Many symmetric and asymmetric encryption algorithms have been developed in cloud computing to transmit data in a secure form.Cloud cryptography is a data encryption mechanism that consists of different steps and preve...Many symmetric and asymmetric encryption algorithms have been developed in cloud computing to transmit data in a secure form.Cloud cryptography is a data encryption mechanism that consists of different steps and prevents the attacker from misusing the data.This paper has developed an efficient algorithm to protect the data from invaders and secure the data from misuse.If this algorithm is applied to the cloud network,the attacker will not be able to access the data.To encrypt the data,the values of the bytes have been obtained by converting the plain text to ASCII.A key has been generated using the Non-Deterministic Bit Generator(NRBG)mechanism,and the key is XNORed with plain text bits,and then Bit toggling has been implemented.After that,an efficient matrix cipher encryption algorithm has been developed,and this algorithm has been applied to this text.The capability of this algorithm is that with its help,a key has been obtained from the plain text,and only by using this key can the data be decrypted in the first steps.A plain text key will never be used for another plain text.The data has been secured by implementing different mechanisms in both stages,and after that,a ciphertext has been obtained.At the end of the article,the latest technique will be compared with different techniques.There will be a discussion on how the present technique is better than all the other techniques;then,the conclusion will be drawn based on comparative analysis.展开更多
Internet Protocol version 6(IPv6)is the latest version of IP that goal to host 3.4×10^(38)unique IP addresses of devices in the network.IPv6 has introduced new features like Neighbour Discovery Protocol(NDP)and A...Internet Protocol version 6(IPv6)is the latest version of IP that goal to host 3.4×10^(38)unique IP addresses of devices in the network.IPv6 has introduced new features like Neighbour Discovery Protocol(NDP)and Address Auto-configuration Scheme.IPv6 needed several protocols like the Address Auto-configuration Scheme and Internet Control Message Protocol(ICMPv6).IPv6 is vulnerable to numerous attacks like Denial of Service(DoS)and Distributed Denial of Service(DDoS)which is one of the most dangerous attacks executed through ICMPv6 messages that impose security and financial implications.Therefore,an Intrusion Detection System(IDS)is a monitoring system of the security of a network that detects suspicious activities and deals with amassive amount of data comprised of repetitive and inappropriate features which affect the detection rate.A feature selection(FS)technique helps to reduce the computation time and complexity by selecting the optimum subset of features.This paper proposes a method for detecting DDoS flooding attacks(FA)based on ICMPv6 messages using a Binary Flower PollinationAlgorithm(BFPA-FA).The proposed method(BFPA-FA)employs FS technology with a support vector machine(SVM)to identify the most relevant,influential features.Moreover,The ICMPv6-DDoS dataset was used to demonstrate the effectiveness of the proposed method through different attack scenarios.The results show that the proposed method BFPAFA achieved the best accuracy rate(97.96%)for the ICMPv6 DDoS detection with a reduced number of features(9)to half the total(19)features.The proven proposed method BFPA-FAis effective in the ICMPv6 DDoS attacks via IDS.展开更多
The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental p...The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental pathogens and potentially overreactive immune cells from entering the periphery.When the double-edged neuroinflammatory response is overloaded,it no longer has the protective function of promoting neuroregeneration.Notably,microbiota and its derivatives may emerge as pathogen-associated molecular patterns of brain pathology,causing microbiome–gut–brain axis dysregulation from the bottom-up.When dysbiosis of the gastrointestinal flora leads to subsequent alterations in BBB permeability,peripheral immune cells are recruited to the brain.This results in amplification of neuroinflammatory circuits in the brain,which eventually leads to specific neurological disorders.Aggressive treatment strategies for gastrointestinal disorders may protect against specific immune responses to gastrointestinal disorders,which can lead to potential protective effects in the CNS.Accordingly,this study investigated the mutual effects of microbiota and the gut–brain axis,which may provide targeting strategies for future disease treatment.展开更多
This study aimed to examine the association between the use of H1-antihistamines(AHs)and head and neck cancer(HNC)risk in patients with type 2 diabetes mellitus(T2DM).Data from the National Health Insurance Research D...This study aimed to examine the association between the use of H1-antihistamines(AHs)and head and neck cancer(HNC)risk in patients with type 2 diabetes mellitus(T2DM).Data from the National Health Insurance Research Database of Taiwan were analyzed for the period from 2008 to 2018.A propensity-score-matched cohort of 54,384 patients each in the AH user and nonuser groups was created and analyzed using Kaplan-Meier method and Cox proportional hazards regression.The results showed that the risk of HNC was significantly lower in AH users(adjusted hazard ratio:0.55,95%CI:0.48 to 0.64)and the incidence rate was also lower(5.16 vs.8.10 per 100,000 person-years).The lower HNC incidence rate in AH users(95%CI:0.63;0.55 to 0.73)suggests that AH use may reduce the risk of HNC in T2DM patients.展开更多
