pinecone/core-2020-05-10-deduplication huggingface dataset:
Clustering of high-dimensional and correlated data

Finite mixture models are being commonly used in a wide range of applications  in practice concerning density estimation and clustering. An attractive  feature of this approach to clustering is that it provides a sound statistical framework  in which to assess the important question of how many clusters there are in  the data and their validity. We consider the applications of normal mixture models  to high-dimensional data of a continuous nature. One way to handle the fitting of  normal mixture models is to adopt mixtures of factor analyzers. However, for extremely  high-dimensional data, some variable-reduction method needs to be used  in conjunction with the latter model such as with the procedure called EMMIXGENE.  It was developed for the clustering of microarray data in bioinformatics, but  is applicable to other types of data. We shall also consider the mixture procedure  EMMIX-WIRE (based on mixtures of normal components with random effects),  which is suitable for clustering high-dimensional data that may be structured (correlated and and replicated) as in longitudinal studies.Full Tex
Non-strongly stable orders also define interesting simulation relations

We present a study of the notion of coalgebraic simulation introduced by Hughes and Jacobs. Although in their original paper they allow any functorial order in their definition of coalgebraic simulation, for the simulation relations to have good properties they focus their attention on functors with orders which are strongly stable. This guarantees a so-called “composition-preserving” property from which all the desired good properties follow. We have noticed that the notion of strong stability not only ensures such good properties but also “distinguishes the direction” of the simulation. For example, the classic notion of simulation for labeled transition systems, the relation “p is simulated by q”, can be defined as a coalgebraic simulation relation by means of a strongly stable order, whereas the opposite relation, “p simulates q”, cannot. Our study was motivated by some interesting classes of simulations that illustrate the application of these results: covariant-contravariant simulations and conformance simulations
Correctness, completeness and termination of pattern-based model-to-model transformation

The final publication is available at Springer via http://dx.doi.org/10.1007/978-3-642-03741-2_26Proceedings of Third International Conference, CALCO 2009, Udine, Italy, September 7-10, 2009.Model-to-model (M2M) transformation consists in trans- forming models from a source to a target language. Many transformation languages exist, but few of them combine a declarative and relational style with a formal underpinning able to show properties of the transformation. Pattern-based transformation is an algebraic, bidirectional, and relational approach to M2M transformation. Specifications are made of patterns stating the allowed or forbidden relations between source and target models, and then compiled into low level operational mechanisms to perform source-to-target or target-to-source transformations. In this paper, we study the compilation into operational triple graph grammar rules and show: (i) correctness of the compilation of a specification without negative patterns; (ii) termination of the rules, and (iii) completeness, in the sense that every model considered relevant can be built by the rules.Work supported by the Spanish Ministry of Science and Innovation, projects METEORIC (TIN2008-02081), MODUWEB (TIN2006-09678) and FORMALISM (TIN2007-66523). Moreover, part of this work was done during a sabbatical leave of the first author at TU Berlin, with financial support from the Spanish Ministry of Science and Innovation (grant ref. PR2008-0185). We thank the referees for their useful comment
An MDA-Based Environment for Generating Access Control Policies

Identity management and access control are essential in the enterprise IT landscape in order to control access to applications and to fulfil laws or regulations. The global competition of enterprises leads to short development cycles and fast changes of IT applications, which requires also an error-free and quick adaption of its security. The model-driven development of access control policies promises to cope with this situation. This work introduces an mda-based environment for generating access control policies. A comprehensive overview is given on the organisational aspects, describing details of roles, artefacts and tools involved. On this basis the four phases of a model-driven development process for access control policies and their organisational aspects are presented
A Privacy-Preserving Platform for User-Centric Quantitative Benchmarking

We propose a centralised platform for quantitative benchmarking of key performance indicators (KPI) among mutually distrustful organisations. Our platform offers users the opportunity to request an ad-hoc benchmarking for a specific KPI within a peer group of their choice. Architecture and protocol are designed to provide anonymity to its users and to hide the sensitive KPI values from other clients and the central server. To this end, we integrate user-centric peer group formation, exchangeable secure multi-party computation protocols, short-lived ephemeral key pairs as pseudonyms, and attribute certificates. We show by empirical evaluation of a prototype that the performance is acceptable for reasonably sized peer groups
Overview of the INEX 2008 Interactive Track

This paper presents the organization of the INEX 2008 interactive track. In this year’s iTrack we aimed at exploring the value of element retrieval for two different task types, fact-finding and research tasks. Two research groups collected data from 29 test persons, each performing two tasks. We describe the methods used for data collection and the tasks performed by the participants. A general result indicates that test persons were more satisfied when completing research task compared to fact-finding task. In our experiment, test persons regarded the research task easier, were more satisfied with the search results and found more relevant information for the research tasks
Clustering XML documents using frequent subtrees

