Search

This article continues and generalizes the study "On the Similarity of Quasi-Geostrophic Vortices against the Background of Large-Scale Barotropic Currents" [6] (Oceanology, Zhmur, 2024, in print). In continuation of [6], a similar formulation is considered, but for other types of background currents. In the quasi-geostrophic description for small Rossby numbers, the problem of the evolution of an arbitrarily shaped liquid volume with homogeneous potential vorticity of all vortex core particles in an equidistant background flow—horizontal flow with vertical shear and equidistant flow with barotropic and baroclinic components—is presented. Ultimately, the problem boils down to an integrodifferential equation for the evolution of the vortex core boundary. The study of this equation in dimensionless form makes it possible to find a set of dimensionless parameters that determine the similarity condition of the studied vortices. [ABSTRACT FROM AUTHOR]

Most trajectory compression methods primarily focus on geometric similarity between compressed and original trajectories, lacking explainability of compression results due to ignoring semantic information. This paper proposes a spatio-temporal semantic constrained trajectory compression method. It constructs a new trajectory distance measurement model integrating both semantic and spatio-temporal features. This model quantifies semantic features using information entropy and measures spatio-temporal features with synchronous Euclidean distance. The compression principle is to retain feature points with maximum spatio-temporal semantic distance from the original trajectory until the compression rate is satisfied. Experimental results show these methods closely resemble each other in maintaining geometric similarity of trajectories, but our method significantly outperforms DP, TD-TR, and CascadeSync methods in preserving semantic similarity of trajectories. This indicates that our method considers both geometric and semantic features during compression, resulting in the compressed trajectory becoming more interpretable. [ABSTRACT FROM AUTHOR]

Indoor paths conveyed to pedestrians should align with their spatial cognition for a successful wayfinding experience. In this respect, indoor paths and navigation patterns of pedestrians should be geometrically similar. In this study, four navigation networks frequently used in the literature were created for the study area. Then, various geometric similarity measures were calculated for the indoor paths and navigation patterns of the pedestrians. The geometric similarity measures were weighted with the Fuzzy Analytical Hierarchy Process (FAHP) method, and the indoor paths and the navigation patterns of pedestrians were compared with the Technique for Order Preference by Similarity to Ideal Solution (TOPSIS) method in terms of geometric similarity. According to the findings of the experimental study, the Middle Point Relation Structure Segment Entrance (MPRSSE) navigation network was found to be the most similar to navigation patterns of pedestrians for the study area. The MPRSSE navigation network was followed by the Medial Axis Transform (MAT) based navigation network and the Grid based navigation network, respectively. The visibility partitioning-based Universal Circulation Network (UCN) navigation network, which was found to be the most suitable for path length and number of turns criteria in the literature, fell behind in terms of geometric similarity. [ABSTRACT FROM AUTHOR]

The paper proposes a theory of similarity of quasi-geostrophic vortices against the background of large-scale flows. This information is useful when planning laboratory and numerical experiments to study mesoscale and submesoscale vortex dynamics of vortices interacting with currents. Special attention is paid to studying geometric similarity of phenomena. It is revealed that the complete set of dimensionless similarity numbers of baroclinic vortices includes four dimensionless parameters: the dimensionless intensity of the vortex, the geometric similarity of the background flow (the ratio of the relative vorticity to the deformation coefficient of the background flow), the coefficient of horizontal stretching of the vortex core, and the coefficient of vertical oblateness of the vortex core coinciding with the Burger number. To describe the similarity of barotropic vortices against the background of barotropic flows, the number of necessary dimensionless parameters is reduced by one number: the coefficient of vertical oblateness of the vortex core is eliminated from consideration. When studying axisymmetric vortices or vortex structures close to axisymmetric, another geometric parameter of the vortex is eliminated from consideration—the coefficient of horizontal stretching of the vortex core. As a result, the maximum possible set of similarity parameters includes four dimensionless numbers, and the minimum is two. [ABSTRACT FROM AUTHOR]

