Visual Target Research Articles

Navigation of a Team of UAVs for Covert Video Sensing of a Target Moving on an Uneven Terrain

Unmanned aerial vehicles (UAVs) have become essential tools with diverse applications across multiple sectors, including remote sensing. This paper presents a trajectory planning method for a team of UAVs aimed at enhancing covert video sensing in uneven terrains and urban environments. The approach establishes a feasible flight zone, which dynamically adjusts to accommodate line of sight (LoS) occlusions caused by elevated terrains and structures between the UAVs’ sensors and the target. By avoiding ‘shadows’—projections of realistic shapes on the UAVs’ operational plane that represent buildings and other obstacles—the method ensures continuous target visibility. This strategy optimizes UAV trajectories, maintaining covertness while adapting to the changing environment, thereby improving overall video sensing performance. The method’s effectiveness is validated through comprehensive MATLAB simulations at both single and multiple UAV levels, demonstrating its ability to prevent LoS occlusions while preserving a high level of camouflage.

Evaluating the relationship between visual privacy and work-process interactions in open-plan offices: a space syntax approach

PurposePrevious studies on privacy in offices have primarily focused on the characteristics of generic visibility, examining the entire visible space from each workspace in 360 degrees. Nevertheless, employees in their workspaces investigate the visual targets within their binocular vision at 120 degrees. Therefore, by adopting the affordances perspective, this study aims to examine deeply generic and targeted visibility in open-plan offices and their relationship to interactions.Design/methodology/approachThe study consisted of two phases utilizing space syntax techniques. Initially, work-process interactions of the employees were determined through the survey. The survey data underwent spatial analysis to calculate the number of work-process interactions. Subsequently, DepthMapX software was used for visibility analyses. A new Python script for DepthMapX was developed to analyse the targeted visibility ratio. Multiple regression analyses were conducted to examine the relationship between the number of work-process interactions with generic and targeted visibility parameters.FindingsThe findings revealed that a higher number of visible employees within the 120-degree and 360-degree fields of vision corresponded to a lower number of work-process interactions in open-plan offices. Furthermore, the study establishes a direct link between visual privacy and interaction, indicating that increased visibility leads to decreased visual privacy.Originality/valueThe current research concluded that the relationship between visual privacy and interaction in open-plan offices differs from the previous studies, as employees with low visual privacy and high visibility tend to engage in fewer interactions. Overall, this study highlights that increased employee visibility is not directly associated with increased interaction in open-plan offices unless adequate visual privacy is provided.

Dynamics of EEG Synchronization and Desynchronization on Execution of Real and Imaginary Hand Movements Towards a Visible Target

Dynamics of EEG Synchronization and Desynchronization on Execution of Real and Imaginary Hand Movements Towards a Visible Target

Effect of detachment on Magnum-PSI ELM-like pulses: direct observations and qualitative results

Abstract Conditions similar to those at the end of the divertor leg in a tokamak were replicated in the linear plasma machine Magnum-PSI. The neutral pressure in the target chamber is then increased to cause the target to transition from an attached to a detached state. Superimposed to this steady state regime, edge localised mode (ELM)-like pulses are reproduced, resulting in a sudden increase in plasma temperature and density, such that the heat flux increases transiently by half an order of magnitude. Visible light emission, target thermography, and Thomson scattering are used to demonstrate that the higher the neutral pressure the more energy is removed from the ELM-like pulse in the volume. If the neutral pressure is sufficiently high, the ELM-like pulse can be prevented from affecting the target and the plasma energy is fully dissipated in the volume instead (ID 4 in table 1). The visible light images allow the division of the ELM-plasma interaction process of ELM energy dissipation into 3 ‘stages’ ranging from no dissipation to full dissipation (the target plasma is detached). In the second publication related to this study, spectroscopic data is analysed with a Bayesian approach, to acquire insights into the significance of molecular processes in dissipating the plasma energy and particles.

Impaired emotional multimodal integration in inhibition of return in children with attention-deficit/hyperactivity disorder.

