pinecone/core-2020-05-10-deduplication huggingface dataset:
Non-local means variants for denoising of diffusion-weighted and diffusion tensor MRI.

International audienceDiffusion tensor imaging (DT-MRI) is very sensitive to corrupting noise due to the non linear relationship between the diffusion-weighted image intensities (DW-MRI) and the resulting diffusion tensor. Denoising is a crucial step to increase the quality of the estimated tensor field. This enhanced quality allows for a better quantification and a better image interpretation. The methods proposed in this paper are based on the Non-Local (NL) means algorithm. This approach uses the natural redundancy of information in images to remove the noise. We introduce three variations of the NL-means algorithms adapted to DW-MRI and to DT-MRI. Experiments were carried out on a set of 12 diffusion-weighted images (DW-MRI) of the same subject. The results show that the intensity based NL-means approaches give better results in the context of DT-MRI than other classical denoising methods, such as Gaussian Smoothing, Anisotropic Diffusion and Total Variation
Stellar Velocity Distribution in Galactic Disks

We present numerical studies of the properties of the stellar velocity
distribution in galactic disks which have developed a saturated, two-armed
spiral structure. In previous papers we used the Boltzmann moment equations
(BME) up to second order for our studies of the velocity structure in
self-gravitating stellar disks. A key assumption of our BME approach is the
zero-heat flux approximation, i.e. the neglection of third order velocity
terms. We tested this assumption by performing test particle simulations for
stars in a disk galaxy subject to a rotating spiral perturbation. As a result
we corroborated qualitatively the complex velocity structure found in the BME
approach. It turned out that an equilibrium configuration in velocity space is
only slowly established on a typical timescale of 5 Gyrs or more. Since many
dynamical processes in galaxies (like the growth of spirals or bars)act on
shorter timescales, pure equilibrium models might not be fully appropriate for
a detailed comparison with observations like the local Galactic velocity
distribution. Third order velocity moments were typically small and
uncorrelated over almost all of the disk with the exception of the 4:1
resonance region (UHR). Near the UHR (normalized) fourth and fifth order
velocity moments are still of the same order as the second and third order
terms. Thus, at the UHR higher order terms are not negligible.Comment: 8 pages, 3 figures, to appear in the Proceedings of "Chaos in
  Astronomy", Athens, G. Contopoulos & P.A. Patsis (eds.
Cosmic Order out of Primordial Chaos: a tribute to Nikos Voglis

Nikos Voglis had many astronomical interests, among them was the question of
the origin of galactic angular momentum. In this short tribute we review how
this subject has changed since the 1970's and how it has now become evident
that gravitational tidal forces have not only caused galaxies to rotate, but
have also acted to shape the very cosmic structure in which those galaxies are
found. We present recent evidence for this based on data analysis techniques
that provide objective catalogues of clusters, filaments and voids.Comment: 16 pp., 6 figures, invited review "Chaos in Astronomy 2007", ed. P.
  Patsis, G. Contopoulos, Springer-Verlag. For high-res version see
  http://www.astro.rug.nl/~weygaert/tim1publication/joneswey.nikos-2007.pd
Search engines and expertise about global issues: well-defined landscape or undomesticated wilderness?

This is a book chapter. The original publication is available at www.springerlink.com.This chapter investigates the ‘winner-takes-all’ hypothesis in relation\ud
to how academic researchers access online sources and resources. Some have\ud
argued that the Web provides access to a wider range of sources of information than\ud
offline resources. Others, such as Hindman et al. (2003), have shown that access to\ud
online resources is highly concentrated, particularly because of how Internet search\ud
engines are designed. With researchers increasingly using the Web and Internet\ud
search engines to disseminate and locate information and expertise, the question of\ud
whether the use of online resources enhances or diminishes the range of available\ud
sources of expertise is bound to become more pressing. To address this question\ud
four globally relevant knowledge domains were investigated using large-scale\ud
link analysis and a series of semi-structured interviews with UK-based academic\ud
researchers.\ud
We found there to be no uniform ‘winner-takes-all’ effect in the use of online\ud
resources. Instead, there were different types of information gatekeepers for the\ud
four domains we examined and for the types of resources and sources that are\ud
sought. Particular characteristics of a knowledge domain’s information environment\ud
appear to determine whether Google and other Internet search engines function\ud
as a facilitator in accessing expertise or as an influential gatekeeper
A Formal Foundation for Knowledge Integration of Defficent Information in the Semantic Web

Maintenance of logical robustness in Information Integration represents a major challenge in the envisioned Semantic Web. In this framework, it is previsible unprecise information (with respect to an ontology) is retrieved from some resources. The sound integration of such information is crucial to achieve logical soundness. We present a data-driven approach to classify that knowledge by means of the cognitive entropy of the possible robust ontology extensions and data.Ministerio de Educación y Ciencia TIN2004-0388
Metaheuristic approaches for optimal broadcasting design in metropolitan MANETs

