随着人工智能在医疗领域的融合,基于影像学仪器与可穿戴设备的智能辅助系统不断发展,推动疾病早期诊断成为可能。脑小血管病(Cerebral Small Vessel Disease,CSVD)作为常见老年性脑血管疾病,起病隐匿、进展缓慢,严重影响生活质量。然而...随着人工智能在医疗领域的融合,基于影像学仪器与可穿戴设备的智能辅助系统不断发展,推动疾病早期诊断成为可能。脑小血管病(Cerebral Small Vessel Disease,CSVD)作为常见老年性脑血管疾病,起病隐匿、进展缓慢,严重影响生活质量。然而,其数据获取困难且类别不平衡,为智能预测模型构建带来挑战。文中基于机器学习技术,围绕脑小血管病智能预测开展研究。首先,进行了关键危险因素筛选;然后,采用SMOTE-Tomek Links方法对不平衡数据进行处理;最后,进行了脑小血管病精准危险预测模型构建,并通过五折交叉验证对模型的性能进行了验证。实验结果表明:所提方法在小样本不平衡环境下,能够显著提升准确率、召回率和接受者操作特征曲线下面积(Area Under Curve,AUC)值,为脑小血管病的早期预测与诊断提供了一种有效方案。展开更多
Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has b...Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has been one of the most popular topics in development of dairy industry in China. Compared with the countries with developed dairy industry worldwide, dairy industry in China is featured by not high informationization level and backward modernization level at the present stage. However, development and maturity of related technologies for pasture informatization construction provides a significant opportunity for transformation and upgrading and leaping development of dairy industry in China.展开更多
Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineeri...Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.展开更多
文摘随着人工智能在医疗领域的融合,基于影像学仪器与可穿戴设备的智能辅助系统不断发展,推动疾病早期诊断成为可能。脑小血管病(Cerebral Small Vessel Disease,CSVD)作为常见老年性脑血管疾病,起病隐匿、进展缓慢,严重影响生活质量。然而,其数据获取困难且类别不平衡,为智能预测模型构建带来挑战。文中基于机器学习技术,围绕脑小血管病智能预测开展研究。首先,进行了关键危险因素筛选;然后,采用SMOTE-Tomek Links方法对不平衡数据进行处理;最后,进行了脑小血管病精准危险预测模型构建,并通过五折交叉验证对模型的性能进行了验证。实验结果表明:所提方法在小样本不平衡环境下,能够显著提升准确率、召回率和接受者操作特征曲线下面积(Area Under Curve,AUC)值,为脑小血管病的早期预测与诊断提供了一种有效方案。
基金Supported by Open Science and Technology Cooperation Project of Henan Province(162106000017)Science and Technology Project Benefiting People in Henan Province(152207110004)Key Science and Technology Research Project of Puyang City(150109)
文摘Dairy industry is an indispensable component of modem agriculture. How to improve informatization level and technology content of dairy industry and progress informationalization construction process of pastures has been one of the most popular topics in development of dairy industry in China. Compared with the countries with developed dairy industry worldwide, dairy industry in China is featured by not high informationization level and backward modernization level at the present stage. However, development and maturity of related technologies for pasture informatization construction provides a significant opportunity for transformation and upgrading and leaping development of dairy industry in China.
基金supported by the National Key Research and Development Program of China (Grant No. 2021YFC2203600)National Natural Science Foundation of China (Grant Nos. 52005377 and 51975447)+1 种基金Youth Innovation Team of Shaanxi Universities (Grant No. 201926)Fundamental Research Funds for the Central Universities (Grant Nos. JB210404 and JB210403)。
文摘Large reflector antennas are widely used as radio telescopes and active main reflectors are generally applied to improve the surface accuracy. Considering that the high cost has been one important problem in engineering, it is worth discussing whether it is necessary to install actuators on all the panels. Thus, in this paper, a hybrid-panel-based new design idea for large reflector antenna is proposed. Assuming that the actuators are installed only in the region of the reflector with large deformations and there are no actuators in other region to reduce the actuator number, the surface accuracies and the corresponding electromagnetic(EM) performances calculated by three different panel adjustment strategies are compared. The most effective method is that the deformed reflector should be first preadjusted to reduce the gravity deformation and then the panels equipped with actuators should be adjusted to the locations determined by the best fitting reflector(BFR) derived by the deformed reflector with no actuators. A 35 m reflector antenna is adopted as an example to calculate the surface accuracy and EM performance when parts of the panels are equipped with actuators. The simulation results show that there is no need to install actuators on all panels and the presented method can greatly reduce the number of actuators with guaranteed surface accuracy. Thus, during the antenna structural design phase, once the surface accuracy requirement is given, the number of actuators can be minimized to reduce the manufacturing and maintenance costs as much as possible. This paper can provide valuable guidance for the design of an active main reflector with hybrid panels.
