EU Conditionality on Nationality-Sensitive Matters in Bosnia and Herzegovina: Promoting Democracy or Maintaining the Status Quo? EDAP 5/2013

This paper will analyse the impact of the EU conditionality in Bosnia and Herzegovina (BiH) and its efficacy in promoting democratic changes in this country. It will be argued that as BiH is a unique case, its constitutional constraints must be taken into account because every reform that affects the difficult balance between the three main ethno-religious groups of BiH is perceived as a nationality-sensitive issue and is therefore vulnerable to political pressure. With reference to two specific situations where EU has demanded the BiH political elites to adopt EU-compatible reforms, namely the police reform process and the implementation of the Sejdić and Finci ruling, it will be argued that the use of the conditionality tool has increased inter-ethnic polarization among the political parties, thus preventing Bosnia and Herzegovina from moving forward in the EU integration process

Stability of quaternionic linear systems

The main goal of this paper is to characterize stability and bounded-input-bounded-output (BIBO)-stability of quaternionic dynamical systems. After defining the quaternion skew-field, algebraic properties of quaternionic polynomials such as divisibility and coprimeness are investigated. Having established these results, the Smith and the Smith-McMillan forms of quaternionic matrices are introduced and studied. Finally, all the tools that were developed are used to analyze stability of quaternionic linear systems in a behavioral framework

Dynamical properties of quaternionic behavioral systems

In this paper we study behavioral systems whose trajectories are given as solutions of quaternionic difference equations. As happens in the commutative case, it turns out that quaternionic polynomial matrices play an important role in this context. Therefore we focus our attention on such matrices and derive new results concerning their Smith form. Based on these results, we obtain characterizations of system theoretic properties of quaternionic behaviors

The Compass for Statistical Researchers

We have hiked many miles alongside several professors as we traversed our statistical path -- a regime switching trail which changed direction following a class on the foundations of our discipline. As we play the game of research in that limbo between student and academic, one thing among Prof. Bernardi's teachings has never been more clear: to draw a route in the research map you not only need to know your destination, but you must also understand where you are and how you arrived there

Linear fractional discrete-time systems

Mathematicians have been discussing about the existence (and the meaning) of derivatives and integrals of fractional order since the beginnings of differential calculus. Various concepts of fractional calculus have been developed and some of them were already applied to dynamical systems. In particular, the author already proposed a way to consider systems defined by linear differential equations of fractional order within the so-called behavioral approach. In this paper, it is shown how to generalize, analogously, discrete-time linear systems by defining a certain type of difference equations of fractional order. Some of the ideas and techniques which will be used belong to the theory of dynamical systems on time scales

Shared misunderstandings? Competing and conflicting meaning structures in quality assurance

This article shows how the professional discourse on quality assurance in higher education is building on latent meaning structures that can be competing with each other and even subvert the messages on the manifest level. Taking the case of the Austrian higher education system as an example and employing a reconstructive-interpretative approach rooted in social science hermeneutics, five different meaning patterns are presented: a consumer protection pattern, an educative pattern, an entrepreneurial pattern, a managerial pattern and a quality engineering pattern. By analysing and comparing these patterns, the study argues for paying more attention to latencies and implicit meanings that might be overlooked by focusing on the manifest level of the discourse, in order to not lose track of important contradictions and sources of potential conflict

Analisi di un evento di PTS originato da un incidente di tipo MSLB in un impianto nucleare WWER-1000/320 condotta mediante i codici accoppiati Relap5, Trio_U e Ansys