Introduction: In the treatment of waste water at the "Desembarco del Granma" textile factory there is a neutralization tank, which resembles a continuous reactor with agitation. This equipment uses H2SO4, which must be replaced by a chemical agent with a lower impact on the environment. Objective: To determine the viability of using the existing reactor at the "Desembarco del Granma" textile factory for the neutralization of residual water when using CO2. Materials and Methods: Continuous stirred reactors were compared at laboratory and industrial levels, where the criterion of geometric similarity was considered. The Aspen Plus program was used to simulate the industrial reactor, considering the kinetics obtained at the laboratory level. The fluid package selected was the UNIQUAC. Results and Discussion: The speed at the tip of the impeller is the same for both reactors and the relationship between the diameter of the impeller and that of the tank remains practically constant, so there is geometric similarity between the reactors. The pH of the residual water neutralized with CO2 was 7.2, showing adequate neutralization. Conclusions: Geometric similarity was evidenced between continuous stirred reactors at laboratory and industrial levels. The pH of the neutralized wastewater in the industrial reactor, determined by simulation, was 7.2. It was proven, with the use of Aspen Plus, that the textile company's industrial reactor can be used for the wastewater neutralization process when CO2 is used instead of H2SO4. [ABSTRACT FROM AUTHOR]

Introduction: Muscle cross-sectional area is an important variable for understanding force generating potential and locomotor adaptation. Geometric scaling predicts area scales proportionally to body mass[sup 2/3]. Previous research has quantified scaling relationships between hindlimb musculature and mass in apes, but these relationships have not been clearly established in humans. Scaling in the human lower-limb is likely influenced by bipedalism and dimorphism in lean and total body mass between the sexes. Methods: To investigate these relationships, cross-sectional area in 20 muscles of the lower-limb were obtained through MRI in twenty-eight (14 female, 14 male) participants and measured in Analyze 14.0. Log transformed muscle cross-sectional areas were grouped by function (gluteals, knee extensors, hamstrings, biarticulate knee/hip flexors, plantarflexors), and least-squares regressions were calculated for each group against log-body mass. Results: All muscle groups were significantly (p < 0.001) correlated with mass (0.56 < r² < 0.70) and, except for the gluteals, all groups scaled with positive allometry with slopes outside the 95% CI reported in the literature for apes. Correlations and slopes were lower for females (0.05 < r² < 0.62; 0.4 < b < 1.0), than males (0.56 < r² < 0.79: 0. 7< b < 1.9) in all muscle groups, but there were no statistically significant differences in slope except for the tensor fasciae latae and the hamstrings. However, including sex as a predictor in multiple regression analysis increased the explained variance in cross-sectional area by 1-18% across functional muscle groups. Discussion: These results suggest human lower-limb muscle scaling has responded to force production requirements of bipedalism, but differences in lean and total mass do not clearly impact allometric equations in males and females. [ABSTRACT FROM AUTHOR]

Copyright of China Synthetic Fiber Industry is the property of Sinopec Baling Petrochemical Company and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Most trajectory compression methods primarily focus on geometric similarity between compressed and original trajectories, lacking explainability of compression results due to ignoring semantic information. This paper proposes a spatio-temporal semantic constrained trajectory compression method. It constructs a new trajectory distance measurement model integrating both semantic and spatio-temporal features. This model quantifies semantic features using information entropy and measures spatio-temporal features with synchronous Euclidean distance. The compression principle is to retain feature points with maximum spatio-temporal semantic distance from the original trajectory until the compression rate is satisfied. Experimental results show these methods closely resemble each other in maintaining geometric similarity of trajectories, but our method significantly outperforms DP, TD-TR, and CascadeSync methods in preserving semantic similarity of trajectories. This indicates that our method considers both geometric and semantic features during compression, resulting in the compressed trajectory becoming more interpretable.

