Benefits of InterSite Pre-Processing and Clustering Methods in E-Commerce Domain

This paper presents our preprocessing and clustering analysis on the clickstream dataset proposed for the ECMLPKDD 2005 Discovery Challenge. The main contributions of this article are double. First, after presenting the clickstream dataset, we show how we build a rich data warehouse based an advanced preprocesing. We take into account the intersite aspects in the given ecommerce domain, which offers an interesting data structuration. A preliminary statistical analysis based on time period clickstreams is given, emphasing the importance of intersite user visits in such a context. Secondly, we describe our crossed-clustering method which is applied on data generated from our data warehouse. Our preliminary results are interesting and promising illustrating the benefits of our WUM methods, even if more investigations are needed on the same dataset

Seasonal modes of dryness and wetness variability over Europe and their connections with large scale atmospheric circulation and global sea surface temperature

The relationship between the seasonal modes of interannual variability of a multiscalar drought index over Europe and the large-scale atmospheric circulation and sea surface temperature (SST) anomaly fields is investigated through statistical analysis of observed and reanalysis data. It is shown that the seasonal modes of dryness and wetness variability over Europe and their relationship with the large-scale atmospheric circulation and global SST anomaly fields differ from one season to another. During winter, the dominant modes of dryness and wetness variability are influenced by the Arctic Oscillation (AO)/North Atlantic Oscillation (NAO), the Scandinavian pattern, the East Atlantic pattern and the East Atlantic/Western Russia pattern. The spring dryness/wetness modes are influenced mainly by the AO, Polar/Eurasian patterns and the Atlantic Multidecadal Oscillation conditions. The phases (positive or negative) and the superposition of these large scale variability modes play a significant role in modulating the drought conditions over Europe. During summer, the atmospheric blocking is one of the main drivers of dryness and wetness conditions, while during autumn dryness/wetness conditions variability can be related to the NAO or with a wave train like pattern in the geopotential height at 850mb, which develops over the Atlantic Ocean and extends up to Siberia. It is also found that the response of the dryness and wetness conditions to global SST is more regional in summer, compared to the other seasons, when local processes may play a more important role

Postindustrial Ecologies: Industrial Rubble, Nature and the Limits of Representation

Ex-industrial areas, which occupy about 15 per cent of Bucharest’s surface, have generated emergent ecologies during the post-socialist period. The open-ended, eclectic and hard-to-define nature of such sites resists the common interpretations in terms of (industrial) heritage, nature, creative industries or speculative real estate development. Consequently, such postindustrial ecologies should be approached in a non-teleological way: neither as sanitized ruins, nor as fetishised nature, but as provisional ex-industrial materialities transformed by new human and non-human actors. I identify four main processes unfolding in such sites: urban mining; use as playgrounds for children; use as refuges for marginal humans and animals; and struggles for signification. None of these predominates.Les anciennes zones industrielles de Bucarest, qui occupent environ 15 % de la surface de la ville, ont généré des écologies émergentes au cours de la période post-socialiste. Le caractère ouvert, éclectique et difficile à définir de tels sites résiste aux interprétations communes en termes de patrimoine (industriel), de nature, d’industries créatives ou de développement immobilier spéculatif. Par conséquent, ces écologies postindustrielles doivent être abordées d'une manière non-téléologique : ni comme des ruines assainies, ni encore comme une nature fétichisée, mais en tant que matérialités ex-industrielles provisoires, transformées par de nouveaux acteurs humains et non-humains. J’identifie dans cet article quatre processus principaux qui se déroulent sur ces sites : des activités d’extraction urbaine (urban mining) ; des usages en tant qu’aire de jeux pour enfants ; des emplois comme refuge pour individus et animaux marginalisés ; des luttes pour donner du sens à ces lieux. Aucune de ces pratiques ne prédomine sur les autres

SOMA A Tool for Synthesizing and Optimizing Memory Accesses in ASICs

Arbitrary memory dependencies and variable latency memory systems are major obstacles to the synthesis of large-scale ASIC systems in high-level synthesis. This paper presents SOMA, a synthesis framework for constructing Memory Access Network (MAN) architectures that inherently enforce memory consistency in the presence of dynamic memory access dependencies. A fundamental bottleneck in any such network is arbitrating between concurrent accesses to a shared memory resource. To alleviate this bottleneck, SOMA uses an application-specific concurrency analysis technique to predict the dynamic memory parallelism profile of the application. This is then used to customize the MAN architecture. Depending on the parallelism profile, the MAN may be optimized for latency, throughput or both. The optimized MAN is automatically synthesized into gate-level structural Verilog using a flexible library of network building blocks. SOMA has been successfully integrated into an automated C-to-hardware synthesis flow, which generates standard cell circuits from unrestricted ANSI-C programs. Post-layout experiments demonstrate that application specific MAN construction significantly improves power and performance

