pinecone/core-2020-05-10-deduplication huggingface dataset:
Web publishing: an extreme, agile experience

The proponents of agile methodologies suggest that many of the inhibitors to system development methodology adoption have largely been addressed in the underlying principles of agile methods. This paper reports the experience of a small team developing Web publishing software tools for use in building Web sites for online delivery of tertiary education study materials. These early adopters successfully used eXtreme Programming (XP) practices for this tool development exercise. Almost all XP practices were adopted, although some were adhered to more rigorously than others and some proved to be more successful than others. Continued use of XP and communication of its\ud
benefits to others has been a consequential focus for the developers
Extremal behavior of stochastic volatility models

Empirical volatility changes in time and exhibits tails, which are heavier than normal. Moreover, empirical volatility has - sometimes quite substantial - upwards jumps and clusters on high levels. We investigate classical and non-classical stochastic volatility models with respect to their extreme behavior. We show that classical stochastic volatility models driven by Brownian motion can model heavy tails, but obviously they are not able to model volatility jumps. Such phenomena can be modelled by Levy driven volatility processes as, for instance, by Levy driven Ornstein-Uhlenbeck models. They can capture heavy tails and volatility jumps. Also volatility clusters can be found in such models, provided the driving Levy process has regularly varying tails. This results then in a volatility model with similarly heavy tails. As the last class of stochastic volatility models, we investigate a continuous time GARCH(1,1) model. Driven by an arbitrary Levy process it exhibits regularly varying tails, volatility upwards jumps and clusters on high levels.
Agent-oriented information systems development using open and the agent factory

Information systems development (ISD) requires the underpinning of a high quality methodology (which includes elements to describe both the process of development and the work productswhich are the consumables used and produced by the process). However, each ISD project is different and the best-fit methodology is also consequently different. This means that a one-size-fits-all methodology will only rarely give ideal results (Cockburn, 2000), when the tenets of the methodology designer coincidentally coincide with those of the particular project
Shape Gradient for Image and Video Segmentation

International audienceIn this chapter, we propose to concentrate on the research of an optimal domain with regards to a global criterion including region andboundary functionals. A local shape minimizer is obtained through the evolution of a deformable domain in the direction of the shape gradient. Shape derivation tools, coming from shape optimization theory, allow us to easily differentiate region and boundary functionals. We more particularly focus on region functionals involving region-dependent features that are globally attached to the region. A general framework is proposed and illustrated by many examples involving functions of parametric or non parametric probability density functions (pdfs) of image features. Among these functions, we notably study the minimization of information measures such as the entropy for the segmentation of homogeneous regions or the minimization of the distance between pdfs for tracking or matching regions of interest
Photon-induced entanglement of distant mesoscopic SQUID rings

An experiment that involves two distant mesoscopic SQUID rings is studied.
The superconducting rings are irradiated with correlated photons, which are
produced by a single microwave source. Classically correlated (separable) and
quantum mechanically correlated (entangled) microwaves are considered, and
their effect on the Josephson currents is quantified. It is shown that the
currents tunnelling through the Josephson junctions in the distant rings, are
correlated.Comment: 9 pages, 3 figures; Kluwer Academic Proceedings; presented in IV
  international workshop on "Macroscopic Quantum Coherence and Computing"
  (Napoli, Italy, 2004
Practical Evaluation of a Network Mobility Solution

IFIP International Workshop on Networked Applications, Colmenarejo, Madrid/Spain, 6–8 July, 2005As the demand of ubiquitous Internet access and the current trend of all-IP communications keep growing, the necessity of a protocol that provides mobility management increases. The IETF has specified protocols to provide mobility support to individual nodes and networks. The Network Mobility (NEMO) Basic Support protocol is designed for providing mobility at IP level to complete networks, allowing a Mobile Network to change its point of attachment to the Internet, while maintaining ongoing sessions of the nodes of the network. All the mobility management is done by the mobile router whilst the nodes of the network are not even aware of the mobility.
The main aim of this article is evaluating the performance of the NEMO Basic Support protocol by using our implementation. We also discuss the design of an implementation of the NEMO Basic Support protocol.Publicad
An API for IPv6 Multihoming

IFIP International Workshop on Networked Applications, Colmenarejo, Madrid/Spain, 6?8 July, 2005This paper proposes an API for Multihoming in IPv6. This API is based on the Hash Based Addresses and Cryptographically Generated Addresses approaches, which are being developed by the IETF multi6 Working Group. The support of Multihoming implies several actions such as failure detection procedures, reachability tests, re-homing procedures and exchange of locators. Applications can benefit  from transparent access to Multihoming services only if per host Multihoming parameters are defined. However, more benefits could be obtained by applications if they will be able to configure these parameters. The proposed  Multihoming API provides different functions to applications which can modify some parameters and invoke some functions related with the Multihoming Layer.Publicad
Capacity evaluation of an indoor smart antenna system at 60 GHz

