Most Popular Books by IAN ROBERTS

Ideal for classroom or independent study, this revision workbook is the smart choice for studying on the foundation tier for Edexcel GCSE science.

Droving has been hugely important in shaping farming practice across Northumberland for 1,000 years or more. The necessity of transporting sheep and cattle has changed the landscape, developed the roads and buildings, and at one time, animals would be herded from as far a field as Scotland and Ireland. Today the scene is very different but the legacy of the drovers can still be seen and enjoyed all over the region. Local archaeologists Ian Roberts, Alan Rushworth, and Richard Calrton have been determined to preserve this history on behalf of the Northumberland National Park Authority. Following the development of droving in Northumberland from prehistoric times, through Middle Ages, the eighteenth century and right up to date, they offer the definitive history of this significant activity.

Radical empathy manifests itself when you recognize that you do not have to go to happy hour or drink coffee with someone in order to understand their point of view and work with them. In fact, some of the most productive leaders focus less on social goals and understand that there will be variances in lived experiences but we must still be willing to work with people and help to leverage their unique perspectives in order to achieve better outcomes in schools.

Channel power and rate optimization objectives are examined in nonlinear long-haul optical communication networks. Problems of maximizing the minimum channel margin and maximizing fiber capacity are found to have convex forms. The Kerr nonlinear inter- and intra-channel nonlinear interference is initially modelled via the Gaussian noise nonlinearity model. Valuable performance benefits are obtained in inhomogeneous scenarios including mesh networks. The inhomogeneity introduced by the additional nonlinear impairment of stimulated Raman scattering makes the optimization objective non-convex, but also provides inherent inhomogeneity that supports performance benefits from power optimization. The discrete-rate optimization objective is formulated for maximizing the real-world capacity of optical communication systems with discrete code rates. Efficient heuristic methods are proposed that make use of a sequence of calls to solve the minimum-margin channel power optimization problem. Lastly, the channel power optimization problem is generalized with a model that applies beyond the dispersion-uncompensated domain of the Gaussian noise model. A first-order perturbation-based approach is used for the nonlinear interference modelling.