The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,...The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,with the influence of transverse magnetic field and thermal radiation.The physical flow problem has been modeled with coupled partial differential equations.We apply similarity transformations to the nondimensionalized equations,and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method.The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints,which are illustrated graphically.The results of the skin friction coefficient and Nusselt number varying different flow parameters are presented in the form of a table.It is observed that the main flow of the hybrid nanofluid,nano particle fraction of silver and Magnesium/water,enhances compared to the mono-nano fluid MgO as the coupling number increases.The application of studies like this can be found in the atomization process of liquids such as centrifugal pumps,viscometers,rotors,fans.展开更多
Background and objective:To provide good health and well-being as established by the Sustainable Development Goal(SDG)3,access to digital technologies can act as conduits to achieve such progress in a population.As gu...Background and objective:To provide good health and well-being as established by the Sustainable Development Goal(SDG)3,access to digital technologies can act as conduits to achieve such progress in a population.As guided by the World Health Organization,antenatal care(ANC)attendance is one of the measures promoted to curtail the global health burden of maternal and infant mortality.ANC services are seldom utilized to their full potential in Zimbabwe.This study explores if any of the women's digital technology characteristics were associated with antenatal care visits.Methods:The study analyzed population-based cross-sectional data with a subsample of 1932 women aged 15-49 years from the 2019 Zimbabwe Multiple Indicator Cluster Survey.Test of associations with chi-square test,bivariate,and multivariate multinomial logistic regression analyses were used to examine the predictors of adequate(4-7)and optimal(≥8)ANC visits relative to undesirable(1-3)antenatal care visits among women who had given births 2 years before the survey.Results:The results indicate that 64.5%(1246/1932)of the women attained adequate ANC while about 9.8%(189/1932)attained optimal ANC.Reading a newspaper/magazine at least once a week(odds ratio[OR] 1.73,β'=0.551,t=2.030,P=0.043)and watching television at least once a week(OR 1.72,β=0.545,t=2.454,P=0.015),listening to the radio less than once a week(OR 1.28,β'=0.247,t=1.750,P=0.080),and owning a mobile phone(OR 1.48,β'=0.394,t=3.020,P=0.003)were positively associated with adequate ANC.Optimal ANC was significantly associated with women being able to read a newspaper at least once a week(OR 2.93,β'=1.074,t=3.120,P=0.002),listen to the radio less than 0nce a week(OR 2.07,p'=0.73,t=2.700,P=0.007)and have ownership of a mobile phone(OR 1.88,β'=0.631,t=2.620,P=0.009).Conclusion:Access to a newspaper,radio,television,and mobile phone were important predictors of a woman's ability to achieve her ANC attendance.Policies to improve the knowledge of ANC packages can be facilitated using digital technology to achieve adequate and preferably optimal ANC in Zimbabwe.It is important to improve digital infrastructure to support digital technologies in providing ANC services.展开更多
The study examined the mediating effect of corporate governance on the relationship between accounting information and stock market returns of listed entities on the Ghana Stock Exchange.The population of the study wa...The study examined the mediating effect of corporate governance on the relationship between accounting information and stock market returns of listed entities on the Ghana Stock Exchange.The population of the study was forty(40)listed entities from 2007-2019 with 520 firm-year observations.The study applied a panel regression model that takes unobserved individual heterogeneity and distributional heterogeneity into consideration.In addition,the study employed cross-section dependence test,Levin-Lin-Chu,ImPesaran,Pesaran,Kao,and Larsson cointegration test,fully modified ordinary least square(FMOLS),and dynamic ordinary least square(DOLS).The results of unit root test showed that all the variables are integrated at first difference.Moreover,the results of cointegration test revealed that accounting information variables were cointegrated in the long run.The result of FMOLS and DOLS further revealed that all the accounting information variables with the exception of OCFPS and NTA have a direct insignificant relationship with the stock market return.The study revealed that corporate governance which was proxied by board size also strengthens the relationship between TAT and stock market return and NTA and stock market return at 5%significant level under FMOLS and DOLS respectively.展开更多
A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate...A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.展开更多
