Relative Depth Research Articles

Predicting the urban stormwater drainage system state using the Graph-WaveNet

Graph Neural Networks (GNNs) have been applied to network data such as traffic flow and water distribution systems, yet their use in predicting the state of urban stormwater drainage systems remains rare. This study investigates the application of Graph-WaveNet (GWN), a type of GNN, in forecasting the states of stormwater systems in Kowloon, Hong Kong. Data was sourced from the Storm Water Management Model (SWMM) spanning 43 rainfall events from 2020 to 2023. Based on the preceding 30 to 60 min of network states and rainfall data, GWN predicted junction inflows, pipe flow rates, and relative water depths (fraction of full area filled by flow) for lead times up to 20, 20, and 30 min, with an R2 greater than 0.6, respectively. Prediction accuracy declines with longer forecast horizons. GWN predicts more time steps ahead for pipes’ flow rates and junctions’ inflows, but fewer for relative water depths during peak versus non-peak periods. It is also more effective at predicting states of large pipes and connected junctions downstream, compared to smaller upstream components. GWN's accuracy improves significantly with precise rainfall nowcasting inputs. This study establishes a significant baseline for GWN's performance in predicting urban stormwater systems during rainfall events.

Numerical analysis of relative density effects on shallow TBM tunnel excavation: Ground behavior and principal strains at surface in greenfield conditions

Tunnel construction in urban areas may result in ground deformations that pose a risk to existing buildings and infrastructure; thus, accurate prediction of these induced ground deformations during the design phase is crucial. The paper focuses on the effects of sandy soil relative density on the ground deformations induced by tunnels excavated with Tunnel Boring Machines (TBMs). The study utilizes the Finite Element Method (FEM) and the NorSand model to simulate the behavior of a sandy ground. The validity of the FEM modeling approach is established by comparing predictions with results from six centrifuge tunnel tests from the literature. The centrifuge tests were performed on sand at different relative densities, tunnel diameters, and tunnel depths. The parameters for the NorSand model were determined based on laboratory tests. Only the state parameter was modified to achieve the desired relative density in the numerical simulations. The effects of relative density observed in centrifuge tests (Franza et al., 2019) have been numerically reproduced with no further adjustments of the model parameters. The rich outputs from the numerical models enabled an in-depth investigation of tunnel behavior, yielding new insights into how tunnels respond under varying relative densities, depths, and diameters. A comprehensive analysis of the induced ground deformations caused by shallow tunnels in sandy ground and the potential to damage buildings is included.

Influence of guide groove structure on in-flow drag reduction in spiral axial gas-liquid mixing pumps

Abstract With the onset of the fossil energy crisis, demand for oil has skyrocketed, and the spiral axial flow gas-liquid mixing pump has emerged as the primary piece of equipment for deep-sea oil extraction. However, at high gas content, the problems of separation of mixed media from hydraulic components, gas-liquid separation and gas phase aggregation are faced. The difficulties of gas-phase aggregation and bubble trajectory in the impeller channel have received much attention, while the problem of increased medium flow resistance induced by flow separation has received less attention. The spiral axial gas-liquid mixing pump is numerically calculated using the Eulerian multiphase flow model and the SST k- turbulence model in this work. The pump is designed with the design flow rate Q = 100 m3/h, rotational speed n = 4500 rmin, and head H = 30m by arranging guide slots with different relative depths and different number of slots to reduce the dissipative vortices, thus reducing the flow resistance in the 1/5 region behind the suction surface. The findings reveal that when the relative depth of the slots is 1/7 and the number of guide slots arranged is 5, the highest drag reduction rate in this location is 69.6% under the design flow condition. When the relative depth of the guide channel is1/7 and the number of guide channels is 3, the performance of the mixing pump is improved most, with an efficiency increment of 1.9% and a head increment of 4.2%, which can provide technical support for the flow resistance reduction of gas-liquid mixing pumps.

