水果作为我国种植业中第四大农作物类别,在国民经济中占据着十分重要的地位,水果的价格波动不仅影响居民生活成本,也影响果农的收入。因此,预判水果价格的走势十分重要。文中选取2021年第22周至2024年第38周,共计174周的红富士苹果、巨...水果作为我国种植业中第四大农作物类别,在国民经济中占据着十分重要的地位,水果的价格波动不仅影响居民生活成本,也影响果农的收入。因此,预判水果价格的走势十分重要。文中选取2021年第22周至2024年第38周,共计174周的红富士苹果、巨峰葡萄和麒麟西瓜这三种水果的周度批发价格数据,建立VMD-SSA-LSTM模型,并与LSTM、VMD-LSTM模型的水果价格预测效果进行对比,实验发现,VMD-SSA-LSTM模型的预测值最接近真实值,且其RMSE、MAE、MAPE的数值均小于LSTM、VMD-LSTM模型的数值,表明VMD-SSA-LSTM模型的预测效果优于LSTM、VMD-LSTM模型。Fruits are the fourth largest crop category in China’s agricultural sector and play a vital role in the national economy. The fluctuations in fruit prices not only affect the cost of living for residents but also affect the income of fruit farmers. Therefore, it is crucial to forecast the trend of fruit prices. In this study, we selected the weekly wholesale prices of Red Fuji apples, Jufeng grapes, and Qilin watermelons from week 22 of 2021 to week 38 of 2024, a total of 174 weeks, and built the VMD-SSA-LSTM model to predict the prices of these three fruits. We also compared the fruit price prediction effects of the VMD-SSA-LSTM model with those of the LSTM and VMD-LSTM models. The experimental results show that the predicted values of the VMD-SSA-LSTM model are closest to the actual values, and its RMSE, MAE, and MAPE values are all smaller than those of the LSTM and VMD-LSTM models, indicating that the prediction effect of the VMD-SSA-LSTM model is better than that of the LSTM and VMD-LSTM models.展开更多
获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Spa...获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Space-based Solar Observatory,ASO-S)卫星的载荷之一,莱曼阿尔法太阳望远镜(Lyman-alpha Solar Telescope,LST),包括3台科学仪器,具体来说是由一个双波段太阳日冕仪(Solar Corona Imager,SCI)以及白光太阳望远镜(White-light Solar Telescope,WST)和莱曼阿尔法全日面太阳成像仪(Solar Disk Imager,SDI)这两个全日面太阳望远镜构成.WST和SDI的探测器是互补金属氧化物半导体(Complementary Metal-Oxide-Semiconductor,CMOS),其平场本身的主要特征是由于激光退火造成的条纹结构,当CMOS探测器在紫外波段使用时会产生一定的衰减与辐射损伤,并且探测器上的水汽凝结和有机物的积累等污染,也会对所得平场产生一定影响.主要展示了ASO-S卫星发射两年多来,载荷LST的两个仪器WST和SDI在轨平场定标时使用的偏摆方案及其优化以及获得的平场图像和其随时间的演化情况等,并简要地介绍了WST和SDI探测器随时间的衰减和辐射损伤情况.展开更多
文摘水果作为我国种植业中第四大农作物类别,在国民经济中占据着十分重要的地位,水果的价格波动不仅影响居民生活成本,也影响果农的收入。因此,预判水果价格的走势十分重要。文中选取2021年第22周至2024年第38周,共计174周的红富士苹果、巨峰葡萄和麒麟西瓜这三种水果的周度批发价格数据,建立VMD-SSA-LSTM模型,并与LSTM、VMD-LSTM模型的水果价格预测效果进行对比,实验发现,VMD-SSA-LSTM模型的预测值最接近真实值,且其RMSE、MAE、MAPE的数值均小于LSTM、VMD-LSTM模型的数值,表明VMD-SSA-LSTM模型的预测效果优于LSTM、VMD-LSTM模型。Fruits are the fourth largest crop category in China’s agricultural sector and play a vital role in the national economy. The fluctuations in fruit prices not only affect the cost of living for residents but also affect the income of fruit farmers. Therefore, it is crucial to forecast the trend of fruit prices. In this study, we selected the weekly wholesale prices of Red Fuji apples, Jufeng grapes, and Qilin watermelons from week 22 of 2021 to week 38 of 2024, a total of 174 weeks, and built the VMD-SSA-LSTM model to predict the prices of these three fruits. We also compared the fruit price prediction effects of the VMD-SSA-LSTM model with those of the LSTM and VMD-LSTM models. The experimental results show that the predicted values of the VMD-SSA-LSTM model are closest to the actual values, and its RMSE, MAE, and MAPE values are all smaller than those of the LSTM and VMD-LSTM models, indicating that the prediction effect of the VMD-SSA-LSTM model is better than that of the LSTM and VMD-LSTM models.
文摘获得真实的日面观测图像,是用户基于太阳望远镜开展科学和应用研究的基础,而平场定标是科学数据生产过程中的必要步骤之一,因为平场定标可以扣除太阳望远镜在成像过程中产生的不均匀性.“夸父一号”又名先进天基太阳天文台(Advanced Space-based Solar Observatory,ASO-S)卫星的载荷之一,莱曼阿尔法太阳望远镜(Lyman-alpha Solar Telescope,LST),包括3台科学仪器,具体来说是由一个双波段太阳日冕仪(Solar Corona Imager,SCI)以及白光太阳望远镜(White-light Solar Telescope,WST)和莱曼阿尔法全日面太阳成像仪(Solar Disk Imager,SDI)这两个全日面太阳望远镜构成.WST和SDI的探测器是互补金属氧化物半导体(Complementary Metal-Oxide-Semiconductor,CMOS),其平场本身的主要特征是由于激光退火造成的条纹结构,当CMOS探测器在紫外波段使用时会产生一定的衰减与辐射损伤,并且探测器上的水汽凝结和有机物的积累等污染,也会对所得平场产生一定影响.主要展示了ASO-S卫星发射两年多来,载荷LST的两个仪器WST和SDI在轨平场定标时使用的偏摆方案及其优化以及获得的平场图像和其随时间的演化情况等,并简要地介绍了WST和SDI探测器随时间的衰减和辐射损伤情况.
