In this study, we examine the hydrodynamic characteristics of three rows of vertical slotted wall breakwaters in which the front and middle walls are permeable and partially immersed in a water channel of constant dep...In this study, we examine the hydrodynamic characteristics of three rows of vertical slotted wall breakwaters in which the front and middle walls are permeable and partially immersed in a water channel of constant depth, whereas the third wall is impermeable. The wave–structure interaction and flow behavior of this type of breakwater arrangement are complicated and must be analyzed before breakwaters can be appropriately designed. To study the hydrodynamic breakwater performance, we developed a mathematical model based on the eigenfunction expansion method and a least squares technique for predicting wave interaction with three rows of vertical slotted wall breakwaters. We theoretically examined the wave transmission, reflection, energy loss, wave runup, and wave force under normal regular waves. Comparisons with experimental measurements show that the mathematical model results adequately reproduce most of the important features. The results of this investigation provide a better understanding of the hydrodynamic performance of triple-row vertical slotted wall breakwaters.展开更多
Malaysia is faced with a high HIV/AIDS burden that poses a public health threat.We constructed and applied a compartmental model to understand the spread and control of HIV/AIDS in Malaysia.A simple model for HIV and ...Malaysia is faced with a high HIV/AIDS burden that poses a public health threat.We constructed and applied a compartmental model to understand the spread and control of HIV/AIDS in Malaysia.A simple model for HIV and AIDS disease that incorporates condom and uncontaminated needle-syringes interventions and addresses the relative impact of given treatment therapy for infected HIV newborns on reducing HIV and AIDS incidence is presented.We demonstrated how treatment therapy for new-born babies and the use of condoms or uncontaminated needle-syringes impact the dynamics of HIV in Malaysia.The model was calibrated to HIV and AIDS incidence data from Malaysia from 1986 to 2011.The epidemiological parameters are estimated using Bayesian inference via Markov chain Monte Carlo simulation method.The reproduction number optimal for control of the HIV/AIDS disease obtained suggests that the disease-free equilibrium was unstable during the 25 years.However,the results indicated that the use of condoms and uncontaminated needle-syringes are pivotal intervention control strategies;a comprehensive adoption of the intervention may help stop the spread of HIV disease.Treatment therapy for newborn babies is also of high value;it reduces the epidemic peak.The combined effect of condom use or uncontaminated needle-syringe is more pronounced in controlling the spread of HIV/AIDS.展开更多
In this paper,we present the impact of migration on the spread of HIV and AIDS cases.A simple model for HIV and AIDS that incorporates migration and addresses its contributions to the spread of HIV and AIDS cases was ...In this paper,we present the impact of migration on the spread of HIV and AIDS cases.A simple model for HIV and AIDS that incorporates migration and addresses its contributions to the spread of HIV and AIDS cases was constructed.The model was calibrated to HIV and AIDS incidence data from Malaysia.We explore the use of Markov chain Monte Carlo(MCMC)simulation method to estimate uncertainty in all the unknown parameters incorporated in our proposed model.Among the migrant population,1.5572e-01 were susceptible to HIV transmission,which constituted 67,801 migrants.A proportion of migrants,6.3773e-04,were estimated to be HIV infected,constituting 278 migrants.There were 72(per 10,000)migrants estimated to have had AIDS,representing a proportion of 1.6611e-08.The result suggests that the disease-free steady state was unstable since the estimated basic reproduction number R0 was 2.0906 and 2.3322 for the models without and with migration,respectively.This is not a good indicator from the public health point of view,as the aim is to stabilize the epidemic at the disease-free equilibrium.The advantage of introduction of migration to the simple model validated the true R0 and the transmission rate b associated with HIV and AIDS epidemic disease in Malaysia.It also indicates an approximately 12 percentage points increase in the rate of HIV infection with migration.展开更多
基金King Abdul-Aziz City for Science and Technology,General Directorate of Research Grants Programs(LGP-35-287)
文摘In this study, we examine the hydrodynamic characteristics of three rows of vertical slotted wall breakwaters in which the front and middle walls are permeable and partially immersed in a water channel of constant depth, whereas the third wall is impermeable. The wave–structure interaction and flow behavior of this type of breakwater arrangement are complicated and must be analyzed before breakwaters can be appropriately designed. To study the hydrodynamic breakwater performance, we developed a mathematical model based on the eigenfunction expansion method and a least squares technique for predicting wave interaction with three rows of vertical slotted wall breakwaters. We theoretically examined the wave transmission, reflection, energy loss, wave runup, and wave force under normal regular waves. Comparisons with experimental measurements show that the mathematical model results adequately reproduce most of the important features. The results of this investigation provide a better understanding of the hydrodynamic performance of triple-row vertical slotted wall breakwaters.
文摘Malaysia is faced with a high HIV/AIDS burden that poses a public health threat.We constructed and applied a compartmental model to understand the spread and control of HIV/AIDS in Malaysia.A simple model for HIV and AIDS disease that incorporates condom and uncontaminated needle-syringes interventions and addresses the relative impact of given treatment therapy for infected HIV newborns on reducing HIV and AIDS incidence is presented.We demonstrated how treatment therapy for new-born babies and the use of condoms or uncontaminated needle-syringes impact the dynamics of HIV in Malaysia.The model was calibrated to HIV and AIDS incidence data from Malaysia from 1986 to 2011.The epidemiological parameters are estimated using Bayesian inference via Markov chain Monte Carlo simulation method.The reproduction number optimal for control of the HIV/AIDS disease obtained suggests that the disease-free equilibrium was unstable during the 25 years.However,the results indicated that the use of condoms and uncontaminated needle-syringes are pivotal intervention control strategies;a comprehensive adoption of the intervention may help stop the spread of HIV disease.Treatment therapy for newborn babies is also of high value;it reduces the epidemic peak.The combined effect of condom use or uncontaminated needle-syringe is more pronounced in controlling the spread of HIV/AIDS.
文摘In this paper,we present the impact of migration on the spread of HIV and AIDS cases.A simple model for HIV and AIDS that incorporates migration and addresses its contributions to the spread of HIV and AIDS cases was constructed.The model was calibrated to HIV and AIDS incidence data from Malaysia.We explore the use of Markov chain Monte Carlo(MCMC)simulation method to estimate uncertainty in all the unknown parameters incorporated in our proposed model.Among the migrant population,1.5572e-01 were susceptible to HIV transmission,which constituted 67,801 migrants.A proportion of migrants,6.3773e-04,were estimated to be HIV infected,constituting 278 migrants.There were 72(per 10,000)migrants estimated to have had AIDS,representing a proportion of 1.6611e-08.The result suggests that the disease-free steady state was unstable since the estimated basic reproduction number R0 was 2.0906 and 2.3322 for the models without and with migration,respectively.This is not a good indicator from the public health point of view,as the aim is to stabilize the epidemic at the disease-free equilibrium.The advantage of introduction of migration to the simple model validated the true R0 and the transmission rate b associated with HIV and AIDS epidemic disease in Malaysia.It also indicates an approximately 12 percentage points increase in the rate of HIV infection with migration.