The construction and operation of atmospheric nonthermal plasma jet, ANPJ, are presented in this work as well as the experimental investigations of its electrical parameters, the configuration of plasma jet column and...The construction and operation of atmospheric nonthermal plasma jet, ANPJ, are presented in this work as well as the experimental investigations of its electrical parameters, the configuration of plasma jet column and its temperature. The device is energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz) and the discharge takes place by using N2 gas with different flow rates from 3 to 25 L/min and input voltage of 6 kV. Diagnostic techniques such as voltage divider, Lissajous figure, image processing and thermometer are used. The electrical characteristics of discharge at different flow rates of N2 gas such as discharge voltage, current, mean power, power efficiency, and mean energy have been studied. The experimental results show that the maximum plasma jet length of 14 mm is detected at flow rate of 12 L/min. The results of plasma jet (heavy particles) temperature along the jet length show that jet plasma has approximately a room temperature at the jet column end. The results of zero flow rate effect on the ANPJ operation show damage in the Teflon insulator and a corrosion in the Aluminum electrodes.展开更多
Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault re...Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault regions. In this study, a new method for identifying the velocity pulses is proposed, based on different trends of two parameters: the short-time energy and the short-time zero crossing rate of a ground motion record. A new pulse indicator, the relative energy zero ratio(REZR), is defined to qualitatively identify pulse-like features. The threshold for pulse-like ground motions is derived and compared with two other identification methods through statistical analysis. The proposed procedure not only shows good accuracy and efficiency when identifying pulse-like ground motions but also exhibits good performance for classifying records with high-frequency noise and discontinuous pulses. The REZR method does not require a waveform formula to express and fit the potential velocity pulses;it is a purely signal-based classification method. Finally, the proposed procedure is used to evaluate the contribution of pulse-like motions to the total input energy of a seismic record, which dramatically increases the seismic damage potential.展开更多
Objective: To predict the daily incidence and fatality rates based on long short-term memory(LSTM) in 4 age groups of COVID-19 patients in Mazandaran Province, Iran.Methods: To predict the daily incidence and fatality...Objective: To predict the daily incidence and fatality rates based on long short-term memory(LSTM) in 4 age groups of COVID-19 patients in Mazandaran Province, Iran.Methods: To predict the daily incidence and fatality rates by age groups, this epidemiological study was conducted based on the LSTM model. All data of COVID-19 disease were collected daily for training the LSTM model from February 22, 2020 to April 10, 2021 in the Mazandaran University of Medical Sciences. We defined 4 age groups, i.e., patients under 29, between 30 and 49, between 50 and 59, and over 60 years old. Then, LSTM models were applied to predict the trend of daily incidence and fatality rates from 14 to 40 days in different age groups. The results of different methods were compared with each other.Results: This study evaluated 5 0826 patients and 5 109 deaths with COVID-19 daily in 20 cities of Mazandaran Province. Among the patients, 25 240 were females(49.7%), and 25 586 were males(50.3%). The predicted daily incidence rates on April 11, 2021 were 91.76, 155.84, 150.03, and 325.99 per 100 000 people, respectively;for the fourteenth day April 24, 2021, the predicted daily incidence rates were 35.91, 92.90, 83.74, and 225.68 in each group per 100 000 people. Furthermore, the predicted average daily incidence rates in 40 days for the 4 age groups were 34.25, 95.68, 76.43, and 210.80 per 100 000 people, and the daily fatality rates were 8.38, 4.18, 3.40, 22.53 per 100 000 people according to the established LSTM model. The findings demonstrated the daily incidence and fatality rates of 417.16 and 38.49 per 100 000 people for all age groups over the next 40 days. Conclusions: The results highlighted the proper performance of the LSTM model for predicting the daily incidence and fatality rates. It can clarify the path of spread or decline of the COVID-19 outbreak and the priority of vaccination in age groups.展开更多
