Three-dimensional Visualization Research Articles

Attention-driven visual emphasis for medical volumetric image visualization

AbstractDirect volume rendering (DVR) is a commonly utilized technique for three-dimensional visualization of volumetric medical images. A key goal of DVR is to enable users to visually emphasize regions of interest (ROIs) which may be occluded by other structures. Conventional methods for ROIs visual emphasis require extensive user involvement for the adjustment of rendering parameters to reduce the occlusion, dependent on the user’s viewing direction. Several works have been proposed to automatically preserve the view of the ROIs by eliminating the occluding structures of lower importance in a view-dependent manner. However, they require pre-segmentation labeling and manual importance assignment on the images. An alternative to ROIs segmentation is to use ‘saliency’ to identify important regions. This however lacks semantic information and thus leads to the inclusion of false positive regions. In this study, we propose an attention-driven visual emphasis method for volumetric medical image visualization. We developed a deep learning attention model, termed as focused-class attention map (F-CAM), trained with only image-wise labels for automated ROIs localization and importance estimation. Our F-CAM transfers the semantic information from the classification task for use in the localization of ROIs, with a focus on small ROIs that characterize medical images. Additionally, we propose an attention compositing module that integrates the generated attention map with transfer function within the DVR pipeline to automate the view-dependent visual emphasis of the ROIs. We demonstrate the superiority of our method compared to existing methods on a multi-modality PET-CT dataset and an MRI dataset.

Imaging Biomarkers of Oral Dysplasia and Carcinoma Measured with In Vivo Endoscopic Optical Coherence Tomography.

Optical coherence tomography is a noninvasive imaging technique that provides three-dimensional visualization of subsurface tissue structures. OCT has been proposed and explored in the literature as a tool to assess oral cancer status, select biopsy sites, or identify surgical margins. Our endoscopic OCT device can generate widefield (centimeters long) imaging of lesions at any location in the oral cavity-but it is challenging for raters to quantitatively assess and score large volumes of data. Leveraging a previously developed epithelial segmentation network, this work develops quantifiable biomarkers that provide direct measurements of tissue properties in three dimensions. We hypothesize that features related to morphology, tissue attenuation, and contrast between tissue layers will be able to provide a quantitative assessment of disease status (dysplasia through carcinoma). This work retrospectively assesses seven biomarkers on a lesion-contralateral matched OCT dataset of the lateral and ventral tongue (40 patients, 70 sites). Epithelial depth and loss of epithelial-stromal boundary visualization provide the strongest discrimination between disease states. The stroma optical attenuation coefficient provides a distinction between benign lesions from dysplasia and carcinoma. The stratification biomarkers visualize subsurface changes, which provides potential for future utility in biopsy site selection or treatment margin delineation.

A Visual Environment for Data Driven Protein Modeling and Validation.

In structural biology, validation and verification of new atomic models are crucial and necessary steps which limit the production of reliable molecular models for publications and databases. An atomic model is the result of meticulous modeling and matching and is evaluated using a variety of metrics that provide clues to improve and refine the model so it fits our understanding of molecules and physical constraints. In cryo electron microscopy (cryo-EM) the validation is also part of an iterative modeling process in which there is a need to judge the quality of the model during the creation phase. A shortcoming is that the process and results of the validation are rarely communicated using visual metaphors. This work presents a visual framework for molecular validation. The framework was developed in close collaboration with domain experts in a participatory design process. Its core is a novel visual representation based on 2D heatmaps that shows all available validation metrics in a linear fashion, presenting a global overview of the atomic model and provide domain experts with interactive analysis tools. Additional information stemming from the underlying data, such as a variety of local quality measures, is used to guide the user's attention toward regions of higher relevance. Linked with the heatmap is a three-dimensional molecular visualization providing the spatial context of the structures and chosen metrics. Additional views of statistical properties of the structure are included in the visual framework. We demonstrate the utility of the framework and its visual guidance with examples from cryo-EM.

Phase-contrast visualization of human tissues using superimposed wavefront imaging of diffraction-enhanced x-rays.