Food safety has received a great deal of attention in both developed and developing countries in recent years. In China, the numerous food scandals and scares that have struck over the past decade have spurred signifi...Food safety has received a great deal of attention in both developed and developing countries in recent years. In China, the numerous food scandals and scares that have struck over the past decade have spurred significant food safety regulatory reform, which has been increasingly oriented towards the public-private partnership model adopted by the Europe Union's (EU) food safety regulatory system. This paper analyzes the development of both the EU's and China's food safety regu- latory systems, identifies the current challenges for China and additionally considers the role of public-private partnership. The success of co-regulation in the food regulatory system would bring significant benefits and opportunities for China. Finally, this paper recommends additional measures like training and grants to improve the private's sector effectiveness in co-regulating China's food safety issues.展开更多
In reality,the flipped classroom has gained popularity as a modern way of structuring teaching,where lectures move from in-class procedures to digitally-based assignments,freeing up the debate,and practice exercises c...In reality,the flipped classroom has gained popularity as a modern way of structuring teaching,where lectures move from in-class procedures to digitally-based assignments,freeing up the debate,and practice exercises class time.Therefore,it is essential to implement and analyze a way of teaching that will improve student performance.The paper aims to develop a model of the method of teaching science in Iraqi schools,and to assess whether teaching flipped classroom affects the achievement,motivation,and creative thinking of students by using the methodology of Multi-Criteria Decision Making(MCDM)in the Analytic Hierarchy Process(AHP).The AHP approach includes several steps,including setting assessment criteria and their weights,and by assessing the methodology of the flipped classroom as compared to the conventional cognitive learning process.An experiment was carried out in Iraqi secondary schools to examine the attitude of the students towards the subject of Chemistry.The findings have indicated that the students and teachers favored flipped classroom learning more than conventional cognitive learning.The study took the following parameters compared to the traditional approach:teaching techniques,learning flexibility,teaching aids effectiveness,student participation and working environment.This paper indicates that the teachers in Iraqi schools will be able to improve and do more preparation to shift towards flipped learning in the classroom.展开更多
Central bank digital currencies(CBDCs),which are legal tenders in digital form,are expected to reduce currency issuance and circulation costs and broaden the scope of monetary policy.In addition,these currencies may a...Central bank digital currencies(CBDCs),which are legal tenders in digital form,are expected to reduce currency issuance and circulation costs and broaden the scope of monetary policy.In addition,these currencies may also reduce consumers’need for conventional demand deposits,which,in turn,increases banks’loan provision costs because deposits require higher rates of return.We use a microeconomic banking model to investigate the effects of introducing an economy-wide,account-type CBDC on a bank’s loan supply and its failure risk.Given that a CBDC is expected to lower the cost of liquidity circulation and become a strong substitute for demand deposits,both the loan supply and the bank failure risk increase.These increases are countered by subsequent increases in the rates of return on term deposits and loans,which,in turn,reduce the loan supply and thus bank failure risk.These offsetting forces lead to no significant change in banking,as long as the rate of return on loans is below a certain threshold.However,once the rate is above the threshold,bank failure risk increases,thereby undermining banking stability.The problem is more pronounced when the degree of pass-through of funding costs to the loan rate is high and the profitability of a successful project is low.Our results imply that central banks wishing to introduce an economy-wide,account-type CBDC should first monitor yields on bank loans and consider policy measures that induce banks to maintain adequate liquidity reserve levels.展开更多
This study investigates the dynamic connectedness between stock indices and the effect of economic policy uncertainty(EPU)in eight countries where COVID-19 was most widespread(China,Italy,France,Germany,Spain,Russia,t...This study investigates the dynamic connectedness between stock indices and the effect of economic policy uncertainty(EPU)in eight countries where COVID-19 was most widespread(China,Italy,France,Germany,Spain,Russia,the US,and the UK)by implementing the time-varying VAR(TVP-VAR)model for daily data over the period spanning from 01/01/2015 to 05/18/2020.Results showed that stock markets were highly connected during the entire period,but the dynamic spillovers reached unprecedented heights during the COVID-19 pandemic in the first quarter of 2020.Moreover,we found that the European stock markets(except Italy)transmitted more spillovers to all other stock markets than they received,primarily during the COVID-19 outbreak.Further analysis using a nonlinear framework showed that the dynamic connectedness was more pronounced for negative than for positive returns.Also,findings showed that the direction of the EPU effect on net connectedness changed during the pandemic onset,indicating that information spillovers from a given market may signal either good or bad news for other markets,depending on the prevailing economic situation.These results have important implications for individual investors,portfolio managers,policymakers,investment banks,and central banks.展开更多
