State-space model identification of a wireless THz network

We model the large scale fading of wireless THz communications links deployed in a metropolitan area taking into account reception through direct line of sight, ground or wall reflection and diffraction. The movement of the receiver in the three dimensions is modelled by an autonomous dynamic linear system in state-space whereas the geometric relations involved in the attenuation and multi-path propagation of the electric field are described by a static non-linear mapping. A subspace algorithm in conjunction with polynomial regression is used to identify a Wiener model from time-domain measurements of the field intensity.

Wiener-System subspace identification for mobile wireless mm-wave networks

We discuss the feasibility of wireless terahertz communications links deployed in a metropolitan area and model the large-scale fading of such channels. The model takes into account reception through direct line of sight, ground and wall reflection, as well as diffraction around a corner. The movement of the receiver is modeled by an autonomous dynamic linear system in state space, whereas the geometric relations involved in the attenuation and multipath propagation of the electric field are described by a static nonlinear mapping. A subspace algorithm in conjunction with polynomial regression is used to identify a single-output Wiener model from time-domain measurements of the field intensity when the receiver motion is simulated using a constant angular speed and an exponentially decaying radius. The identification procedure is validated by using the model to perform q-step ahead predictions. The sensitivity of the algorithm to small-scale fading, detector noise, and atmospheric changes are discussed. The performance of the algorithm is tested in the diffraction zone assuming a range of emitter frequencies (2, 38, 60, 100, 140, and 400 GHz). Extensions of the simulation results to situations where a more complicated trajectory describes the motion of the receiver are also implemented, providing information on the performance of the algorithm under a worst case scenario. Finally, a sensitivity analysis to model parameters for the identified Wiener system is proposed.

MIMO Wiener model identification for large scale fading of wireless mobile communications links

The large scale fading of wireless mobile communications links is modelled assuming the mobile receiver motion is described by a dynamic linear system in state-space. The geometric relations involved in the attenuation and multi-path propagation of the electric field are described by a static non-linear mapping. A Wiener system subspace identification algorithm in conjunction with polynomial regression is used to identify a model from time-domain estimates of the field intensity assuming a multitude of emitters and an antenna array at the receiver end.

Sparse polynomial approximation in positive order Sobolev spaces with bounded mixed derivatives and applications to elliptic problems with random loading

In the present paper we study the approximation of functions with bounded mixed derivatives by sparse tensor product polynomials in positive order tensor product Sobolev spaces. We introduce a new sparse polynomial approximation operator which exhibits optimal convergence properties in L2 and tensorized View the MathML source simultaneously on a standard k-dimensional cube. In the special case k=2 the suggested approximation operator is also optimal in L2 and tensorized H1 (without essential boundary conditions). This allows to construct an optimal sparse p-version FEM with sparse piecewise continuous polynomial splines, reducing the number of unknowns from O(p2), needed for the full tensor product computation, to View the MathML source, required for the suggested sparse technique, preserving the same optimal convergence rate in terms of p. We apply this result to an elliptic differential equation and an elliptic integral equation with random loading and compute the covariances of the solutions with View the MathML source unknowns. Several numerical examples support the theoretical estimates.

What is the new medicines use review ‘patient survey’ attempting to capture in the context of existing patient satisfaction with pharmacy questionnaires and a new conceptual framework?

