pinecone/core-2020-05-10-deduplication huggingface dataset:
The Maximum Mass of Star Clusters

When an universal untruncated star cluster initial mass function (CIMF) described by a power-law distribution is assumed, the mass of the most massive star cluster in a galaxy (M_max) is the result of the size-of-sample (SoS) effect. This implies a dependence of M_max on the total number of star clusters (N). The SoS effect also implies that M_max within a cluster population increases with equal logarithmic intervals of age. This is because the number of clusters formed in logarithmic age intervals increases (assuming a constant cluster formation rate). This effect has been observed in the SMC and LMC. Based on the maximum pressure (P_int) inside molecular clouds, it has been suggested that a physical maximum mass (M_max[phys]) should exist. The theory predicts that M_max[phys] should be observable, i.e. lower than M_max that follows from statistical arguments, in big galaxies with a high star formation rate. We compare the SoS relations in the SMC and LMC with the ones in M51 and model the integrated cluster luminosity function (CLF) for two cases: 1) M_max is determined by the SoS effect and 2) M_max=M_max[phys]=constant. The observed CLF of M51 and the comparison of the SoS relations with the SMC and LMC both suggest that there exists a M_max[phys] of 5*10^5 M_sun in M51. The CLF of M51 looks very similar to the one observed in the ``Antennae'' galaxies. A direct comparison with our model suggests that there M_max[phys]=2*10^6 M_sun
The radii of thousands of star clusters in M51 with HST/ACS

We exploit the superb resolution of the new HST/ACS mosaic image of M51 to select a large sample of young (< 1 Gyr) star clusters in the spiral disk, based on their sizes. The image covers the entire spiral disk in B, V, I and H_alpha, at a resolution of 2 pc per pixel. The surface density distribution of 4357 resolved clusters shows that the clusters are more correlated with clouds than with stars, and we find a hint of enhanced cluster formation at the corotation radius. The radius distribution of a sample of 769 clusters with more accurate radii suggests that young star clusters have a preferred effective radius of ~3 pc, which is similar to the preferred radius of the much older GCs. However, in contrast to the GCs, the young clusters in M51 do not show a relation between radius and galactocentric distance. This means that the clusters did not form in tidal equilibrium with their host galaxy, nor that their radius is related to the ambient pressure
Good News for MOS, MXU & Co. - The New Spectroscopic Pipeline for the
  FORSes

Since October 1, 2006, spectroscopic data from the two FORS instruments have
been reduced with a new pipeline, which is based on a bottom-up calibration
approach. I give a short description of the pipeline and discuss first
experiences with automatic data reduction using this software, which has
significantly increased the percentage of processed data for both instruments.
I will also describe possible new options for Quality Control.Comment: 6 pages, 6 Postscript figures, uses svmult.cls (included), to appear
  in the proceedings of the 2007 ESO Instrument Calibration Worksho
Integral Field Spectrographs: a user's view

We easily tend to think of Integral-Field Spectrographs (IFS) along two
opposing trends: as either the beautiful combination between photometry and
spectroscopy, or as our worst nightmare including the dark side of both worlds.
I favour a view where each IFS is considered individually, as one instrument
with specific performances which can be used optimally for a certain range of
scientific programs. It is indeed true that data-wise, IFS do sometime merge
the characteristics of classic (e.g., long-slit) spectrographs with annoying
issues associated with Imagers. This is in fact the price to pay to access a
drastically different perspective of our favourite targets. The challenge is
then to provide the necessary tools to properly handle the corresponding data.
However, this should certainly not be thought as something specific to IFS:
such a challenge should be accepted for any instrument, and most importantly
solved prior to its delivery at the telescope.Comment: 6 pages, 2 figures. Invited talk, to appear in the Proceedings of
  "The 2007 ESO Instrument Calibration Workshop", ESO Astrophysics Symposia,
  Springe
A new Generation of Spectrometer Calibration Techniques based on Optical
  Frequency Combs

