Maser Studies in Evolved Stars

High resolution maps of maser emission provide very detailed information on processes occurring in circumstellar envelopes of late-type stars. A particularly detailed picture of the innermost shells around AGB stars is provided by SiO masers. Considerable progress is being made to provide astrometrically aligned multi-transition simultaneous observations of these masers, which are needed to better constrain the models. In view of the large amount of high quality data available, models should now be developed to fully explain all maser characteristics together (spatial distribution, variability, etc). New generation instruments (VERA, VSOP-2), new observational techniques (frequency-phase transfer), and new models promise important improvements of our knowledge on this topic.Comment: Review talk, to be published in the proceedings of "The 9th European VLBI Network Symposium on The role of VLBI in the Golden Age for Radio Astronomy and EVN Users Meeting", September 23-26, 2008, Bologna, Italy; Proceedings of Science, eds Mantovani et al.; 8 page

Policy making in divided government. A pivotal actors model with party discipline

This article presents a formal model of policy decision-making in an institutional framework of separation of powers in which the main actors are pivotal political parties with voting discipline. The basic model previously developed from pivotal politics theory for the analysis of the United States lawmaking is here modified to account for policy outcomes and institutional performances in other presidential regimes, especially in Latin America. Legislators' party indiscipline at voting and multi-partism appear as favorable conditions to reduce the size of the equilibrium set containing collectively inefficient outcomes, while a two-party system with strong party discipline is most prone to produce 'gridlock', that is, stability of socially inefficient policies. The article provides a framework for analysis which can induce significant revisions of empirical data, especially regarding the effects of situations of (newly defined) unified and divided government, different decision rules, the number of parties and their discipline. These implications should be testable and may inspire future analytical and empirical work.Macroeconomic policy-making, Divided government, Political parties

It's parties that choose electoral systems (or Duverger's Law upside down)

This article presents, discusses and tests the hypothesis that it is the number of parties what can explain the choice of electoral systems, rather than the other way round. Already existing political parties tend to choose electoral systems that, rather than generate new party systems by themselves, will crystallize, consolidate or reinforce previously existing party configurations. A general model develops the argument and presents the concept of 'behavioral-institutional equilibrium' to account for the relation between electoral systems and party systems. The most comprehensive dataset and test of these notions to date, encompassing 219 elections in 87 countries since the 19th century, are presented. The analysis gives strong support to the hypotheses that political party configurations dominated by a few parties tend to establish majority rule electoral systems, while multiparty systems already existed before the introduction of proportional representation. It also offers the new theoretical proposition that strategic party choice of electoral systems leads to a general trend toward proportional representation over time.Elections, electoral systems, political parties, institutional equilibrium

StarGro: Building i* metrics for agile methodologies

Requirements management is one of the cornerstone activities in software development. Agile methodologies use dedicated methods, techniques and artifacts in order to implement this activity. Remarkably, Backlog Grooming is the activity of managing and welcoming changing requirements in SCRUM. However, current industrial practices in agile development still tend to render this process in the shape of a list of statements, features and bug fixes that often leads to a blurred view of the goals of the project, the underestimation of client's needs and the decrease of the ability to respond to changes. In this paper we outline an approach that uses goal and agent oriented modelling techniques in order to fill in this "intentional" gap that current industrial approaches lack.Peer ReviewedPostprint (published version

An agenda-setting model of electoral competition

This paper presents a model of electoral competition focusing on the formation of the public agenda. An incumbent government and a challenger party in opposition compete in elections by choosing the issues that will key out their campaigns. Giving salience to an issue implies proposing an innovative policy proposal, alternative to the status-quo. Parties trade off the issues with high salience in voters’ concerns and those with broad agreement on some alternative policy proposal. Each party expects a higher probability of victory if the issue it chooses becomes salient in the voters’ decision. But remarkably, the issues which are considered the most important ones by a majority of votes may not be given salience during the electoral campaign. An incumbent government may survive in spite of its bad policy performance if there is no sufficiently broad agreement on a policy alternative. We illustrate the analytical potential of the model with the case of the United States presidential election in 2004.Agenda, elections, political competition, issues, salience, agreement.

Functional Verification of Power Electronic Systems

This project is the final work of the degree in Industrial Electronics and Automatic Engineering. It has global concepts of electronics but it focuses in power electronic systems. There is a need for reliable testing systems to ensure the good functionality of power electronic systems. The constant evolution of this products requires the development of new testing techniques. This project aims to develop a new testing system to accomplish the functional verification of a new power electronic system manufactured on a company that is in the power electronic sector . This test system consists on two test bed platforms, one to test the control part of the systems and the other one to test their functionality. A software to perform the test is also designed. Finally, the testing protocol is presented. This design is validated and then implemented on a buck converter and an inverter that are manufactured at the company. The results show that the test system is reliable and is capable of testing the functional verification of the two power electronic system successfully. In summary, this design can be introduced in the power electronic production process to test the two products ensuring their reliability in the market

What other sciences look like

In order to have references for discussing mathematical menus in political science, I review the most common types of mathematical formulae used in physics and chemistry, as well as some mathematical advances in economics. Several issues appear relevant: variables should be well defined and measurable; the relationships between variables may be non-linear; the direction of causality should be clearly identified and not assumed on a priori grounds. On these bases, theoretically-driven equations on political matters can be validated by empirical tests and can predict observable phenomena.Natural and social sciences, econometrics, political science methods, mathematical models, regression analysis

Combination of statistical process control (SPC) methods and classification strategies for situation assessment of batch processes

Postprint (published version

The left-right dimension in Latin America

We present voters' self-placement and 68 political party locations on the left-right dimension in 17 Latin American countries. Innovative calculations are based on data from Latinobarometer annual surveys from 1995 to 2002. Our preliminary analysis of the results suggests that most Latin American voters are relatively highly ideological and rather consistently located on the left-right dimension, but they have very high levels of political alienation regarding the party system. Both voters' self-placement and the corresponding party locations are presently highly polarized between the center and the right, with a significant weakness of leftist or broadly appealing 'populist' positions.Political ideology, left-right dimension, political parties, electoral competition