The community pharmacy service medicines use review (MUR) was introduced in 2005 ‘to improve patient knowledge, concordance and use of medicines’ through a private patient–pharmacist consultation. The MUR presents a fundamental change in community pharmacy service provision. While traditionally pharmacists are dispensers of medicines and providers of medicines advice, and patients as recipients, the MUR considers pharmacists providing consultation-type activities and patients as active participants. The MUR facilitates a two-way discussion about medicines use. Traditional patient–pharmacist behaviours transform into a new set of behaviours involving the booking of appointments, consultation processes and form completion, and the physical environment of the patient–pharmacist interaction moves from the traditional setting of the dispensary and medicines counter to a private consultation room. Thus, the new service challenges traditional identities and behaviours of the patient and the pharmacist as well as the environment in which the interaction takes place. In 2008, the UK government concluded there is at present too much emphasis on the quantity of MURs rather than on their quality.[1] A number of plans to remedy the perceived imbalance included a suggestion to reward ‘health outcomes’ achieved, with calls for a more focussed and scientific approach to the evaluation of pharmacy services using outcomes research. Specifically, the UK government set out the main principal research areas for the evaluation of pharmacy services to include ‘patient and public perceptions and satisfaction’as well as ‘impact on care and outcomes’. A limited number of ‘patient satisfaction with pharmacy services’ type questionnaires are available, of varying quality, measuring dimensions relating to pharmacists’ technical competence, behavioural impressions and general satisfaction. For example, an often cited paper by Larson[2] uses two factors to measure satisfaction, namely ‘friendly explanation’ and ‘managing therapy’; the factors are highly interrelated and the questions somewhat awkwardly phrased, but more importantly, we believe the questionnaire excludes some specific domains unique to the MUR. By conducting patient interviews with recent MUR recipients, we have been working to identify relevant concepts and develop a conceptual framework to inform item development for a Patient Reported Outcome Measure questionnaire bespoke to the MUR. We note with interest the recent launch of a multidisciplinary audit template by the Royal Pharmaceutical Society of Great Britain (RPSGB) in an attempt to review the effectiveness of MURs and improve their quality.[3] This template includes an MUR ‘patient survey’. We will discuss this ‘patient survey’ in light of our work and existing patient satisfaction with pharmacy questionnaires, outlining a new conceptual framework as a basis for measuring patient satisfaction with the MUR. Ethical approval for the study was obtained from the NHS Surrey Research Ethics Committee on 2 June 2008. References 1. Department of Health (2008). Pharmacy in England: Building on Strengths – Delivering the Future. London: HMSO. www. official-documents.gov.uk/document/cm73/7341/7341.pdf (accessed 29 September 2009). 2. Larson LN et al. Patient satisfaction with pharmaceutical care: update of a validated instrument. JAmPharmAssoc 2002; 42: 44–50. 3. Royal Pharmaceutical Society of Great Britain (2009). Pharmacy Medicines Use Review – Patient Audit. London: RPSGB. http:// qi4pd.org.uk/index.php/Medicines-Use-Review-Patient-Audit. html (accessed 29 September 2009).

Young people with intellectual disabilities attending mainstream and segregated schooling: perceived stigma, social comparison and future aspirations

Mainstream schooling is a key policy in the promotion of social inclusion of young people with learning disabilities. Yet there is limited evidence about the school experience of young people about to leave mainstream as compared with segregated education, and how it impacts on their relative view of self and future aspirations. Sixty young people with mild to moderate intellectual disabilities in their final year of secondary school participated in this study. Twenty-eight individuals came from mainstream schools and 32 attended segregated school. They completed a series of self-report measures on perceptions of stigma, social comparison to a more disabled and non-disabled peer and the likelihood involved in attaining their future goals. The majority of participants from both groups reported experiencing stigmatized treatment in the local area where they lived. The mainstream group reported significant additional stigma at school. In terms of social comparisons, both groups compared themselves positively with a more disabled peer and with a non-disabled peer. While the mainstream pupils had more ambitious work-related aspirations, both groups felt it equally likely that they would attain their future goals. Although the participants from segregated schools came from significantly more deprived areas and had lower scores on tests of cognitive functioning, neither of these factors appeared to have an impact on their experience of stigma, social comparisons or future aspirations. Irrespective of schooling environment, the young people appeared to be able to cope with the threats to their identities and retained a sense of optimism about their future. Nevertheless, negative treatment reported by the children was a serious source of concern and there is a need for schools to promote the emotional well-being of pupils with intellectual disabilities.

Neural networks for identification of nonlinear systems under random piecewise polynomial disturbances

The problem of identification of a nonlinear dynamic system is considered. A two-layer neural network is used for the solution of the problem. Systems disturbed with unmeasurable noise are considered, although it is known that the disturbance is a random piecewise polynomial process. Absorption polynomials and nonquadratic loss functions are used to reduce the effect of this disturbance on the estimates of the optimal memory of the neural-network model.

Identification of linear systems in the presence of piecewise polynomial disturbances

The paper proposes a method of performing system identification of a linear system in the presence of bounded disturbances. The disturbances may be piecewise parabolic or periodic functions. The method is demonstrated effectively on two example systems with a range of disturbances.

