6,732 research outputs found
Benchmarking best manufacturing practices: a study into four sectors of Turkish industry
Reports on a benchmarking study conducted to quantify how well companies operating in various sectors of Turkish industry match up to best practice, both in the practices they adopt and in the operational outcomes that result, and to test the hypothesis that the closer a company is to best practice, the more likely it is for that company to achieve higher business performance. The survey conducted in 1997 and 1998 included 82 companies from the Turkish electronics, cement, automotive sectors and part and component suppliers to the appliance industry. For data gathering. employs the Competitive Strategies and Best Practices Benchmarking Questionnaire, supported ly, some follow-up interviews and one-day site visits. Classifies two small groups of companies as leaders and laggers, depending on how close they were to best practice. Shows that the leaders have performed better than the laggers in adopting best manufacturing practices and in the achievement of high performance La,els. The leaders also have achieved substantially higher business performance than the laggers. Furthermore, observes that large-sized companies outperform the rest both in terms of their success in implementing best manufacturing practices and in achieving high operational outcomes and that there is no appreciable difference between industrial sectors in implementing best manufacturing practices and in achieving high operational outcomes
Some Fundamental Properties of a Multivariate von Mises Distribution
In application areas like bioinformatics multivariate distributions on angles
are encountered which show significant clustering. One approach to statistical
modelling of such situations is to use mixtures of unimodal distributions. In
the literature (Mardia et al., 2011), the multivariate von Mises distribution,
also known as the multivariate sine distribution, has been suggested for
components of such models, but work in the area has been hampered by the fact
that no good criteria for the von Mises distribution to be unimodal were
available. In this article we study the question about when a multivariate von
Mises distribution is unimodal. We give sufficient criteria for this to be the
case and show examples of distributions with multiple modes when these criteria
are violated. In addition, we propose a method to generate samples from the von
Mises distribution in the case of high concentration.Comment: fixed a typo in the article title, minor fixes throughou
Inverse Anticipating Synchronization
We report a new type of chaos synchronization:inverse anticipating
synchronization, where a time delay chaotic system can drive another system in
such a way that the driven system anticipates the driver by synchronizing with
its inverse future state. We extend the concept of inverse anticipating chaos
synchronization to cascaded systems. We propose means for the experimental
observation of inverse anticipating chaos synchronization in external cavity
lasers.Comment: LaTex 6 pages, resubmitted to PR
Localized versus delocalized states: Photoluminescence from electrochemically synthesized ZnO nanowires
We analyze the near-band-edge photoluminescence of electrochemically deposited ZnO nanowires and directly correlate the photoluminescence properties with the carrier concentration in the nanowires as determined from electrochemical impedance spectroscopy. We find a donor density of 81019 cm−3 in the as-deposited nanowires and show that the near-band-edge emission results from band-to-band recombination processes delocalized states. A photoluminescence band centered at 3.328 eV scales with the diameter of the nanowires and is assigned to recombination processes involving surface states. We show that annealing at 500 °C in air reduces the donor density in the nanowires by more than one order of magnitude, leading to sharp excitonic transitions in the electrochemically deposited nanowire
The galactic population of white dwarfs
Original paper can be found at: http://www.iop.org/EJ/conf DOI: 10.1088/1742-6596/172/1/012004 [16th European White Dwarfs Workshop]The contribution of white dwarfs of the different Galactic populations to the stellar content of our Galaxy is only poorly known. Some authors claim a vast population of halo white dwarfs, which would be in accordance with some investigations of the early phases of Galaxy formation claiming a top-heavy initial– mass– function. Here, I present a model of the population of white dwarfs in the Milky Way based on observations of the local white dwarf sample and a standard model of Galactic structure. This model will be used to estimate the space densities of thin disc, thick disc and halo white dwarfs and their contribution to the baryonic mass budget of the Milky Way. One result of this investigation is that white dwarfs of the halo population contribute a large fraction of the Galactic white dwarf number count, but they are not responsible for the lion's share of stellar mass in the Milky Way. Another important result is the substantial contribution of the – often neglected – population of thick disc white dwarfs. Misclassification of thick disc white dwarfs is responsible for overestimates of the halo population in previous investigations.Peer reviewe
FRAP measurements after targeted irradiation of heterochromatin and euchromatin at the GSI microbeam
Layer Features of the Lattice Gas Model for Self-Organized Criticality
A layer-by-layer description of the asymmetric lattice gas model for
1/f-noise suggested by Jensen [Phys. Rev. Lett. 64, 3103 (1990)] is presented.
The power spectra of the lattice layers in the direction perpendicular to the
particle flux is studied in order to understand how the white noise at the
input boundary evolves, on the average, into 1/f-noise for the system. The
effects of high boundary drive and uniform driving force on the power spectrum
of the total number of diffusing particles are considered. In the case of
nearest-neighbor particle interactions, high statistics simulation results show
that the power spectra of single lattice layers are characterized by different
exponents such that as one approaches the outer
boundary.Comment: LaTeX, figures upon reques
The PANDA GEM-based TPC Prototype
We report on the development of a GEM-based TPC prototype for the PANDA
experiment. The design and requirements of this device will be illustrated,
with particular emphasis on the properties of the recently tested GEM-detector,
the characterization of the read-out electronics and the development of the
tracking software that allows to evaluate the GEM-TPC data.Comment: submitted to NIMA 4 pages, 6 picture
Metastability in Josephson transmission lines
Thermal activation and macroscopic quantum tunneling in current-biased
discrete Josephson transmission lines are studied theoretically. The degrees of
freedom under consideration are the phases across the junctions which are
coupled to each other via the inductances of the system. The resistively
shunted junctions that we investigate constitute a system of N interacting
degrees of freedom with an overdamped dynamics. We calculate the decay rate
within exponential accuracy as a function of temperature and current. Slightly
below the critical current, the decay from the metastable state occurs via a
unique ("rigid") saddlepoint solution of the Euclidean action describing the
simultaneous decay of the phases in all the junctions. When the current is
reduced, a crossover to a regime takes place, where the decay occurs via an
"elastic" saddlepoint solution and the phases across the junctions leave the
metastable state one after another. This leads to an increased decay rate
compared with the rigid case both in the thermal and the quantum regime. The
rigid-to-elastic crossover can be sharp or smooth analogous to first- or
second- order phase transitions, respectively. The various regimes are
summarized in a current-temperature decay diagram.Comment: 11 pages, RevTeX, 3 PS-figures, revised versio
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