Shape Measurement Research Articles

Advanced Body Measurement Techniques Can Complement Current Methods of Cytotoxic Chemotherapy Dose Prescription

Within chemotherapy, estimates of a patient’s body surface area (BSA) are used to calculate drug dosages. However, the use of BSA for calculating chemotherapy dosage has been heavily criticised in previous literature, with potentially significant implications for the effectiveness and toxicity of treatment. BSA has been found to be a poor indicator of optimal drug exposure that does not account for the complex processes of cytotoxic drug distribution and elimination. In addition, differences in BSA estimates between existing formulae have been shown to be so large that they can affect patients’ mortality, particularly in patients with atypical body types. This uncertainty associated with BSA prediction may decrease the confidence of practitioners when determining chemotherapy dosages, particularly with regards to the risk of excess toxicity from over-dosing, or a reduced anti-cancer effect due to under-dosing. The use of national dose-banding in the UK may in some cases account for possible inaccuracies, but the threshold of variance in this case is small (+/−6%). Advanced body measurement techniques, utilising digital tools such as three-dimensional (3D) surface imaging, capture accurate external dimensions and detailed shape characteristics of the human body. Measures of body shape describe morphological variations that cannot be identified by traditional anthropometric techniques and improve the prediction of total body fat and distribution. It is our view that the use of advanced body measurement techniques can provide practitioners with tools for prescribing chemotherapy dosages that are valid for individuals, regardless of their body type.

Simulating image coaddition with the Nancy Grace Roman Space Telescope – I. Simulation methodology and general results

ABSTRACT The upcoming Nancy Grace Roman Space Telescope will carry out a wide-area survey in the near-infrared. A key science objective is the measurement of cosmic structure via weak gravitational lensing. Roman data will be undersampled, which introduces new challenges in the measurement of source galaxy shapes; a potential solution is to use linear algebra-based coaddition techniques such as imcom that combine multiple undersampled images to produce a single oversampled output mosaic with a desired ‘target’ point spread function (PSF). We present here an initial application of imcom to 0.64 square degrees of simulated Roman data, based on the Roman branch of the Legacy Survey of Space and Time (LSST) Dark Energy Science Collaboration (DESC) Data Challenge 2 (DC2) simulation. We show that imcom runs successfully on simulated data that includes features such as plate scale distortions, chip gaps, detector defects, and cosmic ray masks. We simultaneously propagate grids of injected sources and simulated noise fields as well as the full simulation. We quantify the residual deviations of the PSF from the target (the ‘leakage’), as well as noise properties of the output images; we discuss how the overall tiling pattern as well as Moiré patterns appear in the final leakage and noise maps. We include appendices on interpolation algorithms and the interaction of undersampling with image processing operations that may be of broader applicability. The companion paper (‘Paper II’) explores the implications for weak lensing analyses.

Scalable Feature Extraction and Tracking (SCAFET): a general framework for feature extraction from large climate data sets

Abstract. This study describes a generalized computational mathematical framework, Scalable Feature Extraction and Tracking (SCAFET), that extracts and tracks features from large climate data sets. SCAFET utilizes novel shape-based metrics that can identify and compare features from different mean states, data sets, and between distinct regions. Features of interest such as atmospheric rivers, tropical and extratropical cyclones, and jet streams are extracted by segmenting the data based on a scale-independent bounded variable called the shape index (SI). The SI gives a quantitative measurement of the local geometric shape of the field with respect to its surroundings. Compared to other widely used frameworks in feature detection, SCAFET does not use a posteriori assumptions about the climate model or mean state to extract features of interest and levelize the comparison between different models and scenarios. To demonstrate the capabilities of the method, we illustrate the detection of atmospheric rivers, tropical and extratropical cyclones, sea surface temperature fronts, and jet streams. Cyclones and atmospheric rivers are extracted to show how the algorithm identifies and tracks both the nodes and areas from climate data sets. The extraction of sea surface temperature fronts exemplifies how SCAFET effectively handles curvilinear grids. Last, jet streams are extracted to demonstrate how the algorithm can also detect three-dimensional features. As a generalized framework, SCAFET can be implemented to extract and track many weather and climate features across scales, grids, and dimensions.

Automatic measurement system for large-aperture-angle non-holonomic spherical stitching with laser differential confocal interference.