Typical astronomical spectrographs have a resolution ranging between a few
hundred to 200.000. Deconvolution and correlation techniques are being employed
with a significance down to 1/1000 th of a pixel. HeAr and ThAr lamps are
usually used for calibration in low and high resolution spectroscopy,
respectively. Unfortunately, the emitted lines typically cover only a small
fraction of the spectrometer's spectral range. Furthermore, their exact
position depends strongly on environmental conditions. A problem is the strong
intensity variation between different (intensity ratios {>300). In addition,
the brightness of the lamps is insufficient to illuminate a spectrograph via an
integrating sphere, which in turn is important to calibrate a long-slit
spectrograph, as this is the only way to assure a uniform illumination of the
spectrograph pupil.
  Laboratory precision laser spectroscopy has experienced a major advance with
the development of optical frequency combs generated by pulsed femto-second
lasers. These lasers emit a broad spectrum (several hundred nanometers in the
visible and near infra-red) of equally-spaced "comb" lines with almost uniform
intensity (intensity ratios typically <10). Self-referencing of the laser
establishes a precise ruler in frequency space that can be stabilized to the
10e-18 uncertainty level, reaching absolute frequency inaccuracies at the
10e-12 level per day when using the Global Positioning System's (GPS) time
signal as the reference. The exploration of the merits of this new technology
holds the promise for broad-band, highly accurate and reproducible calibration
required for reliable operation of current and next generation astronomic
spectrometers.Comment: will be published in the proceedings of "The 2007 ESO Instrument
  Calibration Workshop", Springer-Verlag series "ESO Astrophysics Symposia
AMBER on the VLTI: data processing and calibration issues

We present here the current performances of the AMBER / VLTI instrument for
standard use and compare these with the offered modes of the instrument. We
show that the instrument is able to reach its specified precision only for
medium and high spectral resolution modes, differential observables and bright
objects. For absolute observables, the current achievable accuracy is strongly
limited by the vibrations of the Unit Telescopes, and also by the observing
procedure which does not take into account the night-long transfer function
monitoring. For low-resolution mode, the current limitation is more in the data
reduction side, since several effects negligible at medium spectral resolution
are not taken into account in the current pipeline. Finally, for faint objects
(SNR around 1 per spectral channel), electromagnetic interferences in the VLTI
interferometric laboratory with the detector electronics prevents currently to
get unbiased measurements. Ideas are under study to correct in the data
processing side this effect, but a hardware fix should be investigated
seriously since it limits seriously the effective limiting magnitude of the
instrument.Comment: 10 page
VIMOS total transmission profiles for broad-band filters

VIMOS is a wide-field imager and spectrograph mounted on UT3 at the
  VLT, whose FOV consists of four 7'x8' quadrants. Here we present the
measurements of total transmission profiles -- i.e. the throughput of telescope
+ instrument -- for the broad band filters U, B, V, R, I, and z for each of its
four quadrants. Those measurements can also be downloaded from the public VIMOS
web-page. The transmission profiles are compared with previous estimates from
the VIMOS consortium.Comment: 5 pages, 3 figures, to appear in the proceedings of the ESO
  instrument calibration workshop 2007, Springer Verlag series "ESO
  Astrophysics Symposia", eds. F. Kerber & A. Kaufe
The Garching-Bonn Deep Survey (GaBoDS) Wide-Field-Imaging Reduction
  Pipeline

We introduce our publicly available Wide-Field-Imaging reduction pipeline
THELI. The procedures applied for the efficient pre-reduction and astrometric
calibration are presented. A special emphasis is put on the methods applied to
the photometric calibration. As a test case the reduction of optical data from
the ESO Deep Public Survey including the WFI-GOODS data is described. The
end-products of this project are now available via the ESO archive Advanced
Data Products section.Comment: 6 pages, 3 figures, proceedings of ESO Calibration Workshop 200
SkyMapper and the Southern Sky Survey - a resource for the southern sky

