pinecone/core-2020-05-10-deduplication huggingface dataset:
Vote validatability in Mix-Net-based eVoting

One way to build secure electronic voting systems is to use Mix-Nets, which break any correlation between voters and their votes. One of the characteristics of Mix-Net-based eVoting is that ballots are usually decrypted individually and, as a consequence, invalid votes can be detected during the tallying of the election. In particular, this means that the ballot does not need to contain a proof of the vote being valid. However, allowing for invalid votes to be detected only during the tally- ing of the election can have bad consequences on the reputation of the election. First, casting a ballot for an invalid vote might be considered as an attack against the eVoting system by non-technical people, who might expect that the system does not accept such ballots. Besides, it would be impossible to track the attacker due to the anonymity provided by the Mix-Net. Second, if a ballot for an invalid vote is produced by a software bug, it might be only detected after the election period has  nished. In particular, voters would not be able to cast a valid vote again. In this work we formalize the concept of having a system that detects invalid votes during the election period. In addition, we give a general construction of an eVoting system satisfying such property and an e - cient concrete instantiation based on well-studied assumptionsOne way to build secure electronic voting systems is to use Mix-Nets, which break any correlation between voters and their votes. One of the characteristics of Mix-Net-based eVoting is that ballots are usually decrypted individually and, as a consequence, invalid votes can be detected during the tallying of the election. In particular, this means that the ballot does not need to contain a proof of the vote being valid. However, allowing for invalid votes to be detected only during the tally- ing of the election can have bad consequences on the reputation of the election. First, casting a ballot for an invalid vote might be considered as an attack against the eVoting system by non-technical people, who might expect that the system does not accept such ballots. Besides, it would be impossible to track the attacker due to the anonymity provided by the Mix-Net. Second, if a ballot for an invalid vote is produced by a software bug, it might be only detected after the election period has  nished. In particular, voters would not be able to cast a valid vote again. In this work we formalize the concept of having a system that detects invalid votes during the election period. In addition, we give a general construction of an eVoting system satisfying such property and an e - cient concrete instantiation based on well-studied assumptionsPeer ReviewedPostprint (author's final draft
Multiphasic, multistructured and hierarchical strategies for cartilage regeneration

Cartilage tissue is a complex nonlinear, viscoelastic, anisotropic, and multiphasic material with a very low coefficient of friction, which allows to withstand millions of cycles of joint loading over decades of wear. Upon damage, cartilage tissue has a low self-reparative capacity due to the lack of neural connections, vascularization, and a latent pool of stem/chondroprogenitor cells. Therefore, the healing of articular cartilage defects remains a significant clinical challenge, affecting millions of people worldwide. A plethora of biomaterials have been proposed to fabricate devices for cartilage regeneration, assuming a wide range of forms and structures, such as sponges, hydrogels, capsules, fibers, and microparticles. In common, the fabricated devices were designed taking in consideration that to fully achieve the regeneration of functional cartilage it is mandatory a well-orchestrated interplay of biomechanical properties, unique hierarchical structures, extracellular matrix (ECM), and bioactive factors. In fact, the main challenge in cartilage tissue engineering is to design an engineered device able to mimic the highly organized zonal architecture of articular cartilage, specifically its spatiomechanical properties and ECM composition, while inducing chondrogenesis, either by the proliferation of chondrocytes or by stimulating the chondrogenic differentiation  of stem/chondro-progenitor cells. In this chapter we present the recent advances in the development of innovative and complex biomaterials that fulfill the required structural key elements for cartilage regeneration. In particular, multiphasic, multiscale, multilayered, and hierarchical strategies composed by single or multiple biomaterials combined in a welldefined structure will be addressed. Those strategies include biomimetic scaffolds mimicking the structure of articular cartilage or engineered scaffolds as models of research to fully understand the biological mechanisms that influence the regeneration of cartilage tissue
Enterprise-specific ontology-driven process modelling

Different process models are created within an enterprise by different modelers who use different enterprise terms. This hinders model interoperability and integration. A possible solution is formalizing the vocabulary used within the enterprise in an ontology and put this ontology as bases for constructing process models. Given that an enterprise is an evolving entity, the ontology needs to evolve to properly reflect the domain of the enterprise. This paper proposes an enterprise-specific ontology-driven process modelling method which tackles the two aforementioned issues by assisting the modeller in creating process models using terminology from the ontology and simultaneously supporting ontology enrichment with feedback from those models. When the modeller creates a model, matching mechanisms incorporated in the method are working together to suggest a list of ontological concepts that have a high potential to be useful for a particular modelling element. When the model is created, its quality is first evaluated from different perspectives to make sure that it can be used within the enterprise, and second to discover whether its feedback can be useful for the ontology. When the feedback is extracted, the proposed method incorporates guidelines on how to use this feedback
Discovering frequent patterns on agrometeorological data with TrieMotif

