum Gravity, LQG). W tej rozprawie doktorskiej zostały przedstawione i rozwiązane cztery problemy modeli pian spinowych. Pierwszym przedstawionym zagadnieniem jest pytanie, na jakiej klasie 2-kompleksów należy zdefiniować modele pian spinowych, aby determinowana przez nie dynamika była określona dla wszystkich stanów kinematycznych LQG. W ramach badania tego zagadnienia wprowadzony został język diagramów, nazwanych diagramami operatorowo spin-networkowymi (Operator Spin-network Diagrams, diagramy OSD), pozwalający przedstawię pianę spinową jako zbiór grafów połączonych pewnymi relacjami. Każdy graf opisuje strukturę jednego wierzchołka piany spinowej: węzły grafu i połączenia węzłów grafu reprezentują odpowiednio krawędzie i ściany piany spinowej, stykające się z opisywanym wierzchołkiem. Relacje miedzy grafami w diagramach OSD opisują, w jaki sposób krawędzie i ściany łączą wierzchołki piany spinowej. Zostało udowodnione, że dla każdego diagramu OSD można w jednoznaczny sposób skonstruować 2-kompleks, którego komórki pokolorowane są tak, że można dla niego obliczyć pianową amplitudę przejścia. Ponadto wprowadzona została procedura sklejania diagramów OSD wzdłuż brzegów, odpowiadająca składaniu procesów kwantowych. Wszystkie możliwe diagramy OSD można przedstawić jako odpowiednie sklejenie diagramów elementarnych, tj. reprezentujących zero lub jeden wierzchołek oddziaływania. Wszystkie 2-kompleksy, które można uzyskać z diagramów OSD, tworzą klasę, która została zaproponowana jako adekwatna, aby zdefiniować na niej modele pian spinowych. Diagramy OSD zostały następnie użyte do rozwiązania tzw. problemu brzegowego, tzn. aby znaleźć wszystkie piany spinowe o z góry zadanym brzegu, składającym się z pary stanów - wejściowego i wyjściowego - będacych kinematycznymi stanami LQG. Sformułowany został algorytm pozwalający znaleźć szereg zawierający wszystkie diagramy OSD o określonym brzegu. Diagramy te uszeregowane są względem liczby wewnętrznych krawędzi odpowiadających im pian spinowych. Algorytm ten został przetestowany na modelu Dipole Cosmology (wprowadzonym w 2010 przez E. Bianchi, C. Rovelli oraz F. Vidotto). Znalezione zostały wszystkie diagramy dające wkład do amplitudy przejścia w modelu Dipole Cosmology w najniższym rzędzie. Zbadany został również wkład znalezionych diagramów do amplitudy. Okazało się, że amplitudy wszystkich znalezionych zanikają eksponencjalnie w granicy semiklasycznej, tak więc uwzględnienie ich nie psuje wyników autorów modelu Dipole Cosmology. Trzecim zagadnieniem badanym w ramach niniejszej rozprawy są nieskończoności występujące w pianach spinowych wywołane obecnością bąbli w 2-kompleksach (tzn. podkompleksów tworzących zamknięte powierzchnie). W ramach dotychczasowego języka opartego na 2-kompleksach znajdywanie bąbli było uciążliwe. Dzięki diagramom OSD wprowadzony został prosty algorytm pozwalający jednoznacznie zidentyfikować część diagramu reprezentującą bąbel. Wprowadzone zostało pojecie rzędu bąbla, mierzące liczbę elementarnych bąbli składających się na badany bąbel. Podana została metoda obliczenia rzędu bąbla dla dowolnego diagramu OSD. Powyższe narzędzia zostały zilustrowane przykładami prezentującymi kilka podstawowych typów bąbli. Czwarte pytanie, na które odpowiedź zawarta jest w tej rozprawie, związane jest ze szczegółową analizą konkretnego przykładu bąbla, zwanego bąblem typu melon. Bąbel typu melon jest pianą spinową reprezentującą proces analogiczny do energii samooddziaływania w Kwantowej Teorii Pola. Dotychczasowe badania pokazały, że jego amplituda jest proporcjonalna do pewnego operatora T, jednak sam operator T był nieznany. W ramach niniejszej rozprawy doktorskiej operator T został zbadany w granicy semiklasycznej. Uzyskano ścisłą postać wiodącego rzędu operatora T: dla ustalonych wartości własnych operatorów pola powierzchni jest on proporcjonalny do operatora jednostkowego ze współczynnikiem proporcjonalności zależnym od tych wartości własnych.