Neurofuzzy network model construction using Bézier-Bernstein polynomial functions

Neurofuzzy modelling systems combine fuzzy logic with quantitative artificial neural networks via a concept of fuzzification by using a fuzzy membership function usually based on B-splines and algebraic operators for inference, etc. The paper introduces a neurofuzzy model construction algorithm using Bezier-Bernstein polynomial functions as basis functions. The new network maintains most of the properties of the B-spline expansion based neurofuzzy system, such as the non-negativity of the basis functions, and unity of support but with the additional advantages of structural parsimony and Delaunay input space partitioning, avoiding the inherent computational problems of lattice networks. This new modelling network is based on the idea that an input vector can be mapped into barycentric co-ordinates with respect to a set of predetermined knots as vertices of a polygon (a set of tiled Delaunay triangles) over the input space. The network is expressed as the Bezier-Bernstein polynomial function of barycentric co-ordinates of the input vector. An inverse de Casteljau procedure using backpropagation is developed to obtain the input vector's barycentric co-ordinates that form the basis functions. Extension of the Bezier-Bernstein neurofuzzy algorithm to n-dimensional inputs is discussed followed by numerical examples to demonstrate the effectiveness of this new data based modelling approach.

Generalized neurofuzzy network modeling algorithms using Bezier-Bernstein polynomial functions and additive decomposition

This paper introduces a new neurofuzzy model construction algorithm for nonlinear dynamic systems based upon basis functions that are Bezier-Bernstein polynomial functions. This paper is generalized in that it copes with n-dimensional inputs by utilising an additive decomposition construction to overcome the curse of dimensionality associated with high n. This new construction algorithm also introduces univariate Bezier-Bernstein polynomial functions for the completeness of the generalized procedure. Like the B-spline expansion based neurofuzzy systems, Bezier-Bernstein polynomial function based neurofuzzy networks hold desirable properties such as nonnegativity of the basis functions, unity of support, and interpretability of basis function as fuzzy membership functions, moreover with the additional advantages of structural parsimony and Delaunay input space partition, essentially overcoming the curse of dimensionality associated with conventional fuzzy and RBF networks. This new modeling network is based on additive decomposition approach together with two separate basis function formation approaches for both univariate and bivariate Bezier-Bernstein polynomial functions used in model construction. The overall network weights are then learnt using conventional least squares methods. Numerical examples are included to demonstrate the effectiveness of this new data based modeling approach.

Out of the ivory tower: the impact of wider social contact on the values, religious beliefs and identities of Chinese postgraduate students in the UK

This article explores the impact of wider social contact on the experience of Chinese postgraduate students of adaptation to life in the UK. Focus group and individual interviews were conducted with a group of 11 Chinese students on an MA programme at a university in southern England and individual interviews with three representatives of a local volunteer group (LVG) offering support to the Chinese students. Although it was perceived that the students’ support needs were not adequately met by the University, the additional support offered outside the University was unanimously valued and considered as enriching their cultural and linguistic experiences and meeting their expectations. However, frequent social contact with the LVG, whose members were mostly Christians, also had an impact on their values, religious beliefs and identities. In a discussion framed within the sociological perspective of proselytization or religious conversion and the broad framework of international education and globalization, the different responses to this contact are described in terms of believers, doubters, empathisers and commentators. Implications are considered for universities, people involved in providing social support for international students, and sponsors of international students.

Contested and contesting identities: minority languages vs. the teaching of 'world' languages within the global cultural economy

This paper juxtaposes postmodernist discourses on language, identity and cultural power with historical forms of language inequalities grounded in the nation-state. The discussion is presented in three sections. The first section focuses on the mixed legacies of language-state relations within the pluralist nation-state, colonial and postcolonial language policies. The second section examines the concept of linguistic minority rights beyond the nation-state. This incorporates discussion of transmigration, the breaking up of previous power blocs in Eastern Europe and the role of language in the articulation of emergent 'ethnic' nationalisms. The third section examines the concept of multilingualism within the interactive cultural landscape defined by 'informationalism'. Discussing the collective impact of these variables on the shaping of new cultural, economic and political inequalities, the paper highlights the tensions in which the concept of linguistic minority rights exists in the world today.