Migration in towns in China, a tale of three provinces : evidence from preliminary tabulations of 2000 census

There is a concern that the growth of towns in China has been stalled recently and with it, the creation of nonfarm jobs in rural industries. The author uses the 2000 census tabulations to look at this issue by examining in-migration in towns in three provinces in China-Zhejiang, Henan, and Sichuan-their educational attainment, original place, and occupational composition. In addition to the diversified patterns of town in-migrants revealed in the three provinces, the author finds that town in-migrants generallypossess a higher level of educational attainment than the local population in towns, especially in the less developed western and central regions. This inflow of human capital could foster development in towns. There is also evidence that as economic opportunity increases in towns, such as in richer coastal province of Zhejiang, better educated people in rural areas are likely to shift their jobs from the farm to the nonfarm sector in towns nearby, instead of leaving the countryside to migrate to other provinces. This could reduce migration pressure on big cities. Finally, the labor market in towns in the less developed west and central regions is more flexible in accommodating in-migrants, whereas in the developed province of Zhejiang the labor market is segregated between migrants and the local population.Anthropology,Town Water Supply and Sanitation,Labor Markets,Voluntary and Involuntary Resettlement,Human Migrations&Resettlements

How access to urban potable water and sewerage connections affects child mortality

Using a city-level database of global Urban Indicators, the author finds that: 1) Improved access to urban potable water and sewerage connections is consistently associated with low child mortality. 2) Government involvement in providing water services, especially locally, significantly reduces child mortality. 3) Private or parastatal participation in providing sewerage connections is associated with low child mortality. $) Rapid urban growth and high levels of poverty within the city are correlated with high child mortality.Health Economics&Finance,Public Health Promotion,Decentralization,Demographics,Environmental Economics&Policies,Town Water Supply and Sanitation,Urban Water Supply and Sanitation,City Development Strategies,Health Economics&Finance,Water and Industry

Robust c-Optimal Design for Estimating the Edp

Optimal design provides the most efficient design to study dose-response functions. It is often observed to adopt the four-parameter logistic model to describe the dose-response relationships in many dose finding trials. Under the four-parameter logistic model, optimal design to estimate the EDp accurately is presented. The EDp is the dose achieving 100p% of the maximum treatment effect. C-optimal design works the best to estimate the EDp, but the value of p must be predetermined in order to obtain the c-optimal design. Here we investigate the efficiency of c-optimal design to estimate the EDp for different values of p and present robust c-optimal design that works well for the changes in the value of p. Five different values of p are considered in this study: ED10, ED30, ED50, ED70, and ED90. The performance of the robust c-optimal design is obtained and compared to the c-optimal designs and traditional uniform designs

Reconstruction of three-dimensional turbulent flow structures using surface measurements for free-surface flows based on a convolutional neural network

A model based on a convolutional neural network (CNN) is designed to reconstruct the three-dimensional turbulent flows beneath a free surface using surface measurements, including the surface elevation and surface velocity. Trained on datasets obtained from the direct numerical simulation (DNS) of turbulent open-channel flows with a deformable free surface, the proposed model can accurately reconstruct the near-surface flow field and capture the characteristic large-scale flow structures away from the surface. The reconstruction performance of the model, measured by metrics such as the normalised mean squared reconstruction errors and scale-specific errors, is considerably better than that of the traditional linear stochastic estimation (LSE) method. We further analyse the saliency maps of the CNN model and the kernels of the LSE model and obtain insights into how the two models utilise surface features to reconstruct subsurface flows. The importance of different surface variables is analysed based on the saliency map of the CNN, which reveals knowledge about the surface-subsurface relations. The CNN is also shown to have a good generalization capability with respect to the Froude number if a model trained for a flow with a high Froude number is applied to predict flows with lower Froude numbers. The results presented in this work indicate that the CNN is effective regarding the detection of subsurface flow structures and by interpreting the surface-subsurface relations underlying the reconstruction model, the CNN can be a promising tool for assisting with the physical understanding of free-surface turbulence

Numerical study of mixed-phase ice crystal icing based on Eulerian method

Ice crystals mainly cause compressor blades icing, and it is difficult to reveal the icing mechanism by experimental methods. Therefore, an Eulerian method was used to study ice crystal icing on a wedge airfoil in this paper. The calculation process was divided into three parts. First, the air flow field was calculated by Spalart-Allmaras turbulence model. Then the Eulerian method was used to obtain the trajectory of ice crystal and droplet. At last, the Messinger model was used to calculate the ice shape. The feasibility of the numerical method was verified by the NRC’s experiments. Then the effect of pressure on icing was analyzed. It could be found that the lower the pressure, the stronger the sublimation (evaporation) of ice crystals (droplets), and the more obvious the icing was. In addition, the ratio of LWC/TWC (Liquid Water Content/ Total Water Content) had a great effect on icing. It also could be found that too little or too much liquid water was not conductive for icing. The conclusions obtained by calculation were basically consistent with the NRC’s. The method in this paper could provide some reference for the subsequent study of engine icing mechanism or the design of anti-icing system.Peer Reviewe

Electrical properties of double layer dielectric structures for space technology

Effects of space environment -- Protection of thermal blankets -- Electrical conduction mechanisms in dielectrics -- Molecular structure of polymers -- Electrical conduction mechanisms in polymers -- Properties of polyimide -- Properties of poly(ethylene terephthalate) -- Electron-beam charging of polymers -- Experimental methodology -- The samples for conductivity measurements -- The samples for C-V measurements -- Electrical measurements -- Measurements of d.c. bulk and surface conductivities -- Measurements of the C-V characteristics -- D.C. electrical conduction results -- Characteristic measurements

Incremental validity of character measures over the big five inventory in predicting academic achievement

Educationally contextualized character skills, such as grit, need for cognition, intellectual self-concept, mastery orientation, school value, and growth mindset, are important predictors of academic achievement. Yet, it remains unclear to what extent these proposed measures provide additional theoretical or empirical utility over established measures of general personality, such as the Big Five. Here, we examine whether character measures display incremental validity over and above the Big Five Inventory and measures of cognitive ability when predicting academic performance. Using a large sample (N = 1,054) of 3rd through 8th grade students, we applied structural equation modeling to partition unique and common predictive power of character measures. The results indicate that multiple character measures demonstrate incremental prediction over and above the Big Five Inventory and cognitive ability. The character measures of need for cognition (ΔR2=7.3% over personality, ΔR2=6.4% over personality and cognitive ability) and school value (ΔR2=8.0%, ΔR2=5.6%) displayed the largest incremental validity. Furthermore, the incremental predictive power of character was shared within the domain of character, except for a unique effect of school value. Multiple psychological dimensions are uniquely associated with academic achievement