-The model's physical equation is used to parameterize some subgrid-scale processes and physical processes in the present numerical model. The transmission and attenuation of the solar energy in the ocean are cons...-The model's physical equation is used to parameterize some subgrid-scale processes and physical processes in the present numerical model. The transmission and attenuation of the solar energy in the ocean are considered. A simple diagnostic equation for the cloud fractions k proposed on the basis of the humidities at the surface and the mid-troposphere. The parameterized formulae of both entrainment and Ekman pumping are improved.In the numerical integration, the treatment on damping the inertial oscillations is emphasized. The initialization and the objective analysis of the data which are necessary for the operational prediction will be presented in another paper.Results of SST prediction and some numerical experiments are given here. The model is computationally stable and successful in modelling the behaviors of the drift current and the mixed layer physics, and the AMD (absolute mean deviations) ≤1. 2℃ , RC (correlation coefficients ) ≥85% for 3-day forecasting.展开更多
This article deals with the problem of calculating the comparative uncertainty of the main variable in the model of the studied physical phenomenon, which depends on a qualitative and quantitative set of variables. Th...This article deals with the problem of calculating the comparative uncertainty of the main variable in the model of the studied physical phenomenon, which depends on a qualitative and quantitative set of variables. The choice of variables is determined by preliminary information available to the observer and dependent on his knowledge, experience and intuition. The finite value of the amount of information available to the researcher leads to the inevitable aberration of the observed object. This causes the existence of an unremovable and intractable processing by any statistical methods, a comparative (respectively, relative) uncertainty of the model. The goal is to present a theoretical justification for the existence of this uncertainty and proposes a procedure for its calculation. The practical application of the informational method for choosing the preferred model for the Einstein formula and for calculating the speed of sound is demonstrated.展开更多
By substituting rock skeleton modulus expressions into Gassmann approximate fluid equation, we obtain a seismic porosity inversion equation. However, conventional rock skeleton models and their expressions are quite d...By substituting rock skeleton modulus expressions into Gassmann approximate fluid equation, we obtain a seismic porosity inversion equation. However, conventional rock skeleton models and their expressions are quite different from each other, resuling in different seismic porosity inversion equations, potentially leading to difficulties in correctly applying them and evaluating their results. In response to this, a uniform relation with two adjusting parameters suitable for all rock skeleton models is established from an analysis and comparison of various conventional rock skeleton models and their expressions including the Eshelby-Walsh, Pride, Geertsma, Nur, Keys-Xu, and Krief models. By giving the two adjusting parameters specific values, different rock skeleton models with specific physical characteristics can be generated. This allows us to select the most appropriate rock skeleton model based on geological and geophysical conditions, and to develop more wise seismic porosity inversion. As an example of using this method for hydrocarbon prediction and fluid identification, we apply this improved porosity inversion, associated with rock physical data and well log data, to the ZJ basin. Research shows that the existence of an abundant hydrocarbon reservoir is dependent on a moderate porosity range, which means we can use the results of seismic porosity inversion to identify oil reservoirs and dry or water-saturated reservoirs. The seismic inversion results are closely correspond to well log porosity curves in the ZJ area, indicating that the uniform relations and inversion methods proposed in this paper are reliable and effective.展开更多
To further understand the status quo and change tendency of ecological security in county area, we took the example of Ningwu County, the headstream of Fenhe River, confronting serious eco-environment problem and cons...To further understand the status quo and change tendency of ecological security in county area, we took the example of Ningwu County, the headstream of Fenhe River, confronting serious eco-environment problem and considerable human impacts. Taking Ningwu as the study area and using variation coefficient method to determine the weights of the indices, we built ecological security pattern based on Pressure-State-Response （P-S-R） Model of Organization for Economic Cooperation and Development. The ecological security status was evaluated by calculating eco-security index （ESI） with socio-economic statistical data of Ningwu during 2001 -2010. The results showed that the situation of eco-security had been improved from heavy alarm to relative safety during 2001 -2010. It reflected that the ecological economic system in Ningwu County tended to be relaxed constantly after experienced a sharp conflict between ecological environment and economic growth. The ecological safety awareness was growing, however, by force of the objective requirements of population growth and economic development, the situation of ecological security was still unstable.展开更多
This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to pe...This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to perform the computations and gives the programs in details in R.展开更多
In the current work, we study two infectious disease models and we use nonlinear optimization and optimal control theory which helps to find strategies towards transmission control and to forecast the international sp...In the current work, we study two infectious disease models and we use nonlinear optimization and optimal control theory which helps to find strategies towards transmission control and to forecast the international spread of the infectious diseases. The relationship between epidemiology, mathematical modeling and computational tools lets us to build and test theories on the development and fighting with a disease. This study is motivated by the study of epidemiological models applied to infectious diseases in an optimal control perspective. We use the numerical methods to display the solutions of the optimal control problems to find the effect of vaccination on these models. Finally, global sensitivity analysis LHS Monte Carlo method using Partial Rank Correlation Coefficient (PRCC) has been performed to investigate the key parameters in model equations. This present work will advance the understanding about the spread of infectious diseases and lead to novel conceptual understanding for spread of them.展开更多
文摘-The model's physical equation is used to parameterize some subgrid-scale processes and physical processes in the present numerical model. The transmission and attenuation of the solar energy in the ocean are considered. A simple diagnostic equation for the cloud fractions k proposed on the basis of the humidities at the surface and the mid-troposphere. The parameterized formulae of both entrainment and Ekman pumping are improved.In the numerical integration, the treatment on damping the inertial oscillations is emphasized. The initialization and the objective analysis of the data which are necessary for the operational prediction will be presented in another paper.Results of SST prediction and some numerical experiments are given here. The model is computationally stable and successful in modelling the behaviors of the drift current and the mixed layer physics, and the AMD (absolute mean deviations) ≤1. 2℃ , RC (correlation coefficients ) ≥85% for 3-day forecasting.