Attention-deficit/hyperactivity disorder (ADHD) is a common neurodevelopmental disorder in children. Previous studies have shown that children with ADHD have impaired processing of emotional stimuli, but it is unclear whether their ability to integrate multimodal emotional stimuli is impaired and at which processing pathway this impairment exists. The present study investigated the ability of children with ADHD to integrate emotional audiovisual stimuli under different emotional conditions, and the effect of audiovisual integration on IOR to reveal the impaired processing pathway of their emotional audiovisual integration. Fifty-eight school-age children (29 with ADHD and 29 matched typically developing (TD) children) performed an emotional valence discrimination task with a cue-target paradigm. The results showed that children with ADHD did not exhibit audiovisual integration of emotional stimuli in all experimental conditions. In addition, the IOR effect was significantly smaller for audiovisual targets than for visual targets under the negative but not the neutral emotion condition in children with ADHD, whereas this effect was present in all emotion conditions in TD children. These results indicate that the ability to integrate emotional audiovisual information is impaired in children with ADHD and this impairment exists in both bottom-up and top-down pathways. Additionally, although presenting emotional auditory stimuli at the same time as emotional faces reduced IOR both in children with ADHD and TD, the manner of reduction differed. These findings provide new evidence of emotional processing deficits and multimodal integration deficits in children with ADHD, and help provide support for children in educational settings.

Visual Perceptual Confidence: Exploring Discrepancies Between Self-reported and Actual Distance Perception In Virtual Reality.

Virtual Reality (VR) systems are widely used, and it is essential to know if spatial perception in virtual environments (VEs) is similar to reality. Research indicates that users tend to underestimate distances in VR. Prior work suggests that actual distance judgments in VR may not always match the users self-reported preference of where they think they most accurately estimated distances. However, no explicit investigation evaluated whether user preferences match actual performance in a spatial judgment task. We used blind walking to explore potential dissimilarities between actual distance estimates and user-selected preferences of visual complexities, VE conditions, and targets. Our findings show a gap between user preferences and actual performance when visual complexities were varied, which has implications for better visual perception understanding, VR applications design, and research in spatial perception, indicating the need to calibrate and align user preferences and true spatial perception abilities in VR.

The Power of Trial History: How Previous Trial Shapes Audiovisual Integration

Abstract Combining information from visual and auditory modalities to form a unified and coherent perception is known as audiovisual integration. Audiovisual integration is affected by many factors. However, it remains unclear whether the trial history can influence audiovisual integration. We used a target–target paradigm to investigate how the target modality and spatial location of the previous trial affect audiovisual integration under conditions of divided-modalities attention (Experiment 1) and modality-specific selective attention (Experiment 2). In Experiment 1, we found that audiovisual integration was enhanced in the repeat locations compared with switch locations. Audiovisual integration was the largest following the auditory targets compared to following the visual and audiovisual targets. In Experiment 2, where participants were asked to focus only on visual, we found that the audiovisual integration effect was larger in the repeat location trials than switch location trials only when the audiovisual target was presented in the previous trial. The present results provide the first evidence that trial history can have an effect on audiovisual integration. The mechanisms of trial history modulating audiovisual integration are discussed. Future examining of audiovisual integration should carefully manipulate experimental conditions based on the effects of trial history.

Filtering on the Go: Effect of Filters on Gaze Pointing Accuracy During Physical Locomotion in Extended Reality.

Eye tracking filters have been shown to improve accuracy of gaze estimation and input for stationary settings. However, their effectiveness during physical movement remains underexplored. In this work, we compare common online filters in the context of physical locomotion in extended reality and propose alterations to improve them for on-the-go settings. We conducted a computational experiment where we simulate performance of the online filters using data on participants attending visual targets located in world-, path-, and two head-based reference frames while standing, walking, and jogging. Our results provide insights into the filters' effectiveness and factors that affect it, such as the amount of noise caused by locomotion and differences in compensatory eye movements, and demonstrate that filters with saccade detection prove most useful for on-the-go settings. We discuss the implications of our findings and conclude with guidance on gaze data filtering for interaction in extended reality.

