Graphs whose indecomposability graph is 2-covered

Given a graph $G=(V,E)$, a subset $X$ of $V$ is an interval of $G$ provided that for any $a, b\in X$ and $x\in V \setminus X$, $\{a,x\}\in E$ if and only if $\{b,x\}\in E$. For example, $\emptyset$, $\{x\}(x\in V)$ and $V$ are intervals of $G$, called trivial intervals. A graph whose intervals are trivial is indecomposable; otherwise, it is decomposable. According to Ille, the indecomposability graph of an undirected indecomposable graph $G$ is the graph $\mathbb I(G)$ whose vertices are those of $G$ and edges are the unordered pairs of distinct vertices $\{x,y\}$ such that the induced subgraph $G[V \setminus \{x,y\}]$ is indecomposable. We characterize the indecomposable graphs $G$ whose $\mathbb I(G)$ admits a vertex cover of size 2.Comment: 31 pages, 5 figure

Recognition and translation Arabic-French of Named Entities: case of the Sport places

The recognition of Arabic Named Entities (NE) is a problem in different domains of Natural Language Processing (NLP) like automatic translation. Indeed, NE translation allows the access to multilingual in-formation. This translation doesn't always lead to expected result especially when NE contains a person name. For this reason and in order to ameliorate translation, we can transliterate some part of NE. In this context, we propose a method that integrates translation and transliteration together. We used the linguis-tic NooJ platform that is based on local grammars and transducers. In this paper, we focus on sport domain. We will firstly suggest a refinement of the typological model presented at the MUC Conferences we will describe the integration of an Arabic transliteration module into translation system. Finally, we will detail our method and give the results of the evaluation

A Time-Triggered Constraint-Based Calculus for Avionic Systems

The Integrated Modular Avionics (IMA) architec- ture and the Time-Triggered Ethernet (TTEthernet) network have emerged as the key components of a typical architecture model for recent civil aircrafts. We propose a real-time constraint-based calculus targeted at the analysis of such concepts of avionic embedded systems. We show our framework at work on the modelisation of both the (IMA) architecture and the TTEthernet network, illustrating their behavior by the well-known Flight Management System (FMS)

MINERALOGY AND SULFUR ISOTOPE GEOCHEMISTRY OF THE APEX AND BONANZA PROSPECTS AT THE GOLDEN SUNLIGHT MINE, MONTANA

The Golden Sunlight mine, located 50 km to the east of the famous Butte porphyry/lode deposits, is the largest gold mine in Montana, and has produced over 3 million ounces of gold in its 35+ year history. Most of this gold has come from the Mineral Hill breccia pipe (MHBP), a west dipping, cylindrical body of brecciated latite and country rock fragments of the Precambrian LaHood and Greyson Formations. The breccia pipe is late Cretaceous in age (84±18 Ma, DeWitt et al., 1986), is silicified, pyrite-rich, and is mineralized with gold, silver, and minor base metals. Because the MHBP has largely been mined out, the present owners of the mine, Barrick Gold, have been exploring new prospects called Apex and Bonanza to the north of the main MHBP ore body. The Apex deposit exists near the unconformable contact between the Proterozoic Greyson Fm. and the overlying Cambrian Flathead Fm. Both sedimentary units are mineralized, although exploration has focused more on structures in the Greyson formation. The Bonanza prospect is exploring the contact between latite porphyry and the Greyson Formation. The purpose of the present study is to examine the mineralogy and stable isotope geochemistry of Apex and Bonanza to see how it relates to the MHBP. Reflected and transmitted light microscopy and SEM-EDS analyses of polished core samples from Apex and Bonanza reveal a complex paragenesis of ore and gangue minerals that is similar to that described by previous workers for MHBP. Pyrite is the dominant sulfide, accompanied by common sulfides such as galena, sphalerite, chalcopyrite, bornite, and tetrahedrite-tennantite, as well as less common phases such as pearceite (Cu(Ag,Cu)6Ag9As2S11), tetradymite (Bi2Te2S), aikinite (CuPbBiS3), goldfieldite (Cu10Te4S13), and electrum (Au-Ag alloy). Gangue minerals include quartz, barite, anhydrite, adularia, dolomite, siderite, sericite, rutile, althausite and magnetite. Analyses of drill core with a Terraspec Halo SWIR device reveal that illite, muscovite and kaolinite are the dominant alteration minerals, with several detections of the NH4-rich K-feldspar, buddingtonite. The S-isotope composition of pyrite and molybdenite in veins from the North Pit, Bonanza and Apex deposits overlap with pyrite from the MHBP (as determined by previous workers). In the deposits, there is a cluster of δ34S values in the range of -10 to -5 ‰, with a tail to more positive values \u3e 0 ‰. The heavier S appears to be associated with sedimentary pyrite in the Precambrian Belt sediments whereas the lighter S is of hydrothermal origin. The fact that the mineralogy and S-isotopic compositions at Apex, Bonanza, and MHBP are similar implies that the deposits formed in the same ore-forming event. The light S-isotope composition of sulfides at Apex and MHBP may have been caused by separate processes: 1) assimilation of isotopically light sulfide at a deeper crustal level by ascending magmas and/or 2) isotopic fractionation between sulfide and sulfate in an oxidized (SO2-stable) environment

