Modelling data and voice traffic over IP networks using continuous-time Markov models

Common approaches to IP-traffic modelling have featured the use of stochastic models, based on the Markov property, which can be classified into black box and white box models based on the approach used for modelling traffic. White box models, are simple to understand, transparent and have a physical meaning attributed to each of the associated parameters. To exploit this key advantage, this thesis explores the use of simple classic continuous-time Markov models based on a white box approach, to model, not only the network traffic statistics but also the source behaviour with respect to the network and application. The thesis is divided into two parts: The first part focuses on the use of simple Markov and Semi-Markov traffic models, starting from the simplest two-state model moving upwards to n-state models with Poisson and non-Poisson statistics. The thesis then introduces the convenient to use, mathematically derived, Gaussian Markov models which are used to model the measured network IP traffic statistics. As one of the most significant contributions, the thesis establishes the significance of the second-order density statistics as it reveals that, in contrast to first-order density, they carry much more unique information on traffic sources and behaviour. The thesis then exploits the use of Gaussian Markov models to model these unique features and finally shows how the use of simple classic Markov models coupled with use of second-order density statistics provides an excellent tool for capturing maximum traffic detail, which in itself is the essence of good traffic modelling. The second part of the thesis, studies the ON-OFF characteristics of VoIP traffic with reference to accurate measurements of the ON and OFF periods, made from a large multi-lingual database of over 100 hours worth of VoIP call recordings. The impact of the language, prosodic structure and speech rate of the speaker on the statistics of the ON-OFF periods is analysed and relevant conclusions are presented. Finally, an ON-OFF VoIP source model with log-normal transitions is contributed as an ideal candidate to model VoIP traffic and the results of this model are compared with those of previously published work.

Using Helix-coil Models to Study Protein Unfolded States

An abstract of a thesis devoted to using helix-coil models to study unfolded states.\\

Research on polypeptide unfolded states has received much more attention in the last decade or so than it has in the past. Unfolded states are thought to be implicated in various

misfolding diseases and likely play crucial roles in protein folding equilibria and folding rates. Structural characterization of unfolded states has proven to be

much more difficult than the now well established practice of determining the structures of folded proteins. This is largely because many core assumptions underlying

folded structure determination methods are invalid for unfolded states. This has led to a dearth of knowledge concerning the nature of unfolded state conformational

distributions. While many aspects of unfolded state structure are not well known, there does exist a significant body of work stretching back half a century that

has been focused on structural characterization of marginally stable polypeptide systems. This body of work represents an extensive collection of experimental

data and biophysical models associated with describing helix-coil equilibria in polypeptide systems. Much of the work on unfolded states in the last decade has not been devoted

specifically to the improvement of our understanding of helix-coil equilibria, which arguably is the most well characterized of the various conformational equilibria

that likely contribute to unfolded state conformational distributions. This thesis seeks to provide a deeper investigation of helix-coil equilibria using modern

statistical data analysis and biophysical modeling techniques. The studies contained within seek to provide deeper insights and new perspectives on what we presumably

know very well about protein unfolded states. \\

Chapter 1 gives an overview of recent and historical work on studying protein unfolded states. The study of helix-coil equilibria is placed in the context

of the general field of unfolded state research and the basics of helix-coil models are introduced.\\

Chapter 2 introduces the newest incarnation of a sophisticated helix-coil model. State of the art modern statistical techniques are employed to estimate the energies

of various physical interactions that serve to influence helix-coil equilibria. A new Bayesian model selection approach is utilized to test many long-standing

hypotheses concerning the physical nature of the helix-coil transition. Some assumptions made in previous models are shown to be invalid and the new model

exhibits greatly improved predictive performance relative to its predecessor. \\

Chapter 3 introduces a new statistical model that can be used to interpret amide exchange measurements. As amide exchange can serve as a probe for residue-specific

properties of helix-coil ensembles, the new model provides a novel and robust method to use these types of measurements to characterize helix-coil ensembles experimentally

and test the position-specific predictions of helix-coil models. The statistical model is shown to perform exceedingly better than the most commonly used

method for interpreting amide exchange data. The estimates of the model obtained from amide exchange measurements on an example helical peptide

also show a remarkable consistency with the predictions of the helix-coil model. \\