This paper is concerned with the asymptotic behavior of solutions to the initial boundary problem of the two-dimensional density-dependent Boussinesq equations.It is shown that the solutions of the Boussinesq equation...This paper is concerned with the asymptotic behavior of solutions to the initial boundary problem of the two-dimensional density-dependent Boussinesq equations.It is shown that the solutions of the Boussinesq equations converge to those of zero thermal diffusivity Boussinesq equations as the thermal diffusivity tends to zero,and the convergence rate is established.In addition,we prove that the boundary-layer thickness is of the valueδ(k)=k^(α)with anyα∈(0,1/4)for a small diffusivity coefficient k>0,and we also find a function to describe the properties of the boundary layer.展开更多
AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori (H pylori)-infected active peptic ulcers. METHODS: We prospectively studied 115 consecutive patient...AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori (H pylori)-infected active peptic ulcers. METHODS: We prospectively studied 115 consecutive patients with H pylori-infected active peptic ulcers. H pylori infection was confirmed if any two of H pylori DNA, histology, and rapid urease test were positive. Patients were assigned to either an open-labeled 3-d course of oral amoxicillin 1 000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d., or 7-d course of oral amoxicillin 1 000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d. Subsequently, all patients received oral rabeprazole 20 mg once daily until the 8th wk. Three months after therapy, all patients were followed-up endoscopically for the peptic ulcer, H pylori DNA, histology, and rapid urease test. One year after therapy, H pylori infection was tested using the 13C-urea breath test. RESULTS: The ulcer healing rates 3 mo after therapy were 81.0% vs 75.4% for the 3-d and 7-d groups [intention-to-treat (ITT) analysis, P=0.47] respectively, and 90.4% vs 89.6% for the 3-d and 7-d groups [per-protocol (PP) analysis, P=0.89] respectively. The eradication rates 3 mo after therapy were 75.9% vs 73.7% for the 3-d and 7-d groups (ITT, P=0.79) respectively, and 84.6% vs 87.5% for the 3-d and 7-d groups (PP, P=0.68) respectively. One year after therapy, seventy-five patients returned to receive the 13C-urea breath test, and the eradication rates were 78.4% vs 81.6% in 3-d and 7-d groups (PP, P=0.73) respectively. CONCLUSION: Our study showed the eradication rates against H pylori infection 3 and 12 mo after triple therapy were not different between the 3-d and 7-d rabeprazole-based groups. Therefore, the 3-d rabeprazole-based triple therapy may be an alternative treatment for peptic ulcers with H pylori infection.展开更多
Different single-factor models are used to estimate the term structure of Hong Kong Inter-Bank Offered Rates （HIBOR）. These models use stochastic differential equations which effectively reflect market characteristi...Different single-factor models are used to estimate the term structure of Hong Kong Inter-Bank Offered Rates （HIBOR）. These models use stochastic differential equations which effectively reflect market characteristics of short- and long-term interest rates, such as capability of mean reversion and interest rate level fluctuation. For the period from 2005 to early 2007, the economy of Hong Kong had been relatively stable with pretty low volatilities in interest rate. However, starting from 2008 to beginning of 2012, the Hong Kong and the world economies had been steering from relatively stable to fluctuations, the 2008 financial tsunami initiated by the U,S. had been causing financial instability globally. With the U.S： government taking quantitative easing monetary policy, U.S. interest rates fluctuated and submerged rapidly. Volatility of HIBOR was extremely sensitive to fluctuation of U.S. interest rates, since Hong Kong dollar exchange rate has been pegged with U.S. dollar. In short, during the period of early 2008 to early 2012, volatility of short-term interest rate was extremely sensitive. Obviously, the term structure of interest rate for these two periods had made major shift, combining the two periods would lead to unfavorable econometric results.展开更多
Making use of the method of obtaining regional vertical strain rate from regional preciseleveling data and gaining dynamic pattern combining with deformation data on spanningfaults, the regional vertical strain dynami...Making use of the method of obtaining regional vertical strain rate from regional preciseleveling data and gaining dynamic pattern combining with deformation data on spanningfaults, the regional vertical strain dynamic evolution characteristics of several moderatelystrong earthquakes such as Lijiang (M_s 7.0) and Menyuan (M_s 6.4) earthquakes occurredin crustal deformation monitoring areas located in the western Yunnan and Qilianshan-Hexiregion. Based on the above-mentioned facts, by studying the time-space nonhomogeneity andstrain energy accumulation status, some criteria for judging the medium. and short-termstrong seismic risk regions according to the regional vertical strain rate dynamic informationare proposed.展开更多