Phase-contrast computed tomography (CT) using high-brilliance, synchrotron-generated x-rays enable three-dimensional (3D) visualization of microanatomical structures within biological specimens, offering exceptionally high-contrast images of soft tissues. Traditional methods for phase-contrast CT; however, necessitate a gap between the subject and the x-ray camera, compromising spatial resolution due to penumbral blurring. Our newly developed technique, Superimposed Wavefront Imaging of Diffraction-enhanced x-rays (SWIDeX), leverages a Laue-case Si angle analyzer affixed to a scintillator to convert x-rays to visible light, capturing second-order differential phase contrast images and effectively eliminating the distance to the x-ray camera. This innovation achieves superior spatial resolution over conventional methods. In this paper, the imaging principle and CT reconstruction algorithm based on SWIDeX are presented in detail and compared with conventional analyzer-based imaging (ABI). It also shows the physical setup of SWIDeX that provides the resolution preserving second-order differential images for reconstruction. We compare the spatial resolution and the sensitivity of SWIDeX to conventional ABI. To demonstrate high-spatial resolution achievable by SWIDeX, the internal structures of four human tissues-ductal carcinoma in situ, normal stomach, normal pancreas, and intraductal papillary mucinous neoplasm of the pancreas-were visualized using an imaging system configured at the Photon Factory's BL14B beamline under the High Energy Accelerator Research Organization (KEK). Each tissue was thinly sliced after imaging, stained with hematoxylin and eosin (H&E) for conventional microscope-based pathology. A comparison of SWIDeX-CT and pathological images visually demonstrates the effectiveness of SWIDeX-CT for biological tissue imaging. SWIDeX could generate clearer 3D images than existing analyzer-based phase-contrast methods and accurately delineate tissue structures, as validated against histopathological images. SWIDeX can visualize important 3D structures in biological soft tissue with high spatial resolution and can be an important tool for providing information between the disparate scales of clinical and pathological imaging.

Segmental Bowel Resection for Rectal Endometriosis Using the da Vinci SP

ObjectiveThe da Vinci SP Surgical System (SP) received regulatory approval for use in gynecological surgeries in Japan in 2023. Given the advantages of the precision of a robot, less pain, and the cosmesis of single-port surgery, the da Vinci SP is expected to be further used for minimally invasive surgeries. To the best of our knowledge, this is the first report of the use of SP for the treatment of rectal endometriosis with segmental bowel resection. SettingAn urban general hospital. Stepwise demonstration of the technique with narrated video footage. ParticipantsThe patient was a 46-year-old woman presented with chronic pelvic pain, pain on defecation, and constipation. Magnetic resonance imaging showed uterine large fibroid, left ovarian endometrioma, and 38 mm of rectal endometriosis, with complete cul-de-sac obliteration. InterventionsWe made a 30-mm vertical incision at the umbilicus, then placed the access port, and inserted three articulating instruments and a camera. An assistant port was placed in the right lower quadrant for using the linear stapler. The surgical steps were completely identical to conventional multiport laparoscopic robotic surgery. This suggests that conventional laparoscopic or robotic skills are highly transferrable to SP. SP offer several advantages, including high-resolution three-dimensional visualization, articulating instruments, and improved dexterity and range of motion. In addition, the umbilical access port was particularly useful for proximal bowel resection, specimen retrieval, and anvil positioning during bowel resection. The total operative time was 216 minutes. The estimated blood loss was 100 ml without any complications. The uterine weight was 800 g. The postoperative course was uneventful, with no perioperative complications, including no postoperative bladder dysfunction or low anterior resection syndrome [1,2]. ConclusionThe use of SP with the access port for segmental bowel resection for rectal endometriosis is technically safe and feasible, with good cosmesis and less pain.

MAGPIE: An interactive tool for visualizing and analyzing protein-ligand interactions.

