transform

摘要： 肾在人体内是一个很重要的器官,而肾实质是很常见的一种肾病。目前关于肾实质病变的判断是临床医生通过标注,人工进行判断的。这样人工的方式需要大量的时间以及人工成本,也因此我们亟需一种自动化的标注分割方法,从而提升肾实质的分割效率与精度。本文针对小儿肾实质的分割问题,绘制了一套儿童的肾实质数据集,并且根据数据集的特点提出了一种基于transform的分割方法。Transform架构不同于传统卷积提取特征的架构,transform更加关注语义的上下文信息,我们用它作为编码器的一部分来提取语义信息,从序列到序列学习的角度,为图像分割提供了一个全新的视角。这样做不仅改善了分辨率降低导致感受野下降的问题,同时也改善了跳跃连接会带来语义间隙的问题,得到最终的分割结果图,极大地减少了人工标注的代价。本文的代码是基于pytorch框架进行的编程,在所提出的肾图数据集上进行的实验,并将本文提出的网络与经典的FCN、SegNet、U-Net和Deeplab-V3+做了对比实验。结果显示本文提出的方法在precision、dice_coeff、recall三种评价指标上(对比其网络在这三种指标上最优的结果),分别提升了1.99%、1.65%、2.23%和3.001%,其效果也得到了专业医生的认可。

摘要： 三维点云在机器人与自动驾驶中都有着普遍的应用,深度学习在二维图像上的研究成果显著,但是如何利用深度学习识别不规则的三维点云,仍然是一个开放性的问题。目前大场景点云自身数据的复杂性,点云扫描距离的变化造成点的分布不均匀,噪声和异常点引起的挑战性依然存在。针对于现有的深度学习网络框架对于激光点云数据的分类效率不高以及分类精度低的问题,提出一种基于激光点云特征图像与Light-BotNet相结合的CNN-Transform框架。该框架在于通过对点云数据进行特征提取,以相邻的特征点构造点云特征图像作为网络框架的输入,最后以Light-BotNet为网络框架模型进行点云分类训练。实验结果表明,该方法与现有的多数点云分类方法相比,能够较好地提升激光点云的分类效率以及分类精度。

摘要： 针对传统Web设计,需借助JavaScript脚本或者Flash来实现动画效果的问题,CSS3新增了过渡、变形和动画属性,让动画特性实现得更加简单。文章依次介绍了实现动画的三个核心技术即过渡(transition)属性、变形(transform)属性和动画(animation)属性,并在此基础上以立方体盒子的展开与旋转效果为例,从效果描述、结构分析、样式分析、制作页面结构、定义CSS样式这五个方面具体阐述了基于CSS3动画效果的实现过程。基于HTML5+CSS3的动画效果的实现大大提高了网页开发的效率,大幅度提升了用户的体验感。

摘要： 近年来,新技术不断涌现,在网页中增加动画效果可以大大提高页面的友好性与趣味性.运用CSS3.0中新增的变形动画属性和过渡动画属性,能够在网页中实现这些特殊的效果.笔者结合两个综合案例的演示,分别探讨了在CSS3.0中如何运用transform属性实现网页指定元素的变形操作,如何结合transition属性使元素的动画效果过渡得更加平滑与生动.

摘要： Dear editor,The fractional Fourier transform(FRFT) was proposed by Wiener in 1929. As an important and powerful analyzing tool for time-frequency analysis, the FRFT has been applied in a lot of fields [1, 2] such as signal processing, optics, radar, and quantum mechanics. According to a similar definition of the FRFT, several other important fractional transforms [3, 4] were studied such as the fractional wavelet transform, the fractional cosine, the fractional sine, and the fractional Hankel transform.

摘要： The objective of this research is to study the dynamic response characteristics of a three-beam system with intermediate elastic connections under a moving load/mass-spring.In this study,the finite Sine-Fourier transform was performed for the dynamic partial differential equations of a simply supported three-beam system(SSTBS)under a moving load and a moving mass-spring,respectively.The dynamic partial differential equations were transformed into dynamic ordinary differential equations relative to the time coordinates,and the equations were solved and the displacement Fourier amplitude spectral expressions were obtained.Finally,based on finite Sine-Fourier inverse transform,the expressions for dynamic response of SSTBS under the moving load and moving mass-spring were obtained.The proposed method,along with ANSYS,was used to calculate the dynamic response of the SSTBS under a moving load/mass-spring at different speeds.The results obtained herein were consistent with the ANSYS numerical calculation results,verifying the accuracy of the proposed method.The influence of the load/mass-spring’s moving speed on the dynamic deflections of SSTBS were analyzed.SSTBS has several critical speeds under a moving load/mass-spring.The vertical acceleration incurred by a change in the vertical speed of SSTBS due to the movement of mass-spring and the centrifugal acceleration produced by the movement of massspring on the vertical curve generated by SSTBS vibration could not be neglected.

