Techniques for distributed theory synthesis in multiagent systems

Data sources are often dispersed geographically in real life applications. Finding a knowledge model may require to join all the data sources and to run a machine learning algorithm on the joint set. We present an alternative based on a Multi Agent System (MAS): an agent mines one data source in order to extract a local theory (knowledge model) and then merges it with the previous MAS theory using a knowledge fusion technique. This way, we obtain a global theory that summarizes the distributed knowledge without spending resources and time in joining data sources. New experiments have been executed including statistical significance analysis. The results show that, as a result of knowledge fusion, the accuracy of initial theories is significantly improved as well as the accuracy of the monolithic solution.

Exploring the potential of novel biomixtures and Lentinula edodes fungus for the degradation of selected pesticides. Evaluation for use in biobed systems

An approach to reduce the contamination of water sourceswith pesticides is the use of biopurificaction systems. The active core of these systems is the biomixture. The composition of biomixtures depends on the availability of local agro-industrial wastes and design should be adapted to every region. In Portugal, cork processing is generally regarded as environmentally friendly and would be interesting to find applications for its industry residues. In this work the potential use of different substrates in biomixtures, as cork (CBX); cork and straw, coat pine and LECA (Light Expanded Clay Aggregates), was tested on the degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin pesticides. Bioaugmentation strategies using the white-rot fungus Lentinula edodes inoculated into the CBX, was also assessed. The results obtained from this study clearly demonstrated the relevance of using natural biosorbents as cork residues to increase the capacity of pesticide dissipation in biomixtures for establishing biobeds. Furthermore, higher degradation of all the pesticides was achieved by use of bioaugmented biomixtures. Indeed, the biomixtures inoculated with L. edodes EL1were able to mineralize the selected xenobiotics, revelling that these white-rot fungi might be a suitable fungus for being used as inoculum sources in on-farm sustainable biopurification system, in order to increase its degradation efficiency. After 120 days, maximum degradation of terbuthylazine, difenoconazole, diflufenican and pendimethalin, of bioaugmented CBX, was 89.9%, 75.0%, 65.0% and 99.4%, respectively. The dominant metabolic route of terbuthylazine in biomixtures inoculated with L. edodes EL1 proceeded mainly via hydroxylation, towards production of terbuthylazine-hydroxy-2 metabolite. Finally, sorption process to cork by pesticides proved to be a reversible process,working cork as a mitigating factor reducing the toxicity to microorganisms in the biomixture, especially in the early stages.

Advances in integration of photovoltaic power and energy production in practical systems

