Three-dimensional Scanning Research Articles

Assessing the Influence of Hyaluronan Dressing on Wound Healing on Split-Thickness Skin Graft Donor Sites Using a Three-Dimensional Scanner

Objectives: The topical application of hyaluronic acid after injury may accelerate the wound healing process. We aimed to retrospectively investigate whether the topical application of hyaluronic acid on standardized wounds after split-thickness skin graft removal on the thigh would accelerate wound healing and improve scarring outcomes. Additionally, we aimed to evaluate the usefulness of three-dimensional (3D) scanning to assess scars. Methods: The wound healing process of a hyaluronan group (n = 20) and a control (n = 21) were analyzed and evaluated using 3D scans at 7 and 14 days and 1, 3, and 6 months post-operatively. Scar evaluations by the patients were conducted 6 months post-operatively using the patient and observer scar assessment scale and the Manchester scar scale. Experts evaluated the scars after 6 months using a modified version of both scales. Results: On days 7 and 14, significantly larger areas of the wound surface were closed in the hyaluronan group compared to the control group (p < 0.05). After 1 month, significantly more crusted areas remained in the control group than in the hyaluronan group (p < 0.05). At the 6-month self-assessments, the hyaluronan group evaluated their scars as being significantly better compared to the control group. Conclusions: The topical application of hyaluronic acid in combination with polyurethane foam as a wound dressing after split skin removal accelerated the wound healing rate and positively influenced scar appearance after 6 months. Three-dimensional scanning is useful for evaluating and documenting the wound healing process.

Study on the evolution rules of coal deformation and failure characteristics caused by multiple mining disturbances

During coal mining operations, the coal will be deformed and damaged due to multiple mining disturbances (MMD), often resulting in disasters, like rock burst. To understand the evolution rules of coal deformation under MMD and its final fracture characteristics after impact dynamic load loading, reduce the adverse effects of mining disturbances, and improve disaster prevention and control capabilities, quasi-static uniaxial cyclic loading-unloading (L-U) and dynamic axial compression tests were conducted on large-sized coal-like samples. During the tests, three-dimensional (3D) laser scanning and acoustic emission (AE) monitoring technology were utilized to accurately capture the full-field deformation and AE response data, facilitating a systematic analysis of deformation and fracture characteristics. The results show that: (1) Under the cyclic L-U effect induced by MMD, each loading cycle causes compression deformation with partial recovery during unloading, presenting an overall “wavy” variation trend. (2) The maximum load is the most critical factor affecting the damaged coal deformation, with smaller load resulting in less overall sample deformation. (3) After the impact dynamic loading, the damaged samples suffered large-scale impact splitting failure, with the compressive-shear layer failure mainly occurred inside the holes. (4) Lower loading during cyclic L-U process correlate with reduced damage degree, and smaller debris particles with a higher fractal dimension when impact failure occurs, indicating a more severe impact failure. (5) With multiple cycles of L-U, the cracks inside the sample gradually extend and expand from around the hole to the outside. The greater the load and the number of cycles, the more serious the crack damage will be. (6) In the practical mining process, it is crucial to reinforce roadway interiors while minimizing low-loading cyclic disturbances induced by MMD. The study has obtained the deformation evolution rules and failure characteristics of coal under MMD, providing a theoretical basis for the prevention and control of corresponding engineering disasters.

Diagnostic and treatment possibilities in the management of positional plagiocephaly.

Positional plagiocephaly, characterized by an asymmetric skull shape, is the most common craniofacial malformation in infancy. Associated risk factors include apreference for the supine position, first and assisted delivery, multiple pregnancy, prematurity, and congenital muscular torticollis. The diagnosis is established by clinical and anthropometric examinations. In the case of moderate or severe deformity, three-dimensional optical scanning enables adetailed depiction of the deformity and provides asafe and noninvasive tool for follow-up. Treatment mainly includes repositioning of the infant, while orthotic therapy is considered in cases of severe deformity. Cranial orthotic therapy is most effective when started between 4and 7months of age. The total duration of orthotic treatment ranges from 2to 6months. Although the clinical course of positional plagiocephaly is generally benign and the prognosis favorable, its increasing prevalence has prompted the development of novel diagnostic and therapeutic strategies over the past decade.

