Heritage and Firm Survival - An Analysis of German Automobile Spinoffs 1886-1939

The theory predicts that spinoffs of successful parents are more successful than others. The success of the parents can be measured in two ways, either in terms of their survival duration or concerning their innovative activity. In this paper, the survival chances of spinoffs in the German automobile industry regarding the success of their parents will be investigated. Therefore it is differentiated between spinoffs of old parents and spinoffs of innovative parents. The results of the Cox regressions show that spinoffs of old parents have better survival chances than those of innovative parents.firm survival

Feature-Aware Verification

A software product line is a set of software products that are distinguished in terms of features (i.e., end-user--visible units of behavior). Feature interactions ---situations in which the combination of features leads to emergent and possibly critical behavior--- are a major source of failures in software product lines. We explore how feature-aware verification can improve the automatic detection of feature interactions in software product lines. Feature-aware verification uses product-line verification techniques and supports the specification of feature properties along with the features in separate and composable units. It integrates the technique of variability encoding to verify a product line without generating and checking a possibly exponential number of feature combinations. We developed the tool suite SPLverifier for feature-aware verification, which is based on standard model-checking technology. We applied it to an e-mail system that incorporates domain knowledge of AT&T. We found that feature interactions can be detected automatically based on specifications that have only feature-local knowledge, and that variability encoding significantly improves the verification performance when proving the absence of interactions.Comment: 12 pages, 9 figures, 1 tabl

Macroeconomic Development and the Life Cycle of the German Automobile Industry, 1886 - 1939

Empirical work studying the industry life cycle highlights the role of knowledge in various forms on the durations firms survive in the industry. This research leaves open the influence of historical events, which are reflected in macroeconomic factors like income, inflation, exports and interest rates on the industry life cycle. In this paper we investigate the relationship between the macroeconomic conditions and firm survival in the German automobile industry during the period 1886-1939. The results reveal that the macroeconomic conditions influence firm survival in addition to the knowledge variables traditionally considered and substantially contribute to explanatory power

Die quantitative Steuerung des Arbeitsangebots als Instrument der Arbeitsmarkt- und Beschäftigungspolitik : die Bundesrepublik Deutschland, Österreich und die Schweiz im internationalen Vergleich

"Der Artikel beschäftigt sich mit der Frage, wie es die Schweiz, Österreich und die Bundesrepublik während der ökonomischen Krisenperiode von 1973 bis 1983 schafften, trotz ihrer Orientierung auf Preisstabilität die Arbeitslosenquote niedrig bzw. - wie im Falle der Bundesrepublik - relativ niedrig zu halten. Ausgehend von der Beobachtung, daß die Nachfrageseite des Arbeitsmarktes keinen Ansatzpunkt für eine Erklärung des arbeitsmakrtpolitischen Erfolges der deutschsprachigen Länder bietet, wird die Entwicklung des Arbeitsangebotes auf ihre Erklärungskraft hin untersucht. Anhand von vergleichenden Analysen der Entwicklung der Erwerbsbeteiligung der Bevölkerung in der OECD wird gezeigt, (1) daß die Bundesrepublik, die Schweiz und Österreich in den siebziger und frühen achtziger Jahren einen im internationalen Vergleich auffälligen Rückgang des Arbeitsangebotes erlebten; (2) daß dieser Rückgang des Arbeitsangebots von den Bevölkerungsgruppen getragen wurde, die eine 'gesellschaftlich anerkannte Alternative zur Beteiligung am Erwerbsleben besitzen'. d.h. von den Jugendlichen, den älteren Arbeitnehmern, den Frauen und den Ausländern; (3) daß der verstärkte Rückzug der 'Alternativrollenbesitzer' aus dem Arbeitsmarkt bzw. ihre auffällige Enthaltsamkeit bezüglich der Beteiligung am Erwerbsleben in nicht unerheblichem Maße das Ergebnis politischer Steuerungen war; und (4) daß er den Arbeitsmarkt deutlich entlastet hat. Ohne den Rückgang des Arbeitsangebots, so wird am Ende geschätzt, wäre die Arbeitslosenquote in der Schweiz, in Österreich und in der Bundesrepublik in den siebziger und frühen achtziger Jahren um vier bis fünf Prozentpunkte höher gewesen." (Autorenreferat)Arbeitsmarktpolitik - internationaler Vergleich, Arbeitskräfteangebot - Entwicklung, Erwerbsbeteiligung, Jugendliche, ältere Arbeitnehmer, Ausländerbeschäftigung, Frauenerwerbstätigkeit, Bundesrepublik Deutschland, Schweiz, Österreich, OECD

Neurodevelopmental and functional outcome in hypoplastic left heart syndrome after Hybrid procedure as stage I