How do morphological characteristics affect tidal asymmetry in the Radial Sand Ridges?

While it is widely recognized that the Radial Sand Ridges (RSR) in the South Yellow Sea are predominantly shaped by tidal forces, there remains a limited understanding of how this distinctive morphological configuration—characterized by an interlaced channel-ridge system—can subsequently influence local tidal dynamics. This study examines the effects of morphological features on tidal asymmetry, taking into account seabed slope, relative depths between ridges and channels, and channel convergence. Three principal indices—namely tidal-duration-asymmetry (TDA), peak-current-asymmetry (PCA), and slack-water-asymmetry (SWA)—are employed to quantify various dimensions of tidal asymmetry. The findings indicate that SWA serves as the most morphology-sensitive indicator, whereas TDA exhibits minimal sensitivity to morphological changes. Furthermore, seabed steepness emerges as a critical factor influencing tidal asymmetry within the RSR; steeper slopes enhance intrinsic energy conversion processes, thereby inducing tidal asymmetries. Additional analysis reveals that streamwise advection accounts for an average of 88 % of total advection scale while controlling for spatial heterogeneity. Specifically, the average integral sum of advection terms along submerged sand ridges is 2.53 times greater than that along the deepest section of the tidal channel line—a significant contributor to spatial variability in SWA. With a positive seabed slope, the apex of the RSR acts as a source for overtides which interact with incoming astronomical tides, consequently generating tidal asymmetries. Moreover, this study illustrates varying dependencies of tidal asymmetry on bottom stress across channels and ridges, contributing to spatial variability in arc direction among RSRs. Ultimately, this research elucidates complex interactions between tidal flow and morphological characteristics within RSRs and provides insights into tide evolution in analogous ebb-shoal systems.

Dolomite, quartzite, and sand indices defined for PRISMA hyperspectral data. Application to the Tamlalet inlier (Eastern High Atlas, Morocco)

The present work discusses the development of three novel spectral indices for PRISMA data. The Hyperspectral Dolomite Index (HDI) using B2320nm and B2349nm bands, the Hyperspectral Sand Index (HSI) based on the visible B515nm and B596nm bands, and the Hyperspectral Quartzite Index (HQI) using a combination of Relative Band Depths in B2167nm and B2206nm bands. The outputs of the three indices are grayscale images, where the brightest pixels represent the indices target. Applying HDI on PRISMA image of Tamlalet inlier (Moroccan Eastern High Atlas) led to discriminate the dolomites from lacustrine limestones and bare soils. HDI also suggests rectifying the local geological map by replacing limestones with dolomites in Jbel Ain Chair. HQI highlights quartz-rich rocks and provides better results than ASTER TIR indices. HSI can discriminate sand dunes from bare soils without being disturbed by vegetation. Dolomite, Quartzite, and Sand Hyperspectral indices show an overall accuracy of 91.2 %, 97.8 %, and 91.5 %, respectively. These indices could be adapted to other hyperspectral data having the required wavelengths.

Physical modelling study on wave damping induced by an idealized floating kelp farm

A physical modelling study was carried out to investigate random wave damping promoted by an idealized floating kelp farm. The experimental conditions spanned intermediate water depths and both linear and nonlinear water waves. Unlike previous studies of wave damping promoted by vegetation, the floating kelp farm was placed close to the water surface with a ratio between vegetation height and water depth close to 0.25. The wave transmission coefficient induced by the floating kelp farm ranged between 0.56 and 0.96. This coefficient decreased for longer floating kelp farms and it was a function of the ratio between kelp farm length and incident wavelength and of the relative wave depth. Spectral analysis showed that wave damping was not frequency-dependent for wave frequencies close to the peak frequency. The wave transmission coefficients of a floating kelp farm with about 100 culture lines and with an extension of approximately 200 m were similar to those of submerged detached breakwaters with a relative crest freeboard smaller than -0.4. Furthermore, the bulk drag coefficient of near-surface idealized floating kelp farms can be modelled as a function of the Keulegan-Carpenter number. This study highlights the potential viability of nature-based solutions such as floating kelp farms for coastal protection.