Synchronous (In)significance: Recording Ukraine’s Cultural Heritage in Real-Time

ABSTRACT Synchronous (In)significance argues for the recognition of a mode of heritage conservation within war-torn Ukraine that is already underway. The paper examines the digital initiative Polycam: Backup Ukraine which allows for everyday users to record, upload and share three-dimensional scans of places, sites and objects that they deem significant within their immediate environment. This evolving contemporary archive is positioned by its founders as a tool for citizen empowerment through the shared availability of the technology and storage of items for heritage capture. The resulting collection provides an unconventional account of the sites, spaces and objects at risk in Ukraine, creating a constellation of high, local, formal and idiosyncratic personal entries. Through this portal, a broad and unsanctioned account of Ukrainian heritage is revealed. This paper draws on the work of Tracy Ireland, Steve Brown and John Schofield which examines the dichotomous relationship of significance and insignificance in the practice of value creation and negotiation of heritage identity. Through this lens it examines how notions of sharing; shared technology, shared ownership and shared access might allow for the creation of a contemporary heritage archive, that interacts with memory, place and things, but does so in ways that “are often not possible in the context of official heritage regimes because of rigid aesthetic paradigms, urban or class conflict, identity politics, or dominant national narratives.” 1 The archive, which draws together digital records of well-regarded heritage sites with unexpected spaces and objects of the personal and the everyday, becomes a means of assessing notions of significance and (in)significance in real-time. This in turn, provides a mechanism for re-evaluating what aspects of the war-torn country are considered worthy of recording and sharing.

Extraction of deterioration and analysis of vegetation impact effects on the south palace wall of Weiyang Palace

Weiyang Palace, the royal palace of the Western Han Dynasty, is a part of the Silk Roads: the Routes Network of Chang’an-Tianshan Corridor on the World Heritage list. The south palace wall of Weiyang Palace is a well-preserved earthen heritage site within the palace, but it is undergoing continuous deterioration due to the influence of vegetation and external environmental factors. This study pioneers the integration of high-resolution three-dimensional LiDAR scanning with multi-source data analysis, including unprecedented on-site botanical surveys, to explore the subtle effects of different vegetation types on the structural integrity of the south palace wall. Through contour line analysis and facade grid analysis, we extracted the deterioration locations of typical sections of the earthen heritage sites. And we classified the overlying vegetation types on the wall using an object-oriented classification algorithm. Our findings reveal a complex interaction between vegetation and earthen structures: paper mulberry exhibits protective qualities against erosion, while Ziziphus jujuba significantly exacerbates structural vulnerabilities. The methodologies applied in this study for extracting deterioration at earthen heritage sites and integrating multi-source spatial data can serve as a technical application model for monitoring and analyzing the driving forces of earthen heritage sites along the entire Silk Road network, thereby better guiding the conservation of earthen heritage sites.

A multicenter bladder cancer MRI dataset and baseline evaluation of federated learning in clinical application

Bladder cancer (BCa), as the most common malignant tumor of the urinary system, has received significant attention in research on the clinical application of artificial intelligence algorithms. Nevertheless, it has been observed that certain investigations use data from various medical facilities to train models for BCa, which may pose a privacy risk. Given this concern, protecting patient privacy during machine learning algorithm training is a crucial aspect that requires substantial attention. One emerging machine learning paradigm that addresses this concern is federated learning (FL). FL enables multiple entities to collaboratively build machine learning models while preserving data privacy and security. In this study, we present a multicenter BCa magnetic resonance imaging (MRI) dataset. The dataset comprises 275 three-dimensional bladder T2-weighted MRI scans collected from four medical centers, and each scan includes diagnostic pathological labels for muscle invasion and pixel-level annotations of tumor contours. Four FL methods are used to assess the baseline of the dataset for both the task of diagnosing muscle-invasive bladder cancer and automatic bladder tumor lesion segmentation.

The MapMe Body Scales: Validity and Reliability of a Biometrically Accurate, Photorealistic Set of Child Body Size Scales.

It is vital to identify children whose weight status means that they may benefit from medical or behavioural support, but adult visual judgements of child weight status are inaccurate, and children are seldom routinely weighed and measured. Consequently, there is a need for validated visual tools for use in training, communication, and interventions relating to child weight. This paper presents validation data for a set of innovative photo-realistic colour body size scales depicting boys and girls aged 4-5 and 10-11. Each age- and gender-specific scale consists of 7 figures based on three-dimensional (3D) scans of 388 children to accurately represent the change in body size caused by changing adiposity. To assess scale validity, 238 adult participants (105 men, 132 women, 1 non-binary individual) undertook two tasks: rating figure adiposity using a visual analogue scale and ranking figures in ascending order of adiposity (OSF Reference: gdp9j). Participants accurately estimated the relative adiposity of each figure, i.e., they were able to tell the difference between figures and correctly rank them by size. This demonstrates scale validity for use in body size tasks. One hundred and fifty-one participants also provided 3-day test-retest data, which demonstrates excellent short-term reliability. Overall, the MapMe child body size scales provide an anthropometrically accurate, valid, reliable, and usable tool for size-related tasks and communication with adults regarding child weight.

