Minimum neighbour and extended Kalman filter estimator: a practical distributed channel assignment scheme for dense wireless local area networks

Dense deployments of wireless local area networks (WLANs) are becoming a norm in many cities around the world. However, increased interference and traffic demands can severely limit the aggregate throughput achievable unless an effective channel assignment scheme is used. In this work, a simple and effective distributed channel assignment (DCA) scheme is proposed. It is shown that in order to maximise throughput, each access point (AP) simply chooses the channel with the minimum number of active neighbour nodes (i.e. nodes associated with neighbouring APs that have packets to send). However, application of such a scheme to practice depends critically on its ability to estimate the number of neighbour nodes in each channel, for which no practical estimator has been proposed before. In view of this, an extended Kalman filter (EKF) estimator and an estimate of the number of nodes by AP are proposed. These not only provide fast and accurate estimates but can also exploit channel switching information of neighbouring APs. Extensive packet level simulation results show that the proposed minimum neighbour and EKF estimator (MINEK) scheme is highly scalable and can provide significant throughput improvement over other channel assignment schemes.

Untangling rhetoric and reality in the CSR debate – the role of corporate social responsibility in effective business strategy

While there is a strong moral case for corporate social responsibility (CSR), the business case for CSR is certainly not irrefutable. A better understanding of how to integrate CSR into business strategy is needed but with ever increasing momentum towards sustainability as a business driver, it is often difficult to untangle the rhetoric from reality in the CSR debate. Through an analysis of eight case studies of leading firms from throughout the construction supply chain who claim to engage in CSR, we explore how consulting and contracting firms in the construction and engineering industries integrate CSR into their business strategy. Findings point to an inherent caution of moving beyond compliance and to a risk-averse culture which adopts very narrow definitions of success. We conclude that until this culture changes or the industry is forced by clients or regulation to change, the idea of CSR will continue to mean achieving economic measures of success, with ecological goals a second regulated priority and social goals a distant third.

An implicit pole-assignment self-tuning regulator

A new self-tuning implicit pole-assignment algorithm is presented which, through the use of a pole compression factor and different RLS model and control structures, overcomes stability and convergence problems encountered in previously available algorithms. Computational requirements of the technique are much reduced when compared to explicit pole-assignment schemes, whereas the inherent robustness of the strategy is retained.

Pathways to inflated responsibility beliefs in adolescent obsessive-compulsive disorder: a preliminary investigation

Background: An inflated sense of responsibility is characteristic of obsessive-compulsive disorder (OCD). No previous studies have investigated its origins. Five potential pathways to inflated responsibility beliefs have been proposed; these are tested in this study. Method: A novel measure, the Origins Questionnaire for Adolescents (OQA), was developed to assess experiences on these five pathways. Reliability of the OQA was investigated. The experiences on the five pathways to inflated responsibility beliefs of sixteen adolescents with a history of OCD were compared to sixteen adolescents with no history of OCD. Parents also reported on adolescents’ experiences on the five pathways. Results: Inter-rater reliability was high. The internal consistency of the subscales were only partly satisfactory. The groups differed on one pathway; the clinical group reported a higher sense of responsibility for significant incidents with a negative outcome prior to onset of OCD. Conclusions: An inflated sense of responsibility, in combination with the occurrence of specific incidents, might act as a vulnerability factor for development of OCD. Future research should consider how to measure the subtle effects of experiences of responsibility over the course of development.

Optimal control of a class of discrete–continuous non-linear systems — decomposition and hierarchical structure

A technique is derived for solving a non-linear optimal control problem by iterating on a sequence of simplified problems in linear quadratic form. The technique is designed to achieve the correct solution of the original non-linear optimal control problem in spite of these simplifications. A mixed approach with a discrete performance index and continuous state variable system description is used as the basis of the design, and it is shown how the global problem can be decomposed into local sub-system problems and a co-ordinator within a hierarchical framework. An analysis of the optimality and convergence properties of the algorithm is presented and the effectiveness of the technique is demonstrated using a simulation example with a non-separable performance index.

Stakeholder-defined corporate responsibility for a pre-credit-crunch financial service company: lessons for how good reputations are won and lost

This paper presents a study that identifies a stakeholder-defined concept of Corporate Responsibility (CR) in the context of a UK financial service organisation in the immediate pre-credit crunch era. From qualitative analysis of interviews and focus groups with employees and customers, we identify, in a wide-ranging stakeholder-defined concept of CR, six themes that together imply two necessary conditions for a firm to be regarded as responsible— both corporate actions and character must be consonant with CR. This provides both empirical support for a notable, recent theoretical contribution by Godfrey (in Acad Manag Rev 30:777–798, 2005) and novel lessons for reputation management practice.