Dissertations / Theses on the topic 'Efficient use of resources'

This work proposes a vision on the growing scenario of Smart Grids, where a pervasive introduction of distributed generators and innovative power management schemes forces a deep review of the power distribution network establishment. Despite a potentially general value of the proposed approach, the analysis is focused on low voltage microgrids as the most flexible and open architectures to demonstrate the feasibility of the network renewal. In recent years, distribution network has experienced a massive introduction of Distributed Generators (DGs). So far, this has been done based on a hierarchical government of the network, where utilities set regulations and keep control of the connections from the top of the structure. The final user has a passive role in the management, even participating to generation, owning a DG unit. This is basically due to historical reasons: the distribution architecture has been built starting from a centralized controller driven paradigm, and all the updates have been done in the same direction. This approach has been valid until the electrical generation was supplied by a limited number of large plants: huge amounts of power with all the related control challenges, but static generation infrastructure. The upcoming scenario is instead a generation that is strongly decentralized toward distributed energy resources. At the same time, development of Information and Communication Technologies (ICT) is constantly rising. The combination of these two phenomena has the potential to change completely the power distribution system, both in the architecture and in the roles of players in the energy market. From an architectural point of view, distributed generation units could become a combination of renewable sources such as solar, wind, small hydro turbines, fuel cells etc. and traditional sources like gas or diesel generators required for supply continuity of sensible loads. Coupled to the primary energy sources, Energy Storage (ES) can be used to introduce a degree of freedom in energy management: large storage units like batteries or flywheels can absorb the excess of generation, to provide energy during peak demand times, or perform more complex optimizations. Small energy sources, like super capacitors, can be used to improve power quality during transients such as voltage sags or frequency variation transients. These generation and storage units shall be equipped 6 6 with an intelligent digital controller able to measure all the required local variables and perform local control of power converters and also capable to communicate in a bidirectional way, for example via Power Line Communication, with other generators. The power topology of these conversion units can be generally represented as a first conversion stage, dependent on the kind of energy source, and a second stage that is a current controlled inverter. Such devices are named “Energy Gateways” (EG) and represent the basic elements of future Smart Grids in the vision presented in this work. To limit the system complexity, a microgrid is considered: the microgrid is connected to the main low voltage distribution network and presents a number of distributed generators, all equipped with EG. In the proposed approach control of the micro grid is distributed, without centralized controllers: the microgrid internal behaviour can be optimized, as well as the microgrid behaviour seen by the main grid, based on EG to EG communication and control architecture. Considered the degrees of freedom of the resulting system, different optimizations could be performed. In more details, the optimization considered in this work is the distribution loss minimization and it is obtained by properly controlling converters active and reactive power references in a distributed way. In particular, the normal overrating of power converters opens the possibility of injecting distributed reactive power, that can be locally delivered to the loads, reducing the absorption from the main grid and the consequent losses and voltage drops. Also the active power can be partially controlled, depending on the availability of energy storage or controllable generation units. Different techniques have been proposed: stand-alone Energy Gateways with power references control based on local measurement only, without need for communication, or distributed solution where each EG communicates with the surrounding EGs, computes its optimum local power reference and leaves the control to another EG with a Token Ring logic: iterating the local optimization, the system converges to a global optimum of the loss. The optimization is a constrained optimization, depending on power availability, limited by converters power ratings and by distributed generators and storages, and the effects of these constraints are taken into account in the distributed optimization analysis. The analysis have been performed first analytically and then by simulation, developing a specific set of Matlab scripts that gives a flexible tool to define and test every microgrid and its generators and loads, over which the distributed control algorithms have been developed. Some of the major limits of these techniques have been addressed, among them the need for transmission of synchrophasor with tight real-time requirements. At the end, a sub-optimum controller is proposed, expecting to overcome the over mentioned limits that will be developed in the continuation of this research activity. Abstract 7 7 In parallel to this first topic, a second more specific problem has been investigated, representing another aspect of the Smart Grid paradigm. As part of a visiting period with the PEMC (Power Electronics Machines and Control) group at the University of Nottingham, the combination of a STATCOM with energy storage and an engine powered synchronous generator has been studied to smooth the frequency variations during sudden load changes. This represents one of the applications of limited energy storage with high dynamic capabilities, like supercapacitors and is of interest both as retrofit of existing synchronous generators, that could experience disconnection problems in a more dynamic environment represented by the Smart Grid, and as a way of ensuring power quality in a microgrid fed by a backup generator. The first application requires a radical increase in the power size of the system, while the second one is more centred on Smart microgrids: independently on the control approach, a microgrid has to be designed to support islanded operation, i.e. to be able to feed loads even when disconnected from the main power network, and one of the options for this backup supply of the microgrid is the use of synchronous generators as emergency voltage sources, typically with diesel engines as prime movers. This second scenario has been considered and studied and an innovative control technique has been proposed able to ride through step changes in the load demand without changes in the prime mover speed and therefore without large changes in the voltage frequency. This has been achieved through fast active power injection from the energy storage as soon as the load transient is detected. From a qualitative point of view, the new load power demand is supported by the storage until the synchronous generator prime mover overcomes the related transient. This technique has been investigated in simulation and validated in a 10kVA experimental setup, representing a simple isolated microgrid with a single generator and resistive loads, confirming the effectiveness of the proposal.<br>Questo lavoro ha l’obiettivo di analizzare alcuni aspetti del nuovo scenario delle Smart Grid, dove la vasta introduzione di generazione distribuita e di tecniche innovative di gestione dell’energia sta forzando una profonda revisione dell’attuale rete di distribuzione. Nonostante i temi affrontati abbiano validità generale, l’analisi presentata si concentra sulle microreti in bassa tensione. Questo perché la bassa tensione, a maggior ragione se limitata a una specifica area identificata da una microrete, è l’architettura più flessibile ed aperta all’introduzione di soluzioni innovative. Recentemente, la rete di distribuzione ha visto l’introduzione di un gran numero di generatori distribuiti, introduzione finora basata su una rigida struttura gerarchica all’interno della rete, dove i gestori mantengono il completo controllo sull’installazione e sulla gestione degli impianti. Questo è legato soprattutto a ragioni storiche: la rete di distribuzione si basa su un paradigma di controllo centralizzato, dove i flussi di potenza sono unidirezionali. La generazione avviene in un numero limitato di centrali e la potenza viene distribuita ai carichi, in un’architettura rigida e totalmente controllata. Lo scenario emergente delle Smart Grid propone invece una generazione fortemente decentralizzata, basata su un gran numero di sorgenti di energia distribuite, anche di potenza medio bassa. Allo stesso tempo, il settore dell’ICT (Information and Communication Technology) è in continua crescita. La combinazione di generazione distribuita e ICT ha la potenzialità di cambiare completamente il sistema di distribuzione dell’energia, sia da un punto di vista architetturale che del ruolo delle parti nel mercato dell’energia. Da una prospettiva architetturale, la generazione distribuita potrebbe evolvere verso una soluzione ibrida tra sorgenti rinnovabili quali fotovoltaico, eolico, celle a combustibile ed idroelettrico e fonti tradizionali a combustione, quali turbine a gas e generatori diesel, queste ultime in grado di garantire continuità di alimentazione ai carichi più sensibili in qualsiasi condizione. Inoltre, un accumulo energetico (Energy Storage, ES) può essere usato per introdurre un grado di libertà aggiuntivo nella gestione dell’energia: batterie o flywheels possono assorbire la generazione in eccesso, per fornire energia durante i picchi di carico. Accumuli energetici di ridotta capacità, 10 10 quali i supercondensatori, possono invece aumentare la qualità della potenza fornita ai carichi, essendo in grado di rispondere velocemente a transitori della microrete, quali variazioni di frequenza e buchi di tensione. Queste unità di generazione ed accumulo devono essere interfacciate alla rete attraverso un convertitore di potenza, equipaggiato con un controllore digitale in grado di misurare e controllare variabili locali per il corretto funzionamento del convertitore stesso, ma anche in grado di comunicare in modo bidirezionale con altri controllori, ad esempio attraverso PLC (Power Line Communication). La struttura di conversione risultante è stata definita in questo lavoro “Energy Gateway”, (EG), e rappresenta l’elemento portante delle future Smart microgrids nella visione proposta da questo lavoro. Per limitare la complessità del sistema, l’analisi proposta è focalizzata sulle microreti: una microrete è connessa alla rete di distribuzione tradizionale a bassa tensione, e presenta al suo interno un certo numero di generatori distribuiti, tutti equipaggiati con EG. Nell’approccio proposto, il controllo della microrete è distribuito, senza la presenza di un controllore centrale che gestisce tutte le sorgenti di energia. Il comportamento interno della microrete può così essere gestito da interazioni tra le diverse sorgenti, allo scopo di mostrare al punto di connessione con la rete tradizionale un certo comportamento equivalente desiderato, oppure per ottimizzare il funzionamento della microrete secondo parametri prestabiliti. Entrando nel dettaglio, l’ottimizzazione considerata in questo lavoro è la minimizzazione delle perdite di distribuzione all’interno della microrete, ed è ottenuta controllando opportunamente i riferimenti di potenza attiva e reattiva dei convertitori con un approccio distribuito. In particolare, il normale sovradimensionamento dei convertitori permette di iniettare nella microrete potenza reattiva distribuita, che viene fornita ai carichi localmente. In questo modo si riduce l’assorbimento dalla rete di distribuzione principale, così riducendo perdite e cadute di tensione. Anche l’iniezione di potenza attiva può essere parzialmente controllata, a seconda della disponibilità di energia accumulata negli EG o di sorgenti di energia totalmente controllabili (i.e. gas turbines, diesel generators, fuel cells). Questo lavoro propone diverse soluzioni per minimizzare le perdite di distribuzione di una microrete: Energy Gateways con riferimenti di potenza controllati usando come informazioni solo variabili misurate localmente, senza nessuna comunicazione, oppure soluzioni distribuite dove gli Energy Gateways comunicano e ognuno di essi esegue una minimizzazione locale delle perdite, basandosi solo su informazioni ricevute dai generatori vicini. Iterando l’ottimizzazione locale, la microrete converge al minimo globale delle perdite di distribuzione. L’ottimizzazione è analizzata considerando i vincoli imposti dai limiti di dimensionamento dei convertitori degli Energy Gateways. L’analisi è stata sviluppata prima analiticamente e successivamente in simulazione, sviluppando un codice Matlab per definire la microrete e testare le diverse soluzioni di ottimizzazione distribuita. Abstract 11 11 In parallelo alla minimizzazione delle perdite è stato sviluppato anche un secondo argomento, che rappresenta un altro aspetto del paradigma delle Smart Grid. Durante il periodo all’estero speso presso il PEMC (Power Electronics Machines and Control) group all’università di Nottingham, è stata studiata la combinazione tra uno STATCOM con accumulo energetico e un generatore sincrono mosso da un motore diesel, allo scopo di minimizzare la variazione di frequenza del generatore, che si verifica durante variazioni a gradino del carico. L’applicazione è importante sia come adattamento di impianti di generazione esistenti, che potrebbero trovarsi in situazioni di criticità in una rete in cui si verificano frequenti variazioni di carico, e sia come tecnica con cui garantire stabilità in frequenza in una microrete alimentata da un singolo generatore diesel di backup in mancanza della rete principale. Questo secondo caso è stato investigato nel dettaglio, in quanto più orientato alle microreti: ogni microrete deve prevedere un backup energetico per garantire il funzionamento in isola, e il generatore diesel è una delle possibili soluzioni. In questo lavoro è stata proposta una tecnica di controllo innovativa, capace di superare transitori di carico con variazione trascurabile della frequenza generata. L’obiettivo è stato raggiunto grazie ad un’iniezione di potenza attiva attraverso lo STATCOM durante il transitorio di carico. Da un punto di vista qualitativo, lo STATCOM e il suo accumulo energetico sopperiscono al maggior o minor carico nell’intervallo di tempo necessario al motore diesel per aggiornare la sua potenza di uscita. La tecnica è stata prima testata in simulazione e successivamente validata su un prototipo sperimentale che ha ricreato una microrete elementare con generatore sincrono e STATCOM da 10kVA e carichi resistivi, confermando l’efficacia della soluzione proposta.

