Adaptive sequential Monte Carlo by means of mixture of experts

Appropriately designing the proposal kernel of particle filters is an issue of significant importance, since a bad choice may lead to deterioration of the particle sample and, consequently, waste of computational power. In this paper we introduce a novel algorithm adaptively approximating the so-called optimal proposal kernel by a mixture of integrated curved exponential distributions with logistic weights. This family of distributions, referred to as mixtures of experts, is broad enough to be used in the presence of multi-modality or strongly skewed distributions. The mixtures are fitted, via online-EM methods, to the optimal kernel through minimisation of the Kullback-Leibler divergence between the auxiliary target and instrumental distributions of the particle filter. At each iteration of the particle filter, the algorithm is required to solve only a single optimisation problem for the whole particle sample, yielding an algorithm with only linear complexity. In addition, we illustrate in a simulation study how the method can be successfully applied to optimal filtering in nonlinear state-space models.     

Stories from the circle: Leadership lessons learned from aboriginal leaders

While much has been written about leadership, very little research has examined North American Aboriginal leadership. Drawing upon a qualitative methodology, our findings suggest several differences in how Aboriginal leaders view leadership; compared to non-Aboriginals or mainstream approaches to leadership. We found that Aboriginals view leadership as a spiritual endeavor that is holistic and egalitarian in nature. Aboriginal leaders use a more indirect style of communication that frequently invokes traditional imagery, story-telling and animal-based metaphors. Aboriginal leaders also draw from the Medicine Wheel as a guide. In conclusion, we discuss several challenges shared by Aboriginal leaders including the tall poppy syndrome and walking in two worlds and accordingly, offer managerial implications of our findings.     

Frantz Fanon,poet: pleasure of the text,power of the text

ABSTRACT

Frantz Fanon’s writing represents a productive embrace of the political and the poetic. His ideas have had such a long afterlife, they live on in us, I submit, precisely because the language of their articulation, image-filled and rhythmic, is compelling. This article examines three elements of Fanonian poetics in Black Skin, White Masks: the use of metaphor and, in “By Way of Conclusion,” an ambiguous/multiple “I” as persona, and, finally, what Brent Edwards has called “anaphoric poetics,” the repetition of the same word or words at the beginning of successive phrases.     

Inventory management maximization based on sales forecast: case study

The major purpose of this paper is to present a concept for reliable planning of the sales of small firms, where the large number of product variants complicates the implementation of this kind of system considerably. First, a methodology is presented to set up sales forecasting so that it can be integrated into the inventory management process. This inventory management software interprets forecasting information and provides users with a decision support system to minimize stocks in stores while at the same time avoiding missed sales. It is best applied in company types requiring high precision inventories, notably those in the textile industry; a large range of patterns are produced with many small variations (colors, size, customizations, etc.) and these products have a limited lifetime. Inventory management is difficult due to the multitude of products to account for and the necessity to sell them quickly. The methodology is intended for inventory management at the end of the supply chain. In store, the number of references, their similarities and the necessity to minimize unsold stock greatly complicates the reordering and restocking process. These types of companies do not easily lend themselves to classic techniques of sales forecasting and require specialized methods to estimate their needs precisely.     

Administrer un monde incertain : les nouvelles bureaucraties techniques. Le cas des agences sanitaires en France

The creation of health agencies in France has stimulated public interventions in the managing of risks and emergencies. Health agencies are not mere technical organizations set up in response to a particular health crisis. They are political forms stemming from deeper social and political changes in public administration, scientific expertise and medicine. Part of a threefold trend toward opening administrative, scientific and medical doors, they have emerged out of the transformation of the public administration under the impact of theories about: new public management, the transparency of scientific expertise, and the development of public health. These processes are paradoxical however. They tend to favor the growth of new technical bureaucracies, whence questions about the latter's political responsibility. While agencies were supposed to reduce bureaucracy, they have broadened its borders and reinforced its structures. They constitute an intermediary space, where appear tensions between them and their supervisors. This arangement does singularly transform the balance between administrative and political powers. — Special issue: New patterns of institutions.     

LARGE AND MODERATE DEVIATIONS PRINCIPLES FOR KERNEL ESTIMATION OF A MULTIVARIATE DENSITY AND ITS PARTIAL DERIVATIVES

This paper studies the large deviations behaviour of the kernel estimator of a probability density f, by considering the case when the kernel takes negative values. It establishes large and moderate deviations principles for the kernel estimators of the partial derivatives of f. The estimators of the derivatives exhibit a quadratic behaviour for both the large and the moderate deviations scales, whereas for the density estimator there is a classical gap between the large deviations and the moderate deviations asymptotics.     

Slicing Up the Pie: Allocation of Central Government Funding of Care of Older People

The allocation of central government funds is a critical element in the equitable provision of local authority‐commissioned and ‐provided services. A variety of approaches to allocating funding for social services for older people have been used over the years, most recently founded on ‘needs‐based’ formulae. In 2004, the Department of Health for England commissioned research to help inform the improvement and updating of the formula. The results of individual‐level analyses were compared with the results obtained from analyses of small area (ward‐level) data on service users. Both analyses were affected by problems of data availability, particularly the individual‐level analysis, and the Department of Health and the (then) Office of the Deputy Prime Minister decided that the formula calculations should be based on the results of the small area analysis. However, despite the differences in approach, both methods produced very similar results. The correlation between the predicted relative needs weights for local authorities from the two models was 0.982. The article discusses the strengths and weaknesses of each approach and developments that could allow a normative approach that would incorporate future policy objectives into formulae that, to date, have inevitably been based on historical data and service patterns.     

Mental Illness as a Barrier to Marriage Among Unmarried Mothers

This study explores how mental illness shapes transitions to marriage among unwed mothers using augmented data from the Fragile Families and Child Wellbeing study (N= 2,351). We estimate proportional hazard models to assess the effects of mental illness on the likelihood of marriage over a 5‐year period following a nonmarital birth. Diagnosed mental illness was obtained from the survey respondents’ prenatal medical records. We find that mothers with mental illness are about two thirds as likely as mothers without mental illness to marry, even after controlling for demographic characteristics, and that human capital, relationship quality, partner selection, and substance abuse appear to explain only a small proportion of the effect of mental illness on marriage.     

Entre « passion » et incertitude : la socialisation au métier de footballeur professionnel

On the basis of a socioethnographic survey conducted in a professional soccer training center in France, the means of occupational socialization are analyzed in this demanding, captivating institution. Light is shed on how trainees appropriate this professional world and its requirements. As they enter this social universe, they encounter a key tension. On the one hand, training calls for a heavy investment that trainers and trainees experience as a “passion” and understand as being separate from the world of “ordinary” work. On the other hand, it is also a major source of uncertainty as to trainees’ prospects, given its intense selectivity and the few outlets in the labor market. It requires of trainees a strong commitment in time, body and spirit with prospects so uncertain that the course of training is seldom free from periods of soul-searching.     

An ecological systems approach to understanding social support in foster family resilience

Families who care for children in the foster care system often experience challenges related to the system, accessing services and supports, and managing relationships. Despite these challenges, many families thrive because of unique attributes and strengths that contribute to experiences of resilience. Using an ecological framework, this study examined social support among resilient foster families to better understand how foster caregivers experienced positive reciprocal transactions across systems. As part of a larger study, in‐depth narrative interviews were conducted to examine the process of resilience for families who foster. Findings revealed that families accessed and benefited from social support on micro‐level, meso‐level and macro‐level. Understanding how families cultivated social support across multiple levels offers implications for practice and policy when considering how best to retain and support families who care for vulnerable children.