Public Debt and Private Investment in Subsaharan Africa

The purpose of this study is to analyze the effect of public debt on private investment in Sub-Saharan Africa SSA To this end we proceed with the econometric estimation of the data for a panel of 43 SSA countries over the period 2000- 2018 All of this data comes from the World Bank IDS WDI WGI and the IMF WEO In order to achieve robust results three estimation methods are used the Ordinary Least Squares OLS method the Ordinary Doubles Least Squares ODLS method and the Quantile regression method All other things being equal the results show that public debt reduces private investment because of credit rationing and higher taxes to honor debt services However we find that the debt from China is positively correlated with private investment Therefore to reconcile public debt and private investment SSA countries need to implement appropriate policies that will ensure that public debt is used optimally to further stimulate private investment Indeed SSA countries must encourage and monitor the channeling of financial resources to productive activities likely to strengthen private investment In addition African leaders must implement policies that reduce the interest rate and in turn the crowding out effect of the private sector Public-private partnerships should also be encourage

Querying heterogeneous data in NoSQL document stores

La problématique de cette thèse porte sur l'interrogation de données hétérogènes dans les systèmes de stockage "not-only SQL" (noSQL) orientés documents. Ces derniers ont connu un important développement ces dernières années en raison de leur capacité à gérer de manière flexible et efficace d'importantes masses de documents. Ils reposent sur le principe "schema-less" consistant à ne plus considérer un schéma unique pour un ensemble de données, appelé collection de documents. Cette flexibilité dans la structuration des données complexifie l'interrogation pour les utilisateurs qui doivent connaître l'ensemble des différents schémas des données manipulées lors de l'écriture de requêtes. Les travaux développés dans cette thèse sont menés dans le cadre du projet neoCampus. Ils se focalisent sur l'interrogation de documents structurellement hétérogènes, en particulier sur le problème de schémas variables. Nous proposons la construction d'un dictionnaire de données qui permet de retrouver tous les schémas des documents. Chaque clef, entrée du dictionnaire, correspond à un chemin absolu ou partiel existant dans au moins un document de la collection. Cette clef est associée aux différents chemins absolus correspondants dans l'ensemble de la collection de documents. Le dictionnaire est alors exploité pour réécrire de manière automatique et transparente les requêtes des utilisateurs. Les requêtes utilisateurs sont établies sur la base des clés du dictionnaire (chemins partiels ou absolus) et sont automatiquement réécrites en exploitant le dictionnaire afin de prendre en compte l'ensemble des chemins absolus existants dans les documents de la collection. Dans cette thèse, nous menons une étude de l'état de l'art des travaux s'attachant à résoudre l'interrogation de documents structurellement hétérogènes, et nous en proposons une classification. Ensuite, nous comparons ces travaux en fonction de critères qui permettent de positionner et différencier notre contribution. Nous définissions formellement les concepts classiques liés aux systèmes orientés documents (document, collection, etc), puis nous étendons cette formalisation par des concepts supplémentaires : chemins absolus et partiels, schémas de document, dictionnaire. Pour la manipulation et l'interrogation des documents, nous définissons un noyau algébrique minimal fermé composé de cinq opérateurs : sélection, projection, des-imbrication (unnest), agrégation et jointure (left-join). Nous définissons chaque opérateur et expliquons son évaluation par un moteur de requête classique. Ensuite, nous établissons la réécriture de chacun des opérateurs à partir du dictionnaire. Nous définissons le processus de réécriture des requêtes utilisateurs qui produit une requête évaluable par un moteur de requête classique en conservant la logique des opérateurs classiques (chemins inexistants, valeurs nulles). Nous montrons comment la réécriture d'une requête initialement construite avec des chemins partiels et/ou absolus permet de résoudre le problème d'hétérogénéité structurelle des documents. Enfin, nous menons des expérimentations afin de valider les concepts formels que nous introduisons tout au long de cette thèse. Nous évaluons la construction et la maintenance du dictionnaire en changeant la configuration en termes de nombre de structures par collection étudiée et de taille de collection. Puis, nous évaluons le moteur de réécriture de requêtes en le comparant à une évaluation de requête dans un contexte sans hétérogénéité structurelle puis dans un contexte de multi-requêtes. Toutes nos expérimentations ont été menées sur des collection synthétiques avec plusieurs niveaux d'imbrications, différents nombres de structure par collection, et différentes tailles de collections. Récemment, nous avons intégré notre contribution dans le projet neOCampus afin de gérer l'hétérogénéité lors de l'interrogation des données de capteurs implantés dans le campus de l'université Toulouse III-Paul Sabatier.This thesis discusses the problems related to querying heterogeneous data in document-oriented systems. Document-oriented "not-only SQL" (noSQL) storage systems have undergone significant development in recent years due to their ability to manage large amounts of documents in a flexible and efficient manner. These systems rely on the "schema-less" concept where no there is no requirement to consider a single schema for a set of data, called a collection of documents. This flexibility in data structures makes the query formulation more complex and users need to know all the different schemas of the data manipulated during the query formulation. The work developed in this thesis subscribes into the frame of neOCampus project. It focuses on issues in the manipulation and the querying of structurally heterogeneous document collections, mainly the problem of variable schemas. We propose the construction of a dictionary of data that makes it possible to find all the schemas of the documents. Each key, a dictionary entry, corresponds to an absolute or partial path existing in at least one document of the collection. This key is associated to all the corresponding absolute paths throughout the collection of heterogeneous documents. The dictionary is then exploited to automatically and transparently reformulate queries from users. The user queries are formulated using the dictionary keys (partial or absolute paths) and are automatically reformulated using the dictionary to consider all the existing paths in all documents in the collection. In this thesis, we conduct a state-of-the-art survey of the work related to solving the problem of querying data of heterogeneous structures, and we propose a classification. Then, we compare these works according to criteria that make it possible to position our contribution. We formally define the classical concepts related to document-oriented systems (document, collection, etc). Then, we extend this formalisation with additional concepts: absolute and partial paths, document schemas, dictionary. For manipulating and querying heterogeneous documents, we define a closed minimal algebraic kernel composed of five operators: selection, projection, unnest, aggregation and join (left join). We define each operator and explain its classical evaluation by the native document querying engine. Then we establish the reformulation rules of each of these operators based on the use of the dictionary. We define the process of reformulating user queries that produces a query that can be evaluated by most document querying engines while keeping the logic of the classical operators (misleading paths, null values). We show how the reformulation of a query initially constructed with partial and/or absolute paths makes it possible to solve the problem of structural heterogeneity of documents. Finally, we conduct experiments to validate the formal concepts that we introduce throughout this thesis. We evaluate the construction and maintenance of the dictionary by changing the configuration in terms of number of structures per collection studied and collection size. Then, we evaluate the query reformulation engine by comparing it to a query evaluation in a context without structural heterogeneity and then in a context of executing multiple queries. All our experiments were conducted on synthetic collections with several levels of nesting, different numbers of structures per collection, and on varying collection sizes. Recently, we deployed our contributions in the neOCampus project to query heterogeneous sensors data installed at different classrooms and the library at the campus of the university of Toulouse III-Paul Sabatier