Rice, as a major staple crop, is one of the most important targets for plant breeders in an attempt to secure enough food for a growing world population. Producing nutrient efficient crops has become essential not only to attempt securing enough food for the growing population, but also to eliminate environmental consequences of using fertilizers. Nitrogen (N), phosphorus (P) and potassium (K) are major macronutrients that are rate limiting for plant growth and crop productivity. The aims of this project were to explore the genetic diversity of rice to identify genotypes with high efficiency under N, P and K deficient conditions, to identify chromosomal loci linked to NPK use efficiency using Genome Wide Association Studies (GWAS), and to manipulate a proton pump using CRISPR/Cas9 system with the aim of improving mycorrhiza-dependent nutrient uptake. Biomass and elemental analyses revealed considerable variations among 294 rice genotypes, and a subset of genotypes was identified that were relatively tolerant to NPK nutrient limitation. GWAS study revealed novel and previously known QTLs and genes with potential importance to the use efficiency of N, P and K. Alongside with N and K transporters and regulatory proteins, unexpectedly several genes involved in Na transport were identified as candidates. The CRISPR/Cas9 system was successfully applied to manipulate several candidate genes identified from GWAS, in addition to the rice H+-ATPase (OsHA1). Overall, the findings from this study can be used as a basis to conduct similar studies in other crops, which can all contribute to improve crop production, sustainable agriculture and food security.

In the conditions of scientific and technical progress, the growth of capital productivity of fixed assets, which in modern conditions is complicated by rapid change of equipment, and also by an increase in capital investments directed at improving working conditions, is of great importance for the effective use of the resource potential of the enterprise.

Abstract Volatile Organic Compounds (VOCs) in wastewaters from the chemical industry are of major concern because of their environmental and health impacts. The reclamation of VOCs from wastewaters would not only reduce the hazard to the environment but also contribute to an efficient use of resources. The thesis explores the reclamation of n-butanol and dichloromethane from sodium chloride containing mixtures by pervaporation. Another aim was to gain understanding of mass transport phenomena during the pervaporation of multicomponent systems, and the effect of sodium chloride on the pervaporation performance. In this work, the reclamation of n-butanol and dichloromethane was conducted as a sequence of pervaporation stages which utilised first hydrophobic and then hydrophilic membranes. The objective was to segregate the mixture of n-butanol/dichloromethane/sodium chloride/water into three different streams: a re-use quality concentrate of VOCs, brine, and discharge quality purified water. The effect of the experimental variables, VOCs feed concentration, feed temperature and sodium chloride content on the performance of the pervaporation stages was studied. A statistical design, response surface methodology, was used to further resource efficiency. The results indicate the potential of pervaporation for the reclamation of n-butanol and dichloromethane from aqueous mixtures. A single step of pervaporation of n-butanol/dichloromethane/sodium chloride/water systems using the CMX-GF-010-D (Celfa) and PERTHESE® 500-1 (P 500-1) membranes does not sufficiently concentrate the VOCs for direct re-use. It is also demonstrated that the electrolyte does not permeate through the membranes and does not affect their separation effectiveness significantly. The pervaporation of the water/dichloromethane/n-butanol system using the hydrophilic poly(vinyl alcohol)-titanium dioxide/polyacrylonitrile/polyphenylene sulfide (PVA-TiO2/PAN/PPS) membrane is effective for dewatering purposes. The membrane shows impermeable features towards dichloromethane in the studied conditions. The analysis of the mass transport phenomena demonstrates that, under the experimental conditions studied, the resistance towards the mass transport of the compounds through the membrane is mainly exhibited by the membrane itself. This study also shows the advantage of analysing the effect of temperature on membrane permeation by the permeation activation energy instead of by the apparent activation energy.

1. Ovsyuk, NV (2014). Staff motivation: essence and modern problems. Business inform, (2). 2. Cherep AV Methodical approaches to assessing the effectiveness of the use of labor potential of enterprises. URL: http://www.agro-svit.info/pdf/15_2012/12.pdf.<br>The essence of the category "staff" is considered. The approaches and methods of estimating the efficiency of the use of labor resources at the enterprise are revealed, the factors influencing them are investigated.<br>Розглянуто сутність категорії «персонал». Розкриті підходи та методи оцінки ефективності використання трудових ресурсів на підприємстві, досліджені фактори, що впливають на них.

The building industry accounts for around one third of the total energy use and GHG emissions in Sweden. Despite the implementation of energy efficiency measures focusing on new buildings, embodied impacts from material extraction, manufacturing, construction and maintenance have grown in significant proportions. While cities like Stockholm are currently experiencing a strong demographic growth and a high pressure on the supply of new spaces and facilities for new residents, national environmental goals aim to reduce energy use and GHG emissions in the coming decades. For instance, the new Climate Act in Sweden expects the country to become carbon neutral by 2045 and the European Commission urges the decarbonisation of national building stocks by 2050. The dual pressure of growth and environmental targets urges the exploration of alternatives for the supply and use of space. In fact, some sources indicate that many spaces remain unused during several hours a day/week and estimations show that most of the buildings that will be in use in 2050 have already been built today. This study explores the potential for a resource-efficient use of space in the existing building stock in Stockholm, leading to a positive impact on the reduction of energy consumption and GHG emissions. The inquiry is conducted with a mixed methods approach in three sequential steps: the identification of relevant stakeholders, instruments and initiatives; the analysis of use of space in a sample of commercial spaces at the street level; and the formulation of strategies allowing an increase in their temporal and spatial capacity. The study suggests that one way to optimise the use of space in existing buildings is to create new property rights. Specifically, it illustrates how merging commercial spaces on the street level through the constitution of 3D properties can increase the capacity to accommodate activities in space and time. Together with digitalisation and the development of new services based on sharing solutions, this opens up new possibilities for decreasing new construction and to absorb new demands for heated floor area.

<p>To address increasing irrigation water demand consecutive to the increasing population pressure in terms of food demand, there is an imperative of developing relevant mechanisms to regulate irrigation water consumption patterns. A radical shift from uncontrolled flooding irrigation as currently practiced by farmers in Mugerero paddy farming zone towards efficient allocation and use of water resources is important to save water that could be allocated to other water users.</p><p>This paper surveys current and past views on the way irrigation water is allocated in the irrigation scheme of Mugerero and how farmers are using water for paddy production purpose. The existing irrigation water practices as well as paddy productivity are assessed and the results are expected to be useful for water policy professionals, while addressing the growing water demand. According to the respondents, the causes of low paddy yields are the increasing and uncontrolled extension of paddy farming, non adapted irrigation infrastructure and water pricing systems as well as lack of updated knowledge and technologies on irrigation. These issues faced by the paddy farmers have led to pronounced economic, social and environmental consequences which are manifested in conflicts over irrigation water use, increasing soil salinity and pollution, destruction of infrastructure and above all, low irrigation paddy yields.The identification of the core problem in the irrigation system might be important for water managers as it would provide a starting point to establish comprehensive baseline towards efficient irrigation water allocation and use. This would improve paddy productivity within the formal as well as the growing informal paddy farming referred to “hors- perimeter” in the low land of Imbo region.</p>

Dans ce travail, nous nous intéressons à la modélisation des ressources Cloud, indépendamment des couches existantes, afin d’apporter un cadre (framework) de représentation unique et ouvert à l'arrivée anticipée du XaaS (Anything as a Service). Nous fournissons, à l'aide de ce framework, un outil de placement des ressources pour une plate-forme donnée. Les travaux de thèse se portent aussi sur la prise en compte des intérêts des utilisateurs ou consommateurs et des fournisseurs. Les solutions existantes ne se focalisent que sur l’intérêt des fournisseurs et ce au détriment des consommateurs contraints par le modèle d’affaire des fournisseurs. La thèse propose des algorithmes évolutionnaires en mesure de répondre à cet objectif<br>This thesis focuses on optimal and suboptimal allocation of cloud resources from infrastructure providers taking into account both the users or consumers and the providers interests in the mathematical modeling of this joint optimization problem. Compared to the state of the art that has so far remained provider centric, our algorithms optimize the dynamic allocation of cloud resources while taking into account the users and the providers objectives and requirements and consequently frees the users (or consumers) from provider lock in (providers’ business interests). Evolutionary algorithms are proposed to address this challenge and compared to the state of the art

Dans ce travail, nous nous intéressons à la modélisation des ressources Cloud, indépendamment des couches existantes, afin d’apporter un cadre (framework) de représentation unique et ouvert à l'arrivée anticipée du XaaS (Anything as a Service). Nous fournissons, à l'aide de ce framework, un outil de placement des ressources pour une plate-forme donnée. Les travaux de thèse se portent aussi sur la prise en compte des intérêts des utilisateurs ou consommateurs et des fournisseurs. Les solutions existantes ne se focalisent que sur l’intérêt des fournisseurs et ce au détriment des consommateurs contraints par le modèle d’affaire des fournisseurs. La thèse propose des algorithmes évolutionnaires en mesure de répondre à cet objectif<br>This thesis focuses on optimal and suboptimal allocation of cloud resources from infrastructure providers taking into account both the users or consumers and the providers interests in the mathematical modeling of this joint optimization problem. Compared to the state of the art that has so far remained provider centric, our algorithms optimize the dynamic allocation of cloud resources while taking into account the users and the providers objectives and requirements and consequently frees the users (or consumers) from provider lock in (providers’ business interests). Evolutionary algorithms are proposed to address this challenge and compared to the state of the art

