RDF Modelling and SPARQL Processing of SQL Abstract Syntax Trees

International audienceMost enterprise systems rely on relational databases, and therefore SQL queries, to populate dynamic documents such as business intelligence reports, dashboards or spreadsheets. These queries represent metadata about the documents, thus they can feed information retrieval systems such as recommender systems or search engines. In this paper we propose to automatically annotate documents with structured representations of their SQL queries expressed with RDF graphs. We show that SPARQL is a natural language to query these SQL queries, i.e. to perform meta-querying, and discuss challenges that arise from this approach

Développement et implémentation parallèle de méthodes d'interaction de configurations sélectionnées

Cette thèse, ayant pour thème les algorithmes de la chimie quantique, s'inscrit dans le cade du changement de paradigme observé depuis une douzaines d'années, dans lequel les méthodes de calcul séquentielles se doivent d'être progressivement remplacées par des méthodes parallèles. En effet, l'augmentation de la fréquences des processeurs se heurtant à des barrières physiques difficilement franchissables, l'augmentation de la puissance de calcul se fait par l'augmentation du nombre d'unités de calcul. Toutefois, là où une augmentation de la fréquence conduisait mécaniquement à une exécution plus rapide d'un code, l'augmentation du nombre de cœurs peut se heurter à des barrières algorithmiques, qui peuvent nécessiter une adaptation ou un changement d'algorithme. Parmi les méthodes développées afin de contourner ce problème, on trouve en particulier celles de type Monte-Carlo (stochastiques), qui sont intrinsèquement "embarrassingly parallel", c'est à dire qu'elles sont par construction constituées d'une multitudes de tâches indépendantes, et de ce fait particulièrement adaptées aux architectures massivement parallèles. Elles ont également l'avantage, dans de nombreux cas, d'être capables de produire un résultat approché pour une fraction du coût calculatoire de l'équivalent déterministe exacte. Lors de cette thèse, des implémentations massivement parallèles de certains algorithmes déterministes de chimie quantique ont été réalisées. Il s'agit des algorithmes suivants : CIPSI, diagonalisation de Davidson, calcul de la perturbation au second ordre, shifted-Bk, et Coupled Cluster Multi Références. Pour certains, une composante stochastique a été introduite en vue d'améliorer leur efficacité. Toutes ces méthodes ont été implémentées sur un modèle de tâches distribuées en TCP, où un processus central distribue des tâches par le réseau et collecte les résultats. En d'autres termes, des nœuds esclaves peuvent être ajoutés au cours du calcul depuis n'importe quelle machine accessible depuis internet. L'efficacité parallèle des algorithmes implémentés dans cette thèse a été étudiée, et le programme a pu donner lieu à de nombreuses applications, notamment pour permettre d'obtenir des énergies de références pour des systèmes moléculaires difficiles.This thesis, whose topic is quantum chemistry algorithms, is made in the context of the change in paradigm that has been going on for the last decade, in which the usual sequential algorithms are progressively replaced by parallel equivalents. Indeed, the increase in processors' frequency is challenged by physical barriers, so increase in computational power is achieved through increasing the number of cores. However, where an increase of frequency mechanically leads to a faster execution of a code, an increase in number of cores may be challenged by algorithmic barriers, which may require adapting of even changing the algorithm. Among methods developed to circumvent this issue, we find in particular Monte-Carlo methods (stochastic methods), which are intrinsically "embarrassingly parallel", meaning they are by design composed of a large number of independent tasks, and thus, particularly well-adapted to massively parallel architectures. In addition, they often are able to yield an approximate result for just a fraction of the cost of the equivalent deterministic, exact computation. During this thesis, massively parallel implementations of some deterministic quantum chemistry algorithms were realized. Those methods are: CIPSI, Davidson diagonalization, computation of second-order perturbation, shifted-Bk, Multi-Reference Coupled-Cluster. For some of these, a stochastic aspect was introduced in order to improve their efficiency. All of them were implemented on a distributed task model, with a central process distributing tasks and collecting results. In other words, slave nodes can be added during the computation from any location reachable through Internet. The efficiency for the implemented algorithms has been studied, and the code could give way to numerous applications, in particular to obtain reference energies for difficult molecular systems

