1,031 research outputs found
Economic importance of the Belgian ports: Flemish maritime ports, Liège port complex and the port of Brussels - Report 2009
This paper is an annual publication issued by the Microeconomic Analysis service of the National Bank of Belgium. The Flemish maritime ports (Antwerp, Ghent, Oostende, Zeebrugge), the Autonomous Port of Liège and the port of Brussels play a major role in their respective regional economies and in the Belgian economy, not only in terms of industrial activity but also as intermodal centres facilitating the commodity flow. This update paper provides an extensive overview of the economic importance and development of the Flemish maritime ports, the Liège port complex and the port of Brussels in the period 2004 - 2009, with an emphasis on 2009. Focusing on the three major variables of value added, employment and investment, the report also provides some information about social balance and the financial situation in these ports as a whole. These observations are linked to a more general context, along with a few cargo statistics. Annual accounts data from the Central Balance Sheet Office were used for the calculation of direct effects, the study of financial ratios and the analysis of the social balance sheet. The indirect effects of the activities concerned were estimated in terms of value added and employment, on the basis of data from the National Accounts Institute. In terms of maritime cargo traffic, the downturn recorded during the last quarter of 2008 continued throughout 2009. Direct value added declined in all the ports in Flanders. Maritime branches as a whole contracted. Only the value added of the maritime branches in the port of Ostend remained stable. The non-maritime branches as a whole saw a contraction in all the Flemish ports. It was the port of Antwerp that suffered the most from the drop in the value added. Its maritime branches shrank by nearly onethird. While the non-maritime branches were slightly down. The port of Ghent recorded a bigger decrease in the non-maritime branches. Conversely, the value added in the port of Zeebrugge fell more sharply in the maritime branches. Direct employment in the ports of Flanders as a whole declined during the year 2009. Except in Ghent, direct employment in the maritime branches fell in all the Flemish ports. Similarly, only one of them, the port of Ostend, recorded a rise in employment in the non-maritime branches. Thanks to this, it has been the only Flemish port to register direct employment growth. Investment decreased in all the ports in Flanders. The decline in investment was between one-sixth and one-fifth in the ports of Ghent, Antwerp and Zeebrugge. While Ostend recorded a cut of more than onethird in its investment levels in 2009. The volume of cargo handled in the port of Liège decreased strongly in 2009. Direct value added and employment registered a significant decline. Maritime and non-maritime branches were down for both value added and employement. Thanks to the "other services" branch of activity, investment rose steadily. The volume of cargo handled at the port of Brussels declined in 2009. Value added in this port remained steady. But employment contracted slightly. After the growth seen in 2008, investment was down by more than a quarter. This report provides a comprehensive account of these issues, giving details for each economic sector, although the comments are confined to the main changes that occurred in 2009
Constraining the fundamental parameters of the O-type binary CPD-41degr7733
Using a set of high-resolution spectra, we studied the physical and orbital
properties of the O-type binary CPD-41 7733, located in the core of \ngc. We
report the unambiguous detection of the secondary spectral signature and we
derive the first SB2 orbital solution of the system. The period is 5.6815 +/-
0.0015 d and the orbit has no significant eccentricity. CPD-41 7733 probably
consists of stars of spectral types O8.5 and B3. As for other objects in the
cluster, we observe discrepant luminosity classifications while using
spectroscopic or brightness criteria. Still, the present analysis suggests that
both components display physical parameters close to those of typical O8.5 and
B3 dwarfs. We also analyze the X-ray light curves and spectra obtained during
six 30 ks XMM-Newton pointings spread over the 5.7 d period. We find no
significant variability between the different pointings, nor within the
individual observations. The CPD-41 7733 X-ray spectrum is well reproduced by a
three-temperature thermal mekal model with temperatures of 0.3, 0.8 and 2.4
keV. No X-ray overluminosity, resulting e.g. from a possible wind interaction,
is observed. The emission of CPD-41 7733 is thus very representative of typical
O-type star X-ray emission.Comment: Accepted by ApJ, 15 pages, 9 figure
Magnetic stars from a FEROS cool Ap star survey
New magnetic Ap stars with split Zeeman components are presented. These stars were discovered from observations with the Fibre-fed Extended Range Optical Spectrograph (FEROS) spectrograph at the European Southern Observatory (ESO) 2.2-m telescope. 15 new magnetic stars are analysed here. Several stars with very strong magnetic fields were found, including HD 70702 with a 15-kG magnetic field strength, and HD 168767 with a 16.5-kG magnetic field strength measured using split Zeeman components of spectral lines and by comparison with synthetic calculations. The physical parameters of the stars were estimated from photometric and spectroscopic data. Together with previously published results for stars with strong magnetic fields, the relationship between magnetic field strength and rotation period is discussed
A generative framework for the study of delusions
