Revisiting the X-ray emission of the asynchronous polar V1432 Aql

As the only eclipsing asynchronous polar, V1432 Aql provides an excellent laboratory to study the interaction between the accreted matter and the magnetic field. Here, we report an analysis of the X-ray data from the contemporaneous NuSTAR and Swift-XRT observations. The X-ray data present a profile with a low-intensity state for almost half an orbital period, a dip at 0.6 phase, and a peak at 0.75 phase, which suggests that there was only one accretion region during the observation and the claim is supported by the spectral analysis. The comparison with the previous data indicates that the X-ray data have an orbital modulation, as the case in BeppoSAX, rather than a spin one observed in ROSAT. We attribute the orbit and spin modulations to the different accretion geometries at work. The spectral analysis of the wide-band data presents a significant reflection effect, a commonly observed soft X-ray temperature, and the energy balance in V1432 Aql. Additionally, we obtained a low total accretion rate of 1.3 × 10−10 M ⊙ yr−1 and a high specific accretion rate of 3.8 g cm−2 s−1 which explains the strong reflection from the surface of the white dwarf. However, due to its complex emission, a more physical understanding of its accretion geometry is still outstanding.

Gain-loss asymmetry in human experiential tasks

<p>Prospect Theory models behaviour in one-off decisions where outcomes are described. Prospect Theory describes risk aversion when the choice is between gains and risk seeking when the choice is between losses. This asymmetry is known as the reflection effect. In choices about experienced outcomes, individuals show risk seeking for gains and risk aversion for losses. This change in the direction of gain-loss asymmetry is known as the description-experience gap. Across eight experiments, we examined gain-loss asymmetry in two experiential choice procedures. We compared the obtained results with predictions derived from Prospect Theory and the description-experience gap literature. In Study 1, we evaluated the predictions of the reversed reflection effect in probability discounting. Probability discounting is loss in reinforcer value as a function of uncertainty. In typical tasks measuring discounting, participants choose between smaller, certain amounts and a larger amount at one of several probabilities. In choice from description, most participants show a gain-loss asymmetry consistent with the predictions of the reflection effect, discounting gains more steeply than losses. Across three experiments, we examined whether gain-loss asymmetry also occurred when participants experienced the outcomes they chose, when they chose between two uncertain options, and when these two contexts were combined. Across all of the above contexts, no consistent mean difference in discounting of gains and losses was observed. Rather, in most of the tasks that provided experienced outcomes, the participants showed steeper discounting in the first condition completed, whether it involved choices about gains or losses. Furthermore, subsequent conditions produced shallower discounting, but notably, not shallower than choice based on the expected value of the options. In Studies 2 and 3, we followed-up on this order effect by providing the participants with experience of probabilistic outcomes before the discounting tasks. Participants discounted losses more steeply than gains, consistent with the predictions of a reversed reflection effect. In Study 2, we examined gain-loss asymmetry in a rapid-acquisition choice procedure using concurrent variable-interval schedules – the Auckland Card Task. Participants repeatedly chose between two decks of cards that varied in the frequency or magnitude of available gains or losses. Participants were more sensitive to changes in gain than loss frequency between the two decks, consistent with the predictions of a reversed reflection effect, while sensitivity to gain and loss magnitude did not show an asymmetry. We found a novel asymmetry in the local effects of gains and losses. In the frequency tasks, gains disrupted the general pattern of responding more than losses. In the magnitude tasks, varying the magnitude of losses had a bigger effect on local-level patterns following outcomes than varying the magnitude of gains. Across the two tasks we observed patterns of gain-loss asymmetry consistent with the predictions of a reversed reflection effect. We also observed several inconsistencies, particularly when comparing behaviour to choices that would maximize the expected returns. Our research suggested that sufficient exposure to chance outcomes and ensuring delivery of scheduled events are key challenges in further refinement of experiential choice in human operant tasks.</p>

