目的:利用便携式近红外(near infrared,NIR)光谱仪与化学计量学方法预测黄桃的腐败时间。方法:利用便携式NIR光谱仪采集黄桃样本的漫反射光谱,通过光谱预处理方法提高数据特征,采用偏最小二乘法(partial least squares,PLS)建立黄桃腐...目的:利用便携式近红外(near infrared,NIR)光谱仪与化学计量学方法预测黄桃的腐败时间。方法:利用便携式NIR光谱仪采集黄桃样本的漫反射光谱,通过光谱预处理方法提高数据特征,采用偏最小二乘法(partial least squares,PLS)建立黄桃腐败时间的预测模型。通过均方根误差(root mean square error,RMSE)和决定系数(coefficient of determination,R^(2))评估模型的预测效果。结果:模型对黄桃腐败时间预测的R^(2)为0.63,RMSE为4.09 d。结论:NIR光谱结合化学计量学方法能够实现黄桃腐败时间的无损、准确预测。展开更多
As conventional communication systems based on classic information theory have closely approached Shannon capacity,semantic communication is emerging as a key enabling technology for the further improvement of communi...As conventional communication systems based on classic information theory have closely approached Shannon capacity,semantic communication is emerging as a key enabling technology for the further improvement of communication performance.However,it is still unsettled on how to represent semantic information and characterise the theoretical limits of semantic-oriented compression and transmission.In this paper,we consider a semantic source which is characterised by a set of correlated random variables whose joint probabilistic distribution can be described by a Bayesian network.We give the information-theoretic limit on the lossless compression of the semantic source and introduce a low complexity encoding method by exploiting the conditional independence.We further characterise the limits on lossy compression of the semantic source and the upper and lower bounds of the rate-distortion function.We also investigate the lossy compression of the semantic source with two-sided information at the encoder and decoder,and obtain the corresponding rate distortion function.We prove that the optimal code of the semantic source is the combination of the optimal codes of each conditional independent set given the side information.展开更多
文摘目的探讨焦点解决短期治疗(Solution-focused brief therapy,SFBT)联合叙事护理对实施安宁疗护晚期癌症患者焦虑抑郁及生活质量的影响。方法选取2022年8月至2023年5月晚期癌症安宁疗护患者作为研究对象,入院时采用医院焦虑抑郁量表(Hospital anxiety and de-pression scale,HADS)进行调查,筛选评分≥8分的患者纳入本研究(n=110),按照随机数字表法分为对照组(n=55)和试验组(n=55)。对照组采用安宁疗护常规护理,试验组在对照组的基础上采用焦点解决短期治疗联合叙事护理进行干预。比较两组干预前后焦虑自评量表(Self-rating anxiety scale,SAS)、抑郁自评量表(Self-rating depression scale,SDS)和癌症治疗功能评价量表(Functional assessment of cancer therapy,FACT-G)评分的差异,评价干预效果。结果因病情变化或死亡,试验组完成52例,对照组完成53例。干预前,试验组和对照组SAS、SDS、FACT-G评分比较差异均无统计学意义(P>0.05);干预后,试验组SAS、SDS、FACT-G评分分别为(42.52±2.30)分、(57.63±3.80)分、(67.54±2.52)分,对照组SAS、SDS、FACT-G评分分别为(47.29±2.73)分、(62.25±2.87)分、(64.39±3.08)分,两组比较差异均有统计学意义(P<0.05)。结论SFBT联合叙事护理干预,可降低晚期癌症患者的负面情绪,缓解抑郁焦虑,提高其生活质量。
文摘目的:利用便携式近红外(near infrared,NIR)光谱仪与化学计量学方法预测黄桃的腐败时间。方法:利用便携式NIR光谱仪采集黄桃样本的漫反射光谱,通过光谱预处理方法提高数据特征,采用偏最小二乘法(partial least squares,PLS)建立黄桃腐败时间的预测模型。通过均方根误差(root mean square error,RMSE)和决定系数(coefficient of determination,R^(2))评估模型的预测效果。结果:模型对黄桃腐败时间预测的R^(2)为0.63,RMSE为4.09 d。结论:NIR光谱结合化学计量学方法能够实现黄桃腐败时间的无损、准确预测。
基金partly supported by NSFC under grant No.62293481,No.62201505partly by the SUTDZJU IDEA Grant(SUTD-ZJU(VP)202102)。
文摘As conventional communication systems based on classic information theory have closely approached Shannon capacity,semantic communication is emerging as a key enabling technology for the further improvement of communication performance.However,it is still unsettled on how to represent semantic information and characterise the theoretical limits of semantic-oriented compression and transmission.In this paper,we consider a semantic source which is characterised by a set of correlated random variables whose joint probabilistic distribution can be described by a Bayesian network.We give the information-theoretic limit on the lossless compression of the semantic source and introduce a low complexity encoding method by exploiting the conditional independence.We further characterise the limits on lossy compression of the semantic source and the upper and lower bounds of the rate-distortion function.We also investigate the lossy compression of the semantic source with two-sided information at the encoder and decoder,and obtain the corresponding rate distortion function.We prove that the optimal code of the semantic source is the combination of the optimal codes of each conditional independent set given the side information.
