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Date submitted2023-07-27
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Date accepted2024-06-03
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Date published2024-12-25
Normalized impulse response testing in underground constructions monitoring
Impulse Response testing is a widespread geophysical technique of monolithic plate-like structures (foundation slabs, tunnel lining, and supports for vertical, inclined and horizontal mine shafts, retaining walls) contact state and grouting quality evaluation. Novel approach to data processing based on normalized response attributes analysis is presented. It is proposed to use the energy of the normalized signal calculated in the time domain and the normalized spectrum area and the average-weighted frequency calculated in the frequency domain as informative parameters of the signal. The proposed technique allows users a rapid and robust evaluation of underground structure’s grouting or contact state quality. The advantage of this approach is the possibility of using geophysical equipment designed for low strain impact testing of piles length and integrity to collect data. Experimental study has been carried out on the application of the technique in examining a tunnel lining physical model with a known position of the loose contact area. As examples of the application of the methodology, the results of the several monolitic structures of operating municipal and transport infrastructure underground structures survey are presented. The applicability of the technique for examining the grouting of the tunnel lining and the control of injection under the foundation slabs is confirmed. For data interpretation the modified three-sigma criteria and the joint analysis of the attribute’s behavior were successfully used. The features of the field work methodology, data collection and analysis are discussed in detail. Approaches to the techniques' development and its application in the framework of underground constructions monitoring are outlined. The issues arising during acoustic examination of reinforced concrete plate-like structures are outlined.
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Date submitted2024-03-07
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Date accepted2024-06-14
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Date published2024-07-04
Anomaly detection in wastewater treatment process for cyber resilience risks evaluation
Timely detection and prevention of violations in the technological process of wastewater treatment caused by threats of different nature is a highly relevant research problem. Modern systems are equipped with a large number of technological sensors. Data from these sensors can be used to detect anomalies in the technological process. Their timely detection, prediction and processing ensures the continuity and fault tolerance of the technological process. The aim of the research is to improve the accuracy of detection of such anomalies. We propose a methodology for the identification and subsequent assessment of cyber resilience risks of the wastewater treatment process, which includes the distinctive procedure of training dataset generation and the anomaly detection based on deep learning methods. The availability of training datasets is a necessary condition for the efficient application of the proposed technology. A distinctive feature of the anomaly detection approach is a new method of processing input sensor data, which allows the use of computationally efficient analytical models with high accuracy of anomaly detection, and outperforms the efficiency of previously published methods.
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Date submitted2021-10-27
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Date accepted2023-06-20
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Date published2023-12-25
Geomechanical analysis of the impact of the new tunnels construction in the vicinity of existing underground subway structures on the state of the soil massif
The specificity of the behavior of the soil massif near the tunnel under construction in difficult mining conditions is considered. It was revealed through the joint interpretation of the results of geophysical measurements in the tunnel and computer simulation. The results of field geophysical studies to identify areas of decompacted soil behind the lining in two existing tunnels during successive drilling of two new tunnels under them are described. A method to analyze the response of the lining to impact was used providing for the calculation of its energy. It has been established that the decompaction zones are mainly located in the lateral lower areas of the tunnel. To substantiate the mechanism of formation of cavities, computer simulations were carried out using the finite element method with the COMSOL Multiphysics software. The finite element model is built on the Drucker – Prager criterion in the variant of a two-dimensional problem statement. It is shown that at the initial position of two old tunnels, the areas of decompaction can develop mainly on the sides. The position of the zones changes significantly when excavating two new tunnels. Soil decompaction zones appear between the tunnels and there is a tendency for the areas to spread to the upper point of the tunnel. According to geophysical data time delays in the impact of new tunnels on the existing line are noted, as well as a decrease in the size of decompacted soil areas over time. There is a satisfactory agreement between the positions of the decompaction areas and voids obtained by the geophysical method and the results of numerical simulation.
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Date submitted2014-10-13
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Date accepted2014-12-22
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Date published2015-08-25
Optimum operating zones selection methods for multispectral overhead power lines remote sensing devices
- Authors:
- V. A. Shpenst
The article describes the main methodological aspects of designing multispectral optoelectronic devices intended for remote sensing of overhead power lines. Based on proposed indicators and detection criteria a method for selecting operating spectral zones for these devices is suggested, methods of researching into their efficiency and the results of simulating the process of their operation are described.
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Date submitted2009-09-05
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Date accepted2009-11-17
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Date published2010-06-25
Photoelectric method of hydrogen detection
The new photoelectric method of the detection of hydrogen is proposed, based on strong dependence of the photo induced current on concentration of hydrogen in III-V heterostructures with Pd contact. The given influence at a room temperature is stronger on few orders than influence of hydrogen on electric characteristics of solid-state elements in existing sensors. The original design of portable sensor module was developed on the base of photosensitive element and infrared light-emitting diode that meet demands of hydrogen power engineering.