Exploiting the potential of images from the aster and landsat 9 satellites for the mapping of hydrothermal alteration minerals associated with mineralization in the departments of Abtouyour and Guera, located in the Chadian massif central (republic of Cha

This article deals with the use of remote sensing with Aster and Landsat 9 imagery for mapping hydrothermal alteration minerals and oxides in relation to mineralization. Aster VNIR (Visible and Near Infrared) and SWIR (Mean Infrared) data are used to calculate PCA (Principal Component Analysis), RBD (Relative Band Depth) and BR (Band Ratio). These different parameters are used to highlight the groups of hydrothermal alteration minerals and oxides. Landsat data are used for mapping lithological units using PCA and BR. The identified mining areas coincide with the gold planning sites of Toumka and Lellé and allow to know the interesting areas for future mining prospecting campaigns in the departments of Abtouyour and Guéra (Guéra province).

Environmental Lighting Conditions, Phenomenal Contrast, and the Conscious Perception of Near and Far.

Recent evidence in systems neuroscience suggests that lighting conditions affect the whole chain of brain processing, from retina to high-level cortical networks, for perceptual and cognitive function. Here, visual adaptation levels to three different environmental lighting conditions, (1) darkness, (2) daylight, and (3) prolonged exposure to very bright light akin to sunlight, were simulated in lab to investigate the effects of light adaptation levels on classic cases of subjective contrast, assimilation, and contrast-induced relative depth in achromatic, i.e., ON-OFF pathway mediated visual configurations. After adaptation/exposure to a given lighting condition, configurations were shown in grouped and ungrouped conditions in random order to healthy young humans in computer-controlled two-alternative forced-choice procedures that consisted of deciding, as quickly as possible, which of two background patterns in a given configuration of achromatic contrast appeared lighter, or which of two foreground patterns appeared to stand out in front, as if it were nearer to the observer. We found a statistically significant effect of the adaptation levels on the consciously perceived subjective contrast (F(2,23) = 20.73; p < 0.001) and the relative depth (F(2,23) = 12.67; p < 0.001), a statistically significant interaction between the adaptation levels and the grouping factor (F(2,23) = 4.73; p < 0.05) on subjective contrast, and a statistically significant effect of the grouping factor on the relative depth (F(2,23) = 13.71; p < 0.01). Visual adaption to different lighting conditions significantly alters the conscious perception of contrast and assimilation, classically linked to non-linear functional synergies between ON and OFF processing channels in the visual brain, and modulates the repeatedly demonstrated effectiveness of luminance contrast as a depth cue; the physically brighter pattern regions in the configurations are no longer consistently perceived as nearer to a conscious observer under daylight and extreme bright light adapted (rod-saturated) conditions.

Canopy coverage of wheat measured with high accuracy using the HSV colour model and relative depth estimation model, MiDaS

ABSTRACT Canopy coverage calculated from 2D images effectively estimates several parameters, such as dry weight above the ground, stem number, and risk of lodging, without destroying the crops. This study aimed to clarify how to accurately calculate canopy coverage, regardless of environmental conditions, using various colour models and a relative depth estimation model, MiDaS. For wheat cultivated in 2022/23, the canopy coverage at the initiation of the stem elongation stage (CC30), calculated using only the HSV colour model, was overestimated because of the presence of weeds. However, when the heatmap generated using MiDaS was combined with the results extracted from the HSV colour model, it showed a CC30 similar to the accurate CC30 calculated by hand drawing, regardless of the wheat variety, sowing pattern, and location of the image taken, with an RMSE as low as 3.48. The CC30 calculated by combining the HSV colour model and MiDaS was significantly positively correlated with the number of stems, dry weight above ground, and nitrogen content above ground at the initiation of the stem elongation stage of ‘Sanukinoyume 2009’ grown in 2021/22 and 2022/23 (n = 72, r > 0.798). The combination of the HSV colour model and MiDaS effectively and accurately calculates canopy coverage regardless of environmental conditions and can be used for growth diagnosis and variable nitrogen fertiliser application after the initiation of the stem elongation stage.