Targeted Magnetic Nanoparticles for Beta-Amyloid Detection.

Background/Objectivities: The presence of beta-amyloid plaques is a part of the pathogenesis of Alzheimer's disease, but there is currently no universally accepted method for magnetic resonance (MR) imaging of the disease. However, it is known that magnetic nanoparticles (MNPs) can improve the T2 contrast in MR images of various targets. Methods: We used cubic MNPs, which were produced by thermal decomposition and then it was covalently bonded to a modified fluorescently labeled tetrapeptide, HAEE-Cy5, for visualizing beta-amyloid plaques. The interaction of MNPs-HAEE-Cy5 and beta-amyloid was determinate by confocal microscopy using SH-SY5Y cell line. Results: MNPs exhibit relatively high relaxivity (approximately 200 mM-1s-1), which is crucial for enhancing target visibility in MR imaging. HAEE provides targeted delivery of MNPs by specifically interacting with beta-amyloid, while the fluorescent label Cy5 enables monitoring the efficacy of the interaction through confocal microscopy. Conclusions: The MNPs modified with HAEE-Cy5 demonstrated excellent binding to beta-amyloid plaques in vitro, as shown by experiments on the SH-SY5Y cell line. These results suggest that the proposed method has potential for use in future MR imaging studies of Alzheimer's disease.

Mission Planning Method for Dense Area Target Observation Based on Clustering Agile Satellites

To address the mission planning challenge for agile satellites in dense point target observation, a clustering strategy based on an ant colony algorithm and a heuristic simulated genetic annealing optimization algorithm are proposed. First, the imaging observation process of agile satellites is analyzed, and an improved ant colony algorithm is employed to optimize the clustering of observation tasks, enabling the satellites to complete more observation tasks efficiently with a more stable attitude. Second, to solve for the optimal group target observation sequence and achieve higher total observation benefits, a task planning model based on multi-target observation benefits and attitude maneuver energy consumption is established, considering the visible time windows of targets and the time constraints between adjacent targets. To overcome the drawbacks of traditional simulated annealing and genetic algorithms, which are prone to local optimal solution and a slow convergence speed, a novel Simulated Genetic Annealing Algorithm is designed while optimizing the sum of target observation weights and yaw angles while also accounting for factors such as target visibility windows and satellite attitude transition times between targets. Ultimately, the feasibility and efficiency of the proposed algorithm are substantiated by comparing its performance against traditional heuristic optimization algorithms using a dataset comprising large-scale dense ground targets.

Eyes on nature: Embedded vision cameras for terrestrial biodiversity monitoring

Abstract We need comprehensive information to manage and protect biodiversity in the face of global environmental challenges, and artificial intelligence is required to generate that information from vast amounts of biodiversity data. Currently, vision‐based monitoring methods are heterogenous; they poorly cover spatial and temporal dimensions, overly depend on humans, and are not reactive enough for adaptive management. To mitigate these issues, we present a portable, modular, affordable and low‐power device with embedded vision for biodiversity monitoring of a wide range of terrestrial taxa. Our camera uses interchangeable lenses to resolve barely visible and remote targets, as well as customisable algorithms for blob detection, region‐of‐interest classification and object detection to automatically identify them. We showcase our system in six use cases from ethology, landscape ecology, agronomy, pollination ecology, conservation biology and phenology disciplines. Using the same devices with different setups, we discovered bats feeding on durian tree flowers, monitored flying bats and their insect prey, identified nocturnal insect pests in paddy fields, detected bees visiting rapeseed crop flowers, triggered real‐time alerts for waterfowl and tracked flower phenology over months. We measured classification accuracies (i.e. F1‐scores) between 55% and 95% in our field surveys and used them to standardise observations over highly resolved time scales. Our cameras are amenable to situations where automated vision‐based monitoring is required off the grid, in natural and agricultural ecosystems, and in particular for quantifying species interactions. Embedded vision devices such as this will help addressing global biodiversity challenges and facilitate a technology‐aided agricultural systems transformation.

