Projection Surface Research Articles

Quantitative anatomy of the infraspinatus muscle in the human fetus.

The study presents one of the six scapulohumeral muscles, which occupies most of the osteofibrous infraspinatus compartment. Along with the supraspinatus, teres minor and subscapularis muscles, the infraspinatus muscle contributes to the rotator cuff. It protects the posterior aspect of the articular capsule of the shoulder joint, adducts and externally rotates the arm. The aim of the study was to perform the quantitative analysis of the infraspinatus muscle in human fetuses and to elaborate growth dynamics for its morphometric parameters. Using anatomical dissection, digital image analysis (NIS Elements AR3.0) and statistics (Student's t-test, regression analysis), the vertical, transverse and oblique diameters, muscle circumference and projection surface area of the infraspinatus muscle were measured in 36human fetuses of both sexes (17♂, 19♀) aged 18-30weeks. The infraspinatus muscle revealed neither sex nor laterality differences. All examined morphometric parameters of the infraspinatus muscle increased commensurately in accordance with the following linear functions: y=-4.024 + 0.903×Age ± 0.621 (R²=0.96) for transverse diameter, y=-3.089 + 1.321×Age ± 0.897 (R²=0.97) for vertical diameter, y=-1.161 + 0.632×Age ± 0.444 (R²=0.97) for oblique diameter, y=-13.575 + 3.851×Age ± 1.938 (R²=0.98) for muscle circumference and y=-293.512 + 23.228×Age ±19.650 (R²=0.95) for projection surface area.

Increasing the space–bandwidth product of holographic displays by segmenting and combining phase masks

This paper presents a method for enlarging holographic images under the constraints of spatial light modulators. The proposed method involves using a modified Gerchberg–Saxton algorithm and spatial multiplexing to segment images and projection surfaces. Segmented element images are processed to create multiple phase masks, which are then stitched for image reconstruction. Experimental results indicated that the proposed method enabled effective magnification under different segmentation methods. This method allows the enlargement of holographic images without using additional lenses, thus enabling effective magnification to be achieved with a limited setup. Reconstruction results indicate that the proposed method can produce a magnification of up to 16 × .

Physics-Based Efficient Full Projector Compensation Using Only Natural Images.

Achieving practical full projector compensation requires the projection display to adapt quickly to textured projection surfaces and unexpected movements without interrupting the display procedure. A possible solution to achieve this involves using a projector and an RGB camera and correcting both color and geometry by directly capturing and analyzing the projected natural image content, without the need for additional patterns. In this study, we approach full projector compensation as a numerical optimization problem and present a physics-based framework that can handle both geometric calibration and radiometric compensation for a Projector-camera system (Procams), using only a few sampling natural images. Within the framework, we decouple and estimate the Procams' factors, such as the response function of the projector, the correspondence between the projector and camera, and the reflectance of projection surfaces. This approach provides an interpretable and flexible solution to adapt to the changes in geometry and reflectance caused by movements. Benefitting from the physics-based scheme, our method guarantees both accurate color calculation and efficient movement and reflectance estimation. Our experimental results demonstrate that our method surpasses other state-of-the-art end-to-end full projector compensation methods, with superior image quality, reduced computational time, lower memory consumption, greater geometric accuracy, and a more compact network architecture.

Generation Mechanism of Anisotropy in Mechanical Properties of WE43 Fabricated by Laser Powder Bed Fusion.

At present, no consensus has been reached on the generation mechanism of anisotropy in materials fabricated by laser powder bed fusion (LPBF), and most attention has been focused on crystallographic texture. In this paper, an analysis and test were carried out on the hardness, defect distribution, residual stress distribution, and microstructure of WE43 magnesium alloy fabricated by LPBF. The results indicate that LPBF WE43 exhibits obvious anisotropy-the hardness HV of X-Z surface (129.9 HV on average) and that of Y-Z surface (130.7 HV on average) are about 33.5% higher than that of X-Y surface (97.6 HV on average), and the endurable load is smaller in the stacking direction Z compared to the X and Y directions. The factors contributing more to the anisotropy are listed as follows in sequence. Firstly, the defect area of the X-Y projection surface is about 13.2% larger than that of the other two surfaces, so this surface shows greatly reduced mechanical properties due to the exponential relationship between the material strength and the number of defects. Secondly, for laser scanning in each layer/time, the residual stress accumulation in the Z direction is higher than that in the X and Y directions, which may directly reduce the mechanical properties of the material. Finally, more fine grains are distributed in X-Z and Y-Z surfaces when comparing them with those in an X-Y surface, and this fine-grain strengthening mechanism also contributes to the anisotropy. After T5 aging heat treatment (250 °C/16 h), a stronger crystallographic texture is formed in the <0001> direction, with the orientation density index increasing from 10.92 to 21.38, and the anisotropy disappearing. This is mainly caused by the enhancement effect of the texture in the <0001> direction on the mechanical properties in the Z direction cancelling out the weakening effect of the defects in the X-Y surface in the Z direction.

