139 research outputs found

    Comprehending queries over finite maps

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    A Methodology for Engineering Collaborative and ad-hoc Mobile Applications using SyD Middleware

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    Today’s web applications are more collaborative and utilize standard and ubiquitous Internet protocols. We have earlier developed System on Mobile Devices (SyD) middleware to rapidly develop and deploy collaborative applications over heterogeneous and possibly mobile devices hosting web objects. In this paper, we present the software engineering methodology for developing SyD-enabled web applications and illustrate it through a case study on two representative applications: (i) a calendar of meeting application, which is a collaborative application and (ii) a travel application which is an ad-hoc collaborative application. SyD-enabled web objects allow us to create a collaborative application rapidly with limited coding effort. In this case study, the modular software architecture allowed us to hide the inherent heterogeneity among devices, data stores, and networks by presenting a uniform and persistent object view of mobile objects interacting through XML/SOAP requests and responses. The performance results we obtained show that the application scales well as we increase the group size and adapts well within the constraints of mobile devices

    Effectiveness of Corporate Social Media Activities to Increase Relational Outcomes

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    This study applies social media analytics to investigate the impact of different corporate social media activities on user word of mouth and attitudinal loyalty. We conduct a multilevel analysis of approximately 5 million tweets regarding the main Twitter accounts of 28 large global companies. We empirically identify different social media activities in terms of social media management strategies (using social media management tools or the web-frontend client), account types (broadcasting or receiving information), and communicative approaches (conversational or disseminative). We find positive effects of social media management tools, broadcasting accounts, and conversational communication on public perception

    AN EFFECTIVE PROPOSAL FOR REVEALING OF HIDDEN SET-LEVEL SEMANTICS

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    In the recent times, difficult SQL queries that are composed by scalar-level functions are formed to get hold of still extremely set-level semantics. These queries are not complex to write but moreover demanding for database engine to optimize, consequently results in expensive evaluation. Our work will highlight on relational data representation and some of the data analytics systems these days are based on considerable designs of parallel computing. We propose to broaden SQL by means of set predicates to manage set-level comparisons and these predicates, are combined by means of grouping, permit selection of dynamic groups by means of comparison among group as well as set of values. Our work will put forward augmenting of SQL by set predicate, to reveal obscured set-level semantics and suggest two approaches to process set predicates a Aggregate function-basis as well as bitmap index-based approach

    Introducing Perf to a Query Optimization Algorithm

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    User context and personalized learning: a federation of contextualized attention metadata

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    Nowadays, personalized education is a very hot topic in technology enhanced learning (TEL) research. To support students during their learning process, the first step consists in capturing the context in which they evolve. Users typically operate in a heterogeneous environment when learning, including learning tools such as Learning Management Systems and non-learning tools and services such as e-mails, instant messaging, or web pages. Thus, user attention in a given context defines the Contextualized Attention Metadata (CAM). Various initiatives and projects allow capturing CAMs in a knowledge workers’ environment not only in the TEL area, but also in other domains like Knowledge Work Support, Personal Information Management and Information Retrieval. After reviewing main existing approaches according to some specific criteria that are of main interest for capturing and sharing user contexts, we present in this paper a framework able to gather CAMs produced by any tool or computer system. The framework is built on the Web-Based Enterprise Management (WBEM) standard dedicated to system, network and application management. Attention information specific to heterogeneous tools are represented as a unified and extensible structure, and stored into a central repository compliant with the above-mentioned standard. To facilitate access to this attention repository, we introduced a middleware layer composed of two dynamic services: the first service allows users to define the attention data they want to collect, whereas the second service is dedicated to receive and retrieve the traces produced by computer systems. An implementation for collecting and storing CAM data generated by the Ariadne Finder and Moodle validates our approach

    Enabling Complex Semantic Queries to Bioinformatics Databases through Intuitive Search Over Data

