19 research outputs found

    The effects of network factors on the performance of 3G UMTS applications

    Get PDF
    Includes bibliographical references (leaves 139-148).3G is the wireless network technology expected to allow wireless applications to perform on par with wired applications. However 3G has factors which limit its performance. These factors include both device factors such as small screens, limited battery power and life, as well as network factors such as high delay networks and low bandwidths. This thesis investigates the following: how network factors affect the performance of 3G UMTS applications; which network factors have the most significant impact on a specific application; whether there are any minimum requirements needed for an application. Eight popular 3G applications were investigated: FTP, email, MMS, SMS, HTTP web browsing, broadcast media, video calling and streaming media

    Automatic translation of formal data specifications to voice data-input applications.

    Get PDF
    This thesis introduces a complete solution for automatic translation of formal data specifications to voice data-input applications. The objective of the research is to automatically generate applications for inputting data through speech from specifications of the structure of the data. The formal data specifications are XML DTDs. A new formalization called Grammar-DTD (G-DTD) is introduced as an extended DTD that contains grammars to describe valid values of the DTD elements and attributes. G-DTDs facilitate the automatic generation of Voice XML applications that correspond to the original DTD structure. The development of the automatic application-generator included identifying constraints on the G-DTD to ensure a feasible translation, using predicate calculus to build a knowledge base of inference rules that describes the mapping procedure, and writing an algorithm for the automatic translation based on the inference rules.Dept. of Computer Science. Paper copy at Leddy Library: Theses & Major Papers - Basement, West Bldg. / Call Number: Thesis2006 .H355. Source: Masters Abstracts International, Volume: 45-01, page: 0354. Thesis (M.Sc.)--University of Windsor (Canada), 2006

