On Learning Equilibria (Revised June 2003)

We investigate an inflationary overlapping generations model where households predict future inflation rates by running a least squares regression of inflation rates or prices on their past levels. We critically examine the results on learning equilibria obtained by Bullard (1994) and Schönhofer (1999) in this framework. They show that an increase in the money growth rate may lead to limit cycles and endogenous business cycles. We suggest an alternative estimation procedure, that starts from the same perceived law of motion, but is more sensible from an econometrician's point of view. We prove that for this estimation procedure there is global convergence on the monetary steady for a large set of savings functions. We also study, in a heterogeneou agents framework, evolutionary competition between the two estimation procedures, where the fraction of the population using a certain estimation procedure is determined by its past average quadratic forecast error. Interestingly, the more sensible estimation procedure is not always able to drive out the other estimation procedure, and endogenous business cycles may still be observed in this heterogeneous world.

High resolution, low temperature photoabsorption cross-section of C2H2 with application to Saturn's atmosphere

New laboratory observations of the VUV absorption cross-section of C2H2, obtained under physical conditions approximating stratospheres of the giant planets, were combined with IUE observations of the albedo of Saturn, for which improved data reduction techniques have been used, to produce new models for that atmosphere. When the effects of C2H2 absorption are accounted for, additional absorption by other molecules is required. The best-fitting model also includes absorption by PH3, H2O, C2H6 and CH4. A small residual disagreement near 1600 A suggests that an additional trace species may be required to complete the model

Testing a model of global citizenship in higher education institutions in the SADC region

Higher Education Institutions (HEIs) equip the labour force with the necessary skills and knowledge to engage effectively as global citizens. The aim of this study was to test the Reysen and Katzarska-Miller (2013) model of global citizenship identity in the context of HEIs in the SADC region. This study approaches global citizenship from a social identity perspective in which identification as a global citizen is at the center. Identification as a global citizen is theorised to follow a Normative Environment and Global Awareness as antecedents. In turn global citizen identification (GCI) produces six prosocial outcomes. This model proposes nine domains of Global Citizenship including two antecedents, an identification as a global citizen and six prosocial outcomes. Participants included 242 students and staff from universities across seven countries participating in the UNESCO #OpenUpYourThinking Researchers Challenge. Participants completed an online version of the Global Citizenship Scale. In this study, the antecedents and outcomes of GC were all positively and significantly correlated demonstrating a linear relationship between all domains. The results provided empirical support for this model in the context of HEIs in the SADC region. GCI was significantly predicted by normative environment and global awareness. In turn, GCI significantly predicted the six prosocial outcomes. Indirect prediction effects between normative environment, global awareness and GCI significantly predicted the six prosocial outcomes

Mood Worlds: A Virtual Environment for Autonomous Emotional Expression

Immersive interactive technologies such as virtual reality (VR) have the potential to foster well-being. While VR applications have been successfully used to evoke positive emotions through the presetting of light, colour and scenery, the experiential potential of allowing users to independently create a virtual environment (VE) has not yet been sufficiently addressed. To that end, we explore how the autonomous design of a VE can affect emotional engagement and well-being. We present Mood Worlds - a VR application allowing users to visualise their emotions by self-creating a VE. In an exploratory evaluation (N=16), we found that Mood Worlds is an effective tool supporting emotional engagement. Additionally, we found that an autonomous creation process in VR increases positive emotions and well-being. Our work shows that VR can be an effective tool to visualise emotions, thereby increasing positive affect. We discuss opportunities and design requirements for VR as positive technology

Global Sensitivity Analysis of environmental models:Convergence and validation

AbstractWe address two critical choices in Global Sensitivity Analysis (GSA): the choice of the sample size and of the threshold for the identification of insensitive input factors. Guidance to assist users with those two choices is still insufficient. We aim at filling this gap. Firstly, we define criteria to quantify the convergence of sensitivity indices, of ranking and of screening, based on a bootstrap approach. Secondly, we investigate the screening threshold with a quantitative validation procedure for screening results. We apply the proposed methodologies to three hydrological models with varying complexity utilizing three widely-used GSA methods (RSA, Morris, Sobol’). We demonstrate that convergence of screening and ranking can be reached before sensitivity estimates stabilize. Convergence dynamics appear to be case-dependent, which suggests that “fit-for-all” rules for sample sizes should not be used. Other modellers can easily adopt our criteria and procedures for a wide range of GSA methods and cases

Letting It Go: Four Design Concepts to Support Emotion Regulation in Virtual Reality

Depicting emotions, both in reality (e.g. art therapy) and in virtual reality (VR), is an established method for emotion regulation (ER), promoting reflection, behaviour change and mental well-being. However, the specific ways in which users engage with and process negative emotions in VR remains unclear. In this study, we conducted expert interviews with psychotherapists and collaboratively identified design requirements for VR interventions that support the processing of negative emotions. Our findings highlight the potential of VR to facilitate the transition from negative to positive experiences. Based on these findings, we propose specific design concepts for using VR as positive technology for emotion regulation

The Role of Mobile and Virtual Reality Applications to Support Well-Being: An Expert View and Systematic App Review

Interactive technologies for autonomous mental health management are on the rise due to limited therapy access and stigma. However, most commercial mental health apps are neither theory-based nor clinically tested, and psychological theories are not easily accessible to app designers. Thus, it remains unclear if current mobile and VR mental health apps meet therapists’ expectations. To address this gap, we conducted interviews (N=11 ) to build an understanding about current therapeutic practices with a focus on emotion regulation and their applicability to mobile apps. We then conducted a systematic app review of 60 mental-health-related mobile and VR apps applying the themes identified in our interviews as an understanding lens. We draw upon the identified discrepancies to pinpoint design implications for better embedding lived therapeutic practice into mental health apps. We contribute by providing a common grounding between therapists and developers on the features and properties of well-being mobile and VR apps

Evaluation of the two-photon absorption characteristics of GaSb/GaAs quantum rings

The optical parameters describing the sub-bandgap response of GaSb/GaAs quantum rings solar cells have been obtained from photocurrent measurements using a modulated pseudomonochromatic light source in combination with a second, continuous photo-filling source. By controlling the charge state of the quantum rings, the photoemission cross-sections describing the two-photon sub-bandgap transitions could be determined independently. Temperature dependent photo-response measurements also revealed that the barrier for thermal hole emission from the quantum rings is significantly below the quantum ring localisation energy. The temperature dependence of the sub-bandgap photo-response of the solar cell is also described in terms of the photo-and thermal-emission characteristics of the quantum rings. (C) 2014 AIP Publishing LLC