Gain-loss asymmetry in human experiential tasks

<p>Prospect Theory models behaviour in one-off decisions where outcomes are described. Prospect Theory describes risk aversion when the choice is between gains and risk seeking when the choice is between losses. This asymmetry is known as the reflection effect. In choices about experienced outcomes, individuals show risk seeking for gains and risk aversion for losses. This change in the direction of gain-loss asymmetry is known as the description-experience gap. Across eight experiments, we examined gain-loss asymmetry in two experiential choice procedures. We compared the obtained results with predictions derived from Prospect Theory and the description-experience gap literature. In Study 1, we evaluated the predictions of the reversed reflection effect in probability discounting. Probability discounting is loss in reinforcer value as a function of uncertainty. In typical tasks measuring discounting, participants choose between smaller, certain amounts and a larger amount at one of several probabilities. In choice from description, most participants show a gain-loss asymmetry consistent with the predictions of the reflection effect, discounting gains more steeply than losses. Across three experiments, we examined whether gain-loss asymmetry also occurred when participants experienced the outcomes they chose, when they chose between two uncertain options, and when these two contexts were combined. Across all of the above contexts, no consistent mean difference in discounting of gains and losses was observed. Rather, in most of the tasks that provided experienced outcomes, the participants showed steeper discounting in the first condition completed, whether it involved choices about gains or losses. Furthermore, subsequent conditions produced shallower discounting, but notably, not shallower than choice based on the expected value of the options. In Studies 2 and 3, we followed-up on this order effect by providing the participants with experience of probabilistic outcomes before the discounting tasks. Participants discounted losses more steeply than gains, consistent with the predictions of a reversed reflection effect. In Study 2, we examined gain-loss asymmetry in a rapid-acquisition choice procedure using concurrent variable-interval schedules – the Auckland Card Task. Participants repeatedly chose between two decks of cards that varied in the frequency or magnitude of available gains or losses. Participants were more sensitive to changes in gain than loss frequency between the two decks, consistent with the predictions of a reversed reflection effect, while sensitivity to gain and loss magnitude did not show an asymmetry. We found a novel asymmetry in the local effects of gains and losses. In the frequency tasks, gains disrupted the general pattern of responding more than losses. In the magnitude tasks, varying the magnitude of losses had a bigger effect on local-level patterns following outcomes than varying the magnitude of gains. Across the two tasks we observed patterns of gain-loss asymmetry consistent with the predictions of a reversed reflection effect. We also observed several inconsistencies, particularly when comparing behaviour to choices that would maximize the expected returns. Our research suggested that sufficient exposure to chance outcomes and ensuring delivery of scheduled events are key challenges in further refinement of experiential choice in human operant tasks.</p>

UNFILTERED TRAP-BASED PHOTOMETER CALIBRATION

LED-based light sources have replaced massively traditional sources. The metrology traceability chains realised in leading European NMIs utilise the absolutely calibrated broadband radiometers (three-element silicon trap detectors) for calibrating primary photometers. Specific spectral properties of white LED allow to apply the trap detectors directly as new primary photometers. The unfiltered technique (Dӧnsberg at al., 2014) is used and the calibration of spectral irradiance responsivity is needed. We have a long experience in detector-based spectral irradiance responsivity calibrations declared by particular CMC’s published in BIPM KCDB. The aim of this work was to revise the uncertainty budget in order to reduce the measurement uncertainties for specific application of calibration of the trap-based unfiltered primary photometers UPP. The two calibration methods were used to analyse the occasional back-reflection effect of the UPP front aperture. The measurement was performed using our reference spectral responsivity facility in spectral range 350 nm – 900 nm.

XGest: Enabling Cross-Label Gesture Recognition with RF Signals

Extensive efforts have been devoted to human gesture recognition with radio frequency (RF) signals. However, their performance degrades when applied to novel gesture classes that have never been seen in the training set. To handle unseen gestures, extra efforts are inevitable in terms of data collection and model retraining. In this article, we present XGest, a cross-label gesture recognition system that can accurately recognize gestures outside of the predefined gesture set with zero extra training effort. The key insight of XGest is to build a knowledge transfer framework between different gesture datasets. Specifically, we design a novel deep neural network to embed gestures into a high-dimensional Euclidean space. Several techniques are designed to tackle the spatial resolution limits imposed by RF hardware and the specular reflection effect of RF signals in this model. We implement XGest on a commodity mmWave device, and extensive experiments have demonstrated the significant recognition performance.