碩士
國立交通大學
交通運輸研究所
86
The Gravity-type Interactive Markov models(GIM models) were introduced by Smith and Hsieh in 1994,in which migration flows in each time period are postulated to vary directly with some population-dependent measure of attractiveness and inversely with some symmetric measure of migration costs. From the viewpoint of theoretical analysis, the choice behavior of individuals inGIM models is similar to that of drivers in selecting routes in logit-based stochastic traffic assignment problems. This study is trying to formulate the GIM model of the stochastic traffic assignment in a road network. The followings will be the goal of this study: (1). Prove that the steady-state conditions of the GIM model is equivalent to the stochastic user equilibrium (SUE) conditions of the problems.(2).Develop a new algorithm for solving the SUE of the problems.(3).Compare the GIM algorithm with exiting algorithm, e.g. Frank-Wolfe method, MSA.(4).Analyze the convergence to the SUE of the GIM algorithm. This method has implemented by Mathmatica. The computation of different algorithms on different examples shows that the adjustment ratio have a great influence on the speed of convergence. And the level of overlapping in the network is slight, we can solve the stochastic user equilibrium problems that haveoverlapping links in the network by GIM algorithm.

Tese de doutoramento em Território, Risco e Políticas Públicas, apresentada ao Instituto de Investigação Interdisciplinar da Universidade de Coimbra
For several decades critical infrastructure management belonged to engineering domains; however a new paradigm has emerged - socio-technical paradigm - infrastructures are critical because they have value for society and for a culture. Thus, critical infrastructure operate not only according to technical specifications but also according to constraints imposed by the social environment. The problem is how to integrate in the same model the linkages between infrastructure and social systems. The main goal of this thesis is to propose a new model the Structural Functional Risk Model – SFRM- a model that identifies the roads more vulnerable to interruptions, based on an integrated approach of the structural and functional component of the road network- a critical infrastructure responsible for connecting people, assets and services separated in space. The model is applied to real road network in a multiscalar perspective, the regional context and the municipal context. The case studies are the Central Region of Portugal and Coimbra, a municipality located in this Region. The system used as example focus the road network as element of connection and access between the parishes and the nearest Hospital – a critical infrastructure of the health sector. The methodological approach is composed by three main phases: firstly, the road network is assessed in a structural perspective based on the application of a new approach of the biclustering technique; the following phase is focused on the evaluation of the road network in a functional perspective based on a modified gravity model; the last phase is focused on the integration of structural and functional perspective, which resulted the SFRM. Scenario- based approaches are also relevant in this work, focusing questions such: what can happen? If it does happen, what are the consequences? A scenario-based approach can be a useful support to a more informed, strategic action. Thus, through the work there will be simulated and analyzed road interruption scenarios. The results confirmed the importance of an integrated approach of the structural and functional components. In the assessment of the road network structural component the results pointed that the Biclusters with highest connectivity are mainly located in the II areas economically most dynamic, such the Coastal zone, and the Biclusters with lowest connectivity are mainly located in areas less dynamic, such Beira Transmontana. So, even when the analysis is focused on a network transformed into nodes and edges it is possible to identify relations with the territorial dynamics. The results of the road network functional component assessment point to a significant resources concentration in Coimbra municipality; in the regional context identified significant accessibility gaps across geographical areas and population groups; even in a normal scenario there are significant disparities in terms of accessibility to health care, which can get worse in a road network interruption scenario. From the integration of the structural and functional component of the road network resulted the SFRM, which is a step forward; quantifying the share of accountability of each of the components in the road level of vulnerability. The results demonstrate that territorial constraints play a fundamental role in critical infrastructure management; the strategies set in this domain should take into account the specificities of each territory and population characteristics. This thesis can be seen as step forward in the consolidation of the socio-technical paradigm as well as a tool for the definition of efficient of prevention measures and the definition of strategies aiming quick recovery of the system in case of a disruptive event.