This paper presents an experimental study conducted over the INEX 2008 Document Mining Challenge corpus using both the structure and the content of XML documents for clustering them. The concise common substructures known as the closed frequent subtrees are generated using the structural information of the XML documents. The closed frequent subtrees are then used to extract the constrained content from the documents. A matrix containing the term distribution of the documents in the dataset is developed using the extracted constrained content. The k-way clustering algorithm is applied to the matrix to obtain the required clusters. In spite of the large number of documents in the INEX 2008 Wikipedia dataset, the proposed frequent subtree-based clustering approach was successful in clustering the documents. This approach significantly reduces the dimensionality of the terms used for clustering without much loss in accuracy
Significance tests and statistical inequalities for segmentation by region growing on graph

International audienceBottom-up segmentation methods merge similar neighboring regions according to a decision rule and a merging order. In this paper, we propose a contribution for each of these two points. Firstly, under statistical hypothesis of similarity, we provide an improved decision rule for region merging based on significance tests and the recent statistical inequality of McDiarmid. Secondly, we propose a dynamic merging order based on our merging predicate. This last heuristic is justified by considering an energy minimisation framework. Experimental results on both natural and medical images show the validity of our method
The role of social networking services in eParticipation

Published version of a chapter published in Lecture Notes in Computer Science, 5694, 46-55. Also available from the publisher at: http://dx.doi.org/10.1007/978-3-642-03781-8_5A serious problem in eParticipation projects is citizen engagement – citizens do not necessarily become more willing to participate simply because net-services are provided for them. Most forms of eParticipation in democratic contexts are, however, dependent on citizen engagement, interaction and social networking because democratic systems favour the interests of larger groups of citizens – the more voices behind a political proposition, the greater its chances of success. In this context of challenges the study of social networking on the internet and social network theory offers valuable insights into the practices and theories of citizen engagement. Social network theory focuses on the chains of relationships that social actors communicate and act within. Some social networking services on the internet attract large numbers of users, and apparently sustain a great deal of interaction, content-generation and the development of loosely-coupled communities. They provide the forum for much discussion and interaction. In this respect social networking could contribute to solve some of the problems of engaging their users that eParticipation services often struggle with. This paper investigates the potential of Social Networking Services for the eParticipation area by defining social networking services, introducing the driving forces behind their advance, and discusses the potential use of social networking software in the eParticipation context
A two-level structure for compressing aligned bitexts

A bitext, or bilingual parallel corpus, consists of two texts, each one in a different language, that are mutual translations. Bitexts are very useful in linguistic engineering because they are used as source of knowledge for different purposes. In this paper we propose a strategy to efﬁciently compress and use bitexts, saving, not only space, but also processing time when exploiting them. Our strategy is based on a two-level structure for the vocabularies, and on the use of biwords, a pair of associated words, one from each language, as basic symbols to be encoded with an ETDC compressor. The resulting compressed bitext needs around 20% of the space and allows more efﬁcient implementations of the different types of searches and operations that linguistic engineerings need to perform on them. In this paper we discuss and provide results for compression, decompression, different types of searches, and bilingual snippets extraction.Spanish projects TIN2006-15071-C03-01, TIN2006-15071-C03-02 and TIN2006-15071-C03-03. Regional Government of Castilla y León and the European Social Fund
Use of Co-occurrences for temporal expressions annotation

The annotation or extraction of temporal information from text documents is becoming increasingly important in many natural language processing applications such as text summarization, information retrieval, question answering, etc.. This paper presents an original method for easy recognition of temporal expressions in text documents. The method creates semantically classified temporal patterns, using word co-occurrences obtained from training corpora and a pre-defined seed keywords set, derived from the used language temporal references. A participation on a Portuguese named entity evaluation contest showed promising effectiveness and efficiency results. This approach can be adapted to recognize other type of expressions or languages, within other contexts, by defining the suitable word sets and training corpora.FC
A Dichotomy Theorem for Polynomial Evaluation

A dichotomy theorem for counting problems due to Creignou and Hermann states that or any nite set S of logical relations, the counting problem #SAT(S) is either in FP, or #P-complete. In the present paper we show a dichotomy theorem for polynomial evaluation. That is, we show that for a given set S, either there exists a VNP-complete family of polynomials associated to S, or the associated families of polynomials are all in VP. We give a concise characterization of the sets S that give rise to "easy" and "hard" polynomials. We also prove that several problems which were known to be #P-complete under Turing reductions only are in fact #P-complete under many-one reductions
Synchronization of Regular Automata