The Swedish electricity system is transitioning due to the establishment of climate policy goals and trends related to technology and demographics. The transition has resulted in an increased demand for electricity. The increased demand for electricity in combination with lack of forecasts, planning and coordination between actors in the electricity sector has led to the occurrence of grid congestion. Extending the network is time-consuming and requires substantial investments. Instead, an alternative is to utilise the available grid capacity more efficiently by implementing flexibility solutions. Flexibility can be achieved by implementing incentives such as grid tariffs. This solution has recently gained much attention in Sweden, but it is not apparent how grid tariffs should be designed. The purpose of this thesis is to investigate how distribution grid tariffs could be designed to incentivise different actors to contribute to flexibility in a way that results in an efficient use of the electrical grid. A qualitative study was performed, collecting empirical data through semistructured interviews with actors in the Swedish electricity market. The aim is that the results from this thesis will act as a basis for DSOs planning to design grid tariffs with the purpose to utilise the grid more efficiently. The findings present a ToU capacity charge with off-peak periods that are free of charge as the preferable main price signal in the tariff to achieve efficient utilisation of the grid. It is further argued that other structural elements can complement the ToU capacity charge. A small fixed charge could be added in order to contribute to the cost reflectiveness of the grid tariff. A small energy charge could be incorporated in order to provide consumer with incentives to be flexible below the current metered maximum power and strengthen the signal from the ToU capacity charge. A small energy charge can avert difficulties related to providing incentives below the current metered maximum, as it still can provide some incentives to be flexible, or strengthen the signal from the ToU capacity charge. Further, the energy charge can ensure sustainability if customers respond well to a ToU capacity charge and to compensate solar PV customers. Furthermore, recommendations to further enable the grid tariffs potential to provide price signals include shifting the focus of the revenue cap from CapEx to OpEx and exploring the hampering signals of the energy tax as well as contradicting price signals from the wholesale electricity price.<br>Det svenska elsystemet genomgår en förändring till följd av införandet av klimatmål och trender relaterade till teknik och demografi. Denna förändring har resulterat i ett ökat effektbehov. Ett ökat effektbehov i kombination med bristande prognostisering, planering och samordning mellan aktörer inom elsektorn har lett till uppkomsten av kapacitetsbrist. Att bygga ut elnätet är tar tid och kräver större investeringar. Ett alternativ är att istället utnyttja det befintliga elnätet mer effektivt genom att implementera flexibilitetslösningar. Flexibilitet kan uppnås genom att införa incitament i form av elnätstariffer. Denna lösning har nyligen fått mycket uppmärksamhet i Sverige, men det är inte klart inte hur dessa elnätstariffer ska utformas. Syftet med detta arbete är att undersöka hur distributionsnätets tariffer kan utformas för att stimulera olika aktörer att bidra med flexibilitet på ett sätt som resulterar i en effektiv användning av det befintliga elnätet. En kvalitativ studie genomfördes där empiriska data samlades in genom semistrukturerade intervjuer med aktörer på den svenska elmarknaden. Syftet är att resultaten från detta arbete ska fungera som ett underlag för nätägare som planerar att utforma elnätstariffer med syftet att utnyttja nätet mer effektivt. Resultaten visar att en ToU-effektavgift med gratis off-peak perioder bör vara den huvudsakliga prissignalen i en elnätstariff som ämnar att utnyttja det befintliga nätet mer effektivt. Det visar även att andra strukturella element kan komplettera ToU-effektavgiften. En mindre fast avgift kan adderas i syfte att göra elnätstariffen mer kostnadsriktig. En mindre energiavgift kan införas för att ge kunder incitament att vara flexibla även under den nuvarande uppmätta maximala effekten och stärka signalen från ToU-effektavgiften. Vidare kan energiavgiften säkerställa tillräckliga intäkter för nätägaren om kunderna svarar bra på en ToU-effektavgift och för att kompensera kunder med solceller. Ytterligare rekommendationer för att möjliggöra prissignaler genom elnätstariffer inkluderar att skifta fokus på intäktsramen från CapEx till OpEx och utforska de hämmande prissignalerna från energiskatten och de motstridiga prissignalerna från elhandelspriset.

The study was based on six villages along two sample transects, i.e. the Karakoram Highway (KKH) transect (good road and market infrastructure) and the Gilgit Ghizar Region (GGR) transect (poor road and market infrastructure).  The primary objective was to examine if there were differences in pasture use due to infrastructure development.  In each village, pastures were categorised into three broad vegetation types on the basis of altitude, i.e. foothill (<1500m), dry temperate (1500-3000m) and alpine (>3000m).  Within each vegetation type pastures were selected for measuring vegetation by quadrats of varying sizes.  Vegetation changed from very sparse shrubs in foothill to less sparse shrubs in dry temperature to grass/forbs in alpine pastures.  One foothill, three dry temperate and four alpine communities were identified.  Availability of water was the main factor that affected the structure and composition of vegetation in the area.  Biomass and production was high in the alpine as compared to foothill and dry temperature pastures during different seasons.  Production was high during spring in the dry temperature pastures.  Altitude change did affect biomass, however production was less affected.  Both biomass and production were better on the moderate as compared to gentle slopes.  The nutritive value of herbage was highest during spring season overall.  Alpine pastures had higher use than dry temperate and foothill pastures in all seasons.  Production was higher than use in the dry temperate pastures during spring season.  The livestock density did not differ between the KKH and GGR transects.  The alpine pastures had higher livestock density.  There was no significant difference in pasture use by livestock between the KKH and GGR transects.  The main difference was in the use between different villages, particularly during spring season.  There was higher use of the alpine pastures of different villages on both the transects (concordant with livestock densities).

Depuis le milieu des années 1990, l’utilisation de Dispositifs de Concentration de Poissons (DCP), des objets artificiels spécifiquement mis à l’eau pour agréger des bancs de poissons, est devenue de plus en plus importante pour la pêche au thon tropical à la senne. Cette utilisation massive des DCP, qui s’accompagne d’une utilisation massive de dispositifs de suivi comme les balises GPS et les balises échosondeurs, est aujourd’hui source d’inquiétude pour les stocks de thons, les prises accessoires mais aussi pour le fonctionnement des écosystèmes pélagiques. Cependant, les modalités d’utilisation des DCP et des balises GPS qui servent à les suivre restent mal connues, ce qui complique considérablement l’évaluation et la gestion des impacts de ces pratiques de pêche. Afin d’améliorer les connaissances actuelles de la pêcherie, les positions des balises GPS utilisées par les 3 armements français dans les océans Atlantique et Indien, constituant une part significative des DCP utilisés dans ces deux océans, ont été analysées. Ces données ont été combinées avec des multiples sources d’information : les livres de bord, les trajectoires VMS des senneurs français ainsi que des entretiens avec les patrons français. Elles nous permettent de mieux comprendre les stratégies de mise à l’eau des DCP et des balises, d’estimer le nombre d’objets flottants utilisés par les flottes de senneurs dans les océans Atlantique et Indien, de mesurer la contribution des DCP et des navires auxiliaires à l’efficacité de pêche des senneurs, d’identifier des destructions potentielles d’habitats par les DCP échoués and pour finir de proposer des solutions de gestion pour la pêcherie. Les résultats montrent une grande saisonnalité dans les mises à l’eau des deux océans, une croissance rapide du nombre de balises GPS au cours des 7 dernières années puisqu’elle est multipliée par 4.2 dans l’Océan Indien et 7 dans l’Océan Atlantique, des dommages possibles causés à des écosystèmes côtiers fragiles avec une probabilité d’échouage de l’ordre de 10% et finalement une augmentation de l’efficacité de pêche entre 2003 et 2014 de l’ordre de 3.8-18.8% dans l’Océan Atlantique et 10.7%-26.3% dans l’Océan Indien. Les entretiens avec les capitaines des senneurs soulignent la nécessité d’une gestion plus efficace de la pêcherie, avec entre autres l’instauration de quotas, une régulation de la capacité de la flotte de senneurs et un meilleur suivi des navires auxiliaires. Les résultats obtenus constituent les premières étapes nécessaires à une meilleure gestion de la pêche sous objet flottant<br>Since the mid 1990s, the use of drifting Fish Aggregating Devices (dFADs) by purse seiners, artificial objects specifically designed to aggregate fish, has become an important mean of catching tropical tunas. In recent years, the massive deployments of dFADs, as well as the massive use of tracking devices on dFADs and natural floating objects, such as GPS buoys, have raised serious concerns for tropical tuna stocks, bycatch species and pelagic ecosystem functioning. Despite these concerns, relatively little is known about the modalities of GPS buoy tracked objects use, making it difficult to assess and manage of the impacts of this fishing practice. To fill these knowledge gaps, we have analyzed GPS buoy tracks provided by the three French fishing companies operating in the Atlantic and the Indian Oceans, representing a large proportion of the floating objects monitored by the French fleet. These data were combined with multiple sources of information: logbook data, Vessel Monitoring System (VMS) tracks of French purse seiners, information on support vessels and Local Ecological Knowledge (LEK) of purse seine skippers to describe GPS buoy deployment strategies, estimate the total number of GPS buoy equipped dFADs used in the Atlantic and Indian Oceans, measure the contribution of strategies with FOBs and support vessels to the fishing efficiency of tropical tuna purse seiners, identify potential damages caused by lost dFADs and finally to propose management options for tropical tuna purse seine FOB fisheries. Results indicate clear seasonal patterns of GPS buoy deployment in the two oceans, a rapid expansion in the use of dFADs over the last 7 years with an increase of 4.2 times in the Indian Ocean and 7.0 times in the Atlantic Ocean, possible damages to fragile coastal ecosystems with 10% of GPS buoy tracks ending with a beaching event and an increased efficiency of tropical tuna purse seine fleets from 3.9% to 18.8% in the Atlantic Ocean over 2003-2014 and from 10.7% to 26.3% in the Indian Ocean. Interviews with purse seine skippers underlined the need for a more efficient management of the fishery, including the implementation of catch quotas, a limitation of the capacity of purse seine fleets and a regulation of the use of support vessels. These results represent a first step towards better assessment and management of purse seine FOB fisheries

Resource efficiency (RE) is a characteristics of the way resources such as energy and materials are used within everyday activities and it is a critical concern for those working in the fields of climate change mitigation and environmental protection. Resource efficiency affects the rates at which resources are extracted from sources and waste streams such as greenhouse gas emissions and material wastes are generated. This thesis presents six studies in which methods from the fields of management, engineering, and systems thinking were used to evaluate and expand upon existing waste prevention and carbon management methods - two of the real-world approaches being used to improve RE. Insights from these studies were combined to examine RE from several theoretical angles - as a problem of socio-technical transition, as a wicked problem, as a problem full of conundrums, as a problem that can be addressed using systems thinking methods, and as a problem for which an underlying vision has not yet been well articulated and accepted. Key contributions to knowledge from the six studies include: Insights from the trial of a holistic carbon management method for buildings that includes consideration of the interactions between end-use technologies, stakeholder groups, organisational structure, and buildings. The application of critical systems heuristics theory to investigate issues related to competing goals within planning for the low-carbon redevelopment of an urban enterprise zone. A waste prevention model for the UK economy, developed using system dynamics, which produced insights into waste prevention pathways and findings about the usefulness to government of the systems methods used. The development of a theory linking social, economic, technological, and infrastructure factors as an proposed explanation of the causes of Jevons' Paradox; a model of road transport carbon emissions as an application of the theory; and the testing of a suite of four types of interventions that could reduce greenhouse gas emissions enough to meet EU goals by 2030. Key contributions to knowledge from a synthesis of the study findings include: Analysis of RE as a wicked problem, through applying the ten characteristics of wickedness, and implications of this wickedness for RE practice. Analysis of RE as a problem of socio-technical transition, through developing a Causal Stratified Sustainability version of the Multi Level Perspective which portrays the relationship between the natural environment, science, and the economy at different stages of maturity. A proposition for a preanalytic vision for the field of RE, with the intended purpose of moving the field of RE away from its mostly pragmatic stance and developing a theoretical grounding from which to improve RE practice in future. A framework of applicability of systems models and methods to RE. Reflections on the use of PS Ms within the field of RE. Personal reflections on the impact of systems methods on my own understanding, and the dualistic role of engineers with regard to RE.

