目的了解中青年男男性行为者(men have sex with men,MSM)基于网络社交感染性传播疾病的高危行为及性关系网络特征。方法通过Blued(B组)、微信(V组)和线下场所(C组)招募MSM开展横断面问卷调查,分析各组MSM的高危行为及性关系网络异同点...目的了解中青年男男性行为者(men have sex with men,MSM)基于网络社交感染性传播疾病的高危行为及性关系网络特征。方法通过Blued(B组)、微信(V组)和线下场所(C组)招募MSM开展横断面问卷调查,分析各组MSM的高危行为及性关系网络异同点。结果共有197人(B、V、C组分别有85人、66人和46人)参加调查,年龄中位数(四分位数)M(P25,P75)为35(30,42)岁。三组对象年龄、文化程度、婚姻状态、职业、户籍差异均无统计学意义。过去6个月,B、V和C组男性性伴人数中位数(四分位数)分别是6(3,10)人、5(2,8)人和5(2,9)人(P>0.05);男性性行为人次数中位数(四分位数)分别是7(4,17)人次、6(3,13)人次和6(3,15)人次(P>0.05),坚持用安全套比例分别为38.8%、47.0%和30.4%(P>0.05);B、V和C组分别有95.2%、92.4%和89.1%的对象曾通过线上途径寻找性伴(P<0.05);B、V和C组各有45.9%、16.7%和26.1%的对象非常担心感染HIV(P<0.001),54.1%、75.8%和60.9%的对象在过去一年主动检测过HIV(P<0.05)。B、V和C组分别有44人、30人及23人报告性关系个体中心网络;各组应答者与未应答者相比,人口学及性行为等特征因素差异均无统计学意义。B、V和C组的平均网络密度分别为0.193、0.245、0.241。同为网络社交的B组和V组对象的性关系网络特征存在明显差异,其中V组对象网络特征与C组较为接近;B组平均相对入度、平均入接近中心度和平均中介中心度均低于V、C组对象,且平均相对出度、平均出接近中心度均高于V、C组对象。结论MSM表现为多性伴、安全套使用率较低等特点,不同的网络社交形成的MSM者性关系网络特征存在差异,需开展进一步研究。展开更多
A new type controller, fuzzy neural networks sliding mode controller (FNNSMC), is developed for a class of large scale systems with unknown bounds of high order interconnections and disturbances. Although sliding mod...A new type controller, fuzzy neural networks sliding mode controller (FNNSMC), is developed for a class of large scale systems with unknown bounds of high order interconnections and disturbances. Although sliding mode control is simple and insensitive to uncertainties and disturbances, there are two main problems in the sliding mode controller (SMC): control input chattering and the assumption of known bounds of uncertainties and disturbances. The FNNSMC, which incorporates the fuzzy neural networks (FNN) and the SMC, can eliminate the chattering by using the continuous output of the FNN to replace the discontinuous sign term in the SMC. The bounds of uncertainties and disturbances are also not required in the FNNSMC design. The simulation results show that the FNNSMC has more robustness than the SMC.展开更多
Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essent...Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essentially a linear correlation between response time and epicentral distance. Secondly, there was some correlation between maximum response amplitude and earthquake magnitude as well as between the duration and earthquake magnitude. Thirdly, the response amplitudes and decay rates were different for different types of instruments. Due to less data-sampling frequency, the deformation instruments, could not display the first motion of P and S waves, but responded mainly to far-field surface waves. Before the earthquake, the NS earthtide component recorded by the cave stainmeter at Yichang was distorted for nearly eight hours. While digital deformation observation did not show complete information about the earthquake source, it still reflected some key features of seismic-wave propagation.展开更多
The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors w...The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors were calculated by semi-empirical calculations. Models were established using partial least square(PLS) regression and back-propagation artificial neural network(BP-ANN). The QSPR results indicate that the descriptors of these derivatives have significant relationship with half-wave reduction potential. The stability and prediction ability of these models were validated using leave-one-out cross-validation and external test set.展开更多
Detailed soil surveys involve costly and time-consuming work and require expert knowledge. Since soil surveys provide information to meet a wide range of needs, new methods are necessary to map soils quickly and accur...Detailed soil surveys involve costly and time-consuming work and require expert knowledge. Since soil surveys provide information to meet a wide range of needs, new methods are necessary to map soils quickly and accurately. In this study, multilayer perceptron artificial neural networks(ANNs) were developed to map soil units using digital elevation model(DEM) attributes. Several optimal ANNs were produced based on a number of input data and hidden units. The approach used test and validation areas to calculate the accuracy of interpolated and extrapolated data. The results showed that the system and level of soil classification employed had a direct effect on the accuracy of the results. At the lowest level, smaller errors were observed with the World Reference Base(WRB)classification criteria than the Soil Taxonomy(ST) system, but more soil classes could be predicted when using ST(7 soils in the case of ST vs. 5 with WRB). Training errors were below 11% for all the ANN models applied, while the test error(interpolation error) and validation error(extrapolation error) were as high as 50% and 70%, respectively. As expected, soil prediction using a higher level of classification presented a better overall level of accuracy. To obtain better predictions, in addition to DEM attributes, data related to landforms and/or lithology as soil-forming factors, should be used as ANN input data.展开更多
