Horizontal Location Research Articles

Functional Connectivity Encodes Sound Locations by Lateralization Angles.

The ability to localize sound sources rapidly allows human beings to efficiently understand the surrounding environment. Previous studies have suggested that there is an auditory "where" pathway in the cortex for processing sound locations. The neural activation in regions along this pathway encodes sound locations by opponent hemifield coding, in which each unilateral region is activated by sounds coming from the contralateral hemifield. However, it is still unclear how these regions interact with each other to form a unified representation of the auditory space. In the present study, we investigated whether functional connectivity in the auditory "where" pathway encoded sound locations during passive listening. Participants underwent functional magnetic resonance imaging while passively listening to sounds from five distinct horizontal locations (-90°, -45°, 0°, 45°, 90°). We were able to decode sound locations from the functional connectivity patterns of the "where" pathway. Furthermore, we found that such neural representation of sound locations was primarily based on the coding of sound lateralization angles to the frontal midline. In addition, whole-brain analysis indicated that functional connectivity between occipital regions and the primary auditory cortex also encoded sound locations by lateralization angles. Overall, our results reveal a lateralization-angle-based representation of sound locations encoded by functional connectivity patterns, which could add on the activation-based opponent hemifield coding to provide a more precise representation of the auditory space.

Adjoint‐based observation impact on meteorological forecast errors in the Arctic

AbstractAccurate weather forecasting using numerical weather prediction in the Arctic remains a challenge owing to the complex atmospheric dynamics and relatively sparse observations of the region. Nevertheless, the impact of observations used for data assimilation (DA) on forecast errors (observation impacts, OIs) in the Arctic has not been fully explored. This study evaluated the OIs on 24 hr forecast errors in the Arctic by the adjoint‐based forecast sensitivity OI (FSOI) method using the Polar Weather Research and Forecasting (WRF) model, three‐dimensional variational DA, and adjoint model of WRFPLUS. The time‐averaged FSOI during August 2018 was analyzed in terms of the type, variable, satellite channel, altitude, and horizontal location of the observations. The results showed that the total FSOI was greatest for aircraft observations (AIRCRAFT), followed by sonde observations, scatterometer sea‐surface winds, advanced microwave sounding unit‐A radiance data from each satellite, and surface synoptic observations. The impact of AIRCRAFT in reducing forecast errors was greater in the Arctic than in other regions of the globe. The total FSOI of the advanced microwave sounding unit‐A radiance data from all four satellites was the greatest among the total FSOI of the individual observation types. For both AIRCRAFT and sonde observations, the FSOI per observation increased at higher latitudes, indicating that forecast errors in the Arctic could be reduced when upper atmospheric in‐situ observations at higher latitudes are used for DA. The beneficial ratio of the Global Positioning System precipitable water in the Arctic was greater than that in the midlatitudes with relatively moist atmospheres that cause greater uncertainties in converting zenith wet delay. The results of this study can contribute to configuring an optimal observing system in the Arctic by presenting the relative importance of observations for reducing forecast errors.

Modeling and Hybrid Inversion of Mineral Deposits Using the Dipping Dike Model with Finite Depth Extent

The dipping dike model has shown to be a useful approximation for mineral deposits. To make this model more realistic, we include the thickness, which yields the depth to the bottom, as an additional parameter. The magnetic anomaly is obtained by combining the anomalies of two infinite dikes, so that the resulting expression is simpler than the classical prismatic models with polygonal cross section. We employ a Metropolis-Hasting (MH) algorithm coupled with the Levenberg-Marquardt (LM) method to invert magnetic profiles assuming a model of multiple dike-like sources. We use a few iterations of the LM method to improve the candidate solutions at the end of each random walk generated by MH. The following parameters are obtained: depth to the top, thickness, half-width, horizontal location of the top center, geological dip, in addition to two effective parameters that depend on the intensity of magnetization and the directions of the induced and remanent fields. For synthetic anomalies, both noise-free and noisy magnetic data are considered, with examples presented for each scenario. These examples highlight the discrepancy between models with finite and infinite sources. They also illustrate the higher accuracy of the hybrid MH-LM method over the pure MH approach. Moreover, two field examples related to mineral exploration have been considered: the Pima copper mine, United States, where the relative differences between the parameters obtained by our algorithm and those known from drilling are not higher than 10%, and a magnetic profile over iron ore deposits located in Laje, northeast Brazil, where the inverted parameters were useful for detailing previous studies.

