Rapid and large area acquisition of nitrogen(N)deficiency status is important for achieving the optimal fertilization of rice.Most existing studies,however,focus on the use of unmanned aerial vehicle(UAV)remote sensin...Rapid and large area acquisition of nitrogen(N)deficiency status is important for achieving the optimal fertilization of rice.Most existing studies,however,focus on the use of unmanned aerial vehicle(UAV)remote sensing to diagnose N nutrition in rice,while there are fewer studies on the quantitative description of the degree of N deficiency in rice,and the effects of the critical N concentration on the spectral changes in rice have rarely been explored.Therefore,based on the canopy spectral data obtained by remotely-sensed UAV hyperspectral images,the N content in rice was obtained through field sampling.The construction method of the rice curve for the northeastern critical N concentration was studied,and on this basis,N deficiency was determined.Taking the spectrum of the critical N concentration state as the standard spectrum,the spectral reflectivity data were transformed by the ratios and differences,and the feature extraction of the spectral data was carried out by the successive projections algorithm(SPA).Finally,by taking the characteristic band as the input variable and N deficiency as the output variable,a set of multivariate linear regression(MLR),long short-term memory(LSTM)inversion models based on extreme learning machine(ELM),and the nondominated sorting genetic algorithmⅢextreme learning machine(NSGA-Ⅲ-ELM)were constructed.The results showed two key aspects of this system:1)The correlation between the N deficiency data and original spectrum was poor,but the correlation between the N deficiency data and N deficiency could be improved by a difference change and ratio transformation;2)The inversion results based on the ratio spectrum and NSGA-Ⅲ-ELM algorithm were the best,as the R2values of the training set and validation set were 0.852 and 0.810,and the root mean square error(RMSE)values were 0.291 and 0.308,respectively.From the perspective of the spectral data,the inversion accuracy of the ratio spectrum was better than the accuracy of the original spectrum or difference spectrum.At the algorithm level,the model inversion results based on LSTM algorithms showed a serious overfitting phenomenon and poor inversion effect.The inversion accuracy based on the NSGA-Ⅲ-ELM algorithm was better than the accuracy of the MLR algorithm or the ELM algorithm.Therefore,the inversion model based on the ratio spectrum and NSGA-Ⅲ-ELM algorithm could effectively invert the N deficiency in rice and provide critical technical support for accurate topdressing based on the N status in the rice.展开更多
目的:总结并分析卵巢高钙血症型小细胞癌(small cell carcinoma of the ovary-hypercalcemic type,SCCOHT)的临床特点、诊断、治疗及预后。方法:对我院1994—2018年诊治的7例SCCOHT病例资料进行回顾性分析。结果:7例SCCOHT患者的平均年...目的:总结并分析卵巢高钙血症型小细胞癌(small cell carcinoma of the ovary-hypercalcemic type,SCCOHT)的临床特点、诊断、治疗及预后。方法:对我院1994—2018年诊治的7例SCCOHT病例资料进行回顾性分析。结果:7例SCCOHT患者的平均年龄为(23.4±9.9)岁,<30岁5例。Ⅰ期4例,Ⅲ期2例,Ⅳ期1例。临床多以腹痛、腹胀及发现盆腔包块为主诉,其中6例患者右侧卵巢受累,1例发生于左侧,5例(71.4%)诊断时伴血钙升高,6例(85.7%)血清CA125水平升高。7例患者均接受了手术及以铂类为基础的联合化疗,1例患者术后还接受了放疗。随访时间2~120个月,其中2例患者生存时间超过3年,其余5例均在发病2年内死亡。结论:SCCOHT是一类罕见的卵巢高度恶性肿瘤,预后很差,易发生于年轻女性,临床表现缺乏特异性,免疫组化有助于诊断,治疗以手术及以铂类为基础的化疗为主要治疗手段,最佳化疗方案有待进一步研究。展开更多
为了提高水中机器人2D仿真平台斯诺克赛项的得分,基于URWPGSim 2D(underwater robot water polo game simulator2D)仿真平台,采用最短距离和最小旋转角度求和比较的方法,实验得出了机器鱼以不同速度行进时其偏转角度呈奇偶特征,以此研...为了提高水中机器人2D仿真平台斯诺克赛项的得分,基于URWPGSim 2D(underwater robot water polo game simulator2D)仿真平台,采用最短距离和最小旋转角度求和比较的方法,实验得出了机器鱼以不同速度行进时其偏转角度呈奇偶特征,以此研究了其比赛策略和带球算法。在策略上,确定了红球-粉球组合最优、红球进洞顺序为从左到右、红球进中上洞、粉球进左下洞。基于此,确定了一种基于曲线路径的带球算法,给出了中上洞、左下洞带球进洞路径规划,采用虚拟点位和距离阈值的模糊控制理论来实现算法。仿真结果表明:优化后的带球算法效率高,实际比赛效果好,所提出的比赛策略和带球算法可应用于水下机器人运动控制。展开更多