Background: Patients with hypoplastic left heart syndrome (HLHS) undergoing staged palliation until Fontan procedure are at risk for impaired neurodevelopmental (ND) outcome. The Hybrid procedure with bilateral pulmonary artery banding, ductal stenting, and balloon atrioseptostomy may offer a less invasive stage I procedure compared to the Norwood stage I procedure avoiding early neonatal cardiopulmonary bypass (CPB) surgery. Despite altered fetal cerebral hemodynamics, the type of stage I procedure may be a covariate influencing ND outcome and functional outcome may also be altered due to postponing neonatal CPB surgery. Within this review, we analyzed ND outcome as well as functional outcome after Hybrid procedure as stage I procedure. Methods: The review analyzed original publications (OPs) published before March 15, 2022, identified by Cochrane, EMBASE, OVID, Scopus, and Web of science. An OP was included if short-to-long-term neurodevelopment outcome, brain development, somatic, and cardiac outcome in patients for HLHS and variants treated by Hybrid procedure were analyzed. In addition to database searches, we reviewed all references of the analyzed OP to obtain a comprehensive list of available studies. The author, year of publication, demographic characteristics of study population, study design (prospective or retrospective), study assessment, and main findings were summarized. Results: Twenty-one OPs were included with data of patients with ND outcome and functional cardiac outcome. Overall, there is an impaired mid-term ND outcome in patients with Hybrid procedure as stage I for HLHS. Only slight differences between stage I procedures (Hybrid vs. Norwood) in two comparing studies have been determined affecting right ventricular remodeling, short- and mid-term ND outcome, reduced brain growth until two years of age, sufficient quality of life, and altered hemodynamics influencing brain volumes and cerebral perfusion pattern. Conclusions: Despite some minor differences regarding the mid-term follow-up in patients with HLHS comparing Hybrid vs. Norwood procedure, its impact on ND outcome seems rather low. This may be explained by the large number of covariates as well as the small study populations and the different selection criteria for patients undergoing Hybrid or Norwood procedure as stage I

Is Your Error My Concern? An Event-Related Potential Study on Own and Observed Error Detection in Cooperation and Competition

Electroencephalogram studies have identified an error-related event-related potential (ERP) component known as the error-related negativity or ERN, thought to result from the detection of a loss of reward during performance monitoring. However, as own errors are always associated with a loss of reward, disentangling whether the ERN is error- or reward-dependent has proven to be a difficult endeavor. Recently, an ERN has also been demonstrated following the observation of other’s errors. Importantly, other people’s errors can be associated with loss or gain depending on the cooperative or competitive context in which they are made. The aim of the current ERP study was to disentangle the error- or reward-dependency of performance monitoring. Twelve pairs (N = 24) of participants performed and observed a speeded-choice-reaction task in two contexts. Own errors were always associated with a loss of reward. Observed errors in the cooperative context also yielded a loss of reward, but observed errors in the competitive context resulted in a gain. The results showed that the ERN was present following all types of errors independent of who made the error and the outcome of the action. Consequently, the current study demonstrates that performance monitoring as reflected by the ERN is error-specific and not directly dependent on reward

Theoretische und experimentelle Beschreibung von Oberflächenzuständen und negativer Brechung in dielektrischen photonischen Kristallen

von Andreas von RheinPaderborn, Univ., Diss., 200

Analysis Strategies for Configurable Systems

A configurable system enables users to derive individual system variants based on a selection of configuration options. To cope with the often huge number of possible configurations, several analysis approaches (e.g., for verification of configurable systems) implement different strategies to account for configurability. One popular strategy—often applied in practice—is to use sampling (i.e.,analyzing only a subset of all system variants). While sampling reduces the analysis effort significantly, the information obtained is necessarily incomplete as some variants are not analyzed. A second strategy is to identify the common parts and the variable parts of a configurable system and analyze each part separately (called feature-based strategy). As a third strategy, researchers have begun to develop family-based analyses. Family-based approaches analyze the code base of a configurable system as a whole, rather than the individual variants or parts of the system, this way exploiting similarities among individual variants to reduce analysis effort. Each of these three strategies has advantages and disadvantages, which might even prevent its application (e.g., the family-based strategy typically needs much main memory). The goal of this thesis is to enable the efficient analysis of configuable systems, even if existing strategies fail (e.g., the family-based strategy, because of memory limitations). To this end, we designed a framework that models the key aspects of configurable-system analysis strategies, independent of their implementation and of the analyses techniques (e.g., type checking or model checking). Guided by our model, we developed a number of analysis strategies for configurable systems. To learn about advantages and disadvantages of individual strategies, we compared these in a series of empirical studies. In particular, we developed and evaluated a model-checking analysis and a data-flow analysis for configurable systems. One of our key findings is that family-based analysis outperforms most sampling heuristics with respect to analysis time, while being able to make definite statements about all variants of a configurable system. Furthermore, we identified advantages and disadvantages of analysis strategies and how to mitigate them by combining strategies. In our endeavor, we identified two key problems that are common to configurable-system analyses, and we developed supporting techniques to solve them. These techniques are general and are applicable beyond our research. In particular, we developed presence-condition simplification and variability encoding. Presence-condition simplification provides a simple method to reduce the size of the output or the internal data structure of configurable-systemanalyses. Variability encoding provides a means for transforming compile-time variability to run-time variability, which enables many family-based analyses. Our key contributions are the model of analysis strategies for configurable systems and the corresponding empirical comparisons of strategies. Our findings are backed by empirical studies, which helped broaden the community knowledge on analyses of configurable systems (indicated by citations). For these evaluations, we prepared several subject systems, which have also been used already by other researchers. Furthermore, we developed several analysis tools and demonstrated their feasibility in practical application scenarios based on code from, for example, the Linux kernel. Our tools are based on variability-aware optimizations that enable levels of scalability on configurable systems that were not possible with other tools before