A study of simulated annealing and a revised cascade algorithm for image reconstruction

We describe an image reconstruction problem and the computational difficulties arising in determining the maximum a posteriori (MAP) estimate. Two algorithms for tackling the problem, iterated conditional modes (ICM) and simulated annealing, are usually applied pixel by pixel. The performance of this strategy can be poor, particularly for heavily degraded images, and as a potential improvement Jubb and Jennison (1991) suggest the cascade algorithm in which ICM is initially applied to coarser images formed by blocking squares of pixels. In this paper we attempt to resolve certain criticisms of cascade and present a version of the algorithm extended in definition and implementation. As an illustration we apply our new method to a synthetic aperture radar (SAR) image. We also carry out a study of simulated annealing, with and without cascade, applied to a more tractable minimization problem from which we gain insight into the properties of cascade algorithms.     

Protected areas in the periphery: Conservation and controversy in northern Scotland

Controversies arising from the notification of large areas of land as Sites of Special Scientific Interest in northern Scotland are reviewed against the background of surveys of land occupiers' experiences on the one hand, and of trends in conservation thinking in the wider world on the other. Most of the protected area is of low capability for productive land use, and there is little evidence of adverse trends in labour and employment on SSSIs compared with similar, non-SSSI land. Site designation has in practice impeded land management in the cases of relatively few land occupiers, but rather more have negative attitudes towards it. It is concluded that some elements of the ‘scientific colonialism’ model of protected areas can be detected.     

Solving the Labour Problem Among Professional Workers in the UK Public Sector: Organisation Change and Performance Management

This paper draws together evidence from across the UK public services to present an analysis of public sector organisational change that has been observed and experienced since the 1980s. The argument is that the pattern of persistent change, packaged as a myriad of reform measures, has been centrally concerned with solving the labour problem—low worker productivity and managers not being able to manage—in what are labour intensive services. The now familiar managerial discourse of empowerment and high commitment working practices is highlighted and express linkages are drawn between such themes and the day-to-day practices of performance and human resource management, seen here to be key levers in solving the same labour problem through a reduction in the quality of working lives of many public service workers.     

Promoting psychosocial well-being in unaccompanied asylum seeking young people in the United Kingdom

Unaccompanied minors looking for asylum in industrialized nations come with a host of psychosocial needs associated with separation and settlement. They are also resourceful, and willing to make the best of themselves in their new environments. This paper reviews literature concerning vulnerability and resilience that has emerged from refugee related studies, and those from social work with children looked after by local authorities. In combining these two areas of enquiry, the paper tests the messages they contain in reference to the work of a young asylum seekers project run in the United Kingdom. It confirms the view that unaccompanied minors are children first and foremost, exhibiting understandable vulnerabilities associated with separation and trauma, as well as being carriers of capacities that can help them to recover and settle after arrival. In this paper, it is proposed that promoting psychosocial well‐being for unaccompanied minors involves entering the young people's inner and outer worlds with therapeutic care, to aid the processes of self‐recovery. It also involves finding ways to regenerate a lost sense of belonging and of being in charge of their lives. Examples from the project's work with the young people are used to illustrate the complexity of helping them find a sense of home within their new territories.     

Familial spinal shape

It has been proposed that there is a familial relationship in the shape of the spine. This paper describes a pilot study investigating familial shape in the sagittal plane (side view), using three data sets of normal Leeds schoolchildren. The study is exploratory in nature, because only small samples were available. Data acquisition was by means of the Quantec system, which obtains surface shape measurements and extracts a line representing the spinal curve. The coordinates of the spine line in the sagittal plane are then used to investigate familial correlations of spinal shape. The spine lines first undergo some preprocessing, including Procrustes rotations to remove location, rotation and size effects. Smoothed principal component analysis of the curves provides suitable shape variables, and familial correlations between curves are then investigated. The covariates of sex and height are also investigated in the analysis. It does appear that there could be some evidence for familial correlations in sagittal spinal shape, although a further large-scale study is required. Finally, a discussion of the approach and other alternatives is considered.     

Difficulties in the use of auxiliary variables in Markov chain Monte Carlo methods

Markov chain Monte Carlo (MCMC) methods are now widely used in a diverse range of application areas to tackle previously intractable problems. Difficult questions remain, however, in designing MCMC samplers for problems exhibiting severe multimodality where standard methods may exhibit prohibitively slow movement around the state space. Auxiliary variable methods, sometimes together with multigrid ideas, have been proposed as one possible way forward. Initial disappointing experiments have led to data-driven modifications of the methods. In this paper, these suggestions are investigated for lattice data such as is found in imaging and some spatial applications. The results suggest that adapting the auxiliary variables to the specific application is beneficial. However the form of adaptation needed and the extent of the resulting benefits are not always clear-cut.     

Do Schooling and Work Empower Women in Developing Countries? Gender and Domestic Decisions in Sri Lanka

Our work challenges and points out the limitations of the theoretical presumptions underlying the relationship between empowerment, education, and employment that have been emphasized in both the exiting literature and the current rhetoric to empower women in developing countries. We use survey, life history, and focus group data to empirically examine the relationship between schooling, paid work, and power in domestic decision making for young, married women in Sri Lanka. We argue that the relationship between education, work, and women's control of household decisions is conditioned by the larger social context, and as such, it is likely to reflect the extent to which the division of labor and access to information and economic resources are the bases of domestic power in the society under consideration. Our results make a strong case for the need to move away from broad-based conceptualizations of women's empowerment to a consideration of the specific arenas and dimensions along which women can have power. In focusing on the domestic arena alone, we find that there are important differences in both the nature and determinants of the financial as opposed to the social and organizational dimension of power in Sri Lankan households. Women who control one of these aspects of family decisions do not necessarily control the other, and while education and employment play an important role in determining women's input in financial decisions, they are largely immaterial in determining household decisions related to social and organizational matters. Our results also demonstrate the importance of going beyong simplistic and limited measures of schooling and work to consider more fundamental structural factors involving family, social, and economic organization.     

Child care in an age of family differences

The importance of understanding America's day care needs has become a major issue in society today. Understanding these needs involves more than simply providing spaces for care. The uniqueness of each family's situation requires research into differing family expectations. This paper provides some insight into differences between single mothers and fathers in their utilization of child care.