System oriented neural networks - Problem formulation, methodology and application

A novel methodology is proposed for the development of neural network models for complex engineering systems exhibiting nonlinearity. This method performs neural network modeling by first establishing some fundamental nonlinear functions from a priori engineering knowledge, which are then constructed and coded into appropriate chromosome representations. Given a suitable fitness function, using evolutionary approaches such as genetic algorithms, a population of chromosomes evolves for a certain number of generations to finally produce a neural network model best fitting the system data. The objective is to improve the transparency of the neural networks, i.e. to produce physically meaningful

Child abuse as a complex and wicked problem: Reflecting on policy developments in the United Kingdom in working with children and families with multiple problems

In spite of significant public concern, professional efforts and financial expenditure, there has been a perceived lack of progress in reducing the incidence of child abuse, and in improving the outcomes for children in both the short and longer term. In this article the authors reflect on recent policy developments in the United Kingdom relating to children and families experiencing multiple adversities, and argue that the current conceptualisation of child abuse is flawed. In adopting a rational technical approach to the management of child abuse, there is a tendency to focus on shorter term outcomes for the child, such as immediate safety, that primarily reflect the outputs of the child protection system. However, by viewing child abuse as a wicked problem, that is complex and less amenable to being solved, then child welfare professionals can be supported to focus on achieving longer term outcomes for children that are more likely to meet their needs. The authors argue for an earlier identification of and intervention with children who are experiencing multiple adversity, such as those living with parents misusing substances and exposed to intimate partner violence.

Generation of a transient short pulse X-ray laser using a traveling-wave sub-ps pump pulse

This paper summarises die main results obtained during the two experimental campaigns on TCE X-ray lasers that we have carried out since the last Kyoto X-ray laser Conference in 1998. A two-color (2 omega /1 omega) pumping configuration was tested and led to the observation of a strong lasing line at 16 nm, identified to a 4f-4d transition in Ni-like Ag. A strong x 300-400 enhancement of the 13.9 nm Ni-like 4d-4p lasing emission was obtained when a traveling wave short pulse pumping was applied. Finally the temporal history of the 13.9 nm laser pulse was measured with a high-resolution Streak camera, A very short 2 ps X-ray laser pulse was directly demonstrated for the first time.

A Hybrid Evolutionary Approach to the Nurse Rostering Problem

Nurse rostering is a difficult search problem with many constraints. In the literature, a number of approaches have been investigated including penalty function methods to tackle these constraints within genetic algorithm frameworks. In this paper, we investigate an extension of a previously proposed stochastic ranking method, which has demonstrated superior performance to other constraint handling techniques when tested against a set of constrained optimisation benchmark problems. An initial experiment on nurse rostering problems demonstrates that the stochastic ranking method is better in finding feasible solutions but fails to obtain good results with regard to the objective function. To improve the performance of the algorithm, we hybridise it with a recently proposed simulated annealing hyper-heuristic within a local search and genetic algorithm framework. The hybrid algorithm shows significant improvement over both the genetic algorithm with stochastic ranking and the simulated annealing hyper-heuristic alone. The hybrid algorithm also considerably outperforms the methods in the literature which have the previously best known results.

British drugs policy: Problematizing the distinction between legal and illegal drugs and the definition of the ‘drugs problem’.

This article draws upon an extensive literature review of the social and medical sciences, official documents and various websites to critically re-evaluate the basis of British drugs policy. The article problematizes the rationale for criminalizing certain substances and questions the distinctions created between legal and illegal drugs; in so doing, the article argues that the definition of the `drugs problem' is the real problem. It shows that the debate on illegal drugs is filled less with factual truths and more with misinformation which creates public fear and provides a questionable basis for public policy. The article questions current thinking regarding the drugs/crime relationship and concludes by exploring some implications for policy and practice.