916 research outputs found
Prevention of fraud, corruption and bribery committed through legal entities for the purpose of financial and economic gain
In Dutch law there is no overall criminal offence on corruption. In Dutch criminal law corruption is divided in specific criminal offences which all have their own specific definition. Most corruption can be qualified as a criminal offence but it is sometimes difficult to qualify them as such. Qualifying in general as an offence is easy (forgery for example) but proving that the act specifically qualifies as corruption is harder. Given this general observation, a specific form of active corruption in the Dutch Criminal Code (DCC) seems relevant regarding to art. 2, par. 1, section a of the Framework Decision 2003/568/JHA of 22 July 2003 on combatting corruption in the private sector. Art. 328ter par. 2 of the DCC deals with bribery of a private person: punishable is the private person that gives or offers someone other than a civil servant, working in employement or acting as an agent, in exchange for something he has done or not done or will do or refrain from doing in the performance of his burden, a gift or promise, or a service of that nature or under such circumstances that he should reasonable assume that such a gift or promise will be withheld from his employer or principal contrary to good faith. This provision covers active corruption on the initiative of all private persons, including employees, managers and directors of private entities. However, this provision is limited to the bribery of employees and managers and seems to exclude the bribery of a director of a private entity. This means that this provision does not fully cover the obligation under art. 2, par. 1, section a of the Framework Decision 2003/568/JHA. In addition to art. 328ter DCC more general provisions can be used, especcially when the active corruption involves bribery of a director of a private entity. Dependant upon the circumstances of the case the provisions on forgery, falsifying of documents and cheating could be relevant. These circumstances should then involve: the forgery of a written statement with the intention to use this statement as genuine (art. 225 DCC), the falsification of stock certificates or other official certificates or documents, (art. 226 DCC) or the elements of cheating. In art. 326 of the DCC cheating is described as: the person who intentionally favours himself or another person in a unlawfull way, by using a false name, a false capacity, cunning manouvres or fabrications, moving another person to hand over a good, a service, information or a debt
A hybrid multiagent approach for global trajectory optimization
In this paper we consider a global optimization method for space trajectory design problems. The method, which actually aims at finding not only the global minimizer but a whole set of low-lying local minimizers(corresponding to a set of different design options), is based on a domain
decomposition technique where each subdomain is evaluated through a procedure based on the evolution of a population of agents. The method is applied to two space trajectory design problems and compared with existing deterministic and stochastic global optimization methods
Magnetic and Dynamic Properties of the Hubbard Model in Infinite Dimensions
An essentially exact solution of the infinite dimensional Hubbard model is
made possible by using a self-consistent mapping of the Hubbard model in this
limit to an effective single impurity Anderson model. Solving the latter with
quantum Monte Carlo procedures enables us to obtain exact results for the one
and two-particle properties of the infinite dimensional Hubbard model. In
particular we find antiferromagnetism and a pseudogap in the single-particle
density of states for sufficiently large values of the intrasite Coulomb
interaction at half filling. Both the antiferromagnetic phase and the
insulating phase above the N\'eel temperature are found to be quickly
suppressed on doping. The latter is replaced by a heavy electron metal with a
quasiparticle mass strongly dependent on doping as soon as . At half
filling the antiferromagnetic phase boundary agrees surprisingly well in shape
and order of magnitude with results for the three dimensional Hubbard model.Comment: 32 page
Mesoscopic mean-field theory for spin-boson chains in quantum optical systems
We present a theoretical description of a system of many spins strongly coupled to a bosonic chain. We rely on the use of a spin-wave theory describing the Gaussian fluctuations around the mean-field solution, and focus on spin-boson chains arising as a generalization of the Dicke Hamiltonian. Our model is motivated by experimental setups such as trapped ions, or atoms/qubits coupled to cavity arrays. This situation corresponds to the cooperative (E⊗β) Jahn-Teller distortion studied in solid-state physics. However, the ability to tune the parameters of the model in quantum optical setups opens up a variety of novel intriguing situations. The main focus of this paper is to review the spin-wave theoretical description of this problem as well as to test the validity of mean-field theory. Our main result is that deviations from mean-field effects are determined by the interplay between magnetic order and mesoscopic cooperativity effects, being the latter strongly size-dependent
Star Formation in the Starburst Cluster in NGC 3603
We have used new, deep, visible and near infrared observations of the compact
starburst cluster in the giant HII region NGC 3603 and its surroundings with
the WFC3 on HST and HAWK-I on the VLT to study in detail the physical
properties of its intermediate mass (~ 1 - 3 M_sun) stellar population. We show
that after correction for differential extinction and actively accreting stars,
and the study of field star contamination, strong evidence remains for a
continuous spread in the ages of pre-main sequence stars in the range ~ 2 to ~
30 Myr within the temporal resolution available. Existing differences among
presently available theoretical models account for the largest possible
variation in shape of the measured age histograms within these limits. We also
find that this isochronal age spread in the near infrared and visible
Colour-Magnitude Diagrams cannot be reproduced by any other presently known
source of astrophysical or instrumental scatter that could mimic the luminosity
spread seen in our observations except, possibly, episodic accretion. The
measured age spread and the stellar spatial distribution in the cluster are
consistent with the hypothesis that star formation started at least 20-30 Myrs
ago progressing slowly but continuously up to at least a few million years ago.
