monitoring point
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2022 ◽  
Vol 0 (0) ◽  
Author(s):  
Bantayehu Uba Uge ◽  
Yuancheng Guo ◽  
Yunlong Liu

Abstract Ensuring the safety of existing structures is an important issue when planning and executing adjacent new foundation pit excavations. Hence, understanding the stress state conditions experienced by the soil element behind a retaining wall at a given location during different excavation stages has been a key observational modelling aspect of the performance of excavations. By establishing and carrying out sophisticated soil–structure interaction analyses, stress paths render clarity on soil deformation mechanism. On the other hand, column-type soft ground treatment has recently got exceeding attention and practical implementation. So, the soil stress–strain response to excavation-induced disturbances needs to be known as well. To this end, this paper discusses the stress change and redistribution phenomena in a treated ground based on 3D numerical analyses. The simulation was verified against results from a 1 g indoor experimental test conducted on composite foundation reinforced with long and short cement–fly ash–gravel (CFG) pile adjacent to a moving rigid retaining wall. It was observed that the stress path for each monitoring point in the shallow depth undergoes a process of stress unloading at various dropping amounts of principal stress components in a complex manner. The closer the soil element is to the wall, the more it experiences a change in principal stress components as the wall movement progresses; also, the induced stress disturbance weakens significantly as the observation point becomes farther away from the wall. Accordingly, the overall vertical load-sharing percentage of the upper soil reduces proportionally.


2022 ◽  
Vol 2146 (1) ◽  
pp. 012003
Author(s):  
Huawei Hong ◽  
Kaibin Wu ◽  
Yunfeng Zhang

Abstract With the expansion of China’s power grid construction scale, the transmission line span are gradually improved, which also increases the risk of BL stroke on the transmission line. However, the traditional passive BL protection has many problems, such as weak pertinence and high investment cost, which can not meet the needs of social development. KNN can well describe the similarity measure between the two, which can effectively reduce the training samples. SVM can find the best compromise between model complexity and learning ability in small samples, which is a good sample training method. Through KNN - in-depth learning of the historical data of BL activities accumulated in the power grid, a supervised BL early warning model (hereinafter referred to as EWM) of transmission line can be trained. At the same time, the BL strike of transmission line tower (hereinafter referred to as TLT) has complex meteorological conditions, which requires comprehensive confirmation of various monitoring point parameters. Therefore, it is of great significance to study the BL EWM of TLT based on KNN-SVM algorithm. Firstly, this paper analyzes the KNN-SVM algorithm. Then, this paper establishes an EWM. Finally, this paper is verified.


Processes ◽  
2021 ◽  
Vol 10 (1) ◽  
pp. 35
Author(s):  
Ruichuan Li ◽  
Yi Cheng ◽  
Jikang Xu ◽  
Yanchao Li ◽  
Xinkai Ding ◽  
...  

In view of the complicated hydraulic system, the many driving parts and the great load variation in the combine harvester, and on-line monitoring methods of hydraulic actuating parts such as cutting tables, conveyors and threshing drums were studied. By analyzing the working principle of the hydraulic system of the combine harvester, a mathematical model of the hydraulic system of the combine harvester was established; a simulation model for the fault diagnosis of the hydraulic system of the combine harvester was established based on AMESim. The load signal was introduced to simulate the feeding amount, and the simulation test was carried out. According to the simulation analysis results, the best position of each monitoring point was determined. The on-line monitoring system of the hydraulic actuators of the combine harvester was designed by using LabView, which can collect and display the working parameters of the main working parts of a combine harvester in real time, and alarm the user to faulty working conditions. The field experiment results show that the function and precision of the monitoring system completely meet the requirements of field operation condition monitoring of combine harvesters. The accuracy rate of the fault alarm is 96.5%, and the automatic diagnosis time of the fault alarm is less than 1 min and 18 s, which greatly improves the operation efficiency of the combine harvester.