Posture and vision: How different distances of viewing target affect postural stability and plantar pressure parameters in healthy population

BackgroundPostural stability is maintained by the Postural Control System (PCS), consisting of anatomical structures of Central Nervous System and peripheral receptors, interacting with each other, in order to keep whole-body balance by modulating the myofascial chains against gravity. The vision is one of the most important peripheral receptors for postural control. Previous studies analyzed the changes of body sway during viewing nearby (VNT) and distant (VDT) targets in healthy population without considering the feet adaptations related to the body weight distribution. Aim of this study was to investigate how different distances of viewing target affect the variability of postural stability and plantar pressure parameters in healthy subjects. Methods31 stabilometric and plantar pressure parameters were acquired in 20 young healthy subjects by baropodometry performed in bipedal standing during VNT and VDT (0.70 m and 3 m from the heels, respectively). Variability and statistical differences between VDT and VNT were implemented. ResultsResults showed the highest repeatability for plantar pressure parameters, a slightly high for CP speed and a lowest for CoPsa and Length Surface Function during both VNT and VDT. Moreover, a significant increase of load percentage on left-foot and right-Forefoot, of mean and maximum pressures on left-Forefoot, of CoPsa and CPspeed and a decrease of LSF were found during VDT. DiscussionThis study revealed how a greater distance of viewing target affects body-weight distribution and increases body oscillations. These findings highlighted the importance of visual target distance for the correct interpretation of postural stability and plantar pressure parameters, and the need to standardize target distance during stabilometric exam.

RECAPITULATING THE POST-SURGICAL BRAIN MICROENVIRONMENT OF ATYPICAL TERATOID RHABDOID TUMOURS TO IDENTIFY MEMBRANE PROTEINS FOR TARGETED THERAPY

Abstract AIMS Atypical Teratoid Rhabdoid Tumours (AT/RT) are rare aggressive tumours primarily arising in the hind brain of children under three, conferring median survival of <12 months. Surgery remains the only standard treatment; however tumours recur from post-surgical residual disease. Decellularised human brain cerebellum aim to recapitulate AT/RT post-surgical brain microenvironments which retain extracellular matrix (ECM) ligands, and where AT/RT plasma membrane proteins are hypothesised to represent viable molecular therapy targets. METHOD AT/RT, astrocyte and human brain cerebellum (decellularised and non-decellularised) membrane protein fractions were extracted and analysed using liquid chromatography-mass spectrometry. Proteomic analysis tools were integrated to identify differential expressed proteins and identify shared correlations. RESULTS Decellularised cerebellar ECM exhibited an enriched membrane proteome relative to total proteome, evidence of complete removal of intracellular components. Furthermore, decellularised and non-decellularised cerebellar tissue expressed comparable levels of membrane proteins and protein networks, indicative of ECM ligand retention. AT/RT and astrocyte KEGG Pathway analysis revealed specific oncology-based pathway expression in membrane protein compared to total protein, reinforcing membrane proteins as more visible therapeutic targets. Between the top 20 expressed proteins, ATP1A1 was the only membrane protein shared exclusively between all AT/RT cells and astrocytes, suggesting a critical functional role. Membrane proteins showing shared expression when normalised against each AT/RT cell line included ATP1A1, HSPD1, GNA13 and SLC3A2, indicating biological similarities between AT/RT molecular subtypes, which may offer candidate ubiquitous therapy targets. Membrane proteins expressed similarly in AT/RT-MYC molecular subtypes include ATP1A1, SLC7A5 and EEF1A1. STRING membrane pathway analysis also identified shared proteins between AT/RT and astrocyte cell populations. CONCLUSION AT/RT membrane protein pathways provide ideal therapeutic targets directly amenable for drug repurposing. Future work prioritises proteomic analysis utilising 3D AT/RT spheroids and cerebellum brain tissue to maximise accurately recapitulating the AT/RT post-surgical microenvironment. Cerebellum decellularisation still permits retention of essential proteins and ligands.

