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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
521

Interoperabilidade dos dispositivos móveis / Interoperabilidade dos dispositivos móveis / Device móbiles interoperability / Device móbiles interoperability

Paes, Wander de Moraes 06 August 2008 (has links)
Made available in DSpace on 2016-04-29T14:23:45Z (GMT). No. of bitstreams: 1 Wander de Moraes Paes.pdf: 1162817 bytes, checksum: 45da7f91468b50a422ea7d8a7cd4f2a1 (MD5) Previous issue date: 2008-08-06 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The concept of sharing computing resources among WEB participants, has been gradually extended to support scenarios in wireless world, networks, mobile devices which introduce a variety possible uses. Wireless devices become a key of sharing information among peoples. In this point of view we present the main challenges in pervasive/ubiquitous concepts for wireless applications networks, focusing on the resource of systems and information interoperability. The idea about interdisciplinary culture, as instrument of dissemination and production of the knowledge in the digital environment, is a factor that also is applied to the environment of the mobile devices that remain the necessity of a study related to the interoperability what refers to the communication and the exchange information among peoples. This phenomenon shows up as a trend of the systems solutions in Wireless environments and WEB due to variety use of the electronic devices without wire as: cellular, PDA´s, Smartphone and Pocket PC. The consolidation of the Internet as a collaboration environment as well as the sprout of the mobile applications had directly influenced the business solutions and the systems architecture in the contemporary society. This new cartographic map of the decentralized services in cyberspace is fertile environment for the study about mobile medias environment and its consequence among stakeholders in ciberspace, a scene that represents significant impact in the contribution of the information in the development of the interfaces of the mobile systems. This map of information characterizes for a harmonic acquaintance between the centralization and the decentralization of the information in the mobile network. Therefore, the specific objective of the thesis involves the idea about mobile interoperability devices under the phenomenal about: mobility, cyberspace, portable devices and the technological aspects of the hybrid networks and new media architecture. The emergency of this context represents an important research study of the technology due a great solution offered by telecom corporations and political government. The aim of this research does not only approach the technological aspect centered in design of systems and programs, but also it focuses the benefits of the interoperability about all the flow of the information, deriving of the decentralized flow of information in wireless environment and WEB, these aspects had influenced the companies and the society in the digital culture. These solutions prevail are inside the same solution for the collaboration and people integration in cyberspace / O conceito da cultura interdisciplinar, como instrumento de disseminação e produção do conhecimento no ambiente digital é um fator que também se aplica ao ambiente dos dispositivos móveis. O que traduz a necessidade de um estudo relacionado à interoperabilidade das informações no que tange a comunicação e a troca das informações por meio destes últimos. O tecnologia sem fio afirma-se como tendência das soluções sistêmicas devido à popularização do uso dos dispositivos eletrônicos (celular, PDA´s, Smartphone e Pocket PC) e principalmente pelo papel da sociedade como parte integrante no dinamismo do processo de colaboração das informações. A consolidação da Internet e do surgimento da tecnologia móvel, sob a perspectiva da colaboração das informações, influenciou diretamente as soluções de negócio e os sistemas computacionais na sociedade contemporânea. Esse novo mapa cartográfico dos serviços descentralizados no ciberespaço é um palco fértil para o estudo da influência das mídias móveis e seu reflexo nas relações humanas. O que representou um impacto significativo no ambiente de desenvolvimento de sistemas inserido num ambiente heterogêneo que se caracteriza também por uma convivência harmônica entre a centralização e a descentralização das informações. Portanto, o objetivo específico dessa dissertação é apresentar a idéia da interoperabilidade dos dispositivos móveis sob o contexto dos fenômenos contemporâneos da mobilidade, ciberespaço móvel e os aspectos tecnológicos das redes e arquitetura de sistemas móveis. A emergência deste contexto representa um palco fértil para o estudo da tecnologia sem fio oferecida pelas grandes corporações. O foco desta pesquisa não aborda somente os aspectos tecnológicos centrados no design de sistemas e programas, mas também enfoca a interoperabilidade em todo o fluxo das informações na WEB e no emergente ambiente tecnológico Wireless com abordagens que influenciaram as empresas e a sociedade na cultura digital. O que representa o meio digital móvel e a interoperabilidade como parte integrante de uma mesma inovação tecnológica como solução para a colaboração das informações e integração de pessoas no ciberespaço
522