INTRODUCTION Waste is a symbol of inefficiency in modern society and represents misallocated resources.This paper outlines an ongoing interdisciplinary research project entitled‘Integrated ETWW demand forecasting and...INTRODUCTION Waste is a symbol of inefficiency in modern society and represents misallocated resources.This paper outlines an ongoing interdisciplinary research project entitled‘Integrated ETWW demand forecasting and scenario planning for low-carbon precincts’and reports on first findings and a literature review.This large multi-stakeholder research project has been designed to develop a shared platform for integrated ETWW(energy,transport,waste,and water)planning in a low-carbon urban future,focusing on synergies and alternative approaches to urban planning.The aim of the project is to develop a holistic integrated software tool for demand forecasting and scenario evaluation for residential precincts covering the four domains(ETWW),using identified commonalities in data requirements and model formulation.The authors of this paper are overseeing the waste domain,while other researchers in the team have expertise in the remaining domains.展开更多
The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms...The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms only use part of the target location, speed, and other information for correlation.In this paper, the artificial neural network method is used to establish the corresponding intelligent track correlation model and method according to the characteristics of swarm targets.Precisely, a route correlation method based on convolutional neural networks (CNN) and long short-term memory (LSTM)Neural network is designed. In this model, the CNN is used to extract the formation characteristics of UAV swarm and the spatial position characteristics of single UAV track in the formation,while the LSTM is used to extract the time characteristics of UAV swarm. Experimental results show that compared with the traditional algorithms, the algorithm based on CNN-LSTM neural network can make full use of multiple feature information of the target, and has better robustness and accuracy for swarm targets.展开更多
文摘The construction and operation of atmospheric nonthermal plasma jet, ANPJ, are presented in this work as well as the experimental investigations of its electrical parameters, the configuration of plasma jet column and its temperature. The device is energized by a low-cost Neon power supply of (10 kV, 30 mA, and 20 kHz) and the discharge takes place by using N2 gas with different flow rates from 3 to 25 L/min and input voltage of 6 kV. Diagnostic techniques such as voltage divider, Lissajous figure, image processing and thermometer are used. The electrical characteristics of discharge at different flow rates of N2 gas such as discharge voltage, current, mean power, power efficiency, and mean energy have been studied. The experimental results show that the maximum plasma jet length of 14 mm is detected at flow rate of 12 L/min. The results of plasma jet (heavy particles) temperature along the jet length show that jet plasma has approximately a room temperature at the jet column end. The results of zero flow rate effect on the ANPJ operation show damage in the Teflon insulator and a corrosion in the Aluminum electrodes.
基金Supported by:National Natural Science Foundation of China under Grant Nos.51378341,51427901 and 51678407National Key Research and Development Program under Grant No.2016YFC0701108
文摘Pulse-like ground motions are capable of inflicting significant damage to structures. Efficient classification of pulse-like ground motion is of great importance when performing the seismic assessment in near-fault regions. In this study, a new method for identifying the velocity pulses is proposed, based on different trends of two parameters: the short-time energy and the short-time zero crossing rate of a ground motion record. A new pulse indicator, the relative energy zero ratio(REZR), is defined to qualitatively identify pulse-like features. The threshold for pulse-like ground motions is derived and compared with two other identification methods through statistical analysis. The proposed procedure not only shows good accuracy and efficiency when identifying pulse-like ground motions but also exhibits good performance for classifying records with high-frequency noise and discontinuous pulses. The REZR method does not require a waveform formula to express and fit the potential velocity pulses;it is a purely signal-based classification method. Finally, the proposed procedure is used to evaluate the contribution of pulse-like motions to the total input energy of a seismic record, which dramatically increases the seismic damage potential.