SkyMapper is amongst the first of a new generation of dedicated, wide-field
survey telescopes. The 1.3m SkyMapper telescope features a 5.7 square degree
field-of-view Cassegrain imager and will see first light in late 2007. The
primary goal of the facility is to conduct the Southern Sky Survey a six
colour, six epoch survey of the southern sky. The survey will provide
photometry for objects between 8th and 23rd magnitude with global photometric
accuracy of 0.03 magnitudes and astrometry to 50 mas. This will represent a
valuable scientific resource for the southern sky and in addition provide a
basis for photometric and astrometric calibration of imaging data.Comment: 6 pages, 4 figures, proceedings of ESO Calibration Workshop 200
Turning Points in the Evolution of Isolated Neutron Stars' Magnetic Fields

During the life of isolated neutron stars (NSs) their magnetic field passes through a variety of evolutionary phases. Depending on its strength and structure and on the physical state of the NS (e.g. cooling, rotation), the field looks qualitatively and quantitatively different after each of these phases. Three of them, the phase of MHD instabilities immediately after NS's birth, the phase of fallback which may take place hours to months after NS's birth, and the phase when strong temperature gradients may drive thermoelectric instabilities, are concentrated in a period lasting from the end of the proto--NS phase until 100, perhaps 1000 years, when the NS has become almost isothermal. The further evolution of the magnetic field proceeds in general inconspicuous since the star is in isolation. However, as soon as the product of Larmor frequency and electron relaxation time, the so-called magnetization parameter, locally and/or temporally considerably exceeds unity, phases, also unstable ones, of dramatic changes of the field structure and magnitude can appear. An overview is given about that field evolution phases, the outcome of which makes a qualitative decision regarding the further evolution of the magnetic field and its host NS
The theory of pulsar winds and nebulae

We review current theoretical ideas on pulsar winds and their surrounding nebulae. Relativistic MHD models of the wind of the aligned rotator, and of the striped wind, together with models of magnetic dissipation are discussed. It is shown that the observational signature of this dissipation is likely to be point-like, rather than extended, and that pulsed emission may be produced. The possible pulse shapes and polarisation properties are described. Particle acceleration at the termination shock of the wind is discussed, and it is argued that two distinct mechanisms must be operating, with the first-order Fermi mechanism producing the high-energy electrons (above 1 TeV) and either magnetic annihilation or resonant absorption of ion cyclotron waves responsible for the 100 MeV to 1 TeV electrons. Finally, MHD models of the morphology of the nebula are discussed and compared with observation
Toward Non-parallelizable Client Puzzles

Client puzzles have been proposed as a useful mechanism for mitigating denial of service attacks on network protocols. Several different puzzles have been proposed in recent years. This paper reviews the desirable properties of client puzzles, pointing out that there is currently no puzzle which satisfies all such properties. We investigate how to provide the property of non-parallelizability in a practical puzzle. After showing that obvious ideas based on hash chains have significant problems, we propose a new puzzle based on the subset sum problem. Despite some practical implementation issues, this is the first example that satisfies all the desirable properties for a client puzzle
On tree pattern query rewriting using views

We study and present our findings on two closely related  problems on xpath rewriting using views when both the view and the  query are tree patterns involving /,// and []. First, given view V and  query Q, is it possible for Q to have an equivalent rewriting using V  which is the union of two or more tree patterns, but not an equivalent  rewriting which is a single pattern? This problem is of both theoretical  and practical importance because, if the answer is no, then, to answer a  query completely using the views, we should use more efficient methods,  such as the PTIME algorithm of [13], to find the equivalent rewriting,  rather than try to find the union of all contained rewritings and test its  equivalence to Q. Second, given a set V of views, we want to know under  what conditions a subset V  of the views are redundant in the sense that  for any query Q, the contained rewritings of Q using the views in V   are contained in those using the views in V -V . Solving this problem  can help us to, for example, choose the minimum number of views to  be cached, or better design the virtual schema in a mediated data integration  system, or avoid repeated calculation in query optimization.  We provide necessary and sufficient conditions for the second problem,  based on answers to the first problem. When the views produce comparable  answers, we extend our findings to include the case where the  intersection of views, in addition to the individual views, are used in the  rewriting.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Bias reduction in traceroute sampling: towards a more accurate map of
  the Internet