Shadow Mask Molecular Beam Epitaxy for In‐Plane Gradient Permittivity Materials

AbstractInfrared spectroscopy currently requires the use of bulky, expensive, and/or fragile spectrometers. For gas sensing, environmental monitoring, or other applications, an inexpensive, compact, robust on‐chip spectrometer is needed. One way to achieve this is through gradient permittivity materials, in which the material permittivity changes as a function of position in the plane. Here, synthesis of infrared gradient permittivity materials is demonstrated using shadow mask molecular beam epitaxy. The permittivity of the material changes as a function of position in the lateral direction, confining varying wavelengths of infrared light at varying horizontal locations. An electric field enhancement corresponding to wavenumbers ranging from ≈650 to 900 cm−1 over an in‐plane width of ≈13 µm on the flat mesa of the sample is shown. An electric field enhancement corresponding to wavenumbers ranging from ≈900 to 1250 cm−1 over an in‐plane width of ≈13 µm on the slope of the sample is also shown. These two different regions of electric field enhancement develop on two opposite sides of the material. This demonstration of a scalable method of creating in‐plane gradient permittivity material can be leveraged for the creation of a variety of miniature infrared devices, such as an ultracompact spectrometer.

An Acoustic Sensor System to Measure Aeolian Ripple Morphology and Migration Rates.

Acoustic distance sensors have a long history of use to detect subaqueous bedforms. There have been few comparable applications for aeolian bedforms such as ripples. To address this, we developed a simple and reliable apparatus comprising a pair of distance sensors, a bracket upon which they are mounted, and a base upon which the bracket can slide. Our system relies on two Senix Corporation (Hinesburg, VT, USA), ToughSonic® model 14-TSPC-30S1-232 acoustic distance sensors: one to measure surface elevation changes (in this case, ripple morphology) and a second to measure horizontal location. The ToughSonic® vertical resolution was 0.22 mm and the horizontal scan distance was about 0.60 m with a locational accuracy of 0.22 mm. The measurement rate was 20 Hz, but we over-sampled at 1 KHz. Signal processing involves converting volts to meters, detrending the data, and removing noise. Analysis produces ripple morphologies and migration rates that conform with independent measurements. The advantages of this system relative to terrestrial laser scanning or structure from motion are described.

Intelligent detection of underground openings and surrounding disturbed zones

This study aims to develop an intelligent method to detect subsurface anomalies for prediction and mitigation of geologic risks. We trained a convolutional neural network (CNN) model using the seismic data from 6 field cases of regular pipes and irregular cavities and a sliding time window technique to augment the datasets, and tested the CNN model using another 2 field cases. We derived probability distribution as an indicator of anomaly existence and validated high-value and low-value probability distributions corresponding to underground openings and surrounding disturbed zones, respectively. We found that the characteristics of subsurface anomalies determines the effective seismic features and influences the CNN model performance. Finally, we applied the CNN model to investigate a circular-bored tunnel and surrounding disturbed zones. Our results demonstrate that the CNN model is fast and accurate to detect the horizontal locations of subsurface anomalies, while the accuracy of vertical locations depends on the estimation of P-wave velocity. The intelligent method has the potential to identify hidden risks at early stages and to mitigate subsequent geologic hazards.

Thermal management and power generation characteristics in a bifurcating channel by using a piezo-embedded inclined elastic fin assembly during turbulent forced convection of ternary nanofluid