Durante várias décadas a gestão das infra-estruturas críticas pertenceu ao domínio da engenharia; contudo surgiu um novo paradigma – o paradigma socio-técnico – as infraestruturas são críticas pelo valor que representam para a sociedade e para a cultura. Neste sentido, o funcionamento das infra-estruturas críticas depende não só de especificidades técnicas, mas também é condicionado pelo meio social. O problema reside em saber como integrar no mesmo modelo as ligações existentes entre as infraestruturas e os sistemas sociais. O principal objetivo deste trabalho é propor um novo modelo - Modelo de Risco Estrutural e Funcional – MREF- que identifica as vias mais vulneráveis a interrupções, numa abordagem integrada da componente estrutural e funcional da rede viária – uma infra-estrutura crítica que tem como função ligar pessoas, bens e serviços separados no espaço. O MRFE é aplicado a uma rede viária real numa perspetiva multiescalar, os casos de estudo são a Região Centro de Portugal e Coimbra, um município localizado nesta Região. O sistema de análise, usado como exemplo, focase na rede viária como elemento de ligação e acesso entre as freguesias e os Hospitais – importantes infra-estruturas críticas do sector da saúde. A metodologia usada neste trabalho é constituída por três fases: numa primeira fase a rede viária é avaliada sob o ponto de vista estrutural com base numa nova abordagem da técnica de biclustering; a fase seguinte foca-se na avaliação da rede viária sob o ponto de vista funcional com base num modelo gravitacional adaptado aos objetivos do presente trabalho; a última fase foca-se na integração da avaliação estrutural com a funcional da qual resulta o MRFE. As abordagens com base em cenários também assumem relevância neste trabalho, focando questões como: O que pode acontecer? Caso aconteça, quais são as consequências? Os resultados desta abordagem contribuem para ação mais informada e estratégica. Neste sentido, ao longo do trabalho serão apresentados e avaliados vários cenários de interrupção de vias. Os resultados demonstram a importância de uma abordagem integrada da componente funcional e da estrutural. Aquando da avaliação da rede viária sob o ponto de vista estrutural os resultados indicaram que os biclusters com maior nível de conectividade se IV encontram essencialmente localizados nas áreas economicamente mais dinâmicas – como a zona costeira, enquanto os biclusters com menor nível de conectividade se encontram essencialmente localizados nas áreas economicamente mais deprimidas – como a Beira Transmontana. Conclui-se que mesmo quando a análise se foca na rede viária enquanto conjunto de nós e ligações é possível identificar relações com a dinâmica territorial. Os resultados da avaliação da rede viária sob o ponto de vista funcional indicam uma significativa polarização de recursos no município de Coimbra, no contexto regional foram identificadas expressivas diferenças em termos de áreas geográficas e grupos populacionais; estas significativas disparidades poderão ser agravadas num cenário de interrupção de vias. O MREF resulta de uma abordagem integrada das componentes estruturais e funcionais da rede viária, um modelo que pode ser visto como um passo em frente uma vez que são definidas e quantificadas as variáveis que influenciam a vulnerabilidade da rede viária. Os resultados demonstram que as condicionantes territoriais devem constituir uma componente fundamental na gestão das infra-estruturas críticas; as estratégias definidas neste âmbito devem ter em atenção as especificidades do território e as características da população. O presente trabalho pode ser visto como contributo para a consolidação do paradigma sociotécnico assim como um instrumento para a definição de medidas de prevenção eficientes e definição de estratégias que tenham em vista o rápido restabelecimento do funcionamento do sistema num cenário disruptivo.