Despite the ubiquity of delusional information processing in psychopathology and everyday life, formal characterizations of such inferences are lacking. In this article, we propose a generative framework that entails a computational mechanism which, when implemented in a virtual agent and given new information, generates belief updates (i.e., inferences about the hidden causes of the information) that resemble those seen in individuals with delusions. We introduce a particular form of Dirichlet process mixture model with a sampling-based Bayesian inference algorithm. This procedure, depending on the setting of a single parameter, preferentially generates highly precise (i.e. over-fitting) explanations, which are compartmentalized and thus can co-exist despite being inconsistent with each other. Especially in ambiguous situations, this can provide the seed for delusional ideation. Further, we show by simulation how the excessive generation of such over-precise explanations leads to new information being integrated in a way that does not lead to a revision of established beliefs. In all configurations, whether delusional or not, the inference generated by our algorithm corresponds to Bayesian inference. Furthermore, the algorithm is fully compatible with hierarchical predictive coding. By virtue of these properties, the proposed model provides a basis for the empirical study and a step toward the characterization of the aberrant inferential processes underlying delusions
Critical evaluation of magnetic field detections reported for pulsating B-type stars in the light of ESPaDOnS, Narval and reanalyzed FORS1/2 observations
Recent spectropolarimetric studies of 7 SPB and Cep stars have
suggested that photospheric magnetic fields are more common in B-type pulsators
than in the general population of B stars, suggesting a significant connection
between magnetic and pulsational phenomena. We present an analysis of new and
previously published spectropolarimetric observations of these stars. New
Stokes observations obtained with the high-resolution ESPaDOnS and Narval
instruments confirm the presence of a magnetic field in one of the stars
( Lup), but find no evidence of magnetism in 5 others. A re-analysis
of the published longitudinal field measurements obtained with the
low-resolution FORS1/2 spectropolarimeters finds that the measurements of all
stars show more scatter from zero than can be attributed to Gaussian noise,
suggesting the presence of a signal and/or systematic under-estimation of error
bars. Re-reduction and re-measurement of the FORS1/2 spectra from the ESO
archive demonstrates that small changes in reduction procedure lead to
substantial changes in the inferred longitudinal field, and substantially
reduces the number of field detections at the 3 level. Furthermore, we
find that the published periods are not unique solutions to the time series of
either the original or the revised FORS1/2 data. We conclude that the reported
field detections, proposed periods and field geometry models for Pyx,
15 CMa, 33 Eri and V1449 Aql are artefacts of the data analysis and reduction
procedures, and that magnetic fields at the reported strength are no more
common in SPB/ Cep stars than in the general population of B stars.Comment: 10 pages, 5 figures, accepted for publication in ApJ, 2012, typo
correcte
Spectropolarimetry of the Classical T Tauri Star TW Hydrae
We present high resolution (R ~ 60,000) circular spectropolarimetry of the
classical T Tauri star TW Hydrae. We analyze 12 photospheric absorption lines
and measure the net longitudinal magnetic field for 6 consecutive nights. While
no net polarization is detected the first five nights, a significant
photospheric field of Bz = 149 \pm 33 G is found on the sixth night. To rule
out spurious instrumental polarization, we apply the same analysis technique to
several non-magnetic telluric lines, detecting no significant polarization. We
further demonstrate the reality of this field detection by showing that the
splitting between right and left polarized components in these 12 photospheric
lines shows a linear trend with Lande g-factor times wavelength squared, as
predicted by the Zeeman effect. However, this longitudinal field detection is
still much lower than that which would result if a pure dipole magnetic
geometry is responsible for the mean magnetic field strength of 2.6 kG
previously reported for TW Hya. We also detect strong circular polarization in
the He I 5876 and the Ca II 8498 emission lines, indicating a strong field in
the line formation region of these features. The polarization of the Ca II line
is substantially weaker than that of the He I line, which we interpret as due
to a larger contribution to the Ca II line from chromospheric emission in which
the polarization signals cancel. However, the presence of polarization in the
Ca II line indicates that accretion shocks on Classical T Tauri stars do
produce narrow emission features in the infrared triplet lines of Calcium.Comment: One tar file. The paper has 22 pages, 5 figures. Accepted by AJ on
Sep 10, 200
Economic importance of the Belgian ports: Flemish maritime ports, Liège port complex and the port of Brussels: Report 2012
This paper is an annual publication issued by the Microeconomic Analysis service of the National Bank of Belgium. The Flemish maritime ports (Antwerp, Ghent, Ostend, Zeebrugge), the Autonomous Port of Liège and the port of Brussels play a major role in their respective regional economies and in the Belgian economy, not only in terms of industrial activity but also as intermodal centers facilitating the commodity flow.This update paper provides an extensive overview of the economic importance and development of the Flemish maritime ports, the Liège port complex and the port of Brussels for the period 2007-2012, with an emphasis on 2012. Focusing on the three major variables of value added, employment and investment, the report also provides some information based on the social balance sheet and an overview of the financial situation in these ports as a whole. These observations are linked to a more general context, along with a few cargo statistics. Annual accounts data from the Central Balance Sheet Office were used for the calculation of direct effects, the study of financial ratios and the analysis of the social balance sheet. The indirect effects of the activities