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"image analysis methods"
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Pavement Texture–Friction Relationship Establishment via Image Analysis Methods
Pavement surface texture is one of the prevailing factors for friction realization on pavement surfaces. In this paper, an overview of pavement texture properties related to the pavement frictional response is given. Image analysis methods used for pavement texture characterization are thoroughly analyzed together with their potential for the establishment of a pavement texture–friction relationship. Digital pavement surface models derived from photogrammetry or laser scanning methods enable the extraction of texture parameters comparable to the ones acquired by common pavement surface measuring techniques. This paper shows the results of a preliminary small-scale research study of the pavement texture–friction relationship. This research was performed in a laboratory which produced asphalt samples, primarily to analyze the potential of developing a methodology for the digital pavement texture model setup. Furthermore, the relationship between selected 2D texture parameters calculated from the digital texture model and measured friction coefficient expressed as SRT value was analyzed. A significant correlation was established for standard texture indicator mean profile depth (MPD) and SRT values (R = 0.81). Other texture parameters showed moderate correlation with the frictional response of the surface, with absolute values of correlation coefficients varying from 0.7 to 0.75. A further analysis of this relationship will be performed by inclusion of other texture parameters that can be determined from the digital texture model acquired by the established methodology.
Journal Article
A Comparative Study on a Novel Quality Assessment Protocol Based on Image Analysis Methods for Color Doppler Ultrasound Diagnostic Systems
Color Doppler (CD) imaging is widely used in diagnostics since it allows real-time detection and display of blood flow superimposed on the B-mode image. Nevertheless, to date, a shared worldwide standard on Doppler equipment testing is still lacking. In this context, the study herein proposed would give a contribution focusing on the combination of five test parameters to be included in a novel Quality Assessment (QA) protocol for CD systems testing. A first approach involving the use of the Kiviat diagram was investigated, assuming the diagram area, normalized with respect to one of the gold standards, as an index of the overall Doppler system performance. The QA parameters were obtained from the post-processing of CD data through the implementation of custom-written image analysis methods and procedures, here applied to three brand-new high-technology-level ultrasound systems. Experimental data were collected through phased and convex array probes, in two configuration settings, by means of a Doppler flow phantom set at different flow rate regimes. The outcomes confirmed that the Kiviat diagram might be a promising tool applied to quality controls of Doppler equipment, although further investigations should be performed to assess the sensitivity and specificity of the proposed approach.
Journal Article
A Novel Artificial Intelligence-Based Approach for Quantitative Assessment of Angiogenesis in the Ex Ovo CAM Model
Angiogenesis is a highly regulated process. It promotes tissue regeneration and contributes to tumor growth. Existing therapeutic concepts interfere with different steps of angiogenesis. The quantification of the vasculature is of crucial importance for research on angiogenetic effects. The chorioallantoic membrane (CAM) assay is widely used in the study of angiogenesis. Ex ovo cultured chick embryos develop an easily accessible, highly vascularised membrane on the surface. Tumor xenografts can be incubated on this membrane enabling studies on cancer angiogenesis and other major hallmarks. However, there is no commonly accepted gold standard for the quantification of the vasculature of the CAM. We compared four widely used measurement techniques to identify the most appropriate one for the quantification of the vascular network of the CAM. The comparison of the different quantification methods suggested that the CAM assay application on the IKOSA platform is the most suitable image analysis application for the vasculature of the CAM. The new CAM application on the IKOSA platform turned out to be a reliable and feasible tool for practical use in angiogenesis research. This novel image analysis software enables a deeper exploration of various aspects of angiogenesis and might support future research on new anti-angiogenic strategies for cancer treatment.