Clinical methods are used for diagnosing COVID-19 infected patients,but reports posit that,several people who were initially tested positive of COVID-19,and who had some underlying diseases,turned out having negative ...Clinical methods are used for diagnosing COVID-19 infected patients,but reports posit that,several people who were initially tested positive of COVID-19,and who had some underlying diseases,turned out having negative results after further tests.Therefore,the performance of clinical methods is not always guaranteed.Moreover,chest X-ray image data of COVID-19 infected patients are mostly used in the computational models for COVID-19 diagnosis,while the use of common symptoms,such as fever,cough,fatigue,muscle aches,headache,etc.in computational models is not yet reported.In this study,we employed seven classification algorithms to empirically test and verify their efficacy when applied to diagnose COVID-19 using the aforementioned symptoms.We experimented with Logistic Regression(LR),Support Vector Machine(SVM),Naïve Byes(NB),Decision Tree(DT),Multilayer Perceptron(MLP),Fuzzy Cognitive Map(FCM)and Deep Neural Network(DNN)algorithms.The techniques were subjected to random undersampling and oversampling.Our results showed that with class imbalance,MLP and DNN outperform others.However,without class imbalance,MLP,FCM and DNN outperform others with the use of random undersampling,but DNN has the best performance by utilizing random oversampling.This study identified MLP,FCM and DNN as better classifiers over LR,NB,DT and SVM,so that healthcare software system developers can adopt them to develop intelligence-based expert systems which both medical personnel and patients can use for differential diagnosis of COVID-19 based on the aforementioned symptoms.However,the test of performance must not be limited to the traditional performance metrics.展开更多
A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determine...A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determined using either row wise or column wise operations and are demonstrated to be sums of permutation products of the Gauss pivot row multipliers. These sums of permutation products can be constructed using a tree structure that can be easily memorized or alternatively computed using matrix products. The method requires only storage of the L matrix which is half in size compared to storage of the elements in the LU decomposition. Equivalence of the proposed method with both the Gauss elimination and LU decomposition is also shown in this paper.展开更多
Prostate cancer(PCa)symptoms are commonly confused with benign prostate hyperplasia(BPH),particularly in the early stages due to similarities between symptoms,and in some instances,underdiagnoses.Clinical methods have...Prostate cancer(PCa)symptoms are commonly confused with benign prostate hyperplasia(BPH),particularly in the early stages due to similarities between symptoms,and in some instances,underdiagnoses.Clinical methods have been utilized to diagnose PCa;however,at the full-blown stage,clinical methods usually present high risks of complicated side effects.Therefore,we proposed the use of support vector machine for early differential diagnosis of PCa(SVM-PCa-EDD).SVM was used to classify persons with and without PCa.We used the PCa dataset from the Kaggle Healthcare repository to develop and validate SVM model for classification.The PCa dataset consisted of 250 features and one class of features.Attributes considered in this study were age,body mass index(BMI),race,family history,obesity,trouble urinating,urine stream force,blood in semen,bone pain,and erectile dysfunction.The SVM-PCa-EDD was used for preprocessing the PCa dataset,specifically dealing with class imbalance,and for dimensionality reduction.After eliminating class imbalance,the area under the receiver operating characteristic(ROC)curve(AUC)of the logistic regression(LR)model trained with the downsampled dataset was 58.4%,whereas that of the AUC-ROC of LR trained with the class imbalance dataset was 54.3%.The SVM-PCa-EDD achieved 90%accuracy,80%sensitivity,and 80%specificity.The validation of SVM-PCa-EDD using random forest and LR showed that SVM-PCa-EDD performed better in early differential diagnosis of PCa.The proposed model can assist medical experts in early diagnosis of PCa,particularly in resource-constrained healthcare settings and making further recommendations for PCa testing and treatment.展开更多
Emerging digital technologies continues to evolve posing unprecedented opportunities in health systems globally to improve healthcare services delivery.There has been significant progress in healthcare.However,the lac...Emerging digital technologies continues to evolve posing unprecedented opportunities in health systems globally to improve healthcare services delivery.There has been significant progress in healthcare.However,the lack of emotive recognition coupled with a dearth of personalized and pervasive health applications and emotive smart devices calls for the integration of intelligent sensors health systems through emerging technologies.Although there has been significant progress in smart and connected health care,more research innovation,dissemination and technologies are needed to unbundle new opportunities and move towards healthcare 5.0.Healthcare is at the dawn of a paradigm change to reach the new era of smart disease control and detection,virtual care,smart health management,smart monitoring,and decision-making.Therefore,this study discusses the roles and capacities of sensors,their capabilities and other emerging technologies such as nanotechnology,5 G technologies,drone technology,blockchain,robotics,big data,internet of things,artificial intelligence,and cloud computing.Healthcare 5.0 provides healthcare services including patient remote monitoring.tracking and virtual clinics,emotive telemedicine,ambient assisted living,smart self-management,wellness monitoring and control,smart treatment reminders,compliance and adherence,and personalized and connected health care.However,building resilience and robust healthcare 5.0 is not immune to challenges.Organizational challenges,technological and infrastructural barriers,lack of legal and regulatory frameworks and e-health policies,individual perceptions,misalignment with hospitals'strategy,lack of funding,religious and cultural bariers are identified as potential barriers to the successful implementation of healthcare 5.0.Therefore,there is a need for building resilient technology-driven healthcare systems.To achieve this,there is a need for expanding technological infrastructure,provision of budgetary support based on sustainable business models,develop appropriate legal and e-health policies,standardization and synchronization of protocols,improving stakeholders'engagement and involvement and establishment of private and public partnerships and investments.展开更多