concerned were estimated in terms of value added and employment, on the basis of data from the National Accounts Institute. As a result of the underlying calculation method the changes of indirect employment and indirect value added can differ from one another. (...) Following the 2009 decline and the improvement in 2011, maritime traffic in the Flemish ports began falling again in 2012. That applies to all the Flemish ports. Value added was rising in the maritime cluster of the Flemish ports and falling in the non-maritime cluster where trade and industry were in decline. Direct value added has risen in the ports of Antwerp and Ostend whereas it has fallen in the ports of Zeebrugge and Ghent. Conversely, direct employment was expanding in both clusters in the Flemish ports viewed as a whole and in each port taken individually. The decline in investment in the Flemish ports continued in 2012. That trend is evident in all the Flemish ports except the port of Ostend where investment was maintained in 2012
Economic importance of the Belgian ports: Flemish maritime ports, Liège port complex and the port of Brussels - Report 2015
This paper is an annual publication issued by the Microeconomic Analysis service of the National Bank of Belgium. The Flemish maritime ports (Antwerp, Ghent, Ostend, Zeebrugge), the Autonomous Port of Liège and the port of Brussels play a major role in their respective regional economies and in the Belgian economy, not only in terms of industrial activity but also as intermodal centers facilitating the commodity flow. This update paper1 provides an extensive overview of the economic importance and development of the Flemish maritime ports, the Liège port complex and the port of Brussels for the period 2010 - 2015, with an emphasis on 2015. Focusing on the three major variables of value added, employment and investment, the report also provides some information based on the social balance sheet and an overview of the financial situation in these ports as a whole. These observations are linked to a more general context, along with a few cargo statistics. Annual accounts data from the Central Balance Sheet Office were used for the calculation of direct effects, the study of financial ratios and the analysis of the social balance sheet. The indirect effects of the activities concerned were estimated in terms of value added and employment, on the basis of data from the National Accounts Institute. As a result of the underlying calculation method the changes of indirect employment and indirect value added can differ from one another. The developments concerning economic activity in the six ports in 2014 - 2015 are summarized in the table on the next page. In 2015 the growth of maritime traffic in the Flemish maritime ports was due to developments in the port of Antwerp and the port of Ghent. Direct value added increased in all Flemish maritime ports in 2015. However, direct employment is continuing to decline. Investment was down everywhere except in the port of Zeebrugge. Cargo traffic in the Liège port complex declined in 2015, whereas it slightly slowed down in the port of Brussels. At the same time, direct value added in Liège shrank while it rose sharply in the port of Brussels. By contrast, direct employment was down in both ports. This report provides a comprehensive account of these issues, giving details for each economic sector, although the comments are confined to the main changes that occurred in 2015
The Evolution of Blue Stragglers Formed Via Stellar Collisions
We have used the results of recent smoothed particle hydrodynamic simulations
of colliding stars to create models appropriate for input into a stellar
evolution code. In evolving these models, we find that little or no surface
convection occurs, precluding angular momentum loss via a magnetically-driven
stellar wind as a viable mechanism for slowing rapidly rotating blue stragglers
which have been formed by collisions. Angular momentum transfer to either a
circumstellar disk (possibly collisional ejecta) or a nearby companion are
plausible mechanisms for explaining the observed low rotation velocities of
blue stragglers. Under the assumption that the blue stragglers seen in NGC 6397
and 47 Tuc have been created solely by collisions, we find that the majority of
these blue stragglers cannot have been highly mixed by convection or meridional
circulation currents at anytime during their evolution. Also, on the basis of
the agreement between the predictions of our non-rotating models and the
observed blue straggler distribution, the evolution of blue stragglers is
apparently not dominated by the effects of rotation.Comment: 36 pages, including 1 table and 7 postscript figures (LaTeX2e). Also
avaliable at http://astrowww.phys.uvic.ca/~ouellet/ . Accepted for
publication in A
Incorporating structured text retrieval into the extended Boolean model
Conventional information retrieval models are inappropriate for use in databases containing semi-structured biographical data. A hybrid algorithm that effectively addresses many of the problems in searching biographical databases is presented in this article. An overview of applicable structured text retrieval algorithms is given, with focus specifically on the tree matching model. Small adaptations to the Extended Boolean Model, to make it more applicable to biographical databases, are described. The adaptation of tree matching models to the hierarchical nature of data in a person record is described and a distance function between query and record is defined. A hybrid model between the Extended Boolean Model and the adapted Tree Matching Model is then presented. A fast ranking algorithm appropriate for general searches and a more effective (but more resource intensive) algorithm for more advanced searches is given. It is shown how dates can be incorporated in the hybrid model to create a more powerful search algorithm. The hybrid algorithm can be used to rank records in descending order of relevance to a user's query
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