To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,...To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,which is then fed into downstream learning modules.Co-SFM employs an upstream fusion module to incorporate multilevel data,thereby constructing a macro-plate-micro data structure.This configuration helps identify and integrate characteristics from different data levels,facilitating a deeper understanding of the internal links within the financial system.In the downstream model,Co-SFM uses a state-frequency memory network to mine hidden frequency information within stock prices,and the multifrequency patterns of sequential data are modeled.Empirical results show that Co-SFM s prediction accuracy for stock price trends is significantly better than that of other models.This is especially evident in multistep medium and long-term trend predictions,where integrating multilevel data results in notably improved accuracy.展开更多
The application of ti me-series modeling and forecasting method to the spectral analysis for lubricat ing oil of mechanical equipment is discussed. The AR model is used to perform a time-series modeling and forecasti...The application of ti me-series modeling and forecasting method to the spectral analysis for lubricat ing oil of mechanical equipment is discussed. The AR model is used to perform a time-series modeling and forecasting analysis for the spectral analysis data co llected from aero-engines. In the oil condition monitoring field of mechanical equipment, the use of the method of time-series analysis has rarely been report ed. As indicated in the satisfactory example, a practical method for condition m onitoring and fault forecasting of mechanical equipment has been achieved.展开更多
In this paper, the characteristics of thunderstorms in Zibo City were ana- lyzed. The thunderstorms could be divided into cold-front thunderstorm, upper trough (shear line) type thunderstorm and cold-vortex thunders...In this paper, the characteristics of thunderstorms in Zibo City were ana- lyzed. The thunderstorms could be divided into cold-front thunderstorm, upper trough (shear line) type thunderstorm and cold-vortex thunderstorm. We also screened out the atmosphere parameters that were highly correlated to the occurrence of thunder/ lightning. They were treated as the predictors. Each possible influencing factor was analyzed on the lightning day correspondingly. Their threshold values were also de- termined. Among them, the parameter that had the highest neutralizing capacity was treated as negative index. For different type of thunderstorm weather, the negative index was different. The application of negative indexes was also discussed. We hope to provide a valuable basis for the accurate forecasting of thunder/lightning.展开更多
The application of bio-inspired computational techniques to the field of condition monitoring is addressed. First, the bio-inspired computational techniques are briefly addressed; the advantages and disadvantages of t...The application of bio-inspired computational techniques to the field of condition monitoring is addressed. First, the bio-inspired computational techniques are briefly addressed; the advantages and disadvantages of these computational methods are made clear. Then, the roles of condition monitoring in the predictive maintenance and failures prediction and the development trends of condition monitoring are discussed. Finally, a case study on the condition monitoring of grinding machine is described, which shows the application of bio-inspired computational technique to a practical condition monitoring system.展开更多
Ten upland cotton strains exhibiting 3 fiber quality traits and 8 yield traits, were grown for two years in an investigation of the correlation between grey relational analysis (GRA) and genetic identity in heterosi...Ten upland cotton strains exhibiting 3 fiber quality traits and 8 yield traits, were grown for two years in an investigation of the correlation between grey relational analysis (GRA) and genetic identity in heterosis of cot- ton hybrid. The aim was to establish the optimal approach for heterosis prediction and parent selection. Plant traits data were collected and analyzed for GRA. In addition, 72 simple sequence repeat (SSR) markers were examined and 148 polymorphisms were detected. Correlation analysis of GRA, genetic identity, Ft fiber quality and yield heterosis was conducted. Significant differences were observed between the two analytic methods, whereas compa- rable predictions were given for yield heterosis. GRA for yield exhibited slightly higher correlation than genetic identity analysis, with a correlation coefficient of 0.49. GRA and genetic analysis exhibited overlapping yet dis- tinct advantages in heterosis prediction. Therefore, these analytical methods should be integrated to achieve the op- timal heterosis prediction and parent selection.展开更多