Numerous engineering systems use piezoelectric energy harvesters (PE-EHs), which have several benefits including low cost, simplicity, better power density, and ease of installation. They can be used in different applications for energy harvesting and different external sources such as wind and vortex induced vibrations due to fluid–structure interaction can be utilized. This study uses a unique elastic fin PE/EH assembly for power generation, thermal management, and flow control in a bifurcating channel. Performance of the system is improved by using ternary nanofluid in the channel cooling system. Galerkin weighted residual FEM with ALE is used as the solution method. The convective heat transfer performance and power generation by the EH device are investigated in relation to the varying following parameters: Reynolds number (Re between 10000 and 30000), PE-EH inclination (γ between 0 and 60), fin horizontal location (xf between −H and H), and nanoparticle loading in the base fluid (ϕ between 0 and 0.03). The vortex size and distribution near the junction are significantly influenced by the fin inclination and horizontal location of the fin assembly within the bifurcating channel. When varying other parameters of interest, using nanofluid at the highest loading results in significant deflection of the fin assembly and power generation within the PE-EH. Enhancement factors (EFs) for power generation becomes 15.6 and 39.8 when cases of lowest and highest Re are compared with pure fluid and nanofluid while they are 2.93 and 3.38 for thermal performance improvements. Fin inclination of γ=30 is found as the optimum inclination for achieving the highest power from the assembly. Higher inclination of elastic fin/PE-EH assembly results in cooling performance deterioration while average Nu reduces by a factor of 2.94 by varying inclination from γ=30 to γ=60 with nanofluid. For power generation, effects of using nanofluid with varying inclination is significant and EF becomes 252 from γ=0 to γ=30. There are opposing tendencies for the device’s power generation and cooling performance enhancement when the fin’s horizontal placement is changed. EF for average Nu is 7.25 for varying fin location. As the loading of nanoparticle inside the base fluid increases, the average Nu and generated power exhibit non-linear rising characteristics. Polynomial type correlations are provided for the average Nu and power from the device by varying elastic fin assembly inclination and nanoparticle solid volume fraction. Potential of using hybrid nanofluid in PE-EH embedded thermo-fluid system is shown. The design, development, and optimization of self-sufficient power production systems that may be used to various thermo-fluid systems, such as electronic cooling and thermal control in a range of heat transfer devices, may benefit from the findings.

The acoustic change complex evoked by location-change sounds in the elderly

Objective We have shown that the acoustic change complex (ACC) can be elicited by changing the horizontal sound location in young individuals. In this study, we aimed to evaluate the application of ACC within the elderly and its relationship with behavioural results. Design The minimum audible angle (MAA), as well as onset cortical auditory evoked potentials (onset-CAEPs) and ACC elicited by the stimuli of location-change white noise (±45 to ±2 degrees) were recorded. Latencies and amplitudes were analysed using repeated-measures ANOVA. Pearson correlation analysis was conducted to examine the relationship between ACC and MAA. Study sample Ten older adults with normal hearing (NH) and twenty with presbycusis. Results The ACC was effectively elicited with angular variations in elderly participants. The onset-CAEP N1 latency, ACC N1’-P2’ amplitude, and N1’ latency were all associated with the angle shifts, with the N1’ latency being the most predictive factor for angle discrimination. The consistency between MAA and ACC made them complementary for the clinical evaluation of sound localisation. Conclusions The utilisation of ACC, evoked by location-change sounds, presented a promising clinical objective measure for evaluating sound localisation abilities in the elderly.

Lateral-torsional buckling investigation of multi-tiers eccentrically braced frames with shear link beam

Multi-tiered braced frames (MTBF) are a type of braced frames with two or more tiers of bracing or bracing panels between horizontal diaphragm levels or locations of out-of-plane support, along with a beam at every tier level. They are commonly used in tall single-story building structures when it is not practical to use single bracing members spanning from roof to foundation levels. Additionally, they find application in multistory buildings with tall story heights. In this paper, lateral-torsional buckling of beams in a new type of MTBF called multi-tiered eccentrically braced frames (MT-EBF) is evaluated. This structural system is not mentioned in any of the current code and seismic criteria have not been provided. The main different of this system with eccentrically brace frame is the lack of laterally supported in the intermediate beam. Also, in industrial buildings that need architectural openings, this system is more useful than concentrically braced frame. For this purpose, the seismic behavior of four different MT-EBF with one and two tiers, along with two different configurations for the connection of braces to the beams, is studied. In the first configuration, the braces are connected to the beam using a gusset plate, and in the second configuration, the braces are directly connected to the beam using full penetration groove weld. The results of the numerical study indicate that in the first configuration, lateral-torsional buckling occurs in the intermediate beams, and the connection of the gusset plate to the beams lacks the necessary stiffness to prevent lateral-torsional buckling. However, in the second configuration, lateral-torsional buckling of the intermediate beams is prevented, and the connection of the braces to the beams has the adequate stiffness to prevent lateral-torsional buckling.

