基于空间光调制器的多层图像的构建与可视化研究

 为解决实时直观地观察多层再现图像的问题,提出利用发光材料实现其可视化.针对由沿光轴方向的二维图层组成的空间图像,利用高效、快速的三维Gerchberg-Saxton算法,得到位相型计算全息图,并通过计算机进行了数字模拟再现.阐述了三维Gerchberg-Saxton算法的流程,并搭建了基于液晶空间光调制器的位相全息图光学再现与可视化光路.利用液晶空间光调制器的灰度-位相曲线把计算全息图转换为灰度图,加载在液晶空间光调制器上,再现出高质量的三维光场,同时利用量子点材料的荧光特性实现了图像的可视化.实验结果表明,光学再现与计算机模拟结果较吻合.该技术在医学、军事、三维显示、微加工以及显微技术等领域有重要应用价值.     

Visualizing number sequences: Secondary preservice mathematics teachers’ constructions of figurate numbers using magnetic color cubes

This study is about preservice secondary mathematics teachers’ visualization of summation formulas modeled by magnetic color cubes representations. The theoretical framework for this research draws from studies on quantitative reasoning (Smith and Thompson, 2008, Thompson, 1995) and quantitative transformations (Schwartz, 1988). Data consist of videotaped qualitative interviews during which preservice mathematics teachers were asked to construct growing rectangles representing summation formulas. Data analysis is based on analytic induction and constant comparison methodology. Preservice teachers provided a diversity of additive and multiplicative visualizations. Results indicate that quantitative reasoning and mapping structures are fundamental constructs in establishing additive and multiplicative visualizations, hence constructing summation formulas meaningfully. Preservice teachers often had difficulties in explaining the relationships between the same-valued linear and areal quantities. They also established the rectangle condition as the essence of multiplicative visualization.     

Tools and resources for metabolomics research community: A 2017–2018 update

The scale at which MS‐ and NMR‐based platforms generate metabolomics datasets for both research, core, and clinical facilities to address challenges in the various sciences—ranging from biomedical to agricultural—is underappreciated. Thus, metabolomics efforts spanning microbe, environment, plant, animal, and human systems have led to continual and concomitant growth of in silico resources for analysis and interpretation of these datasets. These software tools, resources, and databases drive the field forward to help keep pace with the amount of data being generated and the sophisticated and diverse analytical platforms that are being used to generate these metabolomics datasets. To address challenges in data preprocessing, metabolite annotation, statistical interrogation, visualization, interpretation, and integration, the metabolomics and informatics research community comes up with hundreds of tools every year. The purpose of the present review is to provide a brief and useful summary of more than 95 metabolomics tools, software, and databases that were either developed or significantly improved during 2017–2018. We hope to see this review help readers, developers, and researchers to obtain informed access to these thorough lists of resources for further improvisation, implementation, and application in due course of time.     

Relationship between thermal stratification and flow patterns in steam-quenching suppression pool

This study aims to examine the relationship between thermal stratification and flow patterns in a steam-quenching suppression pool using particle image velocimetry. Thermal stratification was experimentally evaluated in a depressurized water pool under different steam mass flux conditions. The time evolution of the temperature profile of the suppression pool was presented with the variation of condensation regimes, and steam condensation processes were visualized using a high-speed camera. The thermal stratification condition was classified into full mixing, gradual thermal stratification, and developed thermal stratification. It was found that the condition was determined by the flow patterns depending on the force balance between buoyancy and momentum. The force balance affected both the condensation regime and the flow pattern, and hence, the flow pattern was changed with the condensation regime. However, the force balance had a sensitive influence on the flow in the pool; therefore, distinct flow patterns were observed even in the same condensation regime.     

Using box indices in supporting comparison in multiobjective optimization

Because of the conflicting nature of criteria or objectives, solving a multiobjective optimization problem typically requires interaction with a decision maker who can specify preference information related to the objectives in the problem in question. Due to the difficulties of dealing with multiple objectives, the way information is presented plays a very important role. Questions posed to the decision maker must be simple enough and information shown must be easy to understand. For this purpose, visualization and graphical representations can be useful and constitute one of the main tools used in the literature. In this paper, we propose to use box indices to represent information related to different solution alternatives of multiobjective optimization problems involving at least three objectives. Box indices are an intelligible and easy to handle way to represent data. They are based on evaluating the solutions in a natural and rough enough scale in order to let the decision maker easily recognize the main characteristics of a solution at a glance and to facilitate comparison of two or more solutions in an easily understandable way.     

