SCCharts: The Railway Project Report

SCCharts is a visual language proposed in 2012 for specifying safety-critical reactive systems. We present the results of the first medium sized SCCharts case-study. The case-study was conducted in the context of the railway project performed by students at the Kiel University in the summer term 2014. The railway project is a regularly occurring student training project that teaches principles of concurrent cyber-physical systems on a complex live model railway demonstrator. This report presents details of the first medium size SCCharts models created during the project. We explain what additional language extensions to SCCharts were necessary and how they were implemented. To handle performance issues that arose while developing the controller, compiler enhancements became necessary and are evaluated here. Furthermore, the participants completed a survey at the end of the project to confirm the goals that the SCCharts language and our SCCharts tool chain are suitable to build complex controllers. In the survey, the participants compared both, the SCCharts language and our SCCharts tools, with other modeling and classical programming languages and tools

COMPARATIVE STRESS ANALYSIS OF ELBOWS IN PIPING SYSTEMS APPLYING THE NORMATIVE SAFETY MARGIN

Elbows are components in piping systems whose primary function is to achieve a change in flow direction. Their study is relevant, since they present higher stress levels than those observed in straight sections. Early investigations determined that this effect is caused by the ovalization effect and the presence of external moments. The capacity of a cross section to ovalize when external loads are applied results in increased flexibility of the elbows by decreasing the moment of inertia compared to a straight pipe. In this work, stress levels in elbows caused by external moments and internal pressure are studied. As a case study, a series of elbows of various diameters and thicknesses with suitable characteristics for understanding the phenomenon of ovalization and the comparison of different calculation methodologies is proposed. The stresses obtained by applying the ASME B31.1 and ASME B31.3 codes are compared with those obtained by a numerical model of finite elements, through a novel indicator called the Normative Safety Margin. This indicator considers the admissible stresses established by the specifications for the materials of the accessories. Applying B31.1 Code, higher normative safety margins are obtained than those obtained with B31.3. For the entire series under study and all types of applied loads, lower normative safety margins were obtained when the accessories are more flexible

Making up meanings in a capital city: power, memory and monuments in Berlin

Much contemporary writing on cities focuses on their position within wider global networks, so there is a risk of underplaying the significance of other aspects of the urban experience.This paper explores the particular role of Berlin as capital city in the making of the (new) Berliner Republic and the ways in which it is defined (and defines itself) within that Republic. Berlin is the (and often literally the building) site on which a new Germany is being constructed. The making up of the new Berlin is dominated by attempts to reinterpret and reimagine its history: it is a city of memorials and of deliberate absences; of remembering and forgetting, or trying to forget; of reshaping the past as well as trying to build a new future. The juxtapositions of urban experience, the layering of memories and the attempt to imagine a different future come together to define Berlin as a contemporary capital city

Letters from the people For School board secretary To the editor of the Sentinel I notice that there is a friendly contest on for the appointment of a secretary of the school board in place of Henry E. Legler, who is soon to retire and engage in

On verso, copy 1 and 2: Gift Duane Mowry June 1, 1932; on verso, copy 1: 09-83-467.3; on verso, copy 2: 09-13-467.4