Aims:To identify virtual healthcare services and digital health technologies deployed in South Africa during coronavirus disease 2019(COVID-19)and the challenges associated with their use.Metiiods:To determine the sta...Aims:To identify virtual healthcare services and digital health technologies deployed in South Africa during coronavirus disease 2019(COVID-19)and the challenges associated with their use.Metiiods:To determine the status of digital health utilization during COVID-19 in South Africa,the preferred reporting items for systematic reviews and meta-analyses model was used to perform a systematic and in-depth critical analysis of previously published studies in well-known and trusted online electronic databases using specific search keywords words that are relevant to this study.We selected published peer-reviewed articles available from the onset of COVID-19 to July 2021.Results:Total of 24 articles were included into this study.This study revealed that South Africa adopted digital technologies such as SMS-based solutions,mobile health applications,telemedicine and telehealth,WhatsApp-based systems,artificial intelligence and chatbots and robotics to provide healthcare services during COVID-19 pandemic.These innovative technologies have been used for various purposes including screening infectious and non-infectious diseases,disease surveillance and monitoring,medication and treatment compliance,creating awareness and communication.The study also revealed that teleconsultation and e-prescription,telelaboratory and telepharmacy,teleeducation and teletraining,teledermatology,teleradiology,telecardiology,teleophthalmology,teleneurology,telerehabilitation,teleoncology and telepsychiatry are among virtual healthcare services delivered through digital health technologies during COVID-19 in South Africa.However,these smart digital health technologies face several impediments such as infrastructural and technological barriers,organization and financial barriers,policy and regulatory barriers as well as cultural barriers.Conclusion:Although COVID-19 has invigorated the use of digital health technologies,there are still some shortcomings.The outbreak of pandemics like COVID-19 in the future is not inevitable.Therefore,we recommend increasing community networks in rural areas to bridge the digital divide and the modification of mHealth policy to advocate for the effective use of innovative technologies in healthcare and the development of sustainable strategies for resources mobilization through private-public partnerships as well as joining available international initiatives advocating for smart digital health.展开更多
A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built s...A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built self-adjustment of flow rates among the filters assisted with downstream orifice for flow control with limited flexibility for further adjustment. The proposed design allows the control of flow level and flow rates in individual filters, the water level in the over flow distributor tank and offers increased flexibility in responding to changes in filtration variables and optimising the overall performance of the filters. The design set up can also operate as constant rate filter through setting the water level in the distributor tank to the maximum.展开更多
The study examined the relationship between accounting information and stock market returns of listed financial entities on the Ghana Stock Exchange using board size as a mediating variable.The population of the study...The study examined the relationship between accounting information and stock market returns of listed financial entities on the Ghana Stock Exchange using board size as a mediating variable.The population of the study was 13 listed financial entities from 2007-2019 with 169 firm-year observations.This study applied a panel regression model that takes unobserved individual heterogeneity and distributional heterogeneity into consideration.In addition,the study employed cross-section dependence test;Levin-Lin-Chu(LLC),ImPesaran,Pesaran,Kao,and Larsson cointegration test;Fully Modified Ordinary Least Square(FMOLS)and Dynamic Ordinary Least Square(DOLS).The results of the unit root test showed that all the variables were integrated at first difference.Moreover,the results of cointegration test revealed that accounting information variables were cointegrated in the long run.The result of FMOLS and DOLS revealed that all the accounting information variables with the exception of operating cash flow per share(OCFPS)and net tangible assets(NTA)have a direct insignificant relationship with the stock market return of listed financial entities.The study revealed that board size strengthens the relationship between OCFPS and NTA,and stock market return at 5%significant level under FMOLS and DOLS of listed financial entities.展开更多