Activity-Based Scheduling of IT Changes

ITIL, change management, scheduling Change management is a disciplined process for introducing required changes onto the IT environment, with the underlying objective of minimizing disruptions to the business services as a result of performing IT changes. Currently, one of the most pressing problems in change management is the scheduling and planning of changes. Building on an earlier mathematical formulation of the change scheduling problem, in this paper we take the formulation of the problem one step further by breaking down the changes into the activities that compose them. We illustrate the theoretical viability of the approach, discuss the limit of its applicability to real life scenarios, describe heuristic techniques that promise to bridge the scalability gap and provide experimental validation for them

Semantic Web Support for the Business-to-Business E-Commerce Lifecycle

... widespread, standardisation of ontologies, message content and message protocols will be necessary. In this paper, we present a lifecycle of a business-to-business e-commerce interaction, and show how the Semantic Web can support a service description language that can be used throughout this lifecycle. By using DAML+OIL, we develop a service description language sufficiently expressive and flexible to be used not only in advertisements, but also in matchmaking queries, negotiation proposals and agreements. We also identify which operations must be carried out on this description language if the B2B lifecycle is to be fully supported. We do not propose specific standard protocols, but instead argue that our operators are able to support a wide variety of interaction protocols, and so will be fundamental irrespective of which protocols are finally adopted

A Semantic Web Approach to Service Description for Matchmaking of Services

semantic web, e-commerce, matchmaking services, automated negotiation, electronic marketplaces, ontology Matchmaking is an important aspect of e-commerce interactions. Advanced matchmaking services require rich and flexible metadata that are not supported by currently available industry standard frameworks for e-commerce such as UDDI and ebXML. The semantic web initiative at W3C is gaining momentum and generating technologies and tools that might help bridge the gap between the current standard solutions and the requirement for advanced matchmaking services. In this paper we examine the problem of matchmaking, highlighting the features that a matchmaking service should exhibit and deriving requirements on metadata for description of services from a matchmaking point of view. We then assess a couple of standard frameworks for e-commerce against these requirements. Finally, we report on our experience of developing a semantic web based matchmaking prototype. In particular, we present our views on usefulness, adequacy, maturity and tool support of semantic web related technologies such as RDF and DAML

A Model for Assisting Business Users along Analytical Processes

Abstract. User-centric business intelligence aims at empowering analysts who interact with complex tools, by allowing them to perform accurate data manipulations and analysis without necessarily requiring IT expertise and knowledge of underlying data specifications. Recommender systems contribute to easing their tasks but most of them operate inside walled gardens and cannot assist properly the user throughout his BI workflow. In this paper we introduce a lightweight vocabulary intended to capture fragments of analytical workflows as multidimensional data transformations, within a Semantic Web framework. We utilize this model for calculating content-based recommendations

Lifting XML Schema to OWL

Abstract. The Semantic Web will allow software agents to understand and reason about data provided by Web applications. Unfortunately, formal ontologies, needed to express data semantics, are often not readily available. However, common data schemas can help to create ontologies. We propose mappings from XML Schema to OWL as well as XML to RDF and show how web engineering can benefit from the gained expressiveness as well as the use of inference services.

SLA, SLA State

In today’s business environment, change must be seen not as an exception but as the normal state of affairs. With its Darwin Architecture, HP addresses business agility, defined as the ability of one enterprise to respond to and anticipate business changes with speed and flexibility while meeting cost, quality of service and risk management objectives. One of the requirements that agility imposes on an enterprise is that their business groups and IT (Information Technology) groups must come together to create an adaptive enterprise in which business needs drive IT response, and business and IT changes are synchronized in real time. When projected onto the space of IT management, this requirement is translated into the need of managing IT in light of the business objectives of an enterprise. We introduce Management by Contract (MbC) as a paradigm to address this need. In this work we present the basic ideas of Management by Contract and we give a motivating scenario describing a hypothetical company that hosts IT infrastructure. We then describe the architecture of our prototype system, report on some experimental results and sketch the future directions of our research