Incorporating prediction models in the SelfLet framework: a plugin approach

A complex pervasive system is typically composed of many cooperating \emph{nodes}, running on machines with different capabilities, and pervasively distributed across the environment. These systems pose several new challenges such as the need for the nodes to manage autonomously and dynamically in order to adapt to changes detected in the environment. To address the above issue, a number of autonomic frameworks has been proposed. These usually offer either predefined self-management policies or programmatic mechanisms for creating new policies at design time. From a more theoretical perspective, some works propose the adoption of prediction models as a way to anticipate the evolution of the system and to make timely decisions. In this context, our aim is to experiment with the integration of prediction models within a specific autonomic framework in order to assess the feasibility of such integration in a setting where the characteristics of dynamicity, decentralization, and cooperation among nodes are important. We extend an existing infrastructure called \emph{SelfLets} in order to make it ready to host various prediction models that can be dynamically plugged and unplugged in the various component nodes, thus enabling a wide range of predictions to be performed. Also, we show in a simple example how the system works when adopting a specific prediction model from the literature

Financial Intermediation, Competition, and Risk: A General Equilibrium Exposition

We study a simple general equilibrium model in which investment in a risky technology is subject to moral hazard and banks can extract market power rents. We show that more bank competition results in lower economy-wide risk, lower bank capital ratios, more efficient production plans and Pareto-ranked real allocations. Perfect competition supports a second best allocation and optimal levels of bank risk and capitalization. These results are at variance with those obtained by a large literature that has studied a similar environment in partial equilibrium. Importantly, they are empirically relevant, and demonstrate the need of general equilibrium modeling to design financial policies aimed at attaining socially optimal levels of systemic risk in the economy.General Equilibrium;Bank Competition;Market Power Rents;Risk

Relation between Financial Market Structure and the Real Economy: Comparison between Clustering Methods

We quantify the amount of information filtered by different hierarchical clustering methods on correlations between stock returns comparing it with the underlying industrial activity structure. Specifically, we apply, for the first time to financial data, a novel hierarchical clustering approach, the Directed Bubble Hierarchical Tree and we compare it with other methods including the Linkage and k-medoids. In particular, by taking the industrial sector classification of stocks as a benchmark partition, we evaluate how the different methods retrieve this classification. The results show that the Directed Bubble Hierarchical Tree can outperform other methods, being able to retrieve more information with fewer clusters. Moreover, we show that the economic information is hidden at different levels of the hierarchical structures depending on the clustering method. The dynamical analysis on a rolling window also reveals that the different methods show different degrees of sensitivity to events affecting financial markets, like crises. These results can be of interest for all the applications of clustering methods to portfolio optimization and risk hedging.Comment: 31 pages, 17 figure

Capital Regulation, Liquidity Requirements and Taxation in a Dynamic Model of Banking

This paper formulates a dynamic model of a bank exposed to both credit and liquidity risk, which can resolve financial distress in three costly forms: fire sales, bond issuance and equity issuance. We use the model to analyze the impact of capital regulation, liquidity requirements and taxation on banks' optimal policies and metrics of efficiency of intermediation and social value. We obtain three main results. First, mild capital requirements increase bank lending, bank efficiency and social value relative to an unregulated bank, but these benefits turn into costs if capital requirements are too stringent. Second, liquidity requirements reduce bank lending, efficiency and social value significantly, they nullify the benifits of mild capital requirements, and their private and social costs increase monotonically with their stringency. Third, increases in corporate income and bank liabilities taxes reduce bank lending, bank effciency and social value, with tax receipts increasing with the former but decreasing with the latter. Moreover, the effects of an increase in both forms of taxation are dampened if they are jointly implemented with increases in capital and liquidity requirements.Capital requirements;liquidity requirements;taxation of liabilities. JEL Classifications

Multiple Agreement Constructions in Southern Italo-Romance. The Syntax of Sicilian Pseudo-Coordination

In the present thesis different configurations of Pseudo-Coordination are analysed. This is a monoclausal syntactic construction, formed by two finite verbs with an optional connector a between them (V1 a V2), which can be considered as an instance of the Multiple Agreement Constructions found in most southern Italo-Romance dialects. This thesis discusses the main parameters of micro-variation characterising the Pseudo-Coordination found in the Sicilian dialects: i) the criteria for the selection of the V1; ii) the Moods and the Tenses in which this construction can occur; iii) the criteria for the selection of the V2: iv) the hierarchy regulating the occurrence of the Persons (from 1sg to 3pl) in the different paradigms; v) the grammaticalisation of the V1 "go" with its phonetic erosion and desemanticisation. In the second part of the thesis, the first quantitative study dedicated to Pseudo-Coordination, conducted in Delia (Caltanissetta) with 70 participants during 2017, is presented

