Direct reconstruction of dynamical dark energy from observational Hubble parameter data

Reconstructing the evolution history of the dark energy equation of state parameter $w(z)$ directly from observational data is highly valuable in cosmology, since it contains substantial clues in understanding the nature of the accelerated expansion of the Universe. Many works have focused on reconstructing $w(z)$ using Type Ia supernova data, however, only a few studies pay attention to Hubble parameter data. In the present work, we explore the merit of Hubble parameter data and make an attempt to reconstruct $w(z)$ from them through the principle component analysis approach. We find that current Hubble parameter data perform well in reconstructing $w(z)$; though, when compared to supernova data, the data are scant and their quality is worse. Both $\Lambda$CDM and evolving $w(z)$ models can be constrained within $10\%$ at redshifts $z \lesssim 1.5$ and even $5\%$ at redshifts 0.1 $\lesssim$ z $\lesssim$ 1 by using simulated $H(z)$ data of observational quality.Comment: 25 pages, 11 figure

Sensor Nodes Deployment Strategy for Monitoring Roadside Biomass Carbon Stocks of Tourism Destination: A Case of Wulong World Natural Heritage, China

Since the late 1978s, China has experienced one of the highest tourism growth rates in the world, which in turn has driven extensive land-use and land-cover change. The aim of this research is to develop a sensor nodes positioning strategy for detecting land use related dynamics of vegetation carbon stocks of Wulong world natural heritage. Based on the assessment of road networks’ influences on biomass carbon stocks, roadside biomass carbon stocks risk index was proposed as a sensor deployment strategy to identify the optimal positions of the sensors to detect the changes in vegetation carbon stocks. Forest and cropland around the lower levels of roads should be the most important region of sensor nodes deployment strategy. The results generated from this study have the ability to achieve optimal solution of spatial positioning problem with minimum number of sensors in biomass carbon monitoring sensor networks. This analysis appears to have great potential for a wide range of practical applications in tourism industry in China

Health shock, medical insurance and financial asset allocation: evidence from CHFS in China

Background: As health care cost is taking an increasingly substantial proportion of national wealth, health shocks and the subsequent medical expenditures have become increasingly vital contributions to financial risks. However, the individual or combined effects of social and financial medical insurance on household financial behaviors are poorly understood. This research aims to examine the effect of health shocks on financial asset mobility and portfolio allocation of the household. Also, whether medical insurance positively affects the financial market will be analyzed. Methods: Linear-regression models are used to determine the relationship between health shock, medical insurance, and household financial behaviors, including liquidity measures and financial portfolio (risk and risk-free assets). Two types of variables (transition probability and upward mobility) are constructed to measure the aggregate-level financial asset mobility. The portfolio of financial assets is categorized according to the risk it bears. Results: Households which experience health shocks are found to exhibit lower transition probability and upward mobility of financial assets than households that do not, and health shocks pose a more serious threat to low-income households. From the inter-temporal perspective, households that have medical insurance exhibit a higher probability of raising their position within the national financial asset distribution, and are more inclined to invest in the risky financial assets. Commercial insurance displays a larger marginal effect on financial asset allocation than social insurance. Our study results highlight an essential link between health shocks, medical insurance, and household financial behavior. Conclusion: This work identified and described the relationship between health-related factors (health shock and two types of medical insurance) and household financial behaviors (risky investment involvement and class mobility in financial asset). A strong link exists between the health and financial market, with heterogenous effects between urban and rural groups, households with distinct income levels, etc. A multilayered insurance system would be helpful to facilitate household income, financial consumption, and economic growth