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    Data integration promises to be one of the main catalysts in enabling new insights to be drawn from the wealth of biological data already available publicly. However, the heterogene- ity of the existing data sources still poses significant challenges for achieving interoperability among biological databases. Furthermore, merely solving the technical challenges of data in- tegration, for example through the use of common data representation formats, leaves open the larger problem. Namely, the steep learning curve required for understanding the data models of each public source, as well as the technical language through which the sources can be queried and joined. As a consequence, most of the available biological data remain practically unexplored today. In this thesis, we address these problems jointly, by first introducing an ontology-based data integration solution in order to mitigate the data source heterogeneity problem. We illustrate through the concrete example of Bgee, a gene expression data source, how relational databases can be exposed as virtual Resource Description Framework (RDF) graphs, through relational-to-RDF mappings. This has the important advantage that the original data source can remain unmodified, while still becoming interoperable with external RDF sources. We complement our methods with applied case studies designed to guide domain experts in formulating expressive federated queries targeting the integrated data across the domains of evolutionary relationships and gene expression. More precisely, we introduce two com- parative analyses, first within the same domain (using orthology data from multiple, inter- operable, data sources) and second across domains, in order to study the relation between expression change and evolution rate following a duplication event. Finally, in order to bridge the semantic gap between users and data, we design and im- plement Bio-SODA, a question answering system over domain knowledge graphs, that does not require training data for translating user questions to SPARQL. Bio-SODA uses a novel ranking approach that combines syntactic and semantic similarity, while also incorporating node centrality metrics to rank candidate matches for a given user question. Our results in testing Bio-SODA across several real-world databases that span multiple domains (both within and outside bioinformatics) show that it can answer complex, multi-fact queries, be- yond the current state-of-the-art in the more well-studied open-domain question answering. -- L’intĂ©gration des donnĂ©es promet d’ĂȘtre l’un des principaux catalyseurs permettant d’extraire des nouveaux aperçus de la richesse des donnĂ©es biologiques dĂ©jĂ  disponibles publiquement. Cependant, l’hĂ©tĂ©rogĂ©nĂ©itĂ© des sources de donnĂ©es existantes pose encore des dĂ©fis importants pour parvenir Ă  l’interopĂ©rabilitĂ© des bases de donnĂ©es biologiques. De plus, en surmontant seulement les dĂ©fis techniques de l’intĂ©gration des donnĂ©es, par exemple grĂące Ă  l’utilisation de formats standard de reprĂ©sentation de donnĂ©es, on laisse ouvert un problĂšme encore plus grand. À savoir, la courbe d’apprentissage abrupte nĂ©cessaire pour comprendre la modĂ©li- sation des donnĂ©es choisie par chaque source publique, ainsi que le langage technique par lequel les sources peuvent ĂȘtre interrogĂ©s et jointes. Par consĂ©quent, la plupart des donnĂ©es biologiques publiquement disponibles restent pratiquement inexplorĂ©s aujourd’hui. Dans cette thĂšse, nous abordons l’ensemble des deux problĂšmes, en introduisant d’abord une solution d’intĂ©gration de donnĂ©es basĂ©e sur ontologies, afin d’attĂ©nuer le problĂšme d’hĂ©tĂ©- rogĂ©nĂ©itĂ© des sources de donnĂ©es. Nous montrons, Ă  travers l’exemple de Bgee, une base de donnĂ©es d’expression de gĂšnes, une approche permettant les bases de donnĂ©es relationnelles d’ĂȘtre publiĂ©s sous forme de graphes RDF (Resource Description Framework) virtuels, via des correspondances relationnel-vers-RDF (« relational-to-RDF mappings »). Cela prĂ©sente l’important avantage que la source de donnĂ©es d’origine peut rester inchangĂ©, tout en de- venant interopĂ©rable avec les sources RDF externes. Nous complĂ©tons nos mĂ©thodes avec des Ă©tudes de cas appliquĂ©es, conçues pour guider les experts du domaine dans la formulation de requĂȘtes fĂ©dĂ©rĂ©es expressives, ciblant les don- nĂ©es intĂ©grĂ©es dans les domaines des relations Ă©volutionnaires et de l’expression des gĂšnes. Plus prĂ©cisĂ©ment, nous introduisons deux analyses comparatives, d’abord dans le mĂȘme do- maine (en utilisant des donnĂ©es d’orthologie provenant de plusieurs sources de donnĂ©es in- teropĂ©rables) et ensuite Ă  travers des domaines interconnectĂ©s, afin d’étudier la relation entre le changement d’expression et le taux d’évolution suite Ă  une duplication de gĂšne. Enfin, afin de mitiger le dĂ©calage sĂ©mantique entre les utilisateurs et les donnĂ©es, nous concevons et implĂ©mentons Bio-SODA, un systĂšme de rĂ©ponse aux questions sur des graphes de connaissances domaine-spĂ©cifique, qui ne nĂ©cessite pas de donnĂ©es de formation pour traduire les questions des utilisateurs vers SPARQL. Bio-SODA utilise une nouvelle ap- proche de classement qui combine la similaritĂ© syntactique et sĂ©mantique, tout en incorporant des mĂ©triques de centralitĂ© des nƓuds, pour classer les possibles candidats en rĂ©ponse Ă  une question utilisateur donnĂ©e. Nos rĂ©sultats suite aux tests effectuĂ©s en utilisant Bio-SODA sur plusieurs bases de donnĂ©es Ă  travers plusieurs domaines (tantĂŽt liĂ©s Ă  la bioinformatique qu’extĂ©rieurs) montrent que Bio-SODA rĂ©ussit Ă  rĂ©pondre Ă  des questions complexes, en- gendrant multiples entitĂ©s, au-delĂ  de l’état actuel de la technique en matiĂšre de systĂšmes de rĂ©ponses aux questions sur les donnĂ©es structures, en particulier graphes de connaissances

    Enhancing Trajectory Prediction through Self-Supervised Waypoint Noise Prediction

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    Trajectory prediction is an important task that involves modeling the indeterminate nature of traffic actors to forecast future trajectories given the observed trajectory sequences. However, current methods confine themselves to presumed data manifolds, assuming that trajectories strictly adhere to these manifolds, resulting in overly simplified predictions. To this end, we propose a novel approach called SSWNP (Self-Supervised Waypoint Noise Prediction). In our approach, we first create clean and noise-augmented views of past observed trajectories across the spatial domain of waypoints. We then compel the trajectory prediction model to maintain spatial consistency between predictions from these two views, in addition to the trajectory prediction task. Introducing the noise-augmented view mitigates the model's reliance on a narrow interpretation of the data manifold, enabling it to learn more plausible and diverse representations. We also predict the noise present in the two views of past observed trajectories as an auxiliary self-supervised task, enhancing the model's understanding of the underlying representation and future predictions. Empirical evidence demonstrates that the incorporation of SSWNP into the model learning process significantly improves performance, even in noisy environments, when compared to baseline methods. Our approach can complement existing trajectory prediction methods. To showcase the effectiveness of our approach, we conducted extensive experiments on three datasets: NBA Sports VU, ETH-UCY, and TrajNet++, with experimental results highlighting the substantial improvement achieved in trajectory prediction tasks.Comment: Under revie
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