Comparison Of Contours Research Articles

Modern Kubernetes Ingress Solutions: an In-depth Comparison of Contour and Istio Architectures

This article presents a comprehensive comparative analysis of Kubernetes ingress controllers Contour and Istio, addressing the critical challenge of traffic management in modern cloud-native architectures. With Kubernetes adoption reaching 83% among enterprises in 2023, the selection of appropriate ingress controllers significantly impacts application performance, security, and operational efficiency. Through quantitative analysis of performance metrics across varying load conditions (100-10,000 RPS) and real-world case studies, this article evaluates both solutions across multiple dimensions. Results demonstrate that Contour exhibits superior performance in simple to medium-scale deployments with 30% better latency characteristics (0.5-1.5ms per request) and a 45% smaller memory footprint, while Istio proves more effective for complex deployments, handling up to 75,000 requests per second and reducing service-to-service communication latency by up to 60%. Implementation case studies of an e-commerce platform and a financial services system reveal that Contour achieves 99.99% availability with 47% infrastructure cost reduction, while Istio provides comprehensive security features including automated mTLS implementation and advanced observability tools. The article concludes with a detailed decision framework and implementation guidelines, enabling organizations to select and optimize the most appropriate ingress controller based on their specific requirements, scale of operations, and security needs. The findings demonstrate that while both solutions excel in their targeted use cases, the choice between them should be guided by application complexity, performance requirements, and operational constraints.

Enhancing performance of sandwich panel with three-dimensional orthogonal accordion cores

This study introduces a novel three-dimensional orthogonal accordion structure (3D-OAS) as the cellular core of sandwich panels, achieving multi-directional zero Poisson’s ratio through the orthogonal combination of two-dimensional accordion structures. To analyze its static characteristics effectively, a two-dimensional equivalent Reissner–Mindlin model (2D-ERM) was established utilizing the variational asymptotic method (VAM). The accuracy of 2D-ERM was confirmed by conducting three-point bending tests on 3D-printed specimens and analyzing the in-plane and out-of-plane deformation results of the 3D finite element model (3D-FEM). The comparison of global displacement contours and path-displacement curves between 3D-FEM and 2D-ERM showed a high level of agreement in predicting static deformation. The equivalent stiffness of SP-3D-OAS steadily increased as the inclined angle deviates by 90-degree, irrespective of whether it pertains to the convex or concave angle. Evaluation of deformability in sandwich panels with different cellular core forms revealed superior comprehensive performance in 3D-OAS, followed by 3D-YRS and 3D-XYAS, with a reduction of 16.41% and 17.35% in specific stiffness, respectively. Compared to the 3D-FEM, 2D-ERM significantly reduces computation time without compromising engineering accuracy. The research results provide a useful reference for optimal design of sandwich panels with multi-directional ZPR cellular core.

Comparison of proximal contact and contours of class II restoration in premolars and molars restored with three different matrix systems using FDI criteria: An in vivo study.

Sectional matrix systems, namely, Garrison and Bioclear with contact rings, are valuable aids to establish proximal contact tightness and contours in Class II composite restorations when compared with the circumferential matrix system Tofflemire. This study aimed to compare the proximal contact and contours of Class II restoration in premolars and molars restored with Tofflemire, Garrison, and Bioclear matrix system by FDI criteria of approximal anatomical form using floss or 25-µm metal blade and radiographic examination. Sixty Class II patients were selected, and a preoperative bitewing radiograph was taken. Initially, caries removal was done by round diamond bur, followed by 245 carbide bur. Samples were divided randomly into three groups based on the type of matrix system used for restoration. Group 1 (n = 20): Tofflemire, Group 2 (n = 20): Garrison matrix system, and Group 3 (n = 20): Bioclear matrix system. Matrix systems were applied according to the manufacturer's instructions, and composite restoration was done. The clinical evaluation of proximal contact and contour was done by a blinded observer immediately after placement of composite restoration using FDI criteria by passing dental floss or 25-µm metal blade, whereas marginal gaps and overhangs were checked using a radiograph. Results were statistically analyzed. The statistical analysis was done using the Statistical Package for the Social Sciences (SPSS for Windows, Version 19.0). Descriptive statistics was calculated as frequency and percentage. The comparison of characteristics of the contact points, contour, and radiographic examination was carried out using the Chi-square test. Multiple comparisons were done by comparing column proportions with Bonferroni adjustments. The level of significance for the present study was fixed at P < 0.05. There were significantly higher proportions of normal contacts in Garrison (60%) and Bioclear (70%) compared to that in the Tofflemire (20%) matrix system (Bioclear > Garrison > Tofflemire). Comparison of contours showed normal contours with Garrison (50%), Bioclear (50%), and Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). In radiographic examination, harmonious transitions between the restoration and the tooth were similar in Garrison (30%) and Bioclear (30%) compared to the Tofflemire (15%) matrix system (Bioclear = Garrison > Tofflemire). Garrison and Bioclear sectional matrix systems established superior contacts and contours than the Tofflemire circumferential system.