In response to the urgent need for highly precise and efficient stitching measurements of large-aperture-angle non-holonomic spherical surfaces, a differential confocal interference automatic stitching measurement system for large-aperture-angle non-holonomic spherical surfaces was developed. The system realizes precise positioning of the confocal position through differential confocal precise focusing technology. Through the stitching model, coordinate transformation and error compensation were performed on subaperture data, and the stitching measurement of the spherical surface shape was realized. The positions and postures of the tested samples were adjusted automatically using an automatic adjustment workbench. The stitching measurement accuracy of this measurement system can attain 0.0013λ, relative error can attain 1.36%, and measurement time for eight subaperture stitching is 6min. This system achieves automatic and rapid adjustment of large-aperture-angle spherical elements and high-precision, nondestructive, fast, and automatic measurement of surface stitching.

Experimental study on time-resolved 3D ice accretion shape measurements in large-scale icing wind tunnel

Experimental study on time-resolved 3D ice accretion shape measurements in large-scale icing wind tunnel

Phase-aided online self-correction method for high-accuracy three-dimensional measurement.

The binocular structured light 3D measurement system is widely used in situ industrial inspection and shape measurement, where the system structure is generally unstable due to mechanical loosening or environmental disturbance. Timely corrections to the changing structural parameters thus is an essential task for online high-accuracy measurement, which is difficult for traditional unidirectional fringe projection methods to self-correct the structural change. To this end, we propose an online self-correction method based on the investigation that orthogonal fringe projection can intrinsically relax the constraint on the epipolar geometry relationship and provide bidirectional phases for accurate corresponding point searching. Since orthogonal fringe projection may sacrifice the measurement efficiency, we further design a searching strategy by locally unwrapping one directional phase to reduce the number of projection patterns. Experimental results demonstrate that the proposed method is effective for online self-correction of unstable system structure to achieve high-accuracy 3D measurement under complex measurement environments.

Crystal structure of a layered phosphate molybdate K2Gd(PO4)(MoO4)

The title compound dipotassium gadolinium(III) phosphate(V) molybdate(VI), K2Gd(PO4)(MoO4), was synthesized from a high-temperature melt starting from GdF3 as a source of gadolinium. Its structure is isotypic with other M I 2 M III(M VIO4)(PO4) compounds, where M I = Na, K or Cs, and M III = rare-earth cation, M VI = Mo or W. The three-dimensional framework is built up from [Gd(PO4)(MoO4)] anionic sheets, which are organized by adhesion of [GdPO4] layers and [MoO4] tetrahedra stacked above and below these layers. The interstitial space is occupied by K cations having eightfold oxygen coordination. The polyhedron of GdO8 was estimated to be a triangular dodecahedron by the continuous shape measurement method.

Developing the health effect assessment of landscape (HEAL) Tool: Assessing the health effects of community greenspace morphology design on non-communicable diseases

Neighborhood greenspace benefits health, yet few tools are available for estimating the health consequences of community greenspace design alternatives, especially prior to the implementation of a landscape design plan. Herein we present a machine learning based tool for predicting the prevalence of non-communicable diseases based on landscape design maps at the community scale. We achieve this based on data collected in five major metropolises in the United States. By using high-resolution satellite imagery and remote sensing technologies, landscape spatial design characteristics were extracted through spatial pattern analysis, allowing the measurement of verdancy, fragmentation, connectedness, aggregation, and shape of greenspaces. We established a model to estimate the prevalence of poor mental health, coronary heart disease, stroke, diabetes, chronic obstructive pulmonary disease, and physical inactivity at the census tract level by adopting a combination of random forest decision tree algorithm and spatial Gaussian process models. Model accuracy was found to be significantly higher than ordinary regression models. The model accounted for very high levels of variance in the specified morbidities; viz., poor mental health (97%), heart disease (93%), stroke (93%), diabetes (95%), COPD (94%), and physical inactivity (98%). This tool is implemented using a freely available programming language (R), and we offer the model accessible to the public. This tool enables urban planners and landscape designers to assess and compare the health effects of different greenspace design plans prior to implementation, thus providing policymakers and designers with evidence-rich alternatives during the health-promoting greenspace planning process.

Embedding and cross-sectioning as a sample preparation procedure for accurate and representative size and shape measurement of nanopowders

Reliable measurement of the size of polydisperse, complex-shaped commercial nanopowders is a difficult but necessary task, e.g., for regulatory requirements and toxicity risk assessment. Suitable methods exist for the accurate characterization of the size of non-aggregated, stabilized, spherical and monodisperse nanoparticles. In contrast, industrial nanoscale powders usually require dedicated sample preparation procedures developed for the analysis method of choice. These nano-powders tend to agglomerate and/or aggregate, a behavior which in combination with an innate broad particle size distribution and irregular shape often significantly alters the achievable accuracy of the measured size parameters. The present study systematically tests two commercially available nanoscale powders using different sample preparation methods for correlative analysis by scanning electron microscopy, dynamic light scattering, Brunauer–Emmet–Teller method and differential mobility analysis. One focus was set on the sample preparation by embedding nanoparticles in carbon-based hot-mounting resin. Literature on this topic is scarce and the accuracy of the data extracted from cross sections of these particles is unclearly stated. In this paper systematic simulations on the deviation of the size parameters of well-defined series of nanoparticles with different shapes from the nominal value were carried out and the contributing factors are discussed.

