UEBERflow

In der Dissertation wird der Frage nachgegangen, welche globalen bildungspolitischen Maßnahmen erforderlich sind, um auch bislang exkludierten Menschen den Kompetenzerwerb zu ermöglichen, der benötigt wird, eine positive User Experience in benutzergenerierten, digitalen Lernumgebungen auszubilden, damit sie an der modernen Weltgesellschaft selbstbestimmt teilhaben können. Zu diesem Zweck wurden Castells ‘Netzwerkgesellschaft’ und Csikszentmihalys ‘Theorie der optimalen Erfahrung’ als analytische Grundlagen zur Einordnung der sozialen Netzwerk-Aktivitäten herangezogen. Dies ermöglichte es, unter Rückgriff auf aktuelle Lerntheorien, Kompetenzdebatten, ökonomische Analysen des Bildungssystems und User Experience-Forschungen, einige individuelle und gesamtgesellschaftliche Voraussetzungen abzuleiten, um in der Netzwerkgesellschaft konstruktiv überleben zu können. Mit Blick auf unterschiedliche sozio-kulturelle Bedingungen für persönlichen Flow im ‘space of flows’ liessen sich schließlich differenzierte Flow-Kriterien entwickeln, die als Grundlage für die Operationalisierung im Rahmen einer Real-Time Delphi (RTD)-Studie mit einem internationalen Expertinnen-Panel dienen konnten. Ziel war es, bildungspolitische Ansatzpunkte zu finden, den bislang Exkludierten bis zum Jahre 2020 erste Rahmenbedingungen zu bieten, damit sie potentiell teilhaben können an der Gestaltung der zukünftigen Netzwerkgesellschaft. Das Ergebnis der Expertinnen-Befragung wurde unter Rückgriff auf aktuelle Global und Educational Governance-Studien und das Einflusspotenzial der Zivilgesellschaft auf den Digital Divide reflektiert. Vor diesem Hintergrund konnten abschließend vier bildungspolitische Verlaufsszenarien entworfen werden, die es ermöglichen könnten, bis 2020 die Kluft zu den global Exkludierten wenigstens etwas zu schließen.

Optimal control theory for a unitary operation under dissipative evolution

We show that optimizing a quantum gate for an open quantum system requires the time evolution of only three states irrespective of the dimension of Hilbert space. This represents a significant reduction in computational resources compared to the complete basis of Liouville space that is commonly believed necessary for this task. The reduction is based on two observations: the target is not a general dynamical map but a unitary operation; and the time evolution of two properly chosen states is sufficient to distinguish any two unitaries. We illustrate gate optimization employing a reduced set of states for a controlled phasegate with trapped atoms as qubit carriers and a iSWAP gate with superconducting qubits.

Integrating top down policies and bottom up practices in Urban and Periurban Agriculture: an Italian dilemma

The paper deals with some relevant and contradictory aspects of urban and peri-urban agriculture in Italy: the traditional exclusion of agricultural areas from the goals of territorial planning; the separation between top-down policies and bottom-up practices; the lack of agricultural policies at local scale. In the first part the paper summarises the weak relation between urban planning and agriculture, showing how in Italy this gap has been only partially overcome by new laws and plans. Moreover the paper focuses on how, due to the lack of suitable solutions coming from regional and local planning, a large number of vibrant initiatives were started by local stakeholders. In order to show the limitations and the potentialities of these various approaches, three peculiar experiences based on Milan, Turin and Pisa are presented. They give a cross-section of the variegated Italian situation, demonstrating that a major challenge in Italian context affects the fields of governance and inclusiveness.