Quantitative study of the ossification centers of the body of sphenoid bone in the human fetus

The aim of the present study was to examine the growth dynamics of the two ossification centers of the body of sphenoid bone in the human fetus, based on their linear, planar and volumetric parameters. The examinations were carried out on 37 human fetuses of both sexes aged 18–30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, we evaluated the size of the presphenoid and postsphenoid ossification centers. The presphenoid ossification center grew proportionately in sagittal diameter, projection surface area and volume, and logarithmically in transverse diameter. The postsphenoid ossification center increased logarithmically in sagittal diameter, transverse diameter and projection surface area, while its volumetric growth followed proportionately. The numerical findings of the presphenoid and postsphenoid ossification centers may be considered age-specific reference values of potential relevance in monitoring the normal fetal growth and screening for congenital disorders in the fetus. The obtained results may contribute to a better understanding of the growing fetal skeleton, bringing new numerical information regarding its diagnosis and development.

‘Modern talking’: Narratives of agile by German public sector employees

Despite growing interest, we lack a clear understanding of how the arguably ambiguous phenomenon of agile is perceived in government practice. This study aims to alleviate this puzzle by investigating how managers and employees in German public sector organisations make sense of agile as a spreading management fashion in the form of narratives. This is important because narratives function as innovation carriers that ultimately influence the manifestations of the concept in organisations. Based on a multi-case study of 31 interviews and 24 responses to a qualitative online survey conducted in 2021 and 2022, we provide insights into what public sector managers, employees and consultants understand (and, more importantly, do not understand) as agile and how they weave it into their existing reality of bureaucratic organisations. We uncover three meta-narratives of agile government, which we label ‘renew’, ‘complement’ and ‘integrate’. In particular, the meta-narratives differ in their positioning of how agile interacts with the characteristics of bureaucratic organisations. Importantly, we also show that agile as a management fad serves as a projection surface for what actors want from a modern and digital organisation. Thus, the vocabulary of agile government within the narratives is inherently linked to other diffusing phenomena such as new work or digitalisation.

A novel shadow calculation approach based on multithreaded parallel computing

Solar radiation significantly affects the thermal processes of buildings; thus, various building energy modeling programs have established corresponding shadow calculation modules. However, the large number of projection surfaces in a building requires extensive calculations, making it difficult to rapidly analyze the building shadow while ensuring hourly calculations. This study proposes an accelerated calculation framework for building shadows based on multithreaded parallel computing for an accurate building energy consumption analysis. Based on the basic principle of shadow projection calculation, the embedded, integrated development of a shadow calculation module is proposed, and a full-performance simulation platform kernel based on a multithreaded structure is constructed. Results show that the multithreaded shadow calculation framework can significantly shorten the calculation time. Based on case studies, a typical complex single building’s shadow calculation speed can be increased by nearly 2.4 times, whereas for city-scale building shadow simulations, it is only 5.4% of the original duration.

Research on Optimization of University Classroom Lighting Environment Based on Computer Simulation

In order to improve the comfort of classroom users and improve the lighting environment of university classrooms, this paper puts forward different optimization schemes based on computer simulation. Dialux, a lighting environment design software, is used to numerically simulate the lighting environment of university classrooms. The classroom lighting scheme is optimized and different solutions are proposed. Through computer simulation, the effect of lighting is compared and analyzed, in order to find the most beneficial scheme for students’ mental health, which provides the basis for intelligent control of classroom lighting. The results show that the average illuminance decreases with the increase of suspension height, and the illuminance uniformity increases first and then decreases with the increase of suspension height. The solution of adjusting the projection direction and surface reflectivity of lamps is not suitable, and upgrading the type of lamps can solve the lighting environment problems and control glare. Increasing the number of lamps and adjusting the arrangement of lamps can improve the lighting environment, increase the average value but reduce the uniformity, but lead to a significant increase in energy consumption. Intelligent control based on computer simulation can solve the coordination problem of energy consumption and lighting effect. Through comparative analysis of the effects of different schemes on the classroom lighting environment in colleges and universities based on computer simulation, this paper provides data support for the selection of improved schemes, which is conducive to the selection of more suitable intelligent lighting control schemes, to ensure students’ mental health and work efficiency, and has certain reference significance for creating a healthy and comfortable classroom lighting environment.

