University of Milan

About: University of Milan is a education organization based out in Milan, Italy. It is known for research contribution in the topics: Population & Medicine. The organization has 58413 authors who have published 139784 publications receiving 4636354 citations. The organization is also known as: Università degli Studi di Milano & Statale.

The Effect of Immigration along the Distribution of Wages

Abstract: This paper analyses the effect immigration has on wages of native workers. Unlike most previous work, we estimate wage effects along the distribution of wages. We derive a flexible empirical strategy that does not rely on pre-allocating immigrants to particular skill groups. In our empirical analysis, we demonstrate that immigrants downgrade considerably upon arrival. As for the effects on native wages, we find that immigration depresses wages below the 20th percentile of the wage distribution, but leads to slight wage increases in the upper part of the wage distribution. The overall wage effect of immigration is slightly positive. The positive wage effects we find are, although modest, too large to be explained by an immigration surplus. We suggest alternative explanations, based on the idea that immigrants are paid less than the value of what they contribute to production, generating therefore a surplus, and we assess the magnitude of these effects.

Effective field theories for heavy quarkonium

Abstract: We briefly review how nonrelativistic effective field theories give us a definition of the QCD potentials and a coherent field-theory-derived quantum-mechanical scheme to calculate the properties of bound states made by two or more heavy quarks. In this framework heavy quarkonium properties depend only on the QCD parameters (quark masses and αs) and nonpotential corrections are systematically accounted for. The relation between the form of the nonperturbative potentials and the low-energy QCD dynamics is also discussed.

A fine-grained access control system for XML documents

Abstract: Web-based applications greatly increase information availability and ease of access, which is optimal for public information. The distribution and sharing of information via the Web that must be accessed in a selective way, such as electronic commerce transactions, require the definition and enforcement of security controls, ensuring that information will be accessible only to authorized entities. Different approaches have been proposed that address the problem of protecting information in a Web system. However, these approaches typically operate at the file-system level, independently of the data that have to be protected from unauthorized accesses. Part of this problem is due to the limitations of HTML, historically used to design Web documents. The extensible markup language (XML), a markup language promoted by the World Wide Web Consortium (W3C), is de facto the standard language for the exchange of information on the Internet and represents an important opportunity to provide fine-grained access control. We present an access control model to protect information distributed on the Web that, by exploiting XML's own capabilities, allows the definition and enforcement of access restrictions directly on the structure and content of the documents. We present a language for the specification of access restrictions, which uses standard notations and concepts, together with a description of a system architecture for access control enforcement based on existing technology. The result is a flexible and powerful security system offering a simple integration with current solutions.