Content-prioritised video coding for British Sign Language communication.

Video communication of British Sign Language (BSL) is important for remote interpersonal communication and for the equal provision of services for deaf people. However, the use of video telephony and video conferencing applications for BSL communication is limited by inadequate video quality. BSL is a highly structured, linguistically complete, natural language system that expresses vocabulary and grammar visually and spatially using a complex combination of facial expressions (such as eyebrow movements, eye blinks and mouth/lip shapes), hand gestures, body movements and finger-spelling that change in space and time. Accurate natural BSL communication places specific demands on visual media applications which must compress video image data for efficient transmission. Current video compression schemes apply methods to reduce statistical redundancy and perceptual irrelevance in video image data based on a general model of Human Visual System (HVS) sensitivities. This thesis presents novel video image coding methods developed to achieve the conflicting requirements for high image quality and efficient coding. Novel methods of prioritising visually important video image content for optimised video coding are developed to exploit the HVS spatial and temporal response mechanisms of BSL users (determined by Eye Movement Tracking) and the characteristics of BSL video image content. The methods implement an accurate model of HVS foveation, applied in the spatial and temporal domains, at the pre-processing stage of a current standard-based system (H.264). Comparison of the performance of the developed and standard coding systems, using methods of video quality evaluation developed for this thesis, demonstrates improved perceived quality at low bit rates. BSL users, broadcasters and service providers benefit from the perception of high quality video over a range of available transmission bandwidths. The research community benefits from a new approach to video coding optimisation and better understanding of the communication needs of deaf people

Visual perception of content-prioritised sign language video quality.

Video communication systems currently provide poor quality and performance for deaf people using sign language, particularly at low bit rates. Our previous work, involving eye movement tracking experiments and analysis of visual attention mechanisms for sign language, demonstrated a consistent characteristic response which could be exploited to enable optimisation of video coding systems performance by prioritising content for deaf users. This paper describes an experiment designed to test the perceived quality of selectively prioritised video for sign language communication. A series of selectively degraded video clips was shown to individual deaf viewers. Participants subjectively rated the quality of the modified video on a Degradation Category Rating (DCR) scale adapted for sign language users. The results demonstrate the potential to develop content-prioritised coding schemes, based on viewing behaviour, which can reduce bandwidth requirements and provide best quality for the needs of the user. We propose selective quantisation to reduce compression in visually important regions of video images, which require spatial detail for small slow motion detection, and increased compression of regions regarded in peripheral vision where large rapid movements occur in sign language communication

TUNING OPTIMIZATION SOFTWARE PARAMETERS FOR MIXED INTEGER PROGRAMMING PROBLEMS

The tuning of optimization software is of key interest to researchers solving mixed integer programming (MIP) problems. The efficiency of the optimization software can be greatly impacted by the solver’s parameter settings and the structure of the MIP. A designed experiment approach is used to fit a statistical model that would suggest settings of the parameters that provided the largest reduction in the primal integral metric. Tuning exemplars of six and 59 factors (parameters) of optimization software, experimentation takes place on three classes of MIPs: survivable fixed telecommunication network design, a formulation of the support vector machine with the ramp loss and L1-norm regularization, and node packing for coding theory graphs. This research presents and demonstrates a framework for tuning a portfolio of MIP instances to not only obtain good parameter settings used for future instances of the same class of MIPs, but to also gain insights into which parameters and interactions of parameters are significant for that class of MIPs. The framework is used for benchmarking of solvers with tuned parameters on a portfolio of instances. A group screening method provides a way to reduce the number of factors in a design and reduces the time it takes to perform the tuning process. Portfolio benchmarking provides performance information of optimization solvers on a class with instances of a similar structure

Quantum Cryptography

Quantum cryptography could well be the first application of quantum mechanics at the individual quanta level. The very fast progress in both theory and experiments over the recent years are reviewed, with emphasis on open questions and technological issues.Comment: 55 pages, 32 figures; to appear in Reviews of Modern Physic

Regional Integration and Poverty: A case study of Bolivia

This paper investigates the impacts of regional integration processes on poverty in Bolivia. It first demonstrates that regional integration has stimulated a diversion of trade away from traditional US and EU markets towards countries of MERCOSUR and the Andean Community. At the same time, the composition of exports has changed from predominantly minerals towards slightly more elaborated goods, such as vegetable fats, food and beverages. The paper presents econometric analyses of the impact of imports, exports and FDI (by sector, and trade block) on individual labor incomes and household poverty status. The results show that higher exports generally tend to benefit the workers who work in the exporting sectors. However, this result only holds for export sectors that exploit some natural resource rents (mining, hydrocarbons, modern agriculture), and not for those which rely purely on low wages in order to be competitive (most manufacturing sectors). Imports typically have a negative effect on worker salaries, except the imports of capital goods, which do not compete with local production. This implies that the change towards more regional trade of goods with a smaller natural resource rent component is unlikely to contribute to a reduction in poverty. For exports and FDI to be helpful for reducing poverty, they would have to focus on sectors, which are labor intensive and at the same time exploit some natural resource rents. Sectors that might fulfill these criteria are modern agriculture and tourism.Regional integration, poverty, Bolivia

Teleconsultation perspective for cardiovascular patients in Saudi Arabia

This thesis was submitted for the degree of Doctor of Philosophy and awarded by Brunel University.This research of teleconsultation services aims to improve the quality of diagnosis and treatment for rural cardiovascular patients through utilizing distant medical expertise. Equitable access to expert healthcare as well as improved medical management for these patients can assist in modifying cardiovascular disease (CVD) risk and reduce morbidity and mortality in Saudi Arabia. The objectives were to design and develop a new care pathway for cardiovascular disease patients by utilizing teleconsultation technology, investigate factors and issues that might act as barriers to its adoption, and then evaluate the impact of this model on the stakeholders. A small scale pilot project was used to determine the issues of technology, processes and human resources required to deliver an effective service with the context of the research setting. Four primary healthcare centres, two regional hospitals, fifteen patients and sixty other participant stakeholders were included in this study. An approach using (PCP) patient care pathways was used to introduce the teleconsultation technology and integrate it within the healthcare delivery system. Compared to the traditional PCP, the modified PCP utilising teleconsultation technology improved the quality of healthcare through: Improved access to medical care and quality of diagnosis by obtaining the expertise of a distant specialist. More efficient medical evaluation and management. Enhanced role of primary healthcare centres and participating hospitals by providing all levels of health services for patients. Evidence-based referral (reduced waiting time, reduced burden on outpatient clinics). The telconsultation adoption barriers included: Inadequacy of finance Limited infrastructure Legal and regularity difficulties. Organization issues. Literacy on technology. This study recommends the following for telemedicine implementation in the country: Promote perception and readiness for ICT services with the healthcare community. Enhance structural readiness including appropriate infrastructure and adequate funding, human resources and equipment. Proactive policies to encourage growth of the telecommunication sector and to address concerns regarding privacy and security