Traceroute sampling is an important technique in exploring the internet
router graph and the autonomous system graph. Although it is one of the primary
techniques used in calculating statistics about the internet, it can introduce
bias that corrupts these estimates. This paper reports on a theoretical and
experimental investigation of a new technique to reduce the bias of traceroute
sampling when estimating the degree distribution. We develop a new estimator
for the degree of a node in a traceroute-sampled graph; validate the estimator
theoretically in Erdos-Renyi graphs and, through computer experiments, for a
wider range of graphs; and apply it to produce a new picture of the degree
distribution of the autonomous system graph.Comment: 12 pages, 3 figure
Determining factors behind the PageRank log-log plot

We study the relation between PageRank and other parameters of information
networks such as in-degree, out-degree, and the fraction of dangling nodes. We
model this relation through a stochastic equation inspired by the original
definition of PageRank. Further, we use the theory of regular variation to
prove that PageRank and in-degree follow power laws with the same exponent. The
difference between these two power laws is in a multiple coefficient, which
depends mainly on the fraction of dangling nodes, average in-degree, the power
law exponent, and damping factor. The out-degree distribution has a minor
effect, which we explicitly quantify. Our theoretical predictions show a good
agreement with experimental data on three different samples of the Web
Can Brotherhood be Sold Like Soap…Online? An Online Social Marketing and Advocacy Pilot Study Synopsis

Having engaged one billion users by early 2006, the Internet is the world’s fastest-growing mass communications medium. As it permeates into countless lives across the planet, it offers social campaigners an opportunity to deploy interactive interventions that encourage populations to adopt healthy living, environmental protection and community development behaviours. Using a classic set of social campaigning criteria, this paper explores relationships between social campaign websites and behavioural change
Enforcing Policies and Guidelines in Web Portals: A Case Study

Customizability is generally considered a desirable feature of web portals. However, if left uncontrolled, customizability may come at the price of lack of uniformity or lack of maintainability. Indeed, as the portal content and services evolve, they can break assumptions made in the definition of customized views. Also, uncontrolled customization may lead to certain content considered important by the web portal owners (e.g. advertisements), to not be displayed to end users. Thus, web portal customization is hindered by the need to enforce customization policies and guidelines with minimal overhead. This paper presents a case study where a combination of techniques was employed to semi-automatically enforce policies and guidelines on community-built presentation components in a web portal. The study shows that a combination of automated verification and semantics extraction techniques can reduce the amount of manual checks required to enforce these policies and guidelines
Predicting the Short-Term Market Reaction to Asset Specific News: Is Time Against Us?

The efficient market hypothesis states that investors immediately incorporate all available information into the price of an asset to accurately reflect its value at any given time.  The sheer volume of information immediately available electronically makes it difficult for a single investor to keep abreast of all information for a single stock, let alone multiple.  We aim to determine how quickly investors tend to react to asset specific news by analysing the accuracy of classifiers which take the content of news to predict the short-term market reaction.  The faster the market reacts to news the more cost-effective it becomes to employ content analysis techniques to aid the decisions of traders.  We find that the best results are achieved by allowing investors in the US 90 minutes to react to news.  In the UK and Australia the best results are achieved by allowing investors 5 minutes to react to news
Security analysis and enhancement of one-way hash based low-cost authentication protocol (OHLCAP)

Choi et al. recently proposed an efficient RFID authentication protocol for a ubiquitous computing environment, OHLCAP(One-Way Hash based Low-Cost Authentication Protocol). However, this paper reveals that the protocol has several security weaknesses :\ud
1) traceability based on the leakage of counter information,\ud
2) vulnerability to an impersonation attack by maliciously updating a random number, and\ud
3) traceability based on a physically-attacked tag. \ud
Finally, a security enhanced group-based authentication protocol is presented
New Formulae for Efficient Elliptic Curve Arithmetic

