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排序方式: 共有90条查询结果,搜索用时 15 毫秒
1.
Significance of international mergers and acquisition
Good for easing lack of domestic oil reserves
China oil production is under severe deficit due to insufficient resources. Annual average growth rate of crude oil consumption was 7.41%, but annual average growth rate of crude oil supply was only 1.95% in China in past 10 years. Oil supply could not meet demand of economic development. It is predicted that degree of China's dependence on foreign will be as high as 60% in 2015. 相似文献
Good for easing lack of domestic oil reserves
China oil production is under severe deficit due to insufficient resources. Annual average growth rate of crude oil consumption was 7.41%, but annual average growth rate of crude oil supply was only 1.95% in China in past 10 years. Oil supply could not meet demand of economic development. It is predicted that degree of China's dependence on foreign will be as high as 60% in 2015. 相似文献
2.
大亚湾核电站的9LGR 至LGC6.6 kV 电缆原设计有错误, 存在事故隐患。通过对电缆载流量及其所带负荷的计算、比较, 找出错误的原因, 提出并论证改进方案。该方案实施后, 纠正了原设计错误, 消除了事故隐患, 满足了电厂的设计要求, 提高了LGC 系统的电源可靠性。 相似文献
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迁移近邻传播聚类算法 总被引:2,自引:1,他引:2
在目标域可利用数据匮乏的场景下,传统聚类算法的性能往往会下降.在该场景下,通过抽取源域中的有用知识用于指导目标域学习以得到更为合适的类别信息和聚类性能,是一种有效的学习策略.借此提出一种基于近邻传播的迁移聚类(transfer affinity propagation,简称TAP)算法,在源域和目标域数据分布相似的情况下,通过引入迁移学习机制来改善近邻传播聚类(affinity propagation,简称AP)算法在数据匮乏场景下的聚类性能.为保证迁移的有效性,TAP在综合考虑源域和目标域的统计特性及几何特征的基础上改进AP算法中的消息传递机制使其具备迁移能力,从而达到辅助目标域学习的目的.此外,通过TAP对应的因子图,亦可说明TAP可以以类似AP的消息传递机制,在目标域数据匮乏的情况下进行高效的知识迁移,为最终所获得的聚类结果提供了保证.在模拟数据集和真实数据集上的仿真实验结果显示,所提出的算法较之经典AP算法在处理非充分数据聚类任务时具有更佳的性能. 相似文献
6.
Demakis George J.; Sweet Jerry J.; Sawyer Thomas P.; Moulthrop Mark; Nies Kristie; Clingerman Steven 《Canadian Metallurgical Quarterly》2001,13(2):240
This study examines how well the discrepancy between predicted and obtained Wechsler Adult Intelligence Scale–Revised (WAIS–R) scores discriminate between insufficient effort (IE) and traumatic brain injury (TBI). The 27 IE patients performed significantly more poorly on the WAIS–R than the 48 moderate-severe TBI patients. Premorbid IQs were calculated with formulae that use demographics (Barona Index) or demographics and WAIS–R performance (Best-3 and the Oklahoma Premorbid Intelligence Estimation). Predictions were similar on the Barona, but IE patients' predicted IQs were lower than TBIs for measures with a performance component. IE patients demonstrated a greater discrepancy score (i.e., predicted IQ—obtained IQ) than TBIs; variable levels of sensitivity and specificity were obtained when discriminate functions were developed on these scores. The potential advantage of using discrepancy scores versus performance-based measures to detect insufficient effort is discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
7.
The robot joint is an important component of the construction robot, and its fault diagnosis can ensure the exact execution of building jobs, stable operation, and timely prevention of probable safety mishaps. However, deep learning-based fault diagnosis needs a multitude of measured fault data, which is difficult to obtain for various reasons. To solve the problem of insufficient data, a digital twin-assisted fault diagnosis system for robot joints is proposed. First, a simplified dynamics model of the robot joint is developed to generate the virtual entity data which can be used as the X-domain data for the digital twin model. Second, a CycleGAN-based digital twin model is proposed to map the virtual entity (X-domain) data to the physical entity (Y-domain) utilizing only a small amount of measured data. In the end, a test-rig for the robot joint is built to simulate the robot's working conditions, and the CNN-ResNet classifier is utilized to verify the effectiveness of the simulated data generated by the digital twin model. The results show that the fault diagnosis accuracy can be increased from 32.5% to 98.86% utilizing only 400 sets of measured data. 相似文献
8.
针对以往预测模型在数据少和噪音干扰下出现预测精度降低的问题,基于分形理论,尝试建立改进的变维分形预测模型,并以小湾工程边坡位移监测数据为例,选取D1、D2曲线作为预测模型的分形参数曲线,计算各曲线的分段分形维数,对位移进行预测,并分别用灰色模型GM(1,1)和BP神经网络进行对比预测.结果证明,这种方法充分利用了分形理论自相似性的特点,抗噪性强,能较好地应用于小数据量监测数据的预测,并且精度较高,有着良好的应用前景. 相似文献
9.
绥中36-1油田欠注井占总注入井井数的23%,主要是注入压力高导致欠注。对该油田储层特征、注水水质、注聚井堵塞物等因素进行分析,剖析注入压力高的原因。研究表明:储层胶结疏松、泥质含量高、微粒易运移、水敏性强是储层欠注内在因素。外因主要是注水水质超标、管壁腐蚀结垢严重、聚合物吸附堵塞。通过加强腐蚀研究工作、水质分级控制、除铁杀菌以及优化加药系统等措施可有效控制注水水质。注水井酸化体系中强化对Fe、O、S等元素化合物的溶蚀,注聚系统通过加多重滤网过滤并运用复合型化学解堵剂进行解堵可有效解除注入井堵塞,达到增注的目的。 相似文献
10.
考虑缺水滞后效应的作物-水模型研究 总被引:9,自引:1,他引:8
本文依据作物生理学有限缺水理论,考虑作物不同生育阶段缺水对叶面积系数、腾发量变化及产量影响的滞后效应,假设这种滞后影响过程的现在阶段只与将来阶段有关,而将来阶段与过去阶段无关,经单阶段和多阶段缺水的两种田间灌溉试验,求得改进的加法模型即考虑缺水滞后效应的作物水模型(LEMCRW),与常见的3种国外MCRW比较具有较广泛的适应性和较好精度,只要正确选用不同的敏感指标,可供单阶段和多阶段缺水对产量影响的非充分灌溉模拟. 相似文献