Hybrid State-Transactional Database for Product Lifecycle Management Features in Multi-Engineer Synchronous Heterogeneous Computer-Aided Design

Shumway, Devin James 01 April 2017 (has links)
There are many different programs that can perform Computer Aided Design (CAD). In order for these programs to share data, file translations need to occur. These translations have typically been done by IGES and STEP files. With the work done at the BYU CAD Lab to create a multi-engineer synchronous heterogeneous CAD environment, these translation processes have become synchronous by using a server and a database to manage the data. However, this system stores part data in a database. The data in the database cannot be used in traditional Product Lifecycle Management systems. In order to remedy this, a new database was developed that enables every edit made in a CAD part across multiple CAD systems to be stored as well as worked on simultaneously. This allows users to access every action performed in a part. Branching was introduced to the database which allows users to work on multiple configurations of a part simultaneously and reduces file save sizes for different configurations by 98.6% compared to those created by traditional CAD systems.
523

Weaving the semantic web: Contributions and insights

Cregan, Anne, Computer Science & Engineering, Faculty of Engineering, UNSW January 2008 (has links)
The semantic web aims to make the meaning of data on the web explicit and machine processable. Harking back to Leibniz in its vision, it imagines a world of interlinked information that computers `understand' and `know' how to process based on its meaning. Spearheaded by the World Wide Web Consortium, ontology languages OWL and RDF form the core of the current technical offerings. RDF has successfully enabled the construction of virtually unlimited webs of data, whilst OWL gives the ability to express complex relationships between RDF data triples. However, the formal semantics of these languages limit themselves to that aspect of meaning that can be captured by mechanical inference rules, leaving many open questions as to other aspects of meaning and how they might be made machine processable. The Semantic Web has faced a number of problems that are addressed by the included publications. Its germination within academia, and logical semantics has seen it struggle to become familiar, accessible and implementable for the general IT population, so an overview of semantic technologies is provided. Faced with competing `semantic' languages, such as the ISO's Topic Map standards, a method for building ISO-compliant Topic Maps in the OWL DL language has been provided, enabling them to take advantage of the more mature OWL language and tools. Supplementation with rules is needed to deal with many real-world scenarios and this is explored as a practical exercise. The available syntaxes for OWL have hindered domain experts in ontology building, so a natural language syntax for OWL designed for use by non-logicians is offered and compared with similar offerings. In recent years, proliferation of ontologies has resulted in far more than are needed in any given domain space, so a mechanism is proposed to facilitate the reuse of existing ontologies by giving contextual information and leveraging social factors to encourage wider adoption of common ontologies and achieve interoperability. Lastly, the question of meaning is addressed in relation to the need to define one's terms and to ground one's symbols by anchoring them effectively, ultimately providing the foundation for evolving a `Pragmatic Web' of action.
524

A Theory of Mediating Connectors to achieve Interoperability

Spalazzese, Romina 18 April 2011 (has links) (PDF)
Systems populating the Ubiquitous Computing environment are characterized by an often extreme level of heterogeneity at different layers which prevents their seamless interoperability. In this environment, heterogeneous protocols would cooperate to reach some common goal even though they meet dynamically and do not have a priori knowledge of each other. Although numerous efforts have been done in the literature, the automated and run-time interoperability is still an open challenge for such environment. Therefore, this thesis focuses on overcoming the interoperability problem between heterogeneous protocols in the Ubiquitous Computing. In particular, we aim at providing a means to drop the interoperability barriers by automatically eliciting a way for the protocols to interact. The solution we propose is the automated synthesis of emerging mediating connectors (also called mediators or connectors). Specifically, we concentrate our efforts to: (i) devising AMAzING, a process to synthesize mediators, (ii) characterizing protocol mismatches and related mediator patterns, and (iii) designing MediatorS, a theory of mediating connectors. The theory, and the process, are put in practice by applying them to a real world application, and have been adopted by the European Research Project CONNECT.
525