3dct Conduit and Oesophageal Metrics, a Valuable Method to Diagnose Post Sleeve Gastrectomy Abnormalities.

Reflux after laparoscopic sleeve gastrectomy (LSG) may result from anatomical and functional anomalies in the gastric conduit. Three-dimensional CT scans (3DCT) offer a comprehensive view of gastric anatomy. This study aims to establish specific measurements associated with sleeve abnormalities to standardise the reporting of 3DCT which may help in management of LSG complications. This retrospective study analysed 64 post-LSG patients who underwent gastric 3DCT. Data included clinical demographics, pre-LSG BMI, BMI at 3DCT, and the duration between surgery and examination. Symptomatology prompts the scan and other concurrent investigations. Various 3DCT measurements were taken, including angularis angle (AA), surface area (ASA), conduit length (CL), proximal maximal surface area (PMSA), and distal maximal surface area (DMSA) of the gastric conduit. Patients were categorised based on endoscopy findings and symptomatology. Outcomes post-revisional surgery were assessed and analysed. 20.3% were male. Pre-LSG BMI and BMI at 3DCT were 45.57 (± 8.3) and 36.3 (± 8.7), respectively. Mean surgery-to-scan period was 6.2years. 71.8% of patients presented with reflux, regurgitation, or dysphagia, whilst the remainder primarily exhibited weight regain. Patients with endoscopic evidence of stenosis/reflux demonstrated significantly lower gastric volume, ASA, and DMSA (p = 0.002 and p = 0.007, respectively). Oesophageal diameter above the conduit and an ASA to DMSA ratio ≤ 0.5 were negatively associated with AA (p = 0.008 and p = 0.08, respectively). Patients with improved outcomes after revisional bypass and gastrogastrostomy displayed a negative correlation with ASA and positive correlation with the ASA to PMSA ratio (≤ 0.5). 3DCT measurements have a potential role in defining post-LSG stenosis and predicting outcomes of revisional surgery. Patients with anatomic abnormalities that are shown on CT appear to improve with anatomic correction.

Therapeutic Effectiveness of a Novel Cranial Remolding Helmet (baby band2) for Positional Plagiocephaly: A Multicenter Clinical Observational Study.

This multicenter study evaluated the efficacy and safety of a novel cranial remolding helmet (baby band2), which is completely custom-made based on the shape of an infant's cranium. The study included 224 full-term infants from moderate to very severe positional plagiocephaly in Japan. Cranial geometry was assessed before and after helmet therapy using a three-dimensional scanner, and changes in the cranial vault asymmetry index (CVAI) were analyzed. The CVAI improved significantly in all patients, with the most significant improvement observed in the most severely affected group [very severe group: -9.1, severe group: -6.6, moderate group: -4.4 (mean values), p < 0.001]. The group that started therapy before the age of 7 months showed greater improvement compared to those who started therapy at the age of 7 months or older; however, both groups demonstrated significant improvement (<7 months group: -6.6, ≥7 months group: -4.4 (mean values), p < 0.001). No significant differences were observed in therapy efficacy between the centers (p = 0.402) and sex (p = 0.131). During the study period, helmet therapy did not lead to head circumference stunting, and the incidence of redness with baby band2 was five patients (2.2%). This study demonstrated that baby band2 is effective and safe for the therapy of positional plagiocephaly.