The Longyangxia Gorge Key Water Control System is the first of the stairstep power sations along the Longyangxi-a-Qingtongxia river section. It has been playing an very important role in providing power, protecting fl...The Longyangxia Gorge Key Water Control System is the first of the stairstep power sations along the Longyangxi-a-Qingtongxia river section. It has been playing an very important role in providing power, protecting flood and ice run supplying and irrigation etc. in the northwestern China. Therefore, the study on trend prediction, variation on the flow into the Longyangxia Reservoir are of the great social and economic benefits. In the medium-and-long-range runoff forecast, all kinds of regression equation are often used for predicting future hydrologic regime. However, these regression models aren’t appropriate to super long -range runoff forecast because of the restricting on weather data and so on. So a new super long-range runoff forecast model don’t depend on Reai-time weather data and called “Period correcting for residual error series GM (1, 1) model” is presented based on analyzing for the relational hydrologic data and the variation on the flow into the Longyangxia Reservoir, and the forecast model was applied successfully to predict the recent and super long -term trends of the flow into the Longyangxia Reservoir. The results indicate that the annual flow into the Longyangxia Reservoir is in the ending minimum period of the runoff history. The runoff increasing is expected in for the coming years.展开更多
Taking Shenzhen city as an example, the statistical and physical relationship between the density of pollutants and various atmospheric parameters are analyzed in detail, and a space-partitioned city air pollution pot...Taking Shenzhen city as an example, the statistical and physical relationship between the density of pollutants and various atmospheric parameters are analyzed in detail, and a space-partitioned city air pollution potential prediction scheme is established based on it. The scheme considers quantitatively more than ten factors at the surface and planetary boundary layer (PBL), especially the effects of anisotropy of geographical environment, and treats wind direction as an independent impact factor. While the scheme treats the prediction equation respectively for different pollutants according to their differences in dilute properties, it considers as well the possible differences in dilute properties at different districts of the city under the same atmospheric condition, treating predictions respectively for different districts. Finally, the temporally and spatially high resolution predictions for the atmospheric factors are made with a high resolution numerical model, and further the space-partitioned and time-variational city pollution potential predictions are made. The scheme is objective and quantitative, and with clear physical meaning, so it is suitable to use in making high resolution air pollution predictions.展开更多
In this study, surface air temperature from 75 meteorological stations above 3000 m on the Tibetan Plateau are applied for evaluation of the European Centre for Medium-Range Weather Forecasts(ECMWF) third-generation r...In this study, surface air temperature from 75 meteorological stations above 3000 m on the Tibetan Plateau are applied for evaluation of the European Centre for Medium-Range Weather Forecasts(ECMWF) third-generation reanalysis product ERA-Interim in the period of 1979-2010. High correlations ranging from 0.973 to 0.999 indicate that ERA-Interim could capture the annual cycle very well. However, an average root-meansquare error(rmse) of 3.7°C for all stations reveals that ERA-Interim could not be applied directly for the individual sites. The biases can be mainly attributed to the altitude differences between ERA-Interim grid points and stations. An elevation correction method based on monthly lapse rates is limited to reduce the bias for all stations. Generally, ERA-Interim captured the Plateau-Wide annual and seasonal climatologies very well. The spatial variance is highly related to the topographic features of the TP. The temperature increases significantly(10°C- 15°C) from the western to the eastern Tibetan Plateau for all seasons, in particular during winter and summer. A significant warming trend(0.49°C/decade) is found over the entire Tibetan Plateau using station time series from 1979-2010. ERA-Interim captures the annual warming trend with an increase rate of 0.33°C /decade very well. The observation data and ERA-Interim data both showed the largest warming trends in winter with values of 0.67°C/decade and 0.41°C/decade, respectively. We conclude that in general ERA-Interim captures the temperature trends very well and ERA-Interim is reliable for climate change investigation over the Tibetan Plateau under the premise of cautious interpretation.展开更多
This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40...This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.展开更多
Objective: Male breast cancer is a rare disease with an incidence of about 1% of breast cancers in USA, but relatively lack of the information of male breast cancer in China, especially in Southwest of China, led us t...Objective: Male breast cancer is a rare disease with an incidence of about 1% of breast cancers in USA, but relatively lack of the information of male breast cancer in China, especially in Southwest of China, led us to study its incidence trends. Methods: Chongqing is one of the biggest and the most important areas that is located in Southwest of China. There are around 31.4 million people who live in approximate 82 402.95 km2area of Chongqing. Data about breast cancer patients registered in the Center for Disease Prevention and Control of Chongqing(China) were statistically collected from 187 hospitals, about 58 hospitals in city and 129 