Search

Copyright of Chinese Journal of Applied Chemistry is the property of Chinese Journal of Applied Chemistry and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Micronanoelectronic Technology is the property of Micronanoelectronic Technology Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Science & Technology of Food Industry is the property of Science & Technology of Food Industry Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Shandong Medical Journal is the property of Shandong Medical Health Newspapers and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Large Electric Machine & Hydraulic Turbine is the property of Large Electric Machine & Hydraulic Turbine Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Food Safety & Quality is the property of Journal of Food Safety & Quality Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Basic & Clinical Medicine is the property of Editorial Office of Basic & Clinical Medicine and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Taxi-out time is the main performance index to evaluate the operation efficiency of large airports. Scientifically and accurately predicting the taxi-out time of departing aircraft is very important to improve the operation efficiency. Firstly, the influencing factors and correlation of aircrafts’ taxi-out time were analyzed, and the aircraft taxi-out time prediction model based on back propagation (BP) neural network was constructed. In view of the shortcomings of BP neural network, such as sensitivity to initial weight and threshold, poor accuracy and stability, particle swarm optimization (PSO) and sparrow search algorithm (SSA) were used to obtain the optimal weight and threshold of BP neural network respectively. The prediction model optimized by the intelligent algorithm was verified by using the actual operation data of a hub airport in central and southern China for two weeks. The results show that the taxi-out time is strongly correlated with the half-hour average taxi-out time, the take-off queue length and the number of departing aircraft taxiing at the same time, moderately correlated with the number of taxiing arrival aircrafts at the same time, and weakly correlated with the taxiing distance and the number of conflict hot spots. The prediction result of the 4-elements combination prediction model considering the influencing factors of strong correlation and medium correlation is the best. The intelligent optimization algorithm can effectively improve the accuracy of aircraft taxi-out time prediction by obtaining the local optimal weight and threshold of neural network, but the calculation process takes longer. The prediction result of BP neural network based on PSO optimization is 1.13% higher than that of mean absolute percentage error (MAPE) before optimization, mean absolute error (MAE) is reduced by 4.48 s and root mean squared error (RMSE) is reduced by 4.68 s. And the prediction result of BP neural network optimized based on SSA is 3.05% higher than that of MAPE before optimization, MAE is reduced by 16.55 s and RMSE is reduced by 14.31 s. [ABSTRACT FROM AUTHOR]

Copyright of Chinese Journal of Tissue Engineering Research / Zhongguo Zuzhi Gongcheng Yanjiu is the property of Chinese Journal of Tissue Engineering Research and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Synthetic Crystals is the property of Journal of Synthetic Crystals Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Water Conservancy & Electric Power Technology & Application is the property of Omniscient Pte. Ltd. and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

In order to solve the problem of poor prediction accuracy of departure flight time by back propagation (BP) neural network, a prediction model of departure flight time was established based on support vector machine (SVM). Firstly, quantifiable factors affecting the departure time of flight were analyzedand a prediction model of departure time of flight was built based on correlation analysis. The results of taxi-out time prediction based on SVM and BP neural network were compared and analyzed. The conclusions are as follows: the taxi-out time of departing flights is strongly correlated with the number of launching flights in the same periodthe number of taking off flights in the same period, the number of flights in the same period and the average taxiing time in one hour. It is correlated with taxiing distance, number of turns and delay time but not significantly, and is not correlated with the time period at the departure time. The trend of prediction results based on SVM and BP neural network is consistent, and the accuracy of seven-tuple prediction results is the best considering strong correlation and moderate correlation factors. After introducing irrelevant factors, the prediction accuracy of the model will decrease. The accuracy of the SVM-based taxi-out time prediction model is significantly higher than that of the BP neural network prediction modeland the prediction accuracy within the taxi-out time error range ± 5 min can reach 98%. [ABSTRACT FROM AUTHOR]

Copyright of Science Technology & Engineering is the property of Chinese Society of Technology Economics and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Pharmaceutical Practice & Service is the property of Journal of Pharmaceutical Practice Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of China Brewing is the property of China Brewing Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of South Architecture / Nanfang Jianzhu is the property of South Architecture Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Engineering Management / Gongcheng Guanli Xuebao is the property of Journal of Engineering Management Editorial Office and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Mycosystema is the property of Mycosystema Editorial Board and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Telecommunication Engineering is the property of Telecommunication Engineering and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Systems Engineering & Electronics is the property of Journal of Systems Engineering & Electronics Editorial Department and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Chinese Journal of Clinical Healthcare is the property of Chinese Journal of Clinical Healthcare and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Copyright of Journal of Signal Processing is the property of Journal of Signal Processing and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

目的 探讨危重症患儿血清维生素A水平变化及意义.方法 选择重症监护病房收治的危重症患儿83例,入院24h内取其空腹静脉血,采用ELISA法检测血清维生素A,以血清维生素A水平＜0.70 μmol/L为缺乏组,0.70 ～＜ 1.05 μmol/L为亚临床缺乏组,1.05～ 2.07μmol/L为正常组.比较三组性别、年龄、原发病、伴发多脏器功能障碍综合征(MODS)、入院24h小儿危重症病例(PCIS)评分及儿童死亡危险(PRISM)评分、机械通气例数、28天存活率、住院时间.结果 83例危重症患儿血清维生素A水平为(1.06 +0.18) μmol/L,缺乏组0例、亚临床缺乏组43例(51.8％)、正常组40例(48.2％).亚临床缺乏组、正常组性别、年龄、原发病、伴发MODS、PCIS评分、机械通气例数、28天存活率、住院时间比较差异均无统计学意义(P均＞0.05),亚临床缺乏组PRISM评分高于正常组(P＜0.05).危重症患儿入院24 hPRISM评分与血清维生素A水平呈负相关(r=-0.186,P=0.001).结论 危重症患儿维生素A亚临床缺乏率较高,维生素A水平可能与病情危重程度有关. [ABSTRACT FROM AUTHOR]