Quantitative tools to compile and analyze biomolecular interactions among chemically diverse binding partners would improve therapeutic design and aid in studying molecular evolution. Here we present Mapping Areas of Genetic Parsimony In Epitopes (MAGPIE), a publicly available software package for simultaneously visualizing and analyzing thousands of interactions between a single protein or small molecule ligand (the "target") and all of its protein binding partners ("binders"). MAGPIE generates an interactive three-dimensional visualization from a set of protein complex structures that share the target ligand, as well as sequence logo-style amino acid frequency graphs that show all the amino acids from the set of protein binders that interact with user-defined target ligand positions or chemical groups. MAGPIE highlights all the salt bridge and hydrogen bond interactions made by the target in the visualization and as separate amino acid frequency graphs. Finally, MAGPIE collates the most common target-binder interactions as a list of "hotspots," which can be used to analyze trends or guide the de novo design of protein binders. As an example of the utility of the program, we used MAGPIE to probe how different antibody fragments bind a viral antigen; how a common metabolite binds diverse protein partners; and how two ligands bind orthologs of a well-conserved glycolytic enzyme for a detailed understanding of evolutionarily conserved interactions involved in its activation and inhibition. MAGPIE is implemented in Python 3 and freely available at https://github.com/glasgowlab/MAGPIE, along with sample datasets, usage examples, and helper scripts to prepare input structures.

Three-dimensional visualization technology for guiding one-step percutaneous transhepatic cholangioscopic lithotripsy for the treatment of complex hepatolithiasis.

Biliary stone disease is a highly prevalent condition and a leading cause of hospitalization worldwide. Hepatolithiasis with associated strictures has high residual and recurrence rates after traditional multisession percutaneous transhepatic cholangioscopic lithotripsy (PTCSL). To study one-step PTCSL using the percutaneous transhepatic one-step biliary fistulation (PTOBF) technique guided by three-dimensional (3D) visualization. This was a retrospective, single-center study analyzing, 140 patients who, between October 2016 and October 2023, underwent one-step PTCSL for hepatolithiasis. The patients were divided into two groups: The 3D-PTOBF group and the PTOBF group. Stone clearance on choledochoscopy, complications, and long-term clearance and recurrence rates were assessed. Age, total bilirubin, direct bilirubin, Child-Pugh class, and stone location were similar between the 2 groups, but there was a significant difference in bile duct strictures, with biliary strictures more common in the 3D-PTOBF group (P = 0.001). The median follow-up time was 55.0 (55.0, 512.0) days. The immediate stone clearance ratio (88.6% vs 27.1%, P = 0.000) and stricture resolution ratio (97.1% vs 78.6%, P = 0.001) in the 3D-PTOBF group were significantly greater than those in the PTOBF group. Postoperative complication (8.6% vs 41.4%, P = 0.000) and stone recurrence rates (7.1% vs 38.6%, P = 0.000) were significantly lower in the 3D-PTOBF group. Three-dimensional visualization helps make one-step PTCSL a safe, effective, and promising treatment for patients with complicated primary hepatolithiasis. The perioperative and long-term outcomes are satisfactory for patients with complicated primary hepatolithiasis. This minimally invasive method has the potential to be used as a substitute for hepatobiliary surgery.

3D dynamic landscape simulation of artificial intelligence in environmental landscape design

Three-dimensional (3D) simulations and precise landscape visualizations are crucial for various applications, like landscape management and planning, computer and connection of the landscape, evaluation, and tracking of land use. The consequences of several plans and a large scene cannot be communicated using older methods of comprehensive environmental planning and development in a timely, rational, and coordinated manner. Architects have trouble incorporating ideas into other comprehensive planning implementation processes. Architects did not thoroughly investigate the neighbourhood's demographics and matching behavioural needs and lacked critical thinking. The 3D dynamic landscape simulation is a detailed computerized three-dimensional simulation of the environment that can be dynamically presented. With the aid of Artificial Intelligence (AI) technology, the system possesses a strong sense of reality, a user-friendly interface, and interactive features that can be tailored to the requirements of the contemporary urban environmental landscape. Regarding exterior publicity, domestic assistance, environmental land use planning, and information systems. The novelty of the proposed Interactive Design System based on AI (IDS-AI) is to create a 3D dynamic landscape model based on a real-life environmental scene, utilizing a Geographic Information System (GIS) to optimize landscape vision. Secondly, 3D environmental landscape design simulation was implemented using GIS spatial analysis in conjunction with the Fuzzy Analytical Hierarchical Process (FAHP) to reduce the data overlap rate and help make an accurate decision. Finally, the design incorporates the development of the interactive interface system application of landscape design and environmental resources for viewing the landscape, the factors that affect them, and the area coverage ratio of various land cover types. The experimental outcomes show that the suggested IDS model increases the gradient sensitivity level of 98.3 % and area coverage ratio of 93.4 % compared to other existing models.

