Towards Intelligent Monitoring System in Wire Arc Additive Manufacturing: A Surface Anomaly Detector on a Small Dataset

Rapid developments in artificial intelligence and image processing have presented many new opportunities for defect detection in manufacturing processes. In this work, an intelligent image processing system has been developed to monitor inter-layer deposition quality during a Wire Arc Additive Manufacturing (WAAM) process. Information produced from this system is to be used in conjunction with other quality monitoring systems to verify the quality of fabricated components. It is tailored to identify the presence of defects relating to lack-of-fusion and voids immediately after the deposition of a given layer. The image processing system is built upon the YOLOv3 architecture and through moderate changes on anchor settings, achieves 53% precision on surface anomaly detection and 100% accuracy in identifying the fabricated components’ location, providing a prerequisite for high precision assessment of welding quality. The work presented in this paper presents an inter-layer vision-based defect monitoring system in WAAM and serves to highlight the feasibility of developing such intelligent computer vision systems for monitoring the WAAM process for defects.

Accuracy Tests and Precision Assessment of Localizing Underground Utilities Using GPR Detection

Applying georadar (GPR) technology for detecting underground utilities is an important element of the comprehensive assessment of the location and ground infrastructure status. These works are usually connected with the conducted investment processes or serialised inventory of underground fittings. The detection of infrastructure is also crucial in implementing the BIM technology, 3D cadastre, and planned network modernization works. GPR detection accuracy depends on the type of equipment used, the selected detection method, and external factors. The multitude of techniques used for localizing underground utilities and constantly growing accuracy demands resulting from the fact that it is often necessary to detect infrastructure under challenging conditions of dense urban development leads to the need to improve the existing technologies. The factor that motivated us to start research on assessing the precision and accuracy of ground penetrating radar detection was the need to ensure the appropriate accuracy, precision, and reliability of detecting underground utilities versus different methods and analyses. The results of the multi-variant GPR were subjected to statistical testing. Various analyses were also conducted, depending on the detection method and on the current soil parameters using a unique sensor probe. When planning detection routes, we took into account regular, established grids and tracked the trajectory of movement of the equipment using GNSS receivers (internal and external ones). Moreover, a specialist probe was used to evaluate the potential influence of the changing soil conditions on the obtained detection results. Our tests were conducted in a developed area for ten months. The results confirmed a strong correlation between the obtained accuracy and the measurement method used, while the correlation with the other factors discussed here was significantly weaker.

3D-printing for the precision assessment of a new medical device

Additive manufacturing played a keyrole in investigating the precision of a recently-developed device that measures the elastic characteristics of the trabecular bone by simulating the application of loads on a virtual biopsy obtained from radiographic images of the proximal epiphyses in the patient’s hand fingers. The simulation results are combined in a Bone Structure Index (BSI), which has shown to be able to detect trabecular bone alterations due to osteoporosis or other pathological situations. In order to obtain a large number of measurements without having voluntary patients undergo unnecessary radiations, the precision assessment tests were carried out on a 3D-printed phantom hand, in which different mimicked trabecular structures (chips) were inserted. Each mimicked bone had a unique internal structure and density and was 3D-printed using radiopaque composite materials. Fifteen different chips were additively manufactured; 20 measurements were performed on each chip. BSI and BSI_T-score precision values were computed according to ISO 5725 and ISCD standards. For all the chips, no relationship was found between the mean [Formula: see text] and standard deviation [Formula: see text] of the measurements in each chip. The range of the 95% confidence interval ([Formula: see text]) was computed assuming the repeatability standard deviation [Formula: see text] as the known standard deviation of the measurement method (average of [Formula: see text] values): [Formula: see text], corresponding to [Formula: see text]. Least Significant Change was evaluated as well: [Formula: see text], corresponding to [Formula: see text]. The 95% confidence intervals are small when compared to the commonly-accepted diagnostic values, where a patient is classified as osteoporotic if T-score < −2.5, non-osteoporotic if T-score > -1 and osteopoenic if -2.5 < T-score < -1. The LSC results are in line with the requirements for the gold-standard osteoporosis diagnostic systems. Additive manufacturing made it possible to avoid irradiation of humans in this precision assessment.