    Protection concepts in distribution networks with decentralised energy resources

    Get PDF
    Die stetig steigende Anbindung von dezentralen Energieerzeugern (DER) an Mittel- (MS) und Niederspannungsnetze (NS) fordert eine Analyse der bestehenden Netzschutzkonzepte. Die Beeinflussung der Netzschutzkonzepte ist abhĂ€ngig davon, wie die DER an das Mittelspannungsnetz angebunden sind. Die vorliegende Arbeit konzentriert sich auf die Analyse von Beeinflussungen durch kleine DER, die an das Mittelspannungsnetz ĂŒber einen Umrichter angebunden sind. Das erste Problem, das in dieser Arbeit untersucht ist, ist die Beeinflussung der unterschiedlichen Schutzalgorithmen durch hohe Anteile von Harmonischen. Diese werden verursacht durch die steigende Zahl elektrischer GerĂ€te, sowohl auf der Verbraucherseite als auch auf der Seite der Energieerzeuger. Die Beeinflussung, entsprechend der Norm IEC 61000-3–2, wurde an unterschiedlichen Typen von Netzschutzsystemen untersucht. Die getesteten Distanzschutzalgorithmen basierten auf konventionellen Methoden zu Berechnung der Impedanz wie: SinusAlgorithmen, Algorithmen basierend auf der Leitungs-Differentialgleichung erster oder zweiter Ordnung, Filteralgorithmen fĂŒr Berechnung komplexer Zeiger, und Algorithmen, die auf kĂŒnstliche Intelligenz basieren, wie harmonisch aktivierte neuronale Netze. Die unterschiedlichen Typen von Netzschutzprinzipien, die untersucht wurden sind: Überstrom, Distanz und Differenzial. Einige Untersuchungen wurden auch im Netzschutzlabor der UniversitĂ€t durchgefĂŒhrt. Bei beiden Tests konnte nachgewiesen werden, dass die heutigen state-of-the-art Netzschutzsysteme durch Harmonische entsprechend IEC 61000-3–2, praktisch nicht beeinflusst werden. Der zweite Problemkreis der in dieser Arbeit diskutiert wird sind die Anforderungen, welche die Anbindung von DER an das Netz, an moderne Netzschutzsysteme stellen. Einige Beispiele illustrieren die Lage der Energieversorgung der Zukunft und zeigen SelektivitĂ€tsprobleme auf, sollten nur konventionelle Netzschutzsysteme benutzt werden. In dieser Arbeit wird ein neues Schutzkonzept fĂŒr Mittelspannungsnetze mit hohem Anteil an DER vorgestellt und analysiert. Das Konzept beruht auf der neuen Norm fĂŒr „Substation Automatisation System - IEC 61850“ und einem Netzschutz-Managementsystem. Die Methode der zusĂ€tzlichen Signal-Einspeisung wurde ebenfalls vorgestellt. Die Basis eines effizienten Netzschutz-Managementsystems ist das Wissen vom Verhalten des Systems in normalen Betrieb und unter Fehlerbedingungen. Die Computer- und Internettechnologie, die moderne Kommunikation, der interdisziplinĂ€re Datenaustausch stellen ganz neue Anforderungen an die Wissensbasis energietechnischer Ingenieure. Mit dem Ziel neue Medien in der Ingenieurausbildung einzusetzen ist, im Rahmen dieser Arbeit ein E-learning Kurs entwickelt worden. Dabei ermöglicht das Internet neue Methoden zur Wissensvermittlung zu entwickeln. Die UnabhĂ€ngigkeit von Zeit und Ort, die große Anzahl von Lehrmöglichkeiten und die Online-Diskussionen sind nur einige zu nennende Vorteile. In dieser Arbeit ist die Idee zur Realisierung sowie Ergebnisse des E-learning Kurses im Bereich digitaler Netzschutztechnik, als Erweiterung der konventionellen Lehrveranstaltung prĂ€sentiert worden. Dieser Kurs wird den Studenten der UniversitĂ€t in einem speziell gestalteten Multimedialabor angeboten. Es besteht via Internet die Möglichkeit den Kurses z.B. zu Hause zur Wiederholung und PrĂŒfungsvorbereitung nochmals zu bearbeiten.    The continuously rising implementation of DER in the distribution network requests analyses of the present network protection concepts. Depending on the type of connection to the network, the influences of the DER on the network protection systems vary. This dissertation concentrates on the analyses of the influence of implementation of small DER, which are connected to the network via an inverter. The first problem discussed in this dissertation is the influence of high level of harmonics on the protection devices. The rising implementation of power electronic devices into the network, both on the side of the energy generation and energy consumption, leads to a high level of injected harmonics into the network. The influence of a high amount of harmonics, according to the Standard IEC 61000-3–2, on different types of algorithms implemented in different types of protection devices was investigated using a test network. The tested algorithms implemented in the distance protection devices were based on conventional methods such as steady state algorithms, algorithms using the differential equation of first or second order written for the protected line, algorithms based on the filter approach, and on the “new” methods using artificial intelligence i.e.: parametrical estimation and harmonic activated neuronal networks. The different types of protection devices that were investigated were based on the principle of over-current (definite-current and inverse time), distance and differential. Some of the tests were conducted in the protection technique laboratory at the university. From both tests (simulation and practical) it is concluded that the state-of-the-art protection devices are insensitive to harmonics according to the allowed level by the standard IEC 61000-3–2. The tendency of today’s protection technology engineers lies in searching for ways to shorten of the calculation time of the algorithms. The second problem discussed is the challenge set to the network protection systems in the distribution networks with implemented DER. A few examples illustrate the situation of the energy supply of the future illustrate the problems of lack of protection with the present protection concepts. In this sense, this work presents and analyses a protectionconcept in distribution networks with DER, using the substation automation system and the protection management system based on the new standard IEC 61850 for communication networks in substations. The method of using an additional signal injection as additional criteria for the presented network protection concept is also discussed. The basis for efficient protection system management is the knowledge of power system performance under fault and normal operation (service) conditions as well as the switchgear interfaces. This requires a proper knowledge of power system engineering. With a changeable power system infrastructure, the protection system management becomes a real challenge to the network protection experts. Computer- and internet technology, modern serial communications, sharing of data with other disciplines and a trend towards system engineering require a broader knowledge and close co-operation with others, beside the protection system engineers. With the goal of spreading the knowledge of network protection systems, in the frames of this work a special e-learning course was realised. The internet provides new possibilities for gaining and spreading knowledge. The time and place independence, the high amount of possibilities for knowledge sources and on line discussions are just a few of the possibilities. In this work, the idea, the realisation and the implementation of this new way of teaching and studying digital network protection alongside the conventional way are presented as well. An importance is also given to the feed back of the user of the e-learning course. This course is offered to the students at the university in a specially realised multimedia laboratory and used for gaining knowledge in the area of network protection technique. The possibility of using the course at home for re-capitulation of the taught material and for self-test is also possible, by simply logging on to the e-learning course. This course could also be used by engineers who want to refresh their knowledge in the form of a fast (self) training.   &nbsp

