Using tabu search and genetic algorithms in mathematics research

This paper discusses an ongoing project which uses computational heuristic search techniques such as tabu search and genetic algorithms as a tool for mathematics research. We discuss three ways in which such search techniques can be useful for mathematicians: in nding counterexamples to conjectures, in enumerating examples, and in nding sequences of transformations between two objects which are conjectured to be related. These problem-types are discussed using examples from topology

Thinking about Attention in Games: Backward and Forward Induction

Behavioral economics improves economic analysis by using psychological regularity to suggest limits on rationality and self-interest (e.g. Camerer and Loewenstein 2003). Expressing these regularities in formal terms permits productive theorizing, suggests new experiments, can contribute to psychology, and can be used to shape economic policies which make normal people better off

Is it Time for Computational Creativity to Grow Up and Start being Irresponsible?

A recent definition of computational creativity has em- phasised that computational creativity systems should “take on certain responsibilities” for generating creative behaviour. This paper examines the notion of responsibilities in that definition, and looks at a number of aspects of the creative act and its context that might play a role in that responsibility, with an emphasis on artistic and musical creativity. This problematises the seemingly simple distinction between systems that have responsibilities for creative activity and those which support or provide tools for creativity. The paper con- cludes with a discussion of an alternative approach to the subject, which argues that the responsibility for creative action is typically diffused through a complex human/computer system, and that a “systems thinking” approach to locating computational creativity might ask better questions than one that tries to pin creative responsibility to a particular agent

A secular increase in continental crust nitrogen during the Precambrian

Recent work indicates the presence of substantial geologic nitrogen reservoirs in the mantle and continental crust. Importantly, this geologic nitrogen has exchanged between the atmosphere and the solid Earth over time. Changes in atmospheric nitrogen (i.e. atmospheric mass) have direct effects on climate and biological productivity. It is difficult to constrain, however, the evolution of the major nitrogen reservoirs through time. Here we show a secular increase in continental crust nitrogen through Earth history recorded in glacial tills (2.9 Ga to modern), which act as a proxy for average upper continental crust composition. Archean and earliest Palaeoproterozoic tills contain 66 $\pm$ 100 ppm nitrogen, whereas Neoproterozoic and Phanerozoic tills contain 290 $\pm$ 165 ppm nitrogen, whilst the isotopic composition has remained constant at ~4\permil. Nitrogen has accumulated in the continental crust through time, likely sequestered from the atmosphere via biological fixation. Our findings support dynamic, non-steady state behaviour of nitrogen through time, and are consistent with net transfer of atmospheric N to geologic reservoirs over time.Comment: 14 pages, 2 figures, 2 tables, supplemental informatio

Towards a methodology for rigorous development of generic requirements patterns

We present work in progress on a methodology for the engineering, validation and verification of generic requirements using domain engineering and formal methods. The need to develop a generic requirement set for subsequent system instantiation is complicated by the addition of the high levels of verification demanded by safety-critical domains such as avionics. We consider the failure detection and management function for engine control systems as an application domain where product line engineering is useful. The methodology produces a generic requirement set in our, UML based, formal notation, UML-B. The formal verification both of the generic requirement set, and of a particular application, is achieved via translation to the formal specification language, B, using our U2B and ProB tools

An Artificial Synaptic Plasticity Mechanism for Classical Conditioning with Neural Networks

We present an artificial synaptic plasticity (ASP) mechanism that allows artificial systems to make associations between environmental stimuli and learn new skills at runtime. ASP builds on the classical neural network for simulating associative learning, which is induced through a conditioning-like procedure. Experiments in a simulated mobile robot demonstrate that ASP has successfully generated conditioned responses. The robot has learned during environmental exploration to use sensors added after training, improving its object-avoidance capabilities

An appetite for learning : increasing employee demand for skills development

Raising the demand for skills amongst individuals in the workforce is critical if the UK is to meet its 2020 Ambition. This edition of Praxis highlights a number of policy interventions that the evidence suggests can work, and proposes a policy framework for describing and understanding these. The paper aims to stimulate wider debate about the policy interventions most likely to address the barriers to learning faced by the UK workforce. To this end the UK Commission welcomes readers' responses to the following questions, prompted by this paper