In this paper,the vibration signals in the fatigue crack growth process in a chinese steel used in a mining machinery were analyzed by the frequency spectrum, the time series and grey system model,and the critical cri...In this paper,the vibration signals in the fatigue crack growth process in a chinese steel used in a mining machinery were analyzed by the frequency spectrum, the time series and grey system model,and the critical criterion for crack initiation was proposed.展开更多
Three forecasting models are set up: the auto\|regressive moving average model, the grey forecasting model for the rate of qualified products P t, and the grey forecasting model for time intervals of the quality cata...Three forecasting models are set up: the auto\|regressive moving average model, the grey forecasting model for the rate of qualified products P t, and the grey forecasting model for time intervals of the quality catastrophes. Then a combined forewarning system for the quality of products is established, which contains three models, judgment rules and forewarning state illustration. Finally with an example of the practical production, this modeling system is proved fairly effective.展开更多
This paper presents a method of foretelling populations in Beijing in any year and in the future through the grey system model. At the same time a process table of calculation on population is given
AIM To investigate the incidence and mortality rates of upper gastrointestinal cancer(UGIC) in Hebei Province, China, and to identify high-risk populations to improve UGIC prevention and control.METHODS Data for UGIC ...AIM To investigate the incidence and mortality rates of upper gastrointestinal cancer(UGIC) in Hebei Province, China, and to identify high-risk populations to improve UGIC prevention and control.METHODS Data for UGIC patients were collected from 21 population-based cancer registries covering 15.25% of the population in Hebei Province. Mortality data were extracted from three national retrospective death surveys(1973-1975, 1990-1992 and 2004-2005). The data were stratified by 5-year age groups, gender and area(high-risk/non-high-risk areas) for analysis. The age-period-cohort and grey system model were used.RESULTS The crude incidence rate of UGIC was 55.47/100000, and the adjusted rate(Segi's population) was 44.90/100000. Males in rural areas had the highest incidence rate(world age-standardized rate = 87.89/100000). The crude mortality rate of UGIC displayed a decreasing trend in Hebei Province from the 1970 s to 2013, and the adjusted rate decreased by 43.81% from the 1970s(58.07/100000) to 2013(32.63/100000). The mortality rate declined more significantly in the high-risk areas(57.26%) than in the non-high-risk areas(55.02%) from the 1970 s to 2013. The median age at diagnosis of UGIC was 65.06 years in 2013. There was a notable delay in the median age at death from the 1970s(66.15 years) to 2013(70.39 years), especially in the high-risk areas. In Cixian, the total trend of the cohort effect declined, and people aged 65-69 years were a population at relatively high risk for UGIC. We predicted that the crude mortality rates of UGIC in Cixian and Shexian would decrease to 98.80 and 133.99 per 100000 in 2018, respectively.CONCLUSION UGIC was the major cause of cancer death in Hebei Province, and males in rural areas were a high-risk population. We should strengthen early detection and treatment of UGIC in this population.展开更多
文摘In this paper,the vibration signals in the fatigue crack growth process in a chinese steel used in a mining machinery were analyzed by the frequency spectrum, the time series and grey system model,and the critical criterion for crack initiation was proposed.
文摘Three forecasting models are set up: the auto\|regressive moving average model, the grey forecasting model for the rate of qualified products P t, and the grey forecasting model for time intervals of the quality catastrophes. Then a combined forewarning system for the quality of products is established, which contains three models, judgment rules and forewarning state illustration. Finally with an example of the practical production, this modeling system is proved fairly effective.
文摘This paper presents a method of foretelling populations in Beijing in any year and in the future through the grey system model. At the same time a process table of calculation on population is given
文摘AIM To investigate the incidence and mortality rates of upper gastrointestinal cancer(UGIC) in Hebei Province, China, and to identify high-risk populations to improve UGIC prevention and control.METHODS Data for UGIC patients were collected from 21 population-based cancer registries covering 15.25% of the population in Hebei Province. Mortality data were extracted from three national retrospective death surveys(1973-1975, 1990-1992 and 2004-2005). The data were stratified by 5-year age groups, gender and area(high-risk/non-high-risk areas) for analysis. The age-period-cohort and grey system model were used.RESULTS The crude incidence rate of UGIC was 55.47/100000, and the adjusted rate(Segi's population) was 44.90/100000. Males in rural areas had the highest incidence rate(world age-standardized rate = 87.89/100000). The crude mortality rate of UGIC displayed a decreasing trend in Hebei Province from the 1970 s to 2013, and the adjusted rate decreased by 43.81% from the 1970s(58.07/100000) to 2013(32.63/100000). The mortality rate declined more significantly in the high-risk areas(57.26%) than in the non-high-risk areas(55.02%) from the 1970 s to 2013. The median age at diagnosis of UGIC was 65.06 years in 2013. There was a notable delay in the median age at death from the 1970s(66.15 years) to 2013(70.39 years), especially in the high-risk areas. In Cixian, the total trend of the cohort effect declined, and people aged 65-69 years were a population at relatively high risk for UGIC. We predicted that the crude mortality rates of UGIC in Cixian and Shexian would decrease to 98.80 and 133.99 per 100000 in 2018, respectively.CONCLUSION UGIC was the major cause of cancer death in Hebei Province, and males in rural areas were a high-risk population. We should strengthen early detection and treatment of UGIC in this population.