In this paper, a study for indoor channel modeling is presented for the millimeter frequency band, by using various configurations of multiple element antenna systems. A multi-ray model is proposed and verified through simulation process for capacity prediction of a high data rate wireless system. The proposed model utilizes the geometric characteristics of the environment, the angle of arrival and angle of departure of each one of the propagation paths, the antenna elements and their spacing. The results showed that the system capacity increases significantly if two or four elements are used at both terminal antennas instead of the basic SISO configuration. In order to accomplish major improvement in the data rates, a MIMO system at 60 GHz should operate within a range of 10 to 20 m in an indoor environment with the view of obtaining sufficient Signal to Noise Ratios. © 2006 International Federation for Information Processing
Ant seeker: An algorithm for enhanced web search

This paper proposes a web search algorithm, which aims to distinguish irrelevant information and to enhance the amount of the relevant information in respect to a user's query. The proposed algorithm is based on the Ant Colony Optimization algorithm (ACO), employing in parallel document similarity issues from the field of information retrieval. Ant Colony Optimization algorithms were inspired through the observation of ant colonies. In our approach, ants are used as agents through Internet, which are capable of collecting information, calculating the content similarity in each visited node and generating routing paths through the web. © 2006 International Federation for Information Processing
Chaotic encryption driven watermarking of human video objects based on Hu moments

A novel human video object watermarking scheme is proposed in this paper, providing copyright protection of semantic content. The proposed method focuses on the existence of face and body regions within an initial image, however other cases can also be addressed. Initially detection of human video objects is achieved using two adaptive 2-D Gaussian models, one for skin color distribution modelling and the other for body localization modelling. A watermark is then designed using invariant Hu moments of each human video object, and the watermark insertion procedure is driven by an iterative encryption module based on chaotic functions. Performance of the proposed object based secure watermarking system is tested under various signal distortions and known cryptanalytic attacks. © 2006 International Federation for Information Processing
Computer aided diagnosis of CT focal liver lesions based on texture features, feature selection and ensembles of classifiers

A computer aided diagnosis system aiming to classify liver tissue from computed tomography images is presented. For each region of interest five distinct sets of texture features were extracted. Two different ensembles of classifiers were constructed and compared. The first one consists of five Neural Networks (NNs), each using as input either one of the computed texture feature sets or its reduced version after feature selection. The second ensemble of classifiers was generated by combining five different type of primary classifiers, two NNs, and three k-nearest neighbor classifiers. The primary classifiers of the second ensemble used identical input vectors, which resulted from the combination of the five texture feature sets, either directly or after proper feature selection. The decision of each ensemble of classifiers was extracted by applying voting schemes. © 2006 International Federation for Information Processing
Stock market as a dynamic game with continuum of players

This paper contains a game-theoretic model describing the
behaviour of investors at a stock exchange.
The model presented is developed to reect the actual market microstructure.
The players constitute a non-uniform continuum, differing, among others, by the planning horizon, the external ow of money which can be invested, formation of expectations about future prices, which, briey, divides the investors
into the following groups: fundamental analysts, chartist, users of various econometric models, users of Capital Asset Pricing Model, and players observing a random exogenous signal.
Prices are determined by orders and the equilibrating mechanism of the stock exchange. The mechanism presented is the actual single-price auction system used, among others, at Warsaw Stock Exchange.
One of the main issues are self-verifying beliefs.
Results of numerical simulations of stock exchange based on the model are also included.
Uniformizing the Stacks of Abelian Sheaves

Elliptic sheaves (which are related to Drinfeld modules) were introduced by
Drinfeld and further studied by Laumon--Rapoport--Stuhler and others. They can
be viewed as function field analogues of elliptic curves and hence are objects
"of dimension 1". Their higher dimensional generalisations are called abelian
sheaves. In the analogy between function fields and number fields, abelian
sheaves are counterparts of abelian varieties. In this article we study the
moduli spaces of abelian sheaves and prove that they are algebraic stacks. We
further transfer results of Cerednik--Drinfeld and Rapoport--Zink on the
uniformization of Shimura varieties to the setting of abelian sheaves. Actually
the analogy of the Cerednik--Drinfeld uniformization is nothing but the
uniformization of the moduli schemes of Drinfeld modules by the Drinfeld upper
half space. Our results generalise this uniformization. The proof closely
follows the ideas of Rapoport--Zink. In particular, analogies of $p$-divisible
groups play an important role. As a crucial intermediate step we prove that in
a family of abelian sheaves with good reduction at infinity, the set of points
where the abelian sheaf is uniformizable in the sense of Anderson, is formally
closed.Comment: Final version, appears in "Number Fields and Function Fields - Two
  Parallel Worlds", Papers from the 4th Conference held on Texel Island, April
  2004, edited by G. van der Geer, B. Moonen, R. Schoo
Hilbert's 'World Equations' and His Vision of a Unified Science

