In this paper, the capability of neural networks and some approximation problens in system identification with neural networks are investigated. Some results are given: (i) For any function g ∈Llocp (R1) ∩S’ (R1) t...In this paper, the capability of neural networks and some approximation problens in system identification with neural networks are investigated. Some results are given: (i) For any function g ∈Llocp (R1) ∩S’ (R1) to be an Lp-Tauber-Wiener function, it is necessary and sufficient that g is not apolynomial; (ii) If g∈(Lp TW), then the set of is dense in Lp(K)’ (iii) It is proved that bycompositions of some functions of one variable, one can approximate continuous functional defined on compact Lp(K) and continuous operators from compact Lp1(K1) to LP2(K2). These results confirm the capability of neural networks in identifying dynamic systems.展开更多
BASF’s business declined in the first quarterof 2009. At Euro 12.2 billion, sales were23% lower than in the first quarter of 2008,primarily due to persistently weak demand.Income from operations(EBIT)before specialit...BASF’s business declined in the first quarterof 2009. At Euro 12.2 billion, sales were23% lower than in the first quarter of 2008,primarily due to persistently weak demand.Income from operations(EBIT)before specialitems fell by 58% to Euro 985 millionas a result of a substantial decrease in volumesin many divisions.Sales and earnings decline in all regions.In Asia Pacific, sales decreased by 42% inlocal currency terms and by 34% in展开更多
INEOS Phenol and Sinopec Yangzi Petrochemical Company have signed a Letterof Intent to study and negotiate a jointventure to build and operate a phenol/acetonemanufacturing site at the NanjingChemical Industry Park in...INEOS Phenol and Sinopec Yangzi Petrochemical Company have signed a Letterof Intent to study and negotiate a jointventure to build and operate a phenol/acetonemanufacturing site at the NanjingChemical Industry Park in Jiangsuprovince,eastern China.INEOS announcedJanuary 1 st.The expected annual capacity of the newfacility will be 400 000 tons of phenol and250 000 tons of acetone making it the largestplant of its kind in China.The展开更多
目的:探讨联合检测血清癌胚抗原(carcinoembryonic,CEA)、神经元特异性烯醇化酶(neuron specific enolase,NSE)、细胞角蛋白19片段(cyfra 21-1)和CA125对肺癌的诊断价值。方法:应用电化学发光免疫分析法,测定2010-01-19-2012-12-24泸州...目的:探讨联合检测血清癌胚抗原(carcinoembryonic,CEA)、神经元特异性烯醇化酶(neuron specific enolase,NSE)、细胞角蛋白19片段(cyfra 21-1)和CA125对肺癌的诊断价值。方法:应用电化学发光免疫分析法,测定2010-01-19-2012-12-24泸州医学院附属医院病理或细胞学确诊70例肺癌和54例肺部其他良性疾病患者血清中CEA、NSE、cyfra21-1和CA125,结合主成分分析(principal component analysis,PCA)法、受试者工作特征曲线(receive operating characteristic curve,ROC)、偏最小二乘判别分析(partial-least-squares discriminant analysis,PLS-DA)线性模型和人工神经网络多层感知(artificial neural network-multiplayer perceptron,ANN-MPL)非线性模型对CEA、NSE、cyfra21-1和CA125进行建模分析。结果:肺癌组血清CEA、NSE、cyfra21-1和CA125水平均高于对照组。肺癌组血清中CEA、NSE和cyfra21-1水平显著升高,差异有统计学意义,P<0.05。PCA模型中肺癌组个体空间分布较分散,而对照组则能较好地聚类,2组个体有分离趋势。PLS-DA模型能够很好地鉴别肺癌组和对照组,P<0.01;具有100%的灵敏度、96.3%的特异性、98.4%的准确性和97.7%的预测能力。ROC曲线分析显示,CEA、cyfra21-1、NSE和CA125的ROC曲线下面积(area under the curve,AUC)分别为0.787(P<0.05)、0.784(P<0.05)、0.563(P<0.05)和0.503(P=0.59)。在ANNMPL-ROC曲线模型中,联合检测CEA和cyfra21-1的AUC为0.849,均优于单一的肿瘤标志,具有74.3%的灵敏度、76.0%的特异性,75.9%准确性和75.0%的预测能力,P<0.05。联合CEA、NSE、cyfra21-1和CA125的AUC为0.880,灵敏度为84.3%,特异性为76.0%,具有80.6%准确性和82.5%的预测能力。结论:ANN-MPL的ROC模型中联合检测血清CEA、NSE、cyfra21-1和CA125与联合检测CEA和cyfra21-1相比灵敏度略有升高而特异性不变,2种模型的诊断效能相当。从经济和临床应用价值考虑,可选择联合检测CEA和cyfra21-1用于肺癌的早期诊断。展开更多
基金Project supported by the Climbing Programme-National Key Project for Fundamental Research in China, Grant NSC 92092 and NSF 19371022
文摘In this paper, the capability of neural networks and some approximation problens in system identification with neural networks are investigated. Some results are given: (i) For any function g ∈Llocp (R1) ∩S’ (R1) to be an Lp-Tauber-Wiener function, it is necessary and sufficient that g is not apolynomial; (ii) If g∈(Lp TW), then the set of is dense in Lp(K)’ (iii) It is proved that bycompositions of some functions of one variable, one can approximate continuous functional defined on compact Lp(K) and continuous operators from compact Lp1(K1) to LP2(K2). These results confirm the capability of neural networks in identifying dynamic systems.
文摘BASF’s business declined in the first quarterof 2009. At Euro 12.2 billion, sales were23% lower than in the first quarter of 2008,primarily due to persistently weak demand.Income from operations(EBIT)before specialitems fell by 58% to Euro 985 millionas a result of a substantial decrease in volumesin many divisions.Sales and earnings decline in all regions.In Asia Pacific, sales decreased by 42% inlocal currency terms and by 34% in
文摘INEOS Phenol and Sinopec Yangzi Petrochemical Company have signed a Letterof Intent to study and negotiate a jointventure to build and operate a phenol/acetonemanufacturing site at the NanjingChemical Industry Park in Jiangsuprovince,eastern China.INEOS announcedJanuary 1 st.The expected annual capacity of the newfacility will be 400 000 tons of phenol and250 000 tons of acetone making it the largestplant of its kind in China.The