An agent framework to support sensor networks’ setup and adaptation

de Freitas, Edison Pignaton, Heimfarth, Tales, Ferreira, Armando Morado, Wagner, Flávio Rech, Pereira, Carlos Eduardo, Larsson, Tony January 2009 (has links)
Sensor networks are being used in several emerging applications not even imagined some years ago due to advances in sensing, computing, and communication techniques. However, these advances also pose various challenges that must be faced. One important challenge is related to the autonomous capability needed to setup and adapt the networks, which decentralizes the control of the network, saving communication and energy resources. Middleware technology helps in addressing this kind of problem, but there is still a need for additional solutions, particularly considering dynamic changes in users' requirements and operation conditions. This paper presents an agent-based framework acting as an integral part of a middleware to support autonomous setup and adaptation of sensor networks. It adds interoperability among heterogeneous nodes in the network, by means of autonomous behavior and reasoning. These features also address the needs for system setup and adaptations in the network, reducing the communication overhead and decentralizing the decision making mechanism. Additionally, preliminary results are also presented.
526

Μέθοδοι και τεχνικές ανακάλυψης γνώσης στο σημαντικό ιστό : παραγωγική απόκτηση γνώσης από οντολογικά έγγραφα και η τεχνική της σημασιακής προσαρμογής / Methods and techniques for semantic web knowledge discovery : deductive knowledge acquisition from ontology documents and the semantic profiling technique