Chapter 4 involves a study of helix-coil ensembles through the enumeration of helix-coil configurations. Aside from providing new insights into helix-coil ensembles,

this chapter also introduces a new method by which helix-coil models can be extended to calculate new types of observables. Future work on this approach could potentially

allow helix-coil models to move into use domains that were previously inaccessible and reserved for other types of unfolded state models that were introduced in chapter 1.

The Worsening of the employment and work conditions and its relationship to the self-perceived health in European working population. Relevance and effects of the latest socioeconomic crisis

The recent crisis of the capitalistic economic system has altered the working conditions and occupations in the European Union. The recession situation has accelerated trends and has brought transformations that have been observed before. Changes have not looked the same way in all the countries of the Union. The social occupation norms, labour relations models and the type of global welfare provision can help underline some of these inequalities. Poor working conditions can expose workers to situations of great risk. This is one of the basic assumptions of the theoretical models and analytical studies of the approach to the psychosocial work environment. Changes in working conditions of the population seems to be important to explain in the worst health states. To observe these features in the current period of economic recession it has made a comparative study of trend through the possibilities of the European Working Conditions Survey in the 2005 and 2010 editions. It has also set different multivariate logistic regression models to explore potential partnerships with the worst conditions of employment and work. It seems that the economic crisis has intensified changes in working conditions and highlighted the effects of those conditions on the poor health of the working population. This conclusion can’t be extended for all EU countries; some differences were observed in terms of global welfare models.

Economic crisis and national health system

The text analyzes the impact of the economic crisis in some critical aspects of the National Health System: outcomes, health expenditure, remuneration policy and privatization through Private Public Partnership models. Some health outcomes related to social inequalities are worrying. Reducing public health spending has increased the fragility of the health system, reduced wage income of workers in the sector and increased heterogeneity between regions. Finally, the evidence indicates that privatization does not mean more efficiency and better governance. Deep reforms are needed to strengthen the National Health System.

Commodification of health care systems: The Catalan case

Commodification of the public healthcare system has been a growing process in recent decades, especially in universal healthcare systems and in high-income countries like Spain.  There are substantial differences in the healthcare systems of each autonomous region of Spain, among which Catalonia is characterized by having a mixed healthcare system with complex partnerships and interactions between the public and private healthcare sectors.  Using a narrative review approach, this article addresses various aspects of the Catalan healthcare system, characterizing the privatization and commodification of health processes in Catalonia from a historical perspective with particular attention to recent legislative changes and austerity measures.  The article approximates, the eventual effects that commodification and austerity measures will have on the health of the population and on the structure, accessibility, effectiveness, equity and quality of healthcare services.

The elderly care and domestic services sector during the recent economic crisis. The case of Italy, Spain and France.

Over the past ten years in Italy, Spain and France, the demographic pressure and the increasing women’s participation in labour market have fuelled the expansion of the private provision of domestic and care services. In order to ensure the difficult balance between affordability, quality and job creation, each countries’ response has been different. France has developed policies to sustain the demand side introducing instruments such as vouchers and fiscal schemes, since the mid of the 2000s. Massive public funding has contributed to foster a regular market of domestic and care services and France is often presented as a “best practices” of those policies aimed at encouraging a regular private sector. Conversely in Italy and Spain, the development of a private domestic and care market has been mostly uncontrolled and without a coherent institutional design: the osmosis between a large informal market and the regular private care sector has been ensured on the supply side by migrant workers’ regularizations or the introduction of new employment regulations . The analysis presented in this paper aims to describe the response of these different policies to the challenges imposed by the current economic crisis. In dealing with the retrenchment of public expenditure and the reduced households’ purchasing power, Italy, Spain and France are experiencing greater difficulties in ensuring a regular private sector of domestic and care services. In light of that, the paper analyses the recent economic conjuncture presenting some assumptions about the future risk of deeper inequalities rising along with the increase of the process of marketization of domestic and care services in all the countries under analysis.    

