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A conceptual model with wireless and mobile techniques is developed in this thesis for remote real-time condition monitoring, which is applied for monitoring, diagnosing, and controlling the working conditions of machines. The model has the following major functions: data acquisition, data processing, decision making, and remote communication. The data acquisition module is built up within this model using the sensory technique and data I/O interfaces to acquire the working conditions data of a machine and extract the physical information about the machine (e.g. failure, wear, etc.) for data processing and decision making. The data processing is conducted using digital conversion and feature extraction to process the received analogue condition data and convert the data into the physical quantities of working condition of the machine for sequent fault diagnosis. A real-time fault diagnostic scheme for decision-making is applied based on digital filtering and pattern classification to real-time identify the fault symptom of the machine and provide advice for decision making for maintenance. Process control is implemented to control the operation status of the machine automatically, inform the maintenance personnel diagnostic results and alert the working conditions of the machine. Remote communication with wireless and mobile features greatly advance the machine’s condition monitoring technology with real-time fault diagnostic capacity, by providing a wireless-based platform to enable the implementation of data acquisition, real-time fault diagnosis, and decision making through the Internet, wireless, and mobile phone network. The model integrating above techniques and methods has been applied into the following three areas: (1) Development of a Remote Real-time Condition Monitoring System of Industrial Gearbox, supported by the Stimulation Innovation Success programme (2007-2008); (2) Development of a Remote Control System of Solid Desiccant Dehumidifier for Air Conditioning in Low Carbon Emission Buildings, supported by the Sustainable Construction iNET programme (2009-2010); (3) Development of an Innovative Remote Monitoring System of Thermo-Electric-Generations, supported by the Sustainable Construction iNET programme (2010-2011). The combination of wireless and mobile techniques with data acquisition, real-time fault diagnosis, and decision-making, into a model for remote real-time condition monitoring is a novel contribution to this area.

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The proliferation of mobile devices over the past several years has created a whole new world of the Internet. The deluge of applications for every aspect of today's life has raised the expectation of having ubiquitous connectivity, with a desired Quality of Service (QoS). However, it has violated the original Internet design which was not intended to support mobility, neither better than best-effort delivery. The problem of end-to-end QoS provisioning has been an active area of research for many years. While designed for fixed networks, the use of QoS protocols in IP-based mobile networks, where hosts dynamically change their point of attachments, imposes new challenges to be studied and analysed. Furthermore, a massive growth in the backbone network traffic with its highly unpredictable nature can cause bottlenecks in some links while others are under-utilised, and therefore, breaching the QoS provisioning commitments. The research presented here proposes a new end-to-end QoS mechanism for mobile networks. The scheme is composed of two different approaches for QoS provisioning in access and backbone networks. Firstly, a new scheme is proposed to minimise the signalling overhead, as well as how the QoS is interrupted at the time of handover. By virtue of a developed analytical framework and simulation scenario, the performance of the scheme is investigated thoroughly, emphasising on the figures of merits that affect the efficiency of using QoS signalling protocols in access networks. Secondly, a new QoS-aware routing mechanism is proposed for backbone networks, intending to minimise the congestion on the links while complying traffic requirement. The developed optimisation framework shows that the scheme can achieve near-optimal link utilisation, even under sudden traffic spikes, while complying with traffic needs.