This thesis presents advances in integration of photovoltaic (PV) power and energy in practical systems, such as existing power plants in buildings or directly integrated in the public electrical grid. It starts by providing an analyze of the current state of PV power and some of its limitations. The work done in this thesis begins by providing a model to compute mutual shading in large PV plants, and after provides a study of the integration of a PV plant in a biogas power plant. The remainder sections focus on the work done for project PVCROPS, which consisted on the construction and operation of two prototypes composed of a PV system and a novel battery connected to a building and to the public electrical grid. These prototypes were then used to test energy management strategies and validate the suitability of the two advanced batteries (a lithium-ion battery and a vanadium redox ow battery) for households (BIPV) and PV plants. This thesis is divided in 7 chapters: Chapter 1 provides an introduction to explain and develop the main research questions studied for this thesis; Chapter 2 presents the development of a ray-tracing model to compute shading in large PV elds (with or without trackers); Chapter 3 shows the simulation of hybridizing a biogas plant with a PV plant, using biogas as energy storage; Chapters 4 and 5 present the construction, programming, and initial operation of both prototypes (Chapter 4), EMS testing oriented to BIPV systems (Chapter 5). Finally, Chapters 6 provides some future lines of investigation that can follow this thesis, and Chapter 7 shows a synopsis of the main conclusions of this work; Resumo: Avanços na integracão de potência fotovoltaica e producão de energia em sistemas práticos Esta tese apresenta avanços na integração de potência e energia fotovoltaica (PV) em sistemas práticos, tais como centrais existentes ou a rede eléctrica pública. Come ça por analisar o estado corrente do fotovoltaico no mundo e aborda algumas das suas limitações. O trabalho feito para esta tese de doutoramento começou pelo desenvolvimento de um modelo para calcular os sombreamentos que ocorrem em grandes campos fotovoltaicos, e depois apresenta um estudo sobre a integração um sistema fotovoltaico em uma central eléctrica a bióg as. As ultimas secções da tese focam-se no trabalho feito para o projecto PVCROPS, que consistiu na construção e operação de dois demonstratores, cada um formado por um sistema fotovoltaico e bateria conectados a um edíficio e a rede eléctrica pública. Estes protótipos foram posteriormente utilizados para testar estratégias de gestão de energia (EMS) e para validar a operação de duas baterias avançadas (bateria de Iões de Li tio e bateria de Fluxo Redox de Van adio) e a sua utiliza ção para habitações e centrais PV. A tese está dividida em 7 capitulos: O capitulo 1 apresenta uma introdução para explicar e desenvolver as principais questões que foram investigadas nesta tese; O capitulo 2 mostra o desenvolvimento de um modelo baseado em traçados de raios para calcular sombreamentos mútuos em grandes centrais PV (com e sem seguidores); O capitulo 3 mostra a simulação da hibridização de uma central electrica a biogas com uma central PV, e utilizando o biógas como armazenamento de energia. Os capitulos 4 e 5 apresentam a construção, programação e operação inicial dos dois demonstradores (Capitúlo 4), o teste de EMS orientadas para sistemas PV em habitações (Capítulo 5). Finalmente, o capítulo 6 sugere algumas futuras linhas de investigação que poderão seguir esta tese, e o Capítulo 7 faz uma sinopse das principais conclusões deste trabalho.

Forage dry mass accumulation and structural characteristics of Piatã grass in silvopastoral systems in the Brazilian savannah

2016

Agronomic, morphogenic and structural characteristics of Marandu grass in silvopastoral systems composed of babassu palm and grass monoculture.

This study evaluated the agronomic, morphogenic and structural characteristics of palisadegrass (Urochloa brizantha) in silvopastoral systems (SSP?s) composed of babassu palms (Attalea speciosa) and grass monoculture in the Pre-Amazon region of the state of Maranhão, Brazil. The study followed a completely randomized design, with the arrangement in split plots with six replicates for the evaluation of agronomic characteristics and 30 repetitions for the morphogenic and structural characteristics. The plots were divided into pasture environments with different palm densities (monoculture, 80, 131, 160 palms.ha-¹), and the subplots were divided into the different seasons (rainy and dry).

Unified control system for three-phase electric drives operating in magnetic saturation region

The research project aims to study and develop control techniques for a generalized three-phase and multi-phase electric drive able to efficiently manage most of the drive types available for traction application. The generalized approach is expanded to both linear and non- linear machines in magnetic saturation region starting from experimental flux characterization and applying the general inductance definition. The algorithm is able to manage fragmented drives powered from different batteries or energy sources and will be able to ensure operability even in case of faults in parts of the system. The algorithm was tested using model-in-the-loop in software environment and then applied on experimental test benches with collaboration of an external company.

