The TTC 2013 Flowgraphs Case

This case for the Transformation Tool Contest 2013 is about evaluating the scope and usability of transformation languages and tools for a set of four tasks requiring very different capabilities. One task deals with typical model-to-model transformation problem, there's a model-to-text problem, there are two in-place transformation problems, and finally there's a task dealing with validation of models resulting from the transformations. The tasks build upon each other, but the transformation case project also provides all intermediate models, thus making it possible to skip tasks that are not suited for a particular tool, or for parallelizing the work among members of participating teams.Comment: In Proceedings TTC 2013, arXiv:1311.753

Workplace-based vocational training in Central and Eastern Europe: evidence on the school to work transition of Hungarian apprentices

Although apprenticeship training has been praised for its effectiveness in smoothing the school-to-work transition of non-college bound students in Western European dual education systems, there is a lack of evidence from Central Eastern Europe. Using a unique individual-level panel database, which includes an extensive set of controls, the study shows that Hungarian students of the non-college bound vocational training track with workplace-based training, have about 10-15% higher probability of initial employment, compared to similar graduates from the same track, who were trained in school. This effect seems to be stable across industries, and robust to specification checks

“A Question of Relevance”: The Establishment of a Canadian Parachute Capability, 1942–1945

“The great trouble with starting anything new,” argued Brigadier-General William Mitchell, “is to break away from the conservative policy of those who have gone before.” His observation was born from his own experience as a result of the inertia which existed in the interwar years. Not surprisingly, Canada did little during this period to ensure that it was capable of participating in a modern war. The vacuum of peace was insufficient to overcome the vacillation of military and political decision makers. It was only the stunning German victories of 1939–1940, which provided the catalyst for change and a template of what a modern army required. Predictably, Canadian officers serving overseas in the cauldron of Europe, in May 1940, formed distinct impressions of the new techniques of warfare which had been showcased. The use of airborne forces was one such innovation but proposals to establish a Canadian parachute capability were quickly rejected. The senior military command could not visualize a role for these special troops. More important, there existed an explicit institutional hostility towards the concept. Conventional military minds spurned the distinct, special or unique, and paratroops were seen as a distraction to the serious business of building an army. Nonetheless, the persistent efforts of Colonel E.L.M. Burns, greatly assisted by a growing American and British interest in airborne forces, eventually resulted in the organization of a modest Canadian parachute capability. The reason for this abrupt change is shrouded by inconsistencies. The relevance of a distinct Canadian airborne force was never credibly rationalized. The fact that at war’s end it was quickly dismantled provided silent testimony to its perceived utility. This was the reality of the Canadian airborne experience. Despite the actual performance and unrivalled reputation of the nation’s paratroopers, they never gained the full acceptance of the military establishment. This became the legacy of Canada’s airborne soldiers. Their existence ebbed and flowed on the basis of political expediency and powerful personalities. The failure to rationalize a realistic need for airborne forces, and develop a doctrine which would guide their employment, would remain a weakness which would be the root of their eventual destruction. The Canadian indifference to parachute troops in the interwar period is not surprising. With the exception of Russian and later German experimentation, airborne ideas did not figure largely in the thinking of military commanders in Britain or the United States, much less Canada. However, this lethargy, which in England and in the United States was cloaked in a mantle of slow study and experimentation, was shattered by the chaos of events in Europe. British Air Chief Marshal Sir John Slessor recalled that the “bold and brutal” German airborne operations in Norway and the Low Countries, in the Spring of 1940, deeply impressed everyone, notably Prime Minister Winston Churchill. These events became the catalyst for action

Random Fruits on the Zielonka Tree

Stochastic games are a natural model for the synthesis of controllers confronted to adversarial and/or random actions. In particular, $\omega$-regular games of infinite length can represent reactive systems which are not expected to reach a correct state, but rather to handle a continuous stream of events. One critical resource in such applications is the memory used by the controller. In this paper, we study the amount of memory that can be saved through the use of randomisation in strategies, and present matching upper and lower bounds for stochastic Muller games