Variable-Frequency Phase Unwrapping for High-Speed 3-D Shape Measurement

Variable-Frequency Phase Unwrapping for High-Speed 3-D Shape Measurement

A Lagrangian theory for galaxy shape statistics

We formulate the Lagrangian perturbation theory of galaxy intrinsic alignments and compute the resulting auto and cross power spectra of galaxy shapes, densities and matter to 1-loop order. Our model represents a consistent effective-theory description of galaxy shape including the resummation of long-wavelength displacements which damp baryon acoustic oscillations, and includes one linear, three quadratic and two cubic dimensionless bias coefficients at this order, along with counterterms and stochastic contributions whose structure we derive. We compare this Lagrangian model against the three-dimensional helicity spectra of halo shapes measured in N-body simulations by ref. [1] and find excellent agreement on perturbative scales while testing a number of more restrictive bias parametrizations. The calculations presented are immediately relevant to analyses of both cosmic shear surveys and spectroscopic shape measurements, and we make a fast FFTLog-based code spinosaurus publicly available at https://github.com/sfschen/spinosaurus.

A Hybrid Approach Based on Unequal Span Segmentation-Clustering for Short-Term Wind Power Forecasting

Because the fluctuation and uncertainty of wind power generation bring severe secure and economic challenges to power systems, wind power forecasting becomes the critical part of the management in power systems. In this paper, a hybrid approach based on unequal span segmentation-clustering is proposed to mine the variation trend information in the wind speed series for improving forecasting performance. Firstly, the wind speed series representation is proposed to accurately represent the major variation trend of the wind speed series. It reduces the influence of the non-stationary and irregular behaviors of the wind speed series on the unequal span segmentation-clustering. Secondly, the shape-position comprehensive evaluation is proposed to combine shape and position measures to evaluate the clustering of the trend segments with unequal length. It identifies the trend segments which have comprehensive similarity on both shape and position to better construct forecasting models. Thirdly, novel bayesian optimization mutation operators are proposed to optimally move or add cut points in the unequal span segmentation. It enhances the local search capability of the unequal span segmentation. By comparing different approaches using wind datasets from two wind farms, the effectiveness and advantages of the proposed approach are demonstrated.

Interfacial rheology of linearly growing polyelectrolyte multilayers at the water-air interface: from liquid to solid viscoelasticity.

Despite the long history of investigations of polyelectrolyte multilayer formation on solid or liquid surfaces, important questions remain open concerning the construction of the first set of layers. These are generally deposited on a first anchoring layer of different chemistry, influencing their construction and properties. We propose here an in-depth investigation of the formation of NaPSS/PAH multilayers at the air/water interface in the absence of a chemically different anchoring layer, profiting from the surface activity of NaPSS. To analyse the mechanical properties of the different layers, we combine recently established analysis techniques of an inflating/deflating bubble exploiting simultaneous shape and pressure measurement: bubble shape elastometry, general stress decomposition and capillary meniscus dynanometry. We complement these measurements by interfacial shear rheology. The obtained results allow us to confirm, first of all, the strength of the aforementioned techniques to characterize complex interfaces with non-linear viscoelastic properties. Furthermore, their sensitivity allows us to show that the multilayer properties are highly sensitive to the temporal and mechanical conditions under which they are constructed and manipulated. We nevertheless identify a robust trend showing a clear transition from a liquid-like viscoelastic membrane to a solid-like viscoelastic membrane after the deposition of 5 layers. We interpret this as the number of layers required to create a fully connected multilayer, which is consistent with previous results obtained on solid or liquid interfaces.

A Multilayer Nested Space Ray Telescope Assembly and Adjustment System Based on Online Monitoring Feedback

In order to adapt to the rapid development of deep space exploration, pulsar navigation and space astronomical observation technology, the development of high-efficiency and high-performance X-ray space telescopes has become one of the hotspots for research in the fields of autonomous spacecraft navigation and astronomical observation. Since the X-ray multilayer nested mirror shells are thin-walled and deformable cylindrical structures with high requirements for surface shape accuracy, a slight change in the position or surface shape will lead to a reduction in the focusing imaging quality, so it is necessary to develop a high-precision assembly and adjustment system based on closed-loop real-time monitoring. In this paper, a multi-layer nested space ray telescope assembly and adjustment system with online monitoring feedback is developed, and a method for precision assembly and adjustment of multi-layer nested mirror shells based on online real-time detection and feedback is proposed, which specifically includes key innovative assembly technologies such as three-dimensional face shape measurement, flexible vacuum adsorption, precision adjustment that have been broken through in the process, and the imaging quality of the focused spot of the mirror shells is evaluated and analyzed in the end. The results of the experiment indicate that the assembly and adjustment of the multilayer nested mirror shells can effectively complete the high-precision assembly, and the relevant results can provide a certain reference significance for the further enhancement of the assembly and adjustment performance of the multilayer nested mirror shells.