Contribution of spatially variable pitting corrosion on fatigue life prediction of RC beams

Pitting corrosion induces stress concentration in steel bars, significantly reducing the fatigue life of reinforced concrete (RC) beams. Moreover, spatially variable pitting corrosion can cause fatigue fractures in tensile steel bars at various cross-sections of beams, not just at the mid-span section. This will further increase the failure probability of beams but is rarely considered by existing studies. Thus, this study proposes a fatigue life prediction method for RC beams experiencing spatially variable pitting corrosion. First of all, the spatial variability of pitting corrosion in tensile steel bars in RC beams is simulated through the three-dimensional laser scanning method and the spectral representation method, in which the steel bar diameter, length, distance, corrosion level, and the correlation between corrosion pits are systematically considered. Subsequently, the fatigue crack initiation and propagation of pitting corroded steel bars are modeled based on fracture mechanics. The spatial analysis is then conducted on corroded RC beams until fatigue failure occurs. The proposed prediction method is verified with results from existing references. The findings highlight that neglecting the spatial variability of pitting corrosion leads to an overestimation of the fatigue life of corroded RC beams, especially under uniformly distributed loadings and high corrosion levels. This study provides a reasonable prediction for the lifespan of corroded RC beams.

MIXED PATHOPHYSIOLOGIES OF LAMELLAR MACULAR HOLES AND RELATED DISEASES: A Multimodal Optical Coherence Tomography-Based Study.

To investigate the characteristics of mixed pathophysiologies in lamellar macular holes (LMHs) and related diseases using multimodal optical coherence tomography. Overall, 126 eyes diagnosed with LMH, epiretinal membrane foveoschisis, or macular pseudohole using the horizontal B-scan image according to the definition proposed by Hubschman et al in 2020 were analyzed using multimodal optical coherence tomography imaging including horizontal and vertical 5-line B-scan, radial scan, and macular three-dimensional volume scan images. If at least two diagnostic criteria for LMH, epiretinal membrane foveoschisis, or macular pseudohole were satisfied in these scans, the patient was diagnosed as having a "mixed type." Retinal traction force was quantitatively evaluated by measuring the maximum depth of the retinal folds using en-face images. Mixed types constituted 34.1% of the cases. The LMH-related mixed group demonstrated intermediate characteristics between the epiretinal membrane foveoschisis/macular pseudohole and true LMH groups in terms of retinal traction and LMH-specific features and had a significant positive correlation between the maximum depth of the retinal folds and mean M-CHARTS scores (P = 0.034). A thorough optical coherence tomography analysis is necessary to accurately diagnose LMH and related diseases. A significant positive correlation was observed between the maximum depth of the retinal folds and the degree of metamorphopsia in the LMH-related mixed group.

Gaze tracking embedded collaborative robots for automated metrology and reverse engineering

Conventional geometric metrology, or three-dimensional (3D) scanning, and reverse engineering heavily rely on the experience of the operators. With an increasing need for automation, robot arms have been adopted for this task. However, due to the large variety of parts and designs, automated path planning could provide a scanning solution that may overlook the critical area, which could potentially deteriorate the scan results. This article explores the integration of collaborative robotics (cobots) with eye-tracking technology to improve the autonomous 3D scanning process. The primary objective of this study is to enhance the accuracy and efficiency of cobots in 3D scanning, particularly in the capture of functionally critical areas, and to provide a detailed description of regions with complex geometric features. The study develops a framework where the scanning path of the robot-driven scanner is partially guided by eye tracking data, that is, calibrated gaze tracking, to improve the automated 3D scanning process. This framework provides an innovative integration of human gaze movement with automatic robot path planning, providing a new way of human-autonomy teaming. Case studies are presented to present and validate the proposed framework to automatically improve the 3D point cloud collection process, specifically in areas that usually require human manual intervention to capture details.

Tunnel full-space deformation measurement based on improved downsampling and registration approach by point clouds

To fully leverage the volume measurement advantage of three-dimensional laser scanning technology in tunnel deformation monitoring, a full-space deformation analysis is proposed. A Box Improved Moving Average (BIMA) method featured by the adaptive window size downsampling is proposed which aims to achieve varying levels of downsampling in different densities regions. the combination of Maximal Cliques (MAC) and Iterative Closest Point (ICP) is utilized to achieve accurate registration. Point normal information is utilized to determine the correspondence to calculate deformation which shows an average accuracy of 7 % higher than the ICP by a convergence measurement test. The deformation convergence accuracy can go beyond 76 % when the point cloud reserved rate is approximately 10 %. Comparison between the method proposed in this study and the traditional point cloud cross sectional fitting method shows that the discrepancy between these two methods is approximately within 5 mm, with a minimum value of only 0.15 mm.

