Search results for "Database"
showing 10 items of 2136 documents
Towards Graphical Query Notation for Semantic Databases
2015
We describe a notation and a tool for schema-enabled visual/diagrammatic creation of SPARQL queries over RDF databases. The notation and the tool support both the standard basic query pattern comprising a main query class and possibly linked condition classes and means for aggregate query definition and placing conditions over aggregates including also aggregation of aggregate results. We discuss the applicability of the tool for ad-hoc query formulation in practical use cases.
Mobile Search - Social Network Search Using Mobile Devices
2008
During the last years progress in Web search engines has been made to the point that relevant information can be reached easily most of the time. However very little empirical research has been carried to study Web search in highly dynamic social network environments composed of mobile devices. The aim of this work was therefore to investigate novel approaches that took advantage of the social network environment inherent to mobile peer-to-peer paradigm. The work focused mainly on the development of a prototype for mobile search concept. The prototype was built on top of Drupal content site management system. This study suggests that the methods presented can be a complement to traditional …
HTTP-level e-commerce data based on server access logs for an online store
2020
Abstract Web server logs have been extensively used as a source of data on the characteristics of Web traffic and users’ navigational patterns. In particular, Web bot detection and online purchase prediction using methods from artificial intelligence (AI) are currently key areas of research. However, in reality, it is hard to obtain logs from actual online stores and there is no common dataset that can be used across different studies. Moreover, there is a lack of studies exploring Web traffic over a longer period of time, due to the unavailability of long-term data from server logs. The need to develop reliable models of Web traffic, Web user navigation, and e-customer behaviour calls for …
Practical Aspects of Log File Analysis for E-Commerce
2013
The paper concerns Web server log file analysis to discover knowledge useful for online retailers. Data for one month of the online bookstore operation was analyzed with respect to the probability of making a purchase by e-customers. Key states and characteristics of user sessions were distinguished and their relations to the session state connected with purchase confirmation were analyzed. Results allow identification of factors increasing the probability of making a purchase in a given Web store and thus, determination of user sessions which are more valuable in terms of e-business profitability. Such results may be then applied in practice, e.g. in a method for personalized or prioritize…
Delfos: the Oracle to Predict NextWeb User's Accesses
2007
Despite the wide and intensive research efforts focused on Web prediction and prefetching techniques aimed to reduce user's perceived latency, few attempts to implement and use them in real environments have been done, mainly due to their complexity and supposed limitations that low user available bandwidths imposed few years ago. Nevertheless, current user bandwidths open a new scenario for prefetching that becomes again an interesting option to improve web performance. This paper presents Delfos, a framework to perform web predictions and prefetching on a real environment that tries to cover the existing gap between research and praxis. Delfos is integrated in the web architecture without…
Semantic to intelligent web era
2013
International audience; The Web has known a very fast evolution: going from the Web 1.0, known as Web of Documents where users are merely consumers of static information, to the more dynamic Web 2.0, known as social or collaborative Web where users produce and consume information simultaneously, and entering the more sophisticated Web 3.0, known as the Semantic Web by giving information a well-defined meaning so that it becomes more easily accessible by human users and automated processes. Fostering service intelligence and atomicity (the ability of autonomous services to interact automatically), remains one of the most upcoming challenges of the Semantic Web. This promotes the dawn of a ne…
Complex adaptative systems and computational simulation in Archaeology
2017
Traditionally the concept of ‘complexity’ is used as a synonym for ‘complex society’, i.e., human groups with characteristics such as urbanism, inequalities, and hierarchy. The introduction of Nonlinear Systems and Complex Adaptive Systems to the discipline of archaeology has nuanced this concept. This theoretical turn has led to the rise of modelling as a method of analysis of historical processes. This work has a twofold objective: to present the theoretical current characterized by generative thinking in archaeology and to present a concrete application of agent-based modelling to an archaeological problem: the dispersal of the first ceramic production in the western Mediterranean.
Offshore wind metadata management
2014
Offshore wind energy is gaining more and more attention from industry and research community due to its high potential in producing green energy and lowering price on electricity consumption. However, offshore wind is facing many challenges, and hence it is still expensive to install in large scale. It therefore needs to be considered from different aspects of technologies in order to overcome these challenges. One of the problems of the offshore wind is that information comes from different sources with diversity in types and format. Besides, there are existing wind databases that should be utilised in order to enrich the knowledge base of the wind domain. This paper describes an approach …
Technological and legislative status point of stationary energy storages in the EU
2019
Abstract European renewable generation has been supported through several policy instruments in the last decades, and this has caused a significant growth of the renewable energy sector, spurred by the ambitious climate and energy policy targets. Despite this impetuous growth, the electricity infrastructure is not yet ready to accept increasing shares of variable renewable energy sources (RES) generation, and this is causing grid balance challenges, due to the inherently variable nature of the PV and wind energy. In order to overcome this issue, allowing higher shares of renewable generation in the energy sector, energy storage (ES) systems are becoming increasingly competitive in the globa…
The use of core-shell high-performance liquid chromatography column technology to improve biogenic amine quantification in wine
2015
BACKGROUND HPLC column technology has been improved, providing better resolution of closely eluting compounds, better analyte sensitivity, and shorter analysis times. The core-shell technology columns offer a faster analysis through the use of shorter columns without compromising resolution. The aim of this work was to improve the methods for determination of biogenic amines (BAs) in wine using the new HPLC PFP core-shell column technology. RESULTS Two different elution programs were designed to quantify BAs with the core-shell PFP column. Program I flow rate was 2 mL min−1. The total elution time was 10 min. In elution program II, the flow rate was 0.8 mL min−1 and the total elution time w…