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Background: Pemphigus vulgaris is a life-threatening autoimmune bullous disease characterized by flaccid blister formation. As there has been no macroscopic assessment of epidemiological characteristics, its disease burden in the general population remains unknown. Objectives: To assess the global incidence rate of pemphigus vulgaris in the general population. Methods: The search was conducted in databases including Medline, Embase, Web of Science, and The Cochrane Library from inception to May 1st, 2022. We included original studies that either reported incidence of pemphigus vulgaris or provided raw data for calculating. Studies based on a specific population instead of the general population were excluded. Individual studies were summarized using random-effects mode. The pooled incidence rate of pemphigus vulgaris among the general population and subgroups were obtained. Heterogeneity (I2 statistic) was assessed with the χ2 test on Cochrane’s Q statistic. Results: 29 studies were eligible for final analysis and the pooled incidence rate of pemphigus vulgaris was 2.83 per million person-years (95%CI, 2.14-3.61). The incidence rate was similar between men and women and remained stable in the past half-century. Southern Asia showed the highest rate among subcontinents that had more than one study conducted as 4.94 per million person-years (95%CI, 2.55-8.10). Economic levels do not seem to have any bearing on incidence. Conclusions: Despite the substantial heterogeneity among studies, this meta-analysis revealed the worldwide incidence rate of pemphigus vulgaris for the first time and may assist in assessing global disease burden and promoting health policy.

To better analyze and process power data to obtain effective information, a power big data analysis scheme based on Hadoop architecture is proposed. We analyze the cloud computing environment Hadoop distributed platform to obtain massive data of large-scale distributed power system. According to the characteristics of intelligent power consumption data, common data mining algorithm modules such as parallel classification algorithm and parallel real-time clustering algorithm are designed, and the implementation of clustering algorithm with different principles is further analyzed. Then, HBase is adopted to access data in a distributed way, and MapReduce is used to realize the visual management of power GIS data. The experimental results show that the parallel processing method of power big data based on Hadoop has high efficiency and good scalability, and the algorithm has good identification ability for massive data in the cluster mode.

To ensure the safe and stable operation of the power grid system and strengthen the refined management level of the State Grid Corporation of China, a grid operation big data association analysis model based on Apriori association algorithm is proposed. This paper discusses the logic framework of the power big data platform, and describes the specific implementation from the functional architecture, technical architecture and other aspects. Aiming at the problem of massive heterogeneous power data and low sharing degree, the transaction matrix is pruned and compressed by setting the minimum support degree and establishing the frequent set matrix, and the implementation process of the improved algorithm on the MapReduce programming model of Hadoop platform is provided. Based on the research of Spark programming model, the improved algorithm is implemented in parallel style. The experimental results show that the efficiency of the algorithm after parallel processing has been greatly improved, which can also effectively improve the calculation amount and efficiency of power big data.

The aim of this paper is to report the design and development of an active suspension electronic controller, which is based on a microcontroller unit (MCU). This controller includes an input module, processing module, output module, communication module and interface module. Appropriate hardware and software is designed. The controller has the characteristics of indicating control status, communicating with the PC and being conveniently operated. It has the functions of controlling the static height and vibration of the suspension. Simulations and experimental results demonstrate that the controller can meet the control requirements of an active suspension system.