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In response to the arrival of new Web/Internet environments, one of the most attractive challenges in current research is to exploit wireless computing technologies in collaborative product design, and hence to build a ubiquitous mobile information system to enable the collaborative product design within a mobile environment. However, the literature review reveals that although the progress of mobile technologies on wireless networks has largely changed the way people access the Internet; little has been achieved in mobile computing for collaborative product design. The reason is that, due to the distinct features of mobile devices and wireless networks (such as small display screen, limited bandwidth, unreliability of wireless networks, etc.), the methodologies and technologies used in stationary networks are not always applicable to mobile systems. The aim of this research is to establish a Wireless Internet-based Collaborative Working Environment for product design through the combination of multiple technologies, by including: Web services, Parametric Design, the Semantic Web, Agent and Flex Technologies. In order to create, deploy, and manage the distributed resources, Web service is used to implement design resource integration in a platform-independent manner. In addition, Semantic Web Technology is used to create a general knowledge base. This approach includes two components: (1) ontology is used to represent abstract views of product data and (2) added semantic rules are also used to represent relationships among product data. Therefore, an ontology-based description model is thus proposed to facilitate expression and organisation of product information in order to manage and deploy the distributed design resources. This research presents a mobile agent system for collaborative design, supporting the construction of mobile agents which can migrate and access the distributed design resources. After that, in order to resolve the Mobile Platform Compatibility problem, this research presents the most recent Flex technology to enable the mobile applications to be implemented on the different mobile devices; furthermore, with the support of combined Flex technology and Web service, remote users are able to invoke a large-scale computing program via mobile Web browser. The combination of all these technologies provides the cornerstone and effective support in building scalable, extensible interactive mobile systems for collaborative design, as illustrated and demonstrated in this thesis.

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Digital wireless channels are extremely prone to errors that appear in bursts or clusters. Error models characterise the statistical behaviour of bursty profiles derived from digital wireless channels. Generative error models also utilise those bursty profiles in order to create alternatives, which are more efficient for experimental purposes. Error models have a tremendous value for wireless systems. They are useful for the design and performance evaluation of error control schemes, in addition to higher layer protocols in which the statistical properties of the bursty profiles are greatly functional. Furthermore, underlying wireless digital channels can be substituted by generated error profiles. Consequently, computational load and simulation time can be significantly reduced when executing experiments and performing evaluation simulations for higher layer communications protocols and error control strategies. The burst error statistics are the characterisation metrics of error models. These statistics include: error-free run distribution; error-free burst distribution; error burst distribution; error cluster distribution; gap distribution; block error probability distribution; block burst probability distribution; bit error correlation function; normalised covariance function; gap correlation function; and multigap distribution. These burst error statistics scrutinise the error models and differentiate between them, with regards to accuracy. Moreover, some of them are advantageous for the design of digital components in wireless communication systems. This PhD thesis aims to develop accurate and efficient error models and to find applications for them. A thorough investigation has been conducted on the burst error statistics. A breakdown of this thesis is presented as follows. Firstly, an understanding of the different types of generative error models, namely, Markovian based generative models, context-free grammars based generative models, chaotic models, and deterministic process based generative models, has been presented. The most widely used models amongst the generative models have been compared with each other consulting the majority of burst error statistics. In order to study generative error models, error burst profiles were obtained mainly from the Enhanced General Packet Radio Service (EGPRS) system and also the Long Term Evolution (LTE) system. Secondly, more accurate and efficient generative error models have been proposed. Double embedded processes based hidden Markov model and three-layered processes based hidden Markov model have been developed. The two types of error profiles, particularly the bit-level and packet-level error profiles were considered. Thirdly, the deterministic process based generative models’ parameters have been tuned or modified in order to generate packet error sequences rather than only bit error sequences. Moreover, a modification procedure has been introduced to the same models to enhance their generation process and to make them more desirable. Fourthly, adaptive generative error models have been built in order to accommodate widely used generative error models to different digital wireless channels with different channel conditions. Only a few reference error profiles have been required in order to produce additional error profiles in various conditions that are beneficial for the design and performance evaluation of error control schemes and higher layer protocols. Finally, the impact of the Hybrid Automatic Repeat reQuest (HARQ) on the burst error statistics of physical layer error profiles has been studied. Moreover, a model that can generate predicted error sequences with burst error statistics similar to those of error profiles when HARQ is included has been proposed. This model is constructive in predicting the behaviour of the HARQ in terms of a set of higher order statistics rather than only predicting a first order statistic. Moreover, the whole physical layer is replaced by adaptively generated error profiles in order to check the performance of the HARQ protocol. The developed generative error models as well as the developed adaptive generative error models are expected to benefit future research towards the testing of many digital components in the physical layer as well as the wireless protocols of the link and transport layers for many existing and emerging systems in the field of wireless communications.