pinecone/core-2020-05-10-deduplication huggingface dataset:
Total Variation Restoration of Images Corrupted by Poisson Noise with Iterated Conditional Expectations

International audienceInterpreting the celebrated Rudin-Osher-Fatemi (ROF) model in a Bayesian framework has led to interesting new variants for Total Variation image denoising in the last decade. The Posterior Mean variant avoids the so-called staircasing artifact of the ROF model but is computationally very expensive. Another recent variant, called TV-ICE (for Iterated Conditional Expectation), delivers very similar images but uses a much faster fixed-point algorithm. In the present work, we consider the TV-ICE approach in the case of a Poisson noise model. We derive an explicit form of the recursion operator, and show linear convergence of the algorithm, as well as the absence of staircasing effect. We also provide a numerical algorithm that carefully handles precision and numerical overflow issues, and show experiments that illustrate the interest of this Poisson TV-ICE variant
New Approximation of a Scale Space Kernel on SE(3) and Applications in
  Neuroimaging

We provide a new, analytic kernel for scale space filtering of dMRI data. The
kernel is an approximation for the Green's function of a hypo-elliptic
diffusion on the 3D rigid body motion group SE(3), for fiber enhancement in
dMRI. The enhancements are described by linear scale space PDEs in the coupled
space of positions and orientations embedded in SE(3). As initial condition for
the evolution we use either a Fiber Orientation Distribution (FOD) or an
Orientation Density Function (ODF). Explicit formulas for the exact kernel do
not exist. Although approximations well-suited for fast implementation have
been proposed in literature, they lack important symmetries of the exact
kernel. We introduce techniques to include these symmetries in approximations
based on the logarithm on SE(3), resulting in an improved kernel. Regarding
neuroimaging applications, we apply our enhancement kernel (a) to improve dMRI
tractography results and (b) to quantify coherence of obtained streamline
bundles.Comment: 12 pages, 4 figures, SSVM 201
Morphological Scale-Space Operators for Images Supported on Point Clouds

International audienceThe aim of this paper is to develop the theory, and to propose an algorithm, for morphological processing of images painted on point clouds, viewed as a length metric measure space $(X,d,\mu)$. In order to extend morphological operators to process point cloud supported images, one needs to define dilation and erosion as semigroup operators on $(X,d)$. That corresponds to a supremal convolution (and infimal convolution) using admissible structuring function on $(X,d)$. From a more theoretical perspective, we introduce the notion of abstract structuring functions formulated on length metric Maslov idempotent measurable spaces, which is the appropriate setting for $(X,d)$. In practice, computation of Maslov structuring function is approached by a random walks framework to estimate heat kernel on $(X,d,\mu)$, followed by the logarithmic trick
O-PSI : delegated private set intersection on outsourced datasets

Private set intersection (PSI) has a wide range of applications such as privacy-preserving data mining. With the advent of cloud computing it is now desirable to take advantage of the storage and computation capabilities of the cloud to outsource datasets and delegate PSI computation. In this paper we design OPSI, a protocol for delegated private set intersection on outsourced datasets based on a novel point-value polynomial representation. Our protocol allows multiple clients to independently prepare and upload their private datasets to a server, and then ask the server to calculate their intersection. The protocol ensures that intersections can only be calculated with the permission of all clients and that datasets and results remain completely confidential from the server. Once datasets are outsourced, the protocol supports an unlimited number of intersections with no need to download them or prepare them again for computation. Our protocol is efficient and has computation and communication costs linear to the cardinality of the datasets. We also provide a formal security analysis of the protocol
Authenticated file broadcast protocol

The File Broadcast Protocol (FBP) was developed as a part of the DETIboot system. DETIboot allows a host to broadcast an operating system image through an 802.11 wireless network to an arbitrary number of receivers. Receivers can load the image and immediately boot a Linux live session. The initial version of FBP had no security mechanisms. In this paper we present an authentication protocol developed for FBP that ensures a correct file distribution from the intended source to the receivers. The performance valuations have shown that, with the best operational configuration tested, the file download time is increased by less than 5%
A Survey of Alerting Websites: Risks and Solutions

International audienceIn the recent years an incredible amount of data has been leaked from major websites such as Adobe, Snapchat and LinkedIn. There are hundreds of millions of usernames, email addresses, passwords, telephone numbers and credit card details in the wild. The aftermath of these breaches is the rise of alerting websites such as haveibeenpwned.com, which let users verify if their accounts have been compromised. Unfortunately, these seemingly innocuous websites can be easily turned into phishing tools. In this work, we provide a comprehensive study of the most popular ones. Our study exposes the associated privacy risks and evaluates existing solutions towards designing privacy-friendly alerting websites. In particular, we study three solutions: private set intersection, private set intersection cardinality and private information retrieval adapted to membership testing. Finally, we investigate the practicality of these solutions with respect to real world database leakages
An architecture for trustworthy open data services