CT- and MR-based image-based data mining are consistent in the brain

PurposeImage-based data mining (IBDM) is a voxel-based analysis technique to investigate dose–response. Most often, IBDM uses radiotherapy planning CTs because of their broad accessibility, however, it was unknown whether CT provided sufficient soft tissue contrast for brain IBDM. This study evaluates whether MR-based IBDM improves upon CT-based IBDM for studies of children with brain tumours. MethodsWe compared IBDM pipelines using either CT- or MRI-based spatial normalisation in 128 children (ages 3.3–19.7 years) who received photon radiotherapy for primary brain tumours at a single institution. We quantified spatial-normalisation accuracy using contour comparison measures (centre-of-mass separation, average contour distance-to-agreement (DTavg), and Hausdorff distance) at multiple anatomic loci. We performed an end-to-end test of CT- and MRI-IBDM using modified clinical dose distributions and simulated effect labels to detect associations in pre-defined anatomic loci. Accuracy was assessed via sensitivity and specificity. ResultsSpatial normalisation accuracy was comparable for both modalities, with a significant but small improvement for MRI compared to CT in all structures except the brainstem. The median (range) difference between the DTavg for the two pipelines was 0.37 (0.00–2.91) mm. The end-to-end test revealed no significant difference in sensitivity of the IBDM-identified regions for the two pipelines. Specificity slightly improved for MR-IBDM at the 99% significance level. ConclusionCT-based IBDM was comparable to MR-based IBDM, despite a small advantage in spatial normalisation accuracy with MRI. The use of CT-IBDM over MR-IBDM is useful for multi-institutional retrospective IBDM studies, where the availability of standardised MRI data can be limited.

A comparison of preoperative soft tissue contour versus bone accuracy as a predictor of quality of life outcomes in osseous free flap jaw reconstruction using occlusal-based virtual surgical planning

ObjectivesOcclusal based virtual surgical planning (VSP) prioritises placement of endosseous dental implants, over replicating native bone contour. This may compromise facial aesthetics. This study aims to compare function and health-related quality of life (HRQOL) following maxillomandibular reconstruction according to ability to replicate preoperative soft-tissue contour and virtual plan. Materials and methodsPatients who had undergone occlusal based VSP osseous free flap reconstruction of the maxilla or mandible, with high-resolution pre- and postoperative facial computerised tomography imaging, and completion of FACE-Q questionnaire were retrospectively identified. Accuracy of reconstruction compared to preoperative soft tissue contour and virtual plan, was measured using 3DSlicer® and CloudCompare® in three dimensions. Random effects modelling determined associations between bony and soft tissue accuracy and HRQOL/functional domains. ResultsTwenty-two patients met the inclusion criteria. For mandibular and maxillary reconstructions, better soft tissue accuracy was associated with improved appearance (p = 0.048) and appearance distress (p = 0.034). For mandibular reconstructions, better soft tissue accuracy was associated with improved smile (p=0.039) and smile distress (p=0.031). For maxillary reconstructions, better bony accuracy was associated with improved appearance (p=0.023) and drooling distress (p=0.001). Unexpectedly, better bony accuracy was associated with worse eating and drinking (p=0.015), oral competence (p=0.005) and eating distress (p=0.013) in mandibular reconstructions. ConclusionWhilst soft tissue accuracy was associated with better functional and HRQOL outcomes, bone accuracy was associated with worse oral function/distress in mandibular reconstruction. These results need validation but should be considered when performing occlusal-based VSP, which prioritises dental rehabilitation over replicating facial bony contour.

