P300 and Decision Making under Risk and Ambiguity

Our study aims to contrast the neural temporal features of early stage of decision making in the context of risk and ambiguity. In monetary gambles under ambiguous or risky conditions, 12 participants were asked to make a decision to bet or not, with the event-related potentials (ERPs) recorded meantime. The proportion of choosing to bet in ambiguous condition was significantly lower than that in risky condition. An ERP component identified as P300 was found. The P300 amplitude elicited in risky condition was significantly larger than that in ambiguous condition. The lower bet rate in ambiguous condition and the smaller P300 amplitude elicited by ambiguous stimuli revealed that people showed much more aversion in the ambiguous condition than in the risky condition. The ERP results may suggest that decision making under ambiguity occupies higher working memory and recalls more past experience while decision making under risk mainly mobilizes attentional resources to calculate current information. These findings extended the current understanding of underlying mechanism for early assessment stage of decision making and explored the difference between the decision making under risk and ambiguity

Experimental observation of effect of the wall curvature of capillary tube on colloidal crystallization inside the tube

We investigated the crystallization process of colloidal suspensions in capillary tubes with different curvature radius. The evolution of structural parameters during crystallization such as crystallinity, average crystallites size and number of crystallites were determined by the reflection spectrum combined with a specially developed data-handling method. We found that the wall curvature has a significant effect on fluctuation, thus the stability of the structural parameters during crystallization process, and with the decrease of the curvature, this effect quickly weakens. In addition, our experiments showed the concentration has lithe influence on crystal stability

XX An Asymmetric Dual-Processor Architecture for Low Power Information Appliances

As users become increasingly conscious of their energy footprint—either to improve battery life or to respect the environment—improved energy efficiency of systems has gained in importance. This is especially important in the context of information appliances such as Ebook readers that are meant to replace books, since their energy efficiency impacts how long the appliance can be used on a single charge of the battery. In this paper, we present a new software and hardware architecture for information appliances that provides significant advantages in terms of device lifetime. The architecture combines a low power microcontroller with a high-performance application processor, where the low power micro-controller is used to handle simple user interactions (e.g., turning pages, inking, entering text) without waking up the main application processor. We demonstrate how this architecture is easily adapted to the traditional way of building user interfaces using a user interface markup language. We report on our initial measurements using an E-ink-based prototype. When comparing our hybrid architecture to a simpler solution we found that we can increase the battery life by a factor of 1.72 for a reading task, and by a factor of 3.23 for a writing task. We conclude by presenting design guidelines aimed at optimizing the overall energy signature of information appliances

A Precise Prediction of Tunnel Deformation Caused by Circular Foundation Pit Excavation

In comparison with tetragonal retaining structures, circular retaining structures have an advantage in terms of controlling the deformation caused by foundation excavation, and are a reasonable choice in engineering practice. Many results have been obtained regarding the effect of tetragonal excavation on the deformation of an adjacent tunnel. Nevertheless, a sufficient understanding of the circular excavation’s effect on the deformation of an adjacent tunnel is currently lacking. Therefore, this study focused on the problem of precise predicting tunnel deformation below a circular excavation. A numerical model was established to calculate the tunnel deformation caused by the circular excavation. An advanced nonlinear constitutive model, known as a hypoplasticity model, which can capture path-dependent and strain-dependent soil stiffness even at small strains, was adopted. The models and their associated parameters were calibrated by centrifuge test results reported in the literature. The deformation mechanism was revealed, and the calculated results were compared with those obtained with a square excavation and the same excavation amount. The differences between the deformations caused by these two types of excavation shapes were analyzed. It was found that under equal excavation area conditions, the excavation-induced deformations of the metro tunnel below a circular excavation were approximately 1.18–1.22 times greater than those below a square excavation. The maximum tunnel tensile bending strain caused by the circular excavation was 32% smaller than that caused by the square excavation. By comparing with the measured results, it is proved that the proposed numerical method can provide effective reference for engineers to analyze soil-structure problems

Analysis of Elastoplastic Mechanical Properties of Non-Uniform Frozen Wall Considering Frost Heave

The aim of this study was to analyze the force and deformation law of an artificial frozen wall. Thus, the frost heave coefficient was introduced to describe the frost heave characteristics, and the frozen wall was regarded as a heterogeneous material whose material properties changed in a parabolic pattern with the radius. The elastoplastic stress and displacement formulas of a non-uniform frozen wall considering frost heave characteristics were derived according to different strength criteria. Consequently, the derived formulas were used to calculate and analyze the mechanical characteristics of the artificial frozen wall. The results showed that the radial stress of the frozen wall changed linearly, whereas the circumferential stress change followed a parabolic pattern after considering the non-uniform characteristics. Moreover, the displacement of the outer edge of the frozen wall was always greater than that of the inner edge, and the displacement of the inner edge changed with the increasing temperature, significantly greater than that of the outer edge. When the frozen wall was in the elastic state, its displacement caused by frost heave was constant. When the frozen wall entered the elastic–plastic state, the displacement of its inner edge caused by frost heave increased with the increase in the radius of the plastic zone, whereas the displacement of the outer edge caused by frost heave decreased with the increase in the radius of the plastic zone