This paper addresses the development of trust in the use of Open Data through incorporation of appropriate authentication and integrity parameters for use by end user Open Data application developers in an architecture for trustworthy Open Data Services. The advantages of this architecture scheme is that it is far more scalable, not another certificate-based hierarchy that has problems with certificate revocation management. With the use of a Public File, if the key is compromised: it is a simple matter of the single responsible entity replacing the key pair with a new one and re-performing the data file signing process. Under this proposed architecture, the the Open Data environment does not interfere with the internal security schemes that might be employed by the entity. However, this architecture incorporates, when needed, parameters from the entity, e.g. person who authorized publishing as Open Data, at the time that datasets are created/added
Web application for LTI systems analysis

The number of web-applications which employ external computing tools to perform complex calculations on-line is rising. This contribution presents one such application – web-interface for analysis of linear timeinvariant (LTI) systems. It is based on the interconnection of the MATLAB system with the latest web technologies and developer tools. It enables to analyze a single input – single output (SISO) system in a user-defined form and a userfriendly way on-line without the necessity to install the MATLAB environment or similar computing tools. The paper explains motivation for development of this site and gives also detailed description of the whole process including the Web – MATLAB interconnection. The results are presented using selected screen-shots of the site on a simple example of a LTI system analysis. © Springer International Publishing Switzerland 2015
Predictive control of systems with fast dynamics using computational reduction based on feedback control information

Predictive control is a method, which is suitable for control of linear discrete dynamical systems. However, control of systems with fast dynamics could be problematic using predictive control. The calculation of a predictivecontrol algorithm can exceed the sampling period. This situation occurs in case with higher prediction horizons and many constraints on variables in the predictive control. In this contribution, an improving of the classical approach is presented. The reduction of the computational time is performed using an analysis of steady states in the control. The presented approach is based on utilization of information from the feedback control. Then this information is applied in the control algorithm. Finally, the classical method is compared to the presented modification using the time analyses. © Springer International Publishing Switzerland 2015
On the influence of high priority customers on a generalized processor sharing queue

In this paper, we study a hybrid scheduling mechanism in discrete-time. This mechanism combines the well-known Generalized Processor Sharing (GPS) scheduling with strict priority. We assume three customer classes with one class having strict priority over the other classes, whereby each customer requires a single slot of service. The latter share the remaining bandwith according to GPS. This kind of scheduling is used in practice for the scheduling of jobs on a processor and in Quality of Service modules of telecommunication network devices. First, we derive a functional equation of the joint probability generating function of the queue contents. To explicitly solve the functional equation, we introduce a power series in the weight parameter of GPS. Subsequently, an iterative procedure is presented to calculate consecutive coefficients of the power series. Lastly, the approximation resulting from a truncation of the power series is verified with simulation results. We also propose rational approximations. We argue that the approximation performs well and is extremely suited to study these systems and their sensitivity in their parameters (scheduling weights, arrival rates, loads ...). This method provides a fast way to observe the behaviour of such type of systems avoiding time-consuming simulations
What Do Practitioners Vary in Using Scrum?

Background: Agile software development has become a popular way of developing
software. Scrum is the most frequently used agile framework, but it is often
reported to be adapted in practice. Objective: Thus, we aim to understand how
Scrum is adapted in different contexts and what are the reasons for these
changes. Method: Using a structured interview guideline, we interviewed ten
German companies about their concrete usage of Scrum and analysed the results
qualitatively. Results: All companies vary Scrum in some way. The least
variations are in the Sprint length, events, team size and requirements
engineering. Many users varied the roles, effort estimations and quality
assurance. Conclusions: Many variations constitute a substantial deviation from
Scrum as initially proposed. For some of these variations, there are good
reasons. Sometimes, however, the variations are a result of a previous
non-agile, hierarchical organisation.Comment: 12 page
A Survey on Multimodal Biometrics and the Protection of their Templates

In order to guarantee better user-friendliness and higher accuracy, beyond the existing traditional single-factor biometric systems, the  multimodal  ones  appear  to  be  more  promising.  Two  or  more  bio-
metric  measurements  for  the  same  identity  are  extracted,  stored  and compared during the enrollment, authentication and identi cation processes. Deployed multimodal biometric systems also referred to as multibiometrics or even as multimodalities are commonly found and used in electronic chips embedded in travel documents. The widespread use of such systems, the nature of the shared data and the importance of applications introduces privacy risks. A signi cant number of approaches and very recent advances to the relevant protection technologies have been published. This paper illustrates a comprehensive overview of research in multibiometrics, the protection of their templates and the privacy issues that arise. Up-to-date review of the existing literature revealing the current state-of-art suggestions is provided, based on the di erent levels of fusion and the employed protection algorithms, while an outlook to future prospects is also discussed.status: publishe
Fractal zeta functions and complex dimensions: A general
  higher-dimensional theory

