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To solve the conflict between higher monitoring quality and lower costs of applying Internet of Things(IoT)monitoring system, a mixed integer non-linear programming model is built up. Various key factors, such as network scale, cost, representation level, and deployment of nodes for balance degree of IoT, is taken into consideration in this programming model comprehensively. Furthermore, the quantity and deployment solutions are solved through the genetic algorithm, also the selection of nodes is evaluated. Simulation results show that it is conducive to solve the quality-cost conflict to some extent. It is also of theoretical significance for the IoT research and design of monitoring system. [ABSTRACT FROM AUTHOR]

The energy dissipation capacities and fragments distribution of concrete exposed to high temperature under impact loading are studied. Dynamic compressive tests of concrete at room temperature and after exposure to elevated temperatures ranging from 200 to 800 °C are conducted by using a split Hopkinson pressure bar with 100 mm in diameter. The effects of high temperature and impact velocity on dissipated energy,failure mode and fractal dimension of fragments are analyzed. The results indicate that the dissipated energy grows with the increase in impact velocity and strain rate at the same temperature; and at fixed impact velocity,the dissipated energy decreases with the increase in the exposure temperature. The fragment-size distribution of concrete fragments statistically has fractal property subjected to impact loading. An increase in temperature and impact velocity results in a greater crushing degree and a larger fractal dimension value. There is a positive correlation between dissipated energy and fractal dimension at the same temperature. As a result,the impact crushing of concrete at various temperatures and impact velocities is a fractal evolution process driven by external energy. [ABSTRACT FROM AUTHOR]