11 research outputs found

    Smart Wireless Sensor Networks

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    The recent development of communication and sensor technology results in the growth of a new attractive and challenging area - wireless sensor networks (WSNs). A wireless sensor network which consists of a large number of sensor nodes is deployed in environmental fields to serve various applications. Facilitated with the ability of wireless communication and intelligent computation, these nodes become smart sensors which do not only perceive ambient physical parameters but also be able to process information, cooperate with each other and self-organize into the network. These new features assist the sensor nodes as well as the network to operate more efficiently in terms of both data acquisition and energy consumption. Special purposes of the applications require design and operation of WSNs different from conventional networks such as the internet. The network design must take into account of the objectives of specific applications. The nature of deployed environment must be considered. The limited of sensor nodes� resources such as memory, computational ability, communication bandwidth and energy source are the challenges in network design. A smart wireless sensor network must be able to deal with these constraints as well as to guarantee the connectivity, coverage, reliability and security of network's operation for a maximized lifetime. This book discusses various aspects of designing such smart wireless sensor networks. Main topics includes: design methodologies, network protocols and algorithms, quality of service management, coverage optimization, time synchronization and security techniques for sensor networks

    An adaptive threshold energy detection technique with noise variance estimation for cognitive radio sensor networks

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    The paradigm of wireless sensor networks (WSNs) has gained a lot of popularity in the recent years due to the proliferation of wireless devices. This is evident as WSNs find numerous application areas in fields such as agriculture, infrastructure monitoring, transport, and security surveillance. Traditionally, most deployments of WSNs operate in the unlicensed industrial scientific and medical (ISM) band and more specifically, the globally available 2.4 GHz frequency band. This band is shared with several other wireless technologies such as Bluetooth, Wi-Fi, near field communication and other proprietary technologies thus leading to overcrowding and interference problems. The concept of dynamic spectrum access alongside cognitive radio technology can mitigate the coexistence issues by allowing WSNs to dynamically access new spectrum opportunities. Furthermore, cognitive radio technology addresses some of the inherent constraints of WSNs thus introducing a myriad of benefits. This justifies the emergence of cognitive radio sensor networks (CRSNs). The selection of a spectrum sensing technique plays a vital role in the design and implementation of a CRSN. This dissertation sifts through the spectrum sensing techniques proposed in literature investigating their suitability for CRSN applications. We make amendments to the conventional energy detector particularly on the threshold selection technique. We propose an adaptive threshold energy detection model with noise variance estimation for implementation in CRSN systems. Experimental work on our adaptive threshold technique based on the recursive one-sided hypothesis test (ROHT) technique was carried out using MatLab. The results obtained indicate that our proposed technique is able to achieve adaptability of the threshold value based on the noise variance. We also employ the constant false alarm rate (CFAR) threshold to act as a defence mechanism against interference of the primary user at low signal to noise ratio (SNR). Our evaluations indicate that our adaptive threshold technique achieves double dynamicity of the threshold value based on the noise variance and the perceived SNR

    Applications of wireless sensor technologies in construction

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    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

    Engineering and built environment project conference 2016: book of abstracts - Toowoomba, Australia, 19-23 September 2016

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    Book of Abstracts of the USQ Engineering and Built Environment Conference 2016, held Toowoomba, Australia, 19-23 September 2016. These proceedings include extended abstracts of the verbal presentations that are delivered at the project conference. The work reported at the conference is the research undertaken by students in meeting the requirements of courses ENG4111/ENG4112 Research Project for undergraduate or ENG8411/ENG8412 Research Project and Dissertation for postgraduate students

    31th International Conference on Information Modelling and Knowledge Bases

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    Information modelling is becoming more and more important topic for researchers, designers, and users of information systems.The amount and complexity of information itself, the number of abstractionlevels of information, and the size of databases and knowledge bases arecontinuously growing. Conceptual modelling is one of the sub-areas ofinformation modelling. The aim of this conference is to bring together experts from different areas of computer science and other disciplines, who have a common interest in understanding and solving problems on information modelling and knowledge bases, as well as applying the results of research to practice. We also aim to recognize and study new areas on modelling and knowledge bases to which more attention should be paid. Therefore philosophy and logic, cognitive science, knowledge management, linguistics and management science are relevant areas, too. In the conference, there will be three categories of presentations, i.e. full papers, short papers and position papers

    New Approach of Indoor and Outdoor Localization Systems

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    Accurate determination of the mobile position constitutes the basis of many new applications. This book provides a detailed account of wireless systems for positioning, signal processing, radio localization techniques (Time Difference Of Arrival), performances evaluation, and localization applications. The first section is dedicated to Satellite systems for positioning like GPS, GNSS. The second section addresses the localization applications using the wireless sensor networks. Some techniques are introduced for localization systems, especially for indoor positioning, such as Ultra Wide Band (UWB), WIFI. The last section is dedicated to Coupled GPS and other sensors. Some results of simulations, implementation and tests are given to help readers grasp the presented techniques. This is an ideal book for students, PhD students, academics and engineers in the field of Communication, localization & Signal Processing, especially in indoor and outdoor localization domains

    Alterity and metafiction: poetic design in the work of Michael Ondaatje

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    Estudia la literatura canadiense anglófona de las últimas décadas centrándose en el poeta y novelista Michael Ondaadtje (1943- ), desde la publicación de su primer libro en 1967 hasta su última novela publicada en el año 2000. Se estudia tanto la literatura como la cultura contemporánea desde un punto de vista interdisciplinar

    Maritime expressions:a corpus based exploration of maritime metaphors

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    This study uses a purpose-built corpus to explore the linguistic legacy of Britain’s maritime history found in the form of hundreds of specialised ‘Maritime Expressions’ (MEs), such as TAKEN ABACK, ANCHOR and ALOOF, that permeate modern English. Selecting just those expressions commencing with ’A’, it analyses 61 MEs in detail and describes the processes by which these technical expressions, from a highly specialised occupational discourse community, have made their way into modern English. The Maritime Text Corpus (MTC) comprises 8.8 million words, encompassing a range of text types and registers, selected to provide a cross-section of ‘maritime’ writing. It is analysed using WordSmith analytical software (Scott, 2010), with the 100 million-word British National Corpus (BNC) as a reference corpus. Using the MTC, a list of keywords of specific salience within the maritime discourse has been compiled and, using frequency data, concordances and collocations, these MEs are described in detail and their use and form in the MTC and the BNC is compared. The study examines the transformation from ME to figurative use in the general discourse, in terms of form and metaphoricity. MEs are classified according to their metaphorical strength and their transference from maritime usage into new registers and domains such as those of business, politics, sports and reportage etc. A revised model of metaphoricity is developed and a new category of figurative expression, the ‘resonator’, is proposed. Additionally, developing the work of Lakov and Johnson, Kovesces and others on Conceptual Metaphor Theory (CMT), a number of Maritime Conceptual Metaphors are identified and their cultural significance is discussed
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