Measurement of Nasal Contour Landmarks in Septorhinoplasties with Special Regard to the Course of Postoperative Swelling Using a Three-Dimensional Camera.

The integration of three-dimensional (3D) cameras into clinical practice for pre-operative planning and post-operative monitoring of rhinoplasties remains controversial. However, this technology offers the advantage of capturing the 3D surface without exposing patients to potentially harmful radiation. Continuous assessment allows the follow-up of swelling patterns, cartilage alignment, and bone remodeling. The primary objective of our study was to quantify changes in nasal structure before and after rhinoplasty by using 3D photography. Our study cohort consisted of 29 patients who underwent open structural rhinoplasty. We used the Artec Space Spider camera to acquire a total of 103 3D images. We collected pre-operative and at least two or three post-operative follow-up scans, which were taken one, three, and six months after surgery. We evaluated paired scans that included various time intervals to improve our understanding of swelling behavior and to ensure an objective analysis of changes. Eleven specific anatomical landmarks were identified for measurement. Two independent raters determined the distances between these landmarks over time. The calculation of intraclass correlation coefficients showed low inter-rater variability. Statistically significant changes over time (p < 0.05) were observed for various anatomical landmarks, including soft tissue nasion, soft tissue orbitale right, soft tissue maxillofrontale left, soft tissue maxillofrontale right, nasal bridge, and nasal break point. Conversely, no significant changes (p > 0.05) were observed in the measurements of soft tissue orbitale left, pronasale, subnasale, alare right, or alare left. A visual assessment was conducted using surface distance maps. The results indicate that the complete decrease in swelling takes at least 6 months or even longer. Additionally, 3D photography can provide an objectively comparable analysis of the face and external contours. Furthermore, it allows for a comparison of external contours and therefore pre- and post-operative differences.

Application of Multi-objective Adjoint-based Aerodynamic Optimisation on Generic Road Vehicle with Rear Spoiler

Finding possible solutions where there are multiple conflicting objectives to be simultaneously satisfied is a challenging situation. Multi-objective optimisation of a rear spoiler on a generic road vehicle model is carried out by using adjoint-based optimisation coupled with Computational Fluid Dynamics. The study aims to reduce the vehicle drag and increase vehicle downforce simultaneously by optimising the shape of the spoiler, by allowing the deformation to achieve the most optimised shape assuming no manufacturing constraint. The OpenFOAM software was used for the solver. A strategy for multi-objective optimisation was proposed by assigning appropriate objective function weight, leading to some possible solutions and Pareto front of the proposed design family. Five optimisation solutions of the non-dominated solution Pareto front resulting from the spoiler shape optimisation are presented, explaining the trade-off between conflicting drag and downforce objectives on the vehicle model. The baseline geometry of the simulation is in good agreement with the experimental measurement. The analysis of the shape changes in the proposed optimisation is deeply investigated in terms of the optimised geometry deformation, velocity contour comparison, recirculating region on the base, pressure coefficient comparison and stream-wise velocity component at the slant region of the model. The adjoint-based optimisation method in the presence study can handle multiple objective optimisations and generate possible optimised spoiler shapes to reduce drag and increase downforce. Free deformation of the shape yields in the unique shapes of the spoiler, enabling to manipulate of the base flow at the rear of the vehicle model.

