How do particle physicists learn the programming concepts they need?

The ability to read, use and develop code efficiently and successfully is a key ingredient in modern particle physics. We report the experience of a training program, identified as "Advanced Programming Concepts", that introduces software concepts, methods and techniques to work effectively on a daily basis in a HEP experiment or other programming intensive fields. This paper illustrates the principles, motivations and methods that shape the "Advanced Computing Concepts" training program, the knowledge base that it conveys, an analysis of the feedback received so far, and the integration of these concepts in the software development process of the experiments as well as its applicability to a wider audience.Comment: 8 pages, 2 figures, CHEP2015 proceeding

An automated workflow for parallel processing of large multiview SPIM recordings

Multiview light sheet fluorescence microscopy (LSFM) allows to image developing organisms in 3D at unprecedented temporal resolution over long periods of time. The resulting massive amounts of raw image data requires extensive processing interactively via dedicated graphical user interface (GUI) applications. The consecutive processing steps can be easily automated and the individual time points can be processed independently, which lends itself to trivial parallelization on a high performance cluster (HPC). Here we introduce an automated workflow for processing large multiview, multi-channel, multi-illumination time-lapse LSFM data on a single workstation or in parallel on a HPC. The pipeline relies on snakemake to resolve dependencies among consecutive processing steps and can be easily adapted to any cluster environment for processing LSFM data in a fraction of the time required to collect it.Comment: 13 pages with supplement, LATEX; 1 table, 1 figure, 2 supplementary figures, 2 supplementary lists, 2 supplementary tables; corrected error in results table, results unchange

Regularization and finite element error estimates for elliptic distributed optimal control problems with energy regularization and state or control constraints

In this paper we discuss the numerical solution of elliptic distributed optimal control problems with state or control constraints when the control is considered in the energy norm. As in the unconstrained case we can relate the regularization parameter and the finite element mesh size in order to ensure an optimal order of convergence which only depends on the regularity of the given target, also including discontinuous target functions. While in most cases, state or control constraints are discussed for the more common $L^2$ regularization, much less is known in the case of energy regularizations. But in this case, and for both control and state constraints, we can formulate first kind variational inequalities to determine the unknown state, from wich we can compute the control in a post processing step. Related variational inequalities also appear in obstacle problems, and are well established both from a mathematical and a numerical analysis point of view. Numerical results confirm the applicability and accuracy of the proposed approach

"Die Brücke ist geschlagen": die Konfrontation deutscher Kriegsgefangener mit der Demokratie in amerikanischer und britischer Kriegsgefangenschaft

Die zentrale Fragestellung der Untersuchung befaßt sich mit der Rolle, die die Konfrontation deutscher Kriegsgefangener mit dem Typus der westlichen Demokratie in amerikanischer und britischer Gefangenschaft spielte und der daraus resultierenden politischen Neuorientierung. Dabei liegt die These zugrunde, daß durch die Konfrontation deutscher Gefangener mit den politischen Strukturen und Wertvorstellungen des Westens nicht selten ein Wandel eingeleitet wurde, der die durch die deutsche Diktatur geprägten Werte, Grundüberzeugungen, Einstellungen abschwächte und auch auflöste. Dieser Prozeß ist nicht allein als Denazifizierung zu charakterisieren, sondern entfaltete auf längere Sicht eine Wirkung, die die politische Demokratisierung unterstützte. Dargestellt werden die verschiedenen Programme zur 'Re-education', wobei der Autor unveröffentlichte Quellen ausgewertet hat sowie auf Ergebnisse eines empirischen Projektes des Militärarchivs Freiburg aus den siebziger Jahren zurückgriff. (pra)"From 1942 onward, more and more soldiers of the German Wehrmacht became American prisoners of war (POWs). Among the German POWs, conflicts occurred frequently between opponents of the former National Socialist regime and its adherents. The American occupation authorities attempted early on to win over, or at least influence, German POWs in the direction of western democratic principles. Prison camp newspapers, classes, discussion groups, and other forms were the traditional means for this 'reeducation'. Soon a more systematic program of reeducation was initiated, whose effectiveness is examined here. Over the course of time, one can trace changes in the POWs consclousness. Such changes depended on the age and level of education of individual prisoners, but they also depended on the date when a reading was taken. The closer the end of the war appeared, the more willing prisoners were to rethink their position. Frequent surveys tracked these changes of attitude in detail. This contribution analyses one of the more extensive of such surveys. It is possible to say to what degree, and in what ways, the Americans were able to implement their plan to confront German prisoners of war with the principles and values of the constitutional state. It is possible to determine how such reeducation changed the world views of the POWs. Above all, military defeat increased in many German soldiers the conviction that they had to confront this historical turning point on an intellectual level, and that they had to come to terms with their own past. An oppeness toward the principles of democracy was decisive for many in providing the opportunity to free themselves from habits of mind adopted during the period of dictatorship." (author's abstract