High-Speed Phase Structured Light Integrated Architecture on FPGA

Phase-shifting fringe projection profilometry (FPP) in three-dimension (3D) structured light measurement is widely applied in high-accuracy 3D shape measurement scenarios. But motion objects or other dynamic scenarios make the traditional phase-shifting FPP hard to deal with due to its sizable CPU-based execution time. Therefore, an embedded high-speed and high-accuracy phase-shifting FPP system is designed and implemented on FPGAs. The system implements a three-frequency four-step phase-shifting hardware algorithm with RTL-level caching, multi-frame image ping-pong buffering, and data handling, etc. The system exhibits fully-parallel and pipeline processing while behaving with lower resource and power consumption. Measurement experiments indicate that the proposed method can reach high-accuracy real-time 3D shape measurement with a 3D decoding speed of 40.15 fps when the clock frequency is 200MHz, and the image size is 2432×2048.

Factors contributing to the development of choroidal microvasculature dropout in glaucoma suspects and patients with glaucoma

Aims/Purpose: We aimed to characterize and compare the occurrence of MvD between glaucoma suspects and patients with glaucoma. In addition, the factors related to the development of parapapillary MvD in glaucoma suspects and patients with glaucoma were investigated.Methods: Total 150 eyes, 68 eyes of glaucoma suspects and 82 eyes of glaucoma patients were analysed in this study. Disc photography, VF, OCT, HRT, OCTA examinations were performed every year. Student's t‐test and the χ2 test were used to compare continuous and categorical variables, respectively. Slope of OCT, HRT, and VF parameters were calculated as change per year using linear regression. Univariate and multivariate logistic regression analyses were used to identify factors associated with MvD development.Results: Comparison between group who developed MvD and group without MvD, there was a significant difference in the slope of cup volume by OCT, central VF progression, and ONH surface depression measured by HRT. Thinner baseline GCIPL thickness, central VF progression, and the slope of cup shape measures by HRT were found to be significant associated factors to MvD development in multivariate analysis in total subjects. In the regression analysis of glaucoma suspect group, greater axial length and baseline cup volume among the baseline factors and the slope of GCIPL thickness and central VF progression among follow‐up factors were significantly associated with the MvD development. In the glaucoma group, central VF progression and ONH depression among follow‐up elements were observed as significant factors and the baseline factor had little relationship.Conclusions: MvD appears not only as a result of the progression of axonal loss of RGC in glaucoma but may also be developed by structural changes and mechanical susceptibility of the ONH associated with baseline characteristics, including myopia, thin central corneal thickness, and higher baseline IOP. Analysing the structural susceptibility of the ONH can predict the occurrence of MvD, which is can be helpful in predicting the progression of glaucoma.

Multi-Spot Image Denoising Correction and Three-Dimensional Shape Measurement of Cylindrical Shaft Parts Based on Deep Learning

Multi-Spot Image Denoising Correction and Three-Dimensional Shape Measurement of Cylindrical Shaft Parts Based on Deep Learning

Evaluation of Photogrammetry System with Constraints on Camera Position and Attitude for Accurate Shape Measurement of Space Structures

Evaluation of Photogrammetry System with Constraints on Camera Position and Attitude for Accurate Shape Measurement of Space Structures

Color phase order coding and interleaved phase unwrapping for three-dimensional shape measurement with few projected pattern

Color phase order coding and interleaved phase unwrapping for three-dimensional shape measurement with few projected pattern

Homoleptic hexa- and penta-coordinated gallium(I) amide complexes of ruthenium and molybdenum.

Reaction of neutral olefin complexes of ruthenium and molybdenum with GaTMP (TMP = 2,2,6,6-tetramethylpiperidinyl) by substitution leads to the formation of respective five- and six-coordinated homoleptic products. [Ru(GaTMP)5] (1) and [Mo(GaTMP)6] (2) were isolated and characterized. Core structure geometries were analyzed using continuous shape measure, and the complexes were subjected to DFT calculations unveiling competing π-interactions between the transition metal center and the amido substituent with the unoccupied pπ orbitals of the gallium.