    Applications of wireless sensor technologies in construction

    Get PDF
    The construction industry is characterised by a number of problems in crucial fields such as health, safety and logistics. Since these problems affect the progress of construction projects, the construction industry has attempted to introduce the use of innovative information and communication technologies on the construction site. Specific technologies which find applicability on the construction site are wireless sensors, and especially radio-frequency identification (RFID) technology. RFID tagging is a technology capable of tracking items. The technology has been applied on the construction site for various applications, such as asset tracking. There are many problems related to health, safety and logistics on the construction site which could be resolved using RFID technology. In the health and safety field, the problems which exist are the monitoring of dangerous areas on the construction site, such as large excavation areas, the collisions between workers and vehicles, between vehicles and equipment and between vehicles, the detection of hazardous substances on the construction site when the construction work has been completed and the collection of hazard notifications from specific areas of the construction site as feedback for the prevention of future accidents. In the logistics field, the tracking of a material during its delivery on the construction site, its transportation to specific subcontractors and its future utilisation as well as the monitoring of the rate of use of materials on the construction site, the checking of the sequence of steel members and the monitoring of the temperature of porous materials are issues which can be realised using RFID technology. In order to facilitate the use of RFID technology for the specific health, safety and logistics problems, a system has been developed. The operation of this system is based on the combined use of hardware and software elements. The hardware elements of the developed system are a wireless local area network, RFID readers and tags. Its software elements are a software development kit based on which, a number of graphical user interfaces have been created for the interaction of the users with the REID tags, and Notepad files which store data collected from REID tags through the graphical user interfaces. Each of the graphical user interfaces is designed in such a way so that it corresponds to the requirements of the health, safety or logistics situation in which it is used. The proposed system has been tested on a simulated construction site by a group of experts and a number of findings have been produced. Specifically, the testing of the proposed system showed that RFID technology can connect the different stages which characterise the construction supply chain. In addition, it showed the capability of the technology to be integrated with construction processes. The testing of the system also revealed the barriers and the enablers to the use of RFID technology in the construction industry. An example of such a barrier is the unwillingness of the people of the construction industry to quit traditional techniques in favour of a new technology. Enablers which enhance the use of RFID technology in the construction industry are the lack of complexity which characterises the operation of RFID tagging and the relatively low cost of RFID tags. In general, RFID technology is an innovative sensor technology which can help the construction industry through its asset tracking ability. However, further research should be done on the improvement of RFID technology on specific characteristics, such as its inability to provide location coordinates and the resilience of the electromagnetic signal emitted by the RFID reader when there are metallic objects around the reader

    Mediated discourse at the European Parliament: Empirical investigations

    Get PDF
    The purpose of this book is to showcase a diverse set of directions in empirical research on mediated discourse, reflecting on the state-of-the-art and the increasing intersection between Corpus-based Interpreting Studies (CBIS) and Corpus-based Translation Studies (CBTS). Undeniably, data from the European Parliament (EP) offer a great opportunity for such research. Not only does the institution provide a sizeable sample of oral debates held at the EP together with their simultaneous interpretations into all languages of the European Union. It also makes available written verbatim reports of the original speeches, which used to be translated. From a methodological perspective, EP materials thus guarantee a great degree of homogeneity, which is particularly valuable in corpus studies, where data comparability is frequently a challenge. In this volume, progress is visible in both CBIS and CBTS. In interpreting, it manifests itself notably in the availability of comprehensive transcription, annotation and alignment systems. In translation, datasets are becoming substantially richer in metadata, which allow for increasingly refined multi-factorial analysis. At the crossroads between the two fields, intermodal investigations bring to the fore what these mediation modes have in common and how they differ. The volume is thus aimed in particular at Interpreting and Translation scholars looking for new descriptive insights and methodological approaches in the investigation of mediated discourse, but it may be also of interest for (corpus) linguists analysing parliamentary discourse in general

    Empirical investigations

    Get PDF
    The purpose of this book is to showcase a diverse set of directions in empirical research on mediated discourse, reflecting on the state-of-the-art and the increasing intersection between Corpus-based Interpreting Studies (CBIS) and Corpus-based Translation Studies (CBTS). Undeniably, data from the European Parliament (EP) offer a great opportunity for such research. Not only does the institution provide a sizeable sample of oral debates held at the EP together with their simultaneous interpretations into all languages of the European Union. It also makes available written verbatim reports of the original speeches, which used to be translated. From a methodological perspective, EP materials thus guarantee a great degree of homogeneity, which is particularly valuable in corpus studies, where data comparability is frequently a challenge. In this volume, progress is visible in both CBIS and CBTS. In interpreting, it manifests itself notably in the availability of comprehensive transcription, annotation and alignment systems. In translation, datasets are becoming substantially richer in metadata, which allow for increasingly refined multi-factorial analysis. At the crossroads between the two fields, intermodal investigations bring to the fore what these mediation modes have in common and how they differ. The volume is thus aimed in particular at Interpreting and Translation scholars looking for new descriptive insights and methodological approaches in the investigation of mediated discourse, but it may be also of interest for (corpus) linguists analysing parliamentary discourse in general