Introduction: Muscle cross-sectional area is an important variable for understanding force generating potential and locomotor adaptation. Geometric scaling predicts area scales proportionally to body mass2/3. Previous research has quantified scaling relationships between hindlimb musculature and mass in apes, but these relationships have not been clearly established in humans. Scaling in the human lower-limb is likely influenced by bipedalism and dimorphism in lean and total body mass between the sexes.Methods: To investigate these relationships, cross-sectional area in 20 muscles of the lower-limb were obtained through MRI in twenty-eight (14 female, 14 male) participants and measured in Analyze 14.0. Log transformed muscle cross-sectional areas were grouped by function (gluteals, knee extensors, hamstrings, biarticulate knee/hip flexors, plantarflexors), and least-squares regressions were calculated for each group against log-body mass.Results: All muscle groups were significantly (p < 0.001) correlated with mass (0.56 < r2 < 0.70) and, except for the gluteals, all groups scaled with positive allometry with slopes outside the 95% CI reported in the literature for apes. Correlations and slopes were lower for females (0.05 < r2 < 0.62; 0.4 < b < 1.0), than males (0.56 < r2 < 0.79: 0. 7< b < 1.9) in all muscle groups, but there were no statistically significant differences in slope except for the tensor fasciae latae and the hamstrings. However, including sex as a predictor in multiple regression analysis increased the explained variance in cross-sectional area by 1-18% across functional muscle groups.Discussion: These results suggest human lower-limb muscle scaling has responded to force production requirements of bipedalism, but differences in lean and total mass do not clearly impact allometric equations in males and females.

In the early stages of engineering design, multitudes of feasible designs can be generated using structural optimization methods by varying the design requirements or user preferences for different performance objectives. Data mining such potentially large datasets is a challenging task. An unsupervised data-centric approach for exploring designs is to find clusters of similar designs and recommend only the cluster representatives for review. Design similarity can be defined not only on a purely functional level but also based on geometric properties, such as size, shape, and topology. While metrics such as chamfer distance measure the geometrical differences intuitively, it is more useful for design exploration to use metrics based on geometric features, which are extracted from high-dimensional 3D geometric data using dimensionality reduction techniques. If the Euclidean distance in the geometric features is meaningful, the features can be combined with performance attributes resulting in an aggregate feature vector that can potentially be useful in design exploration based on both geometry and performance. We propose a novel approach to evaluate such derived metrics by measuring their similarity with the metrics commonly used in 3D object classification. Furthermore, we measure clustering accuracy, which is a state-of-the-art unsupervised approach to evaluate metrics. For this purpose, we use a labeled, synthetic dataset with topologically complex designs. From our results, we conclude that Pointcloud Autoencoder is promising in encoding geometric features and developing a comprehensive design exploration method. [ABSTRACT FROM AUTHOR]

Two adjacent glaciers collapsed consecutively in the Western Xizang Autonomous Region, China, on July 17 and September 21, 2016, presumably triggered by relatively intensive climate change in this region, leading to massive downstream ice and mud avalanches. After these twin glacier collapses, there have been many researches, which mainly focus on the physical characteristics of these two glaciers while lack the differences between them and the other glaciers. In this study, the geometric features and energy distribution along the glacier centerlines are investigated to identify the differences between these two collapsed glaciers and other glaciers in the western Tibetan Plateau. The anomaly of climate change is presumed to be the trigger of the twin glacier collapses in accordance with existing research results, whereas in this study, the striking geometric similarity between the centerlines of the twin glaciers, which is quantitatively interpreted by the Fréchet distance among the glacier centerlines, unearth some novel mechanisms. The essential point in these new mechanisms is the energy distribution along the glacier centerlines. A hypothesis based on the principle of energy conservation is derived to demonstrate the mechanisms and dynamic processes of the glacier collapses. Furthermore, on the basis of the geometric similarity and energy distribution of the glacier centerlines, a risk assessment of glacier collapse in the western Tibetan Plateau is implemented to facilitate glacier disaster prevention.

Due to the potential value in many areas, such as e-commerce and inventory management, fabric image retrieval, which is a special case of content-based image retrieval, has recently become a research hotspot. As a major category of textile fabrics, patterned fabrics have a diverse and complex appearance, making the retrieval task more challenging. To address this situation, this paper proposes a novel approach for patterned fabric based on the non-subsampled contourlet transform (NSCT) feature descriptor and relevance feedback technique. To integrate the color information into the NSCT feature descriptor, we extract the feature of patterned fabric images in HSV color space. An outlier rejection-based parametric relevance feedback algorithm is employed to adjust the similarity matrix to improve the retrieval results. The experimental results not only show the effectiveness of the proposed approach but also demonstrate that it can significantly improve the performance of the retrieval system compared to other state-of-the-art algorithms. [ABSTRACT FROM AUTHOR]

