Clustering Scatter Plots Using Data Depth Measures.

Clustering is rapidly becoming a powerful data mining technique, and has been broadly applied to many domains such as bioinformatics and text mining. However, the existing methods can only deal with a data matrix of scalars. In this paper, we introduce a hierarchical clustering procedure that can handle a data matrix of scatter plots. To more accurately reflect the nature of data, we introduce a dissimilarity statistic based on "data depth" to measure the discrepancy between two bivariate distributions without oversimplifying the nature of the underlying pattern. We then combine hypothesis testing with hierarchical clustering to simultaneously cluster the rows and columns of the data matrix of scatter plots. We also propose novel painting metrics and construct heat maps to allow visualization of the clusters. We demonstrate the utility and power of our new clustering method through simulation studies and application to a microbe-host-interaction study

Growing small-world networks based on a modified BA model

We propose a simple growing model for the evolution of small-world networks. It is introduced as a modified BA model in which all the edges connected to the new nodes are made locally to the creator and its nearest neighbors. It is found that this model can produce small-world networks with power-law degree distributions. Properties of our model, including the degree distribution, clustering, and the average path length are compared with that of the BA model. Since most real networks are both scale-free and small-world networks, our model may provide a satisfactory description for empirical characteristics of real networks.Comment: 4 pages, 4 figure

Study on the characteristics of gas permeability of coal under loaded stress

The #3 coal seam of Jinsheng Rundong Ltd. of Jin-Coal Group in Shanxi Province, China, has high gas content and pressure; however, it has a low gas permeability, which can easily cause gas enrichment and may cause accidents of coal and gas outbursts. In this work, the characteristics of gas seepage were thoroughly studied by designing and modifying the ‘complete stress-strain tri-axial servo temperature-controlled test system’. The study was conducted based on four factors: Axial pressure, confining pressure, effective stress and gas pressure. We found that the axial pressure has a weak impact on coal gas permeability, indicated by a linear relationship. The confining pressure, however, has a strong impact on gas permeability, showing an exponential relationship. The relationship between permeability and gas pressure was identified as a second-order polynomial function. The functional relationship between gas permeability and axial pressure, confining pressure, effective stress, gas pressure was analyzed. Investigation into the natural flow rate of gas, concentration of gas drainage and damping coefficient supported the conclusion from the experimental study on the characteristics of gas seepage under loaded stress

Robust global sliding model control for water-hull-propulsion unit interaction systems - part 2: model validation

Unexpected severe hull deformation caused by wave loads poses alignment problem to the propulsion shaft line in large scale ships, which would significantly influence the dynamical performance of the marine propulsion system. How to suppress negative disturbance imposed by the interaction between water-hull-propulsion and ensure the normal operation of the marine propulsion system is a challenging task. To address this issue, a new global sliding model control (GSMC) for marine water-hull-propulsion unit systems is proposed and investigated to obtain more accurate control performance in a series of researches. In Part 1 the GSMC controller has been developed and the bounded nonlinear model uncertainties have been derived based on the experiments and sea trial. In this work the upper boundary of 1,85 % was introduced into the GSMC controller to derive the total control law realising the robust control of the marine propulsion system. Numerical simulations based on the real bulk carrier parameters show a high effectiveness of the GSMC for speed tracking, compared with the traditional sliding model controller and Proportional Integral Derivative (PID) controller. By the proposed and investigated control system in this paper may be developed a simple practical-effective robust control strategy for marine propulsion systems subject to some complex unknown uncertainties through further investigations, validations and modification

Risk Management of Road Engineering Project Based on Analytic Hierarchy Process

In the construction process of road engineering, risks are everywhere. To do a good job in the risk management of road engineering projects, finding the risk factors of road engineering projects is an important part of it. This article introduces the characteristics of project risks and the process of risk management. The AHP method is applied to the risk analysis of road engineering projects to realize the ranking of risk factors, the evaluation of the total risk system, and the selection of risk response measures. This article conducts risk evaluation on the project, finds out important risk factors, and effectively controls them. This paper adopts the analytic hierarchy process on the overall risk management of road engineering projects. Finally, it comprehensively considers the systemic and non-systematic risks faced by road engineering, and specifically involves macro policy and economic risks, as well as project initiation and project construction. The risks and capital risks, and other links considered the internal and external factors of the road-engineering project. In this way, the project risk has been comprehensively measured by a combination of qualitative and quantitative methods, and the effective management of the project has been finally realized

Research on Bridge Structural Health Assessment Based on Finite Element Analysis

In view of the content of bridge condition assessment and health monitoring, this paper is based on the finite element simulation analysis. The uncertain finite element model updating method based on sequential optimization strategy is studied, and the uncertain modal parameter data obtained by health monitoring system are applied to upgrade the uncertain finite element model of cable-stayed bridges, which provides a more accurate finite element model for subsequent reliability analysis. Firstly, the finite element dynamic analysis of the main span structure of the bridge is carried out, and the natural frequencies and modes are obtained. Then the measured natural frequencies of the structure are obtained by estimating the power spectrum of the dynamic monitoring data, and the theoretical values are compared with the measured ones. The dynamic characteristics of the modified two-stayed bridge finite element model are verified by the load test results. The results show that the modified finite element model can simulate the dynamic characteristics of the actual structure well. Most of the measured and calculated displacement increments were within the margin of error. The error is within 5%, which can accurately reflect the true stress state of the structure. The uncertainty model based on the sequential optimization strategy is simple and can be applied to the uncertainty of the finite element model of the actual bridge structure