Journal Article
Free drying shrinkage performance of Pinus sylvestris L. under different temperature and humidity conditions
Efficient utilization of wood is inseparable from high-quality drying, and analysis of its free shrinkage performance is essential to optimize the drying process. This study took Pinus sylvestris L. sawn timber (500 mm×200 mm×50 mm) as the research object and adopted the image analysis method to analyze the influence rules of different temperatures and axial positions of the test material on the free dry shrinkage coefficient of each layer of specimens in the thickness direction. The free shrinkage coefficients of each layer in the thickness direction of the test material decreased from the maximum value of the first layer near the tangential direction (0.282%, 0.275%, 0.267%, at 60 °C, 80 °C, and 100 °C, respectively) to the minimum value of the ninth layer near the radial direction (0.248%, 0.249%, 0.227%); except for the near-radial layers, when temperature increased from 60 °C to 100 °C the free shrinkage coefficients of other representative layers decreased with increased temperature. The first layer’s free shrinkage coefficient decreased from 0.282% to 0.267%, and the fifth layer decreased from 0.264% to 0.243%. The difference of free shrinkage coefficients between corresponding layers at different axial positions of the test material was less than 0.017%, and the size stability of the corresponding layers at axial positions was high.
Journal Article
Spirality: A Novel Way to Measure Spiral Arm Pitch Angle
We present the MATLAB code Spirality, a novel method for measuring spiral arm pitch angles by fitting galaxy images to spiral templates of known pitch. Computation time is typically on the order of 2 min per galaxy, assuming 8 GB of working memory. We tested the code using 117 synthetic spiral images with known pitches, varying both the spiral properties and the input parameters. The code yielded correct results for all synthetic spirals with galaxy-like properties. We also compared the code’s results to two-dimensional Fast Fourier Transform (2DFFT) measurements for the sample of nearby galaxies defined by DMS PPak. Spirality’s error bars overlapped 2DFFT’s error bars for 26 of the 30 galaxies. The two methods’ agreement correlates strongly with galaxy radius in pixels and also with i-band magnitude, but not with redshift, a result that is consistent with at least some galaxies’ spiral structure being fully formed by z=1.2, beyond which there are few galaxies in our sample. The Spirality code package also includes GenSpiral, which produces FITS images of synthetic spirals, and SpiralArmCount, which uses a one-dimensional Fast Fourier Transform to count the spiral arms of a galaxy after its pitch is determined. All code is freely available.
Journal Article
Spatiotemporal segmentation of contraction waves in the extra-embryonic membranes of the red flour beetle
Background
In this paper, we introduce an image analysis approach for spatiotemporal segmentation, quantification, and visualization of movement or contraction patterns in 2D+t and 3D+t microscopy recordings of biological tissues. The development of this pipeline was motivated by the observation of contraction waves in the extra-embryonic membranes of the red flour beetle
Tribolium castaneum
. These contraction waves are a novel finding, whose origin and function are not yet understood. The objective of the proposed approach is to analyze the dynamics of the extra-embryonic membranes in order to provide quantitative evidence for the existence of contraction waves during late stages of embryonic development.
Results
We apply the pipeline to live-imaging data of
Tribolium
embryonic development recorded with light-sheet fluorescence microscopy. The proposed pipeline integrates particle image velocimetry (PIV) for quantitative movement analysis, surface detection, tissue cartography, and algorithmic identification of characteristic movement dynamics. We demonstrate that our approach reliably and efficiently detects contraction waves in both 2D+t and 3D+t recordings and enables automated quantitative analyses, such as measuring the area involved in contractile behavior, wave duration and frequency, spatiotemporal location of the contractile regions, and their relation to the underlying velocity distribution.
Conclusions
The pipeline will be employed in future work to conduct a large-scale characterization and quantification of contraction wave behavior in
Tribolium
development and can be readily adapted for the identification and segmentation of characteristic tissue dynamics in other biological systems.
