A formal support to business and architectural design for service-oriented systems

Architectural Design Rewriting (ADR) is an approach for the design of software architectures developed within Sensoria by reconciling graph transformation and process calculi techniques. The key feature that makes ADR a suitable and expressive framework is the algebraic handling of structured graphs, which improves the support for specification, analysis and verification of service-oriented architectures and applications. We show how ADR is used as a formal ground for high-level modelling languages and approaches developed within Sensoria

Herds and Coherds

The first aim of this thesis is to give a unified and self-contained treatment of a number of known results related to the theory of herds. This gives us the technical tools to deal with the second aim of our work which is to obtain some new results about herds and coherds in the pure categorical setting. A herd at this level is a pretorsor τ : Q → QPQ satisfying associativity and unitality properties with respect to a formal dual structure M = (A, B, P,Q, σᴬ, σᴮ) ...

Peace at the Lily. The De Franceschi section in the stockbook of Bernardino Giunti

This contribution investigates the catalogue of publications by Francesco De Franceschi, printer, publisher and bookseller between 1561 and 1599, and his heirs, who took over his business until 1624, as recorded in the stockbook of Bernardino Giunti (Los Angeles, University of California Library, Department of Special Collections, call number 170/622), also a printer, publisher and bookseller in Venice at the beginning of the seventeenth century. Each entry of this De Franceschi section has been matched with the edition it was meant to describe, in order to analyse the price of each book according to the Giunti stockbook as the result of material features and book marketing strategies

Demographic forecasts, migration and transition theory: a labor market perspective

The paper proposes a new logical system to build demographic scenarios based on a model that explain migration infl ows as a function of the manpower needs that countries with below replacement fertility are experiencing, as a result both of the decline in Working Age Population and employment growth. Using this approach we show that the WAP of countries characterized by low fertility will necessarily increase; that the migration balance of numerous countries will turn from negative to positive well before 2050; that the level of the international migration fl ows will progressively increase to unprecedented values so that at least 250-300 million people will move from developing countries to developed countries in the next 50 years; that the decline in fertility and the relative rates of employment growth of developed and developing countries will determine radical changes in the pattern of international migrations. The last part of the paper discusses some policy implications of this vision of the future.microsimulation; inequality; in-kind benefits; higher education; university; tuition fees; subsidy

Algebraic Models for Contextual Nets

We extend the algebraic approach of Meseguer and Montanari from ordinary place/transition Petri nets to contextual nets, covering both the collective and the individual token philosophy uniformly along the two interpretations of net behaviors

Effective Classification using a small Training Set based on Discretization and Statistical Analysis

This work deals with the problem of producing a fast and accurate data classification, learning it from a possibly small set of records that are already classified. The proposed approach is based on the framework of the so-called Logical Analysis of Data (LAD), but enriched with information obtained from statistical considerations on the data. A number of discrete optimization problems are solved in the different steps of the procedure, but their computational demand can be controlled. The accuracy of the proposed approach is compared to that of the standard LAD algorithm, of Support Vector Machines and of Label Propagation algorithm on publicly available datasets of the UCI repository. Encouraging results are obtained and discusse

China’s New Demographic Challenge: From Unlimited Supply of Labour to Structural Lack of Labour Supply. Labour market and demographic scenarios: 2008-2048

The paper focuses on the demographic and labour market consequences of the dramatic decline in fertility that has characterized China starting at the beginning of the ‘50s. It is shared opinion that a sustained decline in fertility below replacement level will provoke a decline in Total population, an even more pronounced decline in Working age population and very relevant ageing phenomena. I have recently shown that, on the contrary and coherently with empirical evidence, a decline in fertility provokes a structural lack of labour supply that determines positive migration balances and, finally, positive demographic trends. The paper applies the same approach to China with similar results. The decline in fertility, determined by the process of economic development and its impact on education and urbanization, but promoted also trough the one-child policy, will provoke a relevant and growing structural lack of labour supply, even in the hypothesis that Chinese employment growth should sharply decline. The implication is that in order to continue its road to economic growth and social development, China will have to rely on large and growing migration flows that will determine a demographic expansion. In conclusion, the decline in fertility, actively pursued to set a ceiling to population growth, will end up provoking the opposite result. The uncertainty about the age structure of the Chinese population makes it impossible to determine in which year China will start to be affected by serious labour shortages. Our scenarios do however clearly show that China will reach the Lewis turning point in the next few years and before the middle of the century will become the world largest importer of labour. Our analysis does therefore clearly suggest that any legal restriction to fertility and territorial mobility is totally unwarranted, and that China should start to consider educational and labour policies aimed to mitigate labour shortages. It also indicates the necessity to start an in depth discussion of which immigration and social integration policies could better serve the interests of China, on the light both of the experiences of other countries, and of the role that China wants to play in the international arena.Demography; Labour market; Demographic and labour market scenarios; Migrations; Lewis turning point; China

Gauge dependence in the theory of non-linear spacetime perturbations

Diffeomorphism freedom induces a gauge dependence in the theory of spacetime perturbations. We derive a compact formula for gauge transformations of perturbations of arbitrary order. To this end, we develop the theory of Taylor expansions for one-parameter families (not necessarily groups) of diffeomorphisms. First, we introduce the notion of knight diffeomorphism, that generalises the usual concept of flow, and prove a Taylor's formula for the action of a knight on a general tensor field. Then, we show that any one-parameter family of diffeomorphisms can be approximated by a family of suitable knights. Since in perturbation theory the gauge freedom is given by a one-parameter family of diffeomorphisms, the expansion of knights is used to derive our transformation formula. The problem of gauge dependence is a purely kinematical one, therefore our treatment is valid not only in general relativity, but in any spacetime theory.Comment: paper accepted for publication in Communications of Mathematical Physics; SISSA preprint 105/97/A. 10 pages and 2 figures, standard late

Quasi-isotropic cycles and non-singular bounces in a Mixmaster cosmology

A Bianchi IX Mixmaster spacetime is the most general spatially homogeneous solution of Einstein's equations and it can represent the space-averaged Universe. We introduce two novel mechanisms resulting in a Mixmaster Universe with non-singular bounces which are quasi-isotropic. A fluid with a non-linear equation of state allows non-singular bounces. Using negative anisotropic stresses successfully isotropises this Universe and mitigates the well known Mixmaster chaotic behaviour. Thus the Universe can be an eternal Mixmaster, going through an infinite series of different cycles separated by bounces, with a sizable fraction of cycles isotropic enough to be well approximated by a standard Friedmann-Lema\^itre-Robertson-Walker model from the radiation era onward.Comment: 5 pages, 4 figure