У роботі розглядаються теоретичні аспекти управління оборотними активами на підприємстві шляхом уточнення сутності оборотних активів, їх складу та формування системи управління. Здійснено класифікацію методів управління оборотними активами. Виконано розрахунок ефективної системи показників підприємства. Висвітлено ефективність використання оборотних активів підприємств за допомогою ряду коефіцієнтів. Надано загальну характеристику діяльності компанії ТОВ «Телекарт-Прилад». Проаналізовано фінансовий стан компанії ТОВ «Телекарт-Прилад». Здійснено оцінку управління оборотними активами ТОВ «Телекарт-Прилад». На прикладі обраної компанії виконано аналіз практичної придатності декількох моделей та перевірено їх адекватність. Виявлено, що на ефективне використання оборотних активів впливає безліч факторів, від впливу яких залежить фінансовий стан підприємства. Запропоновані напрямки вдосконалення механізму фінансування та підвищення ефективності використання оборотних активів.<br>The work deals with the theoretical aspects of current assets management in the enterprise by clarifying the essence of current assets, their composition and the formation of the management system. The classification of current assets management methods is carried out. The calculation of the effective system of indicators of the enterprise is executed. The efficiency of the use of current assets of enterprises with the help of a number of coefficients is highlighted. The general characteristic of activity of the Telekart-Prilad LLC company is given. The financial condition of the company LLC "Telecard-Device" is analyzed. The assessment of current assets management of Telekart-Prilad LLC has been carried out. On the example of the selected company the analysis of practical suitability of several models is executed and their adequacy is checked. The scientific work revealed that the effective use of current assets is influenced by many factors, the influence of which depends on the financial condition of the enterprise.The directions of improvement of the mechanism of financing and increase of efficiency of use of current assets are offered.

Modern bread wheat (Triticum aestivum) initially derived from wild progenitors which underwent hybridisation and domestication events. It is hypothesised that modern plant breeding has reduced the genetic variation among modern cultivars (Sparkes, 2010). Ancient wheat species form a conduit between wild ancient wheat and cultivated Triticum species, and may harbour the genetic variation required to supplement the modern bread wheat gene pool. The current work investigated a range of morphological and physiological aspects of several ancient species including several representatives of spelt, emmer and einkorn. These were compared to modern bread wheat in two field and three glasshouse experiments with the aim to investigate their resource use efficiency, where radiation use and water use formed the crux. The main components of the current work relate to 1) canopy interception characteristics 2) leaf photosynthetic capabilities and 3) water use. Spelt genotypes demonstrated increased WUE and green area longevity compared with modern bread wheat. Emmer displayed increased WUE, assessed on three scales using instantaneous transpiration efficiency (ITE), biomass to water uptake ratios, and carbon isotope discrimination (Δ13C). In addition, the mechanisms whereby emmer, einkorn and spelt maintained ITE appeared to differ. Emmer was observed to increase photosynthetic rates, whereas spelt maintained low transpiration as a result of low stomatal conductance. Einkorn however, maintained ITE through an intermediate of both of these mechanisms. This was further supported by species differences for maximum photosynthetic rates (Asat) which, for emmer and einkorn, were comparable with modern bread wheat. Investigation of WUE through Δ13C and biomass production to water uptake ratios ranked species similarly, showing emmer and spelt to have superior WUE during grain filling. Additionally, spelt was observed to produce biomass comparable to modern bread wheat, thought to be due to enhanced RUE (observed in one field trial) or increased green area longevity rather than increased assimilation capability. In field experiments, biomass production and light interception was relatively high for einkorn species, however this was believed to derive from excessive tiller production due to poor emergence. Overall, ancient species did partition a larger proportion of assimilates toward tillers. Modern bread wheat produced fewer tillers, but directed more biomass towards the ear, and therefore had greater harvest indices (HI) compared to all ancient species. Despite this broad analysis, further investigation of the mechanisms responsible for these traits is required. This research therefore indicates that there is sufficient variation for traits, which could be used to improve radiation and water use efficiency, and therefore warrants further exploration. With further investigation, resource capture and utilisation efficiency, and the morphological traits that confer these advantages in these genotypes, genetic markers could be identified with the aim to introduce valuable traits for the production of novel modern bread wheat varieties. The differences observed between these ancient wheat species and modern bread wheat provide an opportunity through which modern wheat gene pools may be improved to stabilise yields, particularly in sub-optimal environmental conditions, thus increasing biomass production per unit resource, thereby enhancing the productivity and the efficiency of crop systems.

У роботі розглянуто теоретичні засади інвестування, сутність, зміст та форми банківських інвестицій та інституційні основи інвестиційно-банківської діяльності, її складу та формування системи управління. Здійснено класифікацію методів управління інвестиційним портфелем банку. Охарактеризовано сучасний стан та особливості розвитку українських банків і на цій основі визначено шляхи формування інвестиційної банківської діяльності з обґрунтуванням місця і ролі комерційних банків; Надано загальну характеристику діяльності банку АТ КБ «Приватбанк». Проаналізовано фінансовий стан банку АТ КБ «Приватбанк». Здійснено оцінку управління інвестиційним портфелем банку АТ КБ «Приватбанк». Надано модель оптимізації кредитного портфеля за умов ризику щодо платоспроможності позичальників. Виявлено, що на ефективне інвестування капіталу банку впливає безліч факторів, від впливу яких залежить фінансовий стан банку. Запропоновані напрямки вдосконалення ризик менеджменту та підвищення ефективності інвестування.<br>The work considers the theoretical principles of investment, the essence, content and forms of banking investments and the institutional foundations of investment banking. It`s composition and the formation of the management system. The classification of bank investment portfolio management methods is carried out. The current state and peculiarities of the development of Ukrainian banks are characterized. On this basis the ways of formation of investment banking activity with the substantiation of the place and role of commercial banks are determined; The general characteristic of activity of bank of JSC CB "Privatbank" is given. The financial condition of the bank JSC CB "Privatbank" is analyzed. The investment portfolio management of the bank JSC CB "Privatbank" was assessed. The model of loan portfolio optimization under conditions of risk in terms of solvency of borrowers is given; It was found that the effective investment of the bank's capital is influenced by many factors, the influence of which determines the financial condition of the bank. The directions of improvement of risk management and increase of efficiency of investment are offered.

In South Africa, precipitation is extremely variable and water is scarce. South Africa is also a country with great welfare needs. Challenging economic development targets and plans therefore need to be implemented successfully within the constraints of limited water supply and unreliable water availability. These economic development plans are underpinned by the development and growth of economic activities such as agriculture, mining, energy production and many types of small, medium and micro enterprises, which are some of the largest water using sectors in the economy. Within these activities, increased competition places pressure on water users to keep supplying their markets with competitively priced goods, while rising costs of new water supplies puts pressure on water users to allocate sufficient water to their production processes. These market forces and the relative scarcity of water as an economic production factor, impact on financial viability and imply that the economic efficiency of water use becomes increasingly important. The National Water Act of 1998 (NWA) is a legislative response to this situation, and promotes a radical shift towards efficiency and equity goals in water allocation. Water users who require water as an input to economic activities are consequently seriously revising their water use patterns in response to one of the major implications of the NWA and its related principal strategy: water demand management. Water demand management strives to adhere to the principles of equity, social justice, economic efficiency and environmental sustainability, which are central to the NWA. This study evaluates the costs and benefits of water use in order to simulate the effects of water demand management activities on a catchment economy. The results of a number of studies were combined to generate an economy-wide model: a Social Accounting Matrix (SAM), for the case study area and to simulate the direct and indirect effects of water demand management on the people, the economy and the natural environment in the area. Water demand management (WDM) is defined as consisting of two phases. In the first phase, goals of full cost recovery, improving water use efficiency and allocating water optimally are targeted. The second phase of WDM arrives when a situation of absolute water scarcity is reached within a catchment. In this phase water demand outweighs water supply and water has to be allocated according to its scarcity value. Water markets play a large role here. The SAM was used to simulate the direct and indirect impacts on the economy and the environment of a number of WDM related scenarios. Water e-allocation decisions and the effects of various WDM policy instruments, such as reduction of water use subsidies and increases in water tariffs were simulated. Unintended consequences of other environmental policies on water use, in this case, carbon tax, were explored. Water scarcity predictions were done, and some of the transaction costs involved in water trading was quantified. The study concludes with a discussion on the indirect effects on the economy, the environment and people of changes affecting the agricultural (including forestry) activities. The direct and indirect impacts of WDM policies on the economy and the environment, and the importance of environmental-economic models in water cost benefit modeling are also discussed. Implications for policy and management are highlighted. This study shows specifically how, through modelling various scenarios, policy decisions aimed at managing specific variables (e.g. water use, carbon emissions) have an economic and environmental impact much wider than the sector in which the policy was targeted for. Each scenario shows how a water transaction, or a change in subsidy in the agricultural (including forestry) sector, could impact on the output of other economic sectors, and therefore the economy as a whole. It is therefore evident that policy decisions, which are implemented at a macro level, and could have a major direct impact on a wider range of economic sectors, should be carefully considered as they could have large, undesirable, unintended consequences.<br>Dissertation (MSc (Agricultural Economics))--University of Pretoria, 2004.<br>Agricultural Economics, Extension and Rural Development<br>MSc (Agric)<br>unrestricted

International Telemetering Conference Proceedings / October 25-28, 1999 / Riviera Hotel and Convention Center, Las Vegas, Nevada<br>In recent years the telemetry community has encountered a growing demand for bandwidth from users and a corresponding loss of spectrum. The Advanced Range Telemetry (ARTM) Program has responded to this situation with an initiative to develop, demonstrate, and improve the management and control of telemetry resources using demand assigned multiple access (DAMA) techniques. This initiative has proceeded along two paths. The first path is in the development of an expert system to facilitate the scheduling of telemetry missions and the deconfliction of their frequencies. This system emphasizes the graphical manipulation of mission data and uses a genetic algorithm to search for an optimal set of mission frequencies. The second path is the development of a bidirectional command and control link to remotely control and configure the frequency of a telemetry link. This link uses the simple network management protocol (SNMP) over a wireless Internet Protocol (IP) network implemented with Digital Communications Network System (DCNS) units.

