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1

An integrated approach to estimate storage reliability with masked data from series system

Zhang Yongjin, Zhao Ming

Eksploatacja i Niezawodność

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2023

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Vol. 25, no. 4

art. no. 172922

EN

Storage reliability is of importance for the products that largely stay in storage in their total life-cycle such as warning systems for harmful radiation detection, and many kinds of defense systems, etc. Usually, the field-testing data can be available, but the failure causes for a series system cannot be always known because of the masked information. In this paper, the storage reliability model with possibly initial failures is studied on the statistical analysis method when the masked data are considered. To optimize the use of the masked survival data from storage systems, a technique based on the least squares (LS) method with an EM-like algorithm, is proposed for the series system. The parametric estimation procedure based on the LS method is developed by applying the algorithm to update the testing data, and then the LS estimation for the initial reliability and failure rate of the components constituting the series system are investigated. In the case of exponentially distributed storage lifetime, a numerical example is provided to illustrate the method and procedure. The results should be useful for accurately evaluating the production reliability, identifying the production quality, and planning a storage environment.

2

Research on art design of urban wetland park planning based on the concept of sustainable development

Zhou Zhenhong, Wang Shiqi, Zhao Ming, Zhi Fei

Ecological Chemistry and Engineering. S

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2023

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Vol. 30, nr 2

175--181

EN

With the development of the social economy, the scale of cities has expanded rapidly, and the urban ecological imbalance has become increasingly severe, which has caused many urban problems. People gradually realise that cities and human beings develop more harmoniously and healthily by building and developing cities on the basis of natural ecology and seeking the harmonious coexistence of ecology and humanity. The results of the sustainable landscape ecological evaluation of Anhui Shilonghu National Wetland Park show that the park has good ecological, social, and economic benefits and functions. The urban ecological environment and social and economic development have a good supporting effect on the park, and its overall evaluation grade is good. Compared with other waterscape parks, the ecological function of urban wetland parks is the most basic and essential function of the landscape. It has multiple functions, such as popular science education and being close to nature and entertainment. Developing wetland ecological experience tourism activities benefits wetland protection and ecologically coordinated, sustainable development. It can also comprehensively improve wetland parks’ ecological, social, and economic benefits.

3

Prediction of PM2.5 hourly concentrations in Beijing based on machine learning algorithm and ground-based LiDAR

Fang Zhiyuan, Yang Hao, Li Cheng, Cheng Liangliang, Zhao Ming, Xie Chenbo

Archives of Environmental Protection

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2021

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Vol. 47, no. 3

98--107

EN

The prediction of PM2.5 is important for environmental forecasting and air pollution control. In this study, four machine learning methods, ground-based LiDAR data and meteorological data were used to predict the ground-level PM2.5 concentrations in Beijing. Among the four methods, the random forest (RF) method was the most effective in predicting ground-level PM2.5 concentrations. Compared with BP neural network, support vector machine (SVM), and various linear fitting methods, the accuracy of the RF method was superior by 10%. The method can describe the spatial and temporal variation in PM2.5 concentrations under different meteorological conditions, with low root mean square error (RMSE) and mean square deviation (MD), and the consistency index (IA) reached 99.69%. Under different weather conditions, the hourly variation in PM2.5 concentrations has a good descriptive ability. In this paper, we analyzed the weights of input variables in the RF method, constructed a pollution case to correspond to the relationship between input variables and PM2.5, and analyzed the sources of pollutants via HYSPLIT backward trajectory. This method can study the interaction between PM2.5 and air pollution variables, and provide new ideas for preventing and forecasting air pollution.