United friction resistance in open channel flows

It is now over half a century since Keulegan conducted his open channel flow experiments.Over the past decades,many empirical formulae were proposed based on his results,however,there is still not a combined expression to describe the effects of friction over all hydraulic regions in open channel flows.Therefore,in this letter,based on the analysis of the implicit model and the logarithmic matching method,the results of Keulegan(for authentic experiment data are no longer available,here we adopt the analytical solutions given by Dou)are rescaled into one monotone curve by combining the Reynolds number and the relative roughness of the river bed.A united expression that could cover the entire turbulence regions and be validated with Dou’s analytical solutions is suggested to estimate the friction factor throughout the turbulent region in open channel flows,with higher accuracy than that of the previous formulas.     

Detection of occupancy profile based on carbon dioxide concentration pattern matching

Occupancy is one of major factors influencing indoor microclimate. The aim of this work was to determine the influence of this factor on indoor air quality (IAQ) on the basis of CO₂ concentration measurements and statistical analysis. We wanted to identify periods of time when IAQ was strongly affected by the occupancy described by the given profile. The proposed approach consisted of several stages. The CO₂ concentration was measured and recorded in the form of univariate time series. Then, the relationship between occupancy and internal structure of the time series was disclosed. There were distinguished segments based on sample periodogram. Each segment was associated with a particular occupancy profile. In order to detect how human factor represented by a given occupancy profile influences IAQ we proposed to use pattern matching. In this approach there was examined the similarity between segments of the time series and the pattern of CO₂ variability, which represented a selected occupancy profile. The analysis was performed in time domain using moving time window technique. The similarity was judged based on two types of indexes, namely correlation coefficients and distance measures. It was shown that our approach may be applied to successfully detect a particular occupancy profile. The best performance was achieved when using angular distance as the similarity index. In this case we reached 82% true positive and 22% false positive detections. The proposed method may be applied in diagnostics problems to reveal sources of indoor air quality problems.     

A cooperative net zero energy community to improve load matching

The work reported here addresses load matching improvement in Net Zero Energy Buildings (Net-ZEBs). The related relevant literature shows that currently research work is mainly focused on improving the load matching of individual buildings. In this paper the concept of a Cooperative Net Zero Energy Community (CNet-ZEC) is introduced, extending discussion to the enhancement of load matching at a wider community level. Both building and community levels are compared in order to assess the work proposed here, through the analysis of three distinct scenarios where five Net-ZEBs work individually or in community.The results presented here were obtained through a detailed simulation based on 1-min resolution stochastic load profiles and recorded weather data. The results indicate that over the period of a year the CNet-ZEC has the potential to increase the electrical demand covered by onsite electricity generation up to 21% and the on-site generation that is used by the building up to 15%. The following elements are considered by the CNet-ZEC in order to produce those results: (i) demand heterogeneity of the buildings integrating the community; (ii) the higher number of controllable devices; and (iii) the potential higher amount of energy available to satisfy the community demand.     

Quality assessment for color correction-based stitched images via bi-directional matching

With the deepening of social information, the panoramic image has drawn a significant interest of viewers and researchers as it can provide a very wide field of view (FoV). Since panoramic images are usually obtained by capturing images with the overlapping regions and then stitching them together, image stitching plays an important role in generating panoramic images. In order to effectively evaluate the quality of stitched images, a novel quality assessment method based on bi-directional matching is proposed for stitched images. Specifically, dense correspondences between the testing and benchmark stitched images are first established by bi-directional SIFT-flow matching. Then, color-aware, geometric-aware and structure-aware features are respectively extracted and fused via support vector regression (SVR) to obtain the final quality score. Experiments on our newly constructed database and ISIQA database demonstrate that the proposed method can achieve comparable performance compared with the conventional blind quality metrics and the quality metrics specially designed for stitched images.     

DEM: Deep Entity Matching Across Heterogeneous Information Networks

Heterogeneous information networks, which consist of multi-typed vertices representing objects and multi-typed edges representing relations between objects, are ubiquitous in the real world. In this paper, we study the problem of entity matching for heterogeneous information networks based on distributed network embedding and multi-layer perceptron with a highway network, and we propose a new method named DEM short for Deep Entity Matching. In contrast to the traditional entity matching methods, DEM utilizes the multi-layer perceptron with a highway network to explore the hidden relations to improve the performance of matching. Importantly, we incorporate DEM with the network embedding methodology, enabling highly efficient computing in a vectorized manner. DEM’s generic modeling of both the network structure and the entity attributes enables it to model various heterogeneous information networks flexibly. To illustrate its functionality, we apply the DEM algorithm to two real-world entity matching applications: user linkage under the social network analysis scenario that predicts the same or matched users in different social platforms and record linkage that predicts the same or matched records in different citation networks. Extensive experiments on real-world datasets demonstrate DEM’s effectiveness and rationality.

