Programmable Logic Controllers ensure the control of many reactive systems. These controllers are most of the time programmed with the languages defined in the IEC 61131– 3 standard. Our goal is the verification of safety properties of programs written in one of these languages: the Ladder Diagram. The main approaches in this field are based on ModelChecking. We propose in this article a Theore...

This paper uses personnel records for workers employed by the Canadian Pacific Railway (CPR) between 1921 and 1944 to examine the extent to which observed career dynamics are consistent with the predictions of various models of internal labor markets. In addition, the findings provide new insight into how internal labor markets responded to Great Depression. Similar to some previous empirical s...

Layoffs, Lemons, Race and Gender This paper expands on Gibbons and Katz (1991) by looking at how the difference in wage losses across plant closing and layoff varies with race and gender. We find that the differences between white males and the other groups are striking and complex. The lemons effect of layoff holds for white males as in Gibbons and Katz model, but not for the other three demog...

We document job characteristics for young, male, urban workers in Mexico, a country with high informal employment and increasing education levels. The sector is composed of two distinct parts: salaried self-employment. On almost every measure, including wages, jobs are lower quality than formal or self-employed ones. characterize short-term type transitions among these show that plays key role ...

This paper examines the effects of a private sector prison work program called the Prison Industry Enhancement Certification Program (PIECP) on unemployment duration, length of formal employment, and earnings of men and women released from various state prisons between 1996 and 2001. The labor market dynamics of formerly incarcerated men and women are also investigated. The program is found to ...

See schedules. There are two example sheets. RECOMMENDED BOOKS: (1) D.S. Lemons, Perfect Form, Princeton University Press. (2) I.M. Gelfand and S.V. Fomin, Calculus of Variations, Dover