We study numerical methods for level set like equations arising in image processing and curve evolution problems. Semi-implicit finite volume-element type schemes are constructed for the general level set like equati...We study numerical methods for level set like equations arising in image processing and curve evolution problems. Semi-implicit finite volume-element type schemes are constructed for the general level set like equation （image selective smoothing model） given by Alvarez et al. （Alvarez L, Lions P L, Morel J M. Image selective smoothing and edge detection by nonlinear diffusion II. SIAM J. Numer. Anal., 1992, 29： 845-866）. Through the reasonable semi-implicit discretization in time and co-volume method for space approximation, we give finite volume schemes, unconditionally stable in L∞ and W1＇2 （W1＇1） sense in isotropic （anisotropic） diffu- sion domain.展开更多
针对CTCS-3级列控系统在无线消息超时降级至CTCS-2级运行时速度差异较大的问题,提出在后备模式下将CTCS-2顶棚速度由300 k m/h调整为350 k m/h,并将国内高铁线路坡度情况分为3类,经过分析线路坡度、制动距离等因素,提出将轨道电路信息...针对CTCS-3级列控系统在无线消息超时降级至CTCS-2级运行时速度差异较大的问题,提出在后备模式下将CTCS-2顶棚速度由300 k m/h调整为350 k m/h,并将国内高铁线路坡度情况分为3类,经过分析线路坡度、制动距离等因素,提出将轨道电路信息码最高扩展至L9码。相关设备需按此方案进行修改。该技术可实现CTCS-3级列控系统在350 km/h等速降级为CTCS-2级的冗余切换,覆盖国内所有既有350 k m/h等级高铁。通过以上技术改进,能够最大限度降低对运行时分的影响,充分发挥CTCS-2级后备系统的作用。展开更多
The technological scheme of a hard rock surface mine is a multiple level production system of interdependently func-tioning elements. Selection of the optimum combination of its elements constitutes a complex multiple...The technological scheme of a hard rock surface mine is a multiple level production system of interdependently func-tioning elements. Selection of the optimum combination of its elements constitutes a complex multiple variant and criteria problem of decision making. In this paper describes the theoretical part of the method proposed for the quantitative analysis and selection of the most competent technological schemes, based on the mathematical formulations of the selection criteria of the element of each level as functions of the alternative variants of the elements of the level and its adjacent levels. It is realized in accordance to standard procedures of decision making in the formation of the economical mathematical model of the cumulative influence of levels and elements on the effectiveness of all alternative variants in their analysis and generation of a small subset of the most competent variants, which are subjected to further analysis using the criterion of reliability in the generation of the optimum technological scheme. The scientific challenge inherent in its realization constitutes a PhD research opportunity for those interested in the problems of optimization in hard rock surface mines.展开更多
The paper first describes the characteristics of the new rural pension scheme and then analyzes some problems emergingin its implementation based on afield in Anhui province’s Dangtu County and Jiangsu province’s Ho...The paper first describes the characteristics of the new rural pension scheme and then analyzes some problems emergingin its implementation based on afield in Anhui province’s Dangtu County and Jiangsu province’s Hongze County inApril 2010.Unlike the urban pension system, the new rural pension scheme is of a voluntary nature, and unlike the oldrural pension scheme, the government subsidizes participants using fiscal revenue.However, in its implementation thereare some problems.The first involves the so-called "bundle scheme" that requires pensioners’ children to participate.Evidence from our field study shows that coverage is less than 80%, even with a "bundle scheme." On the country,the "bundle scheme" increases social costs and it should therefore be replaced with legal regulations.Next, the paperexplains why a majority of participants choose the minimum contribution level based on observations in the fieldstudy.This choice reflects the two-fold information asymmetry between the authority and rural residents.Based onthe field study, we suggest that the new rural pension authority listen to village cadres and farmers to increase farmers’awareness.展开更多
基金Acknowledgments The authors wish to thank the HuBei Natural Science Foundation under Grant NO.2007ABA376 and Hubei Education Foundation under Grant NO.D200717005 under which the present work was possible.
文摘We study numerical methods for level set like equations arising in image processing and curve evolution problems. Semi-implicit finite volume-element type schemes are constructed for the general level set like equation （image selective smoothing model） given by Alvarez et al. （Alvarez L, Lions P L, Morel J M. Image selective smoothing and edge detection by nonlinear diffusion II. SIAM J. Numer. Anal., 1992, 29： 845-866）. Through the reasonable semi-implicit discretization in time and co-volume method for space approximation, we give finite volume schemes, unconditionally stable in L∞ and W1＇2 （W1＇1） sense in isotropic （anisotropic） diffu- sion domain.
文摘针对CTCS-3级列控系统在无线消息超时降级至CTCS-2级运行时速度差异较大的问题,提出在后备模式下将CTCS-2顶棚速度由300 k m/h调整为350 k m/h,并将国内高铁线路坡度情况分为3类,经过分析线路坡度、制动距离等因素,提出将轨道电路信息码最高扩展至L9码。相关设备需按此方案进行修改。该技术可实现CTCS-3级列控系统在350 km/h等速降级为CTCS-2级的冗余切换,覆盖国内所有既有350 k m/h等级高铁。通过以上技术改进,能够最大限度降低对运行时分的影响,充分发挥CTCS-2级后备系统的作用。
文摘The technological scheme of a hard rock surface mine is a multiple level production system of interdependently func-tioning elements. Selection of the optimum combination of its elements constitutes a complex multiple variant and criteria problem of decision making. In this paper describes the theoretical part of the method proposed for the quantitative analysis and selection of the most competent technological schemes, based on the mathematical formulations of the selection criteria of the element of each level as functions of the alternative variants of the elements of the level and its adjacent levels. It is realized in accordance to standard procedures of decision making in the formation of the economical mathematical model of the cumulative influence of levels and elements on the effectiveness of all alternative variants in their analysis and generation of a small subset of the most competent variants, which are subjected to further analysis using the criterion of reliability in the generation of the optimum technological scheme. The scientific challenge inherent in its realization constitutes a PhD research opportunity for those interested in the problems of optimization in hard rock surface mines.
文摘The paper first describes the characteristics of the new rural pension scheme and then analyzes some problems emergingin its implementation based on afield in Anhui province’s Dangtu County and Jiangsu province’s Hongze County inApril 2010.Unlike the urban pension system, the new rural pension scheme is of a voluntary nature, and unlike the oldrural pension scheme, the government subsidizes participants using fiscal revenue.However, in its implementation thereare some problems.The first involves the so-called "bundle scheme" that requires pensioners’ children to participate.Evidence from our field study shows that coverage is less than 80%, even with a "bundle scheme." On the country,the "bundle scheme" increases social costs and it should therefore be replaced with legal regulations.Next, the paperexplains why a majority of participants choose the minimum contribution level based on observations in the fieldstudy.This choice reflects the two-fold information asymmetry between the authority and rural residents.Based onthe field study, we suggest that the new rural pension authority listen to village cadres and farmers to increase farmers’awareness.
