The inversion effect on gaze perception reflects processing of component information

When faces are turned upside-down they are much more difficult to recognize than other objects. This "face inversion effect” has often been explained in terms of configural processing, which is impaired when faces are rotated away from the upright. Here we report a "gaze inversion effect” and discuss whether it is related to configural face processing of the whole face. Observers reported the gaze locations of photographed upright or inverted faces. When whole faces were presented, we found an inversion effect both for constant errors and observer sensitivity. These results were closely replicated when only the eyes were visible. Together, our findings suggest that gaze processing is largely based on component-based information from the eye region. Processing this information is orientation-sensitive and does not seem to rely on configural processing of the whole fac

IFNN Manual: Integrated Framework for Neural Network and Conventional Modelling

Series: Research Reports of the Institute for Economic Geography and GIScienc

The Limits to Buying Stability in Tibet: Tibetan Representation and Preferentiality in China's Contemporary Public Employment System

Based on an entirely unexplored source of data, this paper analyses the evolution of Tibetan representation and preferentiality within public employment recruitment across all Tibetan areas from 2007 to 2015. While recruitment collapsed after the end of the job placement system (fenpei) in the early to mid-2000s, there was a strong increase in public employment recruitment from 2011 onwards. Tibetans were underrepresented within this increase, although not severely, and various implicit practices of preferentiality bolstered such representation, with distinct variations across regions and time. The combination reasserted the predominant role of the state as employer of educated millennials in Tibetan areas to the extent of re-introducing employment guarantees. We refer to this as the innovation of a neo-fenpei system. This new system is most clearly observed in the Tibet Autonomous Region (TAR) from 2011 to 2016, although it appears to have been abandoned in 2017. One effect of neo-fenpei, in contrast to its predecessor, is that it accentuates university education as a driver of differentiation within emerging urban employment. The evolution of these recruitment practices reflects the complex tensions in Tibetan areas regarding the overarching goal of security and social stability (weiwen) emphasized by the Xi–Li administration, which has maintained systems of minority preferentiality but in a manner that enhances assimilationist trends rather than minority group empowerment

SIM User's Manual. A Flexible Toolbox for Spatial lnteraction Modelling.

Series: Research Reports of the Institute for Economic Geography and GIScienc

The evolution of Tibetan representation and preferentiality in public employment during the Post-fenpei period in China: Insights from new data sources

This paper exploits a new and exciting source of data on public employment recruitment in order to analyse the evolution of Tibetan representation and preferential hiring practices in public employment in all Tibetan areas from 2007 to 2015. Despite the limitations of these data, they provide a far more substantiated understanding of recent conditions than currently exists in the literature, even in the Chinese literature. Several major insights can be made from scrutinizing these data. First, following the retrenchment in public employment in the early 2000s and then the ending of the job placement system (Ch. fenpei), there was a strong increase in public employment recruitment from 2011 onwards. Second, Tibetan representation within the recruitment did not collapse, although it lagged significantly; within our sample of outcome documents, Tibetans were underrepresented in the recruitments across all Tibetan areas from 2007 to 2015, without any apparent regional or temporal patterns, at an average of 83 percent of what would be parity with their population share. More information is also needed on the ethnic composition of people exiting from public employment in order to have a more holistic evaluation of the evolution of Tibetan representation. Nonetheless, despite underrepresentation, new recruitment from 2011 onwards employed a much larger share of the university-aged population than during the late fenpei period, thereby reasserting the role of the state as predominant employment provider for educated Tibetan millennials. Practices of preferentiality appear to significantly bolster representation, although they exhibited distinct temporal and regional variations. Language or Tibetan medium degree type requirements were generally on the decline (especially in the TAR and Gannan, where their use became very marginal), with the exception of the Amdo region in Qinghai. Conversely, the use of residency requirements across all Tibetan regions has emerged as a significant form of practicing preferentiality in public employment, especially in the Tibet Autonomous Region (TAR), where all public sector recruitments specify local ‘origin’ (Ch. shengyuan) since at least 2007. The TAR also reintroduced employment guarantees for all local university graduates in 2011, in what we call the innovation of a neo-fenpei system. The decline in the use of linguistic requirements suggests the continuation and entrenchment of assimilationist trends in education and employment policies, and a lack of priority for Tibetan medium education more generally (with the exception of the Amdo region in Qinghai). However, the stable and in some cases increasing use of residency requirements, especially in civil service positions suggests a trend of local level protectionism in public employment, probably led by local governments