Abstract Background Currently the combination of molecular tools, imaging techniques and analysis software offer the possibility of studying gene activity through the use of fluorescent reporters and infer its distribution within complex biological three-dimensional structures. For example, the use of Confocal Scanning Laser Microscopy (CSLM) is a regularly-used approach to visually inspect the spatial distribution of a fluorescent signal. Although a plethora of generalist imaging software is available to analyze experimental pictures, the development of tailor-made software for every specific problem is still the most straightforward approach to perform the best possible image analysis. In this manuscript, we focused on developing a simple methodology to satisfy one particular need: automated processing and analysis of CSLM image stacks to generate 3D fluorescence profiles showing the average distribution detected in bacterial colonies grown in different experimental conditions for comparison purposes. Results The presented method processes batches of CSLM stacks containing three-dimensional images of an arbitrary number of colonies. Quasi-circular colonies are identified, filtered and projected onto a normalized orthogonal coordinate system, where a numerical interpolation is performed to obtain fluorescence values within a spatially fixed grid. A statistically representative three-dimensional fluorescent pattern is then generated from this data, allowing for standardized fluorescence analysis regardless of variability in colony size. The proposed methodology was evaluated by analyzing fluorescence from GFP expression subject to regulation by a stress-inducible promoter. Conclusions This method provides a statistically reliable spatial distribution profile of fluorescence detected in analyzed samples, helping the researcher to establish general correlations between gene expression and spatial allocation under differential experimental regimes. The described methodology was coded into a MATLAB script and shared under an open source license to make it accessible to the whole community.

Polygon similarity can play an important role in geographic information retrieval, map matching and updating, and spatial data mining applications. Geographic information science (GIS) represents various spatial objects as polygons, including simple polygons and polygons with holes, as well as multipolygons. Spatial objects of multipolygons possess complex structure which makes it difficult to assess their similarity. This study develops a method based on convex hulls and position graphs to measure the similarity between multipolygons. The proposed method first finds correspondences between subpolygons in the two multipolygons based on a control polygon. Thereafter, the method constructs a position graph to denote the distribution of these subpolygons and applies a turning function to compute the similarity between various graphs. Fourier transformation and moment invariants were combined to characterize the different matching relationships among subpolygons. The experiments involve three different kinds multipolygons to verify the effectiveness and robustness of proposed method. The experiments show that this approach effectively measures similarity between multipolygons. Moreover, the proposed method accounts for the relationships across the entire complex geometrical shape and components of multipolygon during measuring similarity. [ABSTRACT FROM AUTHOR]

The literature reports preservice teachers' overuse of proportionality when solving geometric similarity problems with nonproportional relationships. Changing this type of error is reported as difficult even after applying certain interventions. As a solution to this type of error, this study used augmented reality activities to facilitate the development of preservice mathematics teachers' proportional reasoning. The data of this qualitative study included 17 preservice teachers' written responses to a paper-and-pencil test with five problems, which had been applied before and after the implementation of the augment reality activities, and video recordings collected during the augment reality implementation process. A case study methodology was used in designing the study in which the collected data were analyzed using a content analysis method. The preservice teachers' first test responses showed that although they were good at solving problems with regular figures, they had difficulty solving the problem with irregular figures. In this specific problem, the preservice teachers expected a proportional relationship between the areas of the two irregular figures. Their difficulties appeared to be a result of not being able to calculate the areas of these two figures by tiling or multiplying length and width that they used for regular figures. After the implementation of the augmented reality activities, which provided a dynamic representation of similar figures, the preservice teachers' overuse of proportionality drastically decreased. This finding suggested the contribution of the augmented reality technology on the development of the preservice teachers' proportional reasoning. [ABSTRACT FROM AUTHOR]

