In this note,one kind of insurance risk models with the policies having multiple validity times are investigated.Explicit expressions for the ruin probabilities are obtained by using the martingale method.As a consequ...In this note,one kind of insurance risk models with the policies having multiple validity times are investigated.Explicit expressions for the ruin probabilities are obtained by using the martingale method.As a consequence,the obtained probability serves as an upper bound for the ruin probability of a newly developed entrance processes based risk model.展开更多
Based on the deformation characteristics of the roadways driven along goaf in fully mechanized top coal caving faces, the author considers that it is the key to ensure the stability of surrounding rocks of roadway dri...Based on the deformation characteristics of the roadways driven along goaf in fully mechanized top coal caving faces, the author considers that it is the key to ensure the stability of surrounding rocks of roadway driven along goaf to control the deformation during the period affected by mining. Considering the characteristics of the roadway layout in fully mechanized top coal caving faces, a technical scheme of destressing is put forward and the destressing effect is analyzed by using the software of Universal Distinct Element Code 3 0(UDEC 3 0).展开更多
Sustainable economic growth has put Indonesia as a middle-income country （MIC） and currently, the level of per capita income has already exceeded US$3,000. The increase in income per capita is followed by the increa...Sustainable economic growth has put Indonesia as a middle-income country （MIC） and currently, the level of per capita income has already exceeded US$3,000. The increase in income per capita is followed by the increasing number of middle-class population and the reduction in poverty. However, it has not been accompanied by declining inequality that reflects the quality of economic growth. According to Kuznets theory, an increase in inequality is a common problem in the process of economic growth. Inequality will further decline after the country has reached a certain threshold level of income. This study aims to analyze the trend and nature of income inequality in Indonesia and to test whether the Kuznets Curve holds. This paper used dynamic panel method with 26 provincial panel data from 2000 to 2011. The empirical result proves the existence of inverted U-shaped Kuznets Curve in Indonesia and it may have the turning points when the real GDP per capita in each province reached Rp. 179.41 million/year or around US$17.000. For the determinant of inequality in Indonesia, this study found that the percentage of urban population, inflation, and share of agricultural sector contributed to the increase of inequality, while high-level education and share of industrial sector are associated with the lower level of inequality.展开更多
Traits that aid in the invasion process should exhibit a gradient across the expansion range in response to changing selection pressures. Aggression has been repeatedly associated with invasion success in many taxa, a...Traits that aid in the invasion process should exhibit a gradient across the expansion range in response to changing selection pressures. Aggression has been repeatedly associated with invasion success in many taxa, as it may help invaders to wrestle the resources from other species which enhances their success in a novel environment. However, aggression primarily al lows individuals to overcome conspecific rivals, providing advantages in competition over resources. Agonistic prowess could therefore increase fitness at both ends of the expansion gradient. Here we review the role of aggression in range expansion of in vasive species, and its potential role as a driver of range expansion. We analyze how these different mechanisms could affect trait variation in expanding and invasive populations. Specifically, we look at how aggression could help dilate the edges of a popula tion through niche competition, as well as lead to exclusion from the center （Le. areas of high population density） by the conspe cities. Both of these processes will result in a characteristic spatial distribution of phenotypes related to aggression that could provide insights into the ecological pressures and dynamics of expanding populations, potentially providing clues to their success as niche competitors and invasive species展开更多
基金Supported by the Grant to Supervisors of Postgraduates with Universities in Gansu Province(1001-10)
文摘In this note,one kind of insurance risk models with the policies having multiple validity times are investigated.Explicit expressions for the ruin probabilities are obtained by using the martingale method.As a consequence,the obtained probability serves as an upper bound for the ruin probability of a newly developed entrance processes based risk model.
文摘Based on the deformation characteristics of the roadways driven along goaf in fully mechanized top coal caving faces, the author considers that it is the key to ensure the stability of surrounding rocks of roadway driven along goaf to control the deformation during the period affected by mining. Considering the characteristics of the roadway layout in fully mechanized top coal caving faces, a technical scheme of destressing is put forward and the destressing effect is analyzed by using the software of Universal Distinct Element Code 3 0(UDEC 3 0).
文摘Sustainable economic growth has put Indonesia as a middle-income country （MIC） and currently, the level of per capita income has already exceeded US$3,000. The increase in income per capita is followed by the increasing number of middle-class population and the reduction in poverty. However, it has not been accompanied by declining inequality that reflects the quality of economic growth. According to Kuznets theory, an increase in inequality is a common problem in the process of economic growth. Inequality will further decline after the country has reached a certain threshold level of income. This study aims to analyze the trend and nature of income inequality in Indonesia and to test whether the Kuznets Curve holds. This paper used dynamic panel method with 26 provincial panel data from 2000 to 2011. The empirical result proves the existence of inverted U-shaped Kuznets Curve in Indonesia and it may have the turning points when the real GDP per capita in each province reached Rp. 179.41 million/year or around US$17.000. For the determinant of inequality in Indonesia, this study found that the percentage of urban population, inflation, and share of agricultural sector contributed to the increase of inequality, while high-level education and share of industrial sector are associated with the lower level of inequality.
文摘Traits that aid in the invasion process should exhibit a gradient across the expansion range in response to changing selection pressures. Aggression has been repeatedly associated with invasion success in many taxa, as it may help invaders to wrestle the resources from other species which enhances their success in a novel environment. However, aggression primarily al lows individuals to overcome conspecific rivals, providing advantages in competition over resources. Agonistic prowess could therefore increase fitness at both ends of the expansion gradient. Here we review the role of aggression in range expansion of in vasive species, and its potential role as a driver of range expansion. We analyze how these different mechanisms could affect trait variation in expanding and invasive populations. Specifically, we look at how aggression could help dilate the edges of a popula tion through niche competition, as well as lead to exclusion from the center （Le. areas of high population density） by the conspe cities. Both of these processes will result in a characteristic spatial distribution of phenotypes related to aggression that could provide insights into the ecological pressures and dynamics of expanding populations, potentially providing clues to their success as niche competitors and invasive species