La technologie OFDMA (Orthogonal frequency division multiple access) a été adoptée par les systèmes de télécommunications de 4ème génération (4G) comme technique de transmission et d'accès multiple pour ses performances supérieures en termes d'efficacité spectrale. Dans ce type de systèmes, l'adaptation dynamique du débit en fonction de la qualité du canal CQI (Channel Quality Indicator) constitue une problématique de recherche d'actualité qui attire l'attention de plusieurs acteurs académiques et industriels. Ce problème d'adaptation dynamique est encore plus complexe à gérer dans des environnements multi-utilisateurs hétérogènes et à ressources limitées tels que les systèmes OFDMA comme WiMAX Mobile et Long-term Evolution (LTE). Dans cette thèse, nous nous intéressons au problème d'allocation de ressources de l'information de feedback relative au CQI dans le cadre de systèmes OFDMA multi-porteuses multi-utilisateurs. Dans le but de réduire la charge (overhead) du feedback, nous proposons une méthode de prédiction du CQI basée sur l'exploitation de la corrélation temporelle de ce dernier et d'une solution inter-couches. L'objectif est de trouver des schémas d'allocation de ressources adaptatifs respectant les contraintes de qualité de service (QoS) applicatives.Nous proposons en premier lieu un algorithme de réduction de feedback PBF (Prediction Based Feedack) qui permet à la station de base (BS) à prédire certaines occurrences du CQI en se basant sur l'algorithme des moindres carrés récursif RLS (Recursive least-square). Les résultats de simulation montrent que l'outil de prédiction du CQI réduit sensiblement l'overhead du feedback et améliore par conséquent le débit de la liaison montante. Nous proposons, par la suite, une version opportuniste de PBF pour atténuer les éventuels effets de sur et sous estimations liées à l'algorithme de prédiction. Dans ce mécanisme, nous exploitons les informations inter-couches pour améliorer les performances des mécanismes de feedbacks périodiques dont PBF fait partie. L'approche opportuniste améliore sensiblement les performances du système pour les cas de mobilité élevée comparés aux cas de faible mobilité.Dans un second temps, nous proposons une plateforme (FEREP : feedback resource allocation and prediction) basée sur une approche inter-couches. Implémentée au niveau de la station BS, FEREP intègre les fonctionnalités de prédiction, d'adaptation dynamique du CQI et d'ordonnancement des demandes de feedback. Elle comporte trois modules. Le module FWA (feedback window adaptation) gère dynamiquement la fenêtre de feedbacks de chaque station mobile (MS) en se basant sur les messages ARQ (Automatic Repeat Request) reçus qui reflètent l'état actuel des canaux respectifs. Le module PBFS (priority-based feedback scheduling) effectue ensuite l'ordonnancement des feedbacks en tenant compte de la taille de la fenêtre de feedback, du profil de l'utilisateur sous la contrainte de la limitation des ressources globales du systèmes réservées au feedback. Afin de choisir les paramètres de transmission MCS (modulation and coding schemes), le module PBF (prediction based feedback) est utilisé pour les utilisateurs dont le feedabck n'a pas pu être ordonnancé dans la trame courante. Les résultats de simulation ont montré un gain significatif des performances de FREREP en comparaison à un mécanisme de référence, en particulier, sous de fortes contraintes de limitation des ressources du feedback.Le protocole ARQ génère un accusé de réception uniquement si l'utilisateur est sélectionné par l'ordonnanceur pour envoyer des données sur la liaison descendante. Dans le cas où la fréquence d'ordonnancement des utilisateurs sur le lien descendant est réduite, les messages ARQ s'en trouvent également réduits, dégradant par conséquent les performances de la plateforme FEREP proposée ci-dessus. En effet, dans ce cas la signalisation ARQ devient insuffisante pour adapter efficacement la fenêtre de feedback de chaque utilisateur. Pour pallier à ce problème, nous proposons l'algorithme DCRA (dynamic CQI resource allocation) qui utilise deux modes d'estimation de la fenêtre de feedback. Le premier est un mode hors-ligne basé sur des études empiriques permettant d'estimer la fenêtre moyenne optimale de feedback en utilisant les profils applicatif et de mobilité de l'utilisateur. Notre analyse de performance par simulation montre que la fenêtre de feedback peut être estimée en fonction de la classe de service des utilisateurs et de leurs profils de mobilité pour un environnement cellulaire donné. Le second mode de fonctionnement de DCRA effectue une adaptation dynamique de la fenêtre en temps réel dans le cas où la signalisation ARQ est suffisante. Une étude comparative avec les mécanismes DFS (deterministic feedback scheduling) et OFS (opportunistic feedback scheduling), a montré que DCRA arrive à réaliser un meilleur gain en ressources montantes grâce à la réduction de l'overhead des feedbacks, sans pour autant trop dégrader le débit descendant des utilisateurs. Du point de vue des utilisateurs, DCRA améliore les contraintes de QoS tels que le taux de perte de paquets et réduit la consommation énergétique des terminaux grâce à la réduction de feedback<br>Orthogonal frequency division multiple access (OFDMA) technology has been adopted by 4th generation (a.k.a. 4G) telecommunication systems to achieve high system spectral efficiency. A crucial research issue is how to design adaptive channel quality indicator (CQI) feedback mechanisms so that the base station can use adaptive modulation and coding (AMC) techniques to adjust its data rate based on the channel condition. This problem is even more challenging in resource-limited and heterogeneous multiuser environments such as Mobile WiMAX, Long-term Evolution (LTE) networks. In this thesis, we consider CQI feedback resource allocation issue for multiuser multicarrier OFDMA systems. We exploit time-domain correlation for CQI prediction and cross-layer information to reduce feedback overhead for OFDMA systems. Our aim is find resource allocation schemes respecting the users QoS constraints.Our study begins with proposing prediction based feedback (PBF) which allows the base station to predict the CQI feedbacks based on recursive least-square (RLS) algorithm. We showed that it is useful to use channel prediction as a tool to reduce the feedback overhead and improve the uplink throughput. Then, we propose an opportunistic periodic feedback mechanism to mitigate the possible under and over estimation effects of CQI prediction. In this mechanism, we exploited the cross-layer information to enhance the performance of periodic feedback mechanisms. The opportunistic mechanism improves the system performance for high mobility cases compared to low mobility cases.For OFDMA systems with limited feedback resource, we propose an integrated cross-layer framework of feedback resource allocation and prediction (FEREP). The proposed framework, implemented at the BS side, is composed of three modules. The feedback window adaptation (FWA) module dynamically tunes the feedback window size for each mobile station based on the received ARQ (Automatic Repeat Request) messages that reflect the current channel condition. The priority-based feedback scheduling (PBFS) module then performs feedback allocation by taking into account the feedback window size, the user profile and the total system feedback budget. To choose adapted modulation and coding schemes (MCS), the prediction based feedback (PBF) module performs channel prediction by using recursive least square (RLS) algorithm for the user whose channel feedback has not been granted for schedule in current frame. Through extensive simulations, the proposed framework shows significant performance gain especially under stringent feedback budget constraint.ARQ protocol receives users acknowledgement only if the user is scheduled in the downlink. The reduction in users scheduling frequency also reduces the rate of ARQ hints and degrades the performance of above contributions. In this case, it is difficult to exploit the ARQ signal to adapt the feedback window for that user. To address this issue, we propose a cross-layer dynamic CQI resource allocation (DCRA) algorithm for multiuser multicarrier OFDMA systems. DCRA uses two modes for feedback window estimation. The first one is an off-line mode based on empirical studies to derive optimal average feedback window based on user application and mobility profile. Our experimental analysis shows that the feedback window can be averaged according to users service class and their mobility profile for a given cell environment. DCRA performs a realtime dynamic window adaptation if sufficient cross-layer hints are available from ARQ signaling. DCRA increases uplink resource by reducing feedback overhead without degrading downlink throughout significantly compared to deterministic feedback scheduling (DFS) and opportunistic feedback scheduling (OFS). From the users perspective, DCRA improves QoS constraints like packet loss rate and saves users power due to feedback reduction

