Towards trusted volunteer grid environments

Intensive experiences show and confirm that grid environments can be considered as the most promising way to solve several kinds of problems relating either to cooperative work especially where involved collaborators are dispersed geographically or to some very greedy applications which require enough power of computing or/and storage. Such environments can be classified into two categories; first, dedicated grids where the federated computers are solely devoted to a specific work through its end. Second, Volunteer grids where federated computers are not completely devoted to a specific work but instead they can be randomly and intermittently used, at the same time, for any other purpose or they can be connected or disconnected at will by their owners without any prior notification. Each category of grids includes surely several advantages and disadvantages; nevertheless, we think that volunteer grids are very promising and more convenient especially to build a general multipurpose distributed scalable environment. Unfortunately, the big challenge of such environments is, however, security and trust. Indeed, owing to the fact that every federated computer in such an environment can randomly be used at the same time by several users or can be disconnected suddenly, several security problems will automatically arise. In this paper, we propose a novel solution based on identity federation, agent technology and the dynamic enforcement of access control policies that lead to the design and implementation of trusted volunteer grid environments.Comment: 9 Pages, IJCNC Journal 201

GeomRDF: A Geodata Converter with a Fine-Grained Structured Representation of Geometry in the Web

In recent years, with the advent of the web of data, a growing number of national mapping agencies tend to publish their geospatial data as Linked Data. However, differences between traditional GIS data models and Linked Data model can make the publication process more complicated. Besides, it may require, to be done, the setting of several parameters and some expertise in the semantic web technologies. In addition, the use of standards like GeoSPARQL (or ad hoc predicates) is mandatory to perform spatial queries on published geospatial data. In this paper, we present GeomRDF, a tool that helps users to convert spatial data from traditional GIS formats to RDF model easily. It generates geometries represented as GeoSPARQL WKT literal but also as structured geometries that can be exploited by using only the RDF query language, SPARQL. GeomRDF was implemented as a module in the RDF publication platform Datalift. A validation of GeomRDF has been realized against the French administrative units dataset (provided by IGN France).Comment: 12 pages, 2 figures, the 1st International Workshop on Geospatial Linked Data (GeoLD 2014) - SEMANTiCS 201

The 'Ulama' of Iran in the 19th century hagiographical literature

This study is concerned with the biographies of the Shi'i 'ulama'in Iran during the 19th century, who played a major role in the emergence of the Shi'i hierocracy as religious executors of state affairs. Chapter I: provides an overview of the relations between state and 'Ulamd' in the Safavid period and traces the development of usuli doctrine as the dominant school of ShT'i fiqh (jurisprudence). Chapters II, III and IV: focus on the lives and works of three groups of the mujtahids divided according to their generation. The first generation comprises the students of Bihbihani, who were concerned primarly with the consolidation of the Usuli school. The second generation was responsible for the formulation of the concept of wildyat al-faqih. Finally the third generation emphasised the concept of the role of the marja' al taqlid, thus paving the way for the mujtahids to intervene in affairs of state

Direct determination of crop evapotranspiration in the Arkansas Valley with a weighing lysimeter

January 2011.Includes bibliographical references

OVERCONFIDENCE BIAS: EXPLANATION OF MARKET ANOMALIES FRENCH MARKET CASE

In this study, we test whether the overconfidence bias explains several stylized market anomalous, including a short-term continuation (momentum), a long-term reversal in stock returns, high levels of trading volume and excessive volatility. Using data of French stocks market, we find empirical evidence in support of overconfidence hypothesis. First, based on a restricted VAR framework, we show that overconfident investors overreact to private information and underreact to public information. Second, by performing Granger-causality tests of stock returns and trading volume, we find that overconfident investors trade more aggressively in periods subsequent to market gains. Third, based on a two GARCH specifications, we show that self attribution bias, conditioned by right forecasts, increases investors overconfidence and trading volume. Fourth, the analysis of the relation between return volatility and trading volume shows that the excessive trading of overconfident investors makes a contribution to the observed excessive volatility.Overconfidence, Behavioural finance, Over (under) reaction, Trading volume, Volatility

La formation du pluriel en arabe marocain: Approche fonctionnelle

Plural Training in Moroccan Arab Functional Approach This article deals with the methods of plural in Moroccan dialect with a functional approach based on the functional grammar as mentioned by DIK through production, rules, regularity, speakers and types of plural for the absent and external

The Effect of Free Cash Flow on the Relationship Between Managerial Entrenchment and Debt: Evidence From French Firms

At first, this paper examines the association between managerial entrenchment and corporate leverage in French case. Then, the effect of free cash flow in this relationship is investigated. Using a sample of 98 listed French companies in Euronext Paris from 2000 to 2014, it was found that CEO entrenchment is related positively to debt before financial crisis and negatively after crisis. Also, free cash flow moderates the relationship between CEO entrenchment and corporate debt before crisis. Keywords: CEO Entrenchment- Debt- Free Cash-Flow- moderator variabl

Sentiment Strategy

This study tests if investor’s sentiment risk is valued by the stock markets. We form portfolios based upon the stock returns’ exposure to sentiment. Our results show that, globally, the stocks most influenced by the sentiment factor earn higher returns than the stocks less impacted by the sentiment factor. The strategy consisting of buying portfolios of stocks with greater exposure to sentiment and selling those with the lower exposure generates a statistically significant raw profit. Exploring the sources of profit, we find that neither the traditional risk factors nor the momentum factor (conventional risk) can account for the profit. However, the addition of the sentiment risk premium contributes to better explain the profit. Keywords: Investor sentiment, Stock returns, Noise trader risk