Experimental investigation of equilibrium and temporal scour around the round head of the rubble mound breakwater in case of breaking and non-breaking waves

In this study, local sediment movements caused by regular wave effects around the head section of rubble mound breakwater were investigated experimentally. The experiments were performed in a wave channel with a length of 33 m, a width of 3.6 m and a depth of 1.2 m. A plunger-type wave generator was located at the offshore side, generating regular waves of varying heights and periods. Uniform sandbed material of three different grain sizes was used, alongside two distinct breakwater slopes and six different wave characteristics. Experiments were performed under both breaking and non-breaking wave conditions. Time-dependent scour depth and water level measurements were determined by using measuring equipment working with an ultrasonic method. In the paper, new empirical relations were derived for temporal relative scour depths and the non-dimensional time scale parameter and the non-dimensional time scale parameter. The determination coefficient and scatter index of these derived relations were calculated and evaluated statistically. It was observed that the relations are in good agreement with those obtained from experiments. Additionally, the findings indicate that wave breaking significantly reduces the equilibrium scour depth.

Shallow Focal Depths of the 2022 Ms 6.8 Luding Earthquake and Its M ≥3 Aftershocks

Abstract The accurate determination of earthquake focal depths is crucial, yet notably challenging. The 2022 Ms 6.8 Luding earthquake sequence is a typical example for which focal depths remain controversial. In this study, we conducted a comprehensive regional waveform analysis, including depth-phase waveform modeling and relative location methods, to determine the focal depths of the Ms 6.8 mainshock and its M ≥ 3 aftershocks. Specifically, we first inverted the focal mechanisms of these events using the generalized cut-and-paste method. We then determined their absolute focal depths using array-based stacking and Pn depth-phase modeling. For events without clear depth phases, we calculated their relative depths with respect to the known ones using differential travel times of Pg, Sg, and Pn phases. Our results indicate that the mainshock’s hypocenter lies at a depth of 11 km, whereas its centroid appears at a shallower depth of ∼6.5 km. All M ≥ 3 aftershocks are located within a narrow depth range of 3–7 km, in contrast to the deeper focal depths previously obtained using conventional travel-time-based location methods. This shallow seismogenic depth aligns well with the rheological behavior of the crust along the southern Xianshuihe fault, in which the brittle–ductile transition depth is estimated to be about 10km. Our results reveal that the mainshock nucleated at the base of the seismogenic zone and ruptured toward the shallower portion, consistent with the geodetically constrained mainshock slip distribution. Our study also emphasizes the necessity of caution when interpreting focal depths determined by routine travel-time-based methods, especially in regions with sparse seismic station coverage.

Relative depth discrimination in natural images of paired human body joints

Relative depth discrimination in natural images of paired human body joints

Development and evaluation of hydraulic geometry relationships for large Brazilian river basins

ABSTRACT River cross-section characteristics are not available for many regions of the world, and they are generally expressed as hydraulic geometry (HG) relationships. These relationships usually represent average characteristics of a region, which can generate biased estimates in smaller basins. Therefore, to improve the representation of river channel geomorphological characteristics, the objective of this study was to use a large database of river cross-section geometries to refine HG relationships for five river basins in Brazil. HG relationships were developed for the entire basins and for hydraulically homogeneous regions, obtained through a geographical convenience method. The relationship between the coefficients of the geometric relationships and morphoclimatic characteristics was assessed, showing a trend between precipitation and slope and the coefficients of the depth relationships. The estimated bankfull width and depth values were also compared to observed data and global datasets, showing an improvement in estimates with the more refined HG relationships.

