856 research outputs found
Programming patterns and development guidelines for Semantic Sensor Grids (SemSorGrid4Env)
The web of Linked Data holds great potential for the creation of semantic applications that can combine self-describing structured data from many sources including sensor networks. Such applications build upon the success of an earlier generation of 'rapidly developed' applications that utilised RESTful APIs. This deliverable details experience, best practice, and design patterns for developing high-level web-based APIs in support of semantic web applications and mashups for sensor grids. Its main contributions are a proposal for combining Linked Data with RESTful application development summarised through a set of design principles; and the application of these design principles to Semantic Sensor Grids through the development of a High-Level API for Observations. These are supported by implementations of the High-Level API for Observations in software, and example semantic mashups that utilise the API
Implementation and Deployment of a Library of the High-level Application Programming Interfaces (SemSorGrid4Env)
The high-level API service is designed to support rapid development of thin web applications and mashups beyond the state of the art in GIS, while maintaining compatibility with existing tools and expectations. It provides a fully configurable API, while maintaining a separation of concerns between domain experts, service administrators and mashup developers. It adheres to REST and Linked Data principles, and provides a novel bridge between standards-based (OGC O&M) and Semantic Web approaches. This document discusses the background motivations for the HLAPI (including experiences gained from any previously implemented versions), before moving onto specific details of the final implementation, including configuration and deployment instructions, as well as a full tutorial to assist mashup developers with using the exposed observation data
Resource allocation model for sensor clouds under the sensing as a service paradigm
The Sensing as a Service is emerging as a new Internet of Things (IoT) business model for sensors and data sharing in the cloud. Under this paradigm, a resource allocation model for the assignment of both sensors and cloud resources to clients/applications is proposed. This model, contrarily to previous approaches, is adequate for emerging IoT Sensing as a Service business models supporting multi-sensing applications and mashups of Things in the cloud. A heuristic algorithm is also proposed having this model as a basis. Results show that the approach is able to incorporate strategies that lead to the allocation of fewer devices, while selecting the most adequate ones for application needs.FCT (Foundation for Science and Technology) from Portugal within CEOT (Center for Electronic, Optoelectronic and Telecommunications)
UID/MULTI/00631/2019info:eu-repo/semantics/publishedVersio
A look at cloud architecture interoperability through standards
Enabling cloud infrastructures to evolve into a transparent platform while preserving integrity raises interoperability issues. How components are connected needs to be addressed. Interoperability requires standard data models and communication encoding technologies compatible with the existing Internet infrastructure. To reduce vendor lock-in situations, cloud computing must implement universal strategies regarding standards, interoperability and portability. Open standards are of critical importance and need to be embedded into interoperability solutions. Interoperability is determined at the data level as well as the service level. Corresponding modelling standards and integration solutions shall be analysed
Privacy-aware Linked Widgets
The European General Data Protection Regulation (GDPR) brings
new challenges for companies, who must demonstrate that their
systems and business processes comply with usage constraints
specified by data subjects. However, due to the lack of standards,
tools, and best practices, many organizations struggle to adapt their
infrastructure and processes to ensure and demonstrate that all
data processing is in compliance with users' given consent. The
SPECIAL EU H2020 project has developed vocabularies that can
formally describe data subjects' given consent as well as methods
that use this description to automatically determine whether
processing of the data according to a given policy is compliant
with the given consent. Whereas this makes it possible to determine
whether processing was compliant or not, integration of the
approach into existing line of business applications and ex-ante
compliance checking remains an open challenge. In this short paper,
we demonstrate how the SPECIAL consent and compliance framework
can be integrated into Linked Widgets, a mashup platform, in
order to support privacy-aware ad-hoc integration of personal data.
The resulting environment makes it possible to create data integration
and processing workflows out of components that inherently
respect usage policies of the data that is being processed and are
able to demonstrate compliance. We provide an overview of the
necessary meta data and orchestration towards a privacy-aware
linked data mashup platform that automatically respects subjects'
given consents. The evaluation results show the potential of our
approach for ex-ante usage policy compliance checking within the
Linked Widgets Platforms and beyond
Virtual sensor networks: collaboration and resource sharing
This thesis contributes to the advancement of the Sensing as a Service (SeaaS),
based on cloud infrastructures, through the development of models and
algorithms that make an efficient use of both sensor and cloud resources while
reducing the delay associated with the data flow between cloud and client
sides, which results into a better quality of experience for users. The first models
and algorithms developed are suitable for the case of mashups being managed
at the client side, and then models and algorithms considering mashups
managed at the cloud were developed. This requires solving multiple problems:
i) clustering of compatible mashup elements; ii) allocation of devices
to clusters, meaning that a device will serve multiple applications/mashups;
iii) reduction of the amount of data flow between workplaces, and associated
delay, which depends on clustering, device allocation and placement of workplaces.
