Analysing a built-in advantage in asymmetric darts contests using causal machine learning

We analyse a sequential contest with two players in darts where one of the contestants enjoys a technical advantage. Using methods from the causal machine learning literature, we analyse the built-in advantage, which is the first-mover having potentially more but never less moves. Our empirical findings suggest that the first-mover has an 8.6% points higher probability to win the match induced by the technical advantage. Contestants with low performance measures and little experience have the highest built-in advantage. With regard to the fairness principle that contestants with equal abilities should have equal winning probabilities, this contest is ex-ante fair in the case of equal built-in advantages for both competitors and a randomized starting right. Nevertheless, the contest design produces unequal probabilities of winning for equally skilled contestants because of asymmetries in the built-in advantage associated with social pressure for contestants competing at home and away

‘Good job!’ The impact of positive and negative feedback on performance

We analyze the causal impact of positive and negative feedback on professional performance. We exploit a unique data source in which quasi-random, naturally occurring variations within subjective ratings serve as positive and negative feedback. The analysis shows that receiving positive feedback has a favorable impact on subsequent performance, while negative feedback does not have an effect. These main results are found in two different environments and for distinct cultural backgrounds, experiences, and gender of the feedback recipients. The findings imply that managers should focus on giving positive motivational feedback

A general framework to quantify the event importance in multi-event contests

We propose a statistical framework for quantifying the importance of single events that do not provide intermediate rewards but offer implicit incentives through the reward structure at the end of a multi-event contest. Applying the framework to primary elections in the US, where earlier elections have greater importance and influence, we show that schedule variations can mitigate the problem of front-loading elections. When applied to European football, we demonstrate the utility and meaningfulness of quantified event importance in relation to the in-match performance of contestants, to improve outcome prediction and to provide an early indication of public interest

Active labour market policies for the long-term unemployed: New evidence from causal machine learning

We investigate the effectiveness of three different job-search and training programmes for German long-term unemployed persons. On the basis of an extensive administrative data set, we evaluated the effects of those programmes on various levels of aggregation using Causal Machine Learning. We found participants to benefit from the investigated programmes with placement services to be most effective. Effects are realised quickly and are long-lasting for any programme. While the effects are rather homogenous for men, we found differential effects for women in various characteristics. Women benefit in particular when local labour market conditions improve. Regarding the allocation mechanism of the unemployed to the different programmes, we found the observed allocation to be as effective as a random allocation. Therefore, we propose data-driven rules for the allocation of the unemployed to the respective labour market programmes that would improve the status-quo

Entwicklung und Implementierung einer Finite-Elemente-Software für mobile Endgeräte

In dem Vortrag wird die Entwicklung einer Finiten-Elemente-App für Android dargelegt, sowie die Vorteile im Postprozessing von einfachen Strukturen bei der Verwendung der Gestensteuerung erörtert

Third generation autologous chondrocyte implantation is a good treatment option for athletic persons

PURPOSE Autologous chondrocyte implantation is an established method for the treatment of joint cartilage damage. However, to date it has not been established that autologous chondrocyte implantation is an appropriate procedure for cartilage defects therapy in athletic persons. The aim of this study is to analyze if third-generation autologous chondrocyte implantation is an appropriate treatment for athletic persons with full cartilage defect of the knee joints. METHODS A total of 84 patients were treated with third-generation autologous chondrocyte implantation (NOVOCART® 3D). The mean follow-up time was 8 years (5–14). Sports activity was measured via UCLA Activity Score and Tegner Activity Scale before the onset of knee pain and postoperatively in an annual clinical evaluation. 41 athletic persons and 43 non-athletic persons (UCLA-Cut-off: 7; Tegner Activity Scale-Cut-off: 4) were analyzed. Patient reported outcomes were captured using IKDC subjective, KOOS, Lysholm score and VAS score on movement. RESULTS Patient reported outcomes (IKDC, VAS at rest, VAS on movement) showed significant improvement (p < 0.001) postoperatively. Athletic persons demonstrated significantly better results than non-athletic persons in the analyzed outcome scores (IKDC: p < 0.01, KOOS: p < 0.01, Lysholm score: p < 0.01). 96.4% of the patients were able to return to sport and over 50% returned or surpassed their preinjury sports level. The remaining patients were downgraded by a median of two points on the UCLA- and 2.5 on the Tegner Activity Scale. A shift from high-impact sports to active events and moderate or mild activities was found. Furthermore, it was shown that preoperative UCLA score and Tegner Activity Scale correlated significantly with the patient reported outcome postoperatively. CONCLUSION Autologous chondrocyte implantation is a suitable treatment option for athletic persons with full-thickness cartilage defects in the knee. The return to sports activity is possible, but includes a shift from high-impact sports to less strenuous activities

Validierung des Kontaktmoduls der Freeware Z88Aurora anhand analytischer Beispiele und kommerzieller FE-Systeme

Die Finite Elemente Analyse (FEA) ist aus heutiger Sicht aus dem Produktentwicklungsprozess nicht mehr wegzudenken. Zur Sicherstellung einer kontinuierlich wachsenden Innovationskraft sind viele kleine und mittelständische Unternehmen auf einen wirtschaftlichen Einsatz der FEA angewiesen, weshalb diese vermehrt auf Freeware Programme (z.B. Z88Aurora) zurückgreifen. Die dabei meist verwendete, linear statische Analyse von Einzelkomponenten gehört deshalb bei heutigen Simulationsaufgaben längst zum Tagesgeschäft. Diese isolierte Betrachtung von einzelnen Bauteilen ist allerdings oftmals aufgrund der fehlenden Interaktion mit benachbarten Komponenten nicht realitätsnah, weshalb komplexe numerische Simulationen von Baugruppen herangezogen werden müssen. Die Abbildung der gegenseitigen Wechselwirkung entspricht dabei einer nichtlinearen Randbedingung, da sich der Zustand zwischen den Kontaktzonen (offen oder geschlossen) während des Rechenlaufes ändern kann. Dieser technisch-physikalische Effekt lässt sich in nahezu jedem technischen System – beispielsweise einer Zahnradpaarung, einem Kettentrieb, usw. – beobachten, weshalb dessen Berücksichtigung für die Ergebnisgüte eine große Rolle spielt. Das hierfür in Z88Aurora implementierte Kontaktmodul erlaubt dem Anwender ebendiese Anbindung des elastischen Umfeldes sowie eine Detailbetrachtung der Verbindungsstelle (Kontaktdruck). Die für den industriellen Einsatz essentielle Validität der Berechnungsergebnisse wird anhand analytisch berechenbarer Geometrien, wie etwa einem Zugstab, nachgewiesen. Zusätzlich werden die Benchmark-Tests von der National Agency for Finite Element Methods and Standards (NAFEMS) sowie der Kontakt Patch-Test nach Bathe herangezogen, um die Leistungsfähigkeit und Stabilität des Z88-Kontaktalgorithmus zu erproben. Hierbei wird unabhängig von der Ausprägung des Kontaktabstands und der Oberflächenvernetzung der Bauteile die korrekte Finite-Elemente-Kontaktanalyse anhand der Homogenität der Kontaktdruckverteilung bewertet. Auf Basis dieser Benchmark-Tests und weiterführender Vergleichsrechnungen mit kommerziellen FE-Systemen zeigt sich, dass die Ergebnisse des Kontaktmoduls von Z88Aurora valide sind und die Software für den produktiven Einsatz in der Industrie geeignet ist