RESUMO
Rock burst early warning technology is currently applied mainly in microseismic monitoring. Rock burst signals indicate the micro-fracture phenomena of a rock and can transmit earthquake waves through the rock before they are finally received by a detector. A characteristic decomposition of rock micro-fracture signals was conducted by the singular value Empirical Mode Decomposition (EMD) algorithm to effectively decompose the characteristic signals of a rock micro-fracture from mixed microseismic signals, with a low signal to noise ratio to ensure prediction precision. When comparing the proposed method with wavelet decomposition and EMD, it was found that the local characteristics of the signals were retained effectively. The proposed algorithm was verified by applying it in a laboratory simulation and to the decomposition of microseismic signals from a hydro-power station. It was concluded that the improved algorithm had a better decomposition precision than wavelet decomposition and EMD decomposition and could effectively separate the characteristic signals of micro-earthquakes. This could provide a significant basis for the identification of the abnormal microseismic signals of rock micro-fractures as well as a pre-warning of rock fractures. It is therefore of practical significance to study rock fracture early warning technology.
RESUMO
Objective To understand the epidemiology characteristics and survival status of HIV/AIDS patients with access to highly antiretroviral therapy (HAART) in Ningbo during 2004-2015.Methods A retrospective cohort study was conducted among HIV/AIDS patients diagnosed between 2004 and 2015.Life Tables were used to estimate survival rates,and Kaplan-Meier curve with Log rank test were used to describe the survival curves and the Cox proportional hazard model was used to determine predictors of mortality.Results Of the subjects,the median age when starting HAART was 35 years (IQR:27-45 years).Most of them were males,local residents,married,infected through heterosexual sexual transmission,and their baseline CD4 T cells counts were mainly ≤ 200 cells/μ 1,and most of them were at clinical stage Ⅰ (WHO).The cumulative survival rate was 96.75％ for the first year,92.36％ for the fifth year,91.87％ for the seventh year and 90.02％ for the tenth year.The risk of the mortality was 17.34 times higher for those aged ＞60 years compared with those aged ≤20 years (95％ CI:2.11-142.71),2.83 times higher for those at clinical stage ⅣV (WHO) compared with those at clinical stage Ⅰ (WHO) (95％CI:1.67-4.80) and 3.26 times higher for those with drug resistance compared with those without drug resistance (95％ CI:1.77-6.01).Blood transmission,lower CD4 + T cell level,BMI ＜ 18.5,unmarried were the risk factors for the mortality.Conclusions The effect of HAART was obvious in the HIV/AIDS patients in Ningbo,their survival rate was high.The finding indicated that it is necessary to strengthen the health care for old population and health education about AIDS prevention and control,and conduct large scale screening.Early discovery,early diagnosis,early treatment and improving treatment compliancy are still the effective ways to reduce the mortality.
RESUMO
Objective To understand the epidemiology characteristics and survival status of HIV/AIDS patients with access to highly antiretroviral therapy (HAART) in Ningbo during 2004-2015.Methods A retrospective cohort study was conducted among HIV/AIDS patients diagnosed between 2004 and 2015.Life Tables were used to estimate survival rates,and Kaplan-Meier curve with Log rank test were used to describe the survival curves and the Cox proportional hazard model was used to determine predictors of mortality.Results Of the subjects,the median age when starting HAART was 35 years (IQR:27-45 years).Most of them were males,local residents,married,infected through heterosexual sexual transmission,and their baseline CD4 T cells counts were mainly ≤ 200 cells/μ 1,and most of them were at clinical stage Ⅰ (WHO).The cumulative survival rate was 96.75％ for the first year,92.36％ for the fifth year,91.87％ for the seventh year and 90.02％ for the tenth year.The risk of the mortality was 17.34 times higher for those aged ＞60 years compared with those aged ≤20 years (95％ CI:2.11-142.71),2.83 times higher for those at clinical stage ⅣV (WHO) compared with those at clinical stage Ⅰ (WHO) (95％CI:1.67-4.80) and 3.26 times higher for those with drug resistance compared with those without drug resistance (95％ CI:1.77-6.01).Blood transmission,lower CD4 + T cell level,BMI ＜ 18.5,unmarried were the risk factors for the mortality.Conclusions The effect of HAART was obvious in the HIV/AIDS patients in Ningbo,their survival rate was high.The finding indicated that it is necessary to strengthen the health care for old population and health education about AIDS prevention and control,and conduct large scale screening.Early discovery,early diagnosis,early treatment and improving treatment compliancy are still the effective ways to reduce the mortality.