Multi-Principal Agency and the Compliance with Professional Guidelines in Health Systems: Economic and Regulatory Perspectives

Amid the trend of rising health expenditure in developed economies, changing the healthcare delivery models is an important point of action for service regulators to contain this trend. Such a change is mostly induced by either financial incentives or regulatory tools issued by the regulators and targeting service providers and patients. This creates a tripartite interaction between service regulators, professionals, and patients that manifests a multi-principal agent relationship, in which professionals are agents to two principals: regulators and patients. This thesis is concerned with such a multi-principal agent relationship in healthcare and attempts to investigate the determinants of the (non-)compliance to regulatory tools in light of this tripartite relationship. In addition, the thesis provides insights into the different institutional, economic, and regulatory settings, which govern the multi-principal agent relationship in healthcare in different countries. Furthermore, the thesis provides and empirically tests a conceptual framework of the possible determinants of (non-)compliance by physicians to regulatory tools issued by the regulator. The main findings of the thesis are first, in a multi-principal agent setting, the utilization of financial incentives to align the objectives of professionals and the regulator is important but not the only solution. This finding is based on the heterogeneity in the financial incentives provided to professionals in different health markets, which does not provide a one-size-fits-all model of financial incentives to influence clinical decisions. Second, soft law tools as clinical practice guidelines (CPGs) are important tools to mitigate the problems of the multi-principal agent setting in health markets as they reduce information asymmetries while preserving the autonomy of professionals. Third, CPGs are complex and heterogeneous and so are the determinants of (non-)compliance to them. Fourth, CPGs work but under conditions. Factors such as intra-professional competition between service providers or practitioners might lead to non-compliance to CPGs – if CPGs are likely to reduce the professional’s utility. Finally, different degrees of soft law mandate have different effects on providers’ compliance. Generally, the stronger the mandate, the stronger the compliance, however, even with a strong mandate, drivers such as intra-professional competition and co-management of patients by different professionals affected the (non-)compliance.

Development of a Whole-Genome Sequencing (WGS) approach for the characterization of Legionella environmental isolates in water systems

Legionella is a Gram-negative bacterium that represent a public health issue, with heavy social and economic impact. Therefore, it is mandatory to provide a proper environmental surveillance and risk assessment plan to perform Legionella control in water distribution systems in hospital and community buildings. The thesis joins several methodologies in a unique workflow applied for the identification of non-pneumophila Legionella species (n-pL), starting from standard methods as culture and gene sequencing (mip and rpoB), and passing through innovative approaches as MALDI-TOF MS technique and whole genome sequencing (WGS). The results obtained, were compared to identify the Legionella isolates, and lead to four presumptive novel Legionella species identification. One of these four new isolates was characterized and recognized at taxonomy level with the name of Legionella bononiensis (the 64th Legionella species). The workflow applied in this thesis, help to increase the knowledge of Legionella environmental species, improving the description of the environment itself and the events that promote the growth of Legionella in their ecological niche. The correct identification and characterization of the isolates permit to prevent their spread in man-made environment and contain the occurrence of cases, clusters, or outbreaks. Therefore, the experimental work undertaken, could support the preventive measures during environmental and clinical surveillance, improving the study of species often underestimated or still unknown.

Early-stage deformation localisation in thrust systems: new perspectives from carbonates in the Italian Southern Alps and Oman Mountains

This thesis investigates mechanisms and boundary conditions that steer the early localisation of deformation and strain in carbonate multilayers involved in thrust systems, under shallow and mid-crustal conditions. Much is already understood about deformation localisation, but some key points remain loosely constrained. They encompass i) the understanding of which structural domains can preserve evidence of early stages of tectonic shortening, ii) the recognition of which mechanisms assist deformation during these stages and iii) the identification of parameters that actually steer the beginning of localisation. To clarify these points, the thesis presents the results of an integrated, multiscale and multi-technique structural study that relied on field and laboratory data to analyse the structural, architectural, mineralogical and geochemical features that govern deformation during compressional tectonics. By focusing on two case studies, the Eastern Southern Alps (northern Italy), where deformation is mainly brittle, and the Oman Mountains (northeastern Oman), where ductile deformation dominates, the thesis shows that the deformation localisation is steered by several mechanisms that mutually interact at different stages during compression. At shallow crustal conditions, derived conceptual and numerical models show that both inherited (e.g., stratigraphic) and acquired (e.g., structural) features play a key role in steering deformation and differentiating the seismic behaviour of the multilayer succession. At the same time, at deeper crustal conditions, strain localises in narrow domains in which fluids, temperature, shear strain and pressure act together during the development of the internal fabric and the chemical composition of mylonitic shear zones, in which localisation took place under high-pressure (HP) and low-temperature (LT) conditions. In particular, results indicate that those shear zones acted as “sheltering structural capsules” in which peculiar processes can happen and where the results of these processes can be successively preserved even over hundreds of millions of years.

