A distribution-dependent Mumford-Shah model for unsupervised hyperspectral image segmentation

Hyperspectral images provide a rich representation of the underlying spectrum for each pixel, allowing for a pixel-wise classification/segmentation into different classes. As the acquisition of labeled training data is very time-consuming, unsupervised methods become crucial in hyperspectral image analysis. The spectral variability and noise in hyperspectral data make this task very challenging and define special requirements for such methods. Here, we present a novel unsupervised hyperspectral segmentation framework. It starts with a denoising and dimensionality reduction step by the well-established Minimum Noise Fraction (MNF) transform. Then, the Mumford-Shah (MS) segmentation functional is applied to segment the data. We equipped the MS functional with a novel robust distribution-dependent indicator function designed to handle the characteristic challenges of hyperspectral data. To optimize our objective function with respect to the parameters for which no closed form solution is available, we propose an efficient fixed point iteration scheme. Numerical experiments on four public benchmark datasets show that our method produces competitive results, which outperform two state-of-the-art methods substantially on three of these datasets

'In the minds of men': Representations of war and military interventions

This chapter reviews (primarily social psychological) research on representations of war and military intervention. This research has approached the object of investigation in various ways, focusing to a lesser or greater extent on contextual and historical processes, and assigning differential weight to the social meanings attached to war and military intervention. Furthermore, there are differences in terms of the research’s conceptualization of individual positions toward war and military intervention and the role of group memberships and intergroup relations. The chapter tries to bring together research findings from these different traditions by drawing implications for strategies to change representations of war and military interventions. We end by offering questions for future research

How Racist Violence Becomes a Virtue: An Application of Discourse Analysis

This discourse analytic study examines how violence can be constructed as an honourable course of action, using the example of a leaflet circulated in the loyalist Donegall Pass area of Belfast urging the removal of the minority Chinese population. Starting from the assumptions that racism is an ideological practice that naturalises social categories and devalues members of some of them so that their subjugation and exclusion is legitimised (Miles and Brown 2003; Billig 2002), and that violence is a human activity imbued with meaning through discourse, we applied guidelines set out by Parker (1992) to consider language as a social practice that achieves specific discursive effects by constructing its objects in a particular way. Two interrelated discourses were identified: a community-focused discourse construed the Chinese immigrants as morally and culturally bereft and negated their worth, while a martial discourse focused on defending the locality against foreign invasion. An examination of themes in loyalist culture revealed ways in which the text reconstructed resonant fears, and we argue that the way the in-group constructs its character defines the racist construction of the other

Differentiating between belief-indicative and status-indicative groups improves predictions of intergroup attitudes

Ingroup bias is often treated as the default outcome of intergroup comparisons. We argue that the mechanisms of impression formation depend on what information people infer from groups. We differentiate between belief-indicative groups that are more informative of beliefs and affect attitudes through ingroup bias and status-indicative groups that are more informative of status and affect attitudes through a preference for higher status. In a cross-cultural factorial experiment (Ntotal = 1,281), we demonstrate that when information about targets' multiple group memberships is available, belief-indicative groups affect attitudes via ingroup bias, whereas status-indicative groups-via preference for higher status. These effects were moderated by social-structural context. In two follow-up studies (Ntotal = 451), we develop and validate a measure of belief- and status-indicativeness (BISI) of groups. BISI showed expected correlations with related constructs of entitativity and essentialism. Belief-indicativeness of groups was a better predictor of ingroup bias than entitativity and essentialism

Multiple categorization and intergroup bias: examining the generalizability of three theories of intergroup relations

Research on intergroup bias usually focuses on a single dimension of social categorization. In real life, however, people are aware of others’ multiple group memberships and use this information to form attitudes about them. The present research tests the predictive power of identification, perceived conflict, and perceived symbolic threat in explaining the strength of intergroup bias on various dimensions of social categorization in multiple categorization settings. We conduct a factorial survey experiment, manipulating 9 dimensions of social categorization in diverse samples from 4 countries (n = 12,810 observations, 1,281 participants representing 103 social groups). The dimensions studied are age, gender, ethnicity, religion, place of residence, education, occupation, income, and 1 country-specific dimension. This approach allows exploring the generalizability of established determinants of bias across dimensions of categorization, contexts, and target groups. Identification and symbolic threat showed good generalizability across countries and categorization dimensions, but their effects varied as a function of participant and target groups’ status. Identification predicted stronger bias mainly when the participant belonged to a higher status and the target belonged to a lower status group. Symbolic threat predicted stronger bias mainly when the target was a minority group member. Conflict predicted bias only in few cases, and not only the strength but also the direction of the effects varied across countries, dimensions, and target and participant groups. These findings help to clarify the limits of generalizability of established determinants of intergroup bias and highlight the need for new explanations of social–cognitive processes among minority group members

Collective Narcissism and the 2016 United States Presidential Vote

Explaining support for Donald Trump’s presidential candidacy has become a key social-science challenge. An emerging literature highlights several important individual-level precursors of Trump support, including racial attitudes, sexism, and authoritarianism. In this report, we provide evidence for the role of a novel psychological factor: collective narcissism, an inflated, unrealistic view of the national ingroup’s greatness contingent on external recognition. Using data from a recent national survey, we demonstrate that collective narcissism is a powerful predictor of 2016 presidential votes and evaluations of Trump, even after controlling for other variables known to predict candidate preferences in general and Trump support in particular

100 years after: What is the relation between pacifist attitudes and social representations of the Great War?

In this article we use a social representational perspective on a large sample of European students to consider the interplay between pacifist attitudes and representations of World War I (WWI). WWI gave rise to pacifist movements across the globe. Across 10 European countries (NSCOPUS: ar.jinfo:eu-repo/semantics/publishe

The two-sided role of inclusive victimhood for intergroup reconciliation: evidence from Northern Ireland.

Inclusive victim beliefs (i.e., perceived similarity with other victim groups worldwide) can have positive effects on intergroup relations. However, there may be limitations to these seemingly constructive construals. We investigated in the Northern Irish context whether inclusive victimhood might sometimes also act as an obstacle to intergroup reconciliation. In Study 1, we found that inclusive victimhood can go along with either high or low competitive victimhood and, in turn, with lesser versus greater willingness for reconciliation, respectively. In Study 2, we asked participants which groups they thought about when responding to inclusive victimhood items, coding whether answers suggested a universal or a selective inclusivity. This type of inclusivity moderated the relationships between inclusive victimhood and readiness for reconciliation: Inclusive victimhood correlated positively with intergroup forgiveness when based on a universal notion of inclusivity, and tended to correlate positively with competitive victimhood when based on a selective notion of inclusivity. These results extend the emerging literature on collective victim beliefs and suggest that expressing shared victimization with other groups may be used strategically to strengthen the ingroup\u27s position in an intergroup conflict, which might act as an obstacle to intergroup reconciliation