In 2009, the first author introduced a class of zeta functions, called
`distance zeta functions', which has enabled us to extend the existing theory
of zeta functions of fractal strings and sprays (initiated by the first author
and his collaborators in the early 1990s) to arbitrary bounded (fractal) sets
in Euclidean spaces of any dimensions. A closely related tool is the class of
`tube zeta functions', defined using the tube function of a fractal set. These
zeta functions exhibit deep connections with Minkowski contents and upper box
(or Minkowski) dimensions, as well as, more generally, with the complex
dimensions of fractal sets. In particular, the abscissa of (Lebesgue, i.e.,
absolute) convergence of the distance zeta function coincides with the upper
box dimension of a set. We also introduce a class of transcendentally
quasiperiodic sets, and describe their construction based on a sequence of
carefully chosen generalized Cantor sets with two auxilliary parameters. As a
result, we obtain a family of "maximally hyperfractal" compact sets and
relative fractal drums (i.e., such that the associated fractal zeta functions
have a singularity at every point of the critical line of convergence).
Finally, we discuss the general fractal tube formulas and the Minkowski
measurability criterion obtained by the authors in the context of relative
fractal drums (and, in particular, of bounded subsets of the N-dimensional
Euclidean space).Comment: For inclusion in the Proceedings of the International Conference
  "Geometry and Stochastics V," Tabarz, Germany, March 2014, Progress in
  Probability, Birkh\"auser, Basel, Boston and Berlin, 2015, C. Bandt, K.
  Falconer and M. Z\"ahle, eds.; based on a plenary lecture given by the first
  author at that conference, 29 pages, corrected Equations (26) and (27) and
  the 2nd sentence after Equation (46
Some recent developments in quantization of fractal measures

We give an overview on the quantization problem for fractal measures,
including some related results and methods which have been developed in the
last decades. Based on the work of Graf and Luschgy, we propose a three-step
procedure to estimate the quantization errors. We survey some recent progress,
which makes use of this procedure, including the quantization for self-affine
measures, Markov-type measures on graph-directed fractals, and product measures
on multiscale Moran sets. Several open problems are mentioned.Comment: 13 page
An Introduction to Francophone perspectives of learning through work

Professional learning, and the educational and practice-based experiences that support it, are currently the subject of increased interest and attention in the fields of educational, psychological, sociological, and business management research and teaching. They are also becoming priorities for governments, employer organisations, professional bodies and unions who are commonly concerned with developing and sustaining competent workforces and workers to meet important personal, workplace and national social and economic goals. Yet, the current body of research dedicated to understanding learning through and for occupational practice appears as dispersed and not sufficiently integrated. Across various disciplinary, linguistic and cultural contexts, specific methodological, theoretical and organisational avenues have been elaborated in response to the challenges of practice-based learning, yet often with little references to the diversity and richness of approaches available in the field. For instance, the research perspectives adopted in the Francophone context have come to comprise specific traditions, some of which are widely shared internationally, whereas others have acquired a strong visibility only in French-speaking countries, and in some cases only in one country. However, these conceptions are largely unknown outside of the Francophone world and are often inaccessible to the English-speaking audience. The objective of this chapter is to introduce the project this book, which is to make available to an English-speaking audience key conceptualisations, methods and empirical findings that have emerged within Francophone countries on the topic of learning through practice. The chapter explains the rationale and genesis of this book project and provides an overview of the contributions that comprise content of the seventeen chapters of the monograph.Full Tex
A Note on the Existence of Self-Dual Skew Codes over Finite Fields

ISBN : 978-3-319-18680-1International audienceConditions on the existence of self-dual θ-codes defined over a finite field IF q are studied for θ automorphism of IF q. When q ≡ 1 (mod 4) it is proven that there always exists a self-dual θ-code in any dimension and that self-dual θ-codes of a given dimension are either all θ-cyclic or all θ-negacyclic. When q ≡ 3 (mod 4), there does not exist a self-dual θ-cyclic code and a necessary and sufficient condition for the existence of self-dual θ-negacyclic codes is given
Failure of the Point Blinding Countermeasure Against Fault Attack in Pairing-Based Cryptography

