5,196 research outputs found
The growth of business groups by habitual entrepreneurs: the role of entrepreneurial teams
Previous research demonstrates that entrepreneurial processes underpin the growth of business groups. A business group is a set of companies controlled by the same entrepreneur. Case studies of portfolio entrepreneurs suggest that one of the main reasons for business group formation is the need to create an entrepreneurial team, which is achieved by giving minority shares in the new ventures to others, mainly former employees. This enhances the portfolio entrepreneur’s ability to grow and diversify the businesses under their control. The paper identifies and discusses the different types of entrepreneurial teams developed by portfolio entrepreneurs, and their dynamics.Business groups, entrepreneurship, entrepreneurial teams
Numerical methods for computing Casimir interactions
We review several different approaches for computing Casimir forces and
related fluctuation-induced interactions between bodies of arbitrary shapes and
materials. The relationships between this problem and well known computational
techniques from classical electromagnetism are emphasized. We also review the
basic principles of standard computational methods, categorizing them according
to three criteria---choice of problem, basis, and solution technique---that can
be used to classify proposals for the Casimir problem as well. In this way,
mature classical methods can be exploited to model Casimir physics, with a few
important modifications.Comment: 46 pages, 142 references, 5 figures. To appear in upcoming Lecture
Notes in Physics book on Casimir Physic
On the Conjecture of Kochar and Korwar
In this paper, we solve for some cases a conjecture by Kochar and Korwar (1996) in
relation with the normalized spacings of the order statistics related to a sample of
independent exponential random variables with different scale parameter. In the case of
a sample of size n=3, they proved the ordering of the normalized spacings and
conjectured that result holds for all n. We give the proof of this conjecture for n=4 and
for both spacing and normalized spacings. We also generalize some results to n>
On identifiability of MAP processes
Two types of transitions can be found in the Markovian Arrival process or MAP: with
and without arrivals. In transient transitions the chain jumps from one state to another
with no arrival; in effective transitions, a single arrival occurs. We assume that in
practice, only arrival times are observed in a MAP. This leads us to define and study the
Effective Markovian Arrival process or E-MAP. In this work we define identifiability of
MAPs in terms of equivalence between the corresponding E-MAPs and study conditions
under which two sets of parameters induce identical laws for the observable process, in
the case of 2 and 3-states MAP. We illustrate and discuss our results with examples
Bayesian inference and prediction for the GI/M/1 queueing system
This article undertake Bayesian inference and prediction for GI/M/1 queueing systems. A semiparametric model based on mixtures of Erlang distributions is considered to model the general interarrival time distribution. Given arrival and service data, a Bayesian procedure based on birth-death Markov Chain Monte Carlo methods is proposed. An estimation of the system parameters and predictive distributions of measures such as the stationary system size and waiting time is give
Bayesian estimation for the M/G/1 queue using a phase type approximation
This article deals with Bayesian inference and prediction for M/G/1 queueing systems. The general service time density is approximated with a class of Erlang mixtures which are phase type distributions. Given this phase type approximation, an explicit evaluation of measures such as the stationary queue size, waiting time and busy period distributions can be obtained. Given arrival and service data, a Bayesian procedure based on reversible jump Markov Chain Monte Carlo methods is proposed to estimate system parameters and predictive distributions
- …