Fundação para a Ciência e Tecnologia - SFRH/BD/70952/2010

Relatório de Projecto
Neste projecto estudou-se a actual rede de fluxos da DHL Exel Supply Chain Portugal, bem como as oportunidades de ganhos de eficiência através do seu redesenho, tendo por base de análise, a rede multi-cliente do sector de clientes de Consumo e Retalho da referida empresa. A optimização do redesenho da rede da DHL Exel Supply Chain Portugal teve como principal preocupação dar resposta a um problema real da empresa, conseguindo encontrar uma solução mais eficiente para diminuir custos de transporte, ou seja, diminuir os custos associados ao tipo de frota utilizada pela empresa. O redesenho da rede depende de um conjunto de variáveis incluindo os fluxos físicos que se verificam na base de análise, bem como dos modelos de exploração de veículos utilizados no transporte de carga. Após o estudo realizado, concluiu-se que há necessidade de criar uma nova plataforma logística, devido aos elevados fluxos físicos em determinados pontos do país. A localização da nova plataforma logística a implementar, foi conseguida através da aplicação do Modelo Gravítico, onde o output deste se reflecte em coordenadas que indicarão um ponto geograficamente específico no mapa de Portugal Continental. O redesenho da rede resultou na introdução de uma plataforma logística na zona Norte do país.
This project studies the present network of DHL Exel Supply Chain Portugal, seeking for opportunities to increase efficiency through a network redesign. The network in analysis is the multi-client network of industrial and retail customers. The optimization of the redesign of the network of DHL Exel Supply Chain Portugal main concern was to address the real problem of the company, achieving a solution more efficient to reduce transportation costs, or reduce costs associated with the type used by the fleet company. The network redesign depends on a number of variables, including the physical flows that occur and the type of vehicles used for transporting cargo. This study concludes that there is a need to create a new logistics platform, due to high physical flows in certain parts of the country. The location of the new logistics platform had been achieved through the implementation of the Center of Gravity Approach, where the output of this is reflected in a coordinate that indicate a specific geographic point on the map of Portugal. The redesign of the network resulted in the introduction of a logistics platform in the north of the country.

The objective of this dissertation is to investigate the factors that influence the design of wide-area wavelength division multiplexing (WDM) optical networks. Wide-area networks are presented as communication networks capable of transporting voice and data communication over large geographical areas. These networks typically span a whole country, region or even continent.The rapid development and maturation of WDM technology over the last decade have been well-received commercially and warrants the development of skills in the field of optical network design.The fundamental purpose of all communication networks and technologies is to satisfy the demand of end-users through the provisioning of capacity over shared and limited physical infrastructure. Consideration of the business aspects related to communications traffic and the grooming thereof are crucial to developing an understanding of customer requirements in terms of the selection and quality of services and applications. Extensive communication networks require complex management techniques that aim to ensure high levels of reliability and revenue generation.An integrated methodology is presented for the design of wide-area WDM optical networks. The methodology harnesses physical, logical, and virtual topologies together with routing and channel assignment (RCA) and clustering processes to enhance objectivity of the design process. A novel approach, based on statistical clustering using the Ward linkage as similarity metric, is introduced for solving the problem of determining the number and positions of the backbone nodes of a wide-area network, otherwise defined as the top level hub nodes of the multi-level network model. The influence of the geographic distribution of network traffic, and the intra/inter-cluster traffic ratios are taken into consideration through utilisation of modified gravity models and novel network node weighting.
Dissertation (MEng)--University of Pretoria, 2005.
