Network-wide assessment of 4D trajectory adjustments using an agent-based model

This paper presents results from the SESAR ER3 Domino project. It focuses on an ECAC-wide assessment of two 4D-adjustment mechanisms, implemented separately and conjointly. These reflect flight behaviour en-route and at-gate, optimising given (cost) objective functions. New metrics designed to capture network effects are used to analyse the results of a microscopic, agent based model. The results show that some implementations of the mechanisms allow the protection of the network from ‘domino’ effects. Airlines focusing on costs may trigger additional side-effects on passengers, displaying, in some instances, clear trade-offs between passenger- and flight-centric metrics

Real-time optimization-based control and estimation for dielectrophoretic micromanipulation

Tato diplomová práce se zabývá několika tématy souvisejícími s mikromanipulací pomocí dielektroforézy (DEP). V práci je nejprve popsána nově vyvinutá metoda pro odhadování polohy mikročástic v reálném čase. Metoda byla i implementována a otestována v laboratorních experimentech. Je založena na dvou-paprskovém osvětlení a bezčočkové digitální holografii a jako taková potřebuje ke své funkci jen velmi jednoduchý, levný a kompaktní hardware. Dále, jelikož pro účely na modelu založeného řízení polohy mikročástic je nutné mít k dispozici jednoduchý ale dostatečně přesný model svazující napětí na mikroelektrodách s vygenerovanou DEP sílou, v předložené práci je takový model odvozen pomocí aparátu Greenových funkcí. V poslední části se práce zabývá problémem určení napětí na mikroelektrodách tak, aby vytvořená DEP síla splňovala požadavky vyšších úrovní řídicího systému. V práci je zdokumentována analýza tohoto problému a několik nových metod jeho řešení. Tyto využívají výsledků pro tzv. numerický obor matice a semidefinitní programování.This diploma thesis focuses on several problems related to micromanipulation based on dielectrophoresis (DEP). First, a new real-time position estimation method for microparticles was designed, implemented and tested in experiments. The method is based on twin-beams illumination and lensless digital holography. As such, it only needs a very simple, cheap and compact hardware. Second, in order to pursue a model-based control design strategy for positioning the microparticles, a simple yet accurate mathematical model relating the voltages applied to the microelectrodes with the generated DEP force is needed. In this thesis, such a model is derived within the framework of Green's functions. Third, the computational problem of determining the voltages to be applied to the microelectrodes in order to establish the required DEP force is analyzed and several algorithms solving the problem are introduced. These invoke some linear-algebraic concepts from the numerical range (or field of values) of a complex matrix and semidefinite programing

Strategic allocation of flight plans in air traffic management: an evolutionary point of view

We present a simplified model of the strategic allocation of trajectories in a generic airspace for commercial flights. In this model, two types of companies, characterised by different cost functions and different strategies, compete for the allocation of trajectories in the airspace. With an analytical model and numerical simulations, we show that the relative advantage of the two populations -- companies -- depends on external factors like traffic demand as well as on the composition of the population. We show that there exists a stable equilibrium state which depends on the traffic demand. We also show that the equilibrium solution is not the optimal at the global level, but rather that it tends to favour one of the two business models -- the archetype for low-cost companies. Finally, linking the cost of allocated flights with the fitness of a company, we study the evolutionary dynamics of the system, investigating the fluctuations of population composition around the equilibrium and the speed of convergence towards it. We prove that in the presence of noise due to finite populations, the equilibrium point is shifted and is reached more slowly

Fiscal policy challenges in oil-exporting countries – a review of key issues.

Fiscal policy choices have a particularly significant impact on economic performance in oil-exporting countries, owing to the importance of the oil sector in the economy and the fact that in most countries oil revenues accrue to the government. At the same time, fiscal policy in oil-centred economies s facing specific challenges, both in the long run, as regards intergenerational equity and fiscal sustainability, and in the short run, as regards macroeconomic stabilisation and fiscal planning. Institutional responses to the specific fiscal challenges in oil-exporting countries involve conservative oil price assumptions in the budget, the establishment of oil stabilisation and savings funds and fiscal rules. Fiscal policy in most oil-exporting countries has been expansionary over the past years in the wake of high oil prices. Fiscal expansion has added to inflationary pressure, and monetary policy has been constrained in tackling inflation as a result of prevailing exchange rate regimes. While, in this context, fiscal policy is the major tool for macroeconomic stabilisation, it has faced competing objectives and considerations. Cyclical considerations would have warranted fiscal restraint, but, in times of high oil prices, pressures to increase public spending have been mounting. Such pressures stem from primarily distribution-related considerations, development-related spending needs (e.g. in the areas of physical and social infrastructure) and international considerations in the context of, for example, global imbalances. The sharp fall in oil prices since mid-2008 has brought to the fore a different question – whether oil exporters can sustain spending levels reached in previous years. JEL Classification: E62, E63, H30, H60, Q32, Q38.Fiscal policy, oil-exporting countries, inflation, global imbalances.

Fiscal policy in Mediterranean countries – developments, structures and implications for monetary policy

Southern and eastern Mediterranean countries have many fiscal challenges in common with other emerging market and mature economies concerning deficit and debt reduction and the maintenance of fiscal discipline. However, most countries in the region also face some specific fiscal issues, such as relatively high public debt, dependence on some form or another of donor dependence or concessional financing, high budgetary exposure to fluctuations in hydrocarbon prices, high defence expenditure and weak tax bases. Against this background, this paper reviews fiscal developments and fiscal policy issues in the ten countries that are participants or observers in the EU’s Barcelona process. The main focus is on the implications of these developments and issues for macroeconomic stability, given that countries in the region have made considerable progress in terms of macroeconomic stabilisation over the last two decades, which is reflected in particular in lower inflation rates. The analysis distinguishes between non-oil-producing and oil-producing countries in the region, as they exhibit different fiscal features and are confronted with different challenges. In the case of non-oil-producing countries, the key challenges stem from high deficits and debt levels, including implicit and contingent liabilities, notwithstanding some progress in fiscal consolidation in most of these countries over the last years. In the case of oil-producing countries, whose fiscal situation has significantly improved in recent years in the wake of high oil prices, the key challenges for fiscal management stem from the heavy reliance on an exhaustible source of revenues and a large exposure to fluctuations in international hydrocarbon prices. A shock originating from – or being transmitted via and exacerbated by – the fiscal sector appears to be the single most important macroeconomic risk in many countries.

SWIM: A computational tool to unveiling crucial nodes in complex biological networks

SWItchMiner (SWIM) is a wizard-like software implementation of a procedure, previously described, able to extract information contained in complex networks. Specifically, SWIM allows unearthing the existence of a new class of hubs, called "fight-club hubs", characterized by a marked negative correlation with their first nearest neighbors. Among them, a special subset of genes, called "switch genes", appears to be characterized by an unusual pattern of intra- and inter-module connections that confers them a crucial topological role, interestingly mirrored by the evidence of their clinic-biological relevance. Here, we applied SWIM to a large panel of cancer datasets from The Cancer Genome Atlas, in order to highlight switch genes that could be critically associated with the drastic changes in the physiological state of cells or tissues induced by the cancer development. We discovered that switch genes are found in all cancers we studied and they encompass protein coding genes and non-coding RNAs, recovering many known key cancer players but also many new potential biomarkers not yet characterized in cancer context. Furthermore, SWIM is amenable to detect switch genes in different organisms and cell conditions, with the potential to uncover important players in biologically relevant scenarios, including but not limited to human cancer