Metrics for Quantifying the Similarities and Differences between IFC Files

Recently, several papers reported problems in data exchange using industry foundation classes (IFC). However, most comparisons were made based on a visual check, a manual count, and observation of properties that were selectively chosen. This study proposes a set of metrics for quantifying the similarities and differences between IFC files. The proposed metrics include the similarity rate, the matching rate, the globally unique identifier (GUID) preservation rate, the missing rate, and the addition rate. A long-term goal of this study is to develop a set of metrics for quantifying the information exchange rate between two IFC files. Automated identification of modified information versus newly generated information is an unsolved challenge. The proposed metrics were used in analyzing 88 IFC files generated from different systems to demonstrate the potential use of the proposed metrics.     

基于人类视觉系统的立体图像质量评价方法

随着立体图像的大规模发展,很多应用场合需要能够迅速有效地完成对立体图像的质量评价工作,以便于后续应用,而对其进行主观质量评价在效率上很难满足要求。因此,提出了一种感知质量评价算法,并结合了一些人类视觉系统的特性。首先需要得到视差图,然后通过边界图和显著图来对视差图进行加权调整。接着使用Minkowski融合方法将加权后的视差图整合成感知分数。最后,使用多尺度分析来得到最终的感知质量分数。通过使用EPFL立体质量评价数据库来验证文中的立体图像感知质量评价算法。实验显示算法最后得到的客观分数和EPFL数据库中的主观分数具有高度的一致性和单调性,证明了文中的立体图像感知质量评价算法是有效的。     

Satellite-Based Energy Balance for Mapping Evapotranspiration with Internalized Calibration (METRIC)—Applications

Recent satellite image processing developments have provided the means to calculate evapotranspiration (ET) as a residual of the surface energy balance to produce ET “maps.” These ET maps (i.e., images) provide the means to quantify ET on a field by field basis in terms of both the rate and spatial distribution. The ET images show a progression of ET during the year or growing season as well as its spatial distribution. The mapping evapotranspiration at high resolution with internalized calibration (METRIC) is a satellite-based image-processing procedure for calculating ET. METRIC has been applied with high resolution Landsat images in southern Idaho, southern California, and New Mexico to quantify monthly and seasonal ET for water rights accounting, operation of ground water models, and determination of crop coefficient populations and mean curves for common crops. Comparisons between ET by METRIC, ET measured by lysimeter, and ET predicted using traditional methods have been made on a daily and monthly basis for a variety of crop types and land uses. Error in estimated growing season ET was 4% for irrigated meadow in the Bear River basin of Idaho and 1% for an irrigated sugar beet crop near Kimberly, Id. Standard deviation of error for time periods represented by each satellite image averaged about 13 to 20% in both applications. The results indicate that METRIC and similar methods such as SEBAL hold substantial promise as efficient, accurate, and inexpensive procedures to estimate actual evaporation fluxes from irrigated lands throughout growing seasons.     

提高大视场测量相机干板成象能力的方法研究

随着飞行体材料的改进 ,再入段摩擦发光的强度越来越弱 ,致使接受介质干板的成象质量越来越差 ,甚至不能判读处理。利用干板药膜的感光特性曲线 ,在某一范围内 ,其曝光量与曝光温度成线性关系的理论 ,根据试验落区的具体特点 ,提出通过温度控制来调整和改善曝光效果的方法 ,以及使用该方法存在的一系列需要克服的问题 ,使处于临界状态下的目标轨迹清晰可辨 ,便于事后能够判读处理 ,从而提高落区试验成功率。     

The Omni-family of all-purpose access methods: a simple and effective way to make similarity search more efficient

Similarity search operations require executing expensive algorithms, and although broadly useful in many new applications, they rely on specific structures not yet supported by commercial DBMS. In this paper we discuss the new Omni-technique, which allows to build a variety of dynamic Metric Access Methods based on a number of selected objects from the dataset, used as global reference objects. We call them as the Omni-family of metric access methods. This technique enables building similarity search operations on top of existing structures, significantly improving their performance, regarding the number of disk access and distance calculations. Additionally, our methods scale up well, exhibiting sub-linear behavior with growing database size.     

A unified approach to pattern recognition

The paper is an outline of a new approach to pattern recognition developed by the author. A fuller introduction to the approach will appear soon.⁽¹⁾ Within the proposed framework the two principal approaches to pattern recognition—vector and syntactic—are unified.     

基于三元采样图卷积网络的半监督遥感图像检索

该文提出了一种基于三元采样图卷积网络的度量学习方法,以实现遥感图像的半监督检索。所提方法由三元图卷积网络(TGCN)和基于图的三元组采样(GTS)两部分组成。TGCN由3个具有共享权重的并行卷积神经网络和图卷积网络组成,用以提取图像的初始特征以及学习图像的图嵌入。通过同时学习图像特征以及图嵌入,TGCN能够得到用于半监督图像检索的有效图结构。接着,通过提出的GTS算法对图结构内隐含的图像相似性信息进行评价,以选择合适的困难三元组(Hard Triplet),并利用困难三元组组成的样本集合对模型进行有效快速的模型训练。通过TGCN和GTS的组合,提出的度量学习方法在两个遥感数据集上进行了测试。实验结果表明,TGCN-GTS具有以下两方面的优越性：TGCN能够根据图像及图结构学习到有效的图嵌入特征及度量空间;GTS有效评估图结构内隐含的图像相似性信息选择合适的困难三元组,显著提升了半监督遥感图像检索效果。     

弯扭斜交网格结构参数化设计中的几何学理论与方法

从2008年北京奥运会主场馆鸟巢开始,国内出现了一批弯扭斜交网格结构造型的建筑,其中最具代表的是北鸟巢南春茧和北京凤凰国际中心。弯扭斜交网格结构以其优美而独特造型深受建筑师青睐。本文将几何学理论联系工程实际,给出了两种用于弯扭斜交网格结构参数化设计的几何方法。其一,用微分几何方法对弯扭斜交网格结构几何形体进行分析,给出其表面所在曲面参数方程的分析表达。其二,用运动学的观点,通过活动标架、扫掠及放样等造型方法,利用计算机辅助图形学方法得到弯扭斜交网格结构几何模型。两种方法的有效性通过2022年杭州亚运会乒乓球馆设计实践得到了验证。       

Reliability of force–time curve characteristics during maximal isometric leg press in differently trained high-level athletes

The aim of this research was to establish the metrologic values of the isometric force–time characteristics of leg extensors in differently trained, healthy male athletes and non-athletes. 99 subjects performed a standardized “isometric leg press” test. Even though the results showed a high statistical significance in terms of representativeness, generalizability and reliability for all contractile characteristics of observed measured variables, different methodological approaches were required in order to obtain the most valid results for differently trained and untrained subjects. Based on the results obtained, and from the aspect of the methodology of testing different isometric force characteristics, it was possible to conclude that the standardization of the isometric leg press requires two trials in football, where the most reliable data was from the first trial (the communality rates (H²) from 0.866 to 0.969). Water polo and basketball require three trials. The most reliable data was from the third and second trial in water polo (H² from 0.909 to 0.986). In basketball the most reliable data was from the second trial (H² from 0.824 to 0.987). The untrained healthy adult population requires four trials, and the most reliable data was from the third trial (H² from 0.961 to 0.995).