Southwest University

About: Southwest University is a education organization based out in Chongqing, China. It is known for research contribution in the topics: Gene & Population. The organization has 29772 authors who have published 27755 publications receiving 409441 citations. The organization is also known as: Southwest University in Chongqing & SWU.

The relationships between rumination and core executive functions: A meta-analysis.

Abstract: Background Rumination has been thought to relate to deficits in core executive functions (EFs), but the empirical findings for this idea are mixed. The aim of the present study is to synthesize existing literature to clarify these relations. Methods A comprehensive literature search revealed 34 published as well as unpublished studies on the associations between rumination and core EF. These studies report on 3,066 participants. The effect size in the meta-analyses was obtained by the z transformation of correlation coefficients. Results Analysis revealed significant negative associations between rumination and both inhibition (r = ‒.23) and set-shifting (r = ‒.19). There was no significant association between rumination and working memory. These associations were not moderated by age, sex, type of sample (depressed or healthy), type of outcome measure (accuracy vs. reaction time), or affective content of the task, although statistical power for these tests was limited. Conclusions We found significant negative associations between rumination and inhibition or set-shifting. There was no significant association between rumination and working memory. Future research should adopt multiple measures of EF to provide clear evidence on the associations between EF and rumination. A better understanding of this relationship may have important implications for intervention of rumination, such as training programs to improve EF or teach compensatory strategies to mitigate the effects of EF impairments.

Low-frequency sound absorption of hybrid absorber based on micro-perforated panel and coiled-up channels

Abstract: We propose a hybrid acoustic metamaterial as a super absorber for a relatively broadband low-frequency sound based on a simple construction with deep-subwavelength thickness (5 cm). The hybrid metamaterial absorber is carefully designed and constructed based on a microperforated panel (MPP) and coiled-up Fabry–Perot channels. It is demonstrated analytically, numerically, and experimentally that over 99% of acoustic absorption could be achieved at a resonance frequency (<500 Hz) with the working wavelength about 30 times larger than its total thickness. It is revealed that the superior absorption is mainly caused by the friction losses of acoustic wave energy in the MPP. The frequency of the absorption peak could be tuned by adjusting the geometry parameters of the MPP and the channel folding numbers. The relative absorption bandwidth could also be tuned flexibly (up to 82%) with a fixed deep-subwavelength thickness (5 cm). The absorber has wide potential applications in noise control engineering due to its deep-subwavelength thickness, relatively broad bandwidth, and easy fabrication.

Monitoring Citrus Soil Moisture and Nutrients Using an IoT Based System.

Abstract: Chongqing mountain citrus orchard is one of the main origins of Chinese citrus. Its planting terrain is complex and soil parent material is diverse. Currently, the citrus fertilization, irrigation and other management processes still have great blindness. They usually use the same pattern and the same formula rather than considering the orchard terrain features, soil differences, species characteristics and the state of tree growth. With the help of the ZigBee technology, artificial intelligence and decision support technology, this paper has developed the research on the application technology of agricultural Internet of Things for real-time monitoring of citrus soil moisture and nutrients as well as the research on the integration of fertilization and irrigation decision support system. Some achievements were obtained including single-point multi-layer citrus soil temperature and humidity detection wireless sensor nodes and citrus precision fertilization and irrigation management decision support system. They were applied in citrus base in the Three Gorges Reservoir Area. The results showed that the system could help the grower to scientifically fertilize or irrigate, improve the precision operation level of citrus production, reduce the labor cost and reduce the pollution caused by chemical fertilizer.

Performance Analysis and Optimization for SWIPT Wireless Sensor Networks

Abstract: This paper investigates and optimizes the performance of simultaneous wireless information and power transfer (SWIPT) in wireless sensor networks over Nakagami- $m$ fading channels. In the considered system, there is one mobile reader ( $R$ ), which is equipped with one transmit antenna and one receive antenna, and a group of passive sensors. The information delivery includes two stages: 1) $R$ broadcasts a command with radio-frequency energy to the sensors, which adopt time splitting (TS)/power splitting (PS) schemes to harvest energy and 2) sensors deliver their information to $R$ over orthogonal channels by using the harvested energy. In this paper, we propose a unified framework to study and optimize the impact of SWIPT on the system performance with both TS and PS schemes. First, we characterize the probability density function and cumulative distribution function of the signal-to-interference-plus-noise-ratio in high signal-to-noise ratio region, then we study the outage and ergodic capacity performance of the backward links. The approximated closed-form expressions for the outage probability and ergodic capacity are derived and validated through Monte Carlo simulations. Finally, we also evaluate the energy efficiency of the target system, and propose an optimal splitting scheme for TS and PS to maximize the throughput of the target system.