Street Stall Economy in China in the COVID-19 Era: Dilemmas and the International Experience of Promoting the Normalization of Street Stall Economy

Compared with those major policies that need to be practiced over the years, the street stall economy is more like a special means after the epidemic, resulting in a “short and brilliant” heat. Nevertheless, the street stall economy revives is facing several dilemmas. This paper reveals the dilemma of the prosperity and development of the stall economy before and after the epidemic, followed by the international experience and enlightenment of promoting the normalization of street stall economy, ranging from street vendor’s legal status and road administrative promotion to street food safety and environmental protection. To sum up, employment is the foundation of people’s livelihood and the source of wealth, hence, stall economy plays an indispensable role to create a win-win working world and promote the formation of a sustainable economic

Generation of nonparaxial self-accelerating beams using pendant droplets

We propose and demonstrate the effectual generation and control of nonparaxial self-accelerating beams by using UV-resin pendant droplets. We show that the geometrical shape of the hanging droplets formed as a result of the interplay between surface tension and gravity offers a natural curvature enabling the generation of nonparaxial self-accelerating beams. By simply adjusting the tilt angle of the surface where the droplets reside, a passing light beam is set to propagate along different curved trajectories, bending into large angles with non-diffracting features superior to a conventional Airy beam. Such self-accelerating beams are directly traced experimentally through the scattered light in yeast-cell suspensions, along with extensive ray tracing and numerical simulations. Furthermore, by modifying the shape of uncured pendant resin droplets in real time, we showcase the dynamical trajectory control of the self-accelerating beams. Our scheme and experimental method may be adopted for droplet-based shaping of other waves such as microfluidic jets and surface acoustic waves.Comment: 8 pages, 8 figures, research articl

Analytical solution for dynamic response of curved rail subjected to moving train

The objective of this paper is to present an analytical solution for the dynamic response of curved rail. The detailed solution was derived for the out-of-plane vibration response of periodically supported curved Timoshenko beam subjected to moving loads. The accuracy of the solution was validated based on the results from previous study. Furthermore, the train/track interaction model was introduced into this solution to calculate the rail dynamic response in Beijing metro. The results presented herein indicated that the solution provided accurate results in comparison with both the result from previous study and the measurement data collected from Beijing metro and it can be used to derive the dynamic response for similar situations

OCC Controller Workload Evaluation Model and Application

AbstractIn order to evaluate and predict OCC controller's mental workload, we defined mental workload as time consumption of task during working time. Five subclasses of workload was found from task analysis in according with five kinds of work task - operation task, recording task, communication task, monitoring task and thinking task, and constructed the suggested workload model of this thesis which was expressed as the sum of consumption time of these five kinds task in a unit time. Then we built the basic task set encoding dictionary and the basic time consumption set to simplify the model, which was based on a larger number of observation behaviors data. At last, time pressure was considered to describe the time constraint effect on mental workload. In the application of validation examine, the subjective evaluation method, the physiological test and the suggested model were used to calculate the time occupancy rate, and results showed a high correlation between the actual and the prediction workload which also proved the validation of the suggested model

Voluntary Disclosure and Information Asymmetry: Evidence from the 2005 Securities Offering Reform

In 2005, the Securities and Exchange Commission enacted the Securities Offering Reform (Reform), which relaxes “gun‐jumping” restrictions, thereby allowing firms to more freely disclose information before equity offerings. We examine the effect of the Reform on voluntary disclosure behavior before equity offerings and the associated economic consequences. We find that firms provide significantly more preoffering disclosures after the Reform. Further, we find that these preoffering disclosures are associated with a decrease in information asymmetry and a reduction in the cost of raising equity capital. Our findings not only inform the debate on the market effect of the Reform, but also speak to the literature on the relation between voluntary disclosure and information asymmetry by examining the effect of quasi‐exogenous changes in voluntary disclosure on information asymmetry, and thus a firm's cost of capital.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/100337/1/joar12022.pd