Hemodynamic Study of Cerebral Arteriovenous Malformation: Newtonian and Non-Newtonian Blood Flow

ObjectiveArteriovenous malformation is a disease of the vascular system that occurs mainly in the cerebral arteries and spine. Numerical simulation as a powerful method is used to investigate the Cerebral Arteriovenous Malformation hemodynamic after occlusion of the abnormality step by step by embolization. MethodsThe CT Angiographic imaging data of two patients are used and a geometric model is extracted by the Mimics software. Numerical simulation of blood flow is performed in both Newtonian and non-Newtonian models. The Navier–Stokes, and continuity governing equations are solved by finite element method using the COMSOL Multiphysics software (the commercial computational fluid dynamics (CFD) simulation software). To validate the numerical results, the real data on blood flow rate in the feeding artery and draining veins are used, as well as angiographic images at different times. ResultsRegarding the comparison of pressure contours for different occlusions of 0, 30, 50, and 90%, by increasing the amount of occlusion in the nidus, there is an increase in the blood pressure. Regarding the comparison of the blood flow velocity in the feeding artery, draining veins, and inside the AVM nidus for Newtonian and non-Newtonian models, there is a significant difference between these two simulations in vessels with smaller dimensions (such as vessels inside the nidus). ConclusionBy increasing the amount of nidus occlusion, the blood pressure is increased, so the blood supply process is better. According to a significant difference between the Newtonian and non-Newtonian simulations in vessels with smaller dimensions (such as vessels inside the nidus), therefore, non-Newtonian simulation should be done for different occlusions of 30, 50, and 90%.

Computer Vision Application: Vehicle Counting and Classification System from Real Time Videos

Traffic analysis is a problem that city planners have been dealing with for years. Smarter methods are developed to analyze traffic and speed up the process. Traffic analysis can record the number of vehicles and vehicle classes in an area at a given time. People have been developing such mechanisms for decades now, but most of them involve using sensors to calculate the direction of moving vehicles and identify vehicles to track vehicle numbers. Although this system has matured over time and is very effective, they are not budget-friendly. The problem is that such systems require periodic maintenance and calibration. Therefore, this project aims to calculate and classify the vehicle based on vision. The system involves capturing frames from video to detect and count vehicles using Gaussian Mixture Model (GMM) background subtraction, then classifying vehicles by comparing contour areas with predicted values. A significant contribution of the paper is the comparison of two classification methods. Classification is done using Contour Comparison (CC) and Bag of Features (BoF) methods

The Investigating Image Registration Accuracy and Contour Propagation for Adaptive Radiotherapy Purposes in Line with the Task Group No. 132 Recommendation.

Image registration is a crucial component of the adaptive radiotherapy workflow. This study investigates the accuracy of the deformable image registration (DIR) and contour propagation features of SmartAdapt, an application in the Eclipse treatment planning system (TPS) version 16.1. The registration accuracy was validated using the Task Group No. 132 (TG-132) virtual phantom, which features contour evaluation and landmark analysis based on the quantitative criteria recommended in the American Association of Physicists in Medicine TG-132 report. The target registration error, Dice similarity coefficient (DSC), and center of mass displacement were used as quantitative validation metrics. The performance of the contour propagation feature was evaluated using clinical datasets (head and neck, pelvis, and chest) and an additional four-dimensional computed tomography (CT) dataset from TG-132. The primary planning and the second CT images were appropriately registered and deformed. The DSC was used to find the volume overlapping between the deformed contours and the radiation oncologist (RO)-drawn contour. The clinical value of the DIR-generated structure was reviewed and scored by an experienced RO to make a qualitative assessment. The registration accuracy fell within the specified tolerances. SmartAdapt exhibited a reasonably propagated contour for the chest and head-and-neck regions, with DSC values of 0.80 for organs at risk. Misregistration is frequently observed in the pelvic region, which is specified as a low-contrast region. However, 78% of structures required no modification or minor modification, demonstrating good agreement between contour comparison and the qualitative analysis. SmartAdapt has adequate efficiency for image registration and contour propagation for adaptive purposes in various anatomical sites. However, there should be concern about its performance in regions with low contrast and small volumes.

Clinical Use of a Commercial Artificial Intelligence-Based Software for Autocontouring in Radiation Therapy: Geometric Performance and Dosimetric Impact.