The “food safety” issue has concerned governments from several countries. The accurate monitoring of agriculture have become important specially due to climate change impacts. In this context, the development of new technologies for monitoring are crucial. Finding previously unknown patterns that frequently occur on time series, known as motifs, is a core task to mine the collected data. In this work we present a method that allows a fast and accurate time series motif discovery. From the experiments we can see that our approach is able to efficiently find motifs even when the size of the time series goes longer. We also evaluated our method using real data time series extracted from remote sensing images regarding sugarcane crops. Our proposed method was able to find relevant patterns, as sugarcane cycles and other land covers inside the same area, which are really useful for data analysis.FAPESPCNPqCAPESSticAmsudInternational Conference on Enterprise Information Systems - ICEIS (16. 2014 Lisbon
Using data mining for prediction of hospital length of stay: an application of the CRISP-DM Methodology

Hospitals are nowadays collecting vast amounts of data related with patient records. All this data hold valuable knowledge that can be used to improve hospital decision making. Data mining techniques aim precisely at the extraction of useful knowledge from raw data. This work describes an implementation of a medical data mining project approach based on the CRISP-DM methodology. Recent real-world data, from 2000 to 2013, were collected from a Portuguese hospital and related with inpatient hospitalization. The goal was to predict generic hospital Length Of Stay based on indicators that are commonly available at the hospitalization process (e.g., gender, age, episode type, medical specialty). At the data preparation stage, the data were cleaned and variables were selected and transformed, leading to 14 inputs. Next, at the modeling stage, a regression approach was adopted, where six learning methods were compared: Average Prediction, Multiple Regression, Decision Tree, Artiﬁcial Neural Network ensemble, Support Vector Machine and Random Forest. The best learning model was obtained by the Random Forest method, which presents a high quality coeﬃcient of determination value (0.81). This model was then opened by using a sensitivity analysis procedure that revealed three inﬂuential input attributes: the hospital episode type, the physical service where the patient is hospitalized and the associated medical specialty. Such extracted knowledge conﬁrmed that the obtained predictive model is credible and with potential value for supporting decisions of hospital managers
On the Number of Synchronizing Colorings of Digraphs

We deal with $k$-out-regular directed multigraphs with loops (called simply
\emph{digraphs}). The edges of such a digraph can be colored by elements of
some fixed $k$-element set in such a way that outgoing edges of every vertex
have different colors. Such a coloring corresponds naturally to an automaton.
The road coloring theorem states that every primitive digraph has a
synchronizing coloring.
  In the present paper we study how many synchronizing colorings can exist for
a digraph with $n$ vertices. We performed an extensive experimental
investigation of digraphs with small number of vertices. This was done by using
our dedicated algorithm exhaustively enumerating all small digraphs. We also
present a series of digraphs whose fraction of synchronizing colorings is equal
to $1-1/k^d$, for every $d \ge 1$ and the number of vertices large enough.
  On the basis of our results we state several conjectures and open problems.
In particular, we conjecture that $1-1/k$ is the smallest possible fraction of
synchronizing colorings, except for a single exceptional example on 6 vertices
for $k=2$.Comment: CIAA 2015. The final publication is available at
  http://link.springer.com/chapter/10.1007/978-3-319-22360-5_1
Checking Whether an Automaton Is Monotonic Is NP-complete

An automaton is monotonic if its states can be arranged in a linear order
that is preserved by the action of every letter. We prove that the problem of
deciding whether a given automaton is monotonic is NP-complete. The same result
is obtained for oriented automata, whose states can be arranged in a cyclic
order. Moreover, both problems remain hard under the restriction to binary
input alphabets.Comment: 13 pages, 4 figures. CIAA 2015. The final publication is available at
  http://link.springer.com/chapter/10.1007/978-3-319-22360-5_2
Efficient point-based trajectory search

LNCS v. 9239 entitled: Advances in Spatial and Temporal Databases: 14th International Symposium, SSTD 2015, Hong Kong, China, August 26-28, 2015. ProceedingsTrajectory data capture the traveling history of moving objects such as people or vehicles. With the proliferation of GPS and tracking technology, huge volumes of trajectories are rapidly generated and collected. Under this, applications such as route recommendation and traveling behavior mining call for efficient trajectory retrieval. In this paper, we first focus on distance-based trajectory search; given a collection of trajectories and a set query points, the goal is to retrieve the top-k trajectories that pass as close as possible to all query points. We advance the state-of-the-art by combining existing approaches to a hybrid method and also proposing an alternative, more efficient rangebased approach. Second, we propose and study the practical variant of bounded distance-based search, which takes into account the temporal characteristics of the searched trajectories. Through an extensive experimental analysis with real trajectory data, we show that our rangebased approach outperforms previous methods by at least one order of magnitude. © Springer International Publishing Switzerland 2015.postprin
Uncertain voronoi cell computation based on space decomposition