Journal Article
Minimally invasive therapy for reconstruction of lost interdental papilla by using injectable hyaluronic acid filler
Background and Aim: Reconstruction of interdental papillae (IDP) is among the most difficult periodontal therapy. Papillary recession is multifactorial, and several surgical, nonsurgical, and minimally invasive techniques have been suggested. The purpose of this study was to evaluate the clinical application of injectable hyaluronic acid (HA) gel for the reconstruction of IDP in Nordland and Tarnow's Class I and II papillary recession cases. Materials and Methods: In the present in vivo clinical trial, 7 patients (2 males, 5 females) with 25 defects were selected. A volume of 0.2 ml HA gel was injected at the respective areas and massaged for 2-3 min. Photographs were obtained, and the assessment of the data was performed clinically (CP-GM, interproximal width [IPW]) and by Image analysis software (black triangle height [BTH], black triangle width [BTW]). Comparison of mean values was performed using the analysis of variance, followed by Post hoc Bonferroni test. Value of P ≤ 0.05 was considered statistically significant. Results: Application of HA gel for the reconstruction of IDP was successful in 6 months. CP-GM, BTH, IPW, and BTW showed a statistically significant difference from baseline to 3 and 6 months interval (P = 0.01). Post hoc Bonferroni test for CP-GM, BTH, BTW, and IPW revealed a statistically significant difference from baseline to 3 months (P ≤ 0.05) and 6 months (P ≤ 0.05) and a nonsignificant difference at 3-6 months (P ≥ 0.05). Conclusion: Injectable HA gel is a promising minimally invasive therapy for enhancing papillary esthetics.
Journal Article
Sentinel-2 satellite image application for establishing a coral reef distribution map in Bai Tu Long National Park, Quang Ninh Province, Vietnam
Coral reef ecosystems are crucial in coastal areas, providing valuable ecosystem services to humans. They are highly biodiverse and act as significant carbon sinks. Coral reef ecosystem conservation is a pressing issue for the world's most vulnerable ecosystems. Mapping coral reef ecosystems using satellite imagery enables informed decision-making for their restoration and protection, facilitating effective management strategies. With the help of machine-learning models and object-based image analysis (OBIA), this study constructed a map showing where coral reef ecosystems are found in Bai Tu Long National Park, Vietnam. The map was created using Sentinel-2 satellite images. The classification results revealed an overall accuracy (OA) of 91.70%, corresponding to a kappa coefficient of 0.89. The highest spectral reflection characteristic for coral reef ecosystems is in the blue spectral band and the lowest is in the SWIR2 spectral band. To understand the composition of these reefs, field surveys were conducted. The results of field surveys revealed that the coral reef ecosystem in Bai Tu Long National Park included nine families, 20 varieties and 32 species. Finally, this study has shown that a map of the distribution of coral reef ecosystems via satellite images and an object-based image analysis method combined with a machine-learning model is a valuable tool for the management and conservation of coral reef ecosystems. The findings of this study play an important role in providing data for the restoration and conservation of coral reef ecosystems in coastal areas.
Journal Article
Influence of Polymer Modification on the Microstructure of Shielding Concrete
In this paper an analysis of the influence of polymer modification on the microstructure, shielding properties against neutrons, and compressive strength of heavy-weight magnetite concrete is carried out. The modifications involve the addition of acrylic or epoxy dispersions as well as micro- or/and macrofibers. A computer image analysis method is used to evaluate the microstructure of concretes and parameters of pore structure are calculated; these parameters include relative volume fraction, relative specific surface area, and pore arrangement ratios, including a proprietary ratio based on Voronoi tessellation. An assessment of significance of differences between stereological parameters of reference concrete and polymer modified concretes, as well as the impact of polymer form (dispersion or fibers) on shielding properties and compressive strength is carried out using Student’s t-test. The results show that except for the effect of the addition of both polypropylene micro- and macrofibers on the relative volume of pores, all other modifications result in statistically significant changes in the values of stereological parameters. Nevertheless, it is shown that neither polymer dispersions nor fibers have a statistically significant impact on shielding properties, but that they do influence compressive strength.
Journal Article