Invariance quantum group of the fermionic oscillator

The fermionic oscillator defined by the algebraic relations cc^*+c^*c=1 and c^{2}=0 admits the homogeneous group O(2) as its invariance group. We show that, the structure of the inhomogeneous invariance group of this oscillator is a quantum group.Comment: 7 A4 page

Modelling the components of binaries in Hyades: The dependence of the mixing-length parameter on stellar mass

We present our findings based on a detailed analysis for the binaries of the Hyades, in which the masses of the components are well known. We fit the models of components of a binary system to the observations so as to give the observed total V and B-V of that system and the observed slope of the main-sequence in the corresponding parts. According to our findings, there is a very definite relationship between the mixing-length parameter and the stellar mass. The fitting formula for this relationship can be given as $alpha = 9.19 (M/M_sun-0.74)^{0.053}-6.65$, which is valid for stellar masses greater than 0.77 M_sun. While no strict information is gathered for the chemical composition of the cluster, as a result of degeneracy in the colour-magnitude diagram, by adopting Z=0.033 and using models for the components of 70 Tau and theta^2 Tau we find the hydrogen abundance to be X=0.676 and the age to be 670 Myr. If we assume that Z=0.024, then X=0.718 and the age is 720 Myr. Our findings concerning the mixing length parameter are valid for both sets of the solution. For both components of the active binary system V818 Tau, the differences between radii of the models with Z=0.024 and the observed radii are only about 4 percent. More generally, the effective temperatures of the models of low mass stars in the binary systems studied are in good agreement with those determined by spectroscopic methods.Comment: 11 pages, 7 figures, accepted for publication in MNRA

A Model-Derivation Framework for Software Analysis

Model-based verification allows to express behavioral correctness conditions like the validity of execution states, boundaries of variables or timing at a high level of abstraction and affirm that they are satisfied by a software system. However, this requires expressive models which are difficult and cumbersome to create and maintain by hand. This paper presents a framework that automatically derives behavioral models from real-sized Java programs. Our framework builds on the EMF/ECore technology and provides a tool that creates an initial model from Java bytecode, as well as a series of transformations that simplify the model and eventually output a timed-automata model that can be processed by a model checker such as UPPAAL. The framework has the following properties: (1) consistency of models with software, (2) extensibility of the model derivation process, (3) scalability and (4) expressiveness of models. We report several case studies to validate how our framework satisfies these properties.Comment: In Proceedings MARS 2017, arXiv:1703.0581

Foreign Direct Investment and Inequality in Productivity across Countries

Using data for 93 countries for a period from 1970 to 2000, this paper examines the effects of foreign direct investment (FDI) on cross-country differences in productivity. We construct a spatial Gini coefficient of labor productivity across countries, and weighted indices of FDI and gross domestic investment (GDI). We then examine their time series properties to explore the relations of FDI and GDI with productivity. Although we find little evidence of FDI flows – which have increased manifold in last three decades – reducing inequality in productivity for the entire sample, our analysis shows that these three variables are cointegrated for developed, high and middle income developing countries, indicating existence of a long-run equilibrium relationships between FDI, GDI and productivity. FDI seems to reduce inequality in productivity among high and middle income developing countries while it widens productivity gaps among developed countries in the long-run though these effects are statistically significant only for high income developing countries. In middle income developing countries, higher GDI seems to have significant effect in reducing productivity differences. Granger causality tests further suggest that FDI causes productivity differences among petroleum exporting countries. Furthermore, GDI granger causes FDI in high income countries and productivity differences Granger cause FDI into the middle income developing countries.

A Model-Derivation Framework for Software Analysis

Model-based verification allows to express behavioral correctness conditions like the validity of execution states, boundaries of variables or timing at a high level of abstraction and affirm that they are satisfied by a software system. However, this requires expressive models which are difficult and cumbersome to create and maintain by hand. This paper presents a framework that automatically derives behavioral models from real-sized Java programs. Our framework builds on the EMF/ECore technology and provides a tool that creates an initial model from Java bytecode, as well as a series of transformations that simplify the model and eventually output a timed-automata model that can be processed by a model checker such as UPPAAL. The framework has the following properties: (1) consistency of models with software, (2) extensibility of the model derivation process, (3) scalability and (4) expressiveness of models. We report several case studies to validate how our framework satisfies these properties.Comment: In Proceedings MARS 2017, arXiv:1703.0581