Κουτσομητρόπουλος, Δημήτριος 03 August 2009 (has links)
Ο Σημαντικός Ιστός (Semantic Web) είναι ένας συνδυασμός τεχνολογιών και προτύπων με σκοπό να προσδοθεί στη διαδικτυακή πληροφορία αυστηρά καθορισμένη σημασιακή δομή και ερμηνεία. Στόχος είναι να μπορούν οι χρήστες του Παγκόσμιου Ιστού καθώς και αυτοματοποιημένοι πράκτορες να επεξεργάζονται, να διαχειρίζονται και να αξιοποιούν την κατάλληλα χαρακτηρισμένη πληροφορία με τρόπο ευφυή και αποδοτικό. Ωστόσο, παρά τις τεχνικές που έχουν κατά καιρούς προταθεί, δεν υπάρχει ξεκάθαρη μέθοδος ώστε, αξιοποιώντας το φάσμα του Σημαντικού Ιστού, η διαδικτυακή πληροφορία να ανακτάται με τρόπο παραγωγικό, δηλαδή με βάση τα ήδη εκπεφρασμένα γεγονότα να συνάγεται νέα, άρρητη πληροφορία. Για την αντιμετώπιση αυτής της κατάστασης, αρχικά εισάγεται και προσδιορίζεται το πρόβλημα της Ανακάλυψης Γνώσης στο Σημαντικό Ιστό (Semantic Web Knowledge Discovery, SWKD). Η Ανακάλυψη Γνώσης στο Σημαντικό Ιστό εκμεταλλεύεται το σημασιακό υπόβαθρο και τις αντίστοιχες σημασιακές περιγραφές των πληροφοριών, όπως αυτές είναι θεμελιωμένες σε μια λογική θεωρία (οντολογίες εκφρασμένες σε γλώσσα OWL). Βάσει αυτών και με τη χρήση των κατάλληλων μηχανισμών αυτοματοποιημένου συλλογισμού μπορεί να συμπεραθεί νέα, άδηλη γνώση, η οποία, μέχρι τότε, μόνο υπονοούνταν στα ήδη υπάρχοντα δεδομένα. Για να απαντηθεί το ερώτημα αν και σε πιο βαθμό οι τεχνολογίες και η λογική θεωρία του Σημαντικού Ιστού συνεισφέρουν αποδοτικά και εκφραστικά στο πρόβλημα της SWKD καταρτίζεται μια πρότυπη Μεθοδολογία Ανακάλυψης Γνώσης στο Σημαντικό Ιστό, η οποία θεμελιώνεται σε πρόσφατα θεωρητικά αποτελέσματα, αλλά και στην ποιοτική και πειραματική συγκριτική αξιολόγηση διαδεδομένων μηχανισμών συμπερασμού (inference engines) που βασίζονται σε Λογικές Περιγραφής (Description Logics). H αποδοτικότητα και η εκφραστικότητα της μεθόδου αυτής δείχνεται ότι εξαρτώνται από συγκεκριμένους θεωρητικούς, οργανωτικούς και τεχνικούς περιορισμούς. Η πειραματική επαλήθευση της μεθοδολογίας επιτυγχάνεται με την κατασκευή και επίδειξη της Διεπαφής Ανακάλυψης Γνώσης (Knowledge Discovery Interface) μιας κατανεμημένης δηλαδή δικτυακής υπηρεσίας, η οποία έχει εφαρμοστεί με επιτυχία σε πειραματικά δεδομένα. Τα αποτελέσματα που προκύπτουν με τη χρήση της διεπαφής επαληθεύουν, μέχρι ορισμένο βαθμό, τις υποθέσεις που έχουν γίνει σχετικά κυρίως με την παράμετρο της εκφραστικότητας και δίνουν το έναυσμα για την αναζήτηση και εξέταση της υποστήριξης των νέων προτεινόμενων επεκτάσεων της λογικής θεωρίας του Σημαντικού Ιστού, δηλαδή της γλώσσας OWL 1.1. Για την ενίσχυση της εκφραστικότητας της ανακάλυψης γνώσης στην περίπτωση συγκεκριμένων πεδίων γνώσης (knowledge domains) εισάγεται μια νέα τεχνική, αποκαλούμενη Σημασιακή Προσαρμογή. Η τεχνική αυτή εξελίσσει την Προσαρμογή Μεταδεδομένων Εφαρμογής (Metadata Application Profiling) από μια επίπεδη συρραφή και συγχώνευση σχημάτων και πεδίων μεταδεδομένων, σε μία ουσιαστική επέκταση και σημασιακή αναγωγή και εμπλουτισμό του αντίστοιχου μοντέλου στο οποίο εφαρμόζεται. Έτσι, η σημασιακή προσαρμογή εξειδικεύει ένα οντολογικό μοντέλο ως προς μια συγκεκριμένη εφαρμογή, όχι απλά με την προσθήκη λεξιλογίου από ετερογενή σχήματα, αλλά μέσω της σημασιακής εμβάθυνσης (semantic intension) και εκλέπτυνσης (semantic refinement) του αρχικού μοντέλου. Η τεχνική αυτή και τα αποτελέσματά της επαληθεύονται πειραματικά με την εφαρμογή στο μοντέλο πληροφοριών πολιτιστικής κληρονομιάς CIDOC-CRM και δείχνεται ότι, με τη χρήση κατάλληλων μεθόδων, η γενική εφαρμοσιμότητα του μοντέλου μπορεί να διαφυλαχθεί. Για να μπορεί όμως η Ανακάλυψη Γνώσης στο Σημαντικό Ιστό να δώσει ικανοποιητικά αποτελέσματα, απαιτούνται όσο το δυνατόν πληρέστερες και αυξημένες περιγραφές των δικτυακών πόρων. Παρόλο που πληροφορίες άμεσα συμβατές με τη λογική θεωρία του Σημαντικού Ιστού δεν είναι ευχερείς, υπάρχει πληθώρα δεδομένων οργανωμένων σε επίπεδα σχήματα μεταδεδομένων (flat metadata schemata). Διερευνάται επομένως αν η SWKD μπορεί να εφαρμοστεί αποδοτικά και εκφραστικά στην περίπτωση τέτοιων ημιδομημένων μοντέλων γνώσης, όπως για παράδειγμα στην περίπτωση του σχήματος μεταδεδομένων Dublin Core. Δείχνεται ότι το πρόβλημα αυτό ανάγεται μερικώς στην εφαρμογή της σημασιακής προσαρμογής στην περίπτωση τέτοιων μοντέλων, ενώ για τη διαφύλαξη της διαλειτουργικότητας και την επίλυση αμφισημιών που προκύπτουν εφαρμόζονται ανάλογες μέθοδοι και επιπλέον εξετάζεται η τεχνική της παρονομασίας (punning) που εισάγει η OWL 1.1, βάσει της οποίας ο ορισμός ενός ονόματος μπορεί να έχει κυμαινόμενη σημασιακή ερμηνεία ανάλογα με τα συμφραζόμενα. Συμπερασματικά, οι νέες μέθοδοι που προτείνονται μπορούν να βελτιώσουν το πρόβλημα