文摘Objective: To predict the daily incidence and fatality rates based on long short-term memory(LSTM) in 4 age groups of COVID-19 patients in Mazandaran Province, Iran.Methods: To predict the daily incidence and fatality rates by age groups, this epidemiological study was conducted based on the LSTM model. All data of COVID-19 disease were collected daily for training the LSTM model from February 22, 2020 to April 10, 2021 in the Mazandaran University of Medical Sciences. We defined 4 age groups, i.e., patients under 29, between 30 and 49, between 50 and 59, and over 60 years old. Then, LSTM models were applied to predict the trend of daily incidence and fatality rates from 14 to 40 days in different age groups. The results of different methods were compared with each other.Results: This study evaluated 5 0826 patients and 5 109 deaths with COVID-19 daily in 20 cities of Mazandaran Province. Among the patients, 25 240 were females(49.7%), and 25 586 were males(50.3%). The predicted daily incidence rates on April 11, 2021 were 91.76, 155.84, 150.03, and 325.99 per 100 000 people, respectively;for the fourteenth day April 24, 2021, the predicted daily incidence rates were 35.91, 92.90, 83.74, and 225.68 in each group per 100 000 people. Furthermore, the predicted average daily incidence rates in 40 days for the 4 age groups were 34.25, 95.68, 76.43, and 210.80 per 100 000 people, and the daily fatality rates were 8.38, 4.18, 3.40, 22.53 per 100 000 people according to the established LSTM model. The findings demonstrated the daily incidence and fatality rates of 417.16 and 38.49 per 100 000 people for all age groups over the next 40 days. Conclusions: The results highlighted the proper performance of the LSTM model for predicting the daily incidence and fatality rates. It can clarify the path of spread or decline of the COVID-19 outbreak and the priority of vaccination in age groups.
基金the National Natural Science Foundation of China(12061037,11971209)the Natural Science Foundation of Jiangxi Province(20212BAB201016)National Natural Science Foundation of China(11861038)。
文摘This paper is concerned with the asymptotic behavior of solutions to the initial boundary problem of the two-dimensional density-dependent Boussinesq equations.It is shown that the solutions of the Boussinesq equations converge to those of zero thermal diffusivity Boussinesq equations as the thermal diffusivity tends to zero,and the convergence rate is established.In addition,we prove that the boundary-layer thickness is of the valueδ(k)=k^(α)with anyα∈(0,1/4)for a small diffusivity coefficient k>0,and we also find a function to describe the properties of the boundary layer.
基金Supported by the grant from China Medical University Hospital,Taichung, Taiwan, China
文摘AIM: To investigate the long-term role of a 3-d rabeprazole-based triple therapy in patients with Helicobacter pylori (H pylori)-infected active peptic ulcers. METHODS: We prospectively studied 115 consecutive patients with H pylori-infected active peptic ulcers. H pylori infection was confirmed if any two of H pylori DNA, histology, and rapid urease test were positive. Patients were assigned to either an open-labeled 3-d course of oral amoxicillin 1 000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d., or 7-d course of oral amoxicillin 1 000 mg b.i.d., clarithromycin 500 mg b.i.d., and rabeprazole 20 mg b.i.d. Subsequently, all patients received oral rabeprazole 20 mg once daily until the 8th wk. Three months after therapy, all patients were followed-up endoscopically for the peptic ulcer, H pylori DNA, histology, and rapid urease test. One year after therapy, H pylori infection was tested using the 13C-urea breath test. RESULTS: The ulcer healing rates 3 mo after therapy were 81.0% vs 75.4% for the 3-d and 7-d groups [intention-to-treat (ITT) analysis, P=0.47] respectively, and 90.4% vs 89.6% for the 3-d and 7-d groups [per-protocol (PP) analysis, P=0.89] respectively. The eradication rates 3 mo after therapy were 75.9% vs 73.7% for the 3-d and 7-d groups (ITT, P=0.79) respectively, and 84.6% vs 87.5% for the 3-d and 7-d groups (PP, P=0.68) respectively. One year after therapy, seventy-five patients returned to receive the 13C-urea breath test, and the eradication rates were 78.4% vs 81.6% in 3-d and 7-d groups (PP, P=0.73) respectively. CONCLUSION: Our study showed the eradication rates against H pylori infection 3 and 12 mo after triple therapy were not different between the 3-d and 7-d rabeprazole-based groups. Therefore, the 3-d rabeprazole-based triple therapy may be an alternative treatment for peptic ulcers with H pylori infection.
