Advance prediction method for rock mass stability of tunnel boring based on deep neural network of time series

Geological layers excavated using tunnel boring machines are buried deeply and sampled difficultly, and the geological behavior exhibits high diversity and complexity. Excavating in uncertain geology conditions bears the risks of excessive damage to the equipment and facing geologic hazards. Many scholars have used various signals to predict the advance geology conditions, but accurate prediction of these conditions in real-time and without effecting operations has not been realized yet. In this article, based on a large amount of corresponding data, an advance prediction model of the rock mass category (RMC) is formulated. First, the problem is divided into two parts, which are modeled separately to reduce the complexity of design and training. Then, the two models are combined in a pre-trained model, which is retrained to as the final prediction model to avoid the problem of error accumulation. The final model can predict the advance RMC in real-time and without affecting operations. The accuracy of the prediction model reaches 99% at an advance time of 60 min. The advance RMC can be used to guide the selection of support modes and control parameters without additional detection equipment and excavation down-time.

Determination of the required amount of traffic of suburban trains, taking into account all-day and intraday irregularities in passenger traffic distribution

Objective: Automation of processing data on passenger traffi c in an arbitrary direction in order to determine the number of “threadsˮ in the time schedule for suburban passenger traffi c in the future. Verifi cation of the adequacy of the existing infrastructure and design solutions for reconstruction in terms of ensuring the required throughput capacity of railway lines. Methods: The calculation of the number of trains is carried out by mathematical modeling of passenger traffi c distribution by hours of the day on each day of the week of the initial month. The identifi cation of trains with non-daily destination is made by comparing the calculation results for each day of the week. Results: An algorithm has been developed for calculating on a computer the perspective amount of suburban train traffi c, taking into account the uneven distribution of passenger traffi c by hours of the day and days of the week. Practical importance: The data obtained using the presented algorithm makes it possible to simplify the development of advance time schedules, taking into account the needs of the population in transportation. The results of the work can be used in feasibility studies for the reconstruction of station layout development and passenger devices, as well as serve as the basis for the technical re-equipment of lines in order to increase their throughput (replacement of signaling and communication equipment, construction of second main tracks, reconstruction of yard necks, etc.). The results of the calculation also make it possible to identify schedule “threadsˮ for withdrawal of trains on days of the week when they are not in demand, but at the same time take into account non-daily trains when developing a standard time schedule. The form of presentation of the results takes into account the spatial irregularity of passenger traffi c and makes it possible to distinguish zonal trains.

A neural network-based mid-term prognosis of geomagnetic storms that uses pre-storm effects related to current sheets and magnetic islands

<p>Mid-term prognoses of geomagnetic storms require an improvement since theу are known to have rather low accuracy which does not exceed 40% in solar minimum. We claim that the problem lies in the approach. Current mid-term forecasts are typically built using the same paradigm as short-term ones and suggest an analysis of the solar wind conditions typical for geomagnetic storms. According to this approach, there is a 20-60 minute delay between the arrival of a geoeffective flow/stream to L1 and the arrival of the signal from the spacecraft to Earth, which gives a necessary advance time for a short-term prognosis. For the mid-term forecast with an advance time from 3 hours to 3 days, this is not enough. Therefore, we have suggested finding precursors of geomagnetic storms observed in the solar wind. Such precursors are variations in the solar wind density and the interplanetary magnetic field in the ULF range associated with crossings of magnetic cavities in front of the arriving geoeffective high-speed streams and flows (Khabarova et al., 2015, 2016, 2018; Adhikari et al., 2019). Despite some preliminary studies have shown that this might be a perspective way to create a mid-term prognosis (Khabarova 2007; Khabarova & Yermolaev, 2007), the problem of automatization of the prognosis remained unsolved.</p>

Validation of Surge Model Using Furrow Gradient and Flow Retardance

Introduction: Surface irrigation, our oldest method of applying water on to the cropped land, has withstood the test of time because of its many advantages. Over the years, minor changes have been made to improve the efficiency of surface irrigation system. Aim: The present study was taken to validate the existing model with furrow gradient and flow retardance. Principle: The experimental layout has been made to accommodate the variance such as the furrow gradients (0.3%, 0.6% and 0.1%), the modes of irrigation namely the continuous flow as control and the surge flow as the treatment. Surge irrigation is a relatively new technique whereby water to surface irrigated furrows is applied intermittently in a series of relatively short ON and OFF time periods of irrigation cycles. Results: It is claimed that the ON-OFF cycling of the flow for specific time periods produces surges during the ON period and influences the soil intake during the OFF period when water soaks into the soil. The net result is a reduction in soil infiltration rates during subsequent surge ON periods and an increase in the rate of water front advance. The SURGEMODE model can only gives the net water front advance time that can be predicted for non-vegetated condition and a standard reference slope. However when the furrow is getting vegetated or when the slope gradients are changed, the water front advance predicted through the existing model cannot be predict accurately. Conclusion: Hence, the study involved to validate the existing model with furrow gradient and flow retardance. The use of revalidated existing SURGEMODE model with the correction factor would be the exact suitable model for the local condition.