Optimal visual control of tendon-sheath-driven continuum robots with robust Jacobian estimation in confined environments

Accurate control of continuum robots in confined environments presents a significant challenge due to the need for a precise kinematic model, which is susceptible to external interference. This paper introduces a model-less optimal visual control (MLOVC) method that enables a tendon-sheath-driven continuum robot (TSDCR) to effectively track visual targets in a confined environment while ensuring stability. The method allows for intraluminal navigation of TSDCRs along narrow lumens. To account for the presence of external outliers, a robust Jacobian estimation method is proposed, wherein improved iterative reweighted least squares with sliding windows are used to online calculate the robot’s Jacobian matrix from sensing data. The estimated Jacobian establishes the motion relationship between the visual feature and the actuation. Furthermore, an optimal visual control method based on quadratic programming (QP) is designed for visual target tracking, while considering the robot’s physical constraint and control constraints. The MLOVC method for visual tracking provides a reliable alternative that does not rely on the precise kinematics of TSDCRs and takes into consideration the impact of outliers. The control stability of the proposed approach is demonstrated through Lyapunov analysis. Simulations and experiments are conducted to evaluate the effectiveness of the MLOVC method, and the results demonstrate that it enhances tracking performance in terms of accuracy and stability.

SFFN: Serial Feature Fusion Network for Visual Tracking

Abstract Recently, The Transformer tracker has excellent visual target tracking performance. The parallel arrangement of structural feature fusion networks proposed by the TransT tracker makes the Transformer learn the erroneous information. To address the issue, this paper proposes the SFFN tracker. It constructed a serial feature fusion network with the Transformer module in a serial interleaved arrangement to avoid learning erroneous information during the Transformer feature fusion process. The experiments show that SFFN performs well on the GOT-10k dataset, and it improves over TransT by 2.6%, 2.6%, and 2.3% in AO, SR0.5, and SR0.75, respectively.

Audiovisual Integration Decreases Inhibition of Return in Children With ADHD

Objectives: Previous studies have widely demonstrated that inhibition of return (IOR) with audiovisual targets decreases due to audiovisual integration (AVI). It is currently unclear, however, whether the impaired AVI in children with ADHD has effects on IOR. The present study used the cue-target paradigm to explore differences between the IOR of audiovisual targets and the IOR of visual targets in ADHD and typically developing (TD) children. Method: A total of 81 native Chinese speakers aged 6 to 13 years were recruited, including 38 children with ADHD and 43 age- and sex-matched TD children. Results: The results showed that there was a smaller magnitude of IOR with audiovisual targets as compared with visual targets in the two groups. Importantly, the reduction of IOR in audiovisual conditions was significantly smaller in children with ADHD than in children with TD. Race model analyses further confirmed that differences in IOR between ADHD and TD are due to deficits of audiovisual integration in ADHD. Conclusion: The results indicated that children with ADHD have impaired audiovisual integration, which has a minimal impact on IOR.

Unveiling the power of Haar frequency domain: Advancing small target motion detection in dim light

Visual small target motion detection finds successful applications in varied scenarios. However, dim-light conditions, such as the tunnel scenes and nighttime environments, present significant challenges to existing detection methods which mainly operate within the spatiotemporal domain. This is because the transmission of small target motion information suffers from the inevitable interference of image noise caused by dim light in the spatiotemporal domain, resulting in the detriment of extracting essential spatiotemporal features of the target motion. Given the significant obstacles posed by dim-light imaging to small target motion detection within the spatiotemporal domain, the exploration of an alternative observation domain for small target motion, alongside the development of a corresponding detection method, emerges as a viable solution. To address this, in this paper, we discovered the remarkable potential of the Haar frequency domain in characterizing the small target motion in dim light. To investigate the advantages of integrating Haar frequency processing in small target motion detection, we introduce a Haar-windowed summation mechanism into an existing bio-inspired small target motion detection model. The proposed mechanism integrates visual information in spatiotemporal windows regulated by frequency parameters of Haar wavelets and effectively discriminates the small target motion from the disturbance of random noise caused by dim light. Theoretical analysis and numerical experiments confirm the superior performance of integrating the Haar frequency processing. This study provides a new vision of small target motion detection through the lens of the frequency domain and extends the limits of existing bio-inspired models for practical applications in dim light.