hospitals in country, and over 6.2 million people were studied every year. It was tried to represent all the people in villages and cities in Chongqing, China. Results: The incidence of male breast cancer in Southwest of China ranged from 0.34/100 000 to 1.45/100 000 between 2007 and 2011, while the incidence of female breast cancer ranged from 15.40/100000 to 21.66/100000 at the same time. The rate of male breast cancer to female breast cancer ranged from 0.02:1 to 0.07:1, male breast cancer accounted for 1.96% to 6.5%(with the mean value of 2.9%) of breast cancers in Southwest of China from 2007 to 2010. Conclusion: In Southwest of China male breast cancer accounts for about 2.9% of breast cancers which is higher than that in United States. It is important for policy makers and health manager to seriously consider breast cancer in future plan in Southwest of China.展开更多
A potential energy framework for assessment of grid vulnerability was presented.In the framework,the branch potential energy function model was constructed.Two indexes,current vulnerability and forecasting vulnerabili...A potential energy framework for assessment of grid vulnerability was presented.In the framework,the branch potential energy function model was constructed.Two indexes,current vulnerability and forecasting vulnerability,were calculated.The current vulnerability was used to identify the current vulnerable area through calculating the distance between the current transmitted power and initial transmitted power;and the forecast vulnerability under variation of power injection was used to predict the vulnerable area of next step and verify the current vulnerable area.Numerical simulation was performed under variant operating conditions with IEEE-30 bus system,which shows that almost area of 90% overlaps between current vulnerable area and forecasting vulnerable area,the overlapped area is termed as inherent vulnerable area of grid.When considering N-1 contingency,the assessment results of this method proposed agree with those of optimal power flow.When considering N-2 contingency,optimal power flow fails to obtain correct results,while the method based on energy framework gives reliable results.展开更多
From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order ...From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order to review the overall situation and provide information on major accidents of coal mines in China, we investigated 26 major coal mining accidents in China between the years of 1949 and 2009 through statistical methods, each of which led to more than 100 fatalities. Statistical characteristics about accident-related factors such as time, death toll, accident reasons, characters and nature of enterprise were analyzed. And some special conclusions have been achieved. For example, although we have made great progress, the safety situation in China coal mining industry is still serious, and the reasons for the mining accidents are all human errors which are not inevitable. Such results may be helpful to prevent major accidents in coal mines. Moreso, based on both the knowledge of other countries which have good safety situation nowadays and the safety management situation of China, we made suggestion on safety management of China coal mining. In conclusion, countermeasures were proposed in accordance with the results of statistical studies and the analyses of problems existed in coal mines, including the perfec- tion of safety supervision organization, the establishment of cooperating agency among government, coal mines and workers, the perfection of safety rules and regulations, the improvement of safety investment, the enhancement of safety training, the development of safety technique, and the development of emer- gency rescue technique and equipment.展开更多
With the development and popularization of network technology, such as attacks from the network is also facing serious challenges, showing a "one foot in mind that" the situation. How can detect possible security ri...With the development and popularization of network technology, such as attacks from the network is also facing serious challenges, showing a "one foot in mind that" the situation. How can detect possible security risks and the type of attack, and provide preventive strategy is to network managers have been pursuing the goal of network security situational awareness can speak a variety of services and associated data as a highly organic whole, summarized network security and dependency relationships come more comprehensive, complete, accurate decision-making for network security assessment and countermeasures.展开更多
In this paper, we provide several methods to solve the problem of humanoid robot walking on rough terrains. By using the Passive Inverted Pendulum Model(PIPM) and predictive control, with some optimizing strategy ad...In this paper, we provide several methods to solve the problem of humanoid robot walking on rough terrains. By using the Passive Inverted Pendulum Model(PIPM) and predictive control, with some optimizing strategy added, we realized the smooth walking on a slope with rocks on it.展开更多