Introduction:Understanding the environmental factors that influence riparian vegetation community composition and distribution is important for understanding wetland ecosystem functioning.This understanding can furthe...Introduction:Understanding the environmental factors that influence riparian vegetation community composition and distribution is important for understanding wetland ecosystem functioning.This understanding can further serve to inform policy aimed at conserving wetlands such as the Okavango Delta.In the Okavango Delta,information on the influence of distance from surface water on vegetation community composition and structure is limited.The objective of this study was to determine the relationship between distance from surface water and riparian plant communities at different sites in the Okavango Delta.Methods:Vegetation sampling was conducted in four sites in 20 m×10 m belted plots placed perpendicular to the river bank at 0–10 m,10–20 m,20–30 m,30–40 m,and 40–50 m distance classes.At each site,10–15 plots were sampled at each distance class.Basal area,species richness,cover,and plant diversity were determined for each plot.Indicator species analysis was used to determine the characteristic species at each distance class.One-way analysis of variance and Tukey post hoc analyses were used to compare species diversity,richness,cover,and basal area between distance classes.Generalized linear mixed(GLM)model was used to test for the overall impact of site and distance on each plant parameter.Results:Mean species richness was significantly(p<0.05)higher at 0–10 m than at 20–30 m,30–40 m,and 40–50 m in Boro.There was no significant difference within other sites.Mean species diversity also varied significantly(p<0.05)in Boro where it was higher at 0–10 m and 10–20 m than at 30–40 m.Mean basal area differed significantly within Jao and Upper Panhandle.In Jao,it was higher(p<0.05)at 0–10 m than at other distance classes.Mean percentage canopy cover differed significantly within all sites.In addition to this,plant species composition also changed along distance from surface water within each site.From GLM analysis,both distance and site significantly(p<0.05)influenced diversity and basal area.Species richness and cover were significantly(p<0.05)influenced by site only.Conclusion:Distance from surface water and site are important determinants of riparian plant dynamics in the Okavango Delta.展开更多
This work examines a mathematical model of COVID-19 among two subgroups:low-risk and high-risk populations with two preventive measures;non-pharmaceutical interventions including wearing masks,maintaining social dista...This work examines a mathematical model of COVID-19 among two subgroups:low-risk and high-risk populations with two preventive measures;non-pharmaceutical interventions including wearing masks,maintaining social distance,and washing hands regularly by the low-risk group.In addition to the interventions mentioned above,highrisk individuals must take extra precaution measures,including telework,avoiding social gathering or public places,etc.to reduce the transmission.Those with underlying chronic diseases and the elderly(ages 60 and above)were classified as high-risk individuals and the rest as low-risk individuals.The parameter values used in this study were estimated using the available data from the Johns Hopkins University on COVID-19 for Brazil and South Africa.We evaluated the effective reproduction number for the two countries and observed how the various parameters affected the effective reproduction number.We also performed numerical simulations and analysis of the model.Susceptible and infectious populations for both low-risk and high-risk individuals were studied in detail.Results were displayed in both graphical and table forms to show the dynamics of each country being studied.We observed that non-pharmaceutical interventions by highrisk individuals significantly reduce infections among only high-risk individuals.In contrast,non-pharmaceutical interventions by low-risk individuals have a significant reduction in infections in both subgroups.Therefore,low-risk individuals’preventive actions have a considerable effect on reducing infections,even among high-risk individuals.展开更多
The novel coronavirus(COVID-19)outbreak emerged in December 2019.The disease has caused loss of many lives and has become an unprecedented threat to public health worldwide.We develop simple COVID-19 epidemic models t...The novel coronavirus(COVID-19)outbreak emerged in December 2019.The disease has caused loss of many lives and has become an unprecedented threat to public health worldwide.We develop simple COVID-19 epidemic models to study treatment strategies to control the pandemic.The results show that eradication of the disease is possible if the efficacy of treatment is perfect.We also investigate the existence of a dual-rate effect.Conditions under which the effect occurs are derived.When the effect is present,a tactic to control the infection might be to initially treat infected individuals aggressively at a relatively high rate to drive the prevalence to a lower region that can be maintained in the long run at a relatively moderate rate and cost.展开更多
文摘The present paper examines the temperature-dependent viscosity and thermal conductivity of a micropolar silver(Ag)−Magnesium oxide(MgO)hybrid nanofluid made of silver and magnesium oxide over a rotating vertical cone,with the influence of transverse magnetic field and thermal radiation.The physical flow problem has been modeled with coupled partial differential equations.We apply similarity transformations to the nondimensionalized equations,and the resulting nonlinear differential equations are solved using overlapping grid multidomain spectral quasilinearization method.The flow behavior for the fluid is scrutinized under the impact of diverse physical constraints,which are illustrated graphically.The results of the skin friction coefficient and Nusselt number varying different flow parameters are presented in the form of a table.It is observed that the main flow of the hybrid nanofluid,nano particle fraction of silver and Magnesium/water,enhances compared to the mono-nano fluid MgO as the coupling number increases.The application of studies like this can be found in the atomization process of liquids such as centrifugal pumps,viscometers,rotors,fans.