Simulation of indoor space thermal energy circulation in architectural environment design detail features based on visual object tracking algorithm

The heat circulation of interior space plays a crucial role in the design of the built environment, affecting energy efficiency and residential comfort. With the development of science and technology, visual target tracking algorithm provides a new possibility for optimizing thermal energy cycle. The purpose of this paper is to study the simulation method of indoor space thermal energy cycle based on visual target tracking algorithm to improve the efficiency of thermal energy management in building environment design and ensure indoor comfort. The research uses laboratory Settings, combined with high-performance cameras and advanced visual target tracking algorithms, to monitor indoor heat source distribution and personnel movement in real time. Through data acquisition and analysis, the indoor heat cycle model was constructed and simulated by computational fluid dynamics (CFD) software to evaluate the influence of different design parameters on the heat cycle. Through the optimization of the design scheme, the efficiency of indoor heat use is significantly improved, and the comfort score of residents is significantly improved. Therefore, the simulation of indoor space thermal energy cycle based on visual target tracking algorithm provides an effective tool for building environment design, which can realize efficient energy management and improve living comfort.

The Effect of Congruent versus Incongruent Distractor Positioning on Electrophysiological Signals during Perceptual Decision-Making.

Key event-related potentials (ERPs) of perceptual decision-making such as centroparietal positivity (CPP) elucidate how evidence is accumulated toward a given choice. Furthermore, this accumulation can be impacted by visual target selection signals such as the N2 contralateral (N2c). How these underlying neural mechanisms of perceptual decision-making are influenced by the spatial congruence of distractors relative to target stimuli remains unclear. Here, we used electroencephalography (EEG) in humans of both sexes to investigate the effect of distractor spatial congruency (same vs different hemifield relative to targets) on perceptual decision-making. We confirmed that responses for perceptual decisions were slower for spatially incongruent versus congruent distractors of high salience. Similarly, markers of target selection (N2c peak amplitude) and evidence accumulation (CPP slope) were found to be lower when distractors were spatially incongruent versus congruent. To evaluate the effects of congruency further, we applied drift diffusion modeling to participant responses, which showed that larger amplitudes of both ERPs were correlated with shorter nondecision times when considering the effect of congruency. The modeling also suggested that congruency's effect on behavior occurred prior to and during evidence accumulation when considering the effects of the N2c peak and CPP slope. These findings point to spatially incongruent distractors, relative to congruent distractors, influencing decisions as early as the initial sensory processing phase and then continuing to exert an effect as evidence is accumulated throughout the decision-making process. Overall, our findings highlight how key electrophysiological signals of perceptual decision-making are influenced by the spatial congruence of target and distractor.

Visual Target Interaction Modeling with Multichannel Data Fusion

Facing the demand for accurate, fast, and natural human–computer interaction in the multi-screen control environment, the traditional exchange method of frequent switching control of multi-screen through mouse, keyboard, and other manual methods has problems of low efficiency, weak flexibility, and poor experience. In this paper, we research multi-screen precision control technology based on eye movement to break through the difficulties of precise recognition of human vision under complex environments and poor stability of vision estimation under frequent switching control of multi-screen. This study explores the technology for controlling multiple screens with high precision by tracking eye movements. It overcomes the challenges associated with reliably discerning human visual focus in intricate settings and the instability of visual assessments during rapid transitions between multiple screens. The experimental results of 1143 eye-movement capture tasks are studied, including the accurate recognition technology of human head posture and pupil gaze direction under complex backgrounds, illumination, and different visual field environments, and the theoretical modeling method of multi-screen precise target interaction based on eye-movement is explored. The expression data will be processed using convolutional neural networks, and the dataset will be trained through Python programming and tested on test samples collected by simulated flight crews in the laboratory with an accuracy rate of more than 85%.