     

基于线特征及迭代最近点算法的地基建筑物点云自动配准方法

为克服迭代最近点(ICP)算法易陷入局部最优的缺陷，提出一种基于线特征及ICP算法的地基建筑物点云自动配准方法。首先，基于法向一致性进行建筑物点云平面分割；接着，采用alpha-shape算法进行点簇轮廓线提取，并拆分和拟合处理得到特征线段；然后，以线对作为配准基元，以线对夹角和距离作为相似性测度进行同名特征匹配，实现建筑物点云的粗配准；最后，以粗配准结果为初值，进一步采用ICP算法完成点云精确配准。利用两组部分重叠的建筑物点云进行配准实验，实验结果表明，采用由粗到精的配准方法能有效改善ICP算法对初值依赖的问题，实现具有部分重叠的建筑物点云的有效配准。     

Hand gesture recognition using valley circle feature and Hu’s moments technique for robot movement control

Hand gesture recognition is a simpler and more natural way of human computer interaction. The goal of this paper is to detect the continuous gestures and use them to convey information for the robot movement control. So the hand gesture recognition requires fast and extremely robust. In this paper, three strategies were used to realize the hand gesture recognition: (1) the valley circle (VC) was created for the first stage of 6 fingertip numbers classification; (2) the hybrid feature vector of Hu’s moments, convexity and compactness (HCC) were constructed for the second stage of gesture recognition of the remainder unknown gesture classes; (3) a new template matching recognition (NTMR) algorithm was proposed to realize 10 gesture classes recognition. To test the hand gesture recognition method, the robot movement control system was built. It is experimental proved that the NTMR algorithm is effective and corrective for the hand gesture recognition. It increased the recognition accuracy by 4% and decreased the recognition duration by 112 ms compared with Hu’s moment method. It had good performances of the real-time hand gesture acquisition and information conveyance, and it had the invariant properties when the gesture was rotated and shifted and scaled.     

A new projection-based iterative image reconstruction algorithm for dual-energy computed tomography

Dual-energy CT can be represented as the dual-energy equations by decomposing the linear attenuation coefficient of the X-ray scanned object into two material basis functions of photoelectric absorption and Compton scatter. To solve the dual-energy equations, in this paper, we apply the mean-value theorem for integrals and propose a new projection-based iterative algorithm. We discuss the convergence of the proposed algorithm and carry out various numerical simulations for demonstrating its feasibility.     

SDMSim: A manufacturing service supply–demand matching simulator under cloud environment

Nowadays, with the introduction and application of new information technologies in manufacturing, various advanced manufacturing modes and national strategies have been put forward and paid more and more attention, such as Industry 4.0, Industrial Internet, Cyber-Physical System or Cyber Manufacturing, Made in China 2025, Internet Plus Manufacturing, Cloud Manufacturing, etc. For these modes and strategies, how to realize the effective and intelligent supply–demand matching (SDM) of various manufacturing resources and capabilities (MR&C) in the form of service is one of the common issues and aims. In order to provide a uniformed research platform for related researchers both in academic and industry, the concept of manufacturing service SDM simulator (SDMSim) is proposed in this paper. A hypernetwork based architecture for the simulator is designed, as well as its seven key functions and subsystems, including manufacturing service management, manufacturing task management, manufacturing service SDM hypernetwork, manufacturing service SDM problem formulation and configuration, matching and scheduling algorithms/strategies selection and design, statistical analysis, and visualization. It illustrates that SDMSim has the potential to serve the users of manufacturing service provider, manufacturing service consumer, manufacturing service operator in the field of SoM, as well as the related researchers.     

Preconditioned rotated iterative methods in the solution of elliptic partial differential equation

A second-order finite difference scheme derived from rotated discretisation formula is employed in conjunction with a preconditioner to obtain highly accurate and fast numerical solution of the two-dimensional elliptic partial differential equation. The use of a ‘splitting’ preconditioning strategy will be shown to improve the spectral properties of the matrix of the linear system resulting from this discretisation by minimising the eigenvalue spectrum of the transformed matrix. The application of this technique to several acceleration iterative methods, such as Simultaneous displacement, Richardson's and Chebyshev accelerated methods, are presented and discussed.