pinecone/core-2020-05-10-deduplication huggingface dataset:
Wire-based tracking using mutual information

Presentado al 10th International Symposium on Advances in Robot Kinematics (ARK/2006) celebrado en Lyubljana (Eslovenia).Wire-based tracking devices are an affordable alternative to costly tracking devices. They consist of a fixed base and a platform, attached to the moving object, connected by six wires whose tension is maintained along the tracked trajectory. One important shortcoming of this kind of devices is that they are forced to operate in reduced workspaces so as to avoid singular configurations. Singularities can be eliminated by adding more wires but this causes more wire interferences, and a higher force exerted on the moving object by the measuring device itself. This paper shows how, by introducing a rotating base, the number of wires can be reduced to three, and singularities can be avoided by using an active sensing strategy. This also permits reducing wire interference problems and the pulling force exerted by the device. The proposed sensing strategy minimizes the uncertainty in the location of the platform. Candidate motions of the rotating base are compared selected automatically based on mutual information scores.This work was supported by projects: 'Design and implementation of efficient parallelizable algorithms with applications to robotics and proteomics' (J-00869), 'Planificador de trayectorias para sistemas robotizados de arquitectura arbitraria' (J-00930), 'Integration of robust perception, learning, and navigation systems in mobile robotics' (J-0929), 'Perception, action & cognition through learning of object-action complexes.' (4915).J. Andrade-Cetto completed this work as a Juan de la Cierva Post-doctoral Fellow of the Spanish Ministry of Education and Science under\ud
project TIC2003-09291 and was also supported in part by projects DPI 2004-05414, and the EU PACO-PLUS project FP6-2004-IST-4-27657. F. Thomas was partially supported by the Spanish Ministry of\ud
Education and Science, projects TIC2003-03396 and DPI 2004-07358, and the Catalan Research Commission, through the Robotics and Control\ud
Group.Peer Reviewe
Fluctuations near the deconfinement phase transition boundary

In this talk I discuss how a first order phase transition may proceed in
rapidly expanding partonic matter produced in a relativistic heavy-ion
collision. The resulting picture is that a strong collective flow of matter
will lead to the fragmentation of a metastable phase into droplets. If the
transition from quark-gluon plasma to hadron gas is of the first order, it will
manifest itself by strong nonstatistical fluctuations in observable hadron
distributions. I discuss shortly existing experimental data on the multiplicity
fluctuations.Comment: Invited talk at the International Conference "New trends in
  high-energy physics" (Crimea, September 10-17, 2005), 11 pages, 5 figure
Exercising self through working life: Learning, work and identity

This chapter discusses what motivates and directs individuals' lifelong learning. It proposes that individuals' sense of self shapes and is shaped by their participation and learning throughout working life through a quest to become themselves. In encouraging individuals to 'help themselves' in their learning throughout their working life, this learning is likely to be driven by personal intentions and their agency rather than the goals of others. Therefore, the agency and intentionality that directs that quest may not always coincide with the kinds of goals that government and employers want. Instead, helping oneself is likely to be directed by and towards their sense of self, which includes the negotiation of identity as they engage in work. It follows that in understanding the processes of learning and the remaking of work practice, a greater acknowledgement of individuals' sense of self needs acknowledging and to be accounted for in policies and practices associated with lifelong learning. Policy and policy-related initiatives might need to account for factors that motivate and engage individuals in the process of learning throughout working life and not assume that goals beyond the individual will be sufficient for mobilising that learning.Arts, Education & Law Group, School of Education and Professional StudiesFull Tex
Changing work, work practice: the consequences for vocational education

This chapter discusses the changing and emerging characteristics of work, work practice and work requirements, and their consequences for vocational education. Changing patterns in work and working life are proposed as comprising: (i) the kind of available; (ii) how individuals participate in work; (iii) what constitutes competence within that work, and (iv) those participating in work. The consequences for vocational education are systemic in terms of the kinds of occupations that need to be developed, variations in and complexity of work requirements, shifts in employer-employee relations, and the demographic shifts in those who will need to be supported by vocational education. The chapter elaborates these patterns of change to work and working life and discusses policy and curriculum practice associated with each. Overall, it argues that, the changes to work make it more demanding, and the frequency of change in work and how work is practised, demands careful, comprehensive and targeted preparation and on-going development. Moreover, with broader participation in the work force and longer working lives, the arrangement for this preparation and ongoing development will need to be targeted, differentiated and sustained.Arts, Education & Law Group, School of Education and Professional StudiesFull Tex
Vocational Learning: Contributions of Workplaces and Educational Institutions

