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With the advent of Big Data era has seen both the volumes and update rates of data increase rapidly. The granular structure of an information system is evolving with time when redundancy data leaves and new data arrives. In order to quickly achieve the rough approximations of dynamic attribute set interval-valued ordered information system that the attribute set varies over time. In this study, we proposed two dynamic computing rough approximations approaches for time-evolving information granule interval-valued ordered information system which induced by the deletion or addition some attributes, respectively. The updating mechanisms enable obtaining additional knowledge from the varied data without forgetting the prior knowledge. According to these established computing rules, two corresponding dynamic computing algorithms are designed and some examples are illustrated to explain updating principles and show computing process. Furthermore, a series of experiments were conducted to evaluate the computational efficiency of the studied updating mechanisms based on several UCI datasets. The experimental results clearly indicate that these methods significantly outperform the traditional approaches with a dramatic reduction in the computational efficiency to update the rough approximations. 相似文献
43.
堆垛机组导向装置的优化设计经导柱式导向装置、早期连杆式导向装置、新型连杆式导向装置三个过程,通过不断的技术改进,产品得到逐步完善。本文从优化设计角度,分析原有结构的不足,推出导向装置的新型结构形式并提高了堆垛机组导向装置的动力臂幅度,使机组动作更加灵活、可靠。 相似文献
44.
1,4-bis(2-cyano styryl)benzene (2-CSB) crystal with cyano substituent groups introduced to the terminal phenyl rings of distyrylbenzene (DSB) has been prepared and its luminescence efficiency could be as high as ∼55%. Based on the analyses of cyclic voltammetry and crystal structure, cyano substituents not only lower the LUMO level but also result in a change of the packing mode from the herringbone arrangement to the face-to-face slipped π stacking motif. Then field-effect transistors (FETs) based on high-quality 2-CSB crystals grown by the physical vapor transport method have been fabricated and the highest hole and electron mobilities were measured as 0.66 and 0.29 cm2/Vs, which enhanced the corresponding values of DSB crystal by up to one and two orders of magnitude, respectively. 2-CSB crystal simultaneously combined the high luminescence and the well-balanced mobility is expected to be of interest for the fundamental research of organic light-emitting devices. 相似文献
45.
J.A. MorkowskiG. Che?kowska M. WerwińskiA. Szajek R. Tro?C. Neise 《Journal of Alloys and Compounds》2011,509(25):6994-6998
The room temperature X-ray photoemission spectrum of the ferromagnetic compound UCu2Si2 (TC = 100 K) was measured using an Al Kα source. Related theoretical spectra were computed from densities of electronic states obtained in the local density approximation (LDA), the generalized gradient approximation (GGA), and using the GGA + U method. The calculated spectrum is in a good agreement with the experimental one. The spin polarized calculations based on the GGA + U approach as well as GGA/LSDA with orbital polarization (OP) corrections taken into account provide values of the total magnetic moment in reasonable agreement with the experimental values ranging between 1.6 and 2.0 μB/U atom. 相似文献
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结合堆载预压法在广东科学中心软土地基处理工程中的应用实践,重点对其加固机理、方案设计及现场施工方法进行了探讨,工程实践表明,该法处理软土地基效果明显,可供类似工程参考。 相似文献
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《钢铁研究学报(英文版)》2011,(Z1):306-309
In order to study the effect of alloy elements on mechanical properties of quenching and partitioning steels,the Q and P heat treatments on different chemical composition steels were carried on in lab.The tensile test results indicated the strength of Nb+Ti-bearing steel was not increasing as expected,but lower than that of the Nb+Ti-free steel,and the elongation was raised to 26% from 9%.The Nb+Ti-bearing steel microstructures after tensile test were detected by TEM and found a certain amount of twins in the deformed microstructure while the deformed microstructure mainly was lath martensite in Nb+Ti-free steel,which means the addition of Nb and Ti elements could cause the twinning induced plasticity by inhibiting the phase transformation from austenite to martensite.Based on above analysis,adding trace Nb element could greatly increase the stacking fault energy of the retained austenite,which is beneficial to the formation of twins,and the formation of twins would lower the strength slightly and raise the elongation drastically. 相似文献
50.
在H2SO4电解液中对高纯铝箔进行阳极氧化,考察分析了电解液浓度对多孔阳极氧化铝膜的影响,结果表明:随硫酸电解液浓度的增加,纳米孔孔径逐渐增大,孔密度降低,孔的有序性先提高后降低;采用23 V直流电压进行阳极氧化,电解液浓度为0.6~1.0 mol/L时制得的氧化铝膜孔径均匀性及有序度均较好,尤其以0.8 mol/L H2SO4最佳;阳极氧化铝膜的厚度随电解液浓度的提高而增大;电解液浓度过高易于将铝箔快速击穿。 相似文献