Objective:To make a summary of the trends of HIV/AIDS epidemic and route of transmission in Shenzhen from 1992 to 2000 to provide scientific evidence for the policy-maker to formulate strategies of HIV/AIDS prevention...Objective:To make a summary of the trends of HIV/AIDS epidemic and route of transmission in Shenzhen from 1992 to 2000 to provide scientific evidence for the policy-maker to formulate strategies of HIV/AIDS prevention and control in Shenzhen.Method:To analyze HIV/AIDS surveillance data in Shenzhen from 1992 to 2000 by software Epi-Info. Results: One hundred and two HIV positive cases including 18 AIDS cases (three cases deceased) were identified in Shenzhen from 1992 to 2000. Among the 102 cases, those infected via sex were 46.0%, intravenous drug use 42.9%.Blood donation 7.8%, blood transfusion recipient 3.9%, and indeterminate 2%. Conclusion: In Shenzhen, HIV/AIDS infection is spreading and increasing rapidly. Effective prevention measures must be taken to reduce the HIV prevalence as soon as possible.展开更多
This paper presents a game-theoretic method to predict microgrid(MG) development tendency in China. As many distribution generators(DGs) are integrated in distribution systems, analysis of MG formation necessity is co...This paper presents a game-theoretic method to predict microgrid(MG) development tendency in China. As many distribution generators(DGs) are integrated in distribution systems, analysis of MG formation necessity is conducted from the aspect of DGs. In order to maximize the profit brought by DGs and to earn money from arbitrage, it may be necessary for customers to combine their DGs and loads and to construct an MG to obtain maximal control ability. A game model is built to emulate trading between MGs and the distribution system based on MG power control, in which both trading profit and outage cost are considered for each MG. Nash equilibrium(NE) is calculated, and sensitivities of NE to some boundary conditions are studied. The results show that variable MG trading prices with appropriate net generation cost(i.e., DG generation cost minus government subsidy price) may encourage the growth of MGs. Government subsidies, generation costs, and trading prices may also affect DG use, and therefore they may impact customer motivation to build MGs.展开更多
基金The National Natural Science Foundation of China(No.72173018).
文摘To systematically incorporate multiple influencing factors,the coupled-state frequency memory(Co-SFM)network is proposed.This model integrates Copula estimation with neural networks,fusing multilevel data information,which is then fed into downstream learning modules.Co-SFM employs an upstream fusion module to incorporate multilevel data,thereby constructing a macro-plate-micro data structure.This configuration helps identify and integrate characteristics from different data levels,facilitating a deeper understanding of the internal links within the financial system.In the downstream model,Co-SFM uses a state-frequency memory network to mine hidden frequency information within stock prices,and the multifrequency patterns of sequential data are modeled.Empirical results show that Co-SFM s prediction accuracy for stock price trends is significantly better than that of other models.This is especially evident in multistep medium and long-term trend predictions,where integrating multilevel data results in notably improved accuracy.
文摘The application of ti me-series modeling and forecasting method to the spectral analysis for lubricat ing oil of mechanical equipment is discussed. The AR model is used to perform a time-series modeling and forecasting analysis for the spectral analysis data co llected from aero-engines. In the oil condition monitoring field of mechanical equipment, the use of the method of time-series analysis has rarely been report ed. As indicated in the satisfactory example, a practical method for condition m onitoring and fault forecasting of mechanical equipment has been achieved.
文摘In this paper, the characteristics of thunderstorms in Zibo City were ana- lyzed. The thunderstorms could be divided into cold-front thunderstorm, upper trough (shear line) type thunderstorm and cold-vortex thunderstorm. We also screened out the atmosphere parameters that were highly correlated to the occurrence of thunder/ lightning. They were treated as the predictors. Each possible influencing factor was analyzed on the lightning day correspondingly. Their threshold values were also de- termined. Among them, the parameter that had the highest neutralizing capacity was treated as negative index. For different type of thunderstorm weather, the negative index was different. The application of negative indexes was also discussed. We hope to provide a valuable basis for the accurate forecasting of thunder/lightning.
基金supported by the National Natural Science Foundation of China ( No. 61025019No. 90820016)+1 种基金Program for New Century Excellent Talents in University ( No. NECT-07-0735)Natural Science Foundation of Hebei ( No. F2009001638)
文摘The application of bio-inspired computational techniques to the field of condition monitoring is addressed. First, the bio-inspired computational techniques are briefly addressed; the advantages and disadvantages of these computational methods are made clear. Then, the roles of condition monitoring in the predictive maintenance and failures prediction and the development trends of condition monitoring are discussed. Finally, a case study on the condition monitoring of grinding machine is described, which shows the application of bio-inspired computational technique to a practical condition monitoring system.