Electrical, Electronic and Computer Engineering
unrestricted

碩士
淡江大學
資訊工程學系資訊網路與通訊碩士班
100
The advancement of technology changes with each day. In recent years, it extends many different types of wireless network. Wireless sensor networks become a hot issue in research. Wireless sensor networks are composed of multiple sensor nodes that are randomly deployed. Each sensor node has sensing and computing capability to sense different environments according to different applications and transmit these data to sink. However, how to reduce energy consumption in the transmission process is important research. In this thesis, we propose a Tree-based Data Aggregation Mechanism using Center of Gravity (TDCoG). Initially, it builds transmission paths of tree structure, and then does data aggregation. This mechanism may solve the hot spot problem and achieve the effect that loading balancing of energy and extending the lifetime of the network.

This thesis studies the dynamics of the Loop Quantum Gravity states defined by the spin-foam models of Euclidean 4D Quantum Gravity. A link between the 4D spin-foam theory and the kinematics of the (3+1) Loop Quantum Gravity (LQG) was proposed by J. Engle, R. Pereira, C. Rovelli and E. Livine. Their model, called the EPRL spin-foam model, is a promising candidate for the spin-foam model of the dynamics of the Loop Quantum Gravity states. In the original formulation, the EPRL spin-foam model is defined for triangulations and is applicable to specific LQG states. A generalization of the model to all the LQG states was proposed by W. Kamiński, J. Lewandowski and myself. Some properties of the generalized model were studied. In particular, a general framework for studying symmetries of spin-foam models was proposed. The heart of the generalization is the generalized EPRL vertex amplitude. E. Bianchi, D. Regoli and C. Rovelli proposed another spin-foam model of 4D Quantum Gravity with the generalized EPRL vertex amplitude. E. Bianchi, C. Rovelli and F. Vidotto used the generalized EPRL spin-foam model to construct the first model of Quantum Cosmology based on the spin-foam formalism. They calculated a transition amplitude between coherent states peaked on homogeneous, isotropic geometries using certain approximations. The approximations were justified a posteriori by a correct semiclassical limit of the transition amplitude. One of them was a truncation of the transition amplitude to a contribution from a single foam with one internal vertex, four internal edges and a certain boundary, which we will call a BRV foam. F. Hellmann discussed contributions from other foams with these properties, which a priori cannot be discarded. All the possible foams were listed by J. Lewandowski, J. Puchta and myself. The class of the foams considered was defined by graph diagrams, which we introduced. We expect that the contributions from the foams we have found can be neglected in the limit of large universe.
Przedmiotem badań prezentowych w mojej rozprawie doktorskiej jest dynamika stanów pętlowej kwantowej grawitacji zdefiniowana przez pianowo-spinowe modele euklidesowej czterowymiarowej kwantowej grawitacji. Związek pomiędzy czterowymiarowymi teoriami pian spinowych a kinematyką pętlowej kwantowej grawitacji został zaproponowany przez J. Engle’a, R. Pereirę, C. Rovelliego i E. Livine’a. Ich model, nazywany modelem EPRL, jest dobrze zapowiadającym się kandydatem na pianowo-spinowy model dynamiki stanów pętlowej kwantowej grawitacji. W pierwotnym sformułowaniu model EPRL jest zdefiniowany dla triangulacji czasoprzestrzeni i może być stosowany tylko dla pewnych stanów pętlowej kwantowej grawitacji. Uogólnienie modelu do wszystkich stanów zostało zaproponowane przez J. Lewandowskiego, W. Kamińskiego i przeze mnie. Pewne własności uogólnionego modelu zostały zbadane. W szczególności została zaproponowana ogólna metoda badania symetrii modeli pian spinowych. Głównym elementem zaproponowanego uogólnienia jest uogólniona amplituda wierzchołka EPRL. E. Bianchi, D. Regoli i C. Rovelli zaproponowali inny pianowo-spinowy model czterowymiarowej kwantowej grawitacji z uogólnioną amplitudą wierzchołka EPRL. E. Bianchi, C. Rovelli i F. Vidotto zastosowali model w celu skonstruowania pierwszego modelu kwantowej kosmologii opartego na formalizmie pian spinowych. Stosując pewne przybliżenia, obliczyli amplitudę przejścia pomiędzy stanami koherentnymi, skupionymi na jednorodnych, izotropowych geometriach. Zastosowane przybliżenia były uzasadnione a posteriori poprzez poprawną granicę semi-klasyczną amplitudy przejścia. Jednym z zastosowanych przybliżeń było obcięcie amplitudy przejścia do wkładu pochodzącego od jednej piany mającej jeden wierzchołek wewnętrzny, cztery wewnętrzne krawędzie i pewien brzeg, którą będziemy nazywać pianą BRV. F. Hellmann przedyskutował wkłady od innych pian, które nie mogą zostać odrzucone a priori. Wszystkie możliwe piany z tymi własnościami zostały znalezione przez J. Lewandowskiego, J. Puchtę i przeze mnie. Klasa rozważanych pian została zdefiniowana przez wprowadzone przez nas diagramy grafowe. Spodziewamy się, że wkłady od znalezionych pian mogą zostać zaniedbane w granicy dużych rozmiarów wszechświata.