Influence of Strong Light on the Performance of Piezoresistive Pressure Sensor

It is found that the strong light in the explosion field has great interference to the piezoresistive pressure sensor, then the shock wave data obtained by the sensor is distorted badly. To study the influence mechanism of the strong light on the piezoresistive pressure sensor, a strong light experimental platform is built. The positions of the sensor and the light source are adjusted, and the outputs of the piezoresistive pressure sensor are observed. Through microscopic simulation, the influence of different light intensities on the piezoresistive pressure sensor is analyzed. In order to reduce the influence of strong light on the performance of piezoresistive pressure sensor, we propose to add a reflective layer on the pressure surface of the sensor. The light reflection effects of different film thicknesses are analyzed through film simulation software. At the same time, the reflection effect is verified through experiments. To explain the effect of the reflective layer on the suppression of strong light, a simulation model is established, and the suppression effect of the reflective layer is verified.

Absolute parameters of young stars: PU Pup

We present combined photometric and spectroscopic analyses of the southern binary star PU Pup. High-resolution spectra of this system were taken at the University of Canterbury Mt. John Observatory in the years 2008 and again in 2014–2015. We find the light contribution of the secondary component to be only ∼2% of the total light of the system in optical wavelengths, resulting in a single-lined spectroscopic binary. Recent TESS data revealed grazing eclipses within the light minima, though the tidal distortion, examined also from Hipparcos data, remains the predominating light curve effect. Our model shows PU Pup to have the more massive primary relatively close to filling its Roche lobe. PU Pup is thus approaching the rare ‘fast phase’ of interactive (Case B) evolution. Our adopted absolute parameters are as follows: M 1 = 4.10 (±0.20) M ⊙, M 2 = 0.65 (±0.05) M ⊙, R 1 = 6.60 (±0.30) R ⊙, R 2 = 0.90 (±0.10) R ⊙; T 1 = 11500 (±500) K, T 2 = 5000 (±350) K; photometric distance = 186 (±20) pc, age = 170 (±20) Myr. The less-massive secondary component is found to be significantly oversized and overluminous compared to standard main sequence models. We discuss this discrepancy referring to heating from the reflection effect.

A learning mechanism shaping risk preferences and a preliminary test of its relationship with psychopathic traits

People tend to avoid risk in the domain of gains but take risks in the domain of losses; this is called the reflection effect. Formal theories of decision-making have provided important perspectives on risk preferences, but how individuals acquire risk preferences through experiences remains unknown. In the present study, we used reinforcement learning (RL) models to examine the learning processes that can shape attitudes toward risk in both domains. In addition, relationships between learning parameters and personality traits were investigated. Fifty-one participants performed a learning task, and we examined learning parameters and risk preference in each domain. Our results revealed that an RL model that included a nonlinear subjective utility parameter and differential learning rates for positive and negative prediction errors exhibited better fit than other models and that these parameters independently predicted risk preferences and the reflection effect. Regarding personality traits, although the sample sizes may be too small to test personality traits, increased primary psychopathy scores could be linked with decreased learning rates for positive prediction error in loss conditions among participants who had low anxiety traits. The present findings not only contribute to understanding how decision-making in risky conditions is influenced by past experiences but also provide insights into certain psychiatric problems.

Reflecting on reflection: prospect theory, our behaviors, and our environment

In a previously published article, I reported some tests of prospect theory's reflection effect over outcomes defined by money and life years gained from treatment. Those results suggested qualified support for the reflection effect over money outcomes and strong support over longevity outcomes. This article reruns those tests while accounting for the intensity of individual risk attitudes, and, overall, show consistency with the reflection effect. However, I argue that these results do not necessarily offer support for the explanatory power of prospect theory. Rather, the results may be driven by evolved responses to circumstances that provoke perceptions of scarcity and abundance. Therefore, from an ecological perspective, behavioral patterns such as those that are consistent with the reflection effect, which, by extension, tend to be considered as erroneous or biased by most behavioral economists because they conflict with the postulates of rational choice theory, may not be unreasonable. Recognizing as such is important when considering how behavioral insights ought to inform public policy design and implementation.