της Ανακάλυψης Γνώσης στο Σημαντικό Ιστό ως προς την εκφραστικότητα, ενώ ταυτόχρονα η πολυπλοκότητα παραμένει η μικρότερη δυνατή. Επιτυγχάνουν επίσης την παραγωγή πιο εκφραστικών περιγραφών από υπάρχοντα μεταδεδομένα, προτείνοντας έτσι μια λύση στο πρόβλημα της εκκίνησης (bootstrapping) για το Σημαντικό Ιστό. Παράλληλα, μπορούν να χρησιμοποιηθούν ως βάση για την υλοποίηση πιο αποδοτικών τεχνικών κατανεμημένου και αυξητικού συλλογισμού. / Semantic Web is a combination of technologies and standards in order to give Web information strictly defined semantic structure and meaning. Its aim is to enable Web users and automated agents to process, manage and utilize properly described information in intelligent and efficient ways. Nevertheless, despite the various techniques that have been proposed, there is no clear method such that, by taking advantage of Semantic Web technologies, to be able to retrieve information deductively, i.e. to infer new and implicit information based on explicitly expressed facts. In order to address this situation, the problem of Semantic Web Knowledge Discovery (SWKD) is first specified and introduced. SWKD takes advantage of the semantic underpinnings and semantic descriptions of information, organized in a logic theory (i.e. ontologies expressed in OWL). Through the use of appropriate automated reasoning mechanisms, SWKD makes then possible to deduce new and unexpressed information that is only implied among explicit facts. The question as to whether and to what extent do Semantic Web technologies and logic theory contribute efficiently and expressively enough to the SWKD problem is evaluated through the establishment of a SWKD methodology, which builds upon recent theoretical results, as well as on the qualitative and experimental comparison of some popular inference engines, based on Description Logics. It is shown that the efficiency and expressivity of this method depends on specific theoretical, organizational and technical limitations. The experimental verification of this methodology is achieved through the development and demonstration of the Knowledge Discovery Interface (KDI), a web-distributed service that has been successfully applied on experimental data. The results taken through the KDI confirm, to a certain extent, the assumptions made mostly about expressivity and motivate the examination and investigation of the newly proposed extensions to the Semantic Web logic theory, namely the OWL 1.1 language. In order to strengthen the expressivity of knowledge discovery in the case of particular knowledge domains a new technique is introduced, known as Semantic Profiling. This technique evolves traditional Metadata Application Profiling from a flat aggregation and mixing of schemata and metadata elements to the substantial extension and semantic enhancement and enrichment of the model on which it is applied. Thus, semantic profiling actually profiles an ontological model for a particular application, not only by bringing together vocabularies from disparate schemata, but also through the semantic intension and semantic refinement of the initial model. This technique and its results are experimentally verified through its application on the CIDOC-CRM cultural heritage information model and it is shown that, through appropriate methods, the general applicability of the model can be preserved. However, for SWKD to be of much value, it requires the availability of rich and detailed resource descriptions. Even though information compatible with the Semantic Web logic theory are not always readily available, there are plenty of data organized in flat metadata schemata. To this end, it is investigated whether SWKD can be efficiently and expressively applied on such semi-structured knowledge models, as is the case for example with the Dublin Core metadata schema. It is shown that this problem can be partially reduced to applying semantic profiling on such models and, in order to retain interoperability and resolve potential ambiguities, the OWL 1.1 punning feature is investigated, based on which a name definition may have variable semantic interpretation depending on the ontological context. In conclusion, these newly proposed methods can improve the SWKD problem in terms of expressive strength, while keeping complexity as low as possible. They also contribute to the creation of expressive descriptions from existing metadata, suggesting a solution to the Semantic Web bootstrapping problem. Finally, they can be utilized as the basis for implementing more efficient techniques that involve distributed and incremental reasoning.
527