Feedback-related EEG dynamics separately reflect decision parameters, biases, and future choices

Optimal decision making in complex environments requires dynamic learning from unexpected events. To speed up learning, we should heavily weight information that indicates state-action-outcome contingency changes and ignore uninformative fluctuations in the environment. Often, however, unrelated information is hard to ignore and can potentially bias our learning. Here we used computational modelling and EEG to investigate learning behaviour in a modified probabilistic choice task that introduced two task-irrelevant factors that were uninformative for optimal task performance, but nevertheless could potentially bias learning: pay-out magnitudes were varied randomly and, occasionally, feedback presentation was enhanced by visual surprise. We found that participants’ overall good learning performance was biased by distinct effects of these non-normative factors. On the neural level, these parameters are represented in a dynamic and spatiotemporally dissociable sequence of EEG activity. Later in feedback processing the different streams converged on a central to centroparietal positivity reflecting a signal that is interpreted by downstream learning processes that adjust future behaviour

Modified Method of Moments for Generalized Laplace Distribution

In this note, we consider the performance of the classic method of moments for parameter estimation of symmetric variance-gamma (generalized Laplace) distributions. We do this through both theoretical analysis (multivariate delta method) and a comprehensive simulation study with comparison to maximum likelihood estimation, finding performance is often unsatisfactory. In addition, we modify the method of moments by taking absolute moments to improve efficiency; in particular, our simulation studies demonstrate that our modified estimators have significantly improved performance for parameter values typically encountered in financial modelling, and is also competitive with maximum likelihood estimation.Comment: 18 page

The Variance-Gamma Distribution: A Review

The variance-gamma (VG) distributions form a four-parameter family which includes as special and limiting cases the normal, gamma and Laplace distributions. Some of the numerous applications include financial modelling and distributional approximation on Wiener space. In this review, we provide an up-to-date account of the basic distributional theory of the VG distribution. Properties covered include probability and cumulative distribution functions, generating functions, moments and cumulants, mode and median, Stein characterisations, representations in terms of other random variables, and a list of related distributions. We also review methods for parameter estimation and some applications of the VG distribution, including the aforementioned applications to financial modelling and distributional approximation on Wiener space.Comment: 31pages, 3 figure

Requirements and a Meta Model for Exchanging Additive Manufacturing Capacities

In an environment shaped by digital transformation and globalization, manufacturers face increasing market dynamics, cost pressure, and more sophisticated customer requirements. As this demands flexibility and adaptability, enterprises rely on new solutions for collaboration. A marketplace for production capacities supports companies in reducing order risks and improving responsiveness to changing market conditions. We seek to define requirements for a marketplace that is capable of matching products with production processes. With an initial focus on additive manufacturing, we aim to build a blueprint for similar application scenarios in other industrial contexts. Therefore, we employ a qualitative research based on expert interviews. Our results suggest that a marketplace for production capacities must address various requirements, which can be grouped under the categories of technologies, machines, and products. We further build a conceptual meta model that sets the groundwork for the matching and thus facilitates the implementation of the marketplace in practice

Normal approximation for the posterior in exponential families

In this paper we obtain quantitative Bernstein-von Mises type bounds on the normal approximation of the posterior distribution in exponential family models when centering either around the posterior mode or around the maximum likelihood estimator. Our bounds, obtained through a version of Stein's method, are non-asymptotic, and data dependent; they are of the correct order both in the total variation and Wasserstein distances, as well as for approximations for expectations of smooth functions of the posterior. All our results are valid for univariate and multivariate posteriors alike, and do not require a conjugate prior setting. We illustrate our findings on a variety of exponential family distributions, including Poisson, multinomial and normal distribution with unknown mean and variance. The resulting bounds have an explicit dependence on the prior distribution and on sufficient statistics of the data from the sample, and thus provide insight into how these factors may affect the quality of the normal approximation. The performance of the bounds is also assessed with simulations