The nanoparticle transportation and Brownian diffusion in planar jet flow is simulated via large eddy simulation in this work. To thorough compare the Brownian diffusion with different particle size, we computed three...The nanoparticle transportation and Brownian diffusion in planar jet flow is simulated via large eddy simulation in this work. To thorough compare the Brownian diffusion with different particle size, we computed three particle diameter dp = 1 nm, 10 nm and 50 nm in one simulation process simultaneously. The numerical results showed that at the flow de- veloping stage, the particle mass concentration pattern develops as the flow vorticity develops. The distribution is nearly uniform at the lower reaches of the nozzle exit. When the jet flow is developing on, vortexes always carry the particle from upstream to downstream, from the central axis region to the outer mixing layer of jet. At the front of the jet flow, particles distribute more homogeneous for they have more residence time to diffuse from higher concentration region to the lower concentration region. The time averaged particle concentration distribution patterns are similar to Gaussian distribution form. The maximum concentration contributed by diffusion is present at the mixing layer near the nozzle exit. The farther away from the nozzle exit in the cross-stream direction, the smaller the concentration is. The maximum concentration contributed by diffusion is several orders smaller than that contributed by flow convection.展开更多
Particle coagulation by Brownian motion is an important but difficult research topic.When particle volume concentration is larger than 0.1%,the classic SMOLUCHOWSKI equation is not applicative anymore.The high concent...Particle coagulation by Brownian motion is an important but difficult research topic.When particle volume concentration is larger than 0.1%,the classic SMOLUCHOWSKI equation is not applicative anymore.The high concentration coagulation,with HEINE's correction,source terms for the Taylor-series expansion method of moments(TEMOM) are firstly driven in this paper.Ultra-fine particle(d0?100 mm) with initial volume fraction f?1% coagulation in a planar jet turbulence flow is simulated via the large eddy simulation(LES).The instantaneous and time-averaged particle distributions and the high concentration enhancement are given out.The particle number concentration distribution results show that the coagulation is more intense comparing to dilute case in previous research,especially near the nozzle exit.After jet flow is fully developed,the effect is much more obvious at the region between vortexes.The time-averaged γ(the high concentration enhance factor) distributes sharply and symmetrically about the jet centerline at the upstream,but becomes broad and flat at downstream where the cross-stream averaged γ fluctuates drastically.As a new attempt,this paper shows Brownian coagulation with high concentration also can be calculated via TEMOM appropriately,and the coagulation at the region between vortexes is about 1.38 times intensive of the dilute result calculated by the classic Smoluchowski theory.展开更多
Online Food Delivery Platforms(OFDPs)has witnessed phenomenal growth in the past few years,especially this year due to the COVID-19 pandemic.This Pandemic has forced many governments across the world to give momentum ...Online Food Delivery Platforms(OFDPs)has witnessed phenomenal growth in the past few years,especially this year due to the COVID-19 pandemic.This Pandemic has forced many governments across the world to give momentum to OFD services and make their presence among the customers.The Presence of several multinational and national companies in this sector has enhanced the competition and companies are trying to adapt various marketing strategies and exploring the brand experience(BEX)dimension that helps in enhancing the brand equity(BE)of OFDPs.BEXs are critical for building brand loyalty(BL)and making companies profitable.Customers can experience different kinds of brand experiences through feeling,emotions,affection,behavior,and intellect.The present research work is taken up to analyze the factors affecting BEX and its impact on BL and BE of the OFDPs and analyze the mediating role of BL in the relationship between BEX and BE of the OFDPs in the Indian context.A survey of 457 Indian customers was carried out.A questionnaire was used for data collection and a mediation study was used to test hypothesized relationships.Our computational analysis reveals that BEX influences the BL and BE of OFDPs.The study further indicates that BL mediates the relationship between BEX and BE of OFDPs.The effective marketing and relationship management practices will help company to enhance BEX that will enable in enhancing BL and raising BE of their product.It therefore provides a more thorough analysis of BEX constructs and their consequences than previous research.Some of the managerial implication,limitations,and scope of future research are also presented in the study.展开更多