Hydrodynamic Performance of an Inverted Trapezoidal Breakwater with Permeable Retrofit

Abstract The scattering of incident waves by a surface-piercing inverted trapezoidal breakwater (SPTB) encircled by retrofit is numerically examined based on the assumptions of potential flow theory. The dual boundary element method is adopted to evaluate the hydrodynamic performance of the retrofitted SPTB breakwater. The scattering coefficients (i.e., wave transmission, wave reflection, energy loss), and force coefficients acting on the inner SPTB and outer retrofit are reported against relative water depth for various input values of breakwater and incident waves. The SPTB with 10% porosity, spacing S/h=0.25, width varied within 1.5≤B/W≤2, and depth d/h=0.2 is suggested against the incident waves to secure the coastal infrastructure.

Effect of dual modification on structural, functional and dielectric properties of cassava starch

The combined effect of hydrocolloid addition and microwave heating on the structural, physical and functional properties of cassava starch remains underexplored, despite individual studies on these modification methods. The dielectric properties, important for the microwave treatment of starch, have received little attention in recent studies. Cassava starch with and without addition of hydrocolloids (guar and xanthan gums) was modified by microwave heating for two different exposure times, and its structural, functional, and dielectric properties were studied. The dual modification enhanced the swelling power and oil holding capacity of the starch, reduced its gelatinization temperature, and did not alter its crystallinity. Notably, xanthan-modified starch microwaved for 6 min exhibited higher color variation (ΔE*) and increased granules agglomeration, while the microwave treatment alone roughened the surface of the starch granules. The mean diameters D[4,3] of starch increased with xanthan gum addition, microwave treatment (6 min), and their combination. The relative permittivity (ε’), loss factor (ε”) and penetration depth (Dp) were lower for samples modified by the combined method. Considering the type of hydrocolloid and the microwave exposure time, the combined modification significantly influenced the properties of starch, offering a promising approach to producing starch with enhanced functional properties.

Monocular vision-based structural out-of-plane motion estimation using a deep learning method

Computer vision-based displacement estimation methods can estimate structural motion from videos, but face challenges in estimating out-of-plane motion. Conventional vision-based methods employ either multi-view camera systems or structural model-aided monocular vision methods to estimate structural out-of-plane motion. Nonetheless, the utilization of multi-view camera systems leads to additional costs and stringent requirements for overlapping views, while structural model-aided methods require comprehensive structural information. To achieve convenient and accurate out-of-plane structural displacement measurement, this study presented a monocular vision-based measurement method using a deep learning technique. Firstly, a deep learning model was employed to estimate the global depth matrix of images. The relative depth of the region of interest (ROI) was then estimated through pyramid-accelerated tracking and relative depth matrix weighting. To convert the relative depth into actual out-of-plane motion, the scale factor was calculated through least squares fit. The performance of the proposed method was validated through static and dynamic tests. The results indicated that the proposed approach yielded reasonable out-of-plane motion estimations, with correlation coefficients with displacement sensor measurements over 0.93. The proposed method therefore offered a cost-effective and convenient alternative for structural out-of-plane motion estimation.

Is postoperative high dependency care really needed for children undergoing supratentorial brain tumour surgery?

Purpose We present our analysis of the existing Paediatric High Dependency Unit (HDU) admission policy at our institution and discuss our thoughts for its revision in the context of paediatric supratentorial tumour surgery. Materials and methods We screened our prospectively maintained database of all children undergoing supratentorial craniotomy for resection of paediatric brain tumours over a fifteen-year period. The post-operative course of each patient was reviewed, assessing the number of patients who had true HDU needs in the immediate post-operative period, and the relative depth of input from paediatric HDU specialists that each patient received. Results Forty-three patients underwent craniotomy for supratentorial tumour resections during the study period. The median age of the children was 8 years old. Forty-two patients in the study cohort did not require any HDU-level monitoring or treatment post-operatively; all these patients were able to be discharged from HDU to a standard ward bed very rapidly post-operatively. Only one patient (2%) from the study cohort had any tangible HDU needs in the acute post-operative period, comprising of invasive cardiovascular monitoring and repeated blood transfusions. This child’s tumour was known to be large, highly vascular, and invasive pre-operatively. Conclusions We would advocate a rational and nuanced approach with regards to predicting which children are most likely need paediatric HDU care following supratentorial craniotomy for resection of a brain tumour. This rationalisation could improve resource availability and reduce financial burdens upon paediatric neurosurgical units.

