Study of blasting vibration safety security criterion method based on response spectrum

AbstractBased on lots of blasting vibration monitoring data, correlation analysis on blasting vibration velocity response spectrum SR and blasting seismic waves with each signal characteristic, research that SR has damage and associated influence on building structure vibration. Research found that SR can reflect the values of the comprehensive effect of blasting vibration, and the dynamic characteristics of the influence of structural vibration. According to the research results, this paper puts forward with SR as blasting vibration safety assessment criterion of new methods

CoRide: Joint Order Dispatching and Fleet Management for Multi-Scale Ride-Hailing Platforms

How to optimally dispatch orders to vehicles and how to tradeoff between immediate and future returns are fundamental questions for a typical ride-hailing platform. We model ride-hailing as a large-scale parallel ranking problem and study the joint decision-making task of order dispatching and fleet management in online ride-hailing platforms. This task brings unique challenges in the following four aspects. First, to facilitate a huge number of vehicles to act and learn efficiently and robustly, we treat each region cell as an agent and build a multi-agent reinforcement learning framework. Second, to coordinate the agents from different regions to achieve long-term benefits, we leverage the geographical hierarchy of the region grids to perform hierarchical reinforcement learning. Third, to deal with the heterogeneous and variant action space for joint order dispatching and fleet management, we design the action as the ranking weight vector to rank and select the specific order or the fleet management destination in a unified formulation. Fourth, to achieve the multi-scale ride-hailing platform, we conduct the decision-making process in a hierarchical way where a multi-head attention mechanism is utilized to incorporate the impacts of neighbor agents and capture the key agent in each scale. The whole novel framework is named as CoRide. Extensive experiments based on multiple cities real-world data as well as analytic synthetic data demonstrate that CoRide provides superior performance in terms of platform revenue and user experience in the task of city-wide hybrid order dispatching and fleet management over strong baselines.Comment: CIKM 201

Evaluation of the deposition and distribution of spray droplets in citrus orchards by plant protection drones

Plant protection drone spraying technology is widely used to prevent and control crop diseases and pests due to its advantages of being unaffected by crop growth patterns and terrain restrictions, high operational efficiency, and low labor requirements. The operational parameters of plant protection drones significantly impact the distribution of spray droplets, thereby affecting pesticide utilization. In this study, a field experiment was conducted to determine the working modes of two representative plant protection drones and an electric backpack sprayer as a control to explore the characteristics of droplet deposition with different spray volumes in the citrus canopy. The results showed that the spraying volume significantly affected the number of droplets and the spray coverage. The number of droplets and the spray coverage area on the leaf surface were significantly increased by increasing the spray volume from 60 L/ha to 120 L/ha in plant protection drones. Particularly for the DJI T30, the mid-lower canopy showed a spray coverage increase of 52.5%. The droplet density demonstrated the most significant variations in the lower inner canopy, ranging from 18.7 droplets/cm2 to 41.7 droplets/cm2 by XAG V40. From the deposition distribution on fruit trees, the plant protection drones exhibit good penetration ability, as the droplets can achieve a relatively even distribution in different canopy layers of citrus trees. The droplet distribution uniformity inside the canopy is similar for XAG V40 and DJI T30, with a variation coefficient of approximately 50%-100%. Compared to the plant protection drones, the knapsack electric sprayer is suitable for pest and disease control in the mid-lower canopy, but they face challenges of insufficient deposition capability in the upper canopy and overall poor spray uniformity. The distribution of deposition determined in this study provides data support for the selection of spraying agents for fruit trees by plant protection drones and for the control of different pests and diseases

Experimental study on flow-induced motion and energy conversion for two triangular prisms in tandem arrangement

Experimental tests on two tandem triangular prisms were accomplished in synergistic flow-induced motion (FIM) to collect ocean current energy (OCE) with varied spacing ratios and Reynolds number ranges. Typical FIM responses and energy conversion are discussed and presented. The effects of parameters (system stiffness, spacing ratio, and load resistance) were considered to improve the energy harvesting of the system. The main findings can be summarized as follows: 1) with varied spacing ratios between the two tandem prisms, the active power (Pharn) was up to 1.95 times that of the single triangular prism (STP); 2) In general, the harnessed OCE capacity of the upstream triangular prism (UTP) was improved, while the energy harvesting of the downstream triangular prism (DTP) was suppressed by the interaction of the two prisms, 3) In the tests, electricity was generated at U = 0.516 m/s, and the active power, which consistently increased as flow velocity increased, reached Pharn = 32.24 W, with a corresponding efficiency of ηharn = 10.31%; and 4) The best energy conservation performance for harvesting the OCE occurred at L/D = 5, and the optimal load resistance was found at RL = 11 Ω

FECTS: A Facial Emotion Cognition and Training System for Chinese Children with Autism Spectrum Disorder

Traditional training methods such as card teaching, assistive technologies (e.g., augmented reality/virtual reality games and smartphone apps), DVDs, human-computer interactions, and human-robot interactions are widely applied in autistic rehabilitation training in recent years. In this article, we propose a novel framework for human-computer/robot interaction and introduce a preliminary intervention study for improving the emotion recognition of Chinese children with an autism spectrum disorder. The core of the framework is the Facial Emotion Cognition and Training System (FECTS, including six tasks to train children with ASD to match, infer, and imitate the facial expressions of happiness, sadness, fear, and anger) based on Simon Baron-Cohen's E-S (empathizing-systemizing) theory. Our system may be implemented on PCs, smartphones, mobile devices such as PADs, and robots. The training record (e.g., a tracked record of emotion imitation) of the Chinese autistic children interacting with the device implemented using our FECTS will be uploaded and stored in the database of a cloud-based evaluation system. Therapists and parents can access the analysis of the emotion learning progress of these autistic children using the cloud-based evaluation system. Deep-learning algorithms of facial expressions recognition and attention analysis will be deployed in the back end (e.g., devices such as a PC, a robotic system, or a cloud system) implementing our FECTS, which can perform real-time tracking of the imitation quality and attention of the autistic children during the expression imitation phase. In this preliminary clinical study, a total of 10 Chinese autistic children aged 3-8 are recruited, and each of them received a single 20-minute training session every day for four consecutive days. Our preliminary results validated the feasibility of the developed FECTS and the effectiveness of our algorithms based on Chinese children with an autism spectrum disorder. To verify that our FECTS can be further adapted to children from other countries, children with different cultural/sociological/linguistic contexts should be recruited in future studies