碩士
國立臺北大學
經濟學系
99
Recalling the history of Taiwan's economic development, since the middle period of 1980 times, as the NT dollar appreciate and a substantial increase in labor costs, the products of labor-intensive produced from Taiwan's manufacturers have gradually lost international competitiveness. At the same time, because of the NT dollar appreciation, it is advantageous for our manufacturers invest abroad. Therefore, the first wave of foreign direct investment would start. In recent years, because of technological development and globalization, making the trade between countries around the world more closer .In the past paper of concerning on the main factor of a country’s FDI, almost use the home country’s export to be explanatory variable ,but the analysis only could observe the relationship between the home country’s export and FDI, could not observe how the influence from the host country’s trade openness and position in trade networks bring to home country. Therefore ,this paper wants to use trade network analysis to explore the host country’s trade openness and role in the global trade networks bring what impact on the Taiwan’s firm to FDI . Our study used gravity model to explore the determinant factor of Taiwan’s FDI during 1992 to 2006. With random effects for the panel data, we classified the host countries to three parts according to they are economic status. The host countries would to be respectively all countries, high- income countries and low-income countries .Our research is not only put the variable that gravity model use, but also add trade network indicators to the paper. We want to focus on whether the trade network indicators of host countries bring impact on Taiwan’s FDI. And we have some important conclusions. First, we find that GDP and per GDP have positive signs for FDI , but the distance do not. Secondly, the host country’s indegree, outdegree and closeness have negative signs for FDI. Thirdly, FDI and the host country’s betweenness have a positive relation, except for all countries.

碩士
世新大學
財務金融學研究所(含碩專班)
99
In recent years, a substantial increase in international migration of population. According to the latest statistical data of DESA (United Nations Department of Economic and Social Affairs), it will increase to more 200 million people that were the total number of the world population of 3.1% in 2010. Total fertility rate of Taiwan is 1.03% that was the last ranking of the world in 2009. Taiwan could refer to foreign experience “international migration”, and it an important strategy to solve the population problem. Before attract the international immigration, this study analyze the determinant factor driver of global migration. This research use global bilateral migration data of 226 countries and 51076 samples. Also use the indicators of communications networks to demonstrate international migration by gravity model and measure determinant factors of international migration. Base on the theory and model of the Population Econometrics, this study examine the determinant factors of international population migration by the gravity model. Also, this research use social networks analysis to examine the positive and negative determinant factors of international population movement. The results indicate that the geographical and cultural factors, social and economic factors, and international trade factors with the application of gravity model and social networks analysis are significant impact on the international population migration. In the application of social networks analysis, trade centre networks and communications networks of the indicators in the global population migration play an important role.