This paper is on efficient implementation techniques of Elliptic Curve Cryptography. In particular, we improve timings for Jacobi-quartic (3M+4S) and Hessian (7M+1S or 3M+6S) doubling operations. We provide a faster mixed-addition (7M+3S+1d) on modified Jacobi-quartic coordinates. We introduce tripling formulae for Jacobi-quartic (4M+11S+2d), Jacobi-intersection (4M+10S+5d or 7M+7S+3d), Edwards (9M+4S) and Hessian (8M+6S+1d) forms. We show that Hessian tripling costs 6M+4C+1d for Hessian curves defined over a field of characteristic 3. We discuss an alternative way of choosing the base point in successive squaring based scalar multiplication algorithms. Using this technique, we improve the latest mixed-addition formulae for Jacobi-intersection (10M+2S+1d), Hessian (5M+6S) and Edwards (9M+1S+ 1d+4a) forms. We discuss the significance of these optimizations for elliptic curve cryptography
Ontology for semantic integration in a cognitive surveillance system

Presentado al 2nd International Conference on Semantic and Digital Media Technologies (SAMT-2007) celebrado en Genova (Italia) del 5 al 7 de diciembre.The increasing interest in Cognitive Vision Systems (CVS) motivates the apparition of ad-hoc stages designed for the integration of multiple kinds of knowledge. This paper proposes a novel ontology to restrict and integrate high-level semantics for Human Sequence Evaluation (HSE), which targets multilingual capabilities and multipurpose end-user interfaces. The main contributions of this paper are the conception of a neutral semantic layer, which allows to link vision and linguistic domains; and the use of situations instead of verbs as basic elements for an ontological categorization of occurrences. In our approach, the domain has been restricted to outdoor surveilled scenarios, involving interactions among pedestrians, static objects, and vehicular traffic.Peer Reviewe
On the selection of MPEG-7 visual descriptors and their level of detail for nature disaster video sequences classification

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-77051-0_6Proceedings of Second International Conference on Semantic and Digital Media Technologies, SAMT 2007, Genoa, Italy, December 5-7, 2007.In this paper, we present a study on the discrimination capabilities of colour, texture and shape MPEG-7 visual descriptors, within the context of video sequences. The target is to facilitate the recognition of certain visual cues which would then allow the classification of natural disaster-related concepts. Low-level visual features are extracted using the MPEG-7 “eXperimentation Module” (XM). The extraction times associated to the levels of detail of the descriptors are measured. The pattern sets obtained as combination of significant levels of detail of different descriptors are the input to a Support Vector Machine (SVM), resulting on the classification accuracies. Preliminary results indicate that this approach could be useful for the implementation of real-time spatial regions classifiers.The work presented in this paper was partially supported by the European
Commision under contractFP6-027685 MESH, and by the Spanish Government under project TIN2004-
07860-C02 (MEDUSA) and by the Comunidad de Madrid under project S-0505/ TIC-0223 (ProMultiDis-
CM). Evaggelos Spyrou is funded by PENED 2003 – Project Ontomedia 03ED475
Searching for Ground Truth: a stepping stone in automating genre classification

This paper examines genre classification of documents and
its role in enabling the effective automated management of digital documents by digital libraries and other repositories. We have previously presented genre classification as a valuable step toward achieving automated extraction of descriptive metadata for digital material. Here, we present results from experiments using human labellers, conducted to assist in genre characterisation and the prediction of obstacles which need to be overcome by an automated system, and to contribute to the process of creating a solid testbed corpus for extending automated genre classification and testing metadata extraction tools across genres. We also describe the performance of two classifiers based on image and stylistic modeling features in labelling the data resulting from the agreement of three human labellers across fifteen genre classes.