The developed strategies can be adopted by cloud service providers
wishing to improve the performance of their clouds.
Several steps towards an efficient Se-aaS business model were performed.
A mathematical model was development to assess the impact (of resource
allocations) on scalability, QoE and elasticity. Regarding the clustering of
mashup elements, a first mathematical model was developed for the selection
of the best pre-calculated clusters of mashup elements (virtual Things), and
then a second model is proposed for the best virtual Things to be built (non
pre-calculated clusters). Its evaluation is done through heuristic algorithms
having such model as a basis. Such models and algorithms were first developed
for the case of mashups managed at the client side, and after they
were extended for the case of mashups being managed at the cloud. For the
improvement of these last results, a mathematical programming optimization
model was developed that allows optimal clustering and resource allocation
solutions to be obtained. Although this is a computationally difficult
approach, the added value of this process is that the problem is rigorously
outlined, and such knowledge is used as a guide in the development of better
a heuristic algorithm.Esta tese contribui para o avanço tecnológico do modelo de Sensing as a Service
(Se-aaS), baseado em infraestrutura cloud, através do desenvolvimento
de modelos e algoritmos que resolvem o problema da alocação eficiente de
recursos, melhorando os métodos e técnicas atuais e reduzindo os tempos associados
`a transferência dos dados entre a cloud e os clientes, com o objetivo
de melhorar a qualidade da experiência dos seus utilizadores. Os primeiros
modelos e algoritmos desenvolvidos são adequados para o caso em que as
mashups são geridas pela aplicação cliente, e posteriormente foram desenvolvidos
modelos e algoritmos para o caso em que as mashups são geridas
pela cloud. Isto implica ter de resolver múltiplos problemas: i) Construção
de clusters de elementos de mashup compatíveis; ii) Atribuição de dispositivos
físicos aos clusters, acabando um dispositivo físico por servir m´ múltiplas
aplicações/mashups; iii) Redução da quantidade de transferência de dados
entre os diversos locais da cloud, e consequentes atrasos, o que dependente
dos clusters construídos, dos dispositivos atribuídos aos clusters e dos locais
da cloud escolhidos para realizar o processamento necessário. As diferentes
estratégias podem ser adotadas por fornecedores de serviço cloud que queiram
melhorar o desempenho dos seus serviços.(…
A Semantically Enabled Service Architecture for Mashups over Streaming and Stored Data
Sensing devices are increasingly being deployed to monitor
the physical world around us. One class of application for which sensor data is pertinent is environmental decision support systems, e.g. good emergency response. However, in order to interpret the readings from the sensors, the data needs to be put in context through correlation with other sensor readings, sensor data histories, and stored data, as well as juxtaposing with maps and forecast models. In this paper we use a good emergency response planning application to identify requirements for a semantic sensor web. We propose a generic service architecture to satisfy the requirements that uses semantic annotations to support well-informed interactions between the services. We present the SemSor-Grid4Env realisation of the architecture and illustrate its capabilities in the context of the example application
MusA: Using Indoor Positioning and Navigation to Enhance Cultural Experiences in a museum
In recent years there has been a growing interest into the use of multimedia mobile guides in museum environments. Mobile devices have the capabilities to detect the user context and to provide pieces of information suitable to help visitors discovering and following the logical and emotional connections that develop during the visit. In this scenario, location based services (LBS) currently represent an asset, and the choice of the technology to determine users' position, combined with the definition of methods that can effectively convey information, become key issues in the design process. In this work, we present MusA (Museum Assistant), a general framework for the development of multimedia interactive guides for mobile devices. Its main feature is a vision-based indoor positioning system that allows the provision of several LBS, from way-finding to the contextualized communication of cultural contents, aimed at providing a meaningful exploration of exhibits according to visitors' personal interest and curiosity. Starting from the thorough description of the system architecture, the article presents the implementation of two mobile guides, developed to respectively address adults and children, and discusses the evaluation of the user experience and the visitors' appreciation of these application
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