文摘Different single-factor models are used to estimate the term structure of Hong Kong Inter-Bank Offered Rates （HIBOR）. These models use stochastic differential equations which effectively reflect market characteristics of short- and long-term interest rates, such as capability of mean reversion and interest rate level fluctuation. For the period from 2005 to early 2007, the economy of Hong Kong had been relatively stable with pretty low volatilities in interest rate. However, starting from 2008 to beginning of 2012, the Hong Kong and the world economies had been steering from relatively stable to fluctuations, the 2008 financial tsunami initiated by the U,S. had been causing financial instability globally. With the U.S： government taking quantitative easing monetary policy, U.S. interest rates fluctuated and submerged rapidly. Volatility of HIBOR was extremely sensitive to fluctuation of U.S. interest rates, since Hong Kong dollar exchange rate has been pegged with U.S. dollar. In short, during the period of early 2008 to early 2012, volatility of short-term interest rate was extremely sensitive. Obviously, the term structure of interest rate for these two periods had made major shift, combining the two periods would lead to unfavorable econometric results.
基金This research was sponsored by the National Key Basic Research Project (G1998040703) and China Seismological Burear (95-04-04-01-01).
文摘Making use of the method of obtaining regional vertical strain rate from regional preciseleveling data and gaining dynamic pattern combining with deformation data on spanningfaults, the regional vertical strain dynamic evolution characteristics of several moderatelystrong earthquakes such as Lijiang (M_s 7.0) and Menyuan (M_s 6.4) earthquakes occurredin crustal deformation monitoring areas located in the western Yunnan and Qilianshan-Hexiregion. Based on the above-mentioned facts, by studying the time-space nonhomogeneity andstrain energy accumulation status, some criteria for judging the medium. and short-termstrong seismic risk regions according to the regional vertical strain rate dynamic informationare proposed.
基金supported by the Zero Waste Research Centre for Sustainable Design and Behaviour(sd+b)and the China–Australia Centre for Sustainable Urban Development(CAC_SUD)at the University of South Australia(UniSA).
文摘INTRODUCTION Waste is a symbol of inefficiency in modern society and represents misallocated resources.This paper outlines an ongoing interdisciplinary research project entitled‘Integrated ETWW demand forecasting and scenario planning for low-carbon precincts’and reports on first findings and a literature review.This large multi-stakeholder research project has been designed to develop a shared platform for integrated ETWW(energy,transport,waste,and water)planning in a low-carbon urban future,focusing on synergies and alternative approaches to urban planning.The aim of the project is to develop a holistic integrated software tool for demand forecasting and scenario evaluation for residential precincts covering the four domains(ETWW),using identified commonalities in data requirements and model formulation.The authors of this paper are overseeing the waste domain,while other researchers in the team have expertise in the remaining domains.
文摘The rapid development of unmanned aerial vehicle(UAV) swarm, a new type of aerial threat target, has brought great pressure to the air defense early warning system. At present, most of the track correlation algorithms only use part of the target location, speed, and other information for correlation.In this paper, the artificial neural network method is used to establish the corresponding intelligent track correlation model and method according to the characteristics of swarm targets.Precisely, a route correlation method based on convolutional neural networks (CNN) and long short-term memory (LSTM)Neural network is designed. In this model, the CNN is used to extract the formation characteristics of UAV swarm and the spatial position characteristics of single UAV track in the formation,while the LSTM is used to extract the time characteristics of UAV swarm. Experimental results show that compared with the traditional algorithms, the algorithm based on CNN-LSTM neural network can make full use of multiple feature information of the target, and has better robustness and accuracy for swarm targets.