Article published in the proceedings of the C2SI conference, May 2015.Pairings are mathematical tools that have been proven to be very useful in the construction of many cryptographic protocols. Some of these protocols are suitable for implementation on power constrained devices such as smart cards or smartphone which are subject to side channel attacks. In this paper, we analyse the efficiency of the point blinding countermeasure in pairing based cryptography against side channel attacks. In particular,we show that this countermeasure does not protect Miller's algorithm for pairing computation against fault attack. We then give recommendation for a secure implementation of a pairing based protocol using the Miller algorithm
ITSM ProcessGuide – A process guidance system for IT service management

Process Guidance aims at increasing the process model understanding and effective and efficient process execution. In this paper we present the context, design, implementation, and ongoing evaluation of a Process Guidance System instantiation in an organizational setting. The system is used to support the IT Service Management processes within the case company. It is used productively in the case company of this research and this article describes how the system’s features are designed for the evaluation
An Automated Assay for the Evaluation of Mortality in Fish Embryo

International audienceWaterways are often first and severely affected by pollution. In this context, fish embryos – which constitute a good model for sensitivity to chemicals – are widely used in environmental toxicology studies. Such studies are devoted to the analysis of a wide spectrum of physiological parameters, for instance mortality ratio. In this article, we develop an assay to determine the mortality rate of Medaka embryo. Based on video sequences, our purpose is to obtain reliable, repeatable results in a fully automated fashion. To reach that challenging goal, we develop an efficient morphological pipeline that analyses image sequences in a multiscale paradigm, from the global scene to the embryo, and then to its heart, finally analysing its putative motion, characterized by intensity variations. Our pipeline, based on robust morphological operators, has a low computational cost, and was experimentally assessed on a dataset consisting of 660 images, providing a success ratio higher than 99%
The waterfall hierarchy on weighted graphs

International audienceWe study and present two new algorithms for constructing the waterfall hierarchy of a topographic surface. The first models a topographic surface as a flooding graph, each node representing a lake filling a catchment basin up to its lowest pass point ; each edge representing such a pass point. It It makes use of the equivalence of node and edge weighted graphs, passing from one type to the other during as the algorithm proceeds. The second algorithm produces the waterfall partition in one pass through the edges of a minimum spanning tree of the region adjacency graph associated to a topographic surface
N-ary Mathematical Morphology

International audienceMathematical morphology on binary images can be fully de-scribed by set theory. However, it is not sucient to formulate mathe-matical morphology for grey scale images. This type of images requires the introduction of the notion of partial order of grey levels, together with the denition of sup and inf operators. More generally, mathemati-cal morphology is now described within the context of the lattice theory. For a few decades, attempts are made to use mathematical morphology on multivariate images, such as color images, mainly based on the no-tion of vector order. However, none of these attempts has given fully satisfying results. Instead of aiming directly at the multivariate case we propose an extension of mathematical morphology to an intermediary situation: images composed of a nite number of independent unordered categories
Portal Extraction Based on an Opening Labeling for Ray Tracing

International audienceRendering photo-realistic images from a 3D scene description remains a challenging problem when processing complex geometry exposing many occlusions. In that case, simulating light propagation requires hours to produce a correct image. An opening map can be used to extract information from the geometry of the empty space of a scene, where light travels. It describes local thickness and allows to identify narrow regions that are difficult to traverse with ray tracing. We propose a new method to extract portals in order to improve rendering algorithms based on ray tracing. This method is based on the opening map, which is used to define a labeling of the empty space. Then portals-2D surfaces embedded in empty space-are extracted from labeled regions. We demonstrate that those portals can be sampled in order to explore the scene efficiently with ray tracing
Ordering on the probability simplex of endmembers for hyperspectral morphological image processing

International audienceA hyperspectral image can be represented as a set of ma-terials called endmembers, where each pixel corresponds to a mixture of several of these materials. More precisely pixels are described by the quantity of each material, this quantity is often called abundance and is positive and of sum equal to one. This leads to characterize a hyper-spectral image as a set of points in a probability simplex. The geometry of the simplex has been particularly studied in the theory of quantum information, giving rise to different notions of distances and interesting preorders. In this paper, we present total orders based on theory of the ordering on the simplex. Thanks to this theory, we can give a physical interpretation of our orders
Bagging Stochastic Watershed on Natural Color Image Segmentation

International audienceThe stochastic watershed is a probabilistic segmentation ap-proach which estimates the probability density of contours of the image from a given gradient. In complex images, the stochastic watershed can enhance insignificant contours. To partially address this drawback, we introduce here a fully unsupervised multi-scale approach including bag-ging. Re-sampling and bagging is a classical stochastic approach to im-prove the estimation. We have assessed the performance, and compared to other version of stochastic watershed, using the Berkeley segmentation database