Global-Scale Resource Survey and Performance Monitoring of Public OGC Web Map Services

One of the most widely-implemented service standards provided by the Open Geospatial Consortium (OGC) to the user community is the Web Map Service (WMS). WMS is widely employed globally, but there is limited knowledge of the global distribution, adoption status or the service quality of these online WMS resources. To fill this void, we investigated global WMSs resources and performed distributed performance monitoring of these services. This paper explicates a distributed monitoring framework that was used to monitor 46,296 WMSs continuously for over one year and a crawling method to discover these WMSs. We analyzed server locations, provider types, themes, the spatiotemporal coverage of map layers and the service versions for 41,703 valid WMSs. Furthermore, we appraised the stability and performance of basic operations for 1210 selected WMSs (i.e., GetCapabilities and GetMap). We discuss the major reasons for request errors and performance issues, as well as the relationship between service response times and the spatiotemporal distribution of client monitoring sites. This paper will help service providers, end users and developers of standards to grasp the status of global WMS resources, as well as to understand the adoption status of OGC standards. The conclusions drawn in this paper can benefit geospatial resource discovery, service performance evaluation and guide service performance improvements.Comment: 24 pages; 15 figure

AI based Robot Safe Learning and Control

Introduction This open access book mainly focuses on the safe control of robot manipulators. The control schemes are mainly developed based on dynamic neural network, which is an important theoretical branch of deep reinforcement learning. In order to enhance the safety performance of robot systems, the control strategies include adaptive tracking control for robots with model uncertainties, compliance control in uncertain environments, obstacle avoidance in dynamic workspace. The idea for this book on solving safe control of robot arms was conceived during the industrial applications and the research discussion in the laboratory. Most of the materials in this book are derived from the authors’ papers published in journals, such as IEEE Transactions on Industrial Electronics, neurocomputing, etc. This book can be used as a reference book for researcher and designer of the robotic systems and AI based controllers, and can also be used as a reference book for senior undergraduate and graduate students in colleges and universities

The radiation protection role of heparin-SOD conjugate in irradiated mice

Heparin-SOD conjugate (Hep-SOD) was prepared by modifying Cu,Zn-SOD with heparin. An acute radiation-induced mouse injury model was constructed to study the radiation protection effects of Hep-SOD conjugate. Fifty-six mice were randomly divided into seven groups: (I) normal control group; (II) irradiated control group; (III) positive control group (amifostine group, 300 mg/kg); (IV) SOD group (35000 U/kg); (V) high dosage of Hep-SOD group (70000 U/kg); (VI) medium dosage of Hep-SOD group (35000 U/kg); (VII) low dosage of Hep-SOD group (17500 U/kg). Drugs were intraperitoneally injected into each mouse 1 h before radiation except for the normal control group. All the irradiated groups were irradiated with 6 Gy. Organ indices, haematopoietic function indices, peripheral blood cells, liver function test, oxidative stress state and pathological observation were detected to study the effects of Hep-SOD on irradiated mice. Results showed that bone marrow suppression of irradiated mice could be reduced when treated by Hep-SOD before radiation. Oxidative stress detection and pathological observation of the liver and intestine showed that the damage caused by radiation was relieved when mice were treated with Hep-SOD before radiation. This study shows a new direction to prevent organisms from the damage caused by radiation

Ten-year changes in the prevalence of overweight, obesity and central obesity among the Chinese adults in urban Shanghai, 1998–2007 — comparison of two cross-sectional surveys