Vanishing river ice cover in the lower part of the Danube basin – signs of a changing climate

Many of the world’s largest rivers in the extra tropics are covered with ice during the cold season, and in the Northern Hemisphere approximately 60% of the rivers experience significant seasonal effects of river ice. Here we present an observational data set of the ice cover regime for the lower part of the Danube River which spans over the period 1837–2016, and its the longest one on record over this area. The results in this study emphasize the strong impact of climate change on the occurrence of ice regime especially in the second part of the 20th century. The number of ice cover days has decreased considerably (~28days/century) mainly due to an increase in the winter mean temperature. In a long-term context, based on documentary evidences, we show that the ice cover occurrence rate was relatively small throughout the Medieval Warm Period (MWP), while the highest occurrence rates were found during the Maunder Minimum and Dalton Minimum periods. We conclude that the river ice regime can be used as a proxy for the winter temperature over the analyzed region and as an indicator of climate-change related impacts

Application of the 2-3 Agglomerative Hierarchical Classification on Web Usage Data.

In this paper we present a clustering of INRIA Web sites visited topics, using an hierarchical method, the 2-3 Hierarchical Ascending Classification proposed by Patrice Bertrand in 2002. The obtained clusters are then analysed for their relevance

Studying mixture effects on uptake and tissue distribution of PFAS in zebrafish (Danio rerio) using physiologically based kinetic (PBK) modelling

Per- and polyfluoroalkyl substances (PFAS) are ubiquitously distributed in the aquatic environment. They include persistent, mobile, bioaccumulative, and toxic chemicals and it is therefore critical to increase our understanding on their adsorption, distribution, metabolism, excretion (ADME). The current study focused on uptake of seven emerging PFAS in zebrafish (Danio rerio) and their potential maternal transfer. In addition, we aimed at increasing our understanding on mixture effects on ADME by developing a physiologically based kinetic (PBK) model capable of handling co-exposure scenarios of any number of chemicals. All studied chemicals were taken up in the fish to varying degrees, whereas only perfluorononanoate (PFNA) and perfluorooctanoate (PFOA) were quantified in all analysed tissues. Perfluorooctane sulfonamide (FOSA) was measured at concerningly high concentrations in the brain (Cmax over 15 μg/g) but also in the liver and ovaries. All studied PFAS were maternally transferred to the eggs, with FOSA and 6:2 perfluorooctane sulfonate (6,2 FTSA) showing significant (p 85 % of predictions within a 10-fold error and 60 % of predictions within a 3-fold error. At studied levels of PFAS exposure, competitive binding was not a critical factor for PFAS kinetics. Gill surface pH influenced uptake for some carboxylates but not the sulfonates. The developed PBK model provides an important tool in understanding kinetics under complex mixture scenarios and this use of New Approach Methodologies (NAMs) is critical in future risk assessment of chemicals and early warning systems

Classification 2-3 hiérarchique de données du Web

posterDans ce papier, nous présentons une classification des rubriques des URLs visitées du site Web de l'INRIA (équipes de recherche en particulier), en vue d'étudier l'impact de la structure du site Web et de la structure organisationnelle de l'INRIA sur les navigations des internautes. Pour cela nous avons utilisé notre algorithme de Classification Ascendante 2-3 Hiérarchique (2004) qui génère une structure plus riche que la CAH classique, en présentant une complexité identique soit n^2logn

Pre-Processing and Clustering Complex Data in E-Commerce Domain

This paper presents our preprocessing and clustering method on a clickstream dataset issued from e-commerce domain. The main contributions of this article are double. First, after presenting the clickstream dataset, we show how we build a rich data warehouse based an advanced preprocessing method. We take into account the intersite aspects in the given e-commerce domain, which offers an interesting data structuration. A preliminary statistical analysis based on such complex data i.e. time period clickstreams is given, emphasing the importance of intersite user visits in such a context. Secondly, we describe our crossed-clustering method which is applied on data generated from our data warehouse. Our preliminary results are interesting and promising illustrating the benefits of our WUM methods, even if more investigations are needed on the same dataset

Elasticity and Petri nets

Digital electronic systems typically use synchronous clocks and primarily assume fixed duration of their operations to simplify the design process. Time elastic systems can be constructed either by replacing the clock with communication handshakes (asynchronous version) or by augmenting the clock with a synchronous version of a handshake (synchronous version). Time elastic systems can tolerate static and dynamic changes in delays (asynchronous case) or latencies (synchronous case) of operations that can be used for modularity, ease of reuse and better power-delay trade-off. This paper describes methods for the modeling, performance analysis and optimization of elastic systems using Marked Graphs and their extensions capable of describing behavior with early evaluation. The paper uses synchronous elastic systems (aka latency-tolerant systems) for illustrating the use of Petri nets, however, most of the methods can be applied without changes (except changing the delay model associated with events of the system) to asynchronous elastic systems.Peer ReviewedPostprint (author's final draft