Does multinationals socially responsible in Sub-Sahara Africa? Case of AREVA in Niger

Societal actions in terms of CSR of the French nuclear group in Niger contrast with stakeholders charges against him (pollution, degradation of the environment, groundwater contamination, etc.) and certain realities observed on the field (armed conflict, poverty, social inequalities, disintegration of the local economy). This paper proposes to shed light on the issues and controversies related to the practice of CSR in Africa in general, those related to Areva group in Niger in particular. The absence of regulatory frameworks calls for public regulation in the practice of CSR. Indeed because of conflicts between Areva and its stakeholders, public regulation could help include more actions of the group in the process of socially responsible industrial development

Optical Extraction Efficiency for External Cavity Quantum Cascade Lasers

In this paper, we present a simple method for calculation of optical extraction efficiency of mid-infrared quantum cascade laser coupled to external cavity. The approach is based on the three-level rate equation model describing the variation of the electron number in the states and the photon number present within the Fabry-Perot quantum cascade laser and the external cavity. The system shares the same active region and includes the dependence of the loss on external cavity parameters. We find in particular that the power coupled out through the external mirror varies linearly with current injection and depends strongly on the external cavity reflectivity. Moreover, a considerable increase in the threshold current of external cavity occurs when decreasing the values of the external cavity reflectivity and the slope efficiency decreases with decreasing external cavity reflectivity. We also derive an analytical formula for the optical extraction efficiency of external cavity and analyze the simultaneous effects of the current injection and the external cavity reflectivity on it. Results show that at laser threshold, the optical extraction efficiency is zero and it rises as the current injection increases. For high current injection, extraction efficiency of up to 11 % at Rext = 10 % can be attained. In addition, the equations allowing the determination of the optimum reflectance of external cavity and the maximum optical extraction efficiency are also derived within the premises of our model in the general case