On Deterministic Sketching and Streaming for Sparse Recovery and Norm Estimation

We study classic streaming and sparse recovery problems using deterministic linear sketches, including $\ell_1/\ell_1$ and $\ell_{\infty}/\ell_1$ sparse recovery problems (the latter also being known as ℓ1ℓ1-heavy hitters), norm estimation, and approximate inner product. We focus on devising a fixed matrix $A \epsilon \mathbb{R}^{m \times n}$ and a deterministic recovery/estimation procedure which work for all possible input vectors simultaneously. Our results improve upon existing work, the following being our main contributions: • A proof that $\ell_{\infty}/\ell_1$ sparse recovery and inner product estimation are equivalent, and that incoherent matrices can be used to solve both problems. Our upper bound for the number of measurements is $m=O(\varepsilon^{-2}min\{log n,(log n/log(1/\varepsilon))^2\})$. We can also obtain fast sketching and recovery algorithms by making use of the Fast Johnson–Lindenstrauss transform. Both our running times and number of measurements improve upon previous work. We can also obtain better error guarantees than previous work in terms of a smaller tail of the input vector. • A new lower bound for the number of linear measurements required to solve $\ell_1/\ell_1$ sparse recovery. We show $\Omega(k/\varepsilon^2+k log(n/k)/\varepsilon)$ measurements are required to recover an x′ with $‖x-x′‖_1\leq(1+\varepsilon)‖x_{tail(k)}‖_1$, where $x_{tail(k)}$ is x projected onto all but its largest k coordinates in magnitude. • A tight bound of $m=\theta(\varepsilon^{-2}log(\varepsilon^2n))$ on the number of measurements required to solve deterministic norm estimation, i.e., to recover $‖x‖_2\pm\varepsilon‖x‖_1$. For all the problems we study, tight bounds are already known for the randomized complexity from previous work, except in the case of $\ell_1/\ell_1$ sparse recovery, where a nearly tight bound is known. Our work thus aims to study the deterministic complexities of these problems. We remark that some of the matrices used in our algorithms, although known to exist, currently are not yet explicit in the sense that deterministic polynomial time constructions are not yet known, although in all cases polynomial time Monte Carlo algorithms are known.Engineering and Applied Science

Une approche symbolique pour la vérification et le test des chorégraphies de services

L'ingénierie orientée services est un nouveau paradigme pour développer des logiciels distribués et collaboratifs. Un tel logiciel se compose de plusieurs entités, appelés services, chacun d'entre eux étant par exemple une application Web, un service Web, ou même un humain. Les services peuvent être développés indépendamment et sont composés pour atteindre quelques exigences. Les chorégraphies de service définissent ces exigences avec une perspective globale, basée sur les interactions entre des participants qui sont implémentés en tant que services. Cette thèse vise à formaliser des problèmes et tente d'élaborer un environnement intégré avec lequel les chorégraphies de services peuvent être développés correctement pour les deux types d'approches de développement: l'approche descendante et l'approche ascendante. Elle consiste à analyser la relation entre une spécification de chorégraphie et une implémentation de la chorégraphie au niveau du modèle et aussi au niveau de l'implémentation réelle. Particulièrement, il s'agit de la composition/décomposition des services, la vérification, et le test de l'implémentation de chorégraphie. Le premier point-clé de notre environnement intégré est de représenter le passage de valeurs entre les services en utilisant la technique symbolique et un solveur SMT. Cette technique nous permet de réduire les faux négatifs et de contourner le problème d'explosion combinatoire de l'espace d'états, ces problèmes sont durs à l'abstraction et à l'énumération des valeurs pour les approches existantes basées données. Le second point-clé est le test passif boîte noire de l'implémentation de chorégraphie. Il ne nécessite pas d'accéder au code source, ni de rendre indisponible l'implémentation pendant le processus de test. Notre environnement intégré est mis en œuvre dans nos outils qui sont disponibles en téléchargement ou à utiliser en ligne à l adresse http://schora.lri.fr.Service-oriented engineering is an emerging software development paradigm for distributed collaborative applications. Such an application is made up of several entities abstracted as services, each of them being for example a Web application, a Web service, or even a human. The services can be developed independently and are composed to achieve common requirements through interactions among them. Service choreographies define such requirements from a global perspective, based on interactions among a set of participants. This thesis aims to formalize the problems and attempts to develop a framework by which service choreographies can be developed correctly for both top-down and bottom-up approaches. It consists in analyzing the relation between a choreography specification and a choreography implementation at both model level and real implementation level. Particularly, it concerns the composition/decomposition service design, the verification, and the testing of choreography implementation. The first key point of our framework is to support value-passing among services by using symbolic technique and SMT solver. It overcomes false negatives or state space explosion issues due by abstracting or limiting the data domain of value-passing in existing approaches. The second key point is the black-box passive testing of choreography implementation. It does not require neither to access to source codes nor to make the implementation unavailable during the testing process. Our framework is fully implemented in our toolchains, which can be downloaded or used online at address: http://schora.lri.fr.PARIS11-SCD-Bib. électronique (914719901) / SudocSudocFranceF