11th International Conference on Computer Aided Systems Theory. Las Palmas de Gran Canaria, Spain, February 12-16, 2007Mobile Ad-hoc Networks (MANETs) are composed of a set of communicating devices which are able to spontaneously interconnect without any pre-existing infrastructure. In such scenario, broadcasting becomes an operation of tremendous importance for the own existence and operation of the network. Optimizing a broadcasting strategy in MANETs is a multiobjective problem accounting for three goals: reaching as many stations as possible, minimizing the network utilization, and reducing the duration of the operation itself. This research, which has been developed within the OPLINK project (http://oplink.lcc.uma.es), faces a wide study about this problem in metropolitan MANETs with up to seven different advanced multiobjective metaheuristics. They all compute Pareto fronts of solutions which empower a human designer with the ability of choosing the preferred configuration for the network. The quality of these fronts is evaluated by using the hypervolume metric. The obtained results show that the SPEA2 algorithm is the most accurate metaheuristic for solving the broadcasting problem.Publicad
A quality of service assessment technique for large-scale management of multimedia flows

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-540-75869-3_15Proceedings of 10th IFIP/IEEE International Conference on Management of Multimedia and Mobile Networks and Services, MMNS 2007, San José, USA, October 31 - November 2, 2007This paper presents the concept and preliminary experiments of a system for assessing on the Quality of Service of multimedia flows. The goal is to devise a mechanism that allows a service provider to take action whenever poor quality of service is detected in the delivery of multimedia flows. Such procedure is fully automatic since it is based on a goodness-of-fit test between source and destination packet interarrival histograms. If the null hypothesis of the test is accepted the flow is marked as in good standing, otherwise it is marked as anomalous and the network management system should take action in response. The proposed technique is analyzed in terms of hardware complexity and bandwidth consumption. The results show this technique is feasible and easily deployable at a minimum hardware and bandwidth expense.The authors would like to acknowledge the support of the Comunidad Autónoma de
Madrid to this work, under project e-Magerit (S-0505/TIC/000251)
A Generic Module System forWeb Rule Languages:
Divide and Rule

An essential feature in practically usable programming languages is
the ability to encapsulate functionality in reusable modules. Modules make large
scale projects tractable by humans. For Web and Semantic Web programming,
many rule-based languages, e.g. XSLT, CSS, Xcerpt, SWRL, SPARQL, and RIF
Core, have evolved or are currently evolving. Rules are easy to comprehend
and specify, even for non-technical users, e.g. business managers, hence easing
the contributions to the Web. Unfortunately, those contributions are arguably
doomed to exist in isolation as most rule languages are conceived without modularity,
hence without an easy mechanism for integration and reuse. In this paper
a generic module system applicable to many rule languages is presented. We
demonstrate and apply our generic module system to a Datalog-like rule language,
close in spirit to RIF Core. The language is gently introduced along the
EU-Rent use case. Using the Reuseware Composition Framework, the module
system for a concrete language can be achieved almost for free, if it adheres to
the formal notions introduced in this paper.
Cursive Character Segmentation Using Neural Network Techniques

The segmentation of cursive and mixed scripts persists to be a difficult problem in the area of handwriting recognition. This research details advances for segmenting characters in off-line cursive script. Specifically, a heuristic algorithm and a neural network-based technique, which uses a structural feature vector representation, are proposed and combined for identifying incorrect segmentation points. Following the location of appropriate anchorage points, a character extraction technique, using segmentation paths, is employed to complete the segmentation process. Results are presented for neural-based heuristic segmentation, segmentation point validation, character recognition, segmentation path detection and overall segmentation accuracy.Griffith Sciences, School of Information and Communication TechnologyFull Tex
Efficient Computation of Throughput Values of Context-Free Languages

International audienceWe give the first deterministic polynomial time algorithm that computes the throughput value of a given context-free language L. The language is given by a grammar G of size n, together with a weight function assigning a positive weight to each symbol. The weight of a word w ∈ L is defined as the sum of weights of its symbols (with multiplicities), and the mean weight is the weight of w divided by length of w. The throughput of L, denoted by throughput(L), is the smallest real number t, such that the mean value of each word of L is not smaller than t. Our approach, to compute throughput(L), consists of two phases. In the first one we convert the input grammar G to a grammar G′, generating a finite language L′, such that throughput(L)=throughput(L'). In the next phase we find a word of the smallest mean weight in a finite language L′. The size of G′ is polynomially related to the size of G. The problem is of practical importance in system-performance analysis, especially in the domain of network packet processing, where one of the important parameters is the "guaranteed throughput" of a system for on-line network packet processing
A Rule-based Adaption Model for Ontology-based Personalization