When autocontouring based on artificial intelligence (AI) is used in the radiotherapy (RT) workflow, the contours are reviewed and eventually adjusted by a radiation oncologist before an RT treatment plan is generated, with the purpose of improving dosimetry and reducing both interobserver variability and time for contouring. The purpose of this study was to evaluate the results of application of a commercial AI-based autocontouring for RT, assessing both geometric accuracies and the influence on optimized dose from automatically generated contours after review by human operator. A commercial autocontouring system was applied to a retrospective database of 40 patients, of which 20 were treated with radiotherapy for prostate cancer (PCa) and 20 for head and neck cancer (HNC). Contours resulting from AI were compared against AI contours reviewed by human operator and human-only contours using Dice similarity coefficient (DSC), Hausdorff distance (HD), and relative volume difference (RVD). Dosimetric indices such as Dmean, D0.03cc, and normalized plan quality metrics were used to compare dose distributions from RT plans generated from structure sets contoured by humans assisted by AI against plans from manual contours. The reduction in contouring time obtained by using automated tools was also assessed. A Wilcoxon rank sum test was computed to assess the significance of differences. Interobserver variability of the comparison of manual vs. AI-assisted contours was also assessed among two radiation oncologists for PCa. For PCa, AI-assisted segmentation showed good agreement with expert radiation oncologist structures with average DSC among patients ≥ 0.7 for all structures, and minimal radiation oncology adjustment of structures (DSC of adjusted versus AI structures ≥ 0.91). For HNC, results of comparison between manual and AI contouring varied considerably e.g., 0.77 for oral cavity and 0.11-0.13 for brachial plexus, but again, adjustment was generally minimal (DSC of adjusted against AI contours 0.97 for oral cavity, 0.92-0.93 for brachial plexus). The difference in dose for the target and organs at risk were not statistically significant between human and AI-assisted, with the only exceptions of D0.03cc to the anal canal and Dmean to the brachial plexus. The observed average differences in plan quality for PCa and HNC cases were 8% and 6.7%, respectively. The dose parameter changes due to interobserver variability in PCa were small, with the exception of the anal canal, where large dose variations were observed. The reduction in time required for contouring was 72% for PCa and 84% for HNC. When an autocontouring system is used in combination with human review, the time of the RT workflow is significantly reduced without affecting dose distribution and plan quality.

Generalizable process monitoring for FFF 3D printing with machine vision

AbstractAdditive manufacturing has experienced a surge in popularity in both commercial and private sectors over the past decade due to the growing demand for affordable and highly customized products, which are often in direct opposition to the requirements of traditional subtractive manufacturing. Fused Filament Fabrication (FFF) has emerged as the most widely-used additive manufacturing technology, despite challenges associated with achieving contour accuracy. To address this issue, the authors have developed a novel camera-based process monitoring method that enables the detection of errors in the printing process through a layer-by-layer comparison of the actual contour and the target contour obtained via G-Code processing. This method is generalizable and can be applied to different printer models with minimal hardware adjustments using off-the-shelf components. The authors have demonstrated the effectiveness of this method in automatically detecting both coarse and small contour deviations in 3D-printed parts.

Modulation of wake evolution, separation, and radiated noise by a cylinder with porous media cladding

In this paper, the effects of porous media parameters on circular cylinder wake flow and radiation noise are investigated using large eddy simulations and Ffowcs Williams–Hawkings acoustic analogy. We performed three-dimensional numerical simulations for flow around the cylinder coated with a porous layer of different pores per inch in a subcritical flow regime (ReD=4.7×104) to explore the control mechanism of porous media on wake and radiation noise. The results show that the application of porous media significantly alters the separation pattern behind the cylinder and stabilizes the shear layer detached from the cylinder. The existence of porous layers leads to the transformation of chaotic and irregular vortex structures into more orderly vortices. Moreover, this study also reveals that the cylinder coated with high pore density can provide the desired noise reduction. The analysis of vortex sound theory indicates that porous media reduces the interaction area and magnitude of the positive and negative Lamb vector divergences, which is beneficial for drag reduction and noise attenuation. In addition, the comparison of sound pressure contours shows that the application of porous media does not change the radiation mode of noise, but the porous media with high pore density helps to decrease the generation of noise and intensity of the sound source.