Objective: based on the analysis to the elements affecting the results of China's national team in the 2010 mountain outdoor sports adventure challenge race in Abu Dhabi, some theoretical and practical basis on wh...Objective: based on the analysis to the elements affecting the results of China's national team in the 2010 mountain outdoor sports adventure challenge race in Abu Dhabi, some theoretical and practical basis on which suggestions are provided on further promoting China's mountain outdoor sports results and the competitive level are given.Subjects: athletic performance of the top six teams and China's national team in 2010 mountain outdoor sports and athletic performance;Methods: using expert interviews, reference and data, mathematical statistics, analyze the athletic performance of the top six teams and China's national team in 2010 mountain outdoor sports and athletic performance on foot and bicycle projects on class projects with the world's top mountain outdoor big gap between sports teams;Result: there are big gaps between China's mountain outdoor sports teams and foreign teams on projects like footing and bicycling;Conclusion: Although in recent years, our mountain outdoor sports performance has been greatly improved, but the large gap do exist on foot and bicycle projects. so these projects need strengthening .展开更多
Since the State Council issued The Decision of the State Council on Accelerating the Cultivation and Development of Strategic Emerging Industries and the construction of the Central Plains Economic Zone was regarded a...Since the State Council issued The Decision of the State Council on Accelerating the Cultivation and Development of Strategic Emerging Industries and the construction of the Central Plains Economic Zone was regarded as a national strategy, accelerating the cultivation and development of strategic emerging industries has been placed to a prominent position to promote the upgrading of the strategic adjustment of the economic structure and industrial transformation. In this paper, three primary indexes and eight secondary indexes are selected to construct the growth evaluation index system in Henan's strategic emerging industries; Based on Factor Analysis, the enterprise growth of strategic emerging industries in Henan Province was evaluated comprehensively. The conclusion provides a reference for the overall development of strategic emerging industries in Henan.展开更多
Endovascular intervention,such as percu-taneous transluminal angioplasty(PTA),improves claudication and saves limbs of patients with severe lower extremity arterial dis-ease(LEAD).[1]A previous study showed that the m...Endovascular intervention,such as percu-taneous transluminal angioplasty(PTA),improves claudication and saves limbs of patients with severe lower extremity arterial dis-ease(LEAD).[1]A previous study showed that the mortality among octogenarians was as high as 29%regardless of the type of intervention and that re-vascularization was associated with high peripro-cedural mortality.[2]A previous study had already shown that reconstructive surgery for elderly indi-viduals over 80 years old resulted in a significantly higher mortality rate than that for patients between 70 and 80 years old,whereas endovascular inter-vention and primarily conservative treatment had comparable prognoses.[3]Consistently,another study showed that the risks of both overall and am-putation-free survival were significantly lower with endovascular treatment than with bypass surgery in patients with critical limb ischemia.[4]A systematic review and meta-analysis of 27 studies(15 cohort and 12 randomized controlled trials)with 1642 pa-tients suggests that conservative treatment may be considered for nonreconstructable patients with critical limb ischemia;[5]however,because a high risk of bias and serious inconsistencies were found in the included studies,the meta-analysis provided low-quality evidence.In contrast,a small cohort study with 49 patients suggests that amputation im-proved quality of life and health status in fragile elderly individuals.展开更多
In order to foster an innovative spirit and ability of high-quality talent, much student research training program in domestic universities will incorporate innovative talent training plan. However, the evaluation mec...In order to foster an innovative spirit and ability of high-quality talent, much student research training program in domestic universities will incorporate innovative talent training plan. However, the evaluation mechanism existing research training program is still not perfect for college students, this article has been carrying out a more in-depth discussion and proposes research training program evaluation system for university students.展开更多