Laboratory investigation on fracture initiation and propagation behaviors of hot dry rock by radial borehole fracturing

Creating complex and interconnected fracture networks between injection and production wells is crucial for exploiting hot dry rock (HDR) geothermal energy. However, the simple planar fractures created by conventional hydraulic fracturing, primarily controlled by in situ stress, fail to connect directionally with the target well. This study proposes a novel stimulation method, i.e. radial borehole fracturing, which shows great potential for guiding the directional propagation of fractures. The fracture initiation and propagation behaviors of high-temperature granite under radial borehole fracturing are investigated and compared with those of conventional fracturing. Three-dimensional morphological scanning and reinjection tests are used to quantitatively evaluate fracturing performance. Additionally, the influences of key parameters, including rock temperature, in situ stress, injection rate, fluid viscosity, azimuth of the radial borehole, and the number of radial boreholes on the fracture morphology and breakdown pressure are investigated. The results show that radial borehole fracturing can effectively guide the initiation and propagation of fractures along the radial borehole. The breakdown pressure of radial borehole fracturing can be reduced by 14.1%-43.7% compared to conventional fracturing. A higher fluid-rock temperature difference reduces the directional propagation range of fractures guided by the radial borehole. Increases in the vertical density of radial boreholes, injection rate, and fluid viscosity enhance the guiding ability of radial boreholes. Furthermore, there is a competitive relationship between in situ stress and the azimuth of radial boreholes in controlling fracture propagation. This research provides a viable alternative for the directional connection of injection-production wells in HDR reservoirs.

Accurate prediction of disease-risk factors from volumetric medical scans by a deep vision model pre-trained with 2D scans.

The application of machine learning to tasks involving volumetric biomedical imaging is constrained by the limited availability of annotated datasets of three-dimensional (3D) scans for model training. Here we report a deep-learning model pre-trained on 2D scans (for which annotated data are relatively abundant) that accurately predicts disease-risk factors from 3D medical-scan modalities. The model, which we named SLIViT (for 'slice integration by vision transformer'), preprocesses a given volumetric scan into 2D images, extracts their feature map and integrates it into a single prediction. We evaluated the model in eight different learning tasks, including classification and regression for six datasets involving four volumetric imaging modalities (computed tomography, magnetic resonance imaging, optical coherence tomography and ultrasound). SLIViT consistently outperformed domain-specific state-of-the-art models and was typically as accurate as clinical specialists who had spent considerable time manually annotating the analysed scans. Automating diagnosis tasks involving volumetric scans may save valuable clinician hours, reduce data acquisition costs and duration, and help expedite medical research and clinical applications.

Three-dimensional Analysis of Lifting Effects after High-intensity Focused Ultrasound (Ultraformer-MPT) across Seven Facial Aesthetic Units Considering SonoAnatomy.

This investigation delves deep into the lifting degree for each area of noninvasive facial rejuvenation through high-intensity focused ultrasound (HIFU). The study meticulously examines the lifting effects of HIFU treatment across seven distinct facial aesthetic-units, using advanced three-dimensional scanner analysis. The study examined a cohort of 50 patients treated with HIFU. Pre- and immediate posttreatment evaluations were conducted using three-dimensional scanner analysis, allowing for precise quantification of lifting effects across seven aesthetic units. Treatment protocols were tailored to leverage five cartridges with micropulsed mode options, optimizing outcomes based on sonographic anatomy. The forehead was lifted by 1.24 mm; crow's feet, 2.25; malar region, 2.46; posterior cheek, 3.40; jowl, 2.90; mandible, 3.09; and neck, 3.53. The forehead showed a lift of 1.24 mm, attributed to the thin tissue requiring a cautious approach to avoid discomfort. A lift of 2.25 mm in the crow's feet area demonstrated the efficacy of HIFU in addressing fine lines and wrinkles. Significant lift of 2.47 mm in the malar region highlights HIFU's effectiveness in addressing mid-face laxity and restoring volume to the cheeks. The most substantial lift of 3.38 mm in the posterior cheek underscores targeted energy application for enhanced lifting and contouring. Notable lifting effect of 2.90 mm in the jowl area benefits sagging along the jawline, refining facial contour. Lift of 3.10 mm in the mandible shows improvement of lower facial laxity, defining the jawline. The highest lift of 3.55 mm in the neck region addresses laxity and sagging for a defined neck profile.