In summer 1923, a year after his lectures on the `New Foundation of
Mathematics' and half a year before the republication of his two notes on the
`Foundations of Physics,' Hilbert delivered a trilogy of lectures in Hamburg.
In these lectures, Hilbert expounds in an unusually explicit manner his
epistemological perspective on science as a subdiscipline of an all embracing
science of mathematics. The starting point of Hilbert's considerations is the
claim that the class of gravitational and electromagnetic field equations
implied by his original variational formulation of 1915 provides valid
candidate `world equations,' even in view of attempts at unified field theories
\'a la Weyl and Eddington based on the concept of the affine connection. We
give a discussion of Hilbert's lectures and, in particular, examine his claim
that Einstein in his 1923 papers on affine unified field theory only arrived at
Hilbert's original 1915 theory. We also briefly comment on Hilbert's
philosophical viewpoints expressed in these lectures.Comment: 23 pages; to appear in Einstein Studie
Making Sense Through Participation

In this chapter we discuss the issue of social differences in relation to learning. In theories on co-operative learning or
 collaborative learning social differences are treated as characteristics of individual learners. The focus on learning as
 a social process is primarily elaborated in terms of interaction between pupils and the combined construction of knowledge. Sociocultural
 theory (Vygotsky, Lave & Wenger), however, understands ‘social’ not only in terms of knowledge/meaning being constructed in
 interaction with others, but also in terms of the cultural practices/activities informing these interaction processes. Learning
 can be understood as increasing participating in communities of practice. As social differences are an intrinsic part of the
 culture in which students are learning to participate, these are also an inherent aspect of learning processes in schools.
 Students learn to participate in practices in different ways, depending on their social position, and thus develop distinguished
 cultural identities. In this chapter we elaborate on this tenet, using examples from various empirical research projects on
 learning in secondary education. We not only show how social differences in the cultural practices that underpin learning
 influence what is learned by whom, but also explore the consequences of this perspective for the pedagogical space of the
 school
Electron Dephasing in Mesoscopic Metal Wires

The low-temperature behavior of the electron phase coherence time,
$\tau_{\phi}$, in mesoscopic metal wires has been a subject of controversy
recently. Whereas theory predicts that $\tau_{\phi}(T)$ in narrow wires should
increase as $T^{-2/3}$ as the temperature $T$ is lowered, many samples exhibit
a saturation of $\tau_{\phi}$ below about 1 K. We review here the experiments
we have performed recently to address this issue. In particular we emphasize
that in sufficiently pure Ag and Au samples we observe no saturation of
$\tau_{\phi}$ down to our base temperature of 40 mK. In addition, the measured
magnitude of $\tau_{\phi}$ is in excellent quantitative agreement with the
prediction of the perturbative theory of Altshuler, Aronov and Khmelnitskii. We
discuss possible explanations why saturation of $\tau_{\phi}$ is observed in
many other samples measured in our laboratory and elsewhere, and answer the
criticisms raised recently by Mohanty and Webb regarding our work.Comment: 14 pages, 3 figures; to appear in proceedings of conference
  "Fundamental Problems of Mesoscopic Physics", Granada, Spain, 6-11 September,
  200
Entanglement production in a chaotic quantum dot

It has recently been shown theoretically that elastic scattering in the Fermi
sea produces quantum mechanically entangled states. The mechanism is similar to
entanglement by a beam splitter in optics, but a key distinction is that the
electronic mechanism works even if the source is in local thermal equilibrium.
An experimental realization was proposed using tunneling between two edge
channels in a strong magnetic field. Here we investigate a low-magnetic field
alternative, using multiple scattering in a quantum dot. Two pairs of
single-channel point contacts define a pair of qubits. If the scattering is
chaotic, a universal statistical description of the entanglement production
(quantified by the concurrence) is possible. The mean concurrence turns out to
be almost independent on whether time-reversal symmetry is broken or not. We
show how the concurrence can be extracted from a Bell inequality using
low-frequency noise measurements, without requiring the tunneling assumption of
earlier work.Comment: 12 pages, 2 figures, Kluwer style file include
Creation and detection of mobile and non-local spin-entangled electrons