文摘目的了解中青年男男性行为者(men have sex with men,MSM)基于网络社交感染性传播疾病的高危行为及性关系网络特征。方法通过Blued(B组)、微信(V组)和线下场所(C组)招募MSM开展横断面问卷调查,分析各组MSM的高危行为及性关系网络异同点。结果共有197人(B、V、C组分别有85人、66人和46人)参加调查,年龄中位数(四分位数)M(P25,P75)为35(30,42)岁。三组对象年龄、文化程度、婚姻状态、职业、户籍差异均无统计学意义。过去6个月,B、V和C组男性性伴人数中位数(四分位数)分别是6(3,10)人、5(2,8)人和5(2,9)人(P>0.05);男性性行为人次数中位数(四分位数)分别是7(4,17)人次、6(3,13)人次和6(3,15)人次(P>0.05),坚持用安全套比例分别为38.8%、47.0%和30.4%(P>0.05);B、V和C组分别有95.2%、92.4%和89.1%的对象曾通过线上途径寻找性伴(P<0.05);B、V和C组各有45.9%、16.7%和26.1%的对象非常担心感染HIV(P<0.001),54.1%、75.8%和60.9%的对象在过去一年主动检测过HIV(P<0.05)。B、V和C组分别有44人、30人及23人报告性关系个体中心网络;各组应答者与未应答者相比,人口学及性行为等特征因素差异均无统计学意义。B、V和C组的平均网络密度分别为0.193、0.245、0.241。同为网络社交的B组和V组对象的性关系网络特征存在明显差异,其中V组对象网络特征与C组较为接近;B组平均相对入度、平均入接近中心度和平均中介中心度均低于V、C组对象,且平均相对出度、平均出接近中心度均高于V、C组对象。结论MSM表现为多性伴、安全套使用率较低等特点,不同的网络社交形成的MSM者性关系网络特征存在差异,需开展进一步研究。
文摘A new type controller, fuzzy neural networks sliding mode controller (FNNSMC), is developed for a class of large scale systems with unknown bounds of high order interconnections and disturbances. Although sliding mode control is simple and insensitive to uncertainties and disturbances, there are two main problems in the sliding mode controller (SMC): control input chattering and the assumption of known bounds of uncertainties and disturbances. The FNNSMC, which incorporates the fuzzy neural networks (FNN) and the SMC, can eliminate the chattering by using the continuous output of the FNN to replace the discontinuous sign term in the SMC. The bounds of uncertainties and disturbances are also not required in the FNNSMC design. The simulation results show that the FNNSMC has more robustness than the SMC.
文摘Tih and strain meters of the deformation-observation network in Hubei Province all responded to the Mw9.0 Japan earthquake on March 11,2011. By analyzing the co-seismic responses,we found that firstly there was essentially a linear correlation between response time and epicentral distance. Secondly, there was some correlation between maximum response amplitude and earthquake magnitude as well as between the duration and earthquake magnitude. Thirdly, the response amplitudes and decay rates were different for different types of instruments. Due to less data-sampling frequency, the deformation instruments, could not display the first motion of P and S waves, but responded mainly to far-field surface waves. Before the earthquake, the NS earthtide component recorded by the cave stainmeter at Yichang was distorted for nearly eight hours. While digital deformation observation did not show complete information about the earthquake source, it still reflected some key features of seismic-wave propagation.
基金Project supported by the Postdoctoral Science Foundation of Central South University,ChinaProject(2015SK20823)supported by Science and Technology Project of Hunan Province,China+2 种基金Project(15A001)supported by Scientific Research Fund of Hunan Provincial Education Department,ChinaProject(CX2015B372)supported by Hunan Provincial Innovation Foundation for Postgraduate,ChinaProject supported by Innovation Experiment Program for University Students of Changsha University of Science and Technology,China
文摘The quantitative structure-property relationship(QSPR) of anabolic androgenic steroids was studied on the half-wave reduction potential(E1/2) using quantum and physico-chemical molecular descriptors. The descriptors were calculated by semi-empirical calculations. Models were established using partial least square(PLS) regression and back-propagation artificial neural network(BP-ANN). The QSPR results indicate that the descriptors of these derivatives have significant relationship with half-wave reduction potential. The stability and prediction ability of these models were validated using leave-one-out cross-validation and external test set.
文摘Detailed soil surveys involve costly and time-consuming work and require expert knowledge. Since soil surveys provide information to meet a wide range of needs, new methods are necessary to map soils quickly and accurately. In this study, multilayer perceptron artificial neural networks(ANNs) were developed to map soil units using digital elevation model(DEM) attributes. Several optimal ANNs were produced based on a number of input data and hidden units. The approach used test and validation areas to calculate the accuracy of interpolated and extrapolated data. The results showed that the system and level of soil classification employed had a direct effect on the accuracy of the results. At the lowest level, smaller errors were observed with the World Reference Base(WRB)classification criteria than the Soil Taxonomy(ST) system, but more soil classes could be predicted when using ST(7 soils in the case of ST vs. 5 with WRB). Training errors were below 11% for all the ANN models applied, while the test error(interpolation error) and validation error(extrapolation error) were as high as 50% and 70%, respectively. As expected, soil prediction using a higher level of classification presented a better overall level of accuracy. To obtain better predictions, in addition to DEM attributes, data related to landforms and/or lithology as soil-forming factors, should be used as ANN input data.