This chapter identifies contributions to the learning of vocational practice from experiences in both educational institutions and workplaces. It proposes that each of these setting potentially provides particular contributions to learning vocational practice. When each set of contributions is usefully exercised and integrated they stand to purposefully support rich and robust vocational learning. Yet, this integration is not possible in all circumstances. Therefore, it is important to understand the strengths and weaknesses of the contributions from both kinds of settings, and how best their learning potential can be maximised and their weaknesses limited. This paper is structured to achieve these purposes. Consideration is given first to the kinds of knowledge required to be learnt for effective vocational practice. Next, the contributions to learning vocational practices from both workplace and educational settings are discussed through a consideration of the strengths and weaknesses of their respective contributions. Consideration is then given to how best to integrate the contributions of both environments to provide optimum learning experiences.Arts, Education & Law Group, School of Education and Professional StudiesFull Tex
Transforming Teachers’ Practice Through Action Learning

This chapter critically appraises the potential of action learning as a professional development strategy for teachers. Using the case of a professional development program which prepared vocational teachers to become industry consultants, the chapter examines the potential and the impediments of this approach to managing change in technical and vocational education. The chapter commences with a brief commentary on individual change or learning from cognitive and social constructivist and change theory perspectives. Next, the case study is described and findings from an evaluation of the program are discussed. Finally, some conclusions are drawn about how the action learning based approaches to educational change might be best enacted and evaluated.Arts, Education & Law Group, School of Education and Professional StudiesFull Tex
Astronomy, Astrophysics, and Space Physics in Greece

In the present document I review the current organizational structure of
Astronomy, Astrophysics and Space Physics in Greece. I briefly present the
institutions where professional astronomers are pursuing research, along with
some notes of their history, as well as the major astronomical facilities
currently available within Greece. I touch upon topics related to graduate
studies in Greece and present some statistics on the distribution of Greek
astronomers. Even though every attempt is made to substantiate all issues
mentioned, some of the views presented have inevitably a personal touch and
thus should be treated as such.Comment: Paper to be published in ``Organizations and Strategies in Astronomy
  -- Vol. 7, Ed. A. Heck, 2006, Springer, Dordrecht". Higher resolution version
  available at http://www.physics.uoc.gr/~vassilis/papers/AstroInGreece.pd
Wind-Blown Bubbles around Evolved Stars

Most stars will experience episodes of substantial mass loss at some point in their lives. For very massive stars, mass loss dominates their evolution, although the mass loss rates are not known exactly, particularly once the star has left the main sequence. Direct observations of the stellar winds of massive stars can give information on the current mass-loss rates, while studies of the ring nebulae and HI shells that surround many Wolf-Rayet (WR) and luminous blue variable (LBV) stars provide information on the previous mass-loss history. The evolution of the most massive stars, (M > 25 solar masses), essentially follows the sequence O star to LBV or red supergiant (RSG) to WR star to supernova. For stars of mass less than 25 solar masses there is no final WR stage. During the main sequence and WR stages, the mass loss takes the form of highly supersonic stellar winds, which blow bubbles in the interstellar and circumstellar medium. In this way, the mechanical luminosity of the stellar wind is converted into kinetic energy of the swept-up ambient material, which is important for the dynamics of the interstellar medium. In this review article, analytic and numerical models are used to describe the hydrodynamics and energetics of wind-blown bubbles. A brief review of observations of bubbles is given, and the degree to which theory is supported by observations is discussed
Spectropolarimetry and the study of circumstellar disks

Circumstellar disks play an important role in many stages of the evolution of stars. However, it is only possible to directly image circumstellar disks for a few of the nearest stars. For massive stars, the situation is even more difficult, as they are on average further away than the more numerous low mass stars. Here, we discuss spectropolarimetry which is a technique that can reveal the presence of disks on spatial scales of order stellar radii. It is therefore extremely useful in studying disks around young stars, while the method has prospects for quantitative modelling. In this review we will discuss the status on the study of (accretion) disks around intermediate- to high mass pre-main sequence stars and will concentrate on the linear spectropolarimetry aspect. We wil make a brief excursion to observations of massive evolved stars where spectropolarimetry has revealed the clumpy structure of stellar winds, and conclude with a brief outlook
Collapse of the Primordial Gas Clouds in the Presence of UV Radiation Field

Our goal is to study the effects of the UV radiation from the first stars, quasars and hypothetical Super Heavy Dark Matter (SHDM) particle decays on the formation of primordial bound objects in the Universe. We trace the evolution of a spherically symmetric density perturbation in the Lambda Cold Dark Matter and MOND model, solving the frequency-dependent radiative transfer equation, non-equilibrium chemistry, and one-dimensional gas hydrodynamics. We concentrate on the destruction and formation processes of the $H_{2}$ molecule, which is the main coolant in the primordial objects
Understanding Galaxy Formation and Evolution

