On the symmetries of Siklos spacetimes

We consider the large class of Siklos spacetimes and investigate their relevant symmetries (homothetic and affine vector fields, Ricci, curvature, Weyl and matter collineations). We prove some general results and obtain complete classifications for homogeneous Siklos spacetimes

Semi-active control for independently rotating wheelset in railway vehicles with MR dampers

This thesis presents details of an investigation of a controller for MR damper in the implementation of semi-active control, for primary suspensions of the independently rotating railway vehicles. This research focuses on using MR damper and it addresses on three main aspects when designing semi-active control systems for this application.One aspect is magnetorheological dampers categorised as a controllable fluid damper which can reversibly change from a flowing viscose fluid to semi-solid viscose fluid. The second aspect is the controllable yield strength can change in a millisecond by inducing an electric or magnetic field. Third aspect is MR damper is cheaper than actuators which are usually use in full active controllerThis research is a combination of a lookup table based on the inverse MR damper model to control the current input (to the MR damper) from required force and relative velocity of the device. The MR damper produces the desired force as precisely as possible. However, it is not possible to have precise knowledge of MR parameters and it is also difficult to account for the hysteresis present in MR dampers in the lookup table. Therefore, an additional local PI feedback controller is also used to improve the robustness for the MR control.As the main result, this study provides a comparison between semi-active controller with the use of MR damper and a full active controller system. The results show semi-active controller with the use of MR damper performed as good as full active controller. However semi-active control systems with MR dampers offer an overall efficiency and robustness when compared to the full active control system. Also, this system delivers comparable performance with the benefit of increased reliability and lower cost.In order to assess the developed system comprehensively, a two–axle vehicle model and a full bogie vehicle model are both evaluated individually in the study.The performance and robustness assessments of the developed semi-active controller with the full active control system are evaluated with the use of both two–axle vehicle model and the full bogie vehicle model with different operational track features such as curved track and straight track with lateral irregularities with various travel speeds.This study designed and developed a semi-active control systems with use of MR damper in primary suspension for independent rotation wheelsets in railway vehicles. Computer simulation results verified the suggested semi-active control is able to provide required stability and guidance control for independently- rotating wheelsets. Also, the result performed as well as full active control with the advantage of utilizing a lower cost device for semi-active control rather than an expensive actuator for full active control

Application of distributed lighting control architecture in dementia-friendly smart homes

Dementia is a growing problem in societies with aging populations, not only for patients, but also for family members and for the society in terms of the associated costs of providing health care. Helping patients to maintain a degree of independence in their home environment while ensuring their safeties is considered as a positive step forward for addressing individual needs of dementia patients. A common symptom for dementia patients including those with Alzheimer's Disease and Related Dementia (ADRD) is sleep disturbance, patients being awake at night and asleep during the day. One of the problems with night time sleep disturbance in dementia patients is the possible accidental falls of patients in the dark environment. An issue associated with un-hourly sleeping behavior in these patients is the lighting condition of their surroundings. Clinical studies indicate that appropriate level of lightning can help to restore the rest-activity cycles of ADRD patients. This study tackles this problem by generating machine learning solutions for controlling the lighting conditions of multiple rooms in the house in different hours based on patterns of behaviors generated for the patient. Several neural network oriented classification methods are investigated and their feasibilities are assessed with a collection of synthetic data capturing two conditions of balanced and unbalanced inter-class samples. The classifiers are utilized within two centric and distributed lighting control architectures. The results indicate the feasibility of the distributed architecture in achieving a high level of classification performance resulting in adequate control over lighting conditions of the house in various time periods

SPARC 2017 retrospect & prospects : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2017 SPARC conference. This year we not only celebrate the work of our PGRs but also the 50th anniversary of Salford as a University, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 130 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to exploit this great opportunity to engage with researchers working in different subject areas to your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers

SPARC 2018 Internationalisation and collaboration : Salford postgraduate annual research conference book of abstracts

Welcome to the Book of Abstracts for the 2018 SPARC conference. This year we not only celebrate the work of our PGRs but also the launch of our Doctoral School, which makes this year’s conference extra special. Once again we have received a tremendous contribution from our postgraduate research community; with over 100 presenters, the conference truly showcases a vibrant PGR community at Salford. These abstracts provide a taster of the research strengths of their works, and provide delegates with a reference point for networking and initiating critical debate. With such wide-ranging topics being showcased, we encourage you to take up this great opportunity to engage with researchers working in different subject areas from your own. To meet global challenges, high impact research inevitably requires interdisciplinary collaboration. This is recognised by all major research funders. Therefore engaging with the work of others and forging collaborations across subject areas is an essential skill for the next generation of researchers

Homogeneous geodesics and natural reductivity of homogeneous Gödel-type spacetimes

We prove that all geodesics of homogeneous Gödel-type metrics are homogeneous. This result makes natural to ask whether these spaces are naturally reductive, and a positive answer is provided for all of them through the study of their homogeneous Lorentzian structures