International audienceFunctional graph grammars are finite devices which generate the class of regular automata. We recall the notion of synchronization by grammars, and for any given grammar we consider the class of languages recognized by automata generated by all its synchronized grammars. The synchronization is an automaton-related notion: all grammars generating the same automaton synchronize the same languages. When the synchronizing automaton is unambiguous, the class of its synchronized languages forms an effective boolean algebra lying between the classes of regular languages and unambiguous context-free languages. We additionally provide sufficient conditions for such classes to be closed under concatenation and its iteration
The longest path problem is polynomial on interval graphs. \ud

The longest path problem is the problem of finding a path of maximum length in a graph. Polynomial solutions for this problem are known only for small classes of graphs, while it is NP-hard on general graphs, as it is a generalization of the Hamiltonian path problem. Motivated by the work of Uehara and Uno in [20], where they left the longest path problem open for the class of interval graphs, in this paper we show that the problem can be solved in polynomial time on interval graphs. The proposed algorithm runs in O(n 4) time, where n is the number of vertices of the input graph, and bases on a dynamic programming approach. \u
Quantum algorithms to solve the hidden shift problem for quadratics and
  for functions of large Gowers norm

Most quantum algorithms that give an exponential speedup over classical
algorithms exploit the Fourier transform in some way. In Shor's algorithm,
sampling from the quantum Fourier spectrum is used to discover periodicity of
the modular exponentiation function. In a generalization of this idea, quantum
Fourier sampling can be used to discover hidden subgroup structures of some
functions much more efficiently than it is possible classically. Another
problem for which the Fourier transform has been recruited successfully on a
quantum computer is the hidden shift problem. Quantum algorithms for hidden
shift problems usually have a slightly different flavor from hidden subgroup
algorithms, as they use the Fourier transform to perform a correlation with a
given reference function, instead of sampling from the Fourier spectrum
directly. In this paper we show that hidden shifts can be extracted efficiently
from Boolean functions that are quadratic forms. We also show how to identify
an unknown quadratic form on n variables using a linear number of queries, in
contrast to the classical case were this takes Theta(n^2) many queries to a
black box. What is more, we show that our quantum algorithm is robust in the
sense that it can also infer the shift if the function is close to a quadratic,
where we consider a Boolean function to be close to a quadratic if it has a
large Gowers U_3 norm.Comment: 12 pages, no figures, Proc. MFCS'09, LNCS vol. 5734, pp. 663-674,
  2009. Mezzanine tranche of earlier paper arXiv:0811.320
On Pebble Automata for Data Languages with Decidable Emptiness Problem

In this paper we study a subclass of pebble automata (PA) for data languages
for which the emptiness problem is decidable. Namely, we introduce the
so-called top view weak PA. Roughly speaking, top view weak PA are weak PA
where the equality test is performed only between the data values seen by the
two most recently placed pebbles. The emptiness problem for this model is
decidable. We also show that it is robust: alternating, nondeterministic and
deterministic top view weak PA have the same recognition power. Moreover, this
model is strong enough to accept all data languages expressible in Linear
Temporal Logic with the future-time operators, augmented with one register
freeze quantifier.Comment: An extended abstract of this work has been published in the
  proceedings of the 34th International Symposium on Mathematical Foundations
  of Computer Science (MFCS) 2009}, Springer, Lecture Notes in Computer Science
  5734, pages 712-72
Testing cooperative communication schemes in a virtual distributed testbed of wireless networks

It is expected that Next Generation Networks (NGNs) will offer seamless interoperability among heterogeneous access technologies in order to provide ubiquitous access. In such settings, short range technologies may be used in order to extend the coverage area of cellular systems while cooperative diversity can improve the efficiency of the wireless systems. An advanced, backward compatible, with the 802.11 standard, MAC protocol for cooperative ARQ scenarios in NGNs sets the research framework for this work. The functionalities of the RCSMA protocol 1 will be enhanced and the derived analytical models will be validated at the UNITE Virtual Distributed Testbed (VDT) (2).Peer ReviewedPostprint (published version
An Online Mechanism for Multi-Speed Electric Vehicle Charging

As plug-in electric vehicles become more widespread, their charging needs to be coordinated, in order to ensure that capacity constraints are not exceeded.  This is becoming particularly critical as new fast-charging technologies are being developed that place additional burden on local transformers.  To address this problem, we propose a novel online mechanism in which agents representing vehicle owners are incentivised to be truthful not only about their marginal valuations for electricity units, but also about their arrival, departure and maximum charging speeds.  The work extends the state of the art in several ways.  We develop an online, model-free mechanism that handles multi-unit demand per period, thus accommodating vehicles with heterogeneous and ﬂexible charging speeds; we provide competitive worst-case bounds for our mechanism; ﬁnally, we simulate the proposed online mechanism using data from a real-world trial of electric vehicles in the UK, showing that using fast charging leads to signiﬁcant cost savings.Engineering and Applied Science
Fair Package Assignment

