Local linear regression with adaptive orthogonal fitting for the wind power application

Short-term forecasting of wind generation requires a model of the function for the conversion of meteorological variables (mainly wind speed) to power production. Such a power curve is nonlinear and bounded, in addition to being nonstationary. Local linear regression is an appealing nonparametric approach for power curve estimation, for which the model coefficients can be tracked with recursive Least Squares (LS) methods. This may lead to an inaccurate estimate of the true power curve, owing to the assumption that a noise component is present on the response variable axis only. Therefore, this assumption is relaxed here, by describing a local linear regression with orthogonal fit. Local linear coefficients are defined as those which minimize a weighted Total Least Squares (TLS) criterion. An adaptive estimation method is introduced in order to accommodate nonstationarity. This has the additional benefit of lowering the computational costs of updating local coefficients every time new observations become available. The estimation method is based on tracking the left-most eigenvector of the augmented covariance matrix. A robustification of the estimation method is also proposed. Simulations on semi-artificial datasets (for which the true power curve is available) underline the properties of the proposed regression and related estimation methods. An important result is the significantly higher ability of local polynomial regression with orthogonal fit to accurately approximate the target regression, even though it may hardly be visible when calculating error criteria against corrupted data.     

"My spirit in my heart": identity experiences and challenges among American Indian two-spirit women

Many Native women embrace the term two-spirit to capture their sexuality and gender expression. By analyzing the narratives of five two-spirit women who are Native activists, we explored contemporary understandings of the concept and what it means for Native communities. The incorporation of the identity within indigenous worldviews, its manifestation in terms of (be)coming out, and the triple stressors of heterosexism, racism, and sexism emerged as key themes.     

Law Struggles and Hegemonic Processes in Neoliberal India: Gramscian Reflections on Land Acquisition Legislation

Abstract

This article explores how, in the context of an unfolding process of neoliberalisation in India, new terrains of resistance are crystallising for subaltern groups seeking to contest the marginalising consequences of this process. We focus particularly on the emergence of India's ‘new rights agenda’ through a study of the making of the Right to Fair Compensation and Transparency in Land Acquisition, Rehabilitation and Resettlement Bill, 2013. Conceiving of the emergence of the ‘new rights agenda’ as a hegemonic process, we decipher how law-making is a complex and contradictory practice seeking to negotiate a compromise equilibrium between, on the one hand, subaltern groups vulnerable to marginalisation and capable of mobilisation; and, on the other, dominant groups whose economic interests are linked to the exploitation of the spaces of accumulation recently pried open by market-oriented reforms. The negotiation of this equilibrium, we suggest, is ultimately intended to facilitate India's process of neoliberalisation.     

Chinks in Gender?

This comment argues that differences between clinical and normal populations, between clinical data and sociological data, and differences in social class and cultural settings should be taken into account in order to understand the varying psychological dynamics behind self representations. Research from the Nordic countries indicates that young women's relationships with their mothers and fathers are becoming more similar. The daughters appreciate their mothers' ability to combine independent lives of their own with care for children and family, and fathers are to a higher degree than before perceived as warm and caring figures. This may imply that the gender-differentiated psychological roles of the mother and the father in the heterosexual nuclear family are becoming less distinct. If chinks undermine not only the merged attachment but also gender as such, this question arises: What ways and to what extent are the new psychological dispositions Susie Orbach describes actually gendered?     

Transnational diaspora entrepreneurship in emerging markets: Bridging institutional divides

Transnational diasporan entrepreneurs are migrants and their descendants who establish entrepreneurial activities that span the national business environments of their countries of origin and countries of residence. We explore how business incubators contribute to the economic development of emerging markets by organizing their programs to bridge the institutional divides that transnational diaspora entrepreneurs face when establishing their multi-territorial ventures in these markets. Drawing on qualitative fieldwork conducted in the Netherlands during 2007, we present the case study of IntEnt, an incubator providing services exclusively to transnational diasporan entrepreneurs. We apply Bergek and Norrman's (2008) assessment framework to this case, examining IntEnt's goals, model (selection, business support, and mediation activities), and outcomes. Employing Eisenhardt's case-based theory development approach (1989), we then leverage case findings to generate theory about the institutional challenges faced by transnational diaspora entrepreneurs and the role that incubators can play in helping these entrepreneurs overcome these challenges.     