文摘This article deals with the problem of calculating the comparative uncertainty of the main variable in the model of the studied physical phenomenon, which depends on a qualitative and quantitative set of variables. The choice of variables is determined by preliminary information available to the observer and dependent on his knowledge, experience and intuition. The finite value of the amount of information available to the researcher leads to the inevitable aberration of the observed object. This causes the existence of an unremovable and intractable processing by any statistical methods, a comparative (respectively, relative) uncertainty of the model. The goal is to present a theoretical justification for the existence of this uncertainty and proposes a procedure for its calculation. The practical application of the informational method for choosing the preferred model for the Einstein formula and for calculating the speed of sound is demonstrated.
基金supported by the National Nature Science Foundation of China(Grant No.41174114)Important National Science and Technology Specific Projects(Grant No.2011ZX05025-005-010)
文摘By substituting rock skeleton modulus expressions into Gassmann approximate fluid equation, we obtain a seismic porosity inversion equation. However, conventional rock skeleton models and their expressions are quite different from each other, resuling in different seismic porosity inversion equations, potentially leading to difficulties in correctly applying them and evaluating their results. In response to this, a uniform relation with two adjusting parameters suitable for all rock skeleton models is established from an analysis and comparison of various conventional rock skeleton models and their expressions including the Eshelby-Walsh, Pride, Geertsma, Nur, Keys-Xu, and Krief models. By giving the two adjusting parameters specific values, different rock skeleton models with specific physical characteristics can be generated. This allows us to select the most appropriate rock skeleton model based on geological and geophysical conditions, and to develop more wise seismic porosity inversion. As an example of using this method for hydrocarbon prediction and fluid identification, we apply this improved porosity inversion, associated with rock physical data and well log data, to the ZJ basin. Research shows that the existence of an abundant hydrocarbon reservoir is dependent on a moderate porosity range, which means we can use the results of seismic porosity inversion to identify oil reservoirs and dry or water-saturated reservoirs. The seismic inversion results are closely correspond to well log porosity curves in the ZJ area, indicating that the uniform relations and inversion methods proposed in this paper are reliable and effective.
基金Supported by National Natural Science Fund,China(41271143)Soft Science Research Project of Shanxi,China(2013041059-04)
文摘To further understand the status quo and change tendency of ecological security in county area, we took the example of Ningwu County, the headstream of Fenhe River, confronting serious eco-environment problem and considerable human impacts. Taking Ningwu as the study area and using variation coefficient method to determine the weights of the indices, we built ecological security pattern based on Pressure-State-Response （P-S-R） Model of Organization for Economic Cooperation and Development. The ecological security status was evaluated by calculating eco-security index （ESI） with socio-economic statistical data of Ningwu during 2001 -2010. The results showed that the situation of eco-security had been improved from heavy alarm to relative safety during 2001 -2010. It reflected that the ecological economic system in Ningwu County tended to be relaxed constantly after experienced a sharp conflict between ecological environment and economic growth. The ecological safety awareness was growing, however, by force of the objective requirements of population growth and economic development, the situation of ecological security was still unstable.
文摘This paper mainly talks about a popular approach of volatility of a GARCH-type model in R, while the disturbances are independent and have identical Student-t distribution. It uses the Metropolis-Hastings method to perform the computations and gives the programs in details in R.
文摘In the current work, we study two infectious disease models and we use nonlinear optimization and optimal control theory which helps to find strategies towards transmission control and to forecast the international spread of the infectious diseases. The relationship between epidemiology, mathematical modeling and computational tools lets us to build and test theories on the development and fighting with a disease. This study is motivated by the study of epidemiological models applied to infectious diseases in an optimal control perspective. We use the numerical methods to display the solutions of the optimal control problems to find the effect of vaccination on these models. Finally, global sensitivity analysis LHS Monte Carlo method using Partial Rank Correlation Coefficient (PRCC) has been performed to investigate the key parameters in model equations. This present work will advance the understanding about the spread of infectious diseases and lead to novel conceptual understanding for spread of them.