Bakom den leende masken

&#x0D; Theme: Motherhood and Mothering. Ill. ©Stina Wirsén&#x0D; Behind the Pretty Mask: Vulnerable Mothering in Contemporary Picturebooks about Surrogacy and Illness&#x0D; Children and adults, the dual audience of picturebooks, are joined in the act of reading aloud. For many parents, reading to their child constitutes one of the basic, intimate care practices of mothering (Rich; Holm). In this study, we examine picturebooks about surrogacy and about mothering parents who are mentally or physically ill, published in Sweden in the period between 2010 and 2022. Both types of books depict a vulnerability in relation to parenthood, motherhood and mothering and are often autobiographical and niche- or self-published. With an analytical approach grounded in critical theories of adult agency in children’s literature (Rose; Nodelman; Beauvais), we find that both picturebooks about surrogacy and illness communicate straightforward and often sentimental messages to the child reader, whereas more complex and possibly problematic adult desires and needs can be detected on the level of the adult address. Through the projected child perspective (Rhedin), our material offers the vulnerable adult reader representation and recognition in relation to a motherhood/mothering that is not unequivocally considered sufficient or legitimate. The traditional aesthetics and pedagogical use-value of the picturebook as well as the positive maternal associations to reading aloud, are essential in this legitimization process. Meanwhile, the implied child reader functions as a projection surface for adult wishes of normalcy and happy endings. Although hidden behind adult projections, it is this “mighty” child (Beauvais) who ultimately has the power to acknowledge and justify the parents in an impending future which reaches beyond the control of both adult writer and implied adult reader.

Quantitative anatomy of the extensor digiti minimi muscle in the growing human fetus.

Introduction Age-specific reference intervals for the extensor digiti minimi muscle (EDMM) in the human fetus may be relevant in the detailed evaluation of the musculoskeletal systems with potential relevant aspects for surgical treatment. The aim of the study was to examine the age-specific reference intervals and growth dynamics of the EDMM in relation to its length, width, projection surface area and volume. Material and methods The examined material included 70 human formalin-fixed fetuses of both sexes (37♀, 33♂) aged from 17 to 29 weeks. With the use of anatomical dissection every EDMM was visualized, recorded in a form of JPG formats and analyzed by the digital image analysis system and statistical methods. Results No variability of the EDMM was found. All the morphometric parameters of the EDMM revealed neither sex nor laterality differences. With fetal age most linear parameters of the EDMM concerning its examined lengths and widths increased in accordance with natural logarithmic functions. The only two exceptions to this referred to the belly width of EDMM measured at its mid-length and the tendon width of EDMM measured proximal to the extensor retinaculum of wrist, which both followed square root functions. The projection surface areas of the EDMM followed natural logarithmic functions, while the volumetric growth of the EDMM was proportionate to fetal age. Conclusions The variability of the EDMM in the human fetus is minimal. The morphometric data of the EDMM represents age-specific reference intervals of clinical significance. Morphometric parameters of the EDMM reveal neither sex nor laterality differences. The EDMM displays three different growth dynamics: from gradual growth deceleration according to both natural logarithmic functions (total length of the muscle and its tendons, belly length, tendon lengths, belly width at its origin, tendon width at its insertion, and projection surface areas) and square root functions (belly width at its mid-length and tendon width in the pre-retinacular segment) to a proportionate growth (total volume).

Quantitative study of the popliteal fossa in the human fetus.

The popliteal fossa presents an extensive diamond-shaped topographical element on the posterior aspect of the knee. With the use of classical anatomical dissection, digital image analysis of NIS Elements AR 3.0 and statistics we morphometrically analyzed the size of the popliteal fossa in human fetuses aged 17-29 weeks of gestation. Morphometric parameters of the popliteal fossa increased logarithmically with fetal age: y = -44.421 + 24.301 × ln (Age) for length of superomedial boundary, y = -41.379 + 22.777 × ln (Age) for length of superolateral boundary, y = -39.019 + 20.981 × ln (Age) for inferomedial boundary, y = -37.547 + 20.319 × ln (Age), for length of inferolateral boundary, y = -28.915 + 15.822 × ln (Age) for transverse diameter, y = -69.790 + 38.73 × ln (Age) for vertical diameter and y = -485.631 + 240.844 × ln (Age) for projection surface area. Out of the four angles of the popliteal fossa the medial one was greatest, the inferior one the smallest, while the lateral one was somewhat smaller than the medial one and approximately three times greater than the superior one, with no difference with fetal age. In terms of morphometric parameters the popliteal fossa in the human fetus displays neither male-female nor right-left differences. In the popliteal fossa, growth patterns of its four boundaries, vertical and transverse diameters, and projection surface area all follow natural logarithmic functions. All the morphometric data is considered age-specific reference intervals, which may be conducive in the diagnostics of congenital abnormalities in the human fetus.