Various adaptive hypermedia systems have been proposed to alleviate information overload on the Web by personalising the delivery of information and resources to the user. These systems have however been afflicted with difficulties in the acquisition of an accurate user model, a limited degree of customization offered to the user as well as general lack of user control on and transparency of the systems’ adaptive behavior. In this chapter, we argue that the use of rules on top on ontologies can enable adaptive functionality that is transparent and controllable for users. To this end, we present ODAS, a domain ontology for adaptive hypermedia systems, and a model for the specification of ODAS-based adaptation rules. We demonstrate the use of this model by showing how it can be instantiated within a knowledge portal to arrive at rules that exploit ODAS semantics to perform meaningful personalization.
Applying Local Cooccurring Patterns for Object Detection from Aerial Images

Developing a spatial searching tool to enhance the search capabilities of large spatial repositories for Geographical Information System (GIS) update has attracted more and more attention. Typically, objects to be detected are represented by many local features or local parts. Testing images are processed by extracting local features which are then matched with the objectâs model image. Most existing work that uses local features assumes that each of the local features is independent to each other. However, in many cases, this is not true. In this paper, a method of applying the local cooccurring patterns to disclose the cooccurring relationships between local features for object detection is presented. Features including colour features and edge-based shape features of the interested object are collected. To reveal the cooccurring patterns among multiple local features, a colour cooccurrence histogram is constructed and used to search objects of interest from target images. The method is demonstrated in detecting swimming pools from aerial images. Our experimental results show the feasibility of using this method for effectively reducing the labour work in finding man-made objects of interest from aerial images
RELT: Visualizing Trees on Mobile Devices

The small screens on increasingly used mobile devices challenge the traditional visualization methods designed for desktops. This paper presents a method called Radial Edgeless Tree (RELT) for visualizing trees in a 2-dimensional space. It combines the existing connection tree drawing with the space-filling approach to achieve the efficient display of trees in a small geometrical area, such as the screen that are commonly used in mobile devices. We recursively calculate a set of non-overlapped polygonal nodes that are adjacent in the hierarchical manner. Thus, the display space is fully used for displaying nodes, while the hierarchical relationships among the nodes are presented by the adjacency (or boundary-sharing) of the nodes. It is different from the other traditional connection approaches that use a node-link diagram to present the parent-child relationships which waste the display space. The hierarchy spreads from north-west to south-east in a top-down manner which naturally follows the traditional way of human perception of hierarchies. We discuss the characteristics, advantages and limitations of this new technique and suggestions for future research
Empirical studies of open source evolution

Copyright @ 2008 Springer-VerlagThis chapter presents a sample of empirical studies of Open Source Software (OSS) evolution. According to these studies, the classical results from the studies of proprietary software evoltion, such as Lehman’s laws of software evolution, might need to be revised, if not fully, at least in part, to account for the OSS observations. The book chapter also summarises what appears to be the empirical\ud
status of each of Lehman’s laws with respect to OSS and highlights the threads to\ud
validity that frequently emerge in these empirical studies. The chapter also discusses\ud
related topics for further research
A novel information theory method for filter feature selection

In this paper, we propose a novel filter for feature selection. Such filter relies on the estimation of the mutual information between features and classes. We bypass the estimation of the probability density function with the aid of the entropic-graphs approximation of Rényi entropy, and the subsequent approximation of the Shannon one. The complexity of such bypassing process does not depend on the number of dimensions but on the number of patterns/samples, and thus the curse of dimensionality is circumvented. We show that it is then possible to outperform a greedy algorithm based on the maximal relevance and minimal redundancy criterion. We successfully test our method both in the contexts of image classification and microarray data classification.This research is funded by the project DPI2005-01280 from the Spanish Government
A Probabilistic Applied Pi-Calculus

International audienceWe propose an extension of the Applied Pi–calculus by introducing nondeterministic and probabilistic choice operators. The semantics of the resulting model, in which probability and nondeterminism are combined, is given by Segala's Probabilistic Automata driven by schedulers which resolve the nondeterministic choice among the probability distributions over target states. Notions of static and observational equivalence are given for the enriched calculus. In order to model the possible interaction of a process with its surrounding environment a labeled semantics is given together with a notion of weak bisimulation which is shown to coincide with the observational equivalence. Finally, we prove that results in the probabilistic framework are preserved in a purely nondeterministic setting
Complete Lattices and Up-to Techniques