Search for Spatial Correlations of Neutrinos with Ultra-high-energy Cosmic Rays

For several decades, the origin of ultra-high-energy cosmic rays (UHECRs) has been an unsolved question of high-energy astrophysics. One approach for solving this puzzle is to correlate UHECRs with high-energy neutrinos, since neutrinos are a direct probe of hadronic interactions of cosmic rays and are not deflected by magnetic fields. In this paper, we present three different approaches for correlating the arrival directions of neutrinos with the arrival directions of UHECRs. The neutrino data are provided by the IceCube Neutrino Observatory and ANTARES, while the UHECR data with energies above ∼50 EeV are provided by the Pierre Auger Observatory and the Telescope Array. All experiments provide increased statistics and improved reconstructions with respect to our previous results reported in 2015. The first analysis uses a high-statistics neutrino sample optimized for point-source searches to search for excesses of neutrino clustering in the vicinity of UHECR directions. The second analysis searches for an excess of UHECRs in the direction of the highest-energy neutrinos. The third analysis searches for an excess of pairs of UHECRs and highest-energy neutrinos on different angular scales. None of the analyses have found a significant excess, and previously reported overfluctuations are reduced in significance. Based on these results, we further constrain the neutrino flux spatially correlated with UHECRs

La situation de la femme dans la société du Sud-Vietnam vue à travers la production littéraire des auteurs du terroir de 1858 à 1945 (essai de construction d'une anthropologie culturelle et historique de la Vietnamienne du Sud)

AIX-MARSEILLE1-BU Lettres (130012101) / SudocSudocFranceF

À l'origine de l'anthropologie au Vietnam (recherches sur les auteurs de la première génération)

AIX-MARSEILLE1-BU Lettres (130012101) / SudocSudocFranceF

L'enseignement du français à Ho Chi Minh Ville depuis 1975

Notre étude focalisée sur HCMV et sa région se veut d'abord une contribution à l'évaluation de la réintroduction du français au Vietnam. L'intervention de l'Agence universitaire de la francophonie (AUF), la mise en place de nouvelles filières et de classes bilingues à partir de 1992 ont profondément changé la situation du français au Vietnam. Les thématiques nouvelles des manuels, les méthodes d'enseignement changent également cette situation de manière irréversible.This study, which concentrates on HCMV and its region, is first and foremost a contribution to the evaluation of the reintroduction of french to Vietnam. Since 1992 the work carried out by the Auf, as well as the creation of new university programmes and bilingual classes has profoundly changed the place of french linguage in Vietnam. The adoption of new approaches and teaching methods have likewise changed this situation definitivelyTOURS-BU Lettres (372612102) / SudocSudocFranceF

On approximating matrix norms in data streams

This paper presents a systematic study of the space complexity of estimating the Schatten p-norms of an n×n matrix in the turnstile streaming model. Both kinds of space complexities, bit complexity and sketching dimension, are considered. Furthermore, two sketching models, general linear sketching and bilinear sketching, are considered. When p is not an even integer, we show that any one-pass algorithm with constant success probability requires near-linear space in terms of bits. This lower bound holds even for sparse matrices, i.e., matrices with O(1) nonzero entries per row and per column. However, when p is an even integer, we give for sparse matrices an upper bound which, up to logarithmic factors, is the same as estimating the pth moment of an n-dimensional vector. These results considerably strengthen lower bounds in previous work for arbitrary (not necessarily sparse) matrices. Similar near-linear lower bounds are obtained for Ky Fan norms, SVD entropy, eigenvalue shrinkers, and M-estimators, many of which could have been solvable in logarithmic space prior to this work. The results for general linear sketches give separations in the sketching complexity of Schatten p-norms with the corresponding vector p-norms, and rule out a table-lookup nearest-neighbor search for p = 1, making progress on a question of Andoni. The results for bilinear sketches are tight for the rank problem and nearly tight for p ≥ 2; the latter is the first general subquadratic upper bound for sketching the Schatten norms.Ministry of Education (MOE)Published versionThe first author was partially supported by Singapore Ministry of Education (AcRF)Tier 2 grant MOE2018-T2-1-013. The second author was partially supported by NSF CAREER award 1750716. The third author was partially supported by National Science Foundation grant CCF-1815840

Étude comparative des interactions verbales dans les consultations médicales en France et au Vietnam (étude de cas, la médecine généraliste de Hué)

L'étude comparative des interactions verbales dans les consultations médicales en France et au Vietnam permet de mettre en évidence des disparités linguistiques, socio-culturelles qui régissent les comportements langagiers des interlocuteurs, et qui se situent à plusieurs niveaux de la langue : les termes d'adresse, les actes de langage, etc. Ces différences constituent de nombreuses difficultés pour les médecins vietnamiens lorsque ceux-ci sont en contact avec les patients français et/ou francophones. Elles influencent la communication et structurent la situation d'échanges. Comment coopèrent les deux interlocuteurs dans la communication ? Quelles stratégies développent-ils (stratégies d'évitement de difficultés et/ou stratégies d'affrontement de difficultés) ? Quels procédés ont-ils mis en oeuvre pour parvenir à une compréhension mutuelle (procédés d'ordre linguistique et/ou procédés d'ordre interactionnel) ? C'est sur ces questions qu'est centré notre présent travail de recherchesROUEN-BU Lettres (764512101) / SudocSudocFranceF