Wahlverhalten im Kaiserreich: Perspektiven und Interpretationsmöglichkeiten

Der Autor beschreibt seine Bestandsaufnahme und Problematisierung des Wahlverhaltens im Kaiserreich als Teilauftrag im Rahmen des wahlhistorischen Forschungsprojekts "Perspektiven einer Analyse von Massendaten der historischen Eliten- und Wahlforschung". Datengrundlage der Untersuchung ist vor allem das "Wahlgeschichtliche Arbeitsbuch" von Gerhard A. Ritter und Merith Niehuss, München 1980. Ausgangspunkt der Untersuchung bilden Fragen nach dem Zusammenhang von sozialer Entwicklung und politischer Einstellung der Bevölkerung, von Verfassungssystem und politischem Alltag auf verschiedenen politischen und regionalen Ebenen. Darin eingebettet sind Fragen nach den Wirkungen föderaler Strukturen auf Parteiensystem und Politikentwicklung, also Betrachtungen der regionalspezifischen Ausgangslage deutscher Parteipolitik und der Nationalisierung der Region im Zuge der Fundamentalpolitisierung und Massendemokratisierung zwischen 1870 und 1914. Es wird dargelegt, daß ein Kenntnisgewinn nur dann zu erwarten ist, wenn es zum einen gelingt, die innere, regionale Differenzierung von Entwicklungen präziser zu fassen und zum anderen, die Datengrundlage der herkömmlichen Wahlstatistik zu erweitern, indem die überlieferte Aggregatebene unterschritten wird. Die Untersuchung der Nationalisierung von Regionen geschieht ausgehend von der Ausgangsvermutung, daß es im Zuge von "Nation-Building-Processes" zu einer Verschmelzung unterschiedlicher "traditioneller Milieus" kommt, wobei neue politisch-kulturelle Milieus entstehen. Diese wiederum sind geprägt von den regionalspezifischen Startbedingungen und bleiben abhängig von Entwicklungen und Inszenierungen sowie von Integrationsanstrengungen und -leistungen. (ICF

Nationalisierung, soziale Differenzen und Urbanisierung als Bedingungsfaktoren des Wahlverhaltens im Kaiserreich

In der Regel geht die historische Wahlforschung zum Kaiserreich einzelfall- d.h. wahlkreisbezogen vor. Der vorliegende Beitrag resümiert die Ergebinsse einer Studie, die die ständige Rückbeziehung regionaler Wahlerergebnisse und Wahlkampfbefunde auf die nationale Ebene anstrebt. Indem die Gesamtentwicklung der Parteien im Medium der Wahlergebnisse im Vordergrund steht, wird das Spektrum der jeweiligen Gegenparteien mitberücksichtigt. Der Beitrag versucht insgesamt eine Verbindung von politischer Geschichte und Sozialgeschichte an dem Überschneidungsbereich 'Wahlen' zu verdeutlichen. (pmb)'Research on the field of electoral history has never had a considerable impact on the historiography of the 19th century. Accordingly, the essay pleads for a historical investigation into political movements, making use of the theory of political mobilization as it was developed by Stein Rokkan. Considering the relations between Social Democrats, Catholics, Conservatives, Liberals, and national minority groups as they emerge from election campaigns, polls and election results, it tries to follow some of the main developments of German party history in the 19th century. The survey shows that, towards the end of the 19th century, the Social Democratic Party has virtually exhausted its reservoir of voters. Though the election campaigns aim at mobilizing broader strata of the population, they do not succeed in significantly changing the parliamentary majority in favour of the political left. In spite of social change and new social stratifications the Social Democrats, like all of the major political parties, remain dependent on a fixed clientele of voters. As a result, all of the political parties tend to stabilize their forms of organisation and strategy and thus, even at the close of the 19th century, prefigure the political immobility which was to be one of the characteristic impediments of the Weimar Republic and finally contributed to the failure of the first German democracy.' (author's abstract

Uncertainty Estimation in Instance Segmentation with Star-convex Shapes

Instance segmentation has witnessed promising advancements through deep neural network-based algorithms. However, these models often exhibit incorrect predictions with unwarranted confidence levels. Consequently, evaluating prediction uncertainty becomes critical for informed decision-making. Existing methods primarily focus on quantifying uncertainty in classification or regression tasks, lacking emphasis on instance segmentation. Our research addresses the challenge of estimating spatial certainty associated with the location of instances with star-convex shapes. Two distinct clustering approaches are evaluated which compute spatial and fractional certainty per instance employing samples by the Monte-Carlo Dropout or Deep Ensemble technique. Our study demonstrates that combining spatial and fractional certainty scores yields improved calibrated estimation over individual certainty scores. Notably, our experimental results show that the Deep Ensemble technique alongside our novel radial clustering approach proves to be an effective strategy. Our findings emphasize the significance of evaluating the calibration of estimated certainties for model reliability and decision-making

A global residual‐based stabilization for equal‐order finite element approximations of incompressible flows

Due to simplicity in implementation and data structure, elements with equal-order interpolation of velocity and pressure are very popular in finite-element-based flow simulations. Although such pairs are inf-sup unstable, various stabilization techniques exist to circumvent that and yield accurate approximations. The most popular one is the pressure-stabilized Petrov–Galerkin (PSPG) method, which consists of relaxing the incompressibility constraint with a weighted residual of the momentum equation. Yet, PSPG can perform poorly for low-order elements in diffusion-dominated flows, since first-order polynomial spaces are unable to approximate the second-order derivatives required for evaluating the viscous part of the stabilization term. Alternative techniques normally require additional projections or unconventional data structures. In this context, we present a novel technique that rewrites the second-order viscous term as a first-order boundary term, thereby allowing the complete computation of the residual even for lowest-order elements. Our method has a similar structure to standard residual-based formulations, but the stabilization term is computed globally instead of only in element interiors. This results in a scheme that does not relax incompressibility, thereby leading to improved approximations. The new method is simple to implement and accurate for a wide range of stabilization parameters, which is confirmed by various numerical examples