24 p.International audienceWe propose a theory of up-to techniques for proofs by coinduction, in the setting of complete lattices. This theory improves over existing results by providing a way to compose arbitrarily complex techniques with standard techniques, expressed using a very simple and modular semi-commutation property. Complete lattices are enriched with monoid operations, so that we can recover standard results about labelled transitions systems and their associated behavioural equivalences at an abstract, "point-free'' level. Our theory gives for free a powerful method for validating up-to techniques. We use it to revisit up to contexts techniques, which are known to be difficult in the weak case: we show that it is sufficient to check basic conditions about each operator of the language, and then rely on an iteration technique to deduce general results for all contexts
CCS with Replication in the Chomsky Hierarchy: The Expressive Power of Divergence

International audienceA remarkable result in [4] shows that in spite of its being less expressive than CCS w.r.t. weak bisimilarity, CCS! (a CCS variant where infinite behavior is specified by using replication rather than recursion) is Turing powerful. This is done by encoding Random Access Machines (RAM) in CCS!. The encoding is said to be non-faithful because it may move from a state which can lead to termination into a divergent one which do not correspond to any configuration of the encoded RAM. I.e., the encoding is not termination preserving. In this paper we study the existence of faithful encodings into CCS! of models of computability strictly less expressive than Turing Machines. Namely, grammars of Types 1 (Context Sensitive Languages), 2 (Context Free Languages) and 3 (Regular Languages) in the Chomsky Hierarchy. We provide faithful encodings of Type 3 grammars. We show that it is impossible to provide a faithful encoding of Type 2 grammars and that termination-preserving CCS! processes can generate languages which are not Type 2. We finally show that the languages generated by termination-preserving CCS! processes are Type 1
On differentiation and homeostatic behaviours of Boolean dynamical systems

International audienceWe study rules proposed by the biologist R. Thomas relating the structure of a concurrent system of interacting genes (represented by a signed directed graph called a regulatory graph) with its dynamical properties. We prove that the results in [10] are stable under projection, and this enables us to relax the assumptions under which they are valid. More precisely, we relate here the presence of a positive (resp. negative) circuit in a regulatory graph to a more general form of biological differentiation (resp. of homeostasis)
From Luttinger to Fermi liquids in organic conductors

This chapter reviews the effects of interactions in quasi-one dimensional
systems, such as the Bechgaard and Fabre salts, and in particular the Luttinger
liquid physics. It discusses in details how transport measurements both d.c.
and a.c. allow to probe such a physics. It also examine the dimensional
crossover and deconfinement transition occurring between the one dimensional
case and the higher dimensional one resulting from the hopping of electrons
between chains in the quasi-one dimensional structure.Comment: To be published In the book "The Physics of Organic Conductors and
  Superconductors", Springer, 2007, ed. A. Lebe
Communication-Wear: User Feedback as Part of a Co-Design Process

Communication-Wear is a clothing concept that augments the mobile phone by enabling expressive messages to be exchanged remotely, by conveying a sense of touch, and presence. It proposes to synthesise conventions and cultures of fashion with those of mobile communications, where there are shared attributes in terms of communication and expression. Using garment prototypes as research probes as part of an on-going iterative co-design process, we endeavoured to mobilise participants’ tacit knowledge in order to gauge user perceptions on touch communication in a lab-based trial. The aim of this study was to determine whether established sensory associations people have with the tactile qualities of textiles could be used as signs and metaphors for experiences, moods, social interactions and gestures, related to interpersonal touch. The findings are used to inspire new design ideas for textile actuators for use in touch communication in successive iterations
Collection Profiling for Collection Fusion in Distributed Information Retrieval Systems

Discovering resource descriptions and merging results obtained from remote search engines are two key issues in distributed information retrieval studies. In uncooperative environments, query-based sampling and normalizing scores based merging strategies are well-known approaches to solve such problems. However, such approaches only consider the content of the remote database and do not consider the retrieval performance. In this paper, we address the problem that in peer to peer information systems and argue that the performance of search engine should also be considered. We also proposed a collection profiling strategy which can discover not only collection content but also retrieval performance. Web-based query classification and two collection fusion approaches based on the collection profiling are also introduced in this paper. Our experiments show that our merging strategies are effective in merging results on uncooperative environment
A new algorithm to compute the distance between multi-dimensional histograms

Presentado al 12th Iberoamerican Congress on Pattern Recognition (CIARP-2007) celebrado en Valparaiso (Chile).The aim of this paper is to present a new algorithm to compute the distance between ndimensional histograms. There are some domains such as pattern recognition or image retrieval that use the distance between histograms at some step of the classification process. For this reason, some algorithms that find the distance between histograms have been proposed in the literature. Nevertheless, most of this research has been applied on one-dimensional histograms due to the computation of a distance between multi-dimensional histograms is very expensive. In this paper, we present an efficient method to compare multi dimensional histograms in O(z2), where z represents the number of bins.This work was supported by the project 'Integration of robust perception, learning, and navigation systems in mobile robotics' (J-0929).Peer Reviewe