基金supported by grants from the Key Project of Liaoning Provincial Department of Education,China(LSNZD202005)。
文摘Rapid and large area acquisition of nitrogen(N)deficiency status is important for achieving the optimal fertilization of rice.Most existing studies,however,focus on the use of unmanned aerial vehicle(UAV)remote sensing to diagnose N nutrition in rice,while there are fewer studies on the quantitative description of the degree of N deficiency in rice,and the effects of the critical N concentration on the spectral changes in rice have rarely been explored.Therefore,based on the canopy spectral data obtained by remotely-sensed UAV hyperspectral images,the N content in rice was obtained through field sampling.The construction method of the rice curve for the northeastern critical N concentration was studied,and on this basis,N deficiency was determined.Taking the spectrum of the critical N concentration state as the standard spectrum,the spectral reflectivity data were transformed by the ratios and differences,and the feature extraction of the spectral data was carried out by the successive projections algorithm(SPA).Finally,by taking the characteristic band as the input variable and N deficiency as the output variable,a set of multivariate linear regression(MLR),long short-term memory(LSTM)inversion models based on extreme learning machine(ELM),and the nondominated sorting genetic algorithmⅢextreme learning machine(NSGA-Ⅲ-ELM)were constructed.The results showed two key aspects of this system:1)The correlation between the N deficiency data and original spectrum was poor,but the correlation between the N deficiency data and N deficiency could be improved by a difference change and ratio transformation;2)The inversion results based on the ratio spectrum and NSGA-Ⅲ-ELM algorithm were the best,as the R2values of the training set and validation set were 0.852 and 0.810,and the root mean square error(RMSE)values were 0.291 and 0.308,respectively.From the perspective of the spectral data,the inversion accuracy of the ratio spectrum was better than the accuracy of the original spectrum or difference spectrum.At the algorithm level,the model inversion results based on LSTM algorithms showed a serious overfitting phenomenon and poor inversion effect.The inversion accuracy based on the NSGA-Ⅲ-ELM algorithm was better than the accuracy of the MLR algorithm or the ELM algorithm.Therefore,the inversion model based on the ratio spectrum and NSGA-Ⅲ-ELM algorithm could effectively invert the N deficiency in rice and provide critical technical support for accurate topdressing based on the N status in the rice.
文摘目的:总结并分析卵巢高钙血症型小细胞癌(small cell carcinoma of the ovary-hypercalcemic type,SCCOHT)的临床特点、诊断、治疗及预后。方法:对我院1994—2018年诊治的7例SCCOHT病例资料进行回顾性分析。结果:7例SCCOHT患者的平均年龄为(23.4±9.9)岁,<30岁5例。Ⅰ期4例,Ⅲ期2例,Ⅳ期1例。临床多以腹痛、腹胀及发现盆腔包块为主诉,其中6例患者右侧卵巢受累,1例发生于左侧,5例(71.4%)诊断时伴血钙升高,6例(85.7%)血清CA125水平升高。7例患者均接受了手术及以铂类为基础的联合化疗,1例患者术后还接受了放疗。随访时间2~120个月,其中2例患者生存时间超过3年,其余5例均在发病2年内死亡。结论:SCCOHT是一类罕见的卵巢高度恶性肿瘤,预后很差,易发生于年轻女性,临床表现缺乏特异性,免疫组化有助于诊断,治疗以手术及以铂类为基础的化疗为主要治疗手段,最佳化疗方案有待进一步研究。
文摘为了提高水中机器人2D仿真平台斯诺克赛项的得分,基于URWPGSim 2D(underwater robot water polo game simulator2D)仿真平台,采用最短距离和最小旋转角度求和比较的方法,实验得出了机器鱼以不同速度行进时其偏转角度呈奇偶特征,以此研究了其比赛策略和带球算法。在策略上,确定了红球-粉球组合最优、红球进洞顺序为从左到右、红球进中上洞、粉球进左下洞。基于此,确定了一种基于曲线路径的带球算法,给出了中上洞、左下洞带球进洞路径规划,采用虚拟点位和距离阈值的模糊控制理论来实现算法。仿真结果表明:优化后的带球算法效率高,实际比赛效果好,所提出的比赛策略和带球算法可应用于水下机器人运动控制。
