Back propagation neural networks and multiple regressions in the case of heteroskedasticity

This paper compares the performance between regression analysis and a clustering based neural network approach when the data deviates from the homoscedasticity assumption of regression. Heteroskedasticity is a problem that arises in linear regression due to the unequal error variances. One of the methods to deal heteroskedasticity in classical regression theory is weighted least-square regression (WLS). In order to deal the problem of heteroskedasticity, backpropagation neural network is applied. In this context, an algorithm is proposed which is based on robust estimates of location and dispersion matrix that helps in preserving the error assumption of the linear regression. Analysis is carried out with appropriate designs using simulated data and the results are presented.     

Hallmarks of the Political in Community Organizing: An Arendtian Perspective

VOLUNTAS: International Journal of Voluntary and Nonprofit Organizations - Drawing upon Hannah Arendt’s adherence to existential phenomenology, the article advances a political understanding...     

State Immigration Policies: The Role of State Compacts and Interest Groups on Immigration Legislation

US states are active in enacting immigration policies, which vary widely and have substantial impact on the lives of immigrants. Our understanding of what produces these divergent state laws remains limited. Qualitative research demonstrates the importance of a 2010 immigration compact, supported by a powerful religious organization, in shaping immigration policies in Utah, and the Utah Compact was held up as a model for other states. But is the experience of Utah applicable across other states? We test the effects of compacts and interest groups on immigration policy adoption across all 50 states between 2005 and 2013. Our findings suggest that compacts are actually associated with more restrictive immigration policy. Although states with compacts are more likely to pass inclusive immigration laws, these are counterbalanced by higher numbers of exclusive laws. Both religious and non‐religious interests groups are associated with policy, but they do not explain the effects of compacts.     

The resources of ageing? Middle‐aged gay men's accounts of Manchester's gay voluntary organizations

Middle‐aged men's experiences of gay voluntary organizations (GVOs) are neglected in research. To address this knowledge gap, this article extends Bourdieusian theorizing beyond that deployed by Hakim (2010) and Green (2008) concerning ‘erotic capital’ to demonstrate how norms in GVOs can facilitate or frustrate mobilization of ‘ageing capital’ by middle‐aged gay men living in Manchester (UK), which has implications for comparable cities within and beyond a UK context. Based on interviews with 22 men aged 39–55, this article demonstrates how ‘ageing capital’ can facilitate challenge to gay ageism but also how such ageism can frustrate and even overwhelm men's capacities to deploy ageing capital in generic GVOs, thus reinforcing intergenerational conflict and expression of ageism towards younger gay men. In doing so, this article contributes to knowledge about the reproduction of the relations of ageism in a particular field of gay existence.     

A Tiered Framework for Risk‐Relevant Characterization and Ranking of Chemical Exposures: Applications to the National Children's Study (NCS)

A challenge for large‐scale environmental health investigations such as the National Children's Study (NCS), is characterizing exposures to multiple, co‐occurring chemical agents with varying spatiotemporal concentrations and consequences modulated by biochemical, physiological, behavioral, socioeconomic, and environmental factors. Such investigations can benefit from systematic retrieval, analysis, and integration of diverse extant information on both contaminant patterns and exposure‐relevant factors. This requires development, evaluation, and deployment of informatics methods that support flexible access and analysis of multiattribute data across multiple spatiotemporal scales. A new “Tiered Exposure Ranking” (TiER) framework, developed to support various aspects of risk‐relevant exposure characterization, is described here, with examples demonstrating its application to the NCS. TiER utilizes advances in informatics computational methods, extant database content and availability, and integrative environmental/exposure/biological modeling to support both “discovery‐driven” and “hypothesis‐driven” analyses. “Tier 1” applications focus on “exposomic” pattern recognition for extracting information from multidimensional data sets, whereas second and higher tier applications utilize mechanistic models to develop risk‐relevant exposure metrics for populations and individuals. In this article, “tier 1” applications of TiER explore identification of potentially causative associations among risk factors, for prioritizing further studies, by considering publicly available demographic/socioeconomic, behavioral, and environmental data in relation to two health endpoints (preterm birth and low birth weight). A “tier 2” application develops estimates of pollutant mixture inhalation exposure indices for NCS counties, formulated to support risk characterization for these endpoints. Applications of TiER demonstrate the feasibility of developing risk‐relevant exposure characterizations for pollutants using extant environmental and demographic/socioeconomic data.     

Racial battle fatigue and activist burnout in racial justice activists of color at predominately White colleges and universities

Activist burnout scholarship has inadequately considered challenges marginalized-identity activists, such as racial justice activists of color, experience in the course of their activism – challenges from which privileged identity activists, such as white racial justice activists, are protected. This article attempts to address this gap through a phenomenological study examining activist burnout in racial justice activists of color whose primary sites of activism are predominantly white colleges and universities in the United States at which they work. In order to stretch activist burnout theory to differentiate unique marginalized-identity activists’ burnout causes from general causes that do not consider specific activist identities, the lens of racial battle fatigue is employed. Findings show that, although participants shared many causes of burnout that are consistent with general non-identity-specific causes described in existing literature, racial battle fatigue hastened their burnout while their activist commitments elevated their battle fatigue.     

Marketing as an Investment in Shareholder Value

We present resource‐based and capability‐based arguments of marketing investment intensity to offer a strategic view of marketing as an investment in shareholder value. We find that marketing investment intensity has a U‐shaped quadratic effect on shareholder value creation (Tobin's q) that calls for marketing investment to be protected and increased, not surrendered. We show how marketing investments interact with investments in R&D, human capital and operations to reveal how strategic co‐investments can alter the shareholder value of marketing. Finally, we show how competitive intensity and failings in the firm's investment productivity (its ability to convert investment expenditure into sales) point to malaise in the firm's own strategic architecture as a fault for perceived poor returns from marketing investments. Our findings suggest that marketing investment should not be scapegoated when its contributions to shareholder value are not as expected. When invested in strategically and in combination with other investments, marketing can unlock exciting improvements in shareholder value.     

Reflecting on the Past: A Content Analysis of Family Therapy Research from 2000‐2015

In this content analysis, researchers examine articles published from 2000 to 2015 in three family therapy journals, yielding a total of 948 empirical articles. The purpose is to provide an overview of the research being published, assess who is publishing, and investigate the current state of clinical effectiveness research in marriage and family therapy (MFT). Most first authors were affiliated with MFT programs and primarily included diversity and couples in their research. There was a significant increase of research on clinical process—though the number of clinical outcome studies held steady. There were no significant changes with regard to research funding. Implications support the use of innovative research methods to provide evidence of clinical effectiveness.     

Major Accidents (Gray Swans) Likelihood Modeling Using Accident Precursors and Approximate Reasoning

Compared to the remarkable progress in risk analysis of normal accidents, the risk analysis of major accidents has not been so well‐established, partly due to the complexity of such accidents and partly due to low probabilities involved. The issue of low probabilities normally arises from the scarcity of major accidents’ relevant data since such accidents are few and far between. In this work, knowing that major accidents are frequently preceded by accident precursors, a novel precursor‐based methodology has been developed for likelihood modeling of major accidents in critical infrastructures based on a unique combination of accident precursor data, information theory, and approximate reasoning. For this purpose, we have introduced an innovative application of information analysis to identify the most informative near accident of a major accident. The observed data of the near accident were then used to establish predictive scenarios to foresee the occurrence of the major accident. We verified the methodology using offshore blowouts in the Gulf of Mexico, and then demonstrated its application to dam breaches in the United Sates.