Efficient Characterisation and Optimal Control of Open Quantum Systems - Mathematical Foundations and Physical Applications

Since no physical system can ever be completely isolated from its environment, the study of open quantum systems is pivotal to reliably and accurately control complex quantum systems. In practice, reliability of the control field needs to be confirmed via certification of the target evolution while accuracy requires the derivation of high-fidelity control schemes in the presence of decoherence. In the first part of this thesis an algebraic framework is presented that allows to determine the minimal requirements on the unique characterisation of arbitrary unitary gates in open quantum systems, independent on the particular physical implementation of the employed quantum device. To this end, a set of theorems is devised that can be used to assess whether a given set of input states on a quantum channel is sufficient to judge whether a desired unitary gate is realised. This allows to determine the minimal input for such a task, which proves to be, quite remarkably, independent of system size. These results allow to elucidate the fundamental limits regarding certification and tomography of open quantum systems. The combination of these insights with state-of-the-art Monte Carlo process certification techniques permits a significant improvement of the scaling when certifying arbitrary unitary gates. This improvement is not only restricted to quantum information devices where the basic information carrier is the qubit but it also extends to systems where the fundamental informational entities can be of arbitary dimensionality, the so-called qudits. The second part of this thesis concerns the impact of these findings from the point of view of Optimal Control Theory (OCT). OCT for quantum systems utilises concepts from engineering such as feedback and optimisation to engineer constructive and destructive interferences in order to steer a physical process in a desired direction. It turns out that the aforementioned mathematical findings allow to deduce novel optimisation functionals that significantly reduce not only the required memory for numerical control algorithms but also the total CPU time required to obtain a certain fidelity for the optimised process. The thesis concludes by discussing two problems of fundamental interest in quantum information processing from the point of view of optimal control - the preparation of pure states and the implementation of unitary gates in open quantum systems. For both cases specific physical examples are considered: for the former the vibrational cooling of molecules via optical pumping and for the latter a superconducting phase qudit implementation. In particular, it is illustrated how features of the environment can be exploited to reach the desired targets.

How do domestic policies affect the integration of Ethiopian fertiliser markets with world markets?

Frequent shifts in policy on fertiliser markets have occurred in Ethiopia with the aim of facilitating both physical and economic access of farmers to fertiliser. The last shift was the introduction of a monopoly on each stage of the supply chain in 2008. Furthermore, government control of prices and margins as well as stockholding programmes are also present on the markets. This paper evaluates the effect of these policies on the integration of domestic with world markets of fertiliser, using cointegration methods. Time series data of diammonium phosphate (DAP) and urea prices on world, import and retail markets between 1971 and 2012 are used. The findings show high transmission of price signals from world markets to import prices for both DAP and urea. However, between import and retail prices there is no evidence of cointegration for urea, while for DAP full price transmission is concluded. In the retail market, domestic transaction costs associated with storing large volumes of fertiliser act as a buffer between import and retail prices, especially for urea. Therefore, economic benefits could be achieved by reducing the size of stocks and revising the demand estimation process.

Optimal Unsupervised Learning in Feedforward Neural Networks

We investigate the properties of feedforward neural networks trained with Hebbian learning algorithms. A new unsupervised algorithm is proposed which produces statistically uncorrelated outputs. The algorithm causes the weights of the network to converge to the eigenvectors of the input correlation with largest eigenvalues. The algorithm is closely related to the technique of Self-supervised Backpropagation, as well as other algorithms for unsupervised learning. Applications of the algorithm to texture processing, image coding, and stereo depth edge detection are given. We show that the algorithm can lead to the development of filters qualitatively similar to those found in primate visual cortex.

Sequential Optimal Recovery: A Paradigm for Active Learning

In most classical frameworks for learning from examples, it is assumed that examples are randomly drawn and presented to the learner. In this paper, we consider the possibility of a more active learner who is allowed to choose his/her own examples. Our investigations are carried out in a function approximation setting. In particular, using arguments from optimal recovery (Micchelli and Rivlin, 1976), we develop an adaptive sampling strategy (equivalent to adaptive approximation) for arbitrary approximation schemes. We provide a general formulation of the problem and show how it can be regarded as sequential optimal recovery. We demonstrate the application of this general formulation to two special cases of functions on the real line 1) monotonically increasing functions and 2) functions with bounded derivative. An extensive investigation of the sample complexity of approximating these functions is conducted yielding both theoretical and empirical results on test functions. Our theoretical results (stated insPAC-style), along with the simulations demonstrate the superiority of our active scheme over both passive learning as well as classical optimal recovery. The analysis of active function approximation is conducted in a worst-case setting, in contrast with other Bayesian paradigms obtained from optimal design (Mackay, 1992).