文摘Background and objective:To provide good health and well-being as established by the Sustainable Development Goal(SDG)3,access to digital technologies can act as conduits to achieve such progress in a population.As guided by the World Health Organization,antenatal care(ANC)attendance is one of the measures promoted to curtail the global health burden of maternal and infant mortality.ANC services are seldom utilized to their full potential in Zimbabwe.This study explores if any of the women's digital technology characteristics were associated with antenatal care visits.Methods:The study analyzed population-based cross-sectional data with a subsample of 1932 women aged 15-49 years from the 2019 Zimbabwe Multiple Indicator Cluster Survey.Test of associations with chi-square test,bivariate,and multivariate multinomial logistic regression analyses were used to examine the predictors of adequate(4-7)and optimal(≥8)ANC visits relative to undesirable(1-3)antenatal care visits among women who had given births 2 years before the survey.Results:The results indicate that 64.5%(1246/1932)of the women attained adequate ANC while about 9.8%(189/1932)attained optimal ANC.Reading a newspaper/magazine at least once a week(odds ratio[OR] 1.73,β'=0.551,t=2.030,P=0.043)and watching television at least once a week(OR 1.72,β=0.545,t=2.454,P=0.015),listening to the radio less than once a week(OR 1.28,β'=0.247,t=1.750,P=0.080),and owning a mobile phone(OR 1.48,β'=0.394,t=3.020,P=0.003)were positively associated with adequate ANC.Optimal ANC was significantly associated with women being able to read a newspaper at least once a week(OR 2.93,β'=1.074,t=3.120,P=0.002),listen to the radio less than 0nce a week(OR 2.07,p'=0.73,t=2.700,P=0.007)and have ownership of a mobile phone(OR 1.88,β'=0.631,t=2.620,P=0.009).Conclusion:Access to a newspaper,radio,television,and mobile phone were important predictors of a woman's ability to achieve her ANC attendance.Policies to improve the knowledge of ANC packages can be facilitated using digital technology to achieve adequate and preferably optimal ANC in Zimbabwe.It is important to improve digital infrastructure to support digital technologies in providing ANC services.
文摘The study examined the mediating effect of corporate governance on the relationship between accounting information and stock market returns of listed entities on the Ghana Stock Exchange.The population of the study was forty(40)listed entities from 2007-2019 with 520 firm-year observations.The study applied a panel regression model that takes unobserved individual heterogeneity and distributional heterogeneity into consideration.In addition,the study employed cross-section dependence test,Levin-Lin-Chu,ImPesaran,Pesaran,Kao,and Larsson cointegration test,fully modified ordinary least square(FMOLS),and dynamic ordinary least square(DOLS).The results of unit root test showed that all the variables are integrated at first difference.Moreover,the results of cointegration test revealed that accounting information variables were cointegrated in the long run.The result of FMOLS and DOLS further revealed that all the accounting information variables with the exception of OCFPS and NTA have a direct insignificant relationship with the stock market return.The study revealed that corporate governance which was proxied by board size also strengthens the relationship between TAT and stock market return and NTA and stock market return at 5%significant level under FMOLS and DOLS respectively.