La technologie OFDMA (Orthogonal frequency division multiple access) a été adoptée par les systèmes de télécommunications de 4ème génération (4G) comme technique de transmission et d'accès multiple pour ses performances supérieures en termes d'efficacité spectrale. Dans ce type de systèmes, l'adaptation dynamique du débit en fonction de la qualité du canal CQI (Channel Quality Indicator) constitue une problématique de recherche d'actualité qui attire l'attention de plusieurs acteurs académiques et industriels. Ce problème d'adaptation dynamique est encore plus complexe à gérer dans des environnements multi-utilisateurs hétérogènes et à ressources limitées tels que les systèmes OFDMA comme WiMAX Mobile et Long-term Evolution (LTE). Dans cette thèse, nous nous intéressons au problème d'allocation de ressources de l'information de feedback relative au CQI dans le cadre de systèmes OFDMA multi-porteuses multi-utilisateurs. Dans le but de réduire la charge (overhead) du feedback, nous proposons une méthode de prédiction du CQI basée sur l'exploitation de la corrélation temporelle de ce dernier et d'une solution inter-couches. L'objectif est de trouver des schémas d'allocation de ressources adaptatifs respectant les contraintes de qualité de service (QoS) applicatives.Nous proposons en premier lieu un algorithme de réduction de feedback PBF (Prediction Based Feedack) qui permet à la station de base (BS) à prédire certaines occurrences du CQI en se basant sur l'algorithme des moindres carrés récursif RLS (Recursive least-square). Les résultats de simulation montrent que l'outil de prédiction du CQI réduit sensiblement l'overhead du feedback et améliore par conséquent le débit de la liaison montante. Nous proposons, par la suite, une version opportuniste de PBF pour atténuer les éventuels effets de sur et sous estimations liées à l'algorithme de prédiction. Dans ce mécanisme, nous exploitons les informations inter-couches pour améliorer les performances des mécanismes de feedbacks périodiques dont PBF fait partie. L'approche opportuniste améliore sensiblement les performances du système pour les cas de mobilité élevée comparés aux cas de faible mobilité.Dans un second temps, nous proposons une plateforme (FEREP : feedback resource allocation and prediction) basée sur une approche inter-couches. Implémentée au niveau de la station BS, FEREP intègre les fonctionnalités de prédiction, d'adaptation dynamique du CQI et d'ordonnancement des demandes de feedback. Elle comporte trois modules. Le module FWA (feedback window adaptation) gère dynamiquement la fenêtre de feedbacks de chaque station mobile (MS) en se basant sur les messages ARQ (Automatic Repeat Request) reçus qui reflètent l'état actuel des canaux respectifs. Le module PBFS (priority-based feedback scheduling) effectue ensuite l'ordonnancement des feedbacks en tenant compte de la taille de la fenêtre de feedback, du profil de l'utilisateur sous la contrainte de la limitation des ressources globales du systèmes réservées au feedback. Afin de choisir les paramètres de transmission MCS (modulation and coding schemes), le module PBF (prediction based feedback) est utilisé pour les utilisateurs dont le feedabck n'a pas pu être ordonnancé dans la trame courante. Les résultats de simulation ont montré un gain significatif des performances de FREREP en comparaison à un mécanisme de référence, en particulier, sous de fortes contraintes de limitation des ressources du feedback.Le protocole ARQ génère un accusé de réception uniquement si l'utilisateur est sélectionné par l'ordonnanceur pour envoyer des données sur la liaison descendante. Dans le cas où la fréquence d'ordonnancement des utilisateurs sur le lien descendant est réduite, les messages ARQ s'en trouvent également réduits, dégradant par conséquent les performances de la plateforme FEREP proposée ci-dessus. En effet, dans ce cas la signalisation ARQ devient insuffisante pour adapter efficacement la fenêtre de feedback de chaque utilisateur. Pour pallier à ce problème, nous proposons l'algorithme DCRA (dynamic CQI resource allocation) qui utilise deux modes d'estimation de la fenêtre de feedback. Le premier est un mode hors-ligne basé sur des études empiriques permettant d'estimer la fenêtre moyenne optimale de feedback en utilisant les profils applicatif et de mobilité de l'utilisateur. Notre analyse de performance par simulation montre que la fenêtre de feedback peut être estimée en fonction de la classe de service des utilisateurs et de leurs profils de mobilité pour un environnement cellulaire donné. Le second mode de fonctionnement de DCRA effectue une adaptation dynamique de la fenêtre en temps réel dans le cas où la signalisation ARQ est suffisante. Une étude comparative avec les mécanismes DFS (deterministic feedback scheduling) et OFS (opportunistic feedback scheduling), a montré que DCRA arrive à réaliser un meilleur gain en ressources montantes grâce à la réduction de l'overhead des feedbacks, sans pour autant trop dégrader le débit descendant des utilisateurs. Du point de vue des utilisateurs, DCRA améliore les contraintes de QoS tels que le taux de perte de paquets et réduit la consommation énergétique des terminaux grâce à la réduction de feedback.

L’efficacité de la grande majorité des outils utilisés pour le Traitement Automatique des Langues Naturelles (TALN) dépend directement ou indirectement des ressources linguistiques informatisées sur lesquels ils reposent. Pour des langues internationalement employées telles que le français ou l’espagnol, bien des ressources de référence sont encore dans un état précaire de développement. Pour d’autres langues ayant une communauté moins importante, ces ressources sont souvent inexistantes. Cette situation est la conséquence directe des ambigüités et des irrégularités des langues naturelles. Ces dernières rendent leur formalisation complexe, leur description manuelle fastidieuse et leur acquisition automatisée difficile. De nos jours, pour les aspects linguistiques ayant des formalismes de description consensuels, la principale limitation à la création des ressources linguistiques est le coût humain prohibitif induit par leur création et amélioration manuelle. Comme le formalise la loi de Zipf, améliorer la qualité et la couverture d’une ressource linguistique devient toujours plus laborieux lorsque l’on compara les efforts investis aux améliorations obtenues. La difficulté est donc moins de savoir comment décrire l’aspect linguistique d’une langue que d’en réaliser une description dont la couverture et la qualité répondent aux besoins d’applications performantes. Construire de telles ressources requiert donc des années d’efforts constants débouchant trop souvent sur des résultats d’une qualité relative et d’une visibilité limitée. L’acquisition et la correction rapides et efficaces de ressources linguistiques sont donc des problèmes peu résolus et d’une importante capitale pour les développement dans le domaine du TALN. Dans ce contexte, mes recherches ont pour but premier de faciliter la production de ressources linguistiques symboliques ayant trait à l’analyse syntaxique. Elles s’inscrivent dans un projet, appelé Victoria, dont l’objectif est de développer un ensemble de techniques, d’outils et de stratégies pour l’acquisition et la correction de règles morphologiques, de lexiques morphosyntaxiques et de grammaires lexicalisées. L’application pratique de ces développements nous a permis de créer et/ou d’améliorer des ressources linguistiques pour le français, l’espagnol et le galicien. Plus particulièrement, mes efforts se sont concentrés sur : des stratégies pratiques pour minimiser les efforts nécessaires à la création et l’amélioration de ressources linguistiques ; l’acquisition automatique des règles morphologiques d’une langue à morphologie concaténative ; la correction semi-automatique de lexiques morpho-syntaxiques à large couverture.

High variability in rainfall together with high evaporative demand creates severe constraints for crop growth and yields in semiarid environment where sustainable food security is needed.  Crop research has, therefore, to focus on sustaining the competitiveness of production in these environments where optimal root architecture can be important in determining uptake and resource use efficiency of water and nutrients. The aim of this thesis was to identify variation in genetic by environment interaction amongst wheat cultivars in root system architecture and to establish on how it relates to water and nutrient acquisition and drought tolerance/resistance. Initial laboratory studies revealed variation in rooting strategies amongst cultivars.  This was followed by two soil bed studies and one field study, which investigated the association of rooting strategies with WUE, NUE and crop performance in the absence and presence of moisture stress (wet and dry) and of nitrogen (0 and 60 kg N ha^-1). Laboratory, soil-bed and field trials were conducted to test the hypothesis that selection of optimum rooting traits would improve WUE, NUE and production of wheat cultivars in dry semi-arid environments.  Results showed that wheat cultivars have two distinct rooting strategies, one with large root systems and fast extension and the other with small root systems and slow extension.  The enhanced resource acquisition strategy associated with large, rapidly extending roots was shown to be successful in all environments.  It resulted in fast earlier plant vigour, higher WUE, NUE and DM yield.

I proposed that both Bruner's (1963) idea of the spiral curriculum and Yenawine's (1992) theories of teaching for visual literacy in the museum set the stage for significant learning for students when used together. If school teachers lay a foundation of knowledge about a museum object, especially through museum resources, then the student may transform and apply this 'prior knowledge' (explicit memories from the classroom) while on the museum visit tour. When docents utilize Yenawine's (1992) methods toward the goal of visual literacy, the semantic knowledge of the classroom is then fused with museum learning, building stronger memories and facilitating deeper understanding as students learn about museum objects. This research explored the correlation of these two theories in a qualitative manner based on observations of actual museum visit preparation in classrooms in Casper, Wyoming, and how it related to a museum tour at the Nicolaysen Art Museum and Discovery Center. The research revealed that conditions do exist within the community that would facilitate Bruner's (1963) idea of a learning spiral, yet not in the manner envisioned. The observed conditions toward a spiral was accomplished through the participant teachers relating the museum exhibit to their operational curriculum in a variety of curricular areas, such as language arts and science, when docents related the tour to classroom learning, and not through museum resources or Yenawine's (1992) methods toward increasing visual literacy, as was previously considered.

Causes and consequences of woody encroachment into grass dominated systems have been widely studied, however functional mechanisms which promote encroachment are largely unknown. Many expansive woody species are shrubs with rhizobial or actinorhizal N-fixing symbiotic associations. Morella cerifera L. (Myricaceae) is an actinorhizal N-fixing shrub which rapidly expands into grasslands on the barrier islands off the coast of Virginia, USA. The objective of this research was to determine physiological drivers of woody encroachment resulting in increased woody cover of M. cerifera on Southeastern, US barrier islands. Variations in physiology and resource use efficiencies (RUE) of M. cerifera and co-occurring shrubs were determined, and edaphic characteristics beneath shrub thicket canopies and in open areas were quantified as indications of resource availability. Analysis of dune vegetation and soils showed severe freshwater limitation and reduced plant height of dune forbs suggesting dunes represent an upper elevational boundary for M. cerifera distribution. Soil N availability was higher beneath shrubs compared to open areas, and both physiology and isotope effects showed facilitation of the non-fixing shrub, Baccharis halimifolia, by M. cerifera which may lead to increased rates of woody encroachment as B. halimifolia colonizes expanding thicket edges. Morella cerifera and other N-fixers had higher %refixation within stems which resulted in higher carbon use efficiency (CUE) and water use efficiency of N-fixing shrubs compared to non-fixers. Results of an N-fertilization experiment suggest B. halimifolia has higher dependence on and demand for soil nutrients compared to M. cerifera. Morella cerifera showed no signs of resource deficiency or reduced physiological capacity even at 0 ppm total Nsoil. Morella cerifera transitioned from utilizing solely fixation derived N to soil N as N concentrations increased providing another mechanism leading to increased CUE and, indirectly, overall RUE. In summary greater RUE, lower resource demand, and greater resource availability for M. cerifera compared to co-occurring shrubs may result from symbiotic root associations with bacteria and fungi. While expansion of M. cerifera thickets is limited to lower elevational interdunal depressions, expansion may continue and result in increased rates of woody encroachment through facilitation of co-occurring shrubs.

Research question: What initiatives does Lidl Sweden implement in the area of environmental sustainability?                          Purpose: The purpose of this research is to investigate what initiatives Lidl has developed and how the company implemented its corporate social responsibility in the direction of environmental sustainability. The purpose is also to compare the company’s activities with the guidelines of the EU Environment Commission and theoretical frameworks developed by previous research, and, as the result, to provide recommendations to the Lidl management. As well the purpose is to review the general improvement patterns within the food retail industry. Method: The research is made by using a qualitative method with a deductive approach. In order to present quality information in the study, a case design was chosen. The empirical analysis includes four interview transcriptions, secondary data and documentation, as well as a comparison to the theoretical concepts in the descriptive analysis. Conclusion: The responsibility and awareness of the improvement of the environmental sustainability is vital in the food retail industry. Indeed, it was found that aspects such as product and supplier’s control, the use of resources, transportation and distribution, as well as waste management and information communication to the employees and customers are considered as important aspects of the contribution for the environmental impact reduction. Lidl Sweden has developed and implemented some initiatives towards environmental sustainability, as well regarding the corporate social responsibility. However, there are some suggested actions that can be taken in order to excel the development.