摘要： Structural health monitoring(SHM)is a process of implementing a damage detection strategy in existing structures to evaluate their condition to ensure safety.The changes in the material,geometric and/or structural properties affect structural responses,which can be captured and analyzed for condition assessment.Various vibration-based damage detection algorithms have been developed in the past few decades.Among them,wavelet transform(WT)gained popularity as an efficient method of signal processing to build a framework to identify modal properties and detect damage in structures.This article presents the state-of-the-art implementation of various WT tools in SHM with a focus on civil structures.The unique features and limitations of WT,and a comparison of WT and other signal processing methods,are further discussed.The comprehensive literature review in this study will help interested researchers to investigate the use of WT in SHM to meet their specific needs.

摘要： In this technical paper, the oxidation mechanism and kinetics of aluminum powders are discussed in great details. The potential applications of spherical aluminum powders after oxidation to be part of the surging arresting materials are discussed. Theoretical calculations of oxidation of spherical aluminum powders in a typical gas fluidization bed are demonstrated. Computer software written by the author is used to carry out the basic calculations of important parameters of a gas fluidization bed at different temperatures. A mathematical model of the dynamic system in a gas fluidization bed is developed and the analytical solution is obtained. The mathematical model can be used to estimate aluminum oxide thickness at a defined temperature. The mathematical model created in this study is evaluated and confirmed consistently with the experimental results on a gas fluidization bed. Detail technical discussion of the oxidation mechanism of aluminum is carried out. The mathematical deviations of the mathematical modeling have demonstrated in great details. This mathematical model developed in this study and validated with experimental results can bring a great value for the quantitative analysis of a gas fluidization bed in general from a theoretical point of view. It can be applied for the oxidation not only for aluminum spherical powders, but also for other spherical metal powders. The mathematical model developed can further enhance the applications of gas fluidization technology. In addition to the development of mathematical modeling of a gas fluidization bed reactor, the formation of oxide film through diffusion on both planar and spherical aluminum surfaces is analyzed through a thorough mathematical deviation using diffusion theory and Laplace transformation. The dominant defects and their impact to oxidation of aluminum are also discussed in detail. The well-controlled oxidation film on spherical metal powders such as aluminum and other metal spherical powders can potentially become an important part of switch devices of surge arresting materials, in general.

摘要： Ground Penetration Radar is a controlled source geophysical method which uses high frequency electromagnetic waves to study shallow layers. Resolution of this method depends on difference of electrical properties between target and surrounding electrical medium, target geometry and used bandwidth. The wavelet transform is used extensively in signal analysis and noise attenuation. In addition, wavelet domain allows local precise descriptions of signal behavior. The Fourier coefficient represents a component for all time and therefore local events must be described by the phase characteristic which can be abolished or strengthened over a large period of time. Finally basis of Auto Regression (AR) is the fitting of an appropriate model on data, which in practice results in more information from data process. Estimation of the parameters of the regression model (AR) is very important. In order to obtain a higher-resolution spectral estimation than other models, recursive operator is a suitable tool. Generally, it is much easier to work with an Auto Regression model. Results shows that the TQWT in soft thresholding mode can attenuate random noise far better than TQWT in hard thresholding mode and Autoregressive-FX method.

摘要： 本发明涉及软件通讯类技术领域，公开了基于ShapeletTransform提取特征的数字信号数据构造时序图像的新方法，首先利用Shapelet Transform算法对采集的一维数字信号数据进行Shapelet提取，获取Shapelets后，结合任意的图像转换方法，将一维的Shapelets转换为二维的时序图像；最后将时序图像输入任意机器学习的算法进行分类识别、检测。本发明通过Shapelet算法提取后获得的数字信号数据具备更好的可解释性，利用图像转换方法将其转换成二维图像时，能保留数字信号数据里的时间相关性。在基于具有时间相关性的二维图像进行分析时，可结合任意的机器学习方法，适用范围广。

摘要： 本发明涉及一种基于transform注意力机制的肺结节检测方法及装置，所述方法包括以下步骤：获取3D肺部图像，对所述3D肺部图像进行预处理；构建Transformer自注意力机制的肺结节检测模型；输入所述3D肺部图像至训练和测试后的所述肺结节检测模型；利用所述肺结节检测模型对所述3D肺部图像进行结节检测，输出肺结节候选区域；消除所述肺结节候选区域的非结节区域，得到肺结节检测结果；本发明实现对肺部图像的肺结节自动检测，灵敏度高，准确性强，效率高。