文摘A variable chlorine decay rate modeling of the Matsapha town water network was developed based on initial chlorine dosages. The model was adequately described by a second order rate function of the chlorine decay rate with respect to the initial chlorine dose applied. Simulations of chlorine residuals within the Matsapha water distribution network were run using the EPANET 2.0 program at different initial chlorine dosages and using the variable decay rate as described by the second order model. The measurement results indicated that the use of constant decay rate tended to underestimate chlorine residuals leading to potentially excess dosages with the associated chemical cost and side effects. The error between the two rate models varied between 0% and 15%. It is suggested that the use of water quality simulation programs such as EPANET be enhanced through the extension programs that accommodate variable rate modeling of chlorine residuals within distribution systems.
文摘Clinical methods are used for diagnosing COVID-19 infected patients,but reports posit that,several people who were initially tested positive of COVID-19,and who had some underlying diseases,turned out having negative results after further tests.Therefore,the performance of clinical methods is not always guaranteed.Moreover,chest X-ray image data of COVID-19 infected patients are mostly used in the computational models for COVID-19 diagnosis,while the use of common symptoms,such as fever,cough,fatigue,muscle aches,headache,etc.in computational models is not yet reported.In this study,we employed seven classification algorithms to empirically test and verify their efficacy when applied to diagnose COVID-19 using the aforementioned symptoms.We experimented with Logistic Regression(LR),Support Vector Machine(SVM),Naïve Byes(NB),Decision Tree(DT),Multilayer Perceptron(MLP),Fuzzy Cognitive Map(FCM)and Deep Neural Network(DNN)algorithms.The techniques were subjected to random undersampling and oversampling.Our results showed that with class imbalance,MLP and DNN outperform others.However,without class imbalance,MLP,FCM and DNN outperform others with the use of random undersampling,but DNN has the best performance by utilizing random oversampling.This study identified MLP,FCM and DNN as better classifiers over LR,NB,DT and SVM,so that healthcare software system developers can adopt them to develop intelligence-based expert systems which both medical personnel and patients can use for differential diagnosis of COVID-19 based on the aforementioned symptoms.However,the test of performance must not be limited to the traditional performance metrics.
文摘A method for solving systems of linear equations is presented based on direct decomposition of the coefficient matrix using the form LAX = LB = B’ . Elements of the reducing lower triangular matrix L can be determined using either row wise or column wise operations and are demonstrated to be sums of permutation products of the Gauss pivot row multipliers. These sums of permutation products can be constructed using a tree structure that can be easily memorized or alternatively computed using matrix products. The method requires only storage of the L matrix which is half in size compared to storage of the elements in the LU decomposition. Equivalence of the proposed method with both the Gauss elimination and LU decomposition is also shown in this paper.
文摘Prostate cancer(PCa)symptoms are commonly confused with benign prostate hyperplasia(BPH),particularly in the early stages due to similarities between symptoms,and in some instances,underdiagnoses.Clinical methods have been utilized to diagnose PCa;however,at the full-blown stage,clinical methods usually present high risks of complicated side effects.Therefore,we proposed the use of support vector machine for early differential diagnosis of PCa(SVM-PCa-EDD).SVM was used to classify persons with and without PCa.We used the PCa dataset from the Kaggle Healthcare repository to develop and validate SVM model for classification.The PCa dataset consisted of 250 features and one class of features.Attributes considered in this study were age,body mass index(BMI),race,family history,obesity,trouble urinating,urine stream force,blood in semen,bone pain,and erectile dysfunction.The SVM-PCa-EDD was used for preprocessing the PCa dataset,specifically dealing with class imbalance,and for dimensionality reduction.After eliminating class imbalance,the area under the receiver operating characteristic(ROC)curve(AUC)of the logistic regression(LR)model trained with the downsampled dataset was 58.4%,whereas that of the AUC-ROC of LR trained with the class imbalance dataset was 54.3%.The SVM-PCa-EDD achieved 90%accuracy,80%sensitivity,and 80%specificity.The validation of SVM-PCa-EDD using random forest and LR showed that SVM-PCa-EDD performed better in early differential diagnosis of PCa.The proposed model can assist medical experts in early diagnosis of PCa,particularly in resource-constrained healthcare settings and making further recommendations for PCa testing and treatment.