基于高光谱成像技术的多宝鱼肉冷藏时间的可视化研究

提出了一种应用可见-近红外高光谱成像技术快速无损检测多宝鱼肉冷藏时间并实现其可视化的新方法。采集8种不同冷藏时间的共160个鱼肉样本的高光谱图像,并提取样本感兴趣区域(ROI)的平均光谱。取120个建模集样本的光谱数据与其相应的冷藏时间建立偏最小二乘回归(PLSR)模型,对40个预测集样本的冷藏时间进行预测,预测决定系数(R2)为0.966 2,预测均方根误差(RMSEP)为0.679 9 d,获得了满意的预测精度。最后,用所建模型对预测集图像上每个像素点的冷藏时间加以预测,采用IDL图像编程技术将不同的时间用不同的颜色表示,最终以伪彩图的形式实现多宝鱼肉冷藏时间的可视化。结果表明,高光谱成像技术与化学计量学结合可以准确预测鱼肉的冷藏时间,与图像处理方法结合可以实现预测时间的可视化,能形象、直观地展示出鱼肉的新鲜度状态和分布情况,为实现水产品加工的自动化奠定了基础。     

SinaPlot: An Enhanced Chart for Simple and Truthful Representation of Single Observations Over Multiple Classes

Recent developments in data-driven science have led researchers to integrate data from several sources, over diverse experimental procedures, or databases. This alone poses a major challenge in truthfully visualizing data, especially when the number of data points varies between classes. To aid the representation of datasets with differing sample size, we have developed a new type of plot overcoming limitations of current standard visualization charts. SinaPlot is inspired by the strip chart and the violin plot and operates by letting the normalized density of points restrict the jitter along the x-axis. The plot displays the same contour as a violin plot but resembles a simple strip chart for a small number of data points. By normalizing jitter over all classes, the plot provides a fair representation for comparison between classes with a varying number of samples. In this way, the plot conveys information of both the number of data points, the density distribution, outliers and data spread in a very simple, comprehensible, and condensed format. The package for producing the plots is available for R through the CRAN network using base graphics package and as geom for ggplot through ggforce. We also provide access to a web-server accepting excel sheets to produce the plots (http://servers.binf.ku.dk:8890/sinaplot/).     

Studying disturbance waves in vertical annular flow with high-speed video

In many annular two-phase gas–liquid flows, large disturbance waves propagate liquid mass. These waves are important for modeling of gas-to-liquid momentum transfer and liquid film behavior. High-speed videos of vertical upflow have been analyzed to extract individual and average wave data. Two types of structures, coherent waves and piece waves, have been identified in these flows. Velocities, lengths, and temporal spacings of individual waves and average velocities, lengths, frequencies, and intermittencies have been studied as functions of both gas and liquid flow rates. Velocity and frequency increase with liquid and gas flow rates, length decreases with increasing gas flow and increases with increasing liquid flow, and intermittency is predominantly an increasing function of liquid flow.     

两级烟气废热热管溴化锂制冷机的可视化设计

根据国内外有关资料与作者拟合的公式,采用Visual basic面向对象的编程技术,对两级烟气废热热管溴化锂制冷机进行了计算机辅助设计研究,并编制了可视化程序,适用于工程上对该系统的设计与计算,缩短设计时间,提高工作效率。     

Methods for the visualization of clustered climate data

Summary  Increasing amounts of large climate data require new analysis techniques. The area of data mining investigates new paradigms and methods including factors like scalability, flexibility and problem abstraction for large data sets. The field of visual data mining in particular offers valuable methods for analyzing large amounts of data intuitively. In this paper we describe our approach of integrating cluster analysis and visualization methods for the exploration of climate data. We integrated cluster algorithms, appropriate visualization techniques and sophisticated interaction paradigms into a general framework.