background The risk of symptomatic intracranial haemorrhage(sICH)after thrombolysis is low but severe.Lower dose of alteplase may reduce the risk of sICH.We aim to identify subsets of patients who could benefit from l...background The risk of symptomatic intracranial haemorrhage(sICH)after thrombolysis is low but severe.Lower dose of alteplase may reduce the risk of sICH.We aim to identify subsets of patients who could benefit from lower dose of alteplase compared with standard dose.Methods Data from two observational registries were pooled together.A total of 3479 patients who had acute ischaemic stroke were entered into the interaction tree model.The response variable was the rate of sICH per the definition of the National Institute of Neurological Disorders and Stroke Study.Clinical improvement was measured by the National Institutes of Health Stroke Scale(NIHSS)and defined as NIHSS 0 or 1 or an improvement of more than 4 points(within 7 days or at discharge).Rare event logistic regression was performed to analyse the OR of safety outcome.results To optimise the interaction effect between tissue plasminogen activator(tPA)dosage(standard/lower)and patient subgroups,three subgroups based on the severity of stroke were identified:(1)NIHSS≤4,(2)NIHSS between 5 and 14,and(3)NIHSS≥15.The estimated difference of OR of having sICH was 2.71(95%CI 0.80 to 7.69,p=0.10)for mild,0.13(95%CI 0.02 to 0.68,p=0.01)for moderate,and 0.65(95%CI 0.19 to 2.55,p=0.52)for severe,respectively.In addition,patients who had moderate stroke treated with lower dose had comparable efficacy outcome(OR 1.23,95%CI 0.71 to 2.13,p=0.45).Conclusion Our analysis demonstrated that in patients who had moderate stroke,lower doses of alteplase are associated with significant sICH reduction and non-inferior performance in efficacy,compared with those in the standard dose group.展开更多
文摘Many symmetric and asymmetric encryption algorithms have been developed in cloud computing to transmit data in a secure form.Cloud cryptography is a data encryption mechanism that consists of different steps and prevents the attacker from misusing the data.This paper has developed an efficient algorithm to protect the data from invaders and secure the data from misuse.If this algorithm is applied to the cloud network,the attacker will not be able to access the data.To encrypt the data,the values of the bytes have been obtained by converting the plain text to ASCII.A key has been generated using the Non-Deterministic Bit Generator(NRBG)mechanism,and the key is XNORed with plain text bits,and then Bit toggling has been implemented.After that,an efficient matrix cipher encryption algorithm has been developed,and this algorithm has been applied to this text.The capability of this algorithm is that with its help,a key has been obtained from the plain text,and only by using this key can the data be decrypted in the first steps.A plain text key will never be used for another plain text.The data has been secured by implementing different mechanisms in both stages,and after that,a ciphertext has been obtained.At the end of the article,the latest technique will be compared with different techniques.There will be a discussion on how the present technique is better than all the other techniques;then,the conclusion will be drawn based on comparative analysis.
文摘Internet Protocol version 6(IPv6)is the latest version of IP that goal to host 3.4×10^(38)unique IP addresses of devices in the network.IPv6 has introduced new features like Neighbour Discovery Protocol(NDP)and Address Auto-configuration Scheme.IPv6 needed several protocols like the Address Auto-configuration Scheme and Internet Control Message Protocol(ICMPv6).IPv6 is vulnerable to numerous attacks like Denial of Service(DoS)and Distributed Denial of Service(DDoS)which is one of the most dangerous attacks executed through ICMPv6 messages that impose security and financial implications.Therefore,an Intrusion Detection System(IDS)is a monitoring system of the security of a network that detects suspicious activities and deals with amassive amount of data comprised of repetitive and inappropriate features which affect the detection rate.A feature selection(FS)technique helps to reduce the computation time and complexity by selecting the optimum subset of features.This paper proposes a method for detecting DDoS flooding attacks(FA)based on ICMPv6 messages using a Binary Flower PollinationAlgorithm(BFPA-FA).The proposed method(BFPA-FA)employs FS technology with a support vector machine(SVM)to identify the most relevant,influential features.Moreover,The ICMPv6-DDoS dataset was used to demonstrate the effectiveness of the proposed method through different attack scenarios.The results show that the proposed method BFPAFA achieved the best accuracy rate(97.96%)for the ICMPv6 DDoS detection with a reduced number of features(9)to half the total(19)features.The proven proposed method BFPA-FAis effective in the ICMPv6 DDoS attacks via IDS.
文摘The central nervous system(CNS)is a reservoir of immune privilege.Specialized immune glial cells are responsible for maintenance and defense against foreign invaders.The blood–brain barrier(BBB)prevents detrimental pathogens and potentially overreactive immune cells from entering the periphery.When the double-edged neuroinflammatory response is overloaded,it no longer has the protective function of promoting neuroregeneration.Notably,microbiota and its derivatives may emerge as pathogen-associated molecular patterns of brain pathology,causing microbiome–gut–brain axis dysregulation from the bottom-up.When dysbiosis of the gastrointestinal flora leads to subsequent alterations in BBB permeability,peripheral immune cells are recruited to the brain.This results in amplification of neuroinflammatory circuits in the brain,which eventually leads to specific neurological disorders.Aggressive treatment strategies for gastrointestinal disorders may protect against specific immune responses to gastrointestinal disorders,which can lead to potential protective effects in the CNS.Accordingly,this study investigated the mutual effects of microbiota and the gut–brain axis,which may provide targeting strategies for future disease treatment.