Geometric similarity plays an important role in geographic information retrieval, map matching, and data updating. Many approaches have been developed to calculate the similarity between simple features. However, complex group objects are common in map and spatial database systems. With a micro scene that contains different types of geographic features, calculating similarity is difficult. In addition, few studies have paid attention to the changes in a scene’s geometric similarity in the process of generalization. In this study, we developed a method for measuring the geometric similarity of micro scene generalization based on shape, direction, and position. We calculated shape similarity using the hybrid feature description, and we constructed a direction Voronoi diagram and a position graph to measure the direction similarity and position similarity. The experiments involved similarity calculation and quality evaluation to verify the usability and effectiveness of the proposed method. The experiments showed that this approach can be used to effectively measure the geometric similarity between micro scenes. Moreover, the proposed method accounts for the relationships amongst the geometrical shape, direction, and position of micro scenes during cartographic generalization. The simplification operation leads to obvious changes in position similarity, whereas delete and merge operations lead to changes in direction and position similarity. In the process of generalization, the river + islands scene changed mainly in shape and position, the similarity change in river + lakes occurred due to the direction and location, and the direction similarity of rivers + buildings and roads + buildings changed little.

This paper presents a novel technique called correspondence selection for rigid transformations in order to effectively refine keypoint matches in rigid image registration. The proposed technique mainly lies in the following two components. First, keypoint matches are ranked and selected by the distance ratio between the best match and the second best match. Second, keypoint matches are further selected by ranking the geometric similarity between corresponding keypoint triplets. These two components enhance the discriminative power of potential keypoint matches in a progressive way. The proposed technique is generally applicable to affine rigid image registration. Experiments have been conducted using a set of benchmark datasets in the field of image registration, indicating that the proposed technique is very effective and achieves the state-of-the-art performance in refining keypoint matches for affine rigid image registration.

Copyright of Coal Science & Technology (0253-2336) is the property of Coal Science & Technology and its content may not be copied or emailed to multiple sites or posted to a listserv without the copyright holder's express written permission. However, users may print, download, or email articles for individual use. This abstract may be abridged. No warranty is given about the accuracy of the copy. Users should refer to the original published version of the material for the full abstract. (Copyright applies to all Abstracts.)

Background: Currently the combination of molecular tools, imaging techniques and analysis software offer the possibility of studying gene activity through the use of fluorescent reporters and infer its distribution within complex biological three-dimensional structures. For example, the use of Confocal Scanning Laser Microscopy (CSLM) is a regularly-used approach to visually inspect the spatial distribution of a fluorescent signal. Although a plethora of generalist imaging software is available to analyze experimental pictures, the development of tailor-made software for every specific problem is still the most straightforward approach to perform the best possible image analysis. In this manuscript, we focused on developing a simple methodology to satisfy one particular need: automated processing and analysis of CSLM image stacks to generate 3D fluorescence profiles showing the average distribution detected in bacterial colonies grown in different experimental conditions for comparison purposes. Results: The presented method processes batches of CSLM stacks containing three-dimensional images of an arbitrary number of colonies. Quasi-circular colonies are identified, filtered and projected onto a normalized orthogonal coordinate system, where a numerical interpolation is performed to obtain fluorescence values within a spatially fixed grid. A statistically representative three-dimensional fluorescent pattern is then generated from this data, allowing for standardized fluorescence analysis regardless of variability in colony size. The proposed methodology was evaluated by analyzing fluorescence from GFP expression subject to regulation by a stress-inducible promoter. Conclusions: This method provides a statistically reliable spatial distribution profile of fluorescence detected in analyzed samples, helping the researcher to establish general correlations between gene expression and spatial allocation under differential experimental regimes. The described methodology was coded into a MATLAB script and shared under an open source license to make it accessible to the whole community. [ABSTRACT FROM AUTHOR]

Well-established techniques exist for measuring the similarity of space–time paths. These measures support clustering and aggregation of space–time paths as well as moving objects database queries based on similar movement patterns or semantics. Little attention has been paid, however, to the analogous problem of measuring space–time prism (STP) similarity, despite comparable applications. This article presents and evaluates a method for measuring STP similarity through dimensionality reduction that leverages their inherent temporal ordering. The technique sweeps an STP along the time axis and derives one-dimensional temporal signatures based on a measured STP property that captures its geometry or semantics. These temporal signatures can be visualized directly as curves. We can also apply existing space–time path similarity measures to these signatures. To demonstrate the feasibility of this approach, we perform two sets of experiments measuring geometric and semantic similarity among STPs and assess the information within these curves using visualization, Fréchet distances, and clustering techniques. Results suggest that the temporal signature curves capture meaningful similarities and differences among STPs. [ABSTRACT FROM AUTHOR]

