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1.
This paper presents a novel No-Reference Video Quality Assessment (NR-VQA) model that utilizes proposed 3D steerable wavelet transform-based Natural Video Statistics (NVS) features as well as human perceptual features. Additionally, we proposed a novel two-stage regression scheme that significantly improves the overall performance of quality estimation. In the first stage, transform-based NVS and human perceptual features are separately passed through the proposed hybrid regression scheme: Support Vector Regression (SVR) followed by Polynomial curve fitting. The two visual quality scores predicted from the first stage are then used as features for the similar second stage. This predicts the final quality scores of distorted videos by achieving score level fusion. Extensive experiments were conducted using five authentic and four synthetic distortion databases. Experimental results demonstrate that the proposed method outperforms other published state-of-the-art benchmark methods on synthetic distortion databases and is among the top performers on authentic distortion databases. The source code is available at https://github.com/anishVNIT/two-stage-vqa.  相似文献   
2.
韩海坤  孙钢柱 《建筑经济》2020,41(1):104-109
构建工程咨询机构BIM技术应用能力评价的指标体系,提出改进的熵权TOPSIS评价模型,以4个典型的工程咨询单位为例,进行BIM技术运用能力评价。研究表明,BIM行业的整体水平已经有了明显的提升,但是区域间的发展还存在一定差距。  相似文献   
3.
在分析单一MU(Most Uncertainty)采样缺陷的基础上,提出一种"全局最优搜寻"方法 GOS(Global Optimal Search),并结合MU共同完成查询选择。GOS+MU方法中,GOS着眼全局寻找目标,在应用环境能提供的训练样本数量有限、分类器受训不充分时,该方法选择的对象学习价值高,能快速推进分类器学习进程;MU则能够在GOS采样失效情形下,利用分类器当前训练成果,选择查询不确定性最强的样本补充训练集。通过对网络商品的用户评论进行分类仿真,并比较其他采样学习方法的效果,证明了GOS+MU方法在压缩学习成本、提高训练效率方面的有效性。  相似文献   
4.
5.
The non-equiatomic FeCoNiAlSi alloy is prepared by the Bridgman solidification (BS) technique at different withdrawal velocities (V = 30, 100, and 200 μm/s). Various characterization techniques have been used to study the microstructure and crystal orientation. The morphological evolutions accompanying the crystal growth of the alloy prepared at different withdrawal velocities are nearly the same, from equiaxed grains to columnar crystals. The transition of coercivity is closely related to the local microstructure, while the saturation magnetization changes little at different sites. The coercivity can be significantly reduced from the equiaxed grain area to the columnar crystal area when the applied magnetic field direction is parallel to the crystal growth direction, no matter what is the withdrawal velocity. In addition, the alloy possesses magnetic anisotropy when the applied magnetic field is in different directions.  相似文献   
6.
High-entropy alloys (HEAs), as a new class of metallic materials, have received more and more attention due to its excellent mechanical properties. In this study, the hydrogen absorption properties, such as hydrogen absorption capacity, thermodynamics, kinetics and cyclic properties, as well as the hydride structure of a newly designed TiZrNbTa HEA were investigated. The results showed that multiple hydrides including ε-ZrH2, ε-TiH2 and β-(Nb,Ta)H were found in the TiZrNbTa HEA after hydrogenation. With the increase of temperature from 293 K to 493 K, the maximum hydrogen absorption capacity decreased from 1.67 wt% to 1.25 wt% and the plateau pressure related with β-(Nb,Ta)H hydrides increased from 1.6 kPa to 14.8 kPa. The formation enthalpy of β-(Nb,Ta)H hydride was determined to be −6.4 kJ/mol, which was less stable than that of NbH and TaH hydrides. The results also showed that the TiZrNbTa HEA exhibited a rapid hydrogen absorption kinetic even at the room temperature with a short incubation time, and the hydrogen absorption mechanism was determined to be the nucleation and growth mechanism. Moreover, the hydrogen absorption capacity at 293 K decreased slowly with the cycle numbers, and remained 86% capacity after 10 cycles. Cracking occurred after hydrogen absorption and became worse with cycles.  相似文献   
7.
在广播电视行业不断发展条件下,电视专题节目制作也受到受众高度重视。这就应提高电视专题节目制作质量,在满足广大受众日常观看要求同时,使得我国广播电视行业向着现代化方向发展。针对电视专题节目制作进行研究,首先阐述电视专题节目制作特点,之后阐述电视专题节目制作质量问题和相关提升对策。在解决电视专题节目制作问题同时,提升电视专题节目制作质量,继而彰显电视专题节目制作优势。  相似文献   
8.
为智能化地识别警戒作业人员出现的低觉醒、注意力下降的生理状态,本文介绍了一种基于FPGA和脑电信号处理的低觉醒状态检测与唤醒系统,系统通过传感器从大脑头皮采集脑电信号,转换为数字信号,经傅里叶变换获取了脑电信号的θ相对能量、α相对能量、重心频率、谱熵等4个特征量,由4个特征量表征低觉醒状态并运用支持向量机对低警戒状态进行识别,当识别出低觉醒状态时采用声音报警模块发出声音,唤醒警戒作业人员。设计系统能够较好地识别出低觉醒状态,识别率达90.8%,可为提高警戒作业工作绩效提供一种可穿戴的智能装备。  相似文献   
9.
Possibility of formation of quinary and senary equimolar high entropy oxides from the Co-Cr-Fe-Mg-Mn-Ni-O system is presented. Different proposed compositions are synthesized using the solid-state reaction route at high temperatures (900−1100 °C) and quenched to room temperature. Phase composition of the samples is studied, showing tendency toward formation of two main phases: rock salt-structured Fm-3 m and spinel-structured Fd-3 m. It is documented that the annealing temperature has a profound effect on stability of both structures, and at 1100 °C usually the highest content of Fm-3 m phase is usually observed. Three different oxides, namely, (Co,Cr,Fe,Mn,Ni)3O4, (Co,Cr,Fe,Mg,Mn)3O4 and (Cr,Fe,Mg,Mn,Ni)3O4 are obtained as single-phase materials, which structure can be described as the high entropy Fd-3 m spinel one. The latter two compounds have not been previously reported in the literature. Activated character of the electrical conductivity dependence on temperature is observed, with relatively high total conductivity at high temperatures and corresponding high absolute values of Seebeck coefficient.  相似文献   
10.
NOMENCLATUREd———embeddingdimension ,dimensionlessCd(r)———correlationsum ,dimensionlessN———numberofpairsofpointsontherecon structedattractor,dimensionlessr———scalingdistance ,dimensionlessDc ———correlationdimension ,dimensionlessK———Kolmogoroventropy ,bits/sR…  相似文献   
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