Author(s):  
T. Franz

Abstract Monitoring of indirect and industrial dischargers, respectively, makes an important contribution to the safe and environmentally sound operation of wastewater systems. As a result of local framework conditions, there is a wide range of monitoring practices across Germany. In a benchmarking project, ten sewerage operators and monitoring bodies representing large German cities have collected data on their work and discussed their practices. The results show that the extent of monitoring is between 244 and 1,457 monitoring points per sewer network (given as 15th and 85th percentile). The median value of the specific expense is 689 EUR per monitoring point and year. In relation to the total wastewater fee volume, the median expense is 0.71%. The sub-process ‘sampling’ was examined more closely. By means of detailed process mapping and regression analyses, it can be shown that on-site activities and tours have the largest share of working time (total of 72%) and thus the greatest leverage in optimisation measures. Various examples are given.


Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 293
Author(s):  
Zhipeng Zhu ◽  
Houlin Liu

The pressure fluctuation characteristics of a rim driven propulsion pump are studied by an experimental method firstly, and then its unsteady inner flow is studied by numerical simulation to reveal the generating mechanism of the pressure fluctuation. In the experiment, a monitoring point was set in a downstream region with a distance of 1D (D, Diameter of impeller) to the impeller. The monitoring point’s dominant frequencies within a low frequency band are 1APF (APF, Axial Passing Frequency) and 2APF. In the numerical simulation, the main fluctuation near the impeller region appears at 1BPF (BPF, Blade Passing Frequency) and as the monitoring point moves downstream, the amplitude becomes smaller. The 1BPF fluctuation nearly disappears when the distance exceeds 1D, and the main frequency moves to 1APF and 2APF, which is in good agreement with the experimental results in the low frequency band. The transient velocity, pressure and vorticity distribution were studied to reveal the causes of 1BPF, 1APF and 2APF fluctuation. The main cause of 1BPF is the jet from the tail of the blade and the main cause of 2APF is the movement of a large-scale double vortex structure on both sides of the low-pressure zone. The movement of the vortex group near the wall may be the main cause that induces the 1APF fluctuation.


Machines ◽  
2021 ◽  
Vol 9 (11) ◽  
pp. 288
Author(s):  
Yilei Zhu ◽  
Jinfeng Zhang ◽  
Yalin Li ◽  
Ping Huang ◽  
Hui Xu ◽  
...  

A pressure pulsation experiment of a dishwasher pump with a passive rotation double-tongue volute was carried out and compared with the pressure pulsation of a single-tongue volute and a static double-tongue volute. The pressure pulsation of the three volute models was compared and analyzed from two aspects of different impeller speeds and different monitoring points. The frequency domain and time–frequency domain of pressure pulsation were obtained by a Fourier transform and short-time Fourier transform, respectively. The results showed that the average pressure of each monitoring point on the rotating double-tongue volute was the smallest and that on the single-tongue volute was the largest. When the impeller rotates at 3000 rpm, there were eight peaks and valleys in the pressure pulsation time domain curve of the single-tongue volute, while the double-tongue volute was twice that of the single-tongue volute. Under different impeller speeds, the changing trends of pressure pulsation time and frequency domain curves of static and rotating double-tongue volutes at monitoring point p1 are basically the same. Therefore, a volute reference scheme with passive rotation speed is proposed in this study, which can effectively improve the flow pattern and reduce pressure inside the dishwasher pump, and also provide a new idea for rotor–rotor interference to guide the innovation of dishwashers.


Symmetry ◽  
2021 ◽  
Vol 13 (11) ◽  
pp. 2149
Author(s):  
Haoliang Lan ◽  
Jie Xu ◽  
Qun Wang ◽  
Wei Ding

This paper is devoted to further strengthening, in the current asymmetric information environment, the informed level of operators about network performance. Specifically, in view of the burst and perishability of a packet loss event, to better meet the real-time requirements of current high-speed backbone performance monitoring, a model for Packet Loss Measurement at the access network boundary Based on Sampled Flow (PLMBSF) is presented in this paper under the premise of both cost and real-time. The model overcomes problems such as the inability of previous estimation to distinguish between packet losses before and after the monitoring point, deployment difficulties and cooperative operation consistency. Drawing support from the Mathis equation and regression analysis, the measurement for packet losses before and after the monitoring point can be realized when using only the sampled flows generated by the access network boundary equipment. The comparison results with the trace-based passive packet loss measurement show that although the proposed model is easily affected by factors such as flow length, loss rate, sampling rate, the overall accuracy is still within the acceptable range. In addition, the proposed model PLMBSF, compared with the trace-based loss measurement is only different in the input data granularity. Therefore, PLMBSF and its advantages are also applicable to aggregated traffic.