All the stars in the considered mass range are distributed in a flattened
oblate spheroidal pattern with the major axis oriented in an approximate
South-East - North-West direction, and with the length of the equatorial axis
decreasing with increasing age. This asymmetry is most likely due to the fact
that star formation occurred along a filament of gas and dust in the natal
molecular cloud oriented locally in this direction.Comment: 21 pages, 19 figures, accepted for publication in Astrophysics &
Space Scienc
Panspermia, Past and Present: Astrophysical and Biophysical Conditions for the Dissemination of Life in Space
Astronomically, there are viable mechanisms for distributing organic material
throughout the Milky Way. Biologically, the destructive effects of ultraviolet
light and cosmic rays means that the majority of organisms arrive broken and
dead on a new world. The likelihood of conventional forms of panspermia must
therefore be considered low. However, the information content of dam-aged
biological molecules might serve to seed new life (necropanspermia).Comment: Accepted for publication in Space Science Review
Low-mass pre--main-sequence stars in the Magellanic Clouds
[Abridged] The stellar Initial Mass Function (IMF) suggests that sub-solar
stars form in very large numbers. Most attractive places for catching low-mass
star formation in the act are young stellar clusters and associations, still
(half-)embedded in star-forming regions. The low-mass stars in such regions are
still in their pre--main-sequence (PMS) evolutionary phase. The peculiar nature
of these objects and the contamination of their samples by the evolved
populations of the Galactic disk impose demanding observational techniques for
the detection of complete numbers of PMS stars in the Milky Way. The Magellanic
Clouds, the companion galaxies to our own, demonstrate an exceptional star
formation activity. The low extinction and stellar field contamination in
star-forming regions of these galaxies imply a more efficient detection of
low-mass PMS stars than in the Milky Way, but their distance from us make the
application of special detection techniques unfeasible. Nonetheless, imaging
with the Hubble Space Telescope yield the discovery of solar and sub-solar PMS
stars in the Magellanic Clouds from photometry alone. Unprecedented numbers of
such objects are identified as the low-mass stellar content of their
star-forming regions, changing completely our picture of young stellar systems
outside the Milky Way, and extending the extragalactic stellar IMF below the
persisting threshold of a few solar masses. This review presents the recent
developments in the investigation of PMS stars in the Magellanic Clouds, with
special focus on the limitations by single-epoch photometry that can only be
circumvented by the detailed study of the observable behavior of these stars in
the color-magnitude diagram. The achieved characterization of the low-mass PMS
stars in the Magellanic Clouds allowed thus a more comprehensive understanding
of the star formation process in our neighboring galaxies.Comment: Review paper, 26 pages (in LaTeX style for Springer journals), 4
figures. Accepted for publication in Space Science Review
Optimization of Interplanetary Rendezvous Trajectories for Solar Sailcraft Using a Neurocontroller
As for all low-thrust spacecraft, finding optimal solar sailcraft trajectories is a difficult and time-consuming task that involves a lot of experience and expert knowledge, since the convergence behavior of optimizers that are based on numerical optimal control methods depends strongly on an adequate initial guess, which is often hard to find. Even if the op-timizer converges to an ”optimal trajectory”, this trajectory is typically close to the initial guess that is rarely close to the global optimum. This paper demonstrates, that artificial neural networks in combination with evolutionary algorithms can be applied successfully for optimal solar sailcraft steering. Since these evolutionary neurocontrollers explore the trajectory search space more exhaustively than a human expert can do by using tradi-tional optimal control methods, they are able to find steering strategies that generate better trajectories, which are closer to the global optimum. Results are presented for a Near Earth Asteroid rendezvous mission and for a Mercury rendezvous mission
Interstellar MHD Turbulence and Star Formation
This chapter reviews the nature of turbulence in the Galactic interstellar
medium (ISM) and its connections to the star formation (SF) process. The ISM is
turbulent, magnetized, self-gravitating, and is subject to heating and cooling
processes that control its thermodynamic behavior. The turbulence in the warm
and hot ionized components of the ISM appears to be trans- or subsonic, and
thus to behave nearly incompressibly. However, the neutral warm and cold
components are highly compressible, as a consequence of both thermal
instability in the atomic gas and of moderately-to-strongly supersonic motions
in the roughly isothermal cold atomic and molecular components. Within this
context, we discuss: i) the production and statistical distribution of
turbulent density fluctuations in both isothermal and polytropic media; ii) the
nature of the clumps produced by thermal instability, noting that, contrary to
classical ideas, they in general accrete mass from their environment; iii) the
density-magnetic field correlation (or lack thereof) in turbulent density
fluctuations, as a consequence of the superposition of the different wave modes
in the turbulent flow; iv) the evolution of the mass-to-magnetic flux ratio
(MFR) in density fluctuations as they are built up by dynamic compressions; v)
the formation of cold, dense clouds aided by thermal instability; vi) the
expectation that star-forming molecular clouds are likely to be undergoing
global gravitational contraction, rather than being near equilibrium, and vii)
the regulation of the star formation rate (SFR) in such gravitationally
contracting clouds by stellar feedback which, rather than keeping the clouds
from collapsing, evaporates and diperses them while they collapse.Comment: 43 pages. Invited chapter for the book "Magnetic Fields in Diffuse
Media", edited by Elisabete de Gouveia dal Pino and Alex Lazarian. Revised as
per referee's recommendation
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