Wielding the sword: President Xi’s new anti-corruption campaign

A state achieves legitimacy through multiple sources, one of which is the effectiveness of its governance. Generations of scholars since Hobbes have identified the maintenance of peace and order as core functions of a legitimate state. In the modern world, economic prosperity, social stability and effective control of corruption often provide adequate compensation for a deficit of democracy. Corruption closely correlates with legitimacy. While a perceived pervasive, endemic corruption undermines the legitimacy of a regime, a successful anti-corruption campaign can allow a regime to recover from a crisis of legitimacy (Gilley 2009; Seligson and Booth 2009). This is the rationale behind the periodical campaigns against corruption that have been conducted by the Chinese Communist Party (‘Party’ or ‘CCP’) (Manion 2004; Wedeman 2012). Political leaders in China have found it expedient to use anti-corruption campaigns to remove their political foes, to rein in the bureaucracy and to restore public confidence in their ability to rule. Through anti-corruption campaigns, emerging political leaders consolidate their political power, secure loyalty from political factions and regional political forces, and enhance their legitimacy in the eyes of the general public. In an authoritarian state that experiences a high level of corruption, an anti-corruption campaign is a delicate political battle that addresses two significant concerns. The first concern is to orchestrate the campaign so that it is regime-reinforcing instead of regime-undermining. To remain credible, the regime must demonstrate its willingness and capacity to punish corrupt officials at the highest levels.preprin

Down-Regulation of AP-4 Inhibits Proliferation, Induces Cell Cycle Arrest and Promotes Apoptosis in Human Gastric Cancer Cells

BACKGROUND: AP-4 belongs to the basic helix-loop-helix leucine-zipper subgroup; it controls target gene expression, regulates growth, development and cell apoptosis and has been implicated in tumorigenesis. Our previous studies indicated that AP-4 was frequently overexpressed in gastric cancers and may be associated with the poor prognosis. The purpose of this study is to examine whether silencing of AP-4 can alter biological characteristics of gastric cancer cells. METHODS: Two specific siRNAs targeting AP-4 were designed, synthesized, and transfected into gastric cancer cell lines and human normal mucosa cells. AP-4 expression was measured with real-time quantitative PCR and Western blot. Cell proliferation and chemo-sensitivity were detected by CCK-8 assay. Cell cycle assay and apoptosis assay were performed by flow cytometer, and relative expression of cell cycle regulators were detected by real-time quantitative PCR and Western blot, expression of the factors involved in the apoptosis pathway were examined in mRNA and protein level. RESULTS: The expression of AP-4 was silenced by the siRNAs transfection and the effects of AP-4 knockdown lasted 24 to 96 hrs. The siRNA-mediated silencing of AP-4 suppressed the cellular proliferation, induced apoptosis and sensitized cancer cells to anticancer drugs. In addition, the expression level of p21, p53 and Caspase-9 were increased when AP-4 was knockdown, but the expression of cyclin D1, Bcl-2 and Bcl-x(L) was inhibited. It didn't induce cell cycle arrest when AP-4 was knockdown in p53 defect gastric cancer cell line Kato-III. CONCLUSIONS: These results illustrated that gene silencing of AP-4 can efficiently inhibited cell proliferation, triggered apoptosis and sensitized cancer cells to anticancer drugs in vitro, suggesting that AP-4 siRNAs mediated silencing has a potential value in the treatment of human gastric cancer

Hydrophobic coating- and surface active solvent-mediated self-assembly of charged gold and silver nanoparticles at water-air and water-oil interfaces

We report self-assembly of charge-stabilized gold and silver nanoparticles at water-air and water-oil interfaces, via manipulation of the interactions between the interfaces and the adsorbing nanoparticles. Nanoparticle adsorption from bulk colloids to an interface is an energy-favored, but finite sorption barrier-restrained (kinetics-controlled) process. Consequently, to successfully mediate self-assembly of nanoparticles, the finite sorption barrier should be decreased. That can be accomplished by manipulating its three controlling forces: the repulsive electrostatic force, the repulsive van der Waals force, and the attractive hydrophobic force between the interface and the adsorbing nanoparticles. It was found that hydrophobic coatings change nanoparticle hydrophobicity and greatly increase the attractive hydrophobic force. Surface active organic solvents ( methanol, ethanol, isopropanol, and acetone) decrease the attractive hydrophobic force to some extent. However, they decrease the repulsive electrostatic force to a larger extent, via a "charge dilution'' mechanism, due to their positive adsorption at the charged water-air and water-oil interfaces. Hydrophobic coatings and organic solvents consequently decrease the sorption barrier, facilitate nanoparticles overcoming the sorption barrier, and mediate the self-assembly of nanoparticles.Hunan Provincial Natural Science Foundation of China [06JJ3006]; Natural Science Foundation of China [20603008, 20703016, 20873037]; "985'' Foundation of the Ministry of Education of China