Child labour or school attendance? Evidence from Zambia

In this paper we investigate what affects school attendance and child labour in an LDC, using data for Zambia. Since the data comes from a household survey with information on all household members it allows us to take account of unobserved household effects by introducing household-specific effects in a logit model. The empirical analysis suggests that both economic and sociological variables are important determinants for the choice between school attendance and child labour. In particular, we find some support for the hypothesis that poverty forces households to keep their children away from school. JEL classification: J24, I21, O15 Received May 20, 1996/Accepted January 2, 1997     

Time for renewal

During hard economic times, college health professionals must urge their supervisors and administrators to help them maintain or find new funding so that they can attend regional and national conferences of the American College Health Association. In this viewpoint, a nurse from a small college shares the various sources of funding she discovered to enable her to attend regional and national conference of the American College Health Association that saved her from burnout and also motivated her to strive for changes through setting goals.     

Leading well is a matter of resources: Leader vigour and peer support augments the relationship between transformational leadership and burnout

ABSTRACT

Although studies suggest that transformational leaders play an important role in employee health and well-being, the relationship between transformational leadership and employee burnout remains unclear. One reason may be that moderators may play an important role. Building on conservation of resources theory, we examined if leaders’ perceptions of internal and external resources in terms of vigour and peer support augmented the relationship between transformational leadership and employee burnout in a sample of municipality workers and their leaders in Sweden (N?=?217). Multilevel analyses over two time points revealed that both vigour and peer support enhance this relationship, such that when leaders experience high levels of vigour or peer support, the negative relationship between transformational leadership behaviours and employee burnout was strengthened. Our findings suggest that both personal and contextual resources may help leaders to better engage in transformational leadership, which is important in order to protect employees from burning out.     

Evaluation of Methods for Assessing the Oral Bioavailability of Inorganic Mercury in Soil

The risks associated with environmental exposures to inorganic mercury are typically assessed based on toxicity studies conducted with the soluble salt, mercuric chloride (HgCl₂). Evidence indicates, however, that inorganic mercury is present in soil as a variety of compounds and that oral absorption of inorganic mercury decreases with a decrease in the solubility of the mercury compound being studied. Thus, while HgCl₂ is approximately 15–20% bioavailable, the bioavailability of cinnabar (HgS) may be 30- to 60-fold less. The solubility and, hence, bioavailability of inorganic mercury in soil is expected to be substantially less than that of HgCl₂ due to the presence of less soluble compounds and their interactions with soil constituents. Quantification of this difference in bioavailability is important in assessing potential risks associated with exposure to mercury-containing soil. A review of available studies supports the expectation that mercury bioavailability in soils will be reduced. This paper reviews methods for assessing soil metal absorption with consideration of the characteristics of the oral absorption of elemental and inorganic mercury that should be evaluated in designing additional studies. Because of the very slow elimination of mercury in some species, it is recommended that a repeated-dose study be conducted. Such a study would yield an estimate of relative bioavailability based on a comparison of tissue mercury concentrations in animals ingesting soil with those of animals receiving HgCl₂. The dose, age, gender, and species of animal selected are not expected to affect relative bioavailability estimates; however, it is recommended that studies be conducted in two animal species. Rats should be used because they have been used in many studies of mercury absorption and toxicity. A species of large animals such as monkeys, swine, or dogs should also be used to provide confirmation in a species with greater similarities to humans in gastrointestinal physiology and anatomy. Other critical factors in designing these studies, such as selection and characterization of soil samples, are also addressed.     

An optimization interpretation of integration and back-fitting estimators for separable nonparametric models

We provide an optimization interpretation of both back-fitting and integration estimators for additive nonparametric regression. We find that the integration estimator is a projection with respect to a product measure. We also provide further understanding of the back-fitting method.