Titolo della tesi: “Analisi di meccanica della frattura del vessel di un impianto nucleare WWER-1000/320 condotta mediante i codici accoppiati Relap5, Trio_U e Ansys, in caso di un evento di PTS originato da un incidente di tipo MSLB” Riassunto: Il presente lavoro documenta lo studio degli effetti di un PTS (Pressurized Thermal Shock) originato da un MSLB (Main Steam Line Break) sul recipiente in pressione di un reattore di tipo WWER-1000/320. E’ stata condotta una analisi accoppiata fra un codice termoidraulico di sistema (Relap5) e un codice agli elementi finiti (Ansys 5.7) al fine di determinare i margini di sicurezza in relazione all’infragilimento del materiale del vessel. I risultati del calcolo termoidraulico ottenuti da Relap hanno permesso di determinare i carichi termici e meccanici da introdurre nel codice strutturale. Le sollecitazioni determinate con Ansys sono state quindi utilizzate per una analisi di meccanica della frattura condotta su una ipotetica cricca monodimensionale, assiale e circonferenziale, avente 3 differenti valori di profondità: 7 mm (cricca piccola), 73 mm (1/4 dello spessore del vessel), 196 mm (>1/2 dello spessore del vessel); nei calcoli, sia termoidraulici che meccanici, è stata presa in considerazione la presenza del cladding. E’ stato analizzato anche il comportamento di una cricca bidimensionale semiellittica superficiale su vessel senza cladding, avente 3 differenti valori di profondità all’apice: 7 mm, 16 mm e 73 mm con rapporto di aspetto di 0.5, 0.3 e 0.5 rispettivamente. Infine è stata condotta una analisi fluidodinamica tramite codice CFD Trio_U per determinare gli effetti dell’eventuale miscelamento nel downcomer del fluido primario sui risultati di meccanica della frattura. Thesis title: “WWER 1000/320 Reactor Pressure Vessel fracture mechanics analysis in case of PTS originated by a MSLB accident, conducted by coupling Relap5, Trio_U and Ansys codes” Abstract: The present report documents the activity performed to investigate the consequences of a Pressurized Thermal Shock for the Reactor Pressure Vessel of a WWER-1000/320, originated by a Main Steam Line Break accident. The investigation, aimed at the establishing of the embrittlment safety margin for the vessel material, has been conducted estimating the stresses in the pressure structure by the use of Relap5/mod3.3 and Ansys 5.7 coupled codes. The thermal-hydraulic results obtained from the transient analysis conducted by the system code plant nodalisation have been used to determine the mechanical and thermal loads to be employed for the stress computation by the structural finite element model. For conservative reasons, the Fracture Mechanics analysis has been conducted assuming passing through circumferential and axial cracks, adopting three different depth values: 7 mm (shallow crack), 73 mm (1/4 of the thickness) and 196 mm (> 1/2 of the thickness) and a bidimensional semi elliptical surface crack with three different crack tip depth values: 7 mm, 16 mm and 73 mm with aspect ratio of 0.5, 0.3 and 0.5 respectively. The presence of the internal cladding, except for the bidimensional crack, has been taken into account for both thermal-hydraulic and structural calculations; stainless steel and carbon steel physical and mechanical properties have been specified. A fluid-dynamics analysis with CFD Trio_U code has been finally conducted to study the effect of the downcomer fluid mixing on the Fracture Mechanics results

Bayesian model averaging over tree-based dependence structures for multivariate extremes

Describing the complex dependence structure of extreme phenomena is particularly challenging. To tackle this issue we develop a novel statistical algorithm that describes extremal dependence taking advantage of the inherent hierarchical dependence structure of the max-stable nested logistic distribution and that identifies possible clusters of extreme variables using reversible jump Markov chain Monte Carlo techniques. Parsimonious representations are achieved when clusters of extreme variables are found to be completely independent. Moreover, we significantly decrease the computational complexity of full likelihood inference by deriving a recursive formula for the nested logistic model likelihood. The algorithm performance is verified through extensive simulation experiments which also compare different likelihood procedures. The new methodology is used to investigate the dependence relationships between extreme concentration of multiple pollutants in California and how these pollutants are related to extreme weather conditions. Overall, we show that our approach allows for the representation of complex extremal dependence structures and has valid applications in multivariate data analysis, such as air pollution monitoring, where it can guide policymaking