Brian A. Curran; Anthony Grafton; Pamela O. Long; Benjamin Weiss. Obelisk: A History

No abstract

Michael S. Mahoney, 1939–2008

Perhaps the clearest testimony to the scholarly range and depth of Princeton's now‐lamented Michael S. Mahoney lies in the dismay of his colleagues in the last few years, as they contemplated his imminent retirement. How to maintain coverage of his fields? Fretting over this question, the program in history of science that he did so much to build recently found itself sketching a five-year plan that involved replacing him with no fewer than four new appointments: a historian of mathematics with the ability to handle the course on Greek antiquity, a historian of the core problems of the Scientific Revolution, a historian of technology who could cover the nineteenth‐century United States and Britain, and, finally, a historian of the computer-and-media revolution. In his passing we have lost a small department

A study of hierarchical and flat classification of proteins

Automatic classification of proteins using machine learning is an important problem that has received significant attention in the literature. One feature of this problem is that expert-defined hierarchies of protein classes exist and can potentially be exploited to improve classification performance. In this article we investigate empirically whether this is the case for two such hierarchies. We compare multi-class classification techniques that exploit the information in those class hierarchies and those that do not, using logistic regression, decision trees, bagged decision trees, and support vector machines as the underlying base learners. In particular, we compare hierarchical and flat variants of ensembles of nested dichotomies. The latter have been shown to deliver strong classification performance in multi-class settings. We present experimental results for synthetic, fold recognition, enzyme classification, and remote homology detection data. Our results show that exploiting the class hierarchy improves performance on the synthetic data, but not in the case of the protein classification problems. Based on this we recommend that strong flat multi-class methods be used as a baseline to establish the benefit of exploiting class hierarchies in this area

Outside board memberships of CEOs: Expertise or entrenchment?

We investigate whether outside board memberships of CEOs signal expertise or entrenchment. The analysis is based on panel data of the largest German companies covering the period from 1996 to 2008. Supporting the entrenchment hypothesis, our analysis reveals that firms having a CEO with one or more outside mandates suffer from significantly weaker firm performance compared with firms having a CEO without any outside board mandates. Moreover, disciplinary CEO turnovers become less likely and turnover-performance sensitivity declines with rising board memberships of the top manager. We conclude that outside mandates enhance managerial power at the expense of the home firm's shareholders. --Corporate Governance,Entrenchment,Outside Board Memberships,CEO turnover

Solving the TTC 2011 Reengineering Case with GrGen.NET

The challenge of the Reengineering Case is to extract a state machine model out of the abstract syntax graph of a Java program. The extracted state machine offers a reduced view on the full program graph and thus helps to understand the program regarding the question of interest. We tackle this task employing the general purpose graph rewrite system GrGen.NET (www.grgen.net).Comment: In Proceedings TTC 2011, arXiv:1111.440

Competition, outside directors and executive turnover: Implications for corporate governance in the EU

This study contributes to the ongoing debate on the relevance of non-executive outside directors for corporate governance building on a large panel of European listed firms in the period 2003 to 2011. Focusing on executive turnover as an indicator for effective monitoring, the findings reveal that outside directors and product market competition are substitutes. Outsiders increase the performance-turnover sensitivity of executives exclusively if competition in the industry is relatively weak. In an environment with effective competition, outsiders do not significantly influence the decision to replace underperforming managers. In fiercely competitive markets, the higher threat of bankruptcy or hostile takeover seems to effectively limit managerial discretion for opportunistic behavior

Optimal Shuffle Code with Permutation Instructions

During compilation of a program, register allocation is the task of mapping program variables to machine registers. During register allocation, the compiler may introduce shuffle code, consisting of copy and swap operations, that transfers data between the registers. Three common sources of shuffle code are conflicting register mappings at joins in the control flow of the program, e.g, due to if-statements or loops; the calling convention for procedures, which often dictates that input arguments or results must be placed in certain registers; and machine instructions that only allow a subset of registers to occur as operands. Recently, Mohr et al. proposed to speed up shuffle code with special hardware instructions that arbitrarily permute the contents of up to five registers and gave a heuristic for computing such shuffle codes. In this paper, we give an efficient algorithm for generating optimal shuffle code in the setting of Mohr et al. An interesting special case occurs when no register has to be transferred to more than one destination, i.e., it suffices to permute the contents of the registers. This case is equivalent to factoring a permutation into a minimal product of permutations, each of which permutes up to five elements.Comment: 20 pages, 5 figures, full version of a paper accepted at WADS'15. Minor update: fixed typos, corrected comma placemen

Welche Unternehmen berufen Vorstandsvorsitzende und andere Vorstände als externe Kontrolleure? Eine empirische Analyse der Präsenz von externen Vorständen in den Aufsichtsräten deutscher Großunternehmen

Die Berufung externer Vorstände in das interne Kontrollgremium stellt eine gängige Praxis zwischen Großunternehmen dar. Insbesondere die deutsche Unternehmenslandschaft war über Jahrzehnte durch ein komplexes Netz personeller Verflechtungen über Vorstands- und Auf-sichtsratsgremien gekennzeichnet. In dem vorliegenden Beitrag werden erstmals systematisch unternehmensspezifische Faktoren für die Präsenz externer Vorstände in deutschen Aufsichtsräten und zeitliche Entwicklungstendenzen anhand eines aktuellen Datensatzes für den Zeitraum 1997 bis 2008 empirisch analysiert. Unter anderem nimmt die Präsenz externer Vorstände im Aufsichtsrat mit der Unternehmensgröße und dem Stimmrechtsanteil der Unternehmen aus dem untersuchten Datensatz zu. Die getrennte Auswertung unterschiedlicher Gruppen von externen Vorständen im Aufsichtsrat zeigt, dass externe Vorstandsvorsitzende im Vergleich zu anderen externen Vorstandsmitgliedern signifikant häufiger Mandate in erfolgreicheren, stärker diversifizierten sowie gelisteten Unternehmen ausüben. Schließlich wird der Einfluss der Kontrollvariablen auf die Präsenz externer Vorstände vor und nach der Reform des Steuerrechts im Jahr 2002 untersucht.The appointment of external managers to the supervisory board is common practice between large companies. During the past decades, German companies were linked by a dense network of personal linkages via executive and supervisory boards. Based on panel data for the period from 1997 to 2008 this paper empirically analyses trends and firm-specific factors that explain the presence of outside executives on the supervisory boards of large German companies. The results of the econometric estimations reveal a positive relation between company size and stock ownership of the companies in the sample and the presence of outside executives on the supervisory board. Separate estimations for the group of chairmen and regular executives on the executive committee show that chairmen are more likely to join the supervisory boards of more successful, diversified and listed companies. Finally, the analysis controls for the effect of the coefficients during the period before and the period following the tax reform in 2002 that enabled companies to sell large shareholdings without paying taxes for capital gains.