Aerial SfM–MVS Visualization of Surface Deformation along Folds during the 2024 Noto Peninsula Earthquake (Mw7.5)

This study aimed to map and analyze the spatial pattern of the surface deformation associated with the 2024 Noto Peninsula earthquake (Mw7.5) using structure-from-motion/multi-view-stereo (SfM–MVS), an advanced photogrammetric technique. The analysis was conducted using digital aerial photographs with a ground pixel dimension of 0.2 m (captured the day after the earthquake). Horizontal locations of GCPs were determined using pre-earthquake data to remove the wide-area horizontal crustal deformation component. The elevations of the GCPs were corrected by incorporating quasi-vertical values derived from a 2.5-dimensional analysis of synthetic aperture radar (SAR) results. In the synclinorium structure area, where no active fault had previously been identified, we observed a 5 km long uplift zone (0.1 to 0.2 km in width), along with multiple scarps that reached a maximum height of 2.2 m. The area and shape of the surface deformation suggested that the induced uplift and surrounding landslides were related to fold structures and their growth. Thus, our study shows the efficacy of SfM–MVS with respect to accurately mapping earthquake-induced deformations, providing crucial data for understanding seismic activity and informing disaster-response strategies.

Identifying failure connection area on wall for deep excavation based on system stiffness influence factor

In this study, a methodology to identify weak or failure connection area on the wall of deep excavation was proposed based on the system stiffness influence factor (IF), which can be beneficially utilized for wall-collapse prevention and forecasting system. Irregular excavation configuration common in urban areas and various weak-connection locations were considered. Three-dimensional finite element analyses with full consideration of actual staged excavation and strut-waler connection condition were performed. It was found that wall deflection and ground movement increased as the location of weak connection became deeper. It was also found that the influence of weak connection on the wall behavior became more pronounced as it located towards the center of the wall. The effects of weak connection on wall deflection were evaluated and quantified using IF. A modification procedure for IF was introduced to consider the effects of depth and horizontal weak-connection locations. The modified IF was adopted to establish a method for quantifying and identifying weak or failure connection area on the wall based on measured wall deflection from field monitoring. Case examples were selected to check the validity of the proposed method. The compared results showed that monitored and predicted locations of weak connection were in close agreement.

Clinical outcomes of ablation of gastric dysplasia with argon plasma coagulation.

Although several small cohort studies have shown the utility of argon plasma coagulation (APC) in the treatment of gastric dysplasia, its clinical significance has not been established. This study aims to assess the efficacy of APC as a first line treatment for gastric dysplasia, and identify risk factors for residual dysplasia. A total of 179 cases of gastric dysplasia were treated with APC and have been followed-up with upper endoscopy within 1 year. The overall incidence and the characteristics of lesions with residual dysplasia in follow-up endoscopy were analyzed by logistic regression. Among 179 lesions treated with APC, 171 (95.5%) lesions have achieved complete ablation in the follow-up endoscopy. Additional APC was applied for residual dysplasia, achieving complete ablation in 97.77% (175/179). The upper third location of the gastric dysplasia was significantly associated with residual dysplasia, while tumor size, horizontal location, macroscopic morphology and grade of dysplasia showed no significant associations with residual dysplasia following the initial APC. APC with meticulous follow-up can be recommended as a first line treatment in patients with gastric dysplasia.

Accelerating Seafloor Uplift of Submarine Caldera Near Sofugan Volcano, Japan, Resolved by Distant Tsunami Recordings

AbstractOn 8 October 2023 UTC, significant tsunamis were observed around Japan without any major tsunamigenic earthquake, associated with a series of 14 successive minor earthquakes (mb = 4.5–5.4) near Sofugan in the Izu‐Bonin Islands. To examine the cause of this tsunami, we estimated the horizontal locations of the tsunami source and temporal history of the seafloor displacement, using the tsunami data recorded by the ocean‐bottom pressure gauges >∼600 km away. Our results showed the main tsunami source was an uplift located at a caldera‐like bathymetric feature near Sofugan, suggesting the involvement of caldera activity in the tsunami generation. The total seafloor uplift was estimated as ∼4 m, and the uplift amount of each event gradually increased over time, reflecting an accelerating occurrence of volcanic unrest of the submarine caldera within only a few hours.