We consider the problem of fair allocation in the package assignment model, where a set of indivisible items, held by single seller, must be efficiently allocated to agents with quasi-linear utilities. A fair assignment is one that is efficient and envy-free. We consider a model where bidders have superadditive valuations, meaning that items are pure complements. Our central result is that core outcomes are fair and even coalition-fair over this domain, while fair distributions may not even exist for general valuations. Of relevance to auction design, we also establish that the core is equivalent to the set of anonymous-price competitive equilibria, and that superadditive valuations are a maximal domain that guarantees the existence of anonymous-price competitive equilibrium. Our results are analogs of core equivalence results for linear prices in the standard assignment model, and for nonlinear, non-anonymous prices in the package assignment model with general valuations.Engineering and Applied Science
Verification of concurrent programs with Chalice

A program verifier is a tool that allows developers to prove that their code satisfies its specification for every possible input and every thread schedule.  These lecture notes describe a verifier for concurrent programs called Chalice.

Chalice's verification methodology centers around permissions and permission transfer. In particular, a memory location may be accessed by a thread only if that thread has permission to do so. Proper use of permissions allows Chalice to deduce upper bounds on the set of locations modifiable by a method and guarantees the absence of data races for concurrent programs. The lecture notes informally explain how Chalice works through various examples.status: publishe
Enabling SAML for dynamic identity federation management

Proceedings of: The Second IFIP WG 6.8 Joint Conference, WMNC 2009, Gdansk, Poland, September 9-11, 2009Federation in identity management has emerged as a key concept for reducing complexity in the companies and offering an improved user experience when accessing services. In this sense, the process of trust establishment is fundamental to allow rapid and seamless interaction between different trust domains. However, the problem of establishing identity federations in dynamic and open environments that form part of Next Generation Networks (NGNs), where it is desirable to speed up the processes of service provisioning and deprovisioning, has not been fully addressed. This paper analyzes the underlying trust mechanisms of the existing frameworks for federated identity management and its suitability to be applied in the mentioned environments. This analysis is mainly focused on the Single Sign On (SSO) profile. We propose a generic extension for the SAML standard in order to facilitate the creation of federation relationships in a dynamic way between prior unknown parties. Finally, we give some details of implementation and compatibility issues
Dynamic Compartments in the Imperative Pi Calculus

International audienceDynamic compartments with mutable conﬁgurations and variable volumes are of basic interest for the stochastic modeling of biochemistry in cells. We propose a new language to express dynamic compartments that we call the imperative π-calculus. It is obtained from the attributed π-calculus by adding imperative assignment operations to a global store. Previous approaches to dynamic compartments are improved in ﬂexibility or efficiency. This is illustrated by an appropriate model of osmosis and a correct encoding of BioAmbients
The triconnected abstraction of process models

Companies use business process models to represent their working procedures in order to deploy services to markets, to analyze them, and to improve upon them. Competitive markets necessitate complex procedures, which lead to large process specifications with sophisticated structures. Real world process models can often incorporate hundreds of modeling constructs. While a large degree of detail complicates the comprehension of the processes, it is essential to many analysis tasks. This paper presents a technique to abstract, i.e., to simplify process models. Given a detailed model, we introduce abstraction rules which generalize process fragments in order to bring the model to a higher abstraction level. The approach is suited for the abstraction of large process specifications in order to aid model comprehension as well as decomposing problems of process model analysis. The work is based on process structure trees that have recently been introduced to the field of business process management
Enabling High Data Throughput in Desktop Grids Through Decentralized Data and Metadata Management: The BlobSeer Approach

International audienceWhereas traditional Desktop Grids rely on centralized servers for data management, some recent progress has been made to enable distributed, large in- put data, using to peer-to-peer (P2P) protocols and Content Distribution Networks (CDN). We make a step further and propose a generic, yet efficient data storage which enables the use of Desktop Grids for applications with high output data re- quirements, where the access grain and the access patterns may be random. Our solution builds on a blob management service enabling a large number of con- current clients to efficiently read/write and append huge data that are fragmented and distributed at a large scale. Scalability under heavy concurrency is achieved thanks to an original metadata scheme using a distributed segment tree built on top of a Distributed Hash Table (DHT). The proposed approach has been imple- mented and its benefits have successfully been demonstrated within our BlobSeer prototype on the Grid'5000 testbed