Evaluating endotracheal tube length in very and extremely preterm infants

Objective Our study objective was to evaluate changes in ETT tube depth throughout the initial intubation course in very and extremely preterm infants in order to evaluate the risk of outgrowing an endotracheal tube (ETT). Methods This was a retrospective cohort study of preterm infants born at <32 weeks of gestation who were admitted to the NICU between 2012 and 2021 and required intubation for mechanical ventilation. Infants who were intubated only for surfactant administration and those with airway malformations were excluded. Descriptive statistics were used to define the range of ETT depths at the time of extubation, stratified by gestational age (<28 weeks vs 28–32 weeks of gestation). Relative ETT depth was defined as the final depth minus the initial depth. Results Out of 496 infants, 140 patients met all criteria for inclusion. Descriptive analysis of extubation depths across the populations demonstrated median relative ETT depth of 0 cm for the 28–32-week gestational age group, and −0.25 cm for the <28-week gestational age group. The 95th percentile for both gestational age groups was a relative depth of 0.5 cm and the 99th percentile was 1.0–1.5 cm. Conclusion The results of our study suggest that the vast majority of patients in the NICU are unlikely to “outgrow” ETT tube length which should be taken into account when deciding where to trim the ETT in order to minimize airway resistance.

Evaluating Interior Space Perception using Virtual Reality

This study evaluates the effectiveness of Virtual Reality (VR) in enhancing spatial perception compared to traditional 2D representations in the context of interior design education. Conducted with Interior Architecture students at the University of Buraimi, the research utilized the Oculus Quest 2 VR headset to create an immersive environment. Participants assessed various spatial characteristics, such as depth, scale, and spatial relationships, using both printed materials and VR immersion. Findings indicate that VR significantly improves the accuracy and realism of spatial perception, providing a more comprehensive understanding of interior spaces. This research contributes to the growing body of knowledge on VR applications in architectural education, highlighting its potential benefits and challenges.

Turbulence and sediment deposition in a channel with floating vegetation

Floating canopies of vegetation alter the vertical profile of flow velocity within and below canopies, which in turn impacts sediment deposition below canopies. This study explored the impacts of channel-average velocity (U0), vegetation density (a), and relative flow depth (hg/H, where hg is the height of the free flow region below the floating canopy and H is the entire flow depth) on the longitudinal distributions of near-bed turbulent kinetic energy (TKE) and sediment deposition in a channel with a floating vegetation canopy. Below a floating canopy, sediment deposition was correlated with the near-bed TKE. For the low-density and low-velocity cases, sediment deposition was spatially uniform across the entire channel because the near-bed TKE was lower than the critical value for sediment resuspension. As the vegetation density and channel-average velocity increased, the near-bed TKE increased and surpassed the critical TKE, which caused resuspension and reduced deposition below the canopy relative to the upstream reference. For the same vegetation density and channel-average velocity, a lower relative flow depth (hg/H) produced a higher below-canopy depth-averaged velocity and near-bed TKE, resulting in less deposition below the canopy. A model was proposed for predicting the longitudinal evolution of near-bed TKE based on the predicted flow velocity below the canopy throughout the channel. The longitudinal evolution of deposition below a floating canopy was predicted by combining the predicted near-bed TKE with the deposition probability. The predicted near-bed TKE and deposition matched laboratory measurements. Finally, the proposed model can be used to predict the longitudinal profile of deposition below a real Eichhornia crassipes canopy.