Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected...Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected. Based on the compre-hensive analysis of main factors and induced factors, the standard for risk grades of this disease was promoted and northeast region of China was divided into 4 districts with different risk grades: seriously occurring district, commonly occurring district, occasionally occurring district, and un-occurring district. Nonlinear regression analysis for six model curves showed that the Richard growth model was suitable for describing the temporal dynamics of poplar INA bacterial canker. By stepwise variable selection method, the multi-variable linear regression forecasting equation was set up to predict the next year抯 disease index, and the GM (1,1) model was also set up by grey method to submit middle or long period forecast.展开更多
Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the re...Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the retweeting behavior is desirable for a number of tasks such as topic detection, personalized message recommendation, and fake information monitoring and prevention. Interestingly, the propagation of tweets bears some similarity to the spread of infectious diseases. We present a method to model the tweets' spread behavior in microblogs based on the classic Susceptible-Infectious-Susceptible (SIS) epidemic model that was developed in the medical field for the spread of infectious diseases. On the basis of this model, future retweeting trends can be predicted. Our experiments on data obtained from the Chinese micro-blogging website Sina Weibo show that the proposed model has lower predictive error compared to the four commonly used prediction methods.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
基金National Foundation of Ninth Five-Year Plan (No. 96-005-04-01-03).
文摘Through the methods of correlation analysis and main factor analysis, the relationship between the poplar INA bacte-rial canker and circumstances was analyzed and 9 main factors for affecting the disease were selected. Based on the compre-hensive analysis of main factors and induced factors, the standard for risk grades of this disease was promoted and northeast region of China was divided into 4 districts with different risk grades: seriously occurring district, commonly occurring district, occasionally occurring district, and un-occurring district. Nonlinear regression analysis for six model curves showed that the Richard growth model was suitable for describing the temporal dynamics of poplar INA bacterial canker. By stepwise variable selection method, the multi-variable linear regression forecasting equation was set up to predict the next year抯 disease index, and the GM (1,1) model was also set up by grey method to submit middle or long period forecast.
基金supported by National Natural Science Foundation of China under Grants No. 60773156, No. 61073004Chinese Major State Basic Research Development 973 Program under Grant No. 2011CB302203-2Important National Science &Technology Specific Program under Grant No. 2011ZX01042001-002-2
文摘Microblogs currently play an important role in social communication. Hot topics currently being tweeted can quickly become popular within a very short time as a result of retweeting. Gaining an understanding of the retweeting behavior is desirable for a number of tasks such as topic detection, personalized message recommendation, and fake information monitoring and prevention. Interestingly, the propagation of tweets bears some similarity to the spread of infectious diseases. We present a method to model the tweets' spread behavior in microblogs based on the classic Susceptible-Infectious-Susceptible (SIS) epidemic model that was developed in the medical field for the spread of infectious diseases. On the basis of this model, future retweeting trends can be predicted. Our experiments on data obtained from the Chinese micro-blogging website Sina Weibo show that the proposed model has lower predictive error compared to the four commonly used prediction methods.
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.