Advancing Precision Rhinoplasty: Preoperative Digital 3D Surgical Planning.

The aim of the study is to assess the efficacy and advantages of utilizing state-of-the-art three-dimensional (3D) reconstruction technology in preoperative planning for rhinoplasty surgery. It is a study of a single rhinoplasty case that was operated at a tertiary hospital. The patient was assessed through a detailed history, blood investigations, radiological investigations and preoperative 3D (three-dimensional) reconstruction of the face and nose. The study utilized high-resolution CT scans and 3D reconstruction software like 3D (three-dimensional) Slicer and Blender 3D (three-dimensional) to analyze nasal anatomy for preoperative planning in rhinoplasty. External and internal nasal measurements were taken, and axial cross-section analysis was conducted to assess nasal structure deviation. The benefits of 3D (three-dimensional) visualization in surgical planning were evaluated, and surgical management was based on preoperative reconstructions. Comprehensive preoperative evaluations were performed, adhering to ethical guidelines.Preoperative 3D (three-dimensional) reconstruction planning methods facilitated precise surgical planning and execution in rhinoplasty with satisfactory outcomes for both the patient and the surgeon. Incorporating 3D (three-dimensional) reconstruction technology in rhinoplasty preoperative planning enhances surgical precision and patient satisfaction, ensuring optimized surgical outcomes while adhering to ethical standards.

Three-Dimensional Cell Culture Micro-CT Visualization within Collagen Scaffolds in an Aqueous Environment.

Among all of the materials used in tissue engineering in order to develop bioequivalents, collagen shows to be the most promising due to its superb biocompatibility and biodegradability, thus becoming one of the most widely used materials for scaffold production. However, current imaging techniques of the cells within collagen scaffolds have several limitations, which lead to an urgent need for novel methods of visualization. In this work, we have obtained groups of collagen scaffolds and selected the contrasting agents in order to study pores and patterns of cell growth in a non-disruptive manner via X-ray computed microtomography (micro-CT). After the comparison of multiple contrast agents, a 3% aqueous phosphotungstic acid solution in distilled water was identified as the most effective amongst the media, requiring 24 h of incubation. The differences in intensity values between collagen fibers, pores, and masses of cells allow for the accurate segmentation needed for further analysis. Moreover, the presented protocol allows visualization of porous collagen scaffolds under aqueous conditions, which is crucial for the multimodal study of the native structure of samples.

Three-Dimensional Reconstruction and Visualization of Underwater Bridge Piers Using Sonar Imaging.

The quality of underwater bridge piers significantly impacts bridge safety and long-term usability. To address limitations in conventional inspection methods, this paper presents a sonar-based technique for the three-dimensional (3D) reconstruction and visualization of underwater bridge piers. Advanced MS1000 scanning sonar is employed to detect and image bridge piers. Automated image preprocessing, including filtering, denoising, binarization, filling, and morphological operations, introduces an enhanced wavelet denoising method to accurately extract the foundation contour coordinates of bridge piers from sonar images. Using these coordinates, along with undamaged pier dimensions and sonar distances, a model-driven approach for a 3D pier reconstruction algorithm is developed. This algorithm leverages multiple sonar data points to reconstruct damaged piers through multiplication. The Visualization Toolkit (VTK) and surface contour methodology are utilized for 3D visualization, enabling interactive manipulation for enhanced observation and analysis. Experimental results indicate a relative error of 13.56% for the hole volume and 10.65% for the spalling volume, demonstrating accurate replication of bridge pier defect volumes by the reconstructed models. Experimental validation confirms the method's accuracy and effectiveness in reconstructing underwater bridge piers in three dimensions, providing robust support for safety assessments and contributing significantly to bridge stability and long-term safety assurance.