Migrant domestic workers, vulnerability and the law: immigration and employment laws in Cyprus and Spain

The intersection of gender, welfare and immigration regimes has been one of the main focus of a rich scholarship on paid domestic work in Europe. This article brings into the discussion the nexus of employment and immigration law regimes to reflect on the role of legal regulation in structuring and reducing the vulnerability of domestic workers. I analyse this nexus by looking at the cases of Cyprus and Spain, two states falling under the cluster of Southern Mediterranean welfare regimes, that share certain characteristics in terms of immigration regimes, but have substantially different employment law regulation models. The first part sketches the debate on the employment law regulation of domestic work. The second part starts by giving an overview of the immigration regimes of Cyprus and Spain in relation to migrant domestic workers and then proceeds to analyse the two countries’ models and substance of employment law regulation in domestic work. The comparison of these two divergent approaches informs the debate on how the legal regulation of domestic work should be best structured. In Spain there have been recent dynamic legislative changes in the employment law regulation of domestic work. The final part of the article traces these changes and reflects on why such processes have not taken place in Cyprus.

Incertidumbre y actitudes pro-redistributivas: mercados de trabajo y modelos de bienestar en Europa

La articulación entre las políticas de empleo y las políticas sociales condicionan la percepción subjetiva de incertidumbre los individuos. El modelo de mercado laboral tiene un peso determinante en la percepción de incertidumbre. El empleo en sí mismo ya no es suficiente garantía de ingresos seguros. El empleo a tiempo parcial y los contratos temporales generan una creciente demanda de políticas de redistribución de los ingresos en los países del Sur y Este de Europa. En los países escandinavos los mismos tipos de contratos laborales generan menos desigualdad porque el empleo público contribuye a generar un “círculo virtuoso” que favorece las políticas de igualdad y la conciliación entre la vida laboral y familiar. A nivel individual las actitudes pro-redistributivas las impulsan las mujeres, aquellas personas con incertidumbre en sus ingresos económicos y con bajo nivel de estudios. Por el contrario, quienes más confían en el éxito individual y el mérito son los jóvenes con estudios universitarios y aquellos que perciben ingresos económicos altos.

Universities and Welfare States Coping with Permanent Financial Austerity: Pressures on (Competing) Public Institutions

A chapter linking universities and welfare states to permanent financial austerity can take a shorter or a longer historical perspective. This chapter looks further back (to the postwar expansion of European welfare states) to better understand future transformations of both public institutions. Their long-term sustainability problems did not start with the financial crisis of 2008 but have been growing since the 1970s (Schäfer and Streeck 2013; Bonoli and Natali 2012; Hay and Wincott 2012). Financial austerity is not a post-crisis phenomenon. As a concept, it was used in welfare state research at least a decade earlier, although it does not seem to have been used in higher education studies until recently. Two quotations bring us to the heart of the matter: welfare states and universities are currently changing under adverse financial conditions caused by an array of interrelating and mutually reinforcing forces and their long-term financial sustainability is at stake across Europe. The welfare state is a “particular trademark of the European social model” (Svallfors 2012: 1), “the jewel in the crown” and a “fundamental part of what Europe stands for” (Giddens 2006: 14), as are tuition-free universities, the cornerstone of intergenerational social mobility in Continental Europe. The past trajectories of major types of welfare states and of universities in Europe tend to go hand in hand: first vastly expanding following the Second World War, and especially in the 1960s and 1970s, and then being in the state of permanent resource-driven and legitimacy-based “crisis” in the last two decades. Welfare states and universities, two critically important public institutions, seem to be under heavy attacks from the public, the media and politicians. Their long-term sustainability is being questioned, and solutions to their (real and perceived) problems are being sought at global, European, and national levels.