文摘Emerging digital technologies continues to evolve posing unprecedented opportunities in health systems globally to improve healthcare services delivery.There has been significant progress in healthcare.However,the lack of emotive recognition coupled with a dearth of personalized and pervasive health applications and emotive smart devices calls for the integration of intelligent sensors health systems through emerging technologies.Although there has been significant progress in smart and connected health care,more research innovation,dissemination and technologies are needed to unbundle new opportunities and move towards healthcare 5.0.Healthcare is at the dawn of a paradigm change to reach the new era of smart disease control and detection,virtual care,smart health management,smart monitoring,and decision-making.Therefore,this study discusses the roles and capacities of sensors,their capabilities and other emerging technologies such as nanotechnology,5 G technologies,drone technology,blockchain,robotics,big data,internet of things,artificial intelligence,and cloud computing.Healthcare 5.0 provides healthcare services including patient remote monitoring.tracking and virtual clinics,emotive telemedicine,ambient assisted living,smart self-management,wellness monitoring and control,smart treatment reminders,compliance and adherence,and personalized and connected health care.However,building resilience and robust healthcare 5.0 is not immune to challenges.Organizational challenges,technological and infrastructural barriers,lack of legal and regulatory frameworks and e-health policies,individual perceptions,misalignment with hospitals'strategy,lack of funding,religious and cultural bariers are identified as potential barriers to the successful implementation of healthcare 5.0.Therefore,there is a need for building resilient technology-driven healthcare systems.To achieve this,there is a need for expanding technological infrastructure,provision of budgetary support based on sustainable business models,develop appropriate legal and e-health policies,standardization and synchronization of protocols,improving stakeholders'engagement and involvement and establishment of private and public partnerships and investments.
文摘Aims:To identify virtual healthcare services and digital health technologies deployed in South Africa during coronavirus disease 2019(COVID-19)and the challenges associated with their use.Metiiods:To determine the status of digital health utilization during COVID-19 in South Africa,the preferred reporting items for systematic reviews and meta-analyses model was used to perform a systematic and in-depth critical analysis of previously published studies in well-known and trusted online electronic databases using specific search keywords words that are relevant to this study.We selected published peer-reviewed articles available from the onset of COVID-19 to July 2021.Results:Total of 24 articles were included into this study.This study revealed that South Africa adopted digital technologies such as SMS-based solutions,mobile health applications,telemedicine and telehealth,WhatsApp-based systems,artificial intelligence and chatbots and robotics to provide healthcare services during COVID-19 pandemic.These innovative technologies have been used for various purposes including screening infectious and non-infectious diseases,disease surveillance and monitoring,medication and treatment compliance,creating awareness and communication.The study also revealed that teleconsultation and e-prescription,telelaboratory and telepharmacy,teleeducation and teletraining,teledermatology,teleradiology,telecardiology,teleophthalmology,teleneurology,telerehabilitation,teleoncology and telepsychiatry are among virtual healthcare services delivered through digital health technologies during COVID-19 in South Africa.However,these smart digital health technologies face several impediments such as infrastructural and technological barriers,organization and financial barriers,policy and regulatory barriers as well as cultural barriers.Conclusion:Although COVID-19 has invigorated the use of digital health technologies,there are still some shortcomings.The outbreak of pandemics like COVID-19 in the future is not inevitable.Therefore,we recommend increasing community networks in rural areas to bridge the digital divide and the modification of mHealth policy to advocate for the effective use of innovative technologies in healthcare and the development of sustainable strategies for resources mobilization through private-public partnerships as well as joining available international initiatives advocating for smart digital health.
文摘A declining rate filter operating through over flow control mode is proposed in this paper with a view to improving the overall performance of declining rate filters. Traditional declining rate filters have in-built self-adjustment of flow rates among the filters assisted with downstream orifice for flow control with limited flexibility for further adjustment. The proposed design allows the control of flow level and flow rates in individual filters, the water level in the over flow distributor tank and offers increased flexibility in responding to changes in filtration variables and optimising the overall performance of the filters. The design set up can also operate as constant rate filter through setting the water level in the distributor tank to the maximum.