GPU-accelerated OCT imaging: Real-time data processing and artifact suppression for enhanced monitoring of 3D bioprinted tissues and vascular-like networks

Optical coherence tomography (OCT) imaging technology has significant advantages in in situ and noninvasive monitoring of biological tissues. However, it still faces the following challenges: including data processing speed, image quality, and improvements in three-dimensional (3D) visualization effects. OCT technology, especially functional imaging techniques like optical coherence tomography angiography (OCTA), requires a long acquisition time and a large data size. Despite the substantial increase in the acquisition speed of swept source optical coherence tomography (SS-OCT), it still poses significant challenges for data processing. Additionally, during in situ acquisition, image artifacts resulting from interface reflections or strong reflections from biological tissues and culturing containers present obstacles to data visualization and further analysis. Firstly, a customized frequency domain filter with anti-banding suppression parameters was designed to suppress artifact noises. Then, this study proposed a graphics processing unit (GPU)-based real-time data processing pipeline for SS-OCT, achieving a measured line-process rate of 800[Formula: see text]kHz for 3D fast and high-quality data visualization. Furthermore, a GPU-based real-time data processing for CC-OCTA was integrated to acquire dynamic information. Moreover, a vascular-like network chip was prepared using extrusion-based 3D printing and sacrificial materials, with sacrificial material being printed at the desired vascular network locations and then removed to form the vascular-like network. OCTA imaging technology was used to monitor the progression of sacrificial material removal and vascular-like network formation. Therefore, GPU-based OCT enables real-time processing and visualization with artifact suppression, making it particularly suitable for in situ noninvasive longitudinal monitoring of 3D bioprinting tissue and vascular-like networks in microfluidic chips.

Welding load, temperature, and material flow in ultrasonic vibration enhanced friction stir lap welding of aluminum alloy to steel

To elucidate the effect of ultrasonic vibration on the welding process (welding load, thermal cycle, and material flow) of aluminum/steel dissimilar metals in friction stir lap welding, conventional friction stir lap welding (FSLW) and ultrasonic vibration enhanced friction stir lap welding (U-FSLW) were used to weld aluminum/steel dissimilar metals. The results indicate that applying ultrasonic vibration to the FSLW of aluminum/steel dissimilar metals can effectively decrease welding loads (tool torque, axial force, and spindle power), and it was found that the reduction in welding load was inversely proportional to the welding speed. The effect of additional ultrasonic vibration on axial force was the largest. Ultrasonic vibration had a significant preheating effect, and its thermal effect in the width and depth directions of the workpiece gradually weakened. Additional ultrasound can reduce the peak temperature during the welding process. The instantaneous state of the weld was obtained using the "emergency stop+emergency cooling" technology, and the three-dimensional visualization characterization of material flow near the keyhole was achieved using X-ray based computer tomography (CT). It was found that ultrasonic vibration could increase the material's plastic flow, change the steel structure's flow path, and significantly increase the steel particles' flow range near the pin tool. Compared with conventional FSLW, the changes in the macro/microstructure of U-FSLW joints were closely related to the welding thermal cycle and material flow.

Chip-scale integrated holographic devices based on top-emitting vertical cavity surface emitting lasers.

Holography technology is considered the ultimate three-dimensional (3D) visualization technology in the future. However, conventional methods for achieving holography generally utilize discrete optical components and off-chip laser sources, resulting in a large size and high complexity, which are undesirable for practical applications. In this Letter, chip-scale integrated holographic devices are realized by integrating top-emitting vertical cavity surface emitting lasers (VCSELs) with micro holograms printed by 3D femtosecond laser nanoprinting technology. The VCSELs are designed to operate in a single fundamental mode with a Gaussian emission profile. Then the Gaussian beams are phase-modulated by the integrated micro holograms designed by the Gerchberg-Saxton (GS) algorithm and the target holographic images can be displayed behind the holograms. Such integrated holographic devices are of micron size and can be easily scaled into arrays with arbitrary channels on-demand, which are important for achieving miniaturized and portable holographic imaging systems.