State and economy. William Beveridge and Walter Eucken's criticisms and proposals. (A historical comparative perspective)

The central problem that this paper addresses is the development of political economic thought, both in Germany and in Great Britain, related to the construction of societies in which the State had a role in ensuring levels of stability and economic security to its inhabitants, particularly during the late 1940s -- This article proposes a comparative historical perspective of political economic thought of the British economist William Beveridge and his German counterpart Walter Eucken -- The comparison is based on their critiques to the economic system and proposals on the role that the State should play in the economy -- The study of the ideas of both thinkers, their criticisms and proposals on economic and political issues, allows us to understand the set of ideas that influenced the development of the Welfare State of the post war period, both in Britain and Germany

Convergence of gender roles in a globalized world: international comparison of family and gender roles

This paper examines emerging and changing gender roles in different regions of the world. Using data on 12 countries from last three ISSP Special Modules “Family and Changing Gender Roles” (1994, 2002 and 2012), we compare the evolution of gender roles about motherhood and fatherhood and its relation with the extension of women as breadwinners around the world: four Western Europe countries, representatives of different models of Welfare State (Germany, United Kingdom, Norway and Spain) plus United States, three former Soviet nations (Russia, Poland and Czech Republic), two Latin American countries (Chile and Mexico) and two Asian nations (Japan and Taiwan). Data show that family change (measured both in terms of attitudes and social practices) is spreading from Western contexts to other regions of the world, although the pace of this change varies from one country to another, depending on cultural, economic and political factors.

The local dimension of employment-related welfare policy in Germany, England and Sweden

The link between work and welfare is a key pathway of modern welfare state development in Western Europe. National governments face a constant balancing act between the welfare expectations of the labour forces and the labour market liberalisation demands of the business communities. Facilitating the transit from welfare into employment has therefore become an important tool for the British, German and Swedish governments, providing labour as and when needed while keeping welfare expenditure in check. However, the approaches to organising active labour market policies are quite different, notably with regard to the territorial dimension. Although labour markets are quite diverse in all three cases, the role of local authorities, local agencies and local labour market actors from the private and voluntary sector are generally under-developed and apparently under-appreciated, but in different ways and for different reasons. The article compares current employment-related welfare provisions and approaches to develop active labour market policies in the three countries, and concludes that while certain structural and procedural similarities exist, the basic political priorities and actual support and services provided remain very far apart.

South European welfare regime model and the turkish case

The rise of neoliberalism and the experience of several economic crises throughout 1960’s and 70’s have opened the way to question the ability of welfare state to satisfy the basic needs of the societies. Therefore the term “welfare state” left its place to “welfare regime” in which the responsibilities for the well being of the societies are distributed among state, market and families. Following the introduction of this new term, several typologies of welfare regimes are started to be discussed. Esping-Andersen’s (1990) regime typology is considered to be one of the most significant one which covers most of the European countries. On the other hand, it has also led to criticisms for being lack of several aspects. One of them was done by Ferrera (1996), Moreno (2001), Boboli (1997) and Liebfreid (1992), which discusses that the grouping of Mediterranean countries of Europe -Greece, Italy, Spain and Portugal- within the conservative regime type. Those authors affirm that Southern European countries have their peculiar features in terms of structure of welfare provision and they form a fourth type which may be called "Mediterranean/ Southern European Regime". At this point, this doctoral thesis carries the discussion one step further and covers a profound research to answer some fundamental questions. Chiefly, clarifying whether it is possible to talk about a coherent grouping between the Mediterranean countries of Southern Europe in terms of their welfare regimes is our first objective. Then by assuming that it has an affirmative response, it is aimed to reflect the characteristics of this grouping. On the other hand, those group features are not static in time and they are sensible to various economic changes...

An Examination of the merits of a human rights-based approach to higher education teaching and learning, compared with welfare and market-based approaches.

The thesis concludes that a human rights-based approach to higher education will produce better teaching and learning outcomes than welfare state or market-based approaches. It is intended that this research might influence an improvement in policy-making, identify a ‘feasible utopia’ for higher education, and contribute to discussion about the public interest role of higher education.