Weaving the semantic web: Contributions and insights

Cregan, Anne, Computer Science & Engineering, Faculty of Engineering, UNSW January 2008 (has links)
The semantic web aims to make the meaning of data on the web explicit and machine processable. Harking back to Leibniz in its vision, it imagines a world of interlinked information that computers `understand' and `know' how to process based on its meaning. Spearheaded by the World Wide Web Consortium, ontology languages OWL and RDF form the core of the current technical offerings. RDF has successfully enabled the construction of virtually unlimited webs of data, whilst OWL gives the ability to express complex relationships between RDF data triples. However, the formal semantics of these languages limit themselves to that aspect of meaning that can be captured by mechanical inference rules, leaving many open questions as to other aspects of meaning and how they might be made machine processable. The Semantic Web has faced a number of problems that are addressed by the included publications. Its germination within academia, and logical semantics has seen it struggle to become familiar, accessible and implementable for the general IT population, so an overview of semantic technologies is provided. Faced with competing `semantic' languages, such as the ISO's Topic Map standards, a method for building ISO-compliant Topic Maps in the OWL DL language has been provided, enabling them to take advantage of the more mature OWL language and tools. Supplementation with rules is needed to deal with many real-world scenarios and this is explored as a practical exercise. The available syntaxes for OWL have hindered domain experts in ontology building, so a natural language syntax for OWL designed for use by non-logicians is offered and compared with similar offerings. In recent years, proliferation of ontologies has resulted in far more than are needed in any given domain space, so a mechanism is proposed to facilitate the reuse of existing ontologies by giving contextual information and leveraging social factors to encourage wider adoption of common ontologies and achieve interoperability. Lastly, the question of meaning is addressed in relation to the need to define one's terms and to ground one's symbols by anchoring them effectively, ultimately providing the foundation for evolving a `Pragmatic Web' of action.
528

Towards a model for ensuring optimal interoperability between the security systems of trading partners in a business-to-business e-commerce context

Pather, Maree 25 August 2009 (has links)
A vast range of controls/countermeasures exists for implementing security on information systems connected to the Internet. For the practitioner attempting to implement an integrated solution between trading partners operating across the Internet, this has serious implications in respect of interoperability between the security systems of the trading partners. The problem is exacerbated by the range of specification options within each control. This research is an attempt to find a set of relevant controls and specifications towards a framework for ensuring optimal interoperability between trading partners in this context. Since a policy-based, layered approach is advocated, which allows each trading partner to address localized risks independently, no exhaustive risk analysis is attempted. The focus is on infrastructure that is simultaneously optimally secure and provides optimal interoperability. It should also be scalable, allowing for additional security controls to be added whenever deemed necessary. / Computing / M. Sc. (Information Systems)
529

L'espace documentaire en restructuration : l'évolution des services des bibliothèques universitaires. / The information space sstructurde by the digital approach : development of the service offering in academic libraries

Bourdenet, Philippe 05 December 2013 (has links)
Le catalogue occupe une place privilégiée dans l’offre de service des bibliothèques universitaires, pivot de l’intermédiation. Depuis 10 ans, il traverse une crise grave, voyant les usagers le délaisser à la faveur des moteurs de recherche généralistes. Le web, plus qu’un sérieux concurrent, devance aujourd’hui les systèmes d’information documentaires, et devient le point d’entrée principal pour la recherche d’information. Les bibliothèques tentent de structurer un espace documentaire qui soit habité par les usagers, au sein duquel se développe l’offre de service, mais celle-ci se présente encore comme une série de silos inertes, sans grande possibilité de navigation, malgré de considérables efforts d’ingénierie et des pistes d’évolution vers les outils de découverte. La profession, consciente de cette crise profonde, après avoir accusé les remous occasionnés par la dimension disruptive du numérique, cherche des moyens pour adapter et diversifier son offre, fluidifier la diffusion de l’information, et se réinvente un rôle d’intermédiation en cherchant à tirer profit des nouvelles pratiques des usagers, de leurs nouvelles attentes, et de nouvelles perspectives. Les bibliothèques placent leur espoir dans de nouveaux modèles de données, tentent d’y ajouter un niveau d’abstraction favorisant les liaisons avec l’univers de la connaissance. L’évolution vers le web sémantique semble une opportunité à saisir pour valoriser les collections et les rendre exploitables dans un autre contexte, au prix d’importants efforts que cette analyse tente de mesurer. Une approche constructiviste fondée sur l’observation participante et le recueil de données offre une vision issue de l’intérieur de la communauté des bibliothèques sur l’évolution des catalogues et des outils d’intermédiation, et ouvre des perspectives sur leurs enjeux. / The catalog takes up a special position in the supply of services of academic libraries, as a pivot for the intermediary between users and information professionals who carry the responsibility for building up collections. For 10 years, through a serious crisis, they’ve been seeing their patrons preferring the general or commercial search engines. The Web is more than a serious competitor today, ahead of the document information systems, and became the main access point for information retrieval. Libraries are trying to structure an information space that is temporarily or permanently inhabited by users, in which the service offering is developed, but it is still presented as a series of silos, with few opportunities of navigation between them despite considerable engineering efforts and a perspective of evolution towards discovery tools. The profession, having become aware of this deep crisis after accusing eddies caused by the breakdown of the digital switch, looking for ways to adapt and diversify its offering, streamlines the dissemination of information, and reinvents its roles, trying to take advantage of new practices of users, new expectations and new prospects. Libraries put their hope in new data models, trying to add a level of abstraction promoting links with the world of knowledge. The evolution towards the Semantic Web seems to be a valuable opportunity to enhance the collections and make them usable in another context, at the expense of significant efforts sized up by this analysis. A constructivist approach based on participant observation and data collection offers a vision of the outcome within the library community on the development of catalogs and intermediation tools, and an outlook on their issues.
530