European employment strategy and spanish labour market policies

The paper aim is to analyse the influence of the European Employment Strategy (EES)in the implementation of the Spanish labour market policies. The first part of the paper describes the evolution and content of the EES. In the second one, the definition of activation is also explained. In addition to that, the ways how the EES develops and promotes active labour market policies are examined. The evolution of labour market policies in Spain and the current configuration of both active and passive policies are studied in the next three chapters. In these parts, the paper investigates to which extent the provisions of the EES have been implemented in Spain. The paper shows that: i) activation has been rising in the European countries since the implementation of the EES; ii) this fact has also happened in relative terms (comparing the evolution of active to passive policies); iii) Spain has been one of the countries which has led these processes; iv) the EES seems to have been influencing

Optimal Methodology for Synchronized Scheduling of Parallel Station Assembly with Air Transportation

We present an optimal methodology for synchronized scheduling of production assembly with air transportation to achieve accurate delivery with minimized cost in consumer electronics supply chain (CESC). This problem was motivated by a major PC manufacturer in consumer electronics industry, where it is required to schedule the delivery requirements to meet the customer needs in different parts of South East Asia. The overall problem is decomposed into two sub-problems which consist of an air transportation allocation problem and an assembly scheduling problem. The air transportation allocation problem is formulated as a Linear Programming Problem with earliness tardiness penalties for job orders. For the assembly scheduling problem, it is basically required to sequence the job orders on the assembly stations to minimize their waiting times before they are shipped by flights to their destinations. Hence the second sub-problem is modelled as a scheduling problem with earliness penalties. The earliness penalties are assumed to be independent of the job orders.

Risk Aversion in Inventory Management

Traditional inventory models focus on risk-neutral decision makers, i.e., characterizing replenishment strategies that maximize expected total profit, or equivalently, minimize expected total cost over a planning horizon. In this paper, we propose a framework for incorporating risk aversion in multi-period inventory models as well as multi-period models that coordinate inventory and pricing strategies. In each case, we characterize the optimal policy for various measures of risk that have been commonly used in the finance literature. In particular, we show that the structure of the optimal policy for a decision maker with exponential utility functions is almost identical to the structure of the optimal risk-neutral inventory (and pricing) policies. Computational results demonstrate the importance of this approach not only to risk-averse decision makers, but also to risk-neutral decision makers with limited information on the demand distribution.

Relación entre el impuesto de renta y la generación de empleo en Colombia - Externalidades generadas en las empresas y en los inversionistas

El artículo analiza la relación que ha existido en Colombia a partir de la década de los años 90 s- entre el impuesto de renta y la generación de empleo. En el estudio se identificaron los principales obstáculos que enfrenta la política tributaria colombiana; entre ellos los altos costos laborales salariales y no salariales (impuestos a la nómina), la acción de los grupos de presión, el desempleo, excesos en la formulación de exenciones y descuentos tributarios injustificados al igual que la necesidad de formular políticas tributarias y laborales viables a mediano y largo plazo. Como puede verse a lo largo de la investigación, estos elementos han impedido la consecución de una política tributaria óptima que contemple los principios de equidad, progresividad, eficiencia y flexibilidad.

Optimal Traffic Grooming in WDM using Lighttours

Recent developments in optical communications have allowed simpler optical devices to improve network resource utilization. As such, we propose adding a lambda-monitoring device to a wavelength-routing switch (WRS) allowing better performance when traffic is routed and groomed. This device may allow a WRS to aggregate traffic over optical routes without incurring in optical-electrical-optical conversion for the existing traffic. In other words, optical routes can be taken partially to route demands creating a sort of "lighttours". In this paper, we compare the number of OEO conversions needed to route a complete given traffic matrix using either lighttours or lightpaths