PRECISION ASSESSMENT OF THE STATE OF BONE TRABECULAE AND MINERAL SATURATION OF BONE SPONGY STRUCTURES IN WORKERS EXPOSED TO CONTACT ULTRASOUND

A comparative retrospective analysis of the results of a clinical - X-ray examination of 93 women doctors of ultrasound examinations of working age and 60 people was performed. control groups of age and experience comparable work with persons of major groups (nurses not associated with exposure to occupational ultrasound). Degenerative-dystrophic changes were revealed in the form of: osteorthrosis of the shoulder, elbow, wrist and interphalangeal joints, periarthrosis of the shoulder and elbow joints, small cyst-like clearances and enostoses in the bones of the wrists of the most loaded upper limb. The level of decrease in the mineral saturation and thickness of bone trabeculae in the areas of interest of the radius bones and distal phalanges of the hands was dependent on the severity of the clinical picture of vegetative-sensory polyneuropathy. Indicators of bone density and the state of bone trabeculae in the spongy structures of the distal radial bones and distal phalanges can be a kind of marker of the severity of OP. The use of modern methods for assessing the density and structure of bone tissue allows us to reduce the negative role of the so-called "human factor" and thus

Non-Binary Snow Index for Multi-Component Surfaces

A Non-Binary Snow Index for Multi-Component Surfaces (NBSI-MS) is proposed to map snow/ice cover. The NBSI-MS is based on the spectral characteristics of different Land Cover Types (LCTs), such as snow, water, vegetation, bare land, impervious, and shadow surfaces. This index can increase the separability between NBSI-MS values corresponding to snow from other LCTs and accurately delineate the snow/ice cover in non-binary maps. To test the robustness of the NBSI-MS, regions in Greenland and France–Italy where snow interacts with highly diversified geographical ecosystems were examined. Data recorded by Landsat 5 TM, Landsat 8 OLI, and Sentinel-2A MSI satellites were used. The NBSI-MS performance was also compared against the well-known Normalized Difference Snow Index (NDSI), NDSII-1, S3, and Snow Water Index (SWI) methods and evaluated based on Ground Reference Test Pixels (GRTPs) over non-binarized results. The results show that the NBSI-MS achieved an overall accuracy (OA) ranging from 0.99 to 1 with kappa coefficient values in the same range as the OA. The precision assessment confirmed the performance superiority of the proposed NBSI-MS method for removing water and shadow surfaces over the compared relevant indices.

Airborne LiDAR-Derived Digital Elevation Model for Archaeology

The use of topographic airborne LiDAR data has become an essential part of archaeological prospection, and the need for an archaeology-specific data processing workflow is well known. It is therefore surprising that little attention has been paid to the key element of processing: an archaeology-specific DEM. Accordingly, the aim of this paper is to describe an archaeology-specific DEM in detail, provide a tool for its automatic precision assessment, and determine the appropriate grid resolution. We define an archaeology-specific DEM as a subtype of DEM, which is interpolated from ground points, buildings, and four morphological types of archaeological features. We introduce a confidence map (QGIS plug-in) that assigns a confidence level to each grid cell. This is primarily used to attach a confidence level to each archaeological feature, which is useful for detecting data bias in archaeological interpretation. Confidence mapping is also an effective tool for identifying the optimal grid resolution for specific datasets. Beyond archaeological applications, the confidence map provides clear criteria for segmentation, which is one of the unsolved problems of DEM interpolation. All of these are important steps towards the general methodological maturity of airborne LiDAR in archaeology, which is our ultimate goal.

Precision X-ray diagnosis of osteoporosis in representatives of risk groups for the appearance and development of varicose disease of the lower limbs

