Dynamic Interrelation of Births and Deaths: Evidence from Plant Level Data

In this paper, the dynamic panel data method is used to investigate the dynamic interrelation of plant births and plant deaths. The dynamic panel data method considers the endogenous problem and individual effects. Empirical findings support the multiplier effect. In addition, exit does not cause entry, whereas entry causes exit.

From Origin to Delta: Changing Landscape of Modern Constitutionalism

This article deals with the question of whether and to what extent the two forces of democratization and globalization have altered our understandings of constitutionalism. We attempt to theorize a changing landscape of constitutionalism that includes transitional and transnational perspectives and examine respectively their features, functions and characteristics. First, we analyze respective developments of transitional and transnational constitutionalism by identifying their features, perspectives, functions, and characteristics. Then we examine to what extent and in what ways the developments in transitional and transnational constitutionalism pose challenges to our traditional understanding of modern constitutional laws. Finally, we shall picture a new constitutional delta thus emerged and try to argue that notwithstanding challenges, the addition of transitional and transnational constitutionalism to traditional understandings has expanded the horizon of constitutionalism and created new opportunities for a coming generation of constitutional lawyers

Coupled effects of local movement and global interaction on contagion

By incorporating segregated spatial domain and individual-based linkage into the SIS (susceptible-infected-susceptible) model, we investigate the coupled effects of random walk and intragroup interaction on contagion. Compared with the situation where only local movement or individual-based linkage exists, the coexistence of them leads to a wider spread of infectious disease. The roles of narrowing segregated spatial domain and reducing mobility in epidemic control are checked, these two measures are found to be conducive to curbing the spread of infectious disease. Considering heterogeneous time scales between local movement and global interaction, a log-log relation between the change in the number of infected individuals and the timescale $\tau$ is found. A theoretical analysis indicates that the evolutionary dynamics in the present model is related to the encounter probability and the encounter time. A functional relation between the epidemic threshold and the ratio of shortcuts, and a functional relation between the encounter time and the timescale $\tau$ are found

Numerical Simulation on Forced Convection Cooling of Horizontal Ionic Wind with Multi-electrodes

Enhancement ofheat transfer plays an important role in the cooling of electronic or refrigeration systems, and its characteristics could strongly affect the stability and performance of such systems. To enhance heat transfer, air cooling of forced convection remains one of the main solutions. For example, conventional rotary-fan air cooling is still dominant in many areas. However, with the increasing of heat generation in these systems, the limitation of the conventional rotary-fan air cooling is become more obvious. So, demands in novel air cooling technology become necessary, e.g., silent and high efficient air cooling. Recently, ionic wind, which has no moving part and is easily miniaturized, shows great potential in heat dissipation and attracts widespread attentions. In this work, ionic wind, which is produced by wire to plate configuration for forced convection enhancement of horizontal flow along the plate, is numerically investigated. Firstly, a multi-physic model, which accounts for electric field, charge distribution, fluid dynamics, and heat transfer phenomenon, is presented. Comparisons between the simulation and literature data are conducted. Results show that better agreements are achieved by the developed model. Secondly, influences of the emitting electrodes numbers are analyzed. Results show that multiple electrodes configuration has higher performance in terms of heat transfer coefficient than that of the single electrode. Investigations are also carried out on the influences of the distances between the emitting electrodes. Thirdly, effects of the main parameters of ionic wind, such as the inlet velocity, and voltage applied on the electrodes etc., are investigated. Finally, by using the multi-physic model of ionic wind, characteristics of the heat transfer are predicted. It is found that the maximum enhancement of average heat transfer coefficient could reach around 150 %

Developing a Low-Cost Force Treadmill via Dynamic Modeling

By incorporating force transducers into treadmills, force platform-instrumented treadmills (commonly called force treadmills) can collect large amounts of gait data and enable the ground reaction force (GRF) to be calculated. However, the high cost of force treadmills has limited their adoption. This paper proposes a low-cost force treadmill system with force sensors installed underneath a standard exercise treadmill. It identifies and compensates for the force transmission dynamics from the actual GRF applied on the treadmill track surface to the force transmitted to the force sensors underneath the treadmill body. This study also proposes a testing procedure to assess the GRF measurement accuracy of force treadmills. Using this procedure in estimating the GRF of “walk-on-the-spot motion,” it was found that the total harmonic distortion of the tested force treadmill system was about 1.69%, demonstrating the effectiveness of the approach