LNCS v. 9239 entitled: Advances in Spatial and Temporal Databases: 14th International Symposium, SSTD 2015 ... ProceedingsThe problem of computing Voronoi cells for spatial objects whose locations are not certain has been recently studied. In this work, we propose a new approach to compute Voronoi cells for the case of objects having rectangular uncertainty regions. Since exact computation of Voronoi cells is hard, we propose an approximate solution. The main idea of this solution is to apply hierarchical access methods for both data and object space. Our space index is used to efficiently find spatial regions which must (not) be inside a Voronoi cell. Our object index is used to efficiently identify Delauny relations, i.e., data objects which affect the shape of a Voronoi cell. We develop three algorithms to explore index structures and show that the approach that descends both index structures in parallel yields fast query processing times. Our experiments show that we are able to approximate uncertain Voronoi cells much more effectively than the state-of-the-art, and at the same time, improve run-time performance.postprin
A Generic Testing Framework for Test Driven Development of Robotic Systems

This paper proposes a generic framework for test driven development of robotic systems. The framework provides functionalities for developing and running unit tests in a language and middleware independent manner. Tests are developed as independent plug-ins to be loaded and executed by an automated tool. Moreover, a fixture manager prepares the setup (e.g., running robot drivers or simulator) and actively monitors that all the required resources are available before and during the execution of the tests. These functionalities effectively accelerate the development process and cover different levels of robotic system testing. The paper describes the framework and provides realistic examples to show how it has been used to support software development on our robotic platform
Symmetry Reduction Enables Model Checking of More Complex Emergent
  Behaviours of Swarm Navigation Algorithms

The emergent global behaviours of robotic swarms are important to achieve
their navigation task goals. These emergent behaviours can be verified to
assess their correctness, through techniques like model checking. Model
checking exhaustively explores all possible behaviours, based on a discrete
model of the system, such as a swarm in a grid. A common problem in model
checking is the state-space explosion that arises when the states of the model
are numerous. We propose a novel implementation of symmetry reduction, in the
form of encoding navigation algorithms relatively with respect to a reference,
based on the symmetrical properties of swarms in grids. We applied the relative
encoding to a swarm navigation algorithm, Alpha, modelled for the NuSMV model
checker. A comparison of the state-space and verification results with an
absolute (or global) and a relative encoding of the Alpha algorithm highlights
the advantages of our approach, allowing model checking larger grid sizes and
number of robots, and consequently, verifying more complex emergent behaviours.
For example, a property was verified for a grid with 3 robots and a maximum
allowed size of 8x8 cells in a global encoding, whereas this size was increased
to 16x16 using a relative encoding. Also, the time to verify a property for a
swarm of 3 robots in a 6x6 grid was reduced from almost 10 hours to only 7
minutes. Our approach is transferable to other swarm navigation algorithms.Comment: Accepted for presentation in Towards Autonomous Robotic Systems
  (TAROS) 2015, Liverpool, U
Robotic Pseudo-Dynamic Testing (RPsDT) of Contact-Impact Scenarios

This paper presents a hybrid test method that enables the investigation of contact-impact scenarios in complex systems using kinematically versatile, off-the-shelf industrial robots. Based on the pseudo-dynamic test method, the technique conducts tests on an enlarged time scale, thereby circumventing control rate and response time limitations of the transfer system. An initial exploratory study of a drop test demonstrates that non-rate dependant effects including non-linear stiffness and structural hysteresis can be captured accurately while limitations result from the neglect of rate- and time-dependant effects such as viscous damping and creep. Future work will apply the new method to contact scenarios in air-to-air refuelling
On noise prediction in maps obtained with global DIC

International audienceA predictive formula giving the measurement resolution in displacement maps obtained using Digital Image Correlation was proposed some years ago in the literature. The objective of this paper is to revisit this formula and to propose a more general one which takes into account the influence of subpixel interpolation for the displacement. Moreover, a noiseless DIC tangent operator is defined to also minimize noise propagation from images to displacement maps. Simulated data enable us to assess the improvement brought about by this approach. The experimental validation is then carried out by assessing the noise in displacement maps deduced from a stack of images corrupted by noise. It is shown that specific image pre-processing tools are required to correctly predict the displacement resolution. This image pre-processing step is necessary to correctly account for the fact that noise in images is signal-dependent, and to get rid of parasitic micro-movements between camera and specimen that were experimentally observed and which corrupt noise estimation. Obtained results are analyzed and discussed
Certified Reduced Basis Methods for Parametrized Partial Differential Equations

