Assessments of landslide disasters are becoming increasingly urgent. The aim of this study is to investigate a convolutional neural network (CNN) framework for landslide susceptibility mapping (LSM) ...in Yanshan County, China. The two primary contributions of this study are summarized as follows. First, to the best of our knowledge, this report describes the first time that the CNN framework is used for LSM. Second, different data representation algorithms are developed to construct three novel CNN architectures. In this work, sixteen influencing factors associated with landslide occurrence were considered and historical landslide locations were randomly divided into training (70% of the total) and validation (30%) sets. Validation of these CNNs was performed using different commonly used measures in comparison to several of the most popular machine learning and deep learning methods. The experimental results demonstrated that the proportions of highly susceptible zones in all of the CNN landslide susceptibility maps are highly similar and lower than 30%, which indicates that these CNNs are more practical for landslide prevention and management than conventional methods. Furthermore, the proposed CNN framework achieved higher or comparable prediction accuracy. Specifically, the proposed CNNs were 3.94%–7.45% and 0.079–0.151 higher than those of the optimized support vector machine (SVM) in terms of overall accuracy (OA) and Matthews correlation coefficient (MCC), respectively.
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•Convolutional neural networks for landslide susceptibility mapping are carried out for the first time.•Three novel data representation algorithms are developed to fit the CNN architectures.•A comparative study on the proposed methods under the CNN framework is implemented in Yanshan County, China.•The proposed CNNs are superior to the state-of-the-art marching learning and deep learning methods.
Five types of superparamagnetic iron oxide (SPIO), i.e. Ferumoxides (Feridex(®) IV, Berlex Laboratories), Ferucarbotran (Resovist(®), Bayer Healthcare), Ferumoxtran-10 (AMI-227 or Code-7227, ...Combidex(®), AMAG Pharma; Sinerem(®), Guerbet), NC100150 (Clariscan(®), Nycomed,) and (VSOP C184, Ferropharm) have been designed and clinically tested as magnetic resonance contrast agents. However, until now Resovist(®) is current available in only a few countries. The other four agents have been stopped for further development or withdrawn from the market. Another SPIO agent Ferumoxytol (Feraheme(®)) is approved for the treatment of iron deficiency in adult chronic kidney disease patients. Ferumoxytol is comprised of iron oxide particles surrounded by a carbohydrate coat, and it is being explored as a potential imaging approach for evaluating lymph nodes and certain liver tumors.
This paper presents an analysis and control design of a doubly-fed induction generator (DFIG)-based wind generation system operating under unbalanced network conditions. A DFIG system model in the ...positive and negative synchronous reference frames is presented. Variations of stator active and reactive powers and generator torque are fully defined in the presence of negative sequence voltage and current. Alternative DFIG control targets during network unbalance, such as reducing stator current unbalance, torque, and power pulsations minimization, are identified. A rotor current control strategy based on positive and negative (dq) reference frames is used to provide precise control of the rotor positive and negative sequence currents. Simulation results using EMTDC/PSCAD are presented for a 2-MW DFIG wind generation system. It shows that conventional vector control of DFIG without considering network unbalance results in excessive oscillations on the stator active/reactive power, electromagnetic torque, and stator/rotor currents even with a small stator voltage unbalance. In contrast, with the proposed control strategy, enhanced system control and operation such as minimizing oscillations in either active power, or electromagnetic torque, or stator or rotor currents can be achieved
Abstract
We present the third open gravitational-wave catalog (3-OGC) of compact-binary coalescences, based on the analysis of the public LIGO and Virgo data from 2015 through 2019 (O1, O2, O3a). Our ...updated catalog includes a population of 57 observations, including 4 binary black hole mergers that had not been previously reported. This consists of 55 binary black hole mergers and the 2 binary neutron star mergers, GW170817 and GW190425. We find no additional significant binary neutron star or neutron star–black hole merger events. The most confident new detection is the binary black hole merger GW190925_232845, which was observed by the LIGO–Hanford and Virgo observatories with
astro
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0.99
;
its primary and secondary component masses are
20.2
−
2.5
+
3.9
M
⊙
and
15.6
−
2.6
+
2.1
M
⊙
, respectively. We estimate the parameters of all binary black hole events using an up-to-date waveform model that includes both subdominant harmonics and precession effects. To enable deep follow up as our understanding of the underlying populations evolves, we make available our comprehensive catalog of events, including the subthreshold population of candidates, and the posterior samples of our source parameter estimates.
This study investigates the dynamics of low-viscosity nanodroplets impacting surfaces with static contact angles from θ = 73° to 180° via molecular dynamics (MD) simulations. Two typical morphologies ...of impacting nanodroplets are observed at the maximum spreading state, a Hertz-ball-like in a low-Weber-number range and a thin-film-like in a high-Weber-number range. Only inertial and capillary forces dominate the impact for the former, whereas viscous force also becomes dominant for the latter. Regardless of morphologies at the maximum spreading state, the ratio of spreading time to contact time always remains constant on an ideal superhydrophobic surface with θ = 180°. With the help of different kinematic approximations of the spreading time and scaling laws of the contact time, scaling laws of the maximum spreading factor ${\beta _{max}}\sim W{e^{1/5}}$ in the low-Weber-number range (capillary regime) and ${\beta _{max}}\sim W{e^{2/3}}R{e^{ - 1/3}}$ (or ${\beta _{max}}\sim W{e^{1/2}}O{h^{1/3}}$) in the high-Weber-number range (cross-over regime) are obtained. Here, We, Re, and Oh are the Weber number, Reynolds number, and Ohnesorge number, respectively. Although the scaling laws are proposed only for the ideal superhydrophobic surface, they are tested valid for θ over 73° owing to the ignorable zero-velocity spreading effect. Furthermore, combining the two scaling laws leads to an impact number, $W{e^{3/10}}O{h^{1/3}} = 2.1$. This impact number can be used to determine whether viscous force is ignorable for impacting nanodroplets, thereby distinguishing the capillary regime from the cross-over regime.