Formability investigation of perforated austenitic SS 304L sheets using SPIF

Incremental sheet forming (ISF) is a progressive and highly flexible method of producing sheet metallic components in batches of limited quantities. It is also used for making prototypes at a low cost. Advantages of ISF are: higher sheet formability; elimination of molds and dies or use of simple molds and dies; formed parts with a good surface finish; use of commonly available vertical CNC milling machine and the possibility of quick changes in design. The low accuracy of formed parts and slow speed of the process are the disadvantages of ISF. Perforated metallic sheets have many applications in different industries because of their attractive display exposable to the atmospheric air and lighter weight than nonperforated metallic sheets. Its formability varies with the hole dimensions, ligament width, material chemistry, and forming parameters. In this paper, the effects of hole size, and other input parameters on the formability of the sheet are investigated. One millimeter thick SS 304L perforated sheets with 2 mm and 3 mm diameter holes are used for the present work. FLD and FLSD were drawn after performing the straight groove and wall angle tests. The highest formability was observed in the sheet with 2 mm diameter holes. XRD line profile analysis was done and correlated the formability with the crystallite size and dislocation density. SEM micrographs of fracture surfaces were taken and the fractographic parameters were correlated with formability. FE simulation was done using the optimized process parameters and the simulation results were compared with the experimental results. Contour and spiral tool path comparison was done numerically and experimentally.

NUMERICAL SIMULATION OF GAS FLOW PATTERNS AND CHARACTERISTICS OF A CENTRIFUGAL COMPRESSOR

The design of compressors based on one- and two-dimensional flow calculations has reached the limit of development by achieving the maximum efficiency of devices. Further development is possible by conducting expensive experiments or by analyzing the results of the modern mathematical models of three-dimensional flow calculations based on the Reynolds-averaged Navier-Stokes equations. To improve the characteristics of the centrifugal compressor and improve the flow part with the subsequent change in the shape and location of the compressor impeller blades, threedimensional flow calculations were performed. Calculations were made using the Ansys CFX software with a student license. The effect of mesh on the integral flow characteristics is analyzed. There is a qualitative coincidence of the compressor performances, as well as gas flow patterns, and separation zones with experimental data. The research uses a sectoral approach to modeling. Calculations based on different turbulence models were compared and it was found that the models based on the "k – ε" model give practically identical results. Compared with the experimental data of the compressor, the Eddy Viscosity Transport Equation turbulence model showed a significant error in determining the total-to-total polytropic efficiency, this value is underestimated by more than 7 %. Due to an increase in the mass flow rate in the compressor, the velocity in the blade diffuser increases significantly and the flow separates from the blades. Based on the comparison of Mach number contours, in addition to flow separation from the diffuser blades, flow separation from the splitter walls and impeller blades are also observed, even at low mass flow rates. The influence of the sector approach on the calculation results and the mutual location of the impeller sector and the blade diffuser sector require further research, which will be the subject of further research.

Superposition of the Similarity Images by Contour

Superposition of the similarity images is implemented by the methodology with divided estimation of parameters. The offsets along the coordinate axes are estimated in the Cartesian coordinate system. The scale and the rotate are estimated in the log-polar coordinate system. The accurate estimation of parameters of similarity models (offsets, scale and rotate) is achieved by the iteration processing. Optimization of the processing time is achieved by contour comparison instead of the image comparison. The test data for experiment is image with the freight car. The decreasing of the processing time for the modified methodology of “contour comparison” was estimated by comparison with the source methodology of “image comparison”.

Clinical validation of MR imaging time reduction for substitute/synthetic CT generation for prostate MRI-only treatment planning.