碩士
世新大學
財務金融學研究所(含碩專班)
100
The United States has always been the growth engine of the world economy until the financial crisis. Global economy of the great depression, the major importing countries, imports have fallen sharply. Since America is the epicenter of the financial crisis, however, private domestic absorption in the U.S. is falling rapidly. It is questionable whether the U.S. can continue to play the same role in the future. This paper considers whether East Asia could function as an engine of growth. After three years later, Japan, Britain, Germany, the euro zone, China, the United States imports begun to resume growth, but growing up is very different. The imports of consumption data from all countries indicate that income increases in East Asian countries would cause large increases in imports. Study the eight countries of East Asia were China, Indonesia, Japan, South Korea, Malaysia, the Philippines, Taiwan and Thailand data on consumption imports as explained variables and empirical analysis from 173 countries. The data set extends from 2005 to 2009. Using the least squares method to do the estimated analysis. The results indicate that an increase in income in East Asia would produce a large increase in imports. The evidence also implies that an RMB appreciation would raise China’s imports. Thus, if East Asia can success implementation of domestic demand-led growth strategy, and will stimulate economic growth all over the world.

碩士
國立交通大學
資訊科學與工程研究所
99
Deploying body-area inertial sensor networks on human bodies to capture motions has attracted a lot of interests recently, especially in cyber-physical video games and context aware applications. While video games on the cyber world have been quite popular, enhancing them with more physical inputs, such as those from inertial sensors, is becoming a new trend. Following this trend, we develop a video game integrated with body-area inertial sensor networks deployed on players as inputs and with multiple game screens to broaden players’ views and provide more realistic interaction experiences. Our design simulates a multi-screen game engine by controlling a set of game engines simultaneously. A prototype with a body-area inertial sensor network platform, a cyber-physical game controller, and a set of game engines is demonstrated. The demonstrated game also addresses the interaction between virtual objects and players. Tracking human posture system based on accelerometer. One fundamental issue in such scenarios is how to calculate the gravity, no matter when human body parts are moving or not. Assuming multiple accelerometers being deployed on a rigid part of a human body, a recent work proposes a data fusion method to estimate the gravity on that rigid part. However, how to find the optimal deployment of sensors that minimizes the estimation error of the gravity is still an open problem. In this paper, we formulate the deployment optimization problem, present deployment guidelines, and propose some heuristics, including a virtual-force-based (VF-based) method and a Metropolis-based search method. Experimental results are presented to verify our results.

The thesis explores the question of whether immigrants can spur the internationalization and innovation activities of the local production systems of their countries of destination. It is composed of two parts. In the first part, migrants' pro-trade effects is analysed through a theory-consistent gravity model augmented with migration variables. The analysis takes subnational units, i.e. NUTS3 regions, and compares Italy and Spain. The empirical model allows for subnationally heterogeneous multilateral resistance term. An econometric strategy based on Head and Mayer (2014) is implemented to address the main econometric issues and to select the suitable estimator. This leads to selecting the Gamma PML estimator in the case of Spain and the OLS estimator in the Italian case. The results suggest that applying the same model to different contexts can lead to different results: immigration is found to have a positive trade facilitating effect in the Spanish case and a negative trade-diverting role in the Italian case. This difference is attributed to specificities in the composition and integration patterns of the immigrant population in the two countries; tentative explanations are proposed for the negative effect. The second part of the thesis analyses the determinants of immigrants’ employment focussing, in a comparative perspective, on two case studies of local systems specialized in the mechanic sector, i.e. Reggio Emilia in Italy and Elgoibar in Spain. The two are similar in many respects - income and employment levels, sectoral specialisation, high levels of local social capital - but are marked by quite different capacity of integrating immigrant labour in the core industry. Drawing on the availability of two sets of similar firm-level microdata at the corresponding NUTS2 levels, cluster and discriminant analysis are performed to outline the characteristics of firms hiring immigrants in each context. The comparison of the two regions shows that, in the more inclusive context, immigrants are also much more frequently employed in knowledge-oriented firms. The subjective determinants for hiring immigrants are deepened in a series of semi-structured interviews with the employers. In the local system marked by bridging social capital, immigrants’ employment is found to be determined by a wider set of considerations that span well beyond labour replacement in manual tasks. Diverse work teams are reported to contribute to product development and innovation allowing a combination of cost-saving standardization and cultural-specific customizability to serve foreign tastes.