文摘The study examined the relationship between accounting information and stock market returns of listed financial entities on the Ghana Stock Exchange using board size as a mediating variable.The population of the study was 13 listed financial entities from 2007-2019 with 169 firm-year observations.This study applied a panel regression model that takes unobserved individual heterogeneity and distributional heterogeneity into consideration.In addition,the study employed cross-section dependence test;Levin-Lin-Chu(LLC),ImPesaran,Pesaran,Kao,and Larsson cointegration test;Fully Modified Ordinary Least Square(FMOLS)and Dynamic Ordinary Least Square(DOLS).The results of the unit root test showed that all the variables were integrated at first difference.Moreover,the results of cointegration test revealed that accounting information variables were cointegrated in the long run.The result of FMOLS and DOLS revealed that all the accounting information variables with the exception of operating cash flow per share(OCFPS)and net tangible assets(NTA)have a direct insignificant relationship with the stock market return of listed financial entities.The study revealed that board size strengthens the relationship between OCFPS and NTA,and stock market return at 5%significant level under FMOLS and DOLS of listed financial entities.
基金This study which is part of GT’s PhD work was sponsored by the German Federal Ministry for Education and Research(BMBF).
文摘Introduction:Understanding the environmental factors that influence riparian vegetation community composition and distribution is important for understanding wetland ecosystem functioning.This understanding can further serve to inform policy aimed at conserving wetlands such as the Okavango Delta.In the Okavango Delta,information on the influence of distance from surface water on vegetation community composition and structure is limited.The objective of this study was to determine the relationship between distance from surface water and riparian plant communities at different sites in the Okavango Delta.Methods:Vegetation sampling was conducted in four sites in 20 m×10 m belted plots placed perpendicular to the river bank at 0–10 m,10–20 m,20–30 m,30–40 m,and 40–50 m distance classes.At each site,10–15 plots were sampled at each distance class.Basal area,species richness,cover,and plant diversity were determined for each plot.Indicator species analysis was used to determine the characteristic species at each distance class.One-way analysis of variance and Tukey post hoc analyses were used to compare species diversity,richness,cover,and basal area between distance classes.Generalized linear mixed(GLM)model was used to test for the overall impact of site and distance on each plant parameter.Results:Mean species richness was significantly(p<0.05)higher at 0–10 m than at 20–30 m,30–40 m,and 40–50 m in Boro.There was no significant difference within other sites.Mean species diversity also varied significantly(p<0.05)in Boro where it was higher at 0–10 m and 10–20 m than at 30–40 m.Mean basal area differed significantly within Jao and Upper Panhandle.In Jao,it was higher(p<0.05)at 0–10 m than at other distance classes.Mean percentage canopy cover differed significantly within all sites.In addition to this,plant species composition also changed along distance from surface water within each site.From GLM analysis,both distance and site significantly(p<0.05)influenced diversity and basal area.Species richness and cover were significantly(p<0.05)influenced by site only.Conclusion:Distance from surface water and site are important determinants of riparian plant dynamics in the Okavango Delta.
文摘This work examines a mathematical model of COVID-19 among two subgroups:low-risk and high-risk populations with two preventive measures;non-pharmaceutical interventions including wearing masks,maintaining social distance,and washing hands regularly by the low-risk group.In addition to the interventions mentioned above,highrisk individuals must take extra precaution measures,including telework,avoiding social gathering or public places,etc.to reduce the transmission.Those with underlying chronic diseases and the elderly(ages 60 and above)were classified as high-risk individuals and the rest as low-risk individuals.The parameter values used in this study were estimated using the available data from the Johns Hopkins University on COVID-19 for Brazil and South Africa.We evaluated the effective reproduction number for the two countries and observed how the various parameters affected the effective reproduction number.We also performed numerical simulations and analysis of the model.Susceptible and infectious populations for both low-risk and high-risk individuals were studied in detail.Results were displayed in both graphical and table forms to show the dynamics of each country being studied.We observed that non-pharmaceutical interventions by highrisk individuals significantly reduce infections among only high-risk individuals.In contrast,non-pharmaceutical interventions by low-risk individuals have a significant reduction in infections in both subgroups.Therefore,low-risk individuals’preventive actions have a considerable effect on reducing infections,even among high-risk individuals.
文摘The novel coronavirus(COVID-19)outbreak emerged in December 2019.The disease has caused loss of many lives and has become an unprecedented threat to public health worldwide.We develop simple COVID-19 epidemic models to study treatment strategies to control the pandemic.The results show that eradication of the disease is possible if the efficacy of treatment is perfect.We also investigate the existence of a dual-rate effect.Conditions under which the effect occurs are derived.When the effect is present,a tactic to control the infection might be to initially treat infected individuals aggressively at a relatively high rate to drive the prevalence to a lower region that can be maintained in the long run at a relatively moderate rate and cost.
