http://bura.brunel.ac.uk/handle/2438/210 2013-06-18T06:32:27Z 2013-06-18T06:32:27Z Wu, Zujian http://bura.brunel.ac.uk/handle/2438/7413 2013-05-03T09:26:03Z 2012-01-01T00:00:00Z

Title: A generic approach to behaviour-driven biochemical model construction Authors: Wu, Zujian Abstract: Modelling of biochemical systems has received considerable attention over the last decade from bioengineering, biochemistry, computer science, and mathematics. This thesis investigates the applications of computational techniques to computational systems biology, for the construction of biochemical models in terms of topology and kinetic rates. Due to the complexity of biochemical systems, it is natural to construct models representing the biochemical systems incrementally in a piecewise manner. Syntax and semantics of two patterns are defined for the instantiation of components which are extendable, reusable and fundamental building blocks for models composition. We propose and implement a set of genetic operators and composition rules to tackle issues of piecewise composing models from scratch. Quantitative Petri nets are evolved by the genetic operators, and evolutionary process of modelling are guided by the composition rules. Metaheuristic algorithms are widely applied in BioModel Engineering to support intelligent and heuristic analysis of biochemical systems in terms of structure and kinetic rates. We illustrate parameters of biochemical models based on Biochemical Systems Theory, and then the topology and kinetic rates of the models are manipulated by employing evolution strategy and simulated annealing respectively. A new hybrid modelling framework is proposed and implemented for the models construction. Two heuristic algorithms are performed on two embedded layers in the hybrid framework: an outer layer for topology mutation and an inner layer for rates optimization. Moreover, variants of the hybrid piecewise modelling framework are investigated. Regarding flexibility of these variants, various combinations of evolutionary operators, evaluation criteria and design principles can be taken into account. We examine performance of five sets of the variants on specific aspects of modelling. The comparison of variants is not to explicitly show that one variant clearly outperforms the others, but it provides an indication of considering important features for various aspects of the modelling. Because of the very heavy computational demands, the process of modelling is paralleled by employing a grid environment, GridGain. Application of the GridGain and heuristic algorithms to analyze biological processes can support modelling of biochemical systems in a computational manner, which can also benefit mathematical modelling in computer science and bioengineering. We apply our proposed modelling framework to model biochemical systems in a hybrid piecewise manner. Modelling variants of the framework are comparatively studied on specific aims of modelling. Simulation results show that our modelling framework can compose synthetic models exhibiting similar species behaviour, generate models with alternative topologies and obtain general knowledge about key modelling features. Description: This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.

2012-01-01T00:00:00Z Zhuang, Y Wang, Z Yu, H Wang, W Lauria, S http://bura.brunel.ac.uk/handle/2438/7367 2013-06-07T11:14:25Z 2013-01-01T00:00:00Z

Title: A robust extended H∞ filtering approach to multi-robot cooperative localization in dynamic indoor environments Authors: Zhuang, Y; Wang, Z; Yu, H; Wang, W; Lauria, S Abstract: Multi-robot cooperative localization serves as an essential task for a team of mobile robots to work within an unknown environment. Based on the real-time laser scanning data interaction, a robust approach is proposed to obtain optimal multi-robot relative observations using the Metric-based Iterative Closest Point (MbICP) algorithm, which makes it possible to utilize the surrounding environment information directly instead of placing a localization-mark on the robots. To meet the demand of dealing with the inherent non-linearities existing in the multi-robot kinematic models and the relative observations, a robust extended H∞ filtering (REHF) approach is developed for the multi-robot cooperative localization system, which could handle non-Gaussian process and measurement noises with respect to robot navigation in unknown dynamic scenes. Compared with the conventional multi-robot localization system using extended Kalman filtering (EKF) approach, the proposed filtering algorithm is capable of providing superior performance in a dynamic indoor environment with outlier disturbances. Both numerical experiments and experiments conducted for the Pioneer3-DX robots show that the proposed localization scheme is effective in improving both the accuracy and reliability of the performance within a complex environment. Description: This is the post-print version of the Article. The official published version can be accessed from the link below - Copyright @ 2013 Elsevier.