Effect of crack depth on the initiation and propagation of crack-induced sliding in a paleosol area on a loess slope: Three-dimensional investigation based on model testing and laser scanning

On the Chinese Loess Plateau (CLP), crack-induced sliding in paleosols triggers retrogressive slope collapse, compromising the long-term stability of loess slopes. Establishing a quantitative relationship between crack depth and slide size is key to elucidating the progressive evolution of crack-induced sliding in paleosols; however, research on this topic is scarce. In this study, a model test was conducted on a paleosol slope subjected to five drying–rainfall cycles. Three-dimensional (3D) laser scanning technology was employed to accurately quantify the variations in crack depth and slide size, and water content sensors were embedded to monitor the preferential flow changes induced by these cracks. Results reveal that crack depth plays a pivotal role in initiating and controlling the propagation of crack-induced sliding in paleosols by influencing the preferential flow capacity through cracks. In the slide initiation stage, a critical crack depth capable of triggering sliding by inducing a sufficiently significant preferential flow and large saturation zones was identified. The depth at which sliding occurs can be expressed as a variable dependent on crack depth based on the single triggering effect of cracking on sliding. Once a crack-induced slide is initiated, the combined action of prior sliding events and current crack propagation accelerates the subsequent sliding in terms of increased size and varying spatial locations by influencing the preferential flow capacity and sliding force values. A comprehensive empirical formula was established to characterize the depth of crack-induced slides, considering the dominant influence of crack depth and slope gradient on sliding development at this stage of slide evolution. Our findings emphasize the pivotal role of crack depth in triggering progressive crack-induced sliding in paleosols, thereby providing valuable insights for soil conservation in paleosol areas on loess slopes on the CLP.

The effects of shoulder morphology on the distribution of shoulder pressure during load carriage.

To enhance the prevention of shoulder pressure injuries in various load-bearing populations, the effects of shoulder morphology on pressure distribution were investigated. In this study, 69 participants underwent three-dimensional scanning, and based on shoulder morphological characteristic indicators, they were classified into four shoulder types. From these, 28 participants were selected to have the pressure within shoulder regions measured using a pressure-sensing vest while carrying a backpack load equivalent to 15% of their body weight. The results indicated that variations in shoulder morphology significantly impact pressure distribution. The greater bumpiness of the shoulder surface contributed to pressure concentration at specific points, resulting in uneven pressure distribution. The enhanced fullness of the shoulder surface promoted even pressure dispersal across the area. This study provided a theoretical basis for developing more effective shoulder injury prevention and management strategies tailored to load-bearing populations with different shoulder types.

Influence of Head Circumference on the Accuracy of Facial Scanning: An In vitro Study

ObjectivesThis study aimed to investigate the impact of head circumference on the accuracy of three-dimensional (3D) facial scans, focusing on trueness and precision across three mannequin heads of different sizes. Material and methodsThree 3D-printed mannequin heads with circumferences of 30, 50, and 65 cm were used. Ten facial landmarks were identified to measure seven interlandmark distances and two angles. Direct anthropometric measurement, serving as the reference value, was taken using a digital vernier calliper for linear distance, and angle was calculated using the law of cosines. Each head was scanned six times using two systems: a dual-structured light facial scanner (iTom) and a stereophotogrammetry system (3dMD). Digital measurements were analysed using Meshlab and Blender for distances and angles, respectively. Trueness values were determined by comparing measurements to reference measurements, while precision values were derived from the variability among the six scans. Statistical analysis was performed using the Kruskal–Wallis test due to nonhomogeneous variances, followed by Bonferroni correction for pairwise group comparisons. ResultsFor each scanning system, overall deviations in trueness and precision significantly increased with head circumference. Five of the seven distances and one angle showed significant compromises in trueness with larger head circumferences. Most measurements exhibited significant precision decreasing due to head circumference changes, except for N-Pn and Pn-Sn. Additionally, 3dMD displayed higher overall trueness compared to iTom, with five out of seven linear measurements and one angular measurement showing better results. ConclusionHead circumference significantly affects both trueness and precision of 3D facial scans for both technologies, suggesting that facial imaging should be used with caution for larger faces. Selecting an appropriate scanning system, such as 3dMD, can help mitigate the negative effects of scanning larger objects.

Point cloud data-driven modelling of high-strength steel wire corrosion pits considering orientation features

We propose a corrosion pit modelling approach of high-strength steel wires considering orientation features using surface point cloud data, collected by three-dimensional laser scanning. Corrosion pits were identified through density-based spatial clustering of applications with noise (DBSCAN). The identified corrosion pits could be modelled as a semiellipsoid considering orientation features. The Gaussian copula model was utilised to describe the joint distribution of the geometric parameters of the corrosion pits. This approach will be valuable for simulation of the surface morphology of corroded high-strength steel wires.