The old dream of integrating into one the study of micro and macrocosmos is now a reality. Cosmology, astrophysics, and particle physics intersect in a scenario (but still not a theory) of cosmic structure formation and evolution called Lambda Cold Dark Matter (LCDM) model. This scenario emerged mainly to explain the origin of galaxies. In these lecture notes, I first present a review of the main galaxy properties, highlighting the questions that any theory of galaxy formation should explain. Then, the cosmological framework and the main aspects of primordial perturbation generation and evolution are pedagogically detached. Next, I focus on the ``dark side'' of galaxy formation, presenting a review on LCDM halo assembling and properties, and on the main candidates for non-baryonic dark matter. It is shown how the nature of elemental particles can influence on the features of galaxies and their systems. Finally, the complex processes of baryon dissipation inside the non-linearly evolving CDM halos, formation of disks and spheroids, and transformation of gas into stars are briefly described, remarking on the possibility of a few driving factors and parameters able to explain the main body of galaxy properties. A summary and a discussion of some of the issues and open problems of the LCDM paradigm are given in the final part of these notes
Ultra-high energy cosmic rays: from GeV to ZeV

Cosmic ray (CR) particles arrive at the top of the Earth's atmosphere at a rate of around 1000 per square meter per second. They are mostly ionized nuclei - about 90% protons, 9% alpha particles traces of heavier nuclei and approximately 1% electrons. CRs are characterized by their high energies: most cosmic rays are relativistic, having kinetic energies comparable to or somewhat greater than their rest masses. A very few of them have ultra-relativistic energies extending beyond 100 EeV (tens of joules). In this series of lectures, delivered at the 2005 Mexican School of Astrophysics, an overview of the main experimental characteristics of the CR flux and their astrophysical significance is given. Particular emphasis is given to the upper end of the CR energy spectrum. Unfortunately, due to space limitations, only a fraction of the original content of the lectures is included in the present manuscript. In particular, the production mechanisms are not included and the fundamental topic of anisotropies is only dealt with in a very superficial way
Image binarisation using the extended Kalman filter

This work has been mainly supported by Grant 73604 of the University of Malta.Form design is frequently carried out through paper sketches of the designer’s mental model of an object. To improve the time it takes from solution concept to production it would therefore be beneficial if paperbased sketches can be automatically interpreted for importation into three-dimensional geometric computer aided design (CAD) systems. This however requires image pre-processing before initiating the automated interpretation of the drawing. This paper proposes a novel application of the Extended Kalman Filter to guide the binarisation process, thus achieving suitable and automatic classification between image foreground and background.peer-reviewe
Zero-Bias Conductance Through Side-Coupled Double Quantum Dots

Low temperature zero-bias conductance through two side-coupled quantum dots
is investigated using Wilson's numerical renormalization group technique. A
low-temperature phase diagram is computed. Near the particle-hole symmetric
point localized electrons form a spin-singlet associated with weak conductance.
For weak inter-dot coupling we find enhanced conductance due to the two-stage
Kondo effect when two electrons occupy quantum dots. When quantum dots are
populated with a single electron, the system enters Kondo regime with enhanced
conductance. Analytical expressions for the width of the Kondo regime and the
Kondo temperature in this regime are given.Comment: to be published in the Proceedings of the NATO Advanced Research
  Workshop on "Electron Correlations in New Materials and Nanosystems" held in
  Yalta, Ukraine, 19 - 23 September 2005 (NATO Science Series II, Springer
  2006
Electron-electron interaction in carbon nanostructures

The electron-electron interaction in carbon nanostructures was studied. A new
method which allows to determine the electron-electron interaction constant
$\lambda_c$ from the analysis of quantum correction to the magnetic
susceptibility and the magnetoresistance was developed. Three types of carbon
materials: arc-produced multiwalled carbon nanotubes (arc-MWNTs), CVD-produced
catalytic multiwalled carbon nanotubes (c-MWNTs) and pyrolytic carbon were used
for investigation. We found that $\lambda_c$=0.2 for arc-MWNTs (before and
after bromination treatment); $\lambda_c$ = 0.1 for pyrolytic graphite;
$\lambda_c >$ 0 for c-MWNTs. We conclude that the curvature of graphene layers
in carbon nanostructures leads to the increase of the electron-electron
interaction constant $\lambda_c$.Comment: 12 pages, 18 figures, to be published in the Proceedings of the NATO
  Advanced Research Workshop on Electron Correlation in New Materials and
  Nanosystems, NATO Science Series II, Springer, 200
Improving cereal productivity and farmers’ income using a strategic application of fertilizers in West Africa