2021 ◽  
Vol 2021 ◽  
pp. 1-12
Author(s):  
Dingwen Dong

For the subjective limitation of gas sensor calibration in coal mines, a decision-making method for gas sensor calibration under monitoring failure was studied based on the Gauss process regression (GPR) and the correlation analysis of interval numbers. Based on the correlation characteristics of gas monitoring data of each monitoring point in the work face area in coal mine, the initial confidence interval of gas concentration in monitoring failure period was obtained by GPR, and then the confidence interval was further optimized by the correlation analysis of interval numbers. According to the correlation characteristics of monitoring data of each monitoring point, its similarity of dynamic variation tendency was measured by using Euclidean distance of interval numbers, and the optimal confidence interval was determined by calculating the correlation degree of interval numbers. The case study shows that making full use of the effective monitoring information of multiple monitoring points ensures the reliability of the initial confidence interval; the dynamic adjustment of model parameters in correlation analysis of interval number avoids the subjectivity defect of similar methods and further obtains the consistency between interval numbers’ reliability and correlation degree, which can ensure the effectiveness of the application of this method.


Water ◽  
2021 ◽  
Vol 13 (21) ◽  
pp. 3102
Author(s):  
Hu Xu ◽  
Zhenhua Wang ◽  
Wenhao Li ◽  
Qiuliang Wang

Due to their convenience, water measuring structures have become an important means of measuring water in irrigation canal systems However, relevant research on upstream and downstream water-depth monitoring point locations is scarce. Our study aims to determine the functional relationship between the locations of the water-depth monitoring points and the opening width of the sluice. We established 14 trunk-channel and branch-channel hydrodynamic models. The locations of the water-depth monitoring points for the upstream and downstream reaches and their hydraulic characteristics were assessed using a numerical simulation and hydraulic test. The results showed that the locations of the upstream and downstream water-depth monitoring points were, respectively, 16.26 and 15.51 times the width of the sluice. The average error between the calculated flow rate and the simulated value was 14.37%; the average error between the flow rates calculated by the modified and the simulated values was 3.36%. To further verify the accuracy of the modified discharge calculation formula, by comparing the measured values, we reduced the average error of the modified formula by 19.29% compared with the standard formula. This research provides new insights into optimizing water measurements in irrigation canal systems. The results provide an engineering basis for the site selection of water-depth monitoring points that is suitable to be widely applied in the field.


Information ◽  
2021 ◽  
Vol 12 (11) ◽  
pp. 457
Author(s):  
Fang Zhang ◽  
Guiling Sun ◽  
Bowen Zheng ◽  
Liang Dong

This paper designs and implements an energy management system based on the Spring Boot framework. The system mainly includes three layers, which are the data collection layer, the business logic layer, and the display interface layer from bottom to top. The data collection layer is based on the RS-485 electrical standard and the MODBUS communication protocol. The two protocols connect all energy consumption monitoring points into a mixed topology communication network in the enterprise. The programs in the data collection layer poll each energy consumption monitoring point in the network to collect the data and transmit to the business logic layer. The business logic layer is developed on the basis of the Spring Boot framework and mainly includes two parts: the MySQL database and Tomcat server. In the MySQL database, the stored data are horizontally split according to the time column and stored in different data tables. The split of data reduces the load of a single data table and improves the query performance of the database. The Tomcat server is built into the Spring Boot framework to provide a basic environment for system operation. The Spring Boot framework is the core component of the system. It is responsible for collecting, storing, and analyzing data from energy consumption monitoring points, receiving and processing data requests from the display interface layer. It also provides standard data interfaces to the external programs. The display interface layer is developed on the basis of the Vue framework and integrated into the Spring Boot framework. The display layer combines an open-source visualization chart library called ECharts to provide users with a fully functional and friendly human–computer interaction interface. Through the calculation of hardware and software costs, considering the personnel cost in different regions, the total cost of the energy management system can be estimated. The cost of construction was approximately 210,000 USD in this paper. Since the system was actually deployed in a manufacturing company in December 2019, it has been operating stably for more than 600 days.


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