Introduction. Varicose disease of the lower limbs (VDLL) is an independent disease and is an important medical and social problem due to its widespread and tendency to progress among people of working age and mainly in the female half of the population. Features of professional activity are risks in the form of static loads of a constant nature or weightlifting and other risk factors (for example, genetic predisposition, hormonal imbalance during pregnancy and menopause, obesity, diabetes mellitus, hypercoagulation, treatment with hormonal drugs, irrational nutrition, alcohol abuse, the presence of osteopenia and osteoporosis (OP). A feature of the disease is the presence of concomitant (often combined) pathology of the musculoskeletal system, which is characterized, as a rule, by early manifestation, relatively rapid progression, and complicated course. Radiologically, relatively often revealed pathology of the feet (flat feet, hallux valgus and deformity of the 1st finger) and degenerative-dystopian changes in the spine (osteochondrosis, spondyloarthritis, spondylosis, scoliosis, kyphosis). The most pronounced combined pathology of the musculoskeletal system is observed in patients with active trophic disorders. Considering the comorbidity of the disease, changes in regional hemodynamics and microcirculation in the lower limbs undoubtedly affect the indicators of hemostasis, carbohydrate, lipid and mineral metabolism. Therefore, a significant interest to improve the diagnosis of OP are often present in the form of a clinical syndrome, which is characterized by decrease in bone density, a violation of their micro-and increased fragility, due to the metabolic disorders of bone tissue with a predominance of catabolism over the processes of bone formation and increased risk of fractures. The state of bone mineral saturation, in particular in the female half of the population, depending on the severity of venous insufficiency remains insufficiently studied. Treatment of VDLL and its concomitant OP syndrome is not always a solvable problem, so the optimization of the diagnosis of this disease, especially at the initial stages, as well as in the process of dynamic monitoring and control of the effectiveness of therapeutic and preventive measures remains relevant. The aim of the study was to study the diagnostic possibilities of using radiometry (radiocomparametry and digital osteodensitometry) for precision assessment of mineral saturation of the spongy structure of the calcaneus in patients at risk for the appearance and development of VDLL. Materials and methods. As part of the general clinical examination, special comparative X-ray studies of the state of mineral saturation and dimensional characteristics of bone trabeculae of the spongy structure of the calcaneus were performed in 129 women with clinical signs of VDLL, which in accordance with the international classification of CEAP were divided into stages: C1 - 36 people, C2 - 32 people, C3 - 39 people, C4 - 30 people, C5 - 22 people. The comparison group included 119 practically healthy women, comparable to the main group by age, work experience and morbid history. The X-ray diagnostic complex included, in addition to convective (routine) radiography of various parts of the osteoarticular apparatus, performed only according to indications, the following methods: interactive radiography (digital low-dose radiography) of the foot with a calibrated wedge-a standard of density, a posteriori testometric X-ray parametry of bone trabeculae of spongy structures of the calcaneus. Modern equipment was used: digital X-ray diagnostic complexes DR-GEBrivo), AXIOMLuminas (Siemens), dichromatic osteodensitometer "PRODIGY" (Lunar). Results. As part of the general clinical examination, X-ray examinations were performed before the implementation of therapeutic measures and after 24 months. Radiometric indicators of mineral saturation and thickness of trabeculae of the spongy structure of the calcaneus showed a direct dependence on age, reaching maximum values in the age category of 25-30 years with a clear tendency to decrease in older age groups. The mineralization parameters relative to the control were initially reduced, revealing variability depending on the severity of the main pathological process (from relatively high at C1 to relatively low at C5). There was also a pattern of increasing levels of mineralization and thickness of bone trabeculae depending on the period of observation (in fact, on the volume of complex therapeutic and preventive measures) in almost all patients, but mainly in groups C4, C5. Subjective symptoms and objective clinical picture of the condition of the examined patients with the presence of VDLL and OP syndrome correlated with the data of osteorentgenometry. Conclusions. The examined women, whose production activity makes them belong to the risk group for the appearance and development of VDLL, have a opioid structure of the calcaneus. The use in complex clinical and radiological diagnostics of the methodical technique of precision assessment of mineral saturation in (mg/mm2) and thickness of bone trabeculae (mm) makes it possible to objectify the reconstruction of the bone structure at the submacroscopic level of its visualization. Quantitative densitometric indicators of changes in the spongy structure of the calcaneus can be considered as markers of the severity of the condition and the direction of the course of VDLL with concomitant OP. Postprocessing radiometry the calcaneus performed on digital radiographs and the screens of computers using programs "LINS MAKHAON workstation of the DOCTOR" available, not associated with additional radiation exposure and, therefore, can be widely applied both at the stage of primary diagnosis of the health status of the studied patients and in monitoring the effectiveness of remedial measures.