    Identification and characterisation of spindle checkpoint silencing factors in Schizosaccharomyces pombe

    Get PDF
    In cell division, the spindle-assembly checkpoint (SAC) is an important mechanism which ensures proper segregation of chromosomes into daughter cells by delaying anaphase onset until all chromosomes are correctly attached to the mitotic spindle via their kinetochores. This reduces the risk of aneuploidy, which is associated with severe consequences such as birth defects and cancer. Once all kinetochores have been properly attached the SAC is rapidly silenced, allowing the cell to progress through anaphase. Several SAC silencing factors have been identified to date but the mechanisms by which silencing occurs remain unclear. This project aims to improve our understanding of SAC silencing mechanisms by identifying factors involved in this process and characterising their functions. High-throughput genetic screening was carried out in fission yeast (Schizosaccharomyces pombe) to identify silencing defective mutants. In designing this genetic screen, we aimed to improve upon previous screens by avoiding false positives due to mutations that lead to prolonged mitotic arrest for reasons unrelated to checkpoint silencing defects, e.g. disruption of kinetochore function. To achieve this, an ectopic synthetic checkpoint mechanism developed as part of previous work in the lab was used to spatially separate checkpoint activation from the kinetochore (Yuan et al, 2016). This screening approach has produced a list of candidates. Assays to confirm and characterise the checkpoint silencing roles of a subset of these factors have been carried out. These factors were selected on the basis of strength of phenotype in the screen and include SWI/SNF component Sol1 and golgi-associated protein Grh1, among others. Additionally, work was carried out to characterise a previously identified checkpoint silencing factor, Protein Phosphatase 1 (PP1) Dis2 in a synthetic ectopic checkpoint arrest (SynCheckABA). This work illustrated the suitability of this synthetic system as a tool for further study of SAC silencing (Amin et al, 2019)

    Building the Future Internet through FIRE

    Get PDF
    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate

    Building the Future Internet through FIRE

    Get PDF
    The Internet as we know it today is the result of a continuous activity for improving network communications, end user services, computational processes and also information technology infrastructures. The Internet has become a critical infrastructure for the human-being by offering complex networking services and end-user applications that all together have transformed all aspects, mainly economical, of our lives. Recently, with the advent of new paradigms and the progress in wireless technology, sensor networks and information systems and also the inexorable shift towards everything connected paradigm, first as known as the Internet of Things and lately envisioning into the Internet of Everything, a data-driven society has been created. In a data-driven society, productivity, knowledge, and experience are dependent on increasingly open, dynamic, interdependent and complex Internet services. The challenge for the Internet of the Future design is to build robust enabling technologies, implement and deploy adaptive systems, to create business opportunities considering increasing uncertainties and emergent systemic behaviors where humans and machines seamlessly cooperate

    Towards lightweight, low-latency network function virtualisation at the network edge

    Get PDF
    Communication networks are witnessing a dramatic growth in the number of connected mobile devices, sensors and the Internet of Everything (IoE) equipment, which have been estimated to exceed 50 billion by 2020, generating zettabytes of traffic each year. In addition, networks are stressed to serve the increased capabilities of the mobile devices (e.g., HD cameras) and to fulfil the users' desire for always-on, multimedia-oriented, and low-latency connectivity. To cope with these challenges, service providers are exploiting softwarised, cost-effective, and flexible service provisioning, known as Network Function Virtualisation (NFV). At the same time, future networks are aiming to push services to the edge of the network, to close physical proximity from the users, which has the potential to reduce end-to-end latency, while increasing the flexibility and agility of allocating resources. However, the heavy footprint of today's NFV platforms and their lack of dynamic, latency-optimal orchestration prevents them from being used at the edge of the network. In this thesis, the opportunities of bringing NFV to the network edge are identified. As a concrete solution, the thesis presents Glasgow Network Functions (GNF), a container-based NFV framework that allocates and dynamically orchestrates lightweight virtual network functions (vNFs) at the edge of the network, providing low-latency network services (e.g., security functions or content caches) to users. The thesis presents a powerful formalisation for the latency-optimal placement of edge vNFs and provides an exact solution using Integer Linear Programming, along with a placement scheduler that relies on Optimal Stopping Theory to efficiently re-calculate the placement following roaming users and temporal changes in latency characteristics. The results of this work demonstrate that GNF's real-world vNF examples can be created and hosted on a variety of hosting devices, including VMs from public clouds and low-cost edge devices typically found at the customer's premises. The results also show that GNF can carefully manage the placement of vNFs to provide low-latency guarantees, while minimising the number of vNF migrations required by the operators to keep the placement latency-optimal
    corecore