CNC-C2: um controlador aderente às normas ISO 14649 E IEC 61499 / CNC-C2: um controlador aderente às normas ISO 14649 e IEC 61499

Harbs, Eduardo 09 October 2012 (has links)
Made available in DSpace on 2016-12-12T17:38:31Z (GMT). No. of bitstreams: 1 Eduardo Harbs.pdf: 12792734 bytes, checksum: b505810b68894ae2924a805e7f89d032 (MD5) Previous issue date: 2012-10-09 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The industry has found difficulties towards CNC machines flexibility, due to the CNC programming current standard, the ISO 6983 or G/M code. The ISO 14649 or STEP-NC was developed to replace the current standard. It is a new unified data transfer model between CAD/CAM and CNC systems. To satisfy the new automation and control systems requirements, the IEC 61499 standard was developed, aiming the use of software objects, called function blocks (FBs). In this work, the standards STEP-NC and IEC 61499 were integrated to build a new generation of CNC, where STEP-NC supplies the complete data model without functionality, and the FBs provide the functionalities to the data model for the machine tool command. In this context, a controller for a CNC machine prototype, compliant to STEP-NC and IEC 61499 standards was developed. The prototype consists of a 2,5D milling machine, driven by a group of three servomotors drivers with integrated PLCs. A set of software was developed for compiling STEP-NC files and the automatic generation of IEC 61499 models, viewing, editing and executing FBs and FB networks, and further a library with IEC 61499 models. Test on software and prototype was performed machining an example workpiece, achieving the proposed goal and providing the individual characteristics of the standards in the controller, such as: interoperability, portability, use of features, configurability, distribution and adaptability. / A indústria tem enfrentado dificuldades quanto à flexibilidade das máquinas CNC, devido à norma utilizada atualmente para a programação CNC, a ISO 6983 ou código G/M. Com objetivo de substituição desta norma, desenvolveu-se a ISO 14649 ou STEP-NC, que é um novo modelo de transferência de dados unificado entre sistemas CAD/CAM e CNC. Para atender os novos requisitos de automação e controle de sistemas, desenvolveu-se a norma IEC 61499, visando o uso de objetos de software, os function blocks (FBs). Neste trabalho integraram-se as normas STEP-NC e IEC 61499 para a construção de uma nova geração de CNCs, onde STEP-NC fornece o modelo de dados completo, porém sem funcionalidade, e os FBs fornecem as funcionalidades ao modelo de dados para o controle da máquina-ferramenta. Para tal, foi desenvolvido um controlador para uma máquina CNC protótipo aderente às normas STEP-NC e IEC 61499. Este protótipo é constituído de uma fresadora 2,5D, acionada por um conjunto de três servoacionamentos com CLPs integrados. Um conjunto de software foi desenvolvido para compilação do arquivo STEP-NC e geração automática de modelos IEC 61499, visualização, edição e execução de FBs e rede de FBs além de uma biblioteca de modelos IEC 61499. Teste do software e do protótipo foi realizado com a usinagem de uma peça exemplo, alcançando o objetivo proposto e provendo as características individuais das normas no controlador, como: interoperabilidade, portabilidade, uso de features, configurabilidade, distribuição e adaptabilidade.

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