Strategies of Indefiniteness Marking in Central Sicilian—Evidence from the Dialect of Delia

This paper is meant as a contribution to the research project on variation and optionality in the determiner system in Italo-Romance, with novel data from the Sicilian dialect of Delia. The study is based on fieldwork interviews and the construction of a small corpus of 850 observations by 24 native speakers of Deliano (mean age: 36.37; age range: 19–72). The participants were asked to (i) describe in Deliano a 3 min videotape of an Italian speaking woman during her shopping session at a supermarket and (ii) talk about their own shopping routines in Deliano. These activities were designed mainly to detect the following strategies to express indefiniteness: (i) ART, i.e., a definite article with an indefinite interpretation; (ii) ZERO, a zero determiner for bare nouns; (iii) DI+ART, the so-called “partitive article”; (iv) pseudo-partitives such as ‘a bit of’; (v) the grammaticalised cardinal ‘two’; and (vi) the grammaticalised cardinal ‘four’. The data confirm (i) the preference for ZERO in negative episodic sentences in the past; (ii) the general lack of bare DI and DI+ART, and of certo ‘certain’ used as an indefinite; (iii) the use of different specialised forms of pseudo-partitive ‘a bit of’ in older speakers of Deliano; (iv) the neutralisation of this pseudo-partitive specialisation and the consequent emergence of some true optionality in younger speakers

Competing verbal constructions with functional TAKE in Bulgarian

This paper discusses the preliminary results of an online acceptability judgments questionnaire on some Bulgarian verbal periphrases featuring the functional verb vzemam ‘take’. The study was conceived to fill a gap in the literature about functional TAKE in Bulgarian, which has been known in previous work since Sandfeld (1900) but is still rather scarce and unsystematic. Three TAKE+V2 constructions are identified: i) a Multiple Agreement Construction featuring the connector da (TAKE daMAC); ii) a MAC featuring ˇce (TAKE ˇceMAC); iii) Pseudo-Coordination (of the type TAKE + i ‘and’ + V2). The participants are 157 native speakers (112 F, 45 M) with an age range of 18-80 (M = 43.63; SD = 13.92). The results of the questionnaire confirm the presence and the productivity of these constructions with functional TAKE in present-day Bulgarian. Moreover, they show that these constructions all share a monoclausal structure, but with some structural differences: V1 in the TAKE MACs is mainly restricted to the past tense, and V2 only occurs in the present, while in the iPseCo V1 and V2 share TAM features and can appear both in the present and in the past. From a semantic point of view, TAKE daMAC specializes for inchoativity, while TAKE ˇceMAC for mirativity. The iPseCo seems to be able to convey both meanings, but it is least preferred than the TAKE MACs

DEPAS: A Decentralized Probabilistic Algorithm for Auto-Scaling

The dynamic provisioning of virtualized resources offered by cloud computing infrastructures allows applications deployed in a cloud environment to automatically increase and decrease the amount of used resources. This capability is called auto-scaling and its main purpose is to automatically adjust the scale of the system that is running the application to satisfy the varying workload with minimum resource utilization. The need for auto-scaling is particularly important during workload peaks, in which applications may need to scale up to extremely large-scale systems. Both the research community and the main cloud providers have already developed auto-scaling solutions. However, most research solutions are centralized and not suitable for managing large-scale systems, moreover cloud providers' solutions are bound to the limitations of a specific provider in terms of resource prices, availability, reliability, and connectivity. In this paper we propose DEPAS, a decentralized probabilistic auto-scaling algorithm integrated into a P2P architecture that is cloud provider independent, thus allowing the auto-scaling of services over multiple cloud infrastructures at the same time. Our simulations, which are based on real service traces, show that our approach is capable of: (i) keeping the overall utilization of all the instantiated cloud resources in a target range, (ii) maintaining service response times close to the ones obtained using optimal centralized auto-scaling approaches.Comment: Submitted to Springer Computin

Diritti sociali e liberta economiche nella prospettiva del diritto privato europeo

Diritti fondamentali e libertà economiche;Il ruolo della Corte di giustizia; La Corte di giustizia e la Corte europea dei diritti dell'uomo tra diritti e libertà;La responsabilità civile dello stat