基金Lo-Hsu Medical Foundation,LotungPoh-Ai Hospital,supports Szu-Yuan Wu’s work(Funding Numbers:10908,10909,11001,11002,11003,11006,and 11013).
文摘This study aimed to examine the association between the use of H1-antihistamines(AHs)and head and neck cancer(HNC)risk in patients with type 2 diabetes mellitus(T2DM).Data from the National Health Insurance Research Database of Taiwan were analyzed for the period from 2008 to 2018.A propensity-score-matched cohort of 54,384 patients each in the AH user and nonuser groups was created and analyzed using Kaplan-Meier method and Cox proportional hazards regression.The results showed that the risk of HNC was significantly lower in AH users(adjusted hazard ratio:0.55,95%CI:0.48 to 0.64)and the incidence rate was also lower(5.16 vs.8.10 per 100,000 person-years).The lower HNC incidence rate in AH users(95%CI:0.63;0.55 to 0.73)suggests that AH use may reduce the risk of HNC in T2DM patients.
基金provided by the CGIAR Research Program on Policies, Institutions, and Marketsby the National Natural Science Foundation of China (NSFC) Program on "Food Value Chain Upgrading for Food Safety in Transforming Food Markets" (71273269)
文摘Food safety has received a great deal of attention in both developed and developing countries in recent years. In China, the numerous food scandals and scares that have struck over the past decade have spurred significant food safety regulatory reform, which has been increasingly oriented towards the public-private partnership model adopted by the Europe Union's (EU) food safety regulatory system. This paper analyzes the development of both the EU's and China's food safety regu- latory systems, identifies the current challenges for China and additionally considers the role of public-private partnership. The success of co-regulation in the food regulatory system would bring significant benefits and opportunities for China. Finally, this paper recommends additional measures like training and grants to improve the private's sector effectiveness in co-regulating China's food safety issues.
文摘In reality,the flipped classroom has gained popularity as a modern way of structuring teaching,where lectures move from in-class procedures to digitally-based assignments,freeing up the debate,and practice exercises class time.Therefore,it is essential to implement and analyze a way of teaching that will improve student performance.The paper aims to develop a model of the method of teaching science in Iraqi schools,and to assess whether teaching flipped classroom affects the achievement,motivation,and creative thinking of students by using the methodology of Multi-Criteria Decision Making(MCDM)in the Analytic Hierarchy Process(AHP).The AHP approach includes several steps,including setting assessment criteria and their weights,and by assessing the methodology of the flipped classroom as compared to the conventional cognitive learning process.An experiment was carried out in Iraqi secondary schools to examine the attitude of the students towards the subject of Chemistry.The findings have indicated that the students and teachers favored flipped classroom learning more than conventional cognitive learning.The study took the following parameters compared to the traditional approach:teaching techniques,learning flexibility,teaching aids effectiveness,student participation and working environment.This paper indicates that the teachers in Iraqi schools will be able to improve and do more preparation to shift towards flipped learning in the classroom.
基金support from the National Research Foundation of Korea funded by the Ministry of Education(NRF-2020S1A5A8044620).
文摘Central bank digital currencies(CBDCs),which are legal tenders in digital form,are expected to reduce currency issuance and circulation costs and broaden the scope of monetary policy.In addition,these currencies may also reduce consumers’need for conventional demand deposits,which,in turn,increases banks’loan provision costs because deposits require higher rates of return.We use a microeconomic banking model to investigate the effects of introducing an economy-wide,account-type CBDC on a bank’s loan supply and its failure risk.Given that a CBDC is expected to lower the cost of liquidity circulation and become a strong substitute for demand deposits,both the loan supply and the bank failure risk increase.These increases are countered by subsequent increases in the rates of return on term deposits and loans,which,in turn,reduce the loan supply and thus bank failure risk.These offsetting forces lead to no significant change in banking,as long as the rate of return on loans is below a certain threshold.However,once the rate is above the threshold,bank failure risk increases,thereby undermining banking stability.The problem is more pronounced when the degree of pass-through of funding costs to the loan rate is high and the profitability of a successful project is low.Our results imply that central banks wishing to introduce an economy-wide,account-type CBDC should first monitor yields on bank loans and consider policy measures that induce banks to maintain adequate liquidity reserve levels.