BACKGROUND: In China, obesity is expected to increase rapidly in both urban and rural areas. However, there have been no comprehensive reports on secular trends in obesity prevalence among Chinese adults in urban Shanghai, which is the largest city in southern China. METHODS: In 1998–2001 and again in 2007–2008, two independent population-based cross-sectional surveys were conducted in Shanghai to investigate the prevalence of metabolic disorders. These surveys obtained height, waist circumference (WC), and weight measurements for Chinese adults aged between 20 and 74 years who lived in urban communities. From the 1998–2001 survey, 4,894 participants (2,081 men and 2,813 women, mean age: 48.9 years) were recruited, and 4,395 participants (1,599 men and 2,796 women, mean age: 49.8 years) were recruited from the 2007–2008 survey. Using the World Health Organization criteria, overweight was defined as 25 kg/m(2) ≤ BMI < 30 kg/m(2) and obesity as BMI ≥ 30 kg/m(2). Central obesity was defined as WC ≥ 90 cm in men or ≥85 cm in women. The differences in prevalence of obesity, central obesity and overweight between the two surveys were tested using multivariable logistic regression analyses. RESULTS: Compared to the 1998–2001 survey, in the 2007–2008 survey the BMI distribution for men and the WC distribution for both genders is shifted significantly to the right along the x-axis (all p < 0.001). Over the ten years, the prevalence of combined overweight and obesity increased 24% (from 31.5% to 39.1%, p < 0.001) in men, but decreased 8% (from 27.3% to 25.0%; p < 0.01) in women. The prevalence of central obesity increased 40% in men (from 19.5% to 27.3%; p < 0.01), but the increase was not significant in women (15.0% to 17.1%; p = 0.051). In the total population, only central obesity showed a significant change between the populations in the two surveys, increasing 29% (from 17.3% to 22.4%; p < 0.001). CONCLUSIONS: Over this 10 year period, central obesity increased significantly in the Shanghai adult population. However, the prevalence of combined overweight and obesity was significantly increased in men but not in women

Analysis of the current status of tuberculosis transmission in China based on a heterogeneity model

Tuberculosis (TB) is an infectious disease transmitted through the respiratory system. China is one of the countries with a high burden of TB. Since 2004, an average of more than 800,000 cases of active TB have been reported each year in China. Analyzing the case data from 2004-2018, we find significant differences in TB incidence by age group. Therefore, the effect of age heterogeneous structure on TB transmission needs further study. We develop a model of TB to explore the role of age heterogeneity as a factor in TB transmission. The model is fitted numerically using the nonlinear least squares method to obtain the key parameters in the model, and the basic reproduction number Rv 0.8017 is calculated and the sensitivity anal-ysis of Rv to the parameters is given. The simulation results show that reducing the number of new infections in the elderly population and increasing the recovery rate of elderly patients with the disease could significantly reduce the transmission of tuberculosis. Furthermore the feasibility of achieving the goals of the WHO End TB Strategy in China is assessed, and we obtain that with existing TB control measures it will take another 30 years for China to reach the WHO goal to reduce 90% of the number of new cases by year 2049. However, in theoretical it is feasible to reach the WHO strategic goal of ending tuberculosis by 2035 if the group contact rate in the elderly population can be reduced though it is difficulty to reduce the contact rate.Comment: We think this is a very interesting work that gives a good understanding of the current TB transmission in China and assesses the possibility of China achieving the 2035 TB control target and also explores possible ways for how to prevent and control the TB in Chin

Rigid-body inverse dynamics of a spatial redundantly actuated parallel mechanism constrained by two point contact higher kinematic pairs

This paper presents a comparative study of the rigid-body inverse dynamics of a spatial redundantly actuated parallel mechanism constrained by two point contact higher kinematic pairs (HKPs). Firstly, its constrained motions are analysed comprehensively, then four different models are formulated by the generalized momentum approach and the Lagrange-D'Alembert formulation to explore its inverse dynamics. In each method, the first model is built by employing the method directly to the mechanism. In the second model, the dynamic model of its non-redundantly actuated counterpart free of HKPs is built by this approach first, then the constraints from HKPs are modelled, to finally reach the model of the redundantly actuated parallel mechanism (RAPM) where that of its counterpart is utilised as the core. The four models give rise to equivalent numerical results, and the second model in both methods of the RAPM can alleviate the strong coupling between the parasitic motion variables and degrees of freedom (DOFs), boosting the computational speed as fast as that of its non-redundantly actuated counterpart without simplification or loss of accuracy. The comparisons between the mechanism and its counterpart validate that the HKP constraints greatly increase the computational complexity, and the torques required by the parasitic motions of the end effector are significantly smaller than those by the corresponding DOFs