Real nonparametric regression using complex wavelets

Summary.  Wavelet shrinkage is an effective nonparametric regression technique, especially when the underlying curve has irregular features such as spikes or discontinuities. The basic idea is simple: take the discrete wavelet transform of data consisting of a signal corrupted by noise; shrink or remove the wavelet coefficients to remove the noise; then invert the discrete wavelet transform to form an estimate of the true underlying curve. Various researchers have proposed increasingly sophisticated methods of doing this by using real-valued wavelets. Complex-valued wavelets exist but are rarely used. We propose two new complex-valued wavelet shrinkage techniques: one based on multiwavelet style shrinkage and the other using Bayesian methods. Extensive simulations show that our methods almost always give significantly more accurate estimates than methods based on real-valued wavelets. Further, our multiwavelet style shrinkage method is both simpler and dramatically faster than its competitors. To understand the excellent performance of this method we present a new risk bound on its hard thresholded coefficients.     

Modelling map positional error to infer true feature location

The authors consider the issue of map positional error, or the difference between location as represented in a spatial database (i.e., a map) and the corresponding unobservable true location. They propose a fully model‐based approach that incorporates aspects of the map registration process commonly performed by users of geographic informations systems, including rubber‐sheeting. They explain how estimates of positional error can be obtained, hence estimates of true location. They show that with multiple maps of varying accuracy along with ground truthing data, suitable model averaging offers a strategy for using all of the maps to learn about true location.     

Domains, ranges and strategy-proofness: the case of single-dipped preferences

We characterize the set of all individual and group strategy-proof rules on the domain of all single-dipped preferences on a line. For rules defined on this domain, and on several of its subdomains, we explore the implications of these strategy-proofness requirements on the maximum size of the rules’ range. We show that when all single-dipped preferences are admissible, the range must contain two alternatives at most. But this bound changes as we consider different subclasses of single-dipped preferences: we provide examples of subdomains admitting strategy-proof rules with larger ranges. We establish exact bounds on the maximal size of strategy-proof functions on each of these domains, and prove that the relationship between the sizes of the subdomains and those of the ranges of strategy-proof functions on them need not be monotonic. Our results exhibit a sharp contrast between the structure of strategy-proof rules defined on subdomains of single-dipped preferences and those defined on subsets of single-peaked ones.     

Emotional Intimacy Power Predicts Different Sexual Experiences for Men and Women

Those who are more emotionally invested in relationships have less power than their partners. Furthermore, less powerful individuals may attempt to equalize power imbalances by offering rewards to their partner and using sex and condom use as exchange resources. Australian young adults reported their condom use and pressured sex experiences in both romantic (n = 708) and casual (n = 118) relationships. Results showed that greater power (lower relative emotional investment) predicted more condom use among those wanting to use condoms. In casual relationships, an interaction with gender showed that women in particular used condoms more when they had more power. Power also interacted with gender for pressured sex and, unexpectedly, men who had more power experienced more pressured sex. The possibility that condom use and pressured sex have different meanings for men and women is explored.     

High Educational Aspirations Among Pregnant Adolescents Are Related to Pregnancy Unwantedness and Subsequent Parenting Stress and Inadequacy

On the basis of theories of maternal identity development, role conflict, and childbearing motivation, the authors tested whether high educational aspirations among pregnant adolescents are related to the unwantedness of the pregnancy and whether pregnancy unwantedness leads to subsequent parenting stress and inadequacy. Longitudinal data from 100 first‐time‐pregnant, unmarried Latina adolescents (M age = 17.3 years) were analyzed. Results from structural equation path modeling confirmed these associations, with strong educational ambitions related to greater unwantedness of the pregnancy, which led to feeling trapped by parenting at 6 months postpartum, which in turn was related to unaffectionate parenting and feeling inadequate in mothering at 1 year postpartum. The potential long‐term negative consequences of high educational aspirations for pregnant adolescents' adjustment to parenting are discussed.     

Temporal Patterns of Accuracy Confidence in Social Judgments: A New Method and Initial Results

An integrated, computer-based system was developed to record participants’ continuous judgment changes on a revised form of the Interpersonal Perception Task (IPT-15). Consistent with the considerable research on “thin slice” judgments, the mean latency for greater than chance accuracy confidence was just 16 s (median = 10 s) for the ten one-part scenes on the IPT. There was also a clear and strong linear trend for increasing accuracy confidence across the first 25 s of the ten one-part scenes. For the five-two-part scenes, where comparative judgments were required (e.g., which statement is truthful, which is a lie?), no clear pattern of increasing accuracy confidence was found, with mean scores hovering near chance. The utility of the new system for analyzing the time course of social judgments is discussed and the potential reasons for the contrasting results for the one-part and two-part scenes were examined.     

Chinese,Japanese or ‘Oriental’?: Vietnamese-passing in ‘super-diverse’ London

The young British-born Vietnamese are a relatively invisible group in ‘super-diverse’ London who are often misidentified in their everyday encounters. Eluding more straightforward processes of ethnic or racial assignment, the young Vietnamese ‘pass’ in various different ways as Chinese, Japanese, Korean, Thai or ‘Oriental’. Drawing upon primary interview data and participant observation, this article traces ‘passive’ and ‘deliberate’ forms of passing to highlight how intersecting processes of class, gender and place enable/engender different kinds of passing. It is argued that Vietnamese-passing challenges more ‘celebratory’ readings of (super-) diversity by concealing (and depoliticising) difference and erasing Vietnamese voices rather than allowing for their proliferation. It is suggested that practices of passing may become more common in super-diverse societies, as markers of visible difference become increasingly complex and less determinable, especially among newer, non-colonial migrant groups who are more ambiguously positioned within existing identity regimes.     

Environmental Effects on Family Size Preferences and Subsequent Reproductive Behavior in Nepal

This study investigates the relationship between environmental degradation and men and womens family size preferences and subsequent reproductive behaviors in Nepal. We draw on unique environmental data at the local level, household and individual-level survey data and individuals reproductive behavior over a 3 year time period in Western Chitwan Valley, Nepal. Results from Ordinary Least Squares (OLS) and logistic regression models show that poorer environmental quality and greater reliance on publicly owned natural resources are associated with higher family size preferences and higher rates of pregnancy. The analyses provide support for the vicious circle argument that environmental degradation can lead to rising population growth via positive effects on fertility. As environmental conditions decline and when households rely on public lands for natural resources, men and women desire larger family sizes and women are more likely to get pregnant in the near future.