Mental foramen and apical foramen: A dangerous anatomical proximity.

The study evaluated the spatial position of the mental foramen (MF) using 300 cone-beam computed tomography. The spatial position was analyzed with the horizontal location and relative location (distance between apical foramen and MF). The horizontal location was assessed through three positions (positions 1, 2, and 3). The relative location was determined with the x, y, and x coordinates of the root apex of mandibular premolars and the MF. Student's t-test and chi-square were performed. The most common horizontal location (52%) was position 2, which means between the premolars (p < 0.05). The relative location of the MF to the root apex of the second premolar was closer than the first premolar (p < 0.05). The distance between the root tip of the second premolar and the MF was 5.27 mm, with a minimum value of 1.87 mm. Clinicians should be aware of the possible neural results to the mental nerve of an endodontic infection and the extrusion of irrigation solutions.

Effects of embedded walls on tunnelling-induced sandy ground displacements: a numerical investigation

Urban tunnelling projects pose significant risks to the integrity of nearby structures due to ground movements induced by the excavation process. Embedded walls are commonly employed as a protective measure to mitigate these adverse effects. This paper presents a comprehensive numerical investigation into the effects of embedded walls on tunnelling-induced ground displacements, aiming to provide insights and recommendations for optimal embedded wall design. The study assesses the impact of varying embedded wall length and horizontal distance from the tunnel on soil settlement and horizontal displacements. Results demonstrate the complex interplay between embedded wall length, horizontal distance and ground movement patterns, and the highly non-linear influence of key parameters on embedded wall efficiency (i.e. its ability to reduce settlements). A preliminary design chart is proposed to guide engineers in determining the appropriate horizontal location and depth of embedded walls to effectively reduce tunnelling-induced ground displacements. The findings contribute to a better understanding of embedded wall performance in the context of tunnelling and provide valuable guidance for the practical design and implementation of protective measures in urban areas.

Upgraded Low-Frequency 3D Lightning Mapping System in North China and Observations on Lightning Initiation Processes

The three-dimensional (3D) low-frequency lightning mapping system (LF-LMS) in north China has been updated. The lightning electric field derivative (dE/dt) sensor and continuous acquisition mode has been newly designed to ensure a capability of entire lightning processes detection, especially weak discharges during lightning the initiation process. The twice cross-correlation delay estimation and the grid iteration nested optimization location algorithm are used to realize the 3D location of the discharge channel, and the location resolution and calculation speed are balanced consequently. The location results of the rocket-triggered lightning demonstrated that the system achieved a high-resolution mapping of lightning discharge channels, which coincided well with the optical images. The horizontal and vertical location error for rocket triggered lightning was less than 40 m in both horizontal and vertical. Intracloud (IC) lightning flashes were observed to be initiated by three different discharge processes, initial breakdown pulse (IBP), narrow bipolar event (NBE), and initial E-change (IEC). The corresponding initial height was 10.5 km, 6.9 km, and 9.2 km, respectively. The upward negative leader was initially located, followed by scatter radiation sources and negative recoil leaders in the lower negative charge region for all cases. The electric field characteristics of the IEC and subsequent IBPs indicated that they are different discharge processes with the same current direction. The IEC process might correspond to the discharge process with continuous current and less noticeable current changes.

Modification of the Revised National Institute for Occupational Safety and Health (NIOSH) Lifting Equation to Determine the Individual Manual Lifting Risk in Malaysia's Manufacturing Industry.