Infiltration and Soil Water Distribution in Irrigation Furrows Treated with Polyacrylamide

HighlightsControl furrows with 1× inflow rates were compared with 3× advance inflows treated with 10 mg L-1 polymer (WSPAM).WSPAM reduced sediment loads in furrow streams by 89%, despite its 3× greater advance inflows.WSPAM furrow advance times and infiltrated volumes were greater than predicted from increased inflows alone.WSPAM enabled reduced upper-section infiltration and increased lower-section infiltration relative to control furrows.Abstract. Few if any studies have measured the effects of water-soluble anionic polyacrylamide (WSPAM) on infiltration and soil water distribution in different segments of irrigation furrows. We conducted a four-year study on a silt loam soil with 1.5% slopes. Control furrows received no WSPAM and inflows were 15.1 L min-1, whereas WSPAM was applied using 10 mg L-1 a.i. to 45 L min-1 inflows during furrow advance. Despite its greater advance phase inflow rates, WSPAM application reduced sediment concentrations in furrow streams by an average of 89% relative to the control. A surface irrigation model, WinSRFR 5.1, was used to separate furrow inflow rate effects on infiltration from that of WSPAM. Relative to results predicted by simulation for the entire furrow, the polymer treatment: (1) increased advance time an average 1.4-fold, (2) increased advance-phase infiltrated volume 1.5-fold, and (3) increased infiltration volume at the common opportunity time 1.2-fold. Hence, these effects resulted from WSPAM and not from differences in treatment inflow rates. Treatment infiltration amounts varied markedly among irrigations and years, as did the intensity of WSPAM effects. These were attributed mainly to differences in infiltration opportunity time, but temporal differences in soil water content during furrow formation, irrigation water electrical conductivity, initial soil surface water content and water temperature, and the irrigation-long, furrow-stream mean sediment content also appear to have influenced infiltration rates. Although inconsistent, WSPAM increased net furrow infiltration in the lower section and reduced infiltration in the upper section relative to control furrows. This effect could not be explained by the greater inflow rate and shorter advance time of the WSPAM treatments and was attributed to spatially variable WSPAM effects on infiltration opportunity time and possibly irrigation water viscosity. The WSPAM management approach, while protecting against furrow erosion, may potentially provide a means of improving irrigation uniformity and reducing associated percolation water and nutrient losses. Keywords: Furrow advance, Irrigation, Irrigation uniformity, Polymers.

Assessment of straight and meandering furrow irrigation strategies under different inflow rates

This paper reports the effect of straight furrow (SF) and meandering furrow (MF) irrigation strategies, as well as inflow rate, on infiltration and hydraulic parameters including advance time, recession time, and runoff hydrograph. The performance of SF and MF irrigation in terms of runoff ratio, deep percolation, and application efficiency was evaluated in 6 furrow fields at Shahid Bahonar University of Kerman, Iran. The required data were collected from the farm, consisting of free drainage furrows with length 70 m, top width 0.8 m, depth 0.25 m, and slope 0.2%. The advance and recession times were significantly longer in MF than SF irrigation. The infiltration was estimated by Lewis-Kostiakov equation. The infiltration coefficients were calculated: The values of k were higher and of a were lower in MF furrows than in SF furrows. The average runoff ratio and application efficiency for the SF irrigation events were 50.53% and 49.07%, respectively, while those of the MF irrigation events were 7.04% and 52.94%, respectively. Based on the results, the velocity of water advance in MF irrigation is decreased and, thus, the runoff, erosion losses, mass of fertilizer lost and surface water contamination were reduced. Using a lower inflow rate and appropriate irrigation time leads to better management outcomes in irrigation systems.

Ultrasonic Guided Wave Phased Array Focusing Technology and Its Application to Defrosting Performance Improvement of Air-Source Heat Pumps

Previous studies have indicated that a basic frost layer negatively affects the heat-transfer efficiency and is difficult to remove using a single ultrasonic transducer. Herein, an ultrasonic phased array technology is proposed for evaporator coil defrosting. First, the dispersion curve of the guided wave in the vibration transfer plate and frosting fin is calculated, and the advance time of each ultrasonic vibrator and the ultrasonic near-field pressures under different velocities are determined through numerical calculations using the MATLAB software. Next, according to the advance time, ultrasonic array focusing is performed to remove the basic frost layer. Finally, the power consumption, heat-supply enthalpy difference, and coefficient of performance (COP) of the air-source heat pump (ASHP) unit are analysed. The theoretical analysis, numerical calculations, and experimental results consistently revealed that ultrasonic array focusing compensates for the energy dissipation and expends the effective defrosting area. Additionally, the perpendicular stress elicited by the Lamb wave and the differential transverse shear stress generated by the SH wave exceed the tensile strength and adhesion stress of the basic frost layer. The basic frost layer cracks and falls away, owing to the combination of the ultrasonic stress effect and the cavitation effect. The defrosting power consumption of the ASHP unit under ultrasonic array excitation decreases from −3.27% to 0.12%, whereas the heat-supply enthalpy difference increases from 4.47% to 10.86%. Therefore, the percentage increment of the COP is between 7.16% and 11.12%, and the power consumption of the reverse-cycle defrosting is 3–12 times that of ultrasonic array defrosting.

A Review on Using Opportunities of Augmented Reality and Virtual Reality in Construction Project Management

Augmented reality (AR) and virtual reality (VR), a kingdom-of-the-art technology for superimpos­ing information onto the real world, have recently started to have an effect on our everyday lives. In addition, AR and VR have shown a great contribution to advanced construction management in recent years. However, a comprehensive critical review of AR and VR technolo­gies in construction management is absent in the liter­ature. This study provides a comprehensive review of a summary of using potential opportunities of AR and VR to solve a variety of construction management issues effectively and efficiently. This study found that AR is successfully used in construction project scheduling, progress tracking, worker training, safety management, time and cost management, and quality and defects management. VR is effectively used as a visualization tool, worker training technology, safety management tool, and quality and defects management tool. In addi­tion, AR and VR are used for developing a network that allows the possibility of having conferences with those who are geographically far off from each other or the construction site. This study could help to explore the potential fields of using AR and VR technologies in the construction industry effectively as advance time- and cost-saving profitable tools.