ViComp: Video Compensation for Projector-Camera Systems.

Projector video compensation aims to cancel the geometric and photometric distortions caused by non-ideal projection surfaces and environments when projecting videos. Most existing projector compensation methods start by projecting and capturing a set of sampling images, followed by an offline compensation model training step. Thus, abundant user effort is required before the users can watch the video. Moreover, the sampling images have little prior knowledge of the video content and may lead to suboptimal results. To address these issues, this paper builds a video compensation system that can online adapt the compensation parameters. Our approach consists of five threads and can perform compensation, projection, capturing, and short-term and long-term model updates in parallel. Due to the parallel mechanism, rather than projecting and capturing hundreds of sampling images and training the model offline, we can directly use the projected and captured video frames for model updates on the fly. To quickly apply to the new environment, we introduce a deep learning-based compensation model that integrates a fixed transformer-based method and a novel CNN-based network. Moreover, for fast convergence and to reduce error accumulation during fine-tuning, we present a strategy that cooperates with short-term and long-term memory model updates. Experiments show that it significantly outperforms state-of-the-art baselines.

Quantitative anatomy of the primary ossification center of the squamous part of temporal bone in the human fetus

Detailed numerical data about the development of primary ossification centers in human fetuses may influence both better evaluation and early detection of skeletal dysplasias, which are associated with delayed development and mineralization of ossification centers. To the best of our knowledge, this is the first report in the medical literature to morphometrically analyze the primary ossification center of the squamous part of temporal bone in human fetuses based on computed tomography imaging. The present study offers a precise quantitative foundation for ossification of the squamous part of temporal bone that may contribute to enhanced prenatal care and improved outcomes for fetuses with inherited cranial defects and skeletodysplasias. The examinations were carried out on 37 human fetuses of both sexes (16 males and 21 females) aged 18–30 weeks of gestation, which had been preserved in 10% neutral formalin solution. Using CT, digital image analysis software, 3D reconstruction and statistical methods, the size of the primary ossification center of the squamous part of temporal bone was evaluated. With neither sex nor laterality differences, the best-fit growth patterns for the primary ossification center of the squamous part of temporal bone was modelled by the linear function: y = −0.7270 + 0.7682 × age ± 1.256 for its vertical diameter, and the four-degree polynomial functions: y = 5.434 + 0.000019 × (age)4 ± 1.617 for its sagittal diameter, y = −4.086 + 0.00029 × (age)4 ± 2.230 for its projection surface area and y = −25.213 + 0.0004 × (age)4 ± 3.563 for its volume. The CT-based numerical data and growth patterns of the primary ossification center of the squamous part of temporal bone may serve as age-specific normative intervals of relevance for gynecologists, obstetricians, pediatricians and radiologists during screening ultrasound scans of fetuses. Our findings for the growing primary ossification center of the squamous part of temporal bone may be conducive in daily clinical practice, while ultrasonically monitoring normal fetal growth and screening for inherited cranial faults and skeletodysplasias.

Visual perception-oriented quality assessment for high dynamic range stereoscopic omnidirectional video system

High dynamic range stereoscopic omnidirectional video (HSOV) system provides users with an immersive visual experience, but the distortions generated in the process of visual content generation, coding, and visualization also brings challenges to visual quality assessment. This paper proposes a visual perception-oriented quality metric for HSOV system. Considering the computational efficiency, for frames within each second, several key frames are selected so that features reflecting distortions can be extracted from the viewports and equi-angular cubemap (EAC) projection surfaces of these frames. In viewport feature extraction module, the sum and difference maps of the left and right views of the key frames are used to simulate the binocular perception. Considering that distortions will affect the structure, color and statistical properties of the image, the gradient, local binary pattern and statistical features are extracted, respectively. To reduce projection distortion, EAC projection is used to instead of other projections normally used in quality assessment, and the Sigma domain feature extraction and color feature extraction are performed on EAC projection map. In temporal feature extraction module, wavelet decomposition is used to perform temporal domain bandpass filtering on partial continuous frames to calculate the naturalness features. Finally, the above features of the frames at different scales are pooled through random forest model to predicate the quality score of HSOV. Experimental results on the NBU-HSOVD dataset show that the proposed metric is superior to some blind image/video quality assessment metrics and has higher consistency with the human visual perception.