The skull of the Turks and Caicos rock iguana, Cyclura carinata (Squamata: Iguanidae).

We provide a detailed and first description of the skull, hyoid apparatus, and trachea of the Turks and Caicos rock iguana, Cyclura carinata (Squamata: Iguanidae). Cyclura is a radiation of iguanas restricted to islands of the Caribbean Sea. Species of Cyclura have high rates of endemism, and all species are severely threatened with extinction. Our anatomical description of this threatened iguana is based on high-resolution computed tomography scans of one adult, one putative adult or near adult, and one juvenile specimen, and includes three-dimensional segmented renderings and visualizations. We discuss some observations of intraspecific and ontogenetic variation, and provide a brief comparison with specimens of another species of Cyclura and published descriptions of other iguanas. Our study provides a cranial osteological framework for Cyclura and augments the body of knowledge on iguana anatomy generally. Finally, we posit that our description and future studies may facilitate identification of fossil Cyclura, which could help understand the paleobiogeography of the genus.

Integrating Artificial Intelligence Into the Visualization and Modeling of Three-Dimensional Anatomy in Pediatric Surgical Patients

BackgroundPediatric surgeons often treat patients with complex anatomical considerations due to congenital anomalies or distortion of normal structures by solid organ tumors. There are multiple applications for three-dimensional visualization of these structures based on cross-sectional imaging. Recently, advances in artificial intelligence (AI) applications and graphics hardware have made rapid 3D modelling of individual structures within the body accessible to surgeons without sophisticated and expensive hardware. In this report, we provide an overview of these applications and their uses in preoperative planning for pediatric surgeons. MethodsDeidentified DICOM files containing cross-sectional imaging of preoperative pediatric surgery patients were loaded from an institutional PACS database onto a secure PC with dedicated graphics and AI hardware (NVIDIA Geforce RTX 4070 laptop GPU). Visualization was obtained using an open-source imaging platform (3D Slicer). AI extensions to the platform were utilized to delineate the anatomy of interest. ResultsSegmentations of skeletal and visceral structures within a scan were obtained using the TotalSegmentator extension with an average processing time under 5 min. Additional AI modules were utilized for providing detailed mapping of the airways (AirwaySegmentation), lungs (Chest Imaging Platform), liver (SlicerLiver), or vasculature (SlicerVMTK). Other extensions were used for delineation of tumors within the hepatic parenchyma (MONAI Auto3DSeg) and hepatic vessels (RVesselX). ConclusionAI algorithms for image interpretation and processors dedicated to AI functions have significantly decreased the technical and financial requirements for obtaining detailed three-dimensional images of patient anatomy. Models obtained using AI algorithms have potential applications in preoperative planning, surgical simulation, patient education, and training. Level of EvidenceV, Case Series, Description of Technique.

Comparison analysis of moisture-dependent orthotropic elasticity between earlywood and latewood in Chinese fir using digital image correlation

Given its orthotropic and hygroscopic nature, Chinese fir exhibits varying mechanical behaviors in earlywood and latewood due to its naturally inhomogeneous structure when exposed to changes in loading direction and given moisture content (MC) range from 7.9 % to 16.1 %. In this study, we combined micro-tensile testing and the digital image correlation (DIC) technique to derive the moisture -dependent orthotropic elastic constants, i.e., Young’s modulus (E), Poisson’s ratio (ν) and shear modulus (G) for both earlywood and latewood in Chinese fir. The findings revealed that when loading in the parallel direction, the restraining effect caused by latewood on earlywood resulted in a difference compared with loading in series. Interestingly, the loading direction impacted the restraining effect more significantly than MC. Additionally, both Young’s modulus and shear modulus exhibited decreases with increasing MC within above range for both earlywood and latewood. Notably, the Young’s modulus of earlywood showed a higher sensitivity to MC variations compared to latewood. However, Poisson’s ratio did not consistently correlate with MC within above range in all orthotropic directions. A three-dimensional coordinate system visualization of the compliance parameters highlighted the differing sensitivities of earlywood and latewood to moisture. The independent moisture-dependent elastic components of earlywood and latewood derived in this study extended the moisture-dependent mechanical model of wood, offering theoretical guidance for the practical application of Chinese fir and other wood species.