In the past two years, ICRISAT, in collaboration with other International Agricultural Research Centres, National Agricultural Research and Extension Systems, has been evaluating and promoting point or hill application of fertilizer along with “Warrantage” in three West African countries, namely, Burkina Faso, Mali and Niger. The hill application of fertilizers consists of applying small doses of fertilizer in the planting hills of millet and sorghum. The combination of strategic hill application of fertilizer with complementary institutional and market linkages, through an inventory credit system (known as “Warrantage”) offers a good opportunity to improve crop productivity and farmers’ incomes. Results from the two year on-farm trials showed that, on average, in all the three countries, grain yields of millet and sorghum were greater by 44 to 120% while incomes of farmers increased by 52 to 134% when using hill application of fertilizer than with the earlier recommended fertilizer broadcasting methods and farmers’ practice. Substantial net profits were obtained by farmers using “Warrantage”. Farmers’ access to credit and inputs was improved substantially through the “Warrantage” system. The technology has reached up to 12650 farm households in the three countries and efforts are in progress to further scale-up and out the technology to wider geographical area
Policies, institutions and market development to accelerate technological change in the semiarid zones of Sub-Saharan Africa

Agriculture in the African dry lands is constrained by geographical and economic isolation due to limited market access which affect adoption of new technology. International subsidies that flood developing-world markets with cheap food, national policies that tax the agricultural sector to benefit urban interests, and neglect of rural infrastructure discourage agricultural intensification. Increased market demand for staples and for higher-value products produced more efficiently will ensure that dryland farmers realize an economic gain from adopting more intensive practices. The interdependence of these key factors requires an integrated management of water soil fertility and improved crop varieties research focused on the poor, particularly women and children to ensure that they are equipped to capture most of the benefits of these changes. Low-value but essential food security crops need public sector assistance until their intensification becomes attractive to the private sector. Drought and market risks determine farmers’ decision-making in the drylands; yet it is too often assumed that new technology increases risk. Some technologies, policies and institutions can reduce risk..
Study of some optimal XFEM type methods

The XFEM method in fracture mechanics is revisited. A first improvement is considered using an enlarged fixed enrichment subdomain aroud the crack tip and a bonding condition for the corresponding degree of freedom. An efficient numerical integration rule is introduced for the nonsmooth enrichment functions. The lack of accuracy due to the transition layer between the enrichment aera and the rest of the domain leads to consider a pointwise matching condition at the boundary of the subdomain. An optimal numerical rate of convergence is then obtained using such a nonconformal method
Modelling Trust In Wireless Sensor Networks from the Sensor Reliability Prospective

This paper surveys the state of the art trust-based systems in Wireless Sensor Networks (WSN); it highlights the difference between Mobile ad hoc networks (MANET) and WSN and based on this observed difference (monitoring events and reporting data) a new trust model is introduced, which takes sensor reliability as a component of trust. A new definition of trust is created based on the newly introduced component of trust (sensor data) and an extension of node misbehaviour classification is also presented based on this new component of trust
Viruses in extreme environments

Article également publié dans : Reviews in environmental science and bio-technology 6, 1-3 (2007) 17-31 - http://hal.univ-brest.fr/hal-00563692/fr/The tolerance limits of extremophiles in term of temperature, pH, salinity, desiccation, hydrostatic pressure, radiation, anaerobiosis far exceed what can support non extremophilic organisms. Like all other organisms, extremophiles serve as hosts for viral replication. Many lines of evidence suggest that viruses could no more be regarded as simple infectious “fragments of life” but on the contrary as one of the major components of the biosphere. The exploration of niches with seemingly harsh life conditions as hypersaline and soda lakes, Sahara desert, polar environments or hot acid springs and deep sea hydrothermal vents, permitted to track successfully the presence of viruses. Substantial populations of double-stranded DNA virus that can reach 109 particles per milliliter were recorded. All these viral communities, with genome size ranging from 14 to 80 kb, seem to be genetically distinct, suggesting specific niche adaptation. Nevertheless, at this stage of the knowledge, very little is known of their origin, activity, or importance to the in situ microbial dynamics. The continuous attempts to isolate and to study viruses that thrive in extreme environments will be needed to address such questions. However, this topic appears to open a new window on an unexplored part of the viral world
Spacetime: Arena or Reality?

For small values of the mass (in relation to the angular momentum and
electric charge), the Kerr-Newman (KN) solution of Einstein equation reduces to
a naked singularity of circular shape. By considering the Hawking and Ellis
extended interpretation of the KN spacetime, as well as Wheeler's idea of
"charge without charge", the non-trivial topological structure of the extended
KN spatial section is found to represent gravitational states with
half-integral angular momentum. As a consequence, it can be consistently
interpreted as a model for the electron-positron system, in which the concepts
of mass, charge and spin emerge from the spacetime geometry. According to this
model, therefore, instead of a simple arena, spacetime must have a concrete
existence, being responsible -- through its highly non-trivial topological
structures -- for the building blocks of (at least some of) the existing matter
in the universe.Comment: Chapter in the book "Relativity and the Dimensionality of the World",
  Springer series "Fundamental Theories of Physics", Vol. 153 (2007). Volume
  Editor: Vesselin Petko