基金Hi-tech Research and Development Program of China(No.2012AA101108-02)National Science and Technology Pillar Program(No.2011BAD35B05)Modern Agro-industry Technology Research System(No.CARS-18-05)
文摘Ten upland cotton strains exhibiting 3 fiber quality traits and 8 yield traits, were grown for two years in an investigation of the correlation between grey relational analysis (GRA) and genetic identity in heterosis of cot- ton hybrid. The aim was to establish the optimal approach for heterosis prediction and parent selection. Plant traits data were collected and analyzed for GRA. In addition, 72 simple sequence repeat (SSR) markers were examined and 148 polymorphisms were detected. Correlation analysis of GRA, genetic identity, Ft fiber quality and yield heterosis was conducted. Significant differences were observed between the two analytic methods, whereas compa- rable predictions were given for yield heterosis. GRA for yield exhibited slightly higher correlation than genetic identity analysis, with a correlation coefficient of 0.49. GRA and genetic analysis exhibited overlapping yet dis- tinct advantages in heterosis prediction. Therefore, these analytical methods should be integrated to achieve the op- timal heterosis prediction and parent selection.
基金Ninth-Five-Year"Key Project of the State Science and Technology Commission (96-912-01-02-05 ) and National NaturalScience Fou
文摘The Longyangxia Gorge Key Water Control System is the first of the stairstep power sations along the Longyangxi-a-Qingtongxia river section. It has been playing an very important role in providing power, protecting flood and ice run supplying and irrigation etc. in the northwestern China. Therefore, the study on trend prediction, variation on the flow into the Longyangxia Reservoir are of the great social and economic benefits. In the medium-and-long-range runoff forecast, all kinds of regression equation are often used for predicting future hydrologic regime. However, these regression models aren’t appropriate to super long -range runoff forecast because of the restricting on weather data and so on. So a new super long-range runoff forecast model don’t depend on Reai-time weather data and called “Period correcting for residual error series GM (1, 1) model” is presented based on analyzing for the relational hydrologic data and the variation on the flow into the Longyangxia Reservoir, and the forecast model was applied successfully to predict the recent and super long -term trends of the flow into the Longyangxia Reservoir. The results indicate that the annual flow into the Longyangxia Reservoir is in the ending minimum period of the runoff history. The runoff increasing is expected in for the coming years.
文摘Taking Shenzhen city as an example, the statistical and physical relationship between the density of pollutants and various atmospheric parameters are analyzed in detail, and a space-partitioned city air pollution potential prediction scheme is established based on it. The scheme considers quantitatively more than ten factors at the surface and planetary boundary layer (PBL), especially the effects of anisotropy of geographical environment, and treats wind direction as an independent impact factor. While the scheme treats the prediction equation respectively for different pollutants according to their differences in dilute properties, it considers as well the possible differences in dilute properties at different districts of the city under the same atmospheric condition, treating predictions respectively for different districts. Finally, the temporally and spatially high resolution predictions for the atmospheric factors are made with a high resolution numerical model, and further the space-partitioned and time-variational city pollution potential predictions are made. The scheme is objective and quantitative, and with clear physical meaning, so it is suitable to use in making high resolution air pollution predictions.
基金funded by Fujian Bureau of Surveying,Mapping and Geoinformation(Grant No.2013S17)Natural Science Foundation of China(Grant No.71373130)+2 种基金Non-Profit Research Projects of Fujian Province,China(Grant No2013R04)Key Project of the Department of Science and Technology of Fujian Province,China(Grant No.2012Y4001)supported by the ECMWF’s public web server(http://apps.ecmwf.int/datasets/)
文摘In this study, surface air temperature from 75 meteorological stations above 3000 m on the Tibetan Plateau are applied for evaluation of the European Centre for Medium-Range Weather Forecasts(ECMWF) third-generation reanalysis product ERA-Interim in the period of 1979-2010. High correlations ranging from 0.973 to 0.999 indicate that ERA-Interim could capture the annual cycle very well. However, an average root-meansquare error(rmse) of 3.7°C for all stations reveals that ERA-Interim could not be applied directly for the individual sites. The biases can be mainly attributed to the altitude differences between ERA-Interim grid points and stations. An elevation correction method based on monthly lapse rates is limited to reduce the bias for all stations. Generally, ERA-Interim captured the Plateau-Wide annual and seasonal climatologies very well. The spatial variance is highly related to the topographic features of the TP. The temperature increases significantly(10°C- 15°C) from the western to the eastern Tibetan Plateau for all seasons, in particular during winter and summer. A significant warming trend(0.49°C/decade) is found over the entire Tibetan Plateau using station time series from 1979-2010. ERA-Interim captures the annual warming trend with an increase rate of 0.33°C /decade very well. The observation data and ERA-Interim data both showed the largest warming trends in winter with values of 0.67°C/decade and 0.41°C/decade, respectively. We conclude that in general ERA-Interim captures the temperature trends very well and ERA-Interim is reliable for climate change investigation over the Tibetan Plateau under the premise of cautious interpretation.
