With the utilization of underground space,backward erosion piping(BEP)has been observed in many underground structures(e.g.,shield tunnels)founded on sandy aquifers.However,due to invisibility,the geometry of the erod...With the utilization of underground space,backward erosion piping(BEP)has been observed in many underground structures(e.g.,shield tunnels)founded on sandy aquifers.However,due to invisibility,the geometry of the eroded pipe and its spatial evolution with time during the piping process was still not clear.In this study,we developed a Hele-Shaw cell to visualize the dynamic progression of BEP.With imaging process technology,we obtained a typical process of BEP(the erosion process can be divided into a piping progression phase and a piping stabilization phase),quantitatively characterized the formation of erosion pipes,and compared the patterns of erosion(e.g.,the erosion area A and the maximum erosion radius R)that spontaneously develop under different fluxes of water.The most interesting finding is that the sand grains in a thicker Hele-Shaw model are easier to dislodge,which is possibly due to the granular system in a thicker model having more degrees of freedom,reducing the stability of the sand grains.展开更多
It is possible to say that each of the Mexican and Turkish automotive industries is developed as an assembly industry and shows great similarities to each other within this framework.However,due to its geographical pr...It is possible to say that each of the Mexican and Turkish automotive industries is developed as an assembly industry and shows great similarities to each other within this framework.However,due to its geographical proximity,the role of US-based automotive companies in the formation of the Mexican automotive industry has become greater,while the Ford Motor company,which entered the US automotive industry in Turkey,was able to take part only with the initiatives of the Otosan company in the 1960s.Another feature of the 1960s is that there were efforts to manufacture domestic cars in Turkey.Since the 1980s,in line with the direction of development of the world automotive industry,Turkey has been trying to make the country’s investment environment attractive for foreign international companies to produce in their countries.In Mexico,even with the possibility of reaching new markets by providing 1990 regional agreements NAFTA ruling party of the Mexican automotive industry,we can say that U.S.firms were largely determined by the direction of development,Turkey’s automotive industry development direction of the company is determined by the first European,then we can say that companies are becoming more efficient in the Far East countries.On the other hand,the US Ford Motor company considered it sufficient to be involved in the Turkey directly.Turkey has decided to return from the policy of attracting foreign investments to its country since 2006,and in 2011 it was decided to produce domestic cars.As of December 2019,a prototype of a domestic car has been produced by the Automobile Enterprise Group of Turkey and work has begun on mass production.Thus,the problem of adaptation to the production of electric vehicles was decided to be overcome by moving to a new stage on the way to technology development.This approach was used by the South Korean automotive industry in the 1980s and was successful,and the ability to develop technology was acquired in a short time.In order to see the success of the application of this 展开更多
The development of Backward Stochastic Differential Equation Theory is just a thing happened in the past years. Although its development and application is far behind Forward Stochastic Differential Equation, its wide...The development of Backward Stochastic Differential Equation Theory is just a thing happened in the past years. Although its development and application is far behind Forward Stochastic Differential Equation, its wide application prospect on financial mathematics gets more and more attention. The meaning of Backward Stochastic Differential Equation is that change a already-known final （usually uncertain） goal into a present certain answer to make a present resolution. But Insurance Pricing happens to know the final result, it＇ s certain that the result is uncertain, that is to say, to get out of danger or not. And then make present insurance price according to the future uncertain result. The Insurance Pricing just follows the meaning of Backward Stochastic Differential Equation. Insurance Pricing itself is also a research field sprang up in past scores of years, because insurance pricing is the indisputable core of insurance work, and gets quite a few researchers＇ attention. This article adopts backward stochastic differential equation theory and do research on problem about technology insurance pricing.展开更多
基金the National Engineering Laboratory for Digital Construction and Evaluation Technology of Urban Rail Transit(No.2021GY01)the National Natural Science Foundation of China(No.41630641)。
文摘With the utilization of underground space,backward erosion piping(BEP)has been observed in many underground structures(e.g.,shield tunnels)founded on sandy aquifers.However,due to invisibility,the geometry of the eroded pipe and its spatial evolution with time during the piping process was still not clear.In this study,we developed a Hele-Shaw cell to visualize the dynamic progression of BEP.With imaging process technology,we obtained a typical process of BEP(the erosion process can be divided into a piping progression phase and a piping stabilization phase),quantitatively characterized the formation of erosion pipes,and compared the patterns of erosion(e.g.,the erosion area A and the maximum erosion radius R)that spontaneously develop under different fluxes of water.The most interesting finding is that the sand grains in a thicker Hele-Shaw model are easier to dislodge,which is possibly due to the granular system in a thicker model having more degrees of freedom,reducing the stability of the sand grains.
文摘It is possible to say that each of the Mexican and Turkish automotive industries is developed as an assembly industry and shows great similarities to each other within this framework.However,due to its geographical proximity,the role of US-based automotive companies in the formation of the Mexican automotive industry has become greater,while the Ford Motor company,which entered the US automotive industry in Turkey,was able to take part only with the initiatives of the Otosan company in the 1960s.Another feature of the 1960s is that there were efforts to manufacture domestic cars in Turkey.Since the 1980s,in line with the direction of development of the world automotive industry,Turkey has been trying to make the country’s investment environment attractive for foreign international companies to produce in their countries.In Mexico,even with the possibility of reaching new markets by providing 1990 regional agreements NAFTA ruling party of the Mexican automotive industry,we can say that U.S.firms were largely determined by the direction of development,Turkey’s automotive industry development direction of the company is determined by the first European,then we can say that companies are becoming more efficient in the Far East countries.On the other hand,the US Ford Motor company considered it sufficient to be involved in the Turkey directly.Turkey has decided to return from the policy of attracting foreign investments to its country since 2006,and in 2011 it was decided to produce domestic cars.As of December 2019,a prototype of a domestic car has been produced by the Automobile Enterprise Group of Turkey and work has begun on mass production.Thus,the problem of adaptation to the production of electric vehicles was decided to be overcome by moving to a new stage on the way to technology development.This approach was used by the South Korean automotive industry in the 1980s and was successful,and the ability to develop technology was acquired in a short time.In order to see the success of the application of this
文摘The development of Backward Stochastic Differential Equation Theory is just a thing happened in the past years. Although its development and application is far behind Forward Stochastic Differential Equation, its wide application prospect on financial mathematics gets more and more attention. The meaning of Backward Stochastic Differential Equation is that change a already-known final （usually uncertain） goal into a present certain answer to make a present resolution. But Insurance Pricing happens to know the final result, it＇ s certain that the result is uncertain, that is to say, to get out of danger or not. And then make present insurance price according to the future uncertain result. The Insurance Pricing just follows the meaning of Backward Stochastic Differential Equation. Insurance Pricing itself is also a research field sprang up in past scores of years, because insurance pricing is the indisputable core of insurance work, and gets quite a few researchers＇ attention. This article adopts backward stochastic differential equation theory and do research on problem about technology insurance pricing.