Analysis and development of interface components and procedures for the design and commissioning toolchains in automation systems

The objective of the thesis project, developed within the Line Control & Software Engineering team of G.D company, is to analyze and identify the appropriate tool to automate the HW configuration process using Beckhoff technologies by importing data from an ECAD tool. This would save a great deal of time, since the I/O topology created as part of the electrical planning is presently imported manually in the related SW project of the machine. Moreover, a manual import is more error-prone because of human mistake than an automatic configuration tool. First, an introduction about TwinCAT 3, EtherCAT and Automation Interface is provided; then, it is analyzed the official Beckhoff tool, XCAD Interface, and the requirements on the electrical planning to use it: the interface is realized by means of the AutomationML format. Finally, due to some limitations observed, the design and implementation of a company internal tool is performed. Tests and validation of the tool are performed on a sample production line of the company.

A framework for the environmental risk assessment of offshore carbon storage in CCS systems

Carbon capture and storage (CCS) represents an interesting climate mitigation option, however, as for any other human activity, there is the impelling need to assess and manage the associated risks. This study specifically addresses the marine environmental risk posed by CO2 leakages associated to CCS subsea engineering system, meant as offshore pipelines and injection / plugged and abandoned wells. The aim of this thesis work is to start approaching the development of a complete and standardized practical procedure to perform a quantified environmental risk assessment for CCS, with reference to the specific activities mentioned above. Such an effort would be of extreme relevance not only for companies willing to implement CCS, as a methodological guidance, but also, by uniformizing the ERA procedure, to begin changing people’s perception about CCS, that happens to be often discredited due to the evident lack of comprehensive and systematic methods to assess the impacts on the marine environment. The backbone structure of the framework developed consists on the integration of ERA’s main steps and those belonging to the quantified risk assessment (QRA), in the aim of quantitatively characterizing risk and describing it as a combination of magnitude of the consequences and their frequency. The framework developed by this work is, however, at a high level, as not every single aspect has been dealt with in the required detail. Thus, several alternative options are presented to be considered for use depending on the situation. Further specific studies should address their accuracy and efficiency and solve the knowledge gaps emerged, in order to establish and validate a final and complete procedure. Regardless of the knowledge gaps and uncertainties, that surely need to be addressed, this preliminary framework already finds some relevance in on field applications, as a non-stringent guidance to perform CCS ERA, and it constitutes the foundation of the final framework.

One-loop quantum gravity in arbitrary dimensions

In the context of perturbative quantum gravity, the first three Seeley-DeWitt coefficients represent the counterterms needed to renormalize the graviton one-loop effective action in $D=4$ dimensions. A standard procedure to compute them is by means of the traditional heat kernel method. However, these coefficients can be studied also from a first quantization perspective through the so-called $\mathcal{N} = 4$ spinning particle model. It relies on four supersymmetries on the worldline and a set of worldline gauge invariances. In the present work, a different worldline model, able to reproduce correctly the Seeley-DeWitt coefficients in arbitrary dimensions, is developed. After a covariant gauge-fixing procedure of the Einstein-Hilbert action with cosmological constant, a worldline representation of the kinetic operators identified by its quadratic approximation is found. This quantum mechanical representation can be presented in different but equivalent forms. Some of these different forms are discussed and their equivalence is verified by deriving the gauge invariant counterterms needed to renormalize quantum gravity with cosmological constant at one-loop.

