Search results for "Protocol"
showing 10 items of 1808 documents
HOWERD: A Hidden Markov Model for Automatic OWL-ERD Alignment
2016
The HOWERD model for estimating the most likely alignment between an OWL ontology and an Entity Relation Diagram (ERD) is presented. Automatic alignment between relational schema and ontology represents a big challenge in Semantic Web research due to the different expressiveness of these representations. A relational schema is less expressive than the ontology; this is a non trivial problem when accessing data via an ontology and for ontology storing by means of a relational schema. Existent alignment methodologies fail in loosing some contents of the involved representations because the ontology captures more semantic information, and several elements are left unaligned. HOWERD relies on a…
Spatialization of the Semantic Web
2012
syntax for Horn-like rules. The SWRL as the form, antecedentconsequent, where both antecedent and consequent are conjunctions of atoms written a1^ ... ^ an. Atoms in rules can be of the form C(x), P(x,y), Q(x,z), sameAs(x,y), differentFrom(x,y), or builtIn(pred, z1, ..., zn), where C is an OWL description, P is an OWL individual-valued property, Q is an OWL data-valued property, pred is a datatype predicate URIref, x and y are either individual-valued variables or OWL individuals, and z, z1, ... zn are either data-valued variables or OWL data literals. An OWL data literal is either a typed literal or a plain literal. Variables are indicated by using the standard convention of prefixing the…
Working with Multiple Ontologies on the Semantic Web.
2016
The standardization of the second generation Web Ontology Language, OWL, leaves a crucial issue for Web-based ontologies unsatisfactorily resolved: how to represent and reason with multiple distinct, but linked, ontologies. OWL provides the owl:imports construct which, roughly, allows Web ontologies to include other Web ontologies, but only by merging all the linked ontologies into a single logical "space". Recent work on multidimensional logics, fusions and other combinations of modal logics, distributed and contextual logics, and the like have tried to find formalisms wherein knowledge bases (and their logic) are kept more distinct but yet affect each other. These formalisms have various …
Specific protocol (SENSLOG) over TCP/IP for sensors applications
2005
The objective is to obtain an embedded system using a microcontroller that will communicate with other devices over a specific protocol (SENSLOG) over TCP/IP for sensors applications. The protocol has been designed for this application, but the commands are generic. They can be used for any type of sensing. We must take into account that this program will run in a microcontroller and it will communicate with another program running in a PC. The protocol is based on commands, like SMTP. From the PC we will send commands to the microcontroller to do specific tasks, and if it is necessary, the microcontroller will answer to the PC. Some of the functions designed for this protocol are: to contr…
Does ns2 Really Simulate MPLS Networks?
2008
Multi Protocol Label Switching (MPLS) is being used in many corporate networks and public infrastructures and as a backbone technology of many Autonomous Systems. Because of its importance, what is needed is to find out simulators able to simulate MPLS networks whose results reflect the real environment as much as possible. In this article, we will show real measurements from the Railway Infrastructure Administrator (ADIF, the Spanish railway infrastructure manager) MPLS network and we will compare them with the results obtained by the freeware simulator ns2. We will check the level of reliability provided by the simulator and we will know under which parameters its results will be similar …
OntoSTEP: Enriching product model data using ontologies
2012
The representation and management of product lifecycle information is critical to any manufacturing organization. Different modeling languages are used at different lifecycle stages, for example STEP's EXPRESS may be used at a detailed design stage, while UML may be used for initial design stages. It is necessary to consolidate product information created using these different languages to build a coherent knowledge base. In this paper, we present an approach to enable the translation of STEP schema and its instances to Ontology Web Language (OWL). This gives a model-which we call OntoSTEP-that can easily be integrated with any OWL ontologies to create a semantically rich model. As an examp…
Students evaluating Internet sources – From versatile evaluators to uncritical readers
2008
The Internet is a significant information resource for students due to the ease of access it allows to a vast amount of information. As the quality of the information on the Internet varies, it is important that students are able to evaluate such information critically. The aim of the study was to investigate how students evaluate Internet sources in an authentic learning task. Upper secondary school students ( n = 25) were asked to look for source material on the Internet in order to write an essay. They were asked to verbalize their thoughts during the material gathering process. Their verbalizations and actions on the Internet were recorded and analyzed. The five evaluation profiles eme…
Germinación y cultivo de Marsilea quadrifolia L. (MARSILEACEAE): Desarrollo de la planta a lo largo de su ciclo vital
2016
Algunas plantas con sistemas reproductivos evolutivamente primitivos, y especialmente aquellas que habitan en sistemas acuáticos explotados agronómicamente por el hombre, se ven en la actualidad seriamente amenazadas en el medio natural. Los productos químicos utilizados en exceso en la agricultura intensiva han degradado estos ecosistemas hasta hacer imposible la supervivencia de las especies más sensibles. Este trabajo se ha cofinanciado por la Generalitat Valenciana (Conselleria de Agricultura, Medio Ambiente, Cambio Climático y Desarrollo Rural, Servicio de Biodiversidad) y la Universitat de València.
Col : A Data Collection Protocol for Vanet
2012
International audience; In this paper, we present a protocol to collect data within a vehicular ad hoc network (VANET). In spite of the intrinsic dynamic of such network, our protocol simultaneously offers three relevant properties: (1) It allows any vehicle to collect data beyond its direct neighborhood (i.e., vehicles within direct communication range) using vehicle-to-vehicle communications only (i.e., the infrastructure is not required); (2) It tolerates possible network partitions; (3) It works on demand and stops when the data collection is achieved. To the best of our knowledge, this is the first collect protocol having these three characteristics. All that is chiefly obtained thanks…
LPV model identification for gain scheduling control: An application to rotating stall and surge control problem
2006
Abstract We approach the problem of identifying a nonlinear plant by parameterizing its dynamics as a linear parameter varying (LPV) model. The system under consideration is the Moore–Greitzer model which captures surge and stall phenomena in compressors. The control task is formulated as a problem of output regulation at various set points (stable and unstable) of the system under inputs and states constraints. We assume that inputs, outputs and scheduling parameters are measurable. It is worth pointing out that the adopted technique allows for identification of an LPV model's coefficients without the requirements of slow variations amongst set points. An example of combined identification…