Teacher resilience has a crucial role to play in teaching and teacher education all around the world. However, few practical attempts have been made to systematically improve and (re)build this ...characteristic in teachers. Against this backdrop, this article draws on a universal model to offer practical implications of building resilience in the teacher education of China which is largely oriented toward pedagogical and economic concerns rather than the socio-emotional aspects of teaching. More particularly, it explains the history of China's teacher education, the conceptualizations and significance of teacher resilience, and a systematic model to integrate resilience into teacher education. Finally, some practical implications and future directions are provided for avid scholars.
Pandemics have become more frequent and more complex during the twenty-first century. Posttraumatic stress disorder (PTSD) following pandemics is a significant public health concern. We sought to ...provide a reliable estimate of the worldwide prevalence of PTSD after large-scale pandemics as well as associated risk factors, by a systematic review and meta-analysis. We systematically searched the MedLine, Embase, PsycINFO, Web of Science, CNKI, WanFang, medRxiv, and bioRxiv databases to identify studies that were published from the inception up to August 23, 2020, and reported the prevalence of PTSD after pandemics including sudden acute respiratory syndrome (SARS), H1N1, Poliomyelitis, Ebola, Zika, Nipah, Middle Eastern respiratory syndrome coronavirus (MERS-CoV), H5N1, and coronavirus disease 2019 (COVID-19). A total of 88 studies were included in the analysis, with 77 having prevalence information and 70 having risk factors information. The overall pooled prevalence of post-pandemic PTSD across all populations was 22.6% (95% confidence interval (CI): 19.9-25.4%, I
: 99.7%). Healthcare workers had the highest prevalence of PTSD (26.9%; 95% CI: 20.3-33.6%), followed by infected cases (23.8%: 16.6-31.0%), and the general public (19.3%: 15.3-23.2%). However, the heterogeneity of study findings indicates that results should be interpreted cautiously. Risk factors including individual, family, and societal factors, pandemic-related factors, and specific factors in healthcare workers and patients for post-pandemic PTSD were summarized and discussed in this systematic review. Long-term monitoring and early interventions should be implemented to improve post-pandemic mental health and long-term recovery.
Alzheimer's disease is a neurodegenerative disease that causes memory loss, cognitive dysfunction and dementia. It is a multifactorial disease involving a wide range of pathological factors that have ...yet to be fully understood. As proposed by scientists and supported by a growing amount of evidence in recent years, the gut microbiota plays an important role in the pathogenesis of Alzheimer's disease via a constant bidirectional communication through the brain-gut-microbiota axis, which is a multifunctional network involving the nervous system and the peripheral circulatory system. This communication pathway facilitates the exchange of information and signals between the brain and the gut, such as microbe-derived metabolites and neurotransmitters, which allows gut microbes to influence the central nervous system. This review summarizes recent research findings on the pathological risk factors of Alzheimer's disease, the brain-gut-microbiota axis, the role of gut microbe-derived products in neurological disorders, and clinical/preclinical studies investigating the role of the gut microbiota in Alzheimer's disease. In addition, some suggestions for future research are proposed.
Cancer incidence is rising, and the efficacy of current available anticancer agents is limited by severe dose‐limiting toxicities and drug resistance problems. Nanoparticles are heralded as the next ...frontier in cancer treatment. Here, a pure physical method is used to efficiently fabricate very small silver particles even approaching the Ångstrom (Ång) dimension. Fructose is used as a dispersant and stabilizer to coat the Ång‐scale silver particles (AgÅPs). Functional and mechanistic studies demonstrate that fructose‐coated AgÅPs (F‐AgÅPs) can enter and accumulate in multiple cultured cancer cell lines to induce apoptotic death, whereas most normal cells are resistant to the efficacious dose of F‐AgÅPs; in vivo, intravenous administration of F‐AgÅPs potently inhibits the growth of pancreatic and lung cancer xenografts in nude mice, without inducing notable toxic effects on the healthy tissues. The results suggest the promising potential of F‐AgÅPs as a potent, safe, and broad‐spectrum agent for the cancer treatment.
Physical method‐fabricated fructose‐coated Ångstrom‐scale silver particles (F‐AgÅPs) have the ability to enter multiple cancer cells to induce apoptosis. Intravenous injection of F‐AgÅPs potently inhibits the growth of cancer xenograft models, without inducing notable toxic effects on healthy tissues. These results suggest that F‐AgÅPs have a great potential to be used as a potent, safe, and broad‐spectrum agent for cancer treatment.
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