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-319-22470-1International audienceThis book provides a thorough introduction to the mathematical and algorithmic aspects of certified reduced basis methods for parametrized partial differential equations. Central aspects ranging from model construction, error estimation and computational efficiency to empirical interpolation methods are discussed in detail for coercive problems. More advanced aspects associated with time-dependent problems, non-compliant and non-coercive problems and applications with geometric variation are also discussed as examples
Electronic data safes as an infrastructure for transformational government? A case study

This article introduces and explores the potential of an active electronic data safe (AEDS) serving as an infrastructure to achieve transformational government. An AEDS connects individuals and organizations from the private and the public sector to exchange information items related to business processes following the user-managed access paradigm. To realize the transformational government’s vision of user-centricity, fundamental changes in the service provision and collaboration of public and private sector organizations are needed. Findings of a user study with a prototype of an AEDS are used to identify four barriers for the adoption of an AEDS in the light of transformational government: (1.) offering citizens unfamiliar services having the character of experience-goods; (2.) failing to fulfill common service expectations of the customers; (3.) failing to establish contextual integrity for data sharing, and, (4.) failing to establish and run an AEDS as a multi-sided platform providing an attractive business model
Joint decompositions with flexible couplings

International audienceA Bayesian framework is proposed to define flexible coupling models for joint decompositions of data sets. Under this framework, a solution to the joint decomposition can be cast in terms of a maximum a posteriori estimator. Examples of joint posterior distributions are provided , including general Gaussian priors and non Gaussian coupling priors. Then simulations are reported and show the effectiveness of this approach to fuse information from data sets, which are inherently of different size due to different time resolution of the measurement devices
Joint Independent Subspace Analysis: A Quasi-Newton Algorithm

International audienceIn this paper, we present a quasi-Newton (QN) algorithm for joint independent subspace analysis (JISA). JISA is a recently proposed generalization of independent vector analysis (IVA). JISA extends classical blind source separation (BSS) to jointly resolve several BSS problems by exploiting statistical dependence between latent sources across mixtures, as well as relaxing the assumption of statistical independence within each mixture. Algebraically, JISA based on second-order statistics amounts to coupled block diagonalization of a set of covariance and cross-covariance matrices, as well as block diagonalization of a single permuted covariance matrix. The proposed QN algorithm achieves asymptotically the minimal mean square error (MMSE) in the separation of multidimensional Gaussian components. Numerical experiments demonstrate convergence and source separation properties of the proposed algorithm
Audio-Visual Speech-Turn Detection and Tracking

International audienceSpeaker diarization is an important component of multi-party dialog systems in order to assign speech-signal segments among participants. Diariza-tion may well be viewed as the problem of detecting and tracking speech turns. It is proposed to address this problem by modeling the spatial coincidence of visual and auditory observations and by combining this coincidence model with a dynamic Bayesian formulation that tracks the identity of the active speaker. Speech-turn tracking is formulated as a latent-variable temporal graphical model and an exact inference algorithm is proposed. We describe in detail an audiovisual discriminative observation model as well as a state-transition model. We also describe an implementation of a full system composed of multi-person visual tracking, sound-source localization and the proposed online diarization technique. Finally we show that the proposed method yields promising results with two challenging scenarios that were carefully recorded and annotated
Blind Source Separation in Nonlinear Mixture for Colored Sources Using Signal Derivatives

International audienceWhile Blind Source Separation (BSS) for linear mixtures has been well studied, the problem for nonlinear mixtures is still thought not to have a general solution. Each of the techniques proposed for solving BSS in nonlinear mixtures works mainly on specific models and cannot be generalized for many other realistic applications. Our approach in this paper is quite different and targets the general form of the problem. In this advance, we transform the nonlinear problem to a time-variant linear mixtures of the source derivatives. The proposed algorithm is based on separating the derivatives of the sources by a modified novel technique that has been developed and specialized for the problem, which is followed by an integral operator for reconstructing the sources. Our simulations show that this method separates the nonlinearly mixed sources with outstanding performance; however , there are still a few more steps to be taken to get to a comprehensive solution which are mentioned in the discussion
Theoretical Studies and Algorithms Regarding the Solution of Non-invertible Nonlinear Source Separation

International audienceIn this paper, we analyse and solve a source separation problem based on a mixing model that is nonlinear and non-invertible at the space of mixtures. The model is relevant considering it may represent the data obtained from ion-selective electrode arrays. We apply a new approach for solving the problems of local stability of the recurrent network previously used in the literature, which allows for a wider range of source concentration. In order to achieve this, we utilize a second-order recurrent network which can be shown to be locally stable for all solutions. Using this new network and the priors that chemical sources are continuous and smooth, our proposal performs better than the previous approach