Radiotherapy treatment planning based only on magnetic resonance imaging (MRI) has become clinically achievable. Though computed tomography (CT) is the gold standard for radiotherapy imaging, directly providing the electron density values needed for planning calculations, MRI has superior soft tissue visualisation to guide treatment planning decisions and optimisation. MRI-only planning removes the need for the CT scan, but requires generation of a substitute/synthetic/pseudo CT (sCT) for electron density information. Shortening the MRI imaging time would improve patient comfort and reduce the likelihood of motion artefacts. A volunteer study was previously carried out to investigate and optimise faster MRI sequences for a hybrid atlas-voxel conversion to sCT for prostate treatment planning. The aim of this follow-on study was to clinically validate the performance of the new optimised sequence for sCT generation in a treated MRI-only prostate patient cohort. 10 patients undergoing MRI-only treatment were scanned on a Siemens Skyra 3T MRI as part of the MRI-only sub-study of the NINJA clinical trial (ACTRN12618001806257). Two sequences were used, the standard 3D T2-weighted SPACE sequence used for sCT conversion which has been previously validated against CT, and a modified fast SPACE sequence, selected based on the volunteer study. Both were used to generate sCT scans. These were then compared to evaluate the fast sequence conversion for anatomical and dosimetric accuracy against the clinically approved treatment plans. The average Mean Absolute Error (MAE) for the body was 14.98 ± 2.35 HU, and for bone was 40.77 ± 5.51 HU. The external volume contour comparison produced a Dice Similarity Coefficient (DSC) of at least 0.976, and an average of 0.985 ± 0.004, and the bony anatomy contour comparison a DSC of at least 0.907, and an average of 0.950 ± 0.018. The fast SPACE sCT agreed with the gold standard sCT within an isocentre dose of -0.28% ± 0.16% and an average gamma pass rate of 99.66% ± 0.41% for a 1%/1 mm gamma tolerance. In this clinical validation study, the fast sequence, which reduced the required imaging time by approximately a factor of 4, produced an sCT with similar clinical dosimetric results compared to the standard sCT, demonstrating its potential for clinical use for treatment planning.

PO-1616 The importance of regional analysis in contour comparison

PO-1616 The importance of regional analysis in contour comparison

Origami-inspired sandwich structures under low-to-high velocity impacts: A numerical simulation approach

In this study, the ballistic impact performance of sandwich structures with Miura-origami pattern inspired core (MPIC) panels subjected to low-to-high velocity impacts is studied. Sandwich panels with MPIC structure were modeled and finite element analysis was performed using commercially available software LS-DYNA to evaluate their specific energy absorption (SEA) and load-bearing capabilities. A cylindrical indenter (diameter = 10 mm and height = 15 mm) with material property of mild Steel (ρ = 7800 kg/m3) was impacted at three different velocities, i.e., 10 m/s (0.46 J), 50 m/s (11.49 J), 100 m/s (45.95 J) under predefined impact conditions. The obtained results were compared with that of a monolithic solid plate under identical loading conditions and geometrical dimensions. The proposed MPIC design was 93% lighter in weight than the monolithic solid plate. On comparison of stress contours, the monolithic solid plate exhibited regions of high-stress concentration at the impact zone. However, for the MPIC sandwich panel, the stress contour was found to be uniform. For an impact velocity of 100 m/s, the SEA of the MPIC sandwich panel was found to be 1142.6 J/kg, while for the monolithic solid plate, it was obtained as 57.17 J/kg. Eventhough complete penetration of the MPIC sandwich panel occurred for an impact velocity of 100 m/s, the SEA of the MPIC sandwich panels were found to be significantly higher than that of the monolithic solid plate. Since MPIC sandwich panels exhibit enhanced energy dissipation characteristics, they can be an alternative to the conventional monolithic solid plate as light-weight high performance designs for specific applications.

Analytic calculations and synthetic shapes for validation of quantitative contour comparison software.

A high level of variability in reported values was observed in a recent survey of contour similarity measures (CSMs) calculation tools. Such variations in the output measurements prevent meaningful comparison between studies. The purpose of this study was to develop a dataset with analytically calculated gold standard values to facilitate standardization and ensure accuracy of CSM implementations. The dataset was generated in the Digital Imaging and Communications in Medicine (DICOM) format. Both the dataset and the software used for its generation are made publicly available to encourage robust testing of CSM implementations for accuracy, improving consistency between different implementations.