As blockchain technology booms, modern electronic voting system leverages blockchain as underlying storage model to make the voting process more transparent, and guarantee immutability of data. However, the transparent characteristic may disclose sensitive information of candidate for all system users have the same right to their information. Besides that, the pseudo-anonymity of blockchain will lead to the disclosure of voters’ privacy and the third-parties such as registration institutions involved in voting process also have possibility of tampering data. To overcome these difficulties, we apply authority management mechanism into blockchain-based voting systems. In this paper, we put forward AMVchain, a fully decentralized and efficient blockchain-based voting system. AMVchain has a three-layer access control architecture, and on each layer, smart contracts are responsible for validation and granting permissions. Linkable ring signature is adopted in the process of voting to protect ballot-privacy. AMVchain also makes a tradeoff between efficiency and concurrency by introducing proxy nodes. The experiments results show that our system meets the basic requirements under the high concurrent users circumstance.

To advance the development of piezoelectric energy harvesters, this study designed and manufactured bridge-unit-based and pile-unit-based piezoelectric devices. An indoor material testing system and accelerated pavement test equipment were used to test the electrical performance, mechanical performance, and electromechanical coupling performance of the devices. The results showed that the elastic modulus of the pile structure device was relatively higher than that of the bridge structure device. However, the elastic modulus of the two devices should be improved to avoid attenuation in the service performance and fatigue life caused by the stiffness difference. Furthermore, the electromechanical conversion coefficients of the two devices were smaller than 10% and insensitive to the load magnitude and load frequency. Moreover, the two devices can harvest 3.4 mW and 2.6 mW under the wheel load simulated by the one-third scale model mobile load simulator, thus meeting the supply requirements of low-power sensors. The elastic modulus, electromechanical conversion coefficients, and electric performance of the pile structure device were more reliable than those of the bridge structure device, indicating a better application prospect in road engineering.

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The development and utilization of renewable energy, especially solar energy, is an important way to solve the problem that China’s rural conventional power grids cannot cover remote rural areas. It is also an inevitable requirement of China’s rural development strategy. This article explores the influencing factors of Chinese farmers’ vigorous promotion of the use of solar houses, studies relationships among perceived value, farmer’s attitude and willingness to convert traditional houses into solar houses. Using data collected by a questionnaire from 413 rural households in Chongqing, China, the results show that perceived value has a significant and positive effect on farmer’s attitude and willingness to convert traditional houses into solar houses. Most importantly, the results of this research show that farmers’ attitude partially mediates the effects of perceived value on willingness to convert. Finally, the study also proposes relevant suggestions for policy makers, marketing managers and further research.