Quantitative study of the primary ossification centre of the parietal bone in the human fetus.

Detailed morphometric data concentrating on the development of primary ossification centres in human fetuses is critical for the early detection of developmental defects. Thus, an understanding of the growth and development of the parietal bone is crucial in assessing both the normal and pathological development of the calvaria. The size of the parietal primary ossification centre in 37 spontaneously aborted human fetuses of both sexes (16 males and 21 females) aged 18-30 weeks was studied by means of computed tomography, digital-image analysis and statistics. The numerical data of the parietal primary ossification centre in the human fetus displays neither sex nor laterality differences. With relation to fetal age in weeks, the parietal primary ossification centre grew in sagittal diameter according to the quadratic function: y = 16.322 + 0.0347 × (age)² ± 1.323 (R² = 0.96), in projection surface area according to the cubic function: y = 284.1895 + 0.051 × × (age)³ ± 0.490, while in both coronal diameter and volume according to the quartic functions: y = 21.746 + 0.000025 × (age)⁴ ± 1.256 and y = 296.984 + + 0.001 × (age)⁴, respectively. The obtained morphometric data of the parietal primary ossification centre may be considered age-specific references, and so may contribute to the estimation of gestational ages and be useful in the diagnostics of congenital cranial defects.

Climate change-induced urban heat Island trend projection and land surface temperature: A case study of Thailand's Bangkok metropolitan

This research projects future climate change-induced urban heat island (UHI) trends (2022–2099) using three dynamically downscaled regional climate models (RCM1 – RCM3) under two representative concentration pathways: RCP4.5 and 8.5. RCP 4.5 is a moderate scenario in which emissions peak around 2040 and then decline, while RCP 8.5 is the highest baseline emissions scenario in which emissions continue to rise throughout the twenty-first century. An RCM is a numerical climate prediction model forced by specified lateral and ocean conditions from observation-based dataset that simulates atmospheric and land surface processes. In the study, the RCMs are based on three respective global climate models: ICHEC-EC-EARTH, MPI-M-MPI-ESM-MR and NOAA-GFDL-GFDL-ESM2M. The study area is Thailand's capital Bangkok, and the UHI trends are determined by the Mann-Kendall trends and Sen's slope estimates of 13 future temperature-based extreme climate indexes, consisting of nine warm extreme indexes and four cold extreme indexes. The findings reveal that the majority of the warm extreme indexes are trending upward, while most of the cold indexes exhibit a downward trend. In essence, the Bangkok metropolitan area highly likely experiences warmer temperatures in the future, contributing to higher land surface temperature and UHI intensity.

Study on Stable Phase Equilibria of Quinary System LiBr–NaBr–KBr–MgBr2–H2O at 298.15 K

According to the composition characteristics of mineral elements in underground brine in the Sichuan basin of China, the complete phase equilibria and phase diagram of the quinary system LiBr–NaBr–KBr–MgBr2–H2O were studied at 298.15 K. Using the experimentally determined solubilities and equilibrium solids, the spatial stereo phase diagram of the quinary system, the dry base projection phase diagrams of the saturated surfaces of the four salts MgBr2·6H2O, KBr, LiBr·2H2O, and NaBr·2H2O, and the corresponding water content diagrams were plotted, respectively. The experimental results show that at 298.15 K, in addition to the four original components, the anhydrous salt NaBr and the double salt KBr·MgBr2·6H2O are formed. The phase diagram of the quinary system at 298.15 K contains 10 univariate curves, three invariant points, and six equilibrium solid-phase crystallization regions (KBr crystallization region, NaBr crystallization region, NaBr·2H2O crystallization region, MgBr2·6H2O crystallization region, LiBr·2H2O crystallization region, KBr·MgBr2·6H2O crystallization region). When MgBr2·6H2O or KBr is saturated, LiBr has a strong salting-out effect on KBr, NaBr, or MgBr2 and NaBr, while when LiBr·2H2O is saturated, MgBr2 has a salting-out effect on KBr and NaBr. All four saturated projection surfaces have MgBr2·6H2O, and NaBr is generated. These phase equilibrium data can provide a theoretical basis to guide underground brine mining and extract useful components.