2013-01-01T00:00:00Z Clarke, M Jones, R Fursse, J http://bura.brunel.ac.uk/handle/2438/7366 2013-06-03T14:37:27Z 2012-01-01T00:00:00Z

Title: Towards an integrated and interoperable platform for telehealth and telecare Authors: Clarke, M; Jones, R; Fursse, J Abstract: We present experience of implementing and evaluating a platform purpose designed to integrate interoperable telehealth and telecare. We chose the IEEE 11073 standards for all devices and used ZigBee wireless to support many devices concurrently and exploit its mesh networking to extend range around the entire house. We designed the home gateway to be unobtrusive; in project Hydra we used the smart meter and in other projects (Reaction, inCasa) we have developed a purpose designed plugtop ZigBee to GPRS gateway. All use common protocols and are interoperable. Technically the projects have been a success, and we have already implemented a wide range of devices on the common platform (BP, weight, SpO2, glucose, PIR, medication monitor, bed/chair sensor). Immediate feedback from participants has confirmed our goal of simplicity and convenience of use (and thus encourage adherence); and it is interesting that in discussion they then focus on the data rather than the technology. Our current goal is to exploit the potential for combination of physiological and environmental data to determine if change of habits can be detected and how this correlates with change in health. We are using this functionality to manage the frail elderly within project inCasa and we propose to present preliminary findings. Description: Copyright @ 2012 International Journal of Integrated Care (IJIC). This work is licensed under a (http://creativecommons.org/licenses/by/3.0) Creative Commons Attribution 3.0 Unported License.

2012-01-01T00:00:00Z Ahmi, Aidi http://bura.brunel.ac.uk/handle/2438/7357 2013-04-19T14:53:21Z 2012-01-01T00:00:00Z

Title: Adoption of generalised audit software (GAS) by external auditors in the UK Authors: Ahmi, Aidi Abstract: This research is motivated by the interest in understanding the usage of the Generalised Audit Software (GAS) by external auditors within public accounting firms. GAS is a tool used by auditors to automate various audit tasks. It helps auditors to analyse accounting data electronically where it is quite impossible to do so manually. GAS is claimed to be the most influential Computer Assisted Audit Tools and Technique (CAATTs) that can facilitate the audit objective. However, research has found that there is little evidence that auditors have extensively adopted GAS. Even greater benefits have been promoted since the existence of GAS, but auditors do not really seem to be interested in this tool. Most previous studies have focused on either internal auditors, large accounting firms, other countries or merely adopters of GAS. However, there is little evidence that the study of GAS has been conducted on external auditors, especially in small and medium sized accounting firms in the United Kingdom (UK). This study helps to fill this gap by exploring the use of GAS among them, and covers both adopters and non-adopters of GAS. Through an online survey using both close and open-ended questions, this issue has been investigated among registered statutory auditors. The primary aim of this study is to explore the current usage of GAS and to understand the factors that influence the use of GAS as well as the perceptions and expectations of using GAS. The views are gathered from both auditors who are already implementing GAS and those who are not using GAS. A framework was developed to identify a range of relevant factors which are important when considering the application of GAS. Responses from 205 statutory auditors across the UK were then mapped against the framework. Of the 14 variables used to test the factors that influence the use of GAS, only six of them are found to be significant from logistic regression analysis. These are firm size, experience of auditors in computerised auditing, organisational influence, client factor, audit engagement allocation and perceived usefulness. The findings show that the utilisations of GAS is unusually low among audit firms in the UK. Almost 73% of external auditors make no use of GAS, due to the limited perceived benefit of using GAS for auditing small clients. While some respondents recognised the advantages of GAS, they were put off by what they believed to be high implementation costs; the significant learning curve and adoption process; and lack of ease of use. Some auditors expressed their awareness of GAS, but most of them showed a preference for using traditional auditing methods instead. A few problems have also been identified in causing the limitation of GAS usage. This study contributes to the literature on suggestions to improve the use of GAS that can be used by small and medium sized public accounting firm, which is lacking in existing research related to this group. In sum, this study has deepened current understanding of the GAS usage among small and medium sized audit firms in the UK, and has provided useful insights for audit professionals, software developers, vendors, standards setters, academicians and researchers. This study has also opened up the possibilities for further study on GAS or related areas either in the UK or other places in the world. Description: This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.

2012-01-01T00:00:00Z