基金supported by the National Ky Basic Research Development Program(Grant Nos.2015CB453200,2013CB956200,2012CB957803,2010CB950400)the National Natural Science Foundation of China(Grant Nos.41430426,41490642,41275086,41475070)
文摘This paper presents the long-term climate changes of significant wave height(Hs) in 1958–2001 over the entire global ocean using the 45-year European Centre for Medium-Range Weather Forecasts(ECMWF) Reanalysis(ERA-40) wave data. The linear trends in Hs and regional and seasonal differences of the linear trends for Hs were calculated. Results show that the Hs exhibits a significant increasing trend of about 4.6 cm decade-1 in the global ocean as a whole over the last 44 years. The Hs changes slowly during the periods 1958–1974 and 1980–1991, while it increases consistently during the periods 1975–1980 and 1995–1998. The Hs reaches its lowest magnitude in 1975, with annual average wave height about 2 m. In 1992, the Hs has the maximum value of nearly 2.60 m. The Hs in most ocean waters has a significant increasing trend of 2–14 cm decade-1 over the last 44 years. The linear trend exhibits great regional differences. Areas with strong increasing trend of Hs are mainly distributed in the westerlies of the southern Hemisphere and the northern Hemisphere. Only some small areas show obvious decreasing in Hs. The long-term trend of Hs in DJF(December, January, February) and MAM(March, April, May) is much more stronger than that in JJA(June, July, August) and SON(September, October, November). The linear trends of the Hs in different areas are different in different seasons; for instance, the increasing trend of Hs in the westerlies of the Pacific Ocean mainly appears in MAM and DJF.
文摘Objective: Male breast cancer is a rare disease with an incidence of about 1% of breast cancers in USA, but relatively lack of the information of male breast cancer in China, especially in Southwest of China, led us to study its incidence trends. Methods: Chongqing is one of the biggest and the most important areas that is located in Southwest of China. There are around 31.4 million people who live in approximate 82 402.95 km2area of Chongqing. Data about breast cancer patients registered in the Center for Disease Prevention and Control of Chongqing(China) were statistically collected from 187 hospitals, about 58 hospitals in city and 129 hospitals in country, and over 6.2 million people were studied every year. It was tried to represent all the people in villages and cities in Chongqing, China. Results: The incidence of male breast cancer in Southwest of China ranged from 0.34/100 000 to 1.45/100 000 between 2007 and 2011, while the incidence of female breast cancer ranged from 15.40/100000 to 21.66/100000 at the same time. The rate of male breast cancer to female breast cancer ranged from 0.02:1 to 0.07:1, male breast cancer accounted for 1.96% to 6.5%(with the mean value of 2.9%) of breast cancers in Southwest of China from 2007 to 2010. Conclusion: In Southwest of China male breast cancer accounts for about 2.9% of breast cancers which is higher than that in United States. It is important for policy makers and health manager to seriously consider breast cancer in future plan in Southwest of China.
基金Project(51007006) supported by the National Natural Science Foundation of ChinaProject(20090185120023) supported by the Ph.D Programs Foundation for New Teacher of Ministry of Education of China
文摘A potential energy framework for assessment of grid vulnerability was presented.In the framework,the branch potential energy function model was constructed.Two indexes,current vulnerability and forecasting vulnerability,were calculated.The current vulnerability was used to identify the current vulnerable area through calculating the distance between the current transmitted power and initial transmitted power;and the forecast vulnerability under variation of power injection was used to predict the vulnerable area of next step and verify the current vulnerable area.Numerical simulation was performed under variant operating conditions with IEEE-30 bus system,which shows that almost area of 90% overlaps between current vulnerable area and forecasting vulnerable area,the overlapped area is termed as inherent vulnerable area of grid.When considering N-1 contingency,the assessment results of this method proposed agree with those of optimal power flow.When considering N-2 contingency,optimal power flow fails to obtain correct results,while the method based on energy framework gives reliable results.