文摘This study investigates the dynamic connectedness between stock indices and the effect of economic policy uncertainty(EPU)in eight countries where COVID-19 was most widespread(China,Italy,France,Germany,Spain,Russia,the US,and the UK)by implementing the time-varying VAR(TVP-VAR)model for daily data over the period spanning from 01/01/2015 to 05/18/2020.Results showed that stock markets were highly connected during the entire period,but the dynamic spillovers reached unprecedented heights during the COVID-19 pandemic in the first quarter of 2020.Moreover,we found that the European stock markets(except Italy)transmitted more spillovers to all other stock markets than they received,primarily during the COVID-19 outbreak.Further analysis using a nonlinear framework showed that the dynamic connectedness was more pronounced for negative than for positive returns.Also,findings showed that the direction of the EPU effect on net connectedness changed during the pandemic onset,indicating that information spillovers from a given market may signal either good or bad news for other markets,depending on the prevailing economic situation.These results have important implications for individual investors,portfolio managers,policymakers,investment banks,and central banks.
文摘The nanoparticle transportation and Brownian diffusion in planar jet flow is simulated via large eddy simulation in this work. To thorough compare the Brownian diffusion with different particle size, we computed three particle diameter dp = 1 nm, 10 nm and 50 nm in one simulation process simultaneously. The numerical results showed that at the flow de- veloping stage, the particle mass concentration pattern develops as the flow vorticity develops. The distribution is nearly uniform at the lower reaches of the nozzle exit. When the jet flow is developing on, vortexes always carry the particle from upstream to downstream, from the central axis region to the outer mixing layer of jet. At the front of the jet flow, particles distribute more homogeneous for they have more residence time to diffuse from higher concentration region to the lower concentration region. The time averaged particle concentration distribution patterns are similar to Gaussian distribution form. The maximum concentration contributed by diffusion is present at the mixing layer near the nozzle exit. The farther away from the nozzle exit in the cross-stream direction, the smaller the concentration is. The maximum concentration contributed by diffusion is several orders smaller than that contributed by flow convection.
基金supported by National Natural Science Foundation of China (Grant No. 50976107)National Key Technology R&D Program of China (Grant No. 2009BAF39B01)the Science Foundation of Zhejiang Sci-Tech University (ZSTU) of China (Grant No. 1003808-Y)
文摘Particle coagulation by Brownian motion is an important but difficult research topic.When particle volume concentration is larger than 0.1%,the classic SMOLUCHOWSKI equation is not applicative anymore.The high concentration coagulation,with HEINE's correction,source terms for the Taylor-series expansion method of moments(TEMOM) are firstly driven in this paper.Ultra-fine particle(d0?100 mm) with initial volume fraction f?1% coagulation in a planar jet turbulence flow is simulated via the large eddy simulation(LES).The instantaneous and time-averaged particle distributions and the high concentration enhancement are given out.The particle number concentration distribution results show that the coagulation is more intense comparing to dilute case in previous research,especially near the nozzle exit.After jet flow is fully developed,the effect is much more obvious at the region between vortexes.The time-averaged γ(the high concentration enhance factor) distributes sharply and symmetrically about the jet centerline at the upstream,but becomes broad and flat at downstream where the cross-stream averaged γ fluctuates drastically.As a new attempt,this paper shows Brownian coagulation with high concentration also can be calculated via TEMOM appropriately,and the coagulation at the region between vortexes is about 1.38 times intensive of the dilute result calculated by the classic Smoluchowski theory.
文摘Online Food Delivery Platforms(OFDPs)has witnessed phenomenal growth in the past few years,especially this year due to the COVID-19 pandemic.This Pandemic has forced many governments across the world to give momentum to OFD services and make their presence among the customers.The Presence of several multinational and national companies in this sector has enhanced the competition and companies are trying to adapt various marketing strategies and exploring the brand experience(BEX)dimension that helps in enhancing the brand equity(BE)of OFDPs.BEXs are critical for building brand loyalty(BL)and making companies profitable.Customers can experience different kinds of brand experiences through feeling,emotions,affection,behavior,and intellect.The present research work is taken up to analyze the factors affecting BEX and its impact on BL and BE of the OFDPs and analyze the mediating role of BL in the relationship between BEX and BE of the OFDPs in the Indian context.A survey of 457 Indian customers was carried out.A questionnaire was used for data collection and a mediation study was used to test hypothesized relationships.Our computational analysis reveals that BEX influences the BL and BE of OFDPs.The study further indicates that BL mediates the relationship between BEX and BE of OFDPs.The effective marketing and relationship management practices will help company to enhance BEX that will enable in enhancing BL and raising BE of their product.It therefore provides a more thorough analysis of BEX constructs and their consequences than previous research.Some of the managerial implication,limitations,and scope of future research are also presented in the study.