The National Institute for Occupational Safety and Health (NIOSH) established the Revised NIOSH Lifting Equation (RNLE) for manual lifting risk assessment. The objectives of this study were to determine the characteristics of physical factors using the RNLE and to explore additional factors to RNLE by modifying it to an Individual Lifting Equation (ILE). This cross-sectional study was conducted in the manufacturing industry of three states in Malaysia among manual lifting workers. A questionnaire was administered, which comprised the sociodemographic characteristics and Nordic Musculoskeletal Questionnaire (NMQ) assessing low back pain (LBP). The RNLE dataset includes a load constant and six manual lifting variables collected from observational ergonomic risk assessment. The RNLE was modified to ILE by incorporating age, gender, and BMI. The equations' Lifting Index (LI) computed provides an overall manual lifting risk estimate. There were 165 participants, with a mean age of 28 years, and 108 (65.5%) were male. Most participants had a BMI within the normal range (60 (36.4%)) or were classified as overweight (54 (32.7%)). The lifting horizontal location showed the highest risk estimates, with the lowest meanmultiplier value of 0.55. In contrast, age and BMI had the lowest risk estimates, with mean multiplier values of 0.99 and 0.98, respectively. Among the participants, LI values of one or less, indicating very low risk, were observed in 58 (35.1%) for RNLE and 39 (23.6%) for ILE. Additionally, RNLE and ILE showed figures of 11 (6.7%) and 20 (12.1%), respectively, signifying a very high risk of LI exceeding three. Studying the lifting factors and equation multipliers from RNLE is critical for evaluating the risk estimates of manual lifting. Exploring the ILE based on individual characteristics is appropriate to support the ergonomic program. Further study is needed to validate the ILE as an accurate screening tool for determining LBP risk estimates.

Location Dictates Snow Aerodynamic Roughness

We conducted an experiment comparing wind speeds and aerodynamic roughness length (z0) values over three snow surface conditions, including a flat smooth surface, a wavy smooth surface, and a wavy surface with fresh snow added, using the wind simulation tunnel at the Shinjo Cryospheric Laboratory in Shinjo, Japan. The results indicate that the measurement location impacts the computed z0 values up to a certain measurement height. When we created small (4 cm high) snow bedforms as waves with a 50 cm period, the computed z0 values varied by up to 35% based on the horizontal sampling location over the wave (furrow versus trough). These computed z0 values for the smooth snow waves were not significantly different than those for the smooth flat snow surface. Fresh snow was then blown over the snow waves. Here, for three of four horizontal sampling locations, the computed z0 values were significantly different over the fresh snow-covered waves as compared to those over the smooth snow waves. Since meteorological stations are usually established over flat land surfaces, a smooth snow surface texture may seem to be an appropriate assumption when calculating z0, but the snowpack surface can vary substantially in space and time. Therefore, the nature of the snow surface geometry should be considered variable when estimating a z0 value, especially for modeling purposes.

Study on damage behavior of the outer horizontal target in the EAST lower divertor after plasma operations

The EAST lower divertor features a partially implemented flat-type structure, and visible damage has been observed, particularly at the outer horizontal target location after plasma operations. This study conducts a detailed analysis of the damage to the outer horizontal target. The findings reveal instances of plastic deformation, cracking, and even tungsten flake detachment at specific locations on the outer horizontal target. Furthermore, different degrees of recrystallization are identified in the tungsten plates after plasma operations, with a more pronounced effect closer to the surface of the tungsten plates. These observations offer pertinent insights for ongoing research into the microstructural enhancement design of tungsten materials and the enhancement of crack thresholds at the W/Cu interface.

Microseismic Event Location with Dual Vertical DAS Arrays: Insights from the FORGE 2022 Stimulation

Abstract We investigate the resolvability of a microseismic event location given a recording array composed of vertical distributed acoustic sensing (DAS) boreholes. We use a modified source-scanning algorithm that takes into account both P and S waves. We transform the brightness maps it produces into probability density functions (PDFs), over which we carry out a resolution and uncertainty analysis. We apply this approach to microseismic events recorded by two vertical DAS boreholes as part of the Frontier Observatory for Research in Geothermal Energy (FORGE) project. We show that for the specific acquisition geometry in FORGE, the horizontal location of the events cannot be determined, but their depth can, similar to results obtained with a single borehole. Using synthetic examples, we show that the recording array’s geometry is the limiting factor in the determination of the horizontal location. We investigate various possible recording geometries composed of idealized DAS-like vertical boreholes with varying locations and depths. We find that, besides the number of recordingd boreholes, their depth is the main factor influencing the location estimation uncertainty. The number and position of the boreholes mainly influence the spatial distribution of the PDF, whereas the boreholes’ depth mainly influences its size. Despite the simplicity of our analysis, it highlights the influence of the monitoring array design for microseismic events’ locating using vertical DAS arrays.