We present electron spin entanglers--devices creating mobile spin-entangled
electrons that are spatially separated--where the spin-entanglement in a
superconductor present in form of Cooper pairs and in a single quantum dot with
a spin singlet groundstate is transported to two spatially separated leads by
means of a correlated two-particle tunneling event. The unwanted process of
both electrons tunneling into the same lead is suppressed by strong Coulomb
blockade effects caused by quantum dots, Luttinger liquid effects or by
resistive outgoing leads. In this review we give a transparent description of
the different setups, including discussions of the feasibility of the
subsequent detection of spin-entanglement via charge noise measurements.
Finally, we show that quantum dots in the spin filter regime can be used to
perform Bell-type measurements that only require the measurement of zero
frequency charge noise correlators.Comment: 24 Kluwer pages, 7 figures - proceedings of the NATO/Euresco
  Conference (Granada Spain, 6-11 Sept. 2003); updated reference
Berezinskii-Kosterlitz-Thouless transition in Josephson junction arrays

The quantum XY model shows a Berezinskii-Kosterlitz-Thouless (BKT) transition
between a phase with quasi long-range order and a disordered one, like the
corresponding classical model. The effect of the quantum fluctuations is to
weaken the transition and eventually to destroy it. However, in this respect
the mechanism of disappearance of the transition is not yet clear. In this work
we address the problem of the quenching of the BKT in the quantum XY model in
the region of small temperature and high quantum coupling. In particular, we
study the phase diagram of a 2D Josephson junction array, that is one of the
best experimental realizations of a quantum XY model. A genuine BKT transition
is found up to a threshold value $g^\star$ of the quantum coupling, beyond
which no phase coherence is established. Slightly below $g^\star$ the phase
stiffness shows a reentrant behavior at lowest temperatures, driven by strong
nonlinear quantum fluctuations. Such a reentrance is removed if the dissipation
effect of shunt resistors is included.Comment: 14 pages, Kluwer style. Proceeding of the EURESCO conference
  "Fundamental Problems of Mesoscopic Physics", Sept. 2003, Granad
Transport in Luttinger Liquids

We compute the transport properties of one dimensional interacting electrons,
also known as a Luttinger liquid. We show that a renormalization group study
allows to obtain the temperature dependence of the conductivity in an
intermediate temperature range. In this range the conductivity has a power-law
like dependence in temperature. At low temperatures, the motion proceed by
tunnelling between localized configurations. We compute this tunnelling rate
using a bosonization representation and an instanton technique. We find a
conductivity $\sigma(T) \propto e^{-\beta^{1/2}}$, where $\beta$ is the
temperature. We compare this results with the standard variable range hopping
(VRH) formula.Comment: Proceedings of the EURESCO Conference "Fondamental Problems of
  Mesoscopic Physics", Granada, Spain (Sept. 2003), to be published by Kluwe
On the Electron-Electron Interactions in Two Dimensions

In this paper, we analyze several experiments that address the effects of
electron-electron interactions in 2D electron (hole) systems in the regime of
low carrier density. The interaction effects result in renormalization of the
effective spin susceptibility, effective mass, and g*-factor. We found a good
agreement among the data obtained for different 2D electron systems by several
experimental teams using different measuring techniques. We conclude that the
renormalization is not strongly affected by the material or sample-dependent
parameters such as the potential well width, disorder (the carrier mobility),
and the bare (band) mass. We demonstrate that the apparent disagreement between
the reported results on various 2D electron systems originates mainly from
different interpretations of similar "raw" data. Several important issues
should be taken into account in the data processing, among them the dependences
of the effective mass and spin susceptibility on the in-plane field, and the
temperature dependence of the Dingle temperature. The remaining disagreement
between the data for various 2D electron systems, on one hand, and the 2D hole
system in GaAs, on the other hand, may indicate more complex character of
electron-electron interactions in the latter system.Comment: Added refs; corrected typos. 19 pages, 7 figures. To be published in:
  Chapter 19, Proceedings of the EURESCO conference "Fundamental Problems of
  Mesoscopic Physics ", Granada, 200
Interactions in high-mobility 2D electron and hole systems

Electron-electron interactions mediated by impurities are studied in several
high-mobility two-dimensional (electron and hole) systems where the parameter
$k_BT\tau /\hbar $ changes from 0.1 to 10 ($\tau$ is the momentum relaxation
time). This range corresponds to the \textit{intermediate} and \textit
{ballistic} regimes where only a few impurities are involved in
electron-electron interactions. The interaction correction to the Drude
conductivity is detected in the temperature dependence of the resistance and in
the magnetoresistance in parallel and perpendicular magnetic fields. The
effects are analysed in terms of the recent theories of electron interactions
developed for the ballistic regime. It is shown that the character of the
fluctuation potential (short-range or long-range) is an important factor in the
manifestation of electron-electron interactions in high-mobility 2D systems.Comment: 22 pages, 11 figures; to appear in proceedings of conference
  "Fundamental Problems of Mesoscopic Physics", Granada, Spain, 6-11 September,
  200