Reducing manual labeling requirements and improved retinal ganglion cell identification in 3D AO-OCT volumes using semi-supervised learning.

Adaptive optics-optical coherence tomography (AO-OCT) allows for the three-dimensional visualization of retinal ganglion cells (RGCs) in the living human eye. Quantitative analyses of RGCs have significant potential for improving the diagnosis and monitoring of diseases such as glaucoma. Recent advances in machine learning (ML) have made possible the automatic identification and analysis of RGCs within the complex three-dimensional retinal volumes obtained with such imaging. However, the current state-of-the-art ML approach relies on fully supervised training, which demands large amounts of training labels. Each volume requires many hours of expert manual annotation. Here, two semi-supervised training schemes are introduced, (i) cross-consistency training and (ii) cross pseudo supervision that utilize unlabeled AO-OCT volumes together with a minimal set of labels, vastly reducing the labeling demands. Moreover, these methods outperformed their fully supervised counterpart and achieved accuracy comparable to that of human experts.

Three-Dimensional Visualization Of The Behavior Of Solid Particles Traveling In A Horizontal Gas Pipe Flow By Color PTV Using Discontinuously Changing Hue Illumination

In a gas pipe, a lot of solid particles remained during its construction. They are called dust and gas supply companies have tried to remove them using filters because they cause various problems. To optimize the maintenance period of dust removal filters, it is required to understand the behaviors of particles in the pipe. However, we do not fully understand yet because of their very complex behaviors caused by dune accumulated in the pipe. Furthermore, it is hard to investigate their behaviors with a traditional volumetric PTV using multiple cameras. Normally, its calibration is difficult because of the curvature of the pipe and the plural number of cameras. Therefore, we developed a new volumetric color PTV algorithm with discontinuously changing color illumination in the camera shooting direction, i.e. the depth direction. Color PTV can determine particle positions in three dimensions using a single camera but has low depth accuracy. Our new PTV measures particle positions and velocity vectors in the plane of picture using the same algorithm used in the normal planar PTV. On the other hand, particle positions and velocity vectors in the camera shooting direction are measured by a pattern of color changing on particle scattering light, which is our original method. To adopt the new volumetric PTV in the pipe flow, a volumetric light changing color discontinuously in the flow direction was irradiated and the particles were visualized using a camera installed at the outlet of the pipe. When a dune exists, the particles are thrown to the top of the pipe and their advection velocity is increased by the wakes generated by the dune. As a result, the dune makes more particles to be advected to a longer distance.

THE COMBAT ENGAGEMENT (COMBAT EPISODE) LIFE CYCLE INTERACTIVE THREE-DIMENSIONAL VISUALIZATION CRITERIA AND INDICATORS SELECTION

The russo-Ukrainian war is generally characterized as an artillery war, since the main burden in it is the massive use of artillery. However, this war is distinguished from others by the use of various tactics, some of that repeat the tactics of the past, only at a higher technical level, and the newest tactics that have appeared thanks to the advent of modern weapons and military equipment, the which principles are based on the latest technical achievements. The specified circumstances require a careful and more detailed consideration (research) of these tactical techniques on such issues as the reasons for their occurrence, the number of participants, the course of the battle (combat episode), its result, analysis and development, practical recommendations that can be combined into a single concept of the life cycle, eliminate identified shortcomings or provide recommendations for improving individual positions in this matter. For this purpose, it is advisable to reproduce and reconstruct the life cycle of the combat engagement or combat episode that occurred. One of the means of reproducing the life cycle of a combat engagement (combat episode) is interactive three-dimensional visualization. Therefore, in order to create an interactive three-dimensional visualization model (animation) of the life cycle of a combat engagement or a combat episode, that would correspond as close as possible to real events, it is desirable to determine the criteria and indicators that characterize these events. The interactive three-dimensional visualization of the life cycle of a combat engagement or combat episode criterion can be the completeness and reliability of information, and the indicators - dynamism, evaluation of the effectiveness of combat operations and characteristics of the space (locality) in which the combat engagement (combat episode) took place.