The problem of modeling the process of separation of suspensions and emulsions in a centrifugal field under the condition of geometric and hydrodynamic similarity of the parameters of hydrocyclones installed in a battery is considered. An example of the calculation of the necessary number of hydrocyclones providing the required degree of purification is given. [ABSTRACT FROM AUTHOR]

Objectives Applying geometric similarity predictions of body dimensions to specific occupational groups has the potential to reveal useful ergonomic and health implications. This study assessed a representative sample of the male UK offshore workforce, and examined how body dimensions from sites typifying musculoskeletal development or fat accumulation, differed from predicted values. Methods A cross sectional sample was obtained across seven weight categories using quota sampling, to match the wider workforce. In total, 588 UK offshore workers, 84 from each of seven weight categories, were measured for stature, mass and underwent 3D body scans which yielded 22 dimensional measurements. Each measurement was modeled using a body-mass power law (adjusting for age), to derive its exponent, which was compared against that predicted from geometric similarity. Results Mass scaled to stature 1.73 (CI: 1.44-2.02). Arm and leg volume increased by mass0.8, and torso volume increased by mass1.1 in contrast to mass 1.0 predicted by geometric similarity. Neck girth increased by mass 0.33 as expected, while torso girth and depth dimensions increased by mass0.53-0.72, all substantially greater than assumed by geometric similarity. Conclusions After controlling for age, offshore workers experience spectacular 'super-centralization' of body shape, with greatest gains in abdominal depth and girth dimensions in areas of fat accumulation, and relative dimensional loss in limbs. These findings are consistent with the antecedents of sarcopenic obesity, and should be flagged as a health concern for this workforce, and for future targeted research and lifestyle interventions. [ABSTRACT FROM AUTHOR]

Modeling and scaling assume significance in micro scale combustion due to limited availability of experimental data for the design of microcombustors. In this study, mathematical modeling and detailed computations of an annular microcombustor were employed to obtain scaling laws. Constant inlet velocity and residence time scaling were used for four geometrically similar configurations in the 0.42–1 mm range, covering the quenching limit of stoichiometric hydrogen-air flames. Based on the scaling arguments and a mathematical model, Graetz number emerged as a possible correlating parameter and enabled the formulation of a general correlation between Graetz number and thermal efficiency that could be useful as a scaling law in design process. Computations involving a wide range of operating parameters, equivalence ratio: 0.5–1.7, inlet Reynolds number: 127–1379, and inlet temperature: 300–600 K, were included in the analysis. The procedure developed in this work could also be used to lend credence to the findings of this study and extend the results to other geometries of microcombustors. [ABSTRACT FROM AUTHOR]

Divergent chimney is proposed to be an alternative for Solar Chimney Power Plants (SCPPs) because of their reported remarkable improvement in power output over cylindrical chimneys. However, the power output of divergent SCPPs in those studies changed from several percentage to >100 times higher than that of cylindrical ones. In our hypothesis, this large deviation was related to the various configurations of the SCPPs examined. Therefore, this paper examined comprehensively the effect of geometry of divergent chimneys on system performance of SCPPs to further reveal their hydrodynamic features. The geometric parameters under investigation included the area ratio (AR) of chimney exit over entrance, the divergent angle (DA) of chimney wall and the size of system. Our numerical simulations indicated a parabolic tendency in the performance of the divergent SCPPs when increasing the ARs (or DAs). Reasons for this tendency were proposed based on its hydro- and thermo-interaction. Furthermore, the normalized power output showed good consistency among the SCPPs with different sizes when geometric similarity was adopted to the entire system geometry. The similar normalized outputs found were almost insensitive to the variations in the solar insolation. These outcomes would be a valuable reference for designing SCPPs with divergent chimneys. [ABSTRACT FROM AUTHOR]