Keyword-based multimedia data lookup in decentralized systems

I sistemi decentralizzati hanno permesso agli utenti di condividere informazioni senza la presenza di un intermediario centralizzato che possiede la sovranità sui dati scambiati, rischi di sicurezza e la possibilità di colli di bottiglia. Tuttavia, sono rari i sistemi pratici per il recupero delle informazioni salvate su di essi che non includano una componente centralizzata. In questo lavoro di tesi viene presentato lo sviluppo di un'applicazione il cui scopo è quello di consentire agli utenti di caricare immagini in un'architettura totalmente decentralizzata, grazie ai Decentralized File Storage e alla successiva ricerca e recupero di tali oggetti attraverso una Distributed Hash Table (DHT) in cui sono memorizzati i necessari Content IDentifiers (CID).\\ L'obiettivo principale è stato quello di trovare una migliore allocazione delle immagini all'interno del DHT attraverso l'uso dell'International Standard Content Code (ISCC), ovvero uno standard ISO che, attraverso funzioni hash content-driven, locality-sensitive e similarity-preserving, assegna i CID IPFS delle immagini ai nodi del DHT in modo efficiente, per ridurre il più possibile i salti tra i nodi e recuperare immagini coerenti con la query eseguita. Verranno, poi, analizzati i risultati ottenuti dall'allocazione dei CID delle immagini nei nodi mettendo a confronto ISCC e hash crittografico SHA-256, per verificare se ISCC rappresenti meglio la somiglianza tra le immagini allocando le immagini simili in nodi vicini tra loro.

Dinàmica de sistemes mesoscòpics amb correlacions quàntiques mitjançant la formulació de de Broglie-Bohm

Per a determinar la dinàmica espai-temporal completa d’un sistema quàntic tridimensional de N partícules cal integrar l’equació d’Schrödinger en 3N dimensions. La capacitat dels ordinadors actuals permet fer-ho com a molt en 3 dimensions. Amb l’objectiu de disminuir el temps de càlcul necessari per a integrar l’equació d’Schrödinger multidimensional, es realitzen usualment una sèrie d’aproximacions, com l’aproximació de Born–Oppenheimer o la de camp mig. En general, el preu que es paga en realitzar aquestes aproximacions és la pèrdua de les correlacions quàntiques (o entrellaçament). Per tant, és necessari desenvolupar mètodes numèrics que permetin integrar i estudiar la dinàmica de sistemes mesoscòpics (sistemes d’entre tres i unes deu partícules) i en els que es tinguin en compte, encara que sigui de forma aproximada, les correlacions quàntiques entre partícules. Recentment, en el context de la propagació d’electrons per efecte túnel en materials semiconductors, X. Oriols ha desenvolupat un nou mètode [Phys. Rev. Lett. 98, 066803 (2007)] per al tractament de les correlacions quàntiques en sistemes mesoscòpics. Aquesta nova proposta es fonamenta en la formulació de la mecànica quàntica de de Broglie– Bohm. Així, volem fer notar que l’enfoc del problema que realitza X. Oriols i que pretenem aquí seguir no es realitza a fi de comptar amb una eina interpretativa, sinó per a obtenir una eina de càlcul numèric amb la que integrar de manera més eficient l’equació d’Schrödinger corresponent a sistemes quàntics de poques partícules. En el marc del present projecte de tesi doctoral es pretén estendre els algorismes desenvolupats per X. Oriols a sistemes quàntics constituïts tant per fermions com per bosons, i aplicar aquests algorismes a diferents sistemes quàntics mesoscòpics on les correlacions quàntiques juguen un paper important. De forma específica, els problemes a estudiar són els següents: (i) Fotoionització de l’àtom d’heli i de l’àtom de liti mitjançant un làser intens. (ii) Estudi de la relació entre la formulació de X. Oriols amb la aproximació de Born–Oppenheimer. (iii) Estudi de les correlacions quàntiques en sistemes bi- i tripartits en l’espai de configuració de les partícules mitjançant la formulació de de Broglie–Bohm.