文摘Objective: based on the analysis to the elements affecting the results of China's national team in the 2010 mountain outdoor sports adventure challenge race in Abu Dhabi, some theoretical and practical basis on which suggestions are provided on further promoting China's mountain outdoor sports results and the competitive level are given.Subjects: athletic performance of the top six teams and China's national team in 2010 mountain outdoor sports and athletic performance;Methods: using expert interviews, reference and data, mathematical statistics, analyze the athletic performance of the top six teams and China's national team in 2010 mountain outdoor sports and athletic performance on foot and bicycle projects on class projects with the world's top mountain outdoor big gap between sports teams;Result: there are big gaps between China's mountain outdoor sports teams and foreign teams on projects like footing and bicycling;Conclusion: Although in recent years, our mountain outdoor sports performance has been greatly improved, but the large gap do exist on foot and bicycle projects. so these projects need strengthening .
文摘Since the State Council issued The Decision of the State Council on Accelerating the Cultivation and Development of Strategic Emerging Industries and the construction of the Central Plains Economic Zone was regarded as a national strategy, accelerating the cultivation and development of strategic emerging industries has been placed to a prominent position to promote the upgrading of the strategic adjustment of the economic structure and industrial transformation. In this paper, three primary indexes and eight secondary indexes are selected to construct the growth evaluation index system in Henan's strategic emerging industries; Based on Factor Analysis, the enterprise growth of strategic emerging industries in Henan Province was evaluated comprehensively. The conclusion provides a reference for the overall development of strategic emerging industries in Henan.
文摘Endovascular intervention,such as percu-taneous transluminal angioplasty(PTA),improves claudication and saves limbs of patients with severe lower extremity arterial dis-ease(LEAD).[1]A previous study showed that the mortality among octogenarians was as high as 29%regardless of the type of intervention and that re-vascularization was associated with high peripro-cedural mortality.[2]A previous study had already shown that reconstructive surgery for elderly indi-viduals over 80 years old resulted in a significantly higher mortality rate than that for patients between 70 and 80 years old,whereas endovascular inter-vention and primarily conservative treatment had comparable prognoses.[3]Consistently,another study showed that the risks of both overall and am-putation-free survival were significantly lower with endovascular treatment than with bypass surgery in patients with critical limb ischemia.[4]A systematic review and meta-analysis of 27 studies(15 cohort and 12 randomized controlled trials)with 1642 pa-tients suggests that conservative treatment may be considered for nonreconstructable patients with critical limb ischemia;[5]however,because a high risk of bias and serious inconsistencies were found in the included studies,the meta-analysis provided low-quality evidence.In contrast,a small cohort study with 49 patients suggests that amputation im-proved quality of life and health status in fragile elderly individuals.
文摘In order to foster an innovative spirit and ability of high-quality talent, much student research training program in domestic universities will incorporate innovative talent training plan. However, the evaluation mechanism existing research training program is still not perfect for college students, this article has been carrying out a more in-depth discussion and proposes research training program evaluation system for university students.
基金The Ministry of Science and Technology Major Project of China(2017YFC1310903)University of Hong Kong BRC Grant,and Patrick SC Poon Professorship Endowment Fund.
文摘background The risk of symptomatic intracranial haemorrhage(sICH)after thrombolysis is low but severe.Lower dose of alteplase may reduce the risk of sICH.We aim to identify subsets of patients who could benefit from lower dose of alteplase compared with standard dose.Methods Data from two observational registries were pooled together.A total of 3479 patients who had acute ischaemic stroke were entered into the interaction tree model.The response variable was the rate of sICH per the definition of the National Institute of Neurological Disorders and Stroke Study.Clinical improvement was measured by the National Institutes of Health Stroke Scale(NIHSS)and defined as NIHSS 0 or 1 or an improvement of more than 4 points(within 7 days or at discharge).Rare event logistic regression was performed to analyse the OR of safety outcome.results To optimise the interaction effect between tissue plasminogen activator(tPA)dosage(standard/lower)and patient subgroups,three subgroups based on the severity of stroke were identified:(1)NIHSS≤4,(2)NIHSS between 5 and 14,and(3)NIHSS≥15.The estimated difference of OR of having sICH was 2.71(95%CI 0.80 to 7.69,p=0.10)for mild,0.13(95%CI 0.02 to 0.68,p=0.01)for moderate,and 0.65(95%CI 0.19 to 2.55,p=0.52)for severe,respectively.In addition,patients who had moderate stroke treated with lower dose had comparable efficacy outcome(OR 1.23,95%CI 0.71 to 2.13,p=0.45).Conclusion Our analysis demonstrated that in patients who had moderate stroke,lower doses of alteplase are associated with significant sICH reduction and non-inferior performance in efficacy,compared with those in the standard dose group.