Shelter news: affordance, place and proximity in news media representations of civil defence artefacts

ABSTRACT Sweden has a system of 64,000 air-raid shelters. Built over a period of 80 years and providing protection for about 70% of the population, the shelters have taken on a special role in the country’s public setting. Their omnipresence has made them sociocultural symbols in Swedish society. However, while the origins of air-raid-shelter symbolism are well researched within historical studies, little is known about the role shelters play in media settings today. While the air-raid shelters originate from a highly militarized past, contemporary mediations do not necessarily follow this heritage. In this cross-disciplinary article, the role of air-raid shelters in Swedish news-media reporting in 2015 to 2018 is studied in an effort to understand how sociocultural interpretations of air-raid shelters are produced and mediated in news-media settings, and how such interpretations are spread and reproduced throughout the media sphere. Inspired by research stemming from historical studies, STS (Science and Technology Studies), and media and communication, the article shows that news-media reporting on air-raid shelters is highly flexible, yet limited to a set of afforded interpretations that sometimes exist parallel to each other. The article also discusses how journalists’ and commentators’ use of ‘proximity’ and ‘place’ interplays with the existence and abundance of shelters in local settings. In sum, the findings highlights the air-raid shelters function as a projection surface for moral debates in public media, but also that abundance of shelters in urban settings do not guarantee that discussions will concern air-raid shelters actual function as a risk reducing technology.

Improving Effectiveness of Basketball Free Throws through the Implementation of Technologies in the Technical Training Process

The aim of the study was to implement a specific training program to improve basketball free throws by using an innovative system called “system and technical device designed for motor learning process in the field of sports science and physical education with direct applicability in basketball specific training-free throw improvement”, as well as to evaluate the level of free throw effectiveness. We also aimed to highlight the differences in progress between the experimental and control groups for three age categories U14, U16, and U18 male juniors. The system and the device for detecting the ideal trajectory of the ball were provided by a high-speed video camera which captured the images and projected them in real-time onto a projection surface that was placed in front of, or to the side of the athlete, depending on the subject’s preference, provided that this projection surface is in the performer’s field of vision. The research took place from 5 April to 10 July 2021 and phased as follows: initial testing, implementation of the experimental 12-week free-throw training program (one individualized training session per week lasting 120 min), and final testing. The study included 360 subjects aged 13–14 years, who were grouped according to gender and team sport played. The evaluation was done by three tests: the FRB test (standardized test), the Shoot-Run test, and the 10 experimental throws test. The results of the study in all three motor tests showed that by implementing the innovative system that was designed for motor learning, the effectiveness of free throw shooting improved significantly in the players of the experimental groups in all age groups (U14, U16, U18), thus evidencing a positive, upward dynamic in relation to the increasing age category. In all three motor tests, the progress of the experimental groups was superior to the control groups as a result of the implementation of the experimental exercise program using the innovative system and device that was designed to improve free throws. The results of the study highlighted the effectiveness and opportunity of the implementation of innovative technologies in the process of training and evaluation of basketball specific free throws.

Noncontact Detection Method for Food Texture Assessment Based on Air Puff Combined With Structured Light Imaging

Given the shortcomings of subjectivity and destructiveness associated with traditional methods of measuring food texture parameters (such as fruit firmness and meat tenderness) when using a texture meter, a non-contact measurement method utilizing an Air-puff combined with Structured Light Imaging (ASLI) was proposed in this study. First, the finite element simulation method was used to simulate the airflow impact model and optimize the ranges of the angle and distance parameters. The detection device was then developed, and binocular 3D phenotype acquisition and 3D feature extraction algorithms were investigated. Denoising, point cloud segmentation, greedy projection triangulation, Delaunay triangulation, and surface fitting algorithms were used to process the point cloud, and concave parameters such as depth, mapping area, surface area, and volume of the concave area on the beef surface were obtained. Finally, four typical samples with different meat (beef and chicken) and fruit (kiwifruit and peach) parameters were tested. Five machine learning methods were used to model and analyze the correlation among texture parameters. The results revealed that the model established by the ensemble learning modeling method with extracted concave parameters possessed the highest accuracy. The prediction accuracy of the shear force values of the beef and chicken samples were 0.92 and 0.91. The accuracy of meat and fruit grading was 0.942 and 1.0. Therefore, the non-contact detection method proposed in this study to determine food texture characteristics based on airflow can be used to replace the traditional texture analyzer in food engineering and exhibits good application potential.