У роботі розглядаються теоретичні основи формування та використання банківських ресурсів; досліджені поняття, структура та джерела формування банківських ресурсів; надана характеристика ресурсної політики як інструменту управління процесом залучення фінансових ресурсів банку; розглянуті методи оцінки ефективності використання банківських ресурсів. Проаналізовано сучасні аспекти формування ресурсної бази банку в сучасних умовах; надана оцінка достатності власного капіталу банку; досліджений склад та динаміки запозичених коштів банку; зроблений аналіз депозитного портфелю як джерела фінансових ресурсів банку. Запропоновано напрями ефективного використання фінансових ресурсів банку; надана комплексна оцінка оптимального використання депозитних та недепозитних джерел банківських ресурсів; зроблено моделювання впливу факторів клієнтського капіталу на доходи банків.<br>Diploma thesis deals with the theoretical foundations of the formation and use of banking resources; the concept, structure and sources of the formation of banking resources are investigated; the characteristic of the resource policy as a tool for managing the process of attracting financial resources of the bank is given; the methods of assessing the efficiency of using bank resources are considered. The modern aspects of the formation of the resource base of the bank in modern conditions are analyzed; an assessment of the bank's equity adequacy is provided; studied the composition and dynamics of borrowed funds of the bank; the analysis of the deposit portfolio as a source of financial resources of the bank is made. The directions of effective use of financial resources of the bank are offered; a comprehensive assessment of the optimal use of deposit and non-deposit sources of bank resources; modeling of influence of factors of the client capital on incomes of banks is made.

Mestrado em Economia e Gestão de Ciência, Tecnologia e Inovação<br>Apesar de ser um sector com elevado potencial de provocar crescimento económico, a I&D não está imune à necessidade de se avaliar o papel de financiador do Estado. Neste sentido o presente estudo exploratório visa avaliar a eficiência da utilização de recursos públicos no sistema de produção de conhecimento através da metodologia não paramétrica DEA, com posterior bootstrap para obter indicadores de eficiência imunes a enviesamento derivados da amostra. Posteriormente analisa-se o impacto de variáveis exógenas através de análise de correlação e regressão linear e termina-se com uma análise de clusters. São utilizados como input indicadores de despesa em I&D e investigadores do sector governamental e Ensino Superior, e como outputs, o número de pedidos de patentes PCT, e de artigos científicos e tecnológicos e os royalties e receitas de licenças recebidas. Os países mais eficientes entre 1998 e 2007, antes do bootstrap, são os EUA, a China e a Irlanda.<br>Even though it is one of the most reliable sector to induce economic growth, R&D is not immune to the need to evaluate the State’s role as financier. In this sense, the present exploratory study aims to evaluate the efficiency from the use of public resources in the production of new knowledge through the non-parametric methodology of DEA, with posterior bootstrap analysis to obtain efficiency indicators exempt from sampling bias. Furthermore, the impact of exogenous variables through the correlation analysis and linear regression is analyzed, culminating with a cluster analysis. Considered inputs are R&D expense and researchers from the Governmental and High Education sectors. Outputs rely on PCT patent appliances, scientific and technological articles published, and royalties and license revenues received. The most efficient countries from 1998 to 2007, prior to the bootstrap analysis, are the USA, China and Ireland.

Le but principal des réseaux mesh sans fil (Wireless Mesh Networks-WMNs) est de fournir une dorsale de communication pour un grand nombre d'utilisateurs, car les WMNs doivent supporter un trafic énorme. Dans cette thèse, nous visons la maximisation d'utilisation et la répartition équitable de la bande passante dans les WMNs. Nous considérons deux environnements : WMN utilisant la norme IEEE 802.11 MAC, qui est caractérisée par son déploiement répandu et peu cher, et WMN utilisant les antennes directionnelles, qui représentent une technologie clé pour la réutilisation spatiale dans les réseaux sans fil. Pour les WMMs basés sur IEEE 802.11, nous concevons NICC, un protocole de contrôle de congestion qui reconnaît la congestion comme un problème lié au voisinage, et non pas au lien. NICC gère la congestion par une collaboration entre les nœuds d’un voisinage sans fil. En faisant usage de certains champs sous-exploités dans l'en-tête IEEE 802.11, NICC fournit un retour de congestion implicite et multi-bit. Ceci assure un contrôle précis du trafic sans affecter la bande passante. Pour les WMNs utilisant les antennes directionnelles, nous concevons FreeDMAC, un protocole MAC basé sur la technologie TDMA. FreeDMAC garantit que chaque nœud est conscient de toutes les transmissions dans son voisinage, ce qui évite les problèmes MAC causés par les antennes directionnelles, et ainsi, améliore l'utilisation de la bande passante. En outre, FreeDMAC est capable de fournir deux niveaux d’équité: équité entre les liens et équité entre les flux<br>The main purpose of Wireless Mesh Networks (WMNs) is to provide a communication backbone for a high number of end-users, thus WMNs have to support heavy traffic load. In this thesis, we intend to maximize utilization and achieve fair allocation of the bandwidth resources in WMNs. We consider two WMN environments: WMN using the IEEE 802.11 MAC standard, which is characterized by its cheap devices and widespread deployment, and WMN using directional antennas, which are emerged as an attractive technology to enhance the spatial reusability in wireless networks. For WMM based on IEEE 802.11, we design NICC, a congestion control scheme that recognizes congestion as neighborhood-related problem, and not a link-based one. Indeed, complex interference among neighboring nodes is the main starvation cause in WMNs. Therefore, NICC handles congestion using mutual cooperation within a wireless neighborhood. NICC makes use of some underexploited fields in the IEEE 802.11frame header in order to provide an implicit multi-bit congestion feedback, and thus ensure accurate rate control without generating overhead, making efficient use of bandwidth. For WMN with directional antennas, we design FreeDMAC, a TDMA-based MAC scheme with contention-free scheduling. FreeDMAC guarantees that each node is aware of all ongoing transmissions in its neighborhood, and thus avoids directional-related problems such as deafness, making efficient use of bandwidth. Moreover, FreeDMAC presents a link-slot assignment that provides two levels of fairness: Per-link and per-flow fairness

In the past decades, linear programming (LP) has been successfully used to develop approximation algorithms for various optimization problems. In particular, the so-called assignment LP has lead to substantial progress for various allocation problems, including scheduling unrelated parallel machines. However, we have reached its limits for many problems, since the best-known approximation algorithms match the integrality gap of the assignment LP for these problems. The natural question is then whether a different LP formulation can lead to better algorithms. We answer this question positively for variants of two allocation problems: max-min fair allocation and maximum budgeted allocation. This is achieved by using a more powerful LP formulation called the configuration LP that has an exponential number of variables, but can be approximated in polynomial time. The restricted max-min fair allocation problem, also known as the restricted Santa Claus problem, is one of few problems that have a better polynomial estimation algorithm than approximation algorithm. An estimation algorithm estimates the value of the optimal solution, but is not necessarily able to find the optimal solution. The configuration LP can be used to estimate the optimal value within a factor of 1/(4+ɛ) for any ɛ&gt;0, but it is only known how to efficiently find a solution achieving this value in exponential time. We give an approximation algorithm with the same approximation ratio but improve the running time to quasi-polynomial: n^O(log n). Our techniques also have the interesting property that although we use the rather complex configuration LP in the analysis, we never actually solve it and therefore the resulting algorithm is purely combinatorial. For the maximum budgeted allocation (MBA) the integrality gap of the assignment LP is exactly 3/4. We prove that the integrality gap of the configuration LP is strictly better than 3/4 and provide corresponding polynomial time rounding algorithms for two variants of the problem: the restricted MBA and the graph MBA. Finally, we improve the best-known upper bound on the integrality gap for the general case from 0.833 to 0.828 and also show hardness of approximation results for both variants studied.<br>Under de senaste decennierna har linjärprogrammering (LP) framgångsrikt använts för att utveckla approximeringsalgoritmer. I synnerhet har det så kallade tilldelnings-LP lett till betydande framsteg för olika allokeringsproblem, som scheduling unrelated parallel machines. Vi verkar dock ha nått dess gräns, eftersom de bästa approximeringsalgoritmerna har samma kvalitet som heltalsgapet för dessa problem. Den naturliga frågan är då om någon annan LP-formulering kan leda till bättre algoritmer. Vi besvarar denna fråga positivt för varianter av två fördelningsproblem: max-min fair allocation och maximal budgeted allocation. Vi använder en mer kraftfull LP-formulering som kallas konfigurations-LP och har ett exponentiellt antal variabler men kan approximeras i polynomisk tid. Problemet restricted max-min fair allocation, som är även känt som restricted Santa Claus problem, är ett av få problem som har en bättre polynomisk värderingsalgoritm än approximeringsalgoritm. En värderingsalgoritm approximerar det optimala värdet, men hittar inte nödvändigtvis den optimala lösningen. Konfigurations-LP kan användas för att approximera det optimala värdet inom en faktor 1 / (4 + ɛ) för något ɛ &gt; 0, men man vet bara hur man hittar en lösning med sådan kvalitet i exponentiellt tid. Vi ger en approximeringsalgoritm med samma approximeringskvalitet men förbättrar tidskomplexitet till kvasipolynomisk: n^O(log n). Våra tekniker har också den intressanta egenskapen att även om vi använder det ganska komplext konfigurations-LP:t i analysen, löser vi aldrig det och vår algoritm är rent kombinatorisk. För maximal budgeted allocation (MBA) är heltalsgapet av tilldelnings-LP:et är precis 3/4. Vi bevisar att heltalsgapet av konfiguration-LP är strikt bättre än 3/4 och vi ger en motsvarande polynomisk avrundningsalgoritm för två varianter av problemet: restricted MBA och graph MBA. Slutligen förbättrar vi den bäst kända övre gränsen på heltalsgapet för det allmänna fallet från 0.833 till 0.828 samt ger approximeringssvårighetsresultat för båda två studerade varianter.<br><p>QC 20150305</p><br>ERC APPROXNP 226203

Under Mediterranean environments water and nitrogen (N) are considered the two factors most strongly limiting crop productivity. Wheat (bread and durum) and barley are the main crops grown in dryland Mediterranean environments. Within the Mediterranean basin, wheat is usually cultivated in rotations with other crops under relatively humid zones while barley is sown as a monoculture in the driest zones. Reasons behind barley monoculture are based on an hypothetical barley yield advantage over wheat under stressed environments. However, information about direct comparison between wheat (bread or durum) and barley is not abundant for the Mediterranean basin (nor for other Mediterranean regions). Neither grain yield nor biomass production, water use, nitrogen use or their use efficiency have been compared for the three species to justify the preference of one of them in monoculture in the more scarce resource availability environments. <br/>The main objective of the present thesis was to assess the response of wheat (bread and durum) and barley in terms of productivity to different water and nitrogen availabilities within the Mediterranean conditions of dryland cereal regions of Catalonia. Within the main objective two specific objectives were formulated (i) to provide empirical support to the generalized hypothesis of a better performance of barley than wheat under stress conditions, and (ii) to analyze if N fertilization could be a management tool to increase grain yield under stressful Mediterranean conditions for small grain cereals (in cases in which soil N were low). To fulfil the objectives data taken from a literature revision, and historical and regional data were analysed combined with those from five field experiments that were carried-out using different combinations of water and N availabilities for a typical well-adapted and representative cultivar of bread wheat, durum wheat and barley during 2003/04 to 2006/07 growing seasons in a typical dryland region of Catalonia where barley represent c. 80 % of the total cereal acreage. <br/>Across all the experimental conditions grain yield of the three species varied widely from c. 1 to 10 Mg ha-1. Under the driest and poorest yielding conditions barley presented similar yields to wheat (bread and durum) using the experimental data, but also using the bibliographic, historical and regional data, indicating an unjustified barley monoculture in terms of productivity. Despite similar yield between durum wheat and barley a lower stability in grain weight was observed for the case of durum wheat. Neither water use or N use or their use efficiencies supported the hypothesised advantage of barley over wheat across the driest experimental conditions. Water availability and N fertilization modified grain yield, biomass and resource use efficiency. In the present thesis, it was evidenced with realistic field data for the first time that of the degree of co-limitation between factors (N and water in this case) may affect yields as well as water use efficiency of small grain cereals, which had been previously proposed but using simulation models for wheat production in Australia.