基金support from the Science and Technology Programming Project of Shandong Provincein China (No. 2010GSF10808)the National Natural Science Foundation of China (No. 51074100)
文摘From the year of 1949 to the present, the China national coal output has been increasing quickly and became first in the world in 2009. But at the same time, major coal mining accidents still exist nowadays. In order to review the overall situation and provide information on major accidents of coal mines in China, we investigated 26 major coal mining accidents in China between the years of 1949 and 2009 through statistical methods, each of which led to more than 100 fatalities. Statistical characteristics about accident-related factors such as time, death toll, accident reasons, characters and nature of enterprise were analyzed. And some special conclusions have been achieved. For example, although we have made great progress, the safety situation in China coal mining industry is still serious, and the reasons for the mining accidents are all human errors which are not inevitable. Such results may be helpful to prevent major accidents in coal mines. Moreso, based on both the knowledge of other countries which have good safety situation nowadays and the safety management situation of China, we made suggestion on safety management of China coal mining. In conclusion, countermeasures were proposed in accordance with the results of statistical studies and the analyses of problems existed in coal mines, including the perfec- tion of safety supervision organization, the establishment of cooperating agency among government, coal mines and workers, the perfection of safety rules and regulations, the improvement of safety investment, the enhancement of safety training, the development of safety technique, and the development of emer- gency rescue technique and equipment.
文摘With the development and popularization of network technology, such as attacks from the network is also facing serious challenges, showing a "one foot in mind that" the situation. How can detect possible security risks and the type of attack, and provide preventive strategy is to network managers have been pursuing the goal of network security situational awareness can speak a variety of services and associated data as a highly organic whole, summarized network security and dependency relationships come more comprehensive, complete, accurate decision-making for network security assessment and countermeasures.
文摘In this paper, we provide several methods to solve the problem of humanoid robot walking on rough terrains. By using the Passive Inverted Pendulum Model(PIPM) and predictive control, with some optimizing strategy added, we realized the smooth walking on a slope with rocks on it.
文摘Objective:To make a summary of the trends of HIV/AIDS epidemic and route of transmission in Shenzhen from 1992 to 2000 to provide scientific evidence for the policy-maker to formulate strategies of HIV/AIDS prevention and control in Shenzhen.Method:To analyze HIV/AIDS surveillance data in Shenzhen from 1992 to 2000 by software Epi-Info. Results: One hundred and two HIV positive cases including 18 AIDS cases (three cases deceased) were identified in Shenzhen from 1992 to 2000. Among the 102 cases, those infected via sex were 46.0%, intravenous drug use 42.9%.Blood donation 7.8%, blood transfusion recipient 3.9%, and indeterminate 2%. Conclusion: In Shenzhen, HIV/AIDS infection is spreading and increasing rapidly. Effective prevention measures must be taken to reduce the HIV prevalence as soon as possible.
基金supported by the National Natural Science Foundation of China(Grant No.51321005)the National Hi-Tech Research and Development Program of China("863"Project)(Grant No.2012AA050217)
文摘This paper presents a game-theoretic method to predict microgrid(MG) development tendency in China. As many distribution generators(DGs) are integrated in distribution systems, analysis of MG formation necessity is conducted from the aspect of DGs. In order to maximize the profit brought by DGs and to earn money from arbitrage, it may be necessary for customers to combine their DGs and loads and to construct an MG to obtain maximal control ability. A game model is built to emulate trading between MGs and the distribution system based on MG power control, in which both trading profit and outage cost are considered for each MG. Nash equilibrium(NE) is calculated, and sensitivities of NE to some boundary conditions are studied. The results show that variable MG trading prices with appropriate net generation cost(i.e., DG generation cost minus government subsidy price) may encourage the growth of MGs. Government subsidies, generation costs, and trading prices may also affect DG use, and therefore they may impact customer motivation to build MGs.