5,355 research outputs found
Improved Sequential Stopping Rule for Monte Carlo Simulation
This paper presents an improved result on the negative-binomial Monte Carlo
technique analyzed in a previous paper for the estimation of an unknown
probability p. Specifically, the confidence level associated to a relative
interval [p/\mu_2, p\mu_1], with \mu_1, \mu_2 > 1, is proved to exceed its
asymptotic value for a broader range of intervals than that given in the
referred paper, and for any value of p. This extends the applicability of the
estimator, relaxing the conditions that guarantee a given confidence level.Comment: 2 figures. Paper accepted in IEEE Transactions on Communication
On global location-domination in graphs
A dominating set of a graph is called locating-dominating, LD-set for
short, if every vertex not in is uniquely determined by the set of
neighbors of belonging to . Locating-dominating sets of minimum
cardinality are called -codes and the cardinality of an LD-code is the
location-domination number . An LD-set of a graph is global
if it is an LD-set of both and its complement . The global
location-domination number is the minimum cardinality of a
global LD-set of . In this work, we give some relations between
locating-dominating sets and the location-domination number in a graph and its
complement.Comment: 15 pages: 2 tables; 8 figures; 20 reference
M&AS performance in the European financial industry
This paper looks at the performance record of M&As that took place in the European Union financial industry in the period 1998-2002. First, the paper reports evidence on shareholder returns from mergers. Merger announcements brought positive excess returns to the shareholders of the target company around the date of the announcement, with a slight positive excess return in the 3-month period prior to announcement. Returns to shareholders of the acquiring firms were essentially zero around announcement. One year after the announcement, excess returns were not significantly different from zero for either targets or acquirers. The paper also provides evidence on changes in operating performance for the subsample of mergers involving banks. M&As usually involved targets with lower-than-average operating performance for their sector. The transactions resulted in significant improvements in the target banks' performance, beginning on average two years after the transaction was completed. Return on equity of the target companies increased by an average of 7%, and the same firms also experienced efficiency improvements.mergers and acquisitions; financial industry;
Value creation in European M&As.
This paper looks at the value generated to shareholders by the announcement of mergers and acquisitions involving firms in the European Union. Target firm shareholders receive on average a statistically significant excess return of 9%. Acquirers' excess returns are null on average. Excess returns differ significantly depending on whether the merger involves two firms from the same European country or is a cross-border transaction. Cross-border transactions generate less total value than national mergers. Furthermore, when a cross-border merger occurs in an industry in which governments historically have been actively involved, the transaction results in a net destruction of value to shareholders.Cross-border mergers; shareholder returns; value creation; regulation
On the local Lorentz invariance in N=1 supergravity
We discuss the local Lorentz invariance in the context of N=1 supergravity
and show that a previous attempt to find explicit solutions to the Lorentz
constraint in terms of matrices is not correct. We improve that
solution by using a different representation of the Lorentz operators in terms
of the generators of the rotation group, and show its compatibility with the
matrix representation of the fermionic field. We find the most general wave
functional that satisfies the Lorentz constraint in this representation
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