Cerrado is the second largest Brazilian biome and originally corresponded to 24% of the national territory, and since the 1970´s has been under agriculture and cattle activities. Soybean and maize are two of the most important grain-crops found in this region, with an estimated production of approximately 223 millions of tons in the Brazilian 2016/17 harvest. Changes in soil physical properties due to soil management affect productivity. Possible changes in climatic variables may also affect agricultural productivity, either per unit area (land productivity) or per unit of water volume (water productivity). One option for studying the relation between land and water productivity and how they are affected by soil hydraulic properties and climatic factors is by using an agro-hydrological model. In this study, the aim was to quantify aspects of the soil water balance and to make estimates of land and water productivity for soybean in a clay soil and maize in a medium texture in the Cerrado region using SWAP simulations for different irrigation strategies. Effects on agricultural productivity of a climatic prevision with increasing the air temperature and rainfall reduction for the years 2016-2040 were also simulated. Results show that an increase of soil porosity, resulting from a conservation tillage management, leads to a higher infiltration capacity and is shown to increase land and water productivity, when associated to irrigation scenarios. Higher water productivities were observed with only supplementary irrigation. Predicted climate changes will lead to a decrease of approximately 20% by the end of the years 2016-2040 in land productivity, under rainfed conditions.<br>O Cerrado é o segundo maior bioma brasileiro que originalmente, correspondia a 24% do território nacional, e desde os anos 1970 tem sido utilizado para atividades ligadas à agricultura e pecuária. Soja e milho são duas das mais importantes culturas graníferas encontradas nesta região, com uma estimativa de produtividade de aproximadamente 223 milhoes de toneladas na safra brasileira de 2016/17. Mudanças nas propriedades físicas do solo devido ao manejo do solo afetam a produtividade agrícola. Possíveis mudanças de variáveis climáticas também poderão afetar a produtividade agrícola, tanto por unidade de área (produtividade de terra) ou por unidade de volume de água (produtividade de água). Uma opção para estudar as relações entre a produtividade de água e de terra e como elas são afetadas pelas propriedades hidraulicas do solo e pelos fatores climáticos é pela utilização de um modelo agro-hidrológico. Neste trabalho, o objetivo foi quantificar os aspectos do balanço hídrico do solo e realizar estimativas da produtividade de água e de terra para soja em um solo argiloso e para milho em um solo de textura média, na região do Cerrado, utilizando simulações com o modelo SWAP para diferentes manejos de irrigação. Os efeitos na produtividade agrícola de uma previsão climática com aumento da temperatura do ar e redução da precipitação para os anos 2016-2040 foram também simulados. Os resultados mostram que um aumento na porosidade do solo, resultante de um manejo conservacionista do solo, leva a uma maior infiltração e resulta num aumento na produtividade da terra e da água, quando associado a cenários de irrigação. As maiores produtividades da água foram observadas com irrigação suplementar. As mudanças climáticas previstas levarão a uma diminuição de aproximadamente 20% na produtividade da terra ao final dos anos 2016-2040, em áreas não irrigadas.

Meeting the ever-growing global energy demand while reducing carbon emissions is one of the most prominent challenges of our era. In this context, efficient control of an operation, service or production process is a key tool to achieve this goal. While there are many opportunities for efficient control within the energy sustainability agenda, this work focuses on domestic space heating systems and intermittent energy resources. This is because in many countries, such as the UK and the US, the domestic sector accounts for more than 20% of the total energy consumption and over 40% of this share is related to space heating. In addition, in recent years, an increasing number of intermittent energy resources, such as photovoltaic systems and wind turbine generators are being integrated into the grid. As such, efficient control of domestic space heating systems and intermittent energy resources can lead to a major reduction in energy consumption and the corresponding CO2 emission. In more detail, domestic space heating automation systems (DHASs) aim to optimize the control process of domestic space heating systems with minimum user-input. Moreover, in the case of electricity-based heating, such systems can also incorporate economic control to exploit the energy buffer that heating loads provide in order to shift the heating consumption according to financial incentives, such as variable electricity import tariffs and/or the availability of cheap electricity coming from house-integrated intermittent energy resources. In the latter case, the financial benefits of economic control can be further amplified in domestic coalitions where a number of houses share their energy generation to minimize the collective energy imported from the grid. Against this background, the first main strand of work in this thesis is to develop a new DHAS, AdaHeat, that overcomes limitations of previous approaches regarding: (i) their efficiency in dealing with the thermal dynamics of houses, (ii) their efficiency in dealing with the inherent uncertainty of the occupancy schedule in domestic settings, (iii) their usability and effectiveness in meeting the user preferences, (iv) their ability to work in conjunction with a diverse range of heating systems, and (v) their ability to efficiently consider economic control in the case of electricity-based heating, exploiting also, for the first time, the aforementioned coalition potential. The backbone of AdaHeat is an adaptive model predictive control approach along with a new general heating schedule planning algorithm based on dynamic programming. In the case of economic control in the presence of house-integrated intermittent energy resources, our planning approach relies on stochastic predictions of the shared intermittent energy resource power output. To this end, we also develop a new adaptive site-specific calibration technique to improve such predictions based on Gaussian process modeling. We present thorough evaluation of the proposed system, and show its effectiveness in terms of Pareto efficiency and usability criteria against state-of-the-art DHASs. We also show that collective economic control, in the presence of house-integrated IERs, can improve heating cost-efficiency by up to 60%, compared to independent economic control, and even more when compared to no economic control. The second strand of work is concerned with increasing the efficiency of intermittent energy resources themselves, through efficient control. In particular, specifically for photovoltaic systems, solar tracking can be used to orient the system towards the greatest possible levels of incoming solar irradiance. This can increase the power output of a photovoltaic system by up to 100%. However, current solar tracking techniques suffer from several drawbacks: (i) they usually do not consider the forecasted or prevailing weather conditions; even when they do, they (ii) rely on complex closed-loop controllers and sophisticated instruments; and (iii) typically, they do not take the energy consumption of the trackers into account. As such, in this work, we propose PreST; a novel, low-cost and generic solar tracking approach that overcomes the above limitations, utilizing optimal control (proposed for the first time for solar tracking). In particular, our approach is able to calculate appropriate trajectories for efficient and effective day-ahead (predictive) solar tracking, based on available weather forecasts (that can come from on-line providers for free). To this end, we propose a new approximating policy iteration algorithm, suitable for large Markov decision processes, and a novel and generic solar tracking consumption model. Our simulations show that our approach can increase the power output of a photovoltaic system considerably, when compared to standard solar tracking techniques, that can lead to significant monetary gains. As outlined above, apart from their great share in contemporary economies, both domestic space heating systems and intermittent energy resources provide considerable opportunities for energy efficient improvements through efficient control. In this work we exploit this potential and propose respective systems that improve their independent, as well as their interaction, efficiency. This can considerably reduce the respective energy consumption and the corresponding CO2 emission towards fulfilling our goal for an energy sustainable future.

Cette thèse présente des méthodes pour améliorer l'analyse syntaxique probabiliste en dépendances. Nous employons l'analyse à base de transitions avec une modélisation effectuée par des machines à vecteurs supports (Cortes and Vapnik, 1995), et nos expériences sont réalisées sur le français. L'analyse a base de transitions est rapide, de par la faible complexité des algorithmes sous-jacents, eux mêmes fondés sur une optimisation locale des décisions d'attachement. Ainsi notre premier fil directeur est d'élargir le contexte syntaxique utilisé. Partant du système de transitions arc-eager (Nivre, 2008), nous proposons une variante qui considère simultanément plusieurs gouverneurs candidats pour les attachements à droite. Nous testons aussi la correction des analyses, inspirée par Hall and Novâk (2005), qui révise chaque attachement en choisissant parmi plusieurs gouverneurs alternatifs dans le voisinage syntaxique. Nos approches i améliorent légèrement la précision globale ainsi que celles de l'attachement des groupes prépositionnels et de la coordination. Notre deuxième fil explore des approches semi-supervisées. Nous testons l'auto-entrainement avec un analyseur en deux étapes, basé sur McClosky et al. (2006), pour le domaine journalistique ainsi que pour l'adaptation au domaine médical. Nous passons ensuite à la modélisation lexicale à base de corpus, avec des classes lexicales généralisées pour réduire la dispersion des données, et des préférences lexicales de l'attachement des groupes prépositionnels pour aider à la désambiguïsation. Nos approches améliorent, dans certains cas, la précision et la couverture de l'analyseur, sans augmenter sa complexité théorique<br>This thesis explores ways to improve the accuracy and coverage of efficient statistical dependency parsing. We employ transition-based parsing with models learned using Support Vector Machines (Cortes and Vapnik, 1995), and our experiments are carried out on French. Transition-based parsing is very fast due to the computational efficiency of its underlying algorithms, which are based on a local optimization of attachment décisions. Our first research thretd is thus to increase thé syntactic context used. From the arc-eager transition System (Nivre, 2008) we propose a variant that simultaneously considers multiple candidate governors for right-directed attachments. We also test parse correction, inspired by Hall and Novâk (2005), which revises each attachment in a parse by considering multiple alternative governors in the local syntactic neighborhood. We find that multiple-candidate approaches slightly improve parsing accuracy overall as well as for prepositional phrase attachment and coordination, two linguistic phenomena that exhibit high syntactic ambiguity. Our second research thread explores semi-supervised approaches for improving parsing accuracy and coverage. We test self-training within the journalistic domain as well as for adaptation to the medical domain, using a two-stage parsing approach based on that of McClosky et al. (2006). We then turn to lexical modeling over a large corpus: we model generalized lexical classes to reduce data sparseness, and prepositional phrase attachment préférence to improve disambiguation. We find that semi-supervised approaches can sometimes improve parsing accuracy and coverage, without increasing time complexity