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Mechanism of sand mold warping was systematically analyzed through experiments and numerical calculations. The results show that the asymmetric thermal stress is the main factor which leads to warping because of the temperature difference in the sand mold during printing. Then, composite powders with silica particle and thermosetting phenolic resin (TSPF) were developed, and they show better warping resistance below 0.15 J/mm2 compared with those of traditional coated sand. In addition, the thermoplastic phenolic resin (TPPF) was added to further reduce the thermal stress due to its cyclic solid-liquid phase change. When the TPPF content reaches 50% or more, the warping of no longer occurs, and warping ratio is reduced by an order of magnitude. However, when the TPPF content is 100%, the sand mold warps in reverse due to the lack of supporting skeleton. This work provides a new way to restrain the warping of casting sand mold. [ABSTRACT FROM AUTHOR]

The curing distortion is a critical determinant of the quality of integrally manufactured composite structures, playing a pivotal role in the design and fabrication of composite. This paper presents two simplified methods in predicting the curing distortion for large-scale composite aircraft structures manufactured through the autoclave process. Firstly, the refined finite element models of the two simplified methods were developed. Then, it was utilized to predict the curing distortion of Ω-shaped composite laminates. The comparative study between the experimental data and numerical results shows that the proposed second simplified method balanced the prediction accuracy and efficiency, which is urgently needed in practice. Finally, using the second simplified method, predictions were conducted for the curing distortion of practical large-scale composite skin structures. The results were in good agreement with the corresponding experiments. This study provides a new solution for the rapid iterative design of large-scale composite structures, as well as the efficient design of frame molds for their manufacturing. [ABSTRACT FROM AUTHOR]

Colour is used increasingly often as quantitative indicator of combined continuous features such as temperature and humidity on geographical maps, or deformity on two axes in medical diagnosis. As such, generating flexible bivariate legends with particularly tough colour constraints for specific combinations of the variables has come to the forefront. The paper presents a systematic method of generating bivariate legends by first selecting a convenient colour subspace and then adjusting it through image processing techniques. The proposed method can generate a wide variety of legends with smart choices of parameters but remains simple enough to be worthy of consideration by specialists (in various fields) whose representations may benefit by becoming better intelligible. These legends can be used for pseudo-colouring of maps, diagrams, and many other images and graphical representations. An example is also provided for a comprehensive colouring to be used in the medical diagnosis of spine deformity. [ABSTRACT FROM AUTHOR]

Real-time rendering has been embracing ever-demanding effects, such as ray tracing. However, rendering such effects in high resolution and high frame rate remains challenging. Frame extrapolation methods, which do not introduce additional latency as opposed to frame interpolation methods such as DLSS 3 and FSR 3, boost the frame rate by generating future frames based on previous frames. However, it is a more challenging task because of the lack of information in the disocclusion regions and complex future motions, and recent methods also have a high engine integration cost due to requiring G-buffers as input. We propose a G-buffer free frame extrapolation method, GFFE, with a novel heuristic framework and an efficient neural network, to plausibly generate new frames in real time without introducing additional latency. We analyze the motion of dynamic fragments and different types of disocclusions, and design the corresponding modules of the extrapolation block to handle them. After that, a light-weight shading correction network is used to correct shading and improve overall quality. GFFE achieves comparable or better results than previous interpolation and G-buffer dependent extrapolation methods, with more efficient performance and easier integration. [ABSTRACT FROM AUTHOR]

This study is based on a theory for analyzing non-uniform torsion in thin-walled beams made of homogeneous elastic material with arbitrary cross-sections by incorporating the effect of the shear deformation of a cross-section. Utilizing the Finite Element Method (FEM), the proposed numerical approach addresses non-uniform torsion by breaking down a 3D analysis into 2D cross-sectional and 1D modeling components. Initially, the geometric constants of the cross-section were computed using a 9-node isoparametric element in 2D FEM. Subsequently, a 1D FEM employing a linear isoparametric element calculated the twist angle, torsion warping parameters, and stress results. The stress field was determined through a local analysis of the 2D cross-section. Notably, the 2D FEM component aligns with contemporary trends in commercial software, thereby bolstering the potential and practical applicability of the proposed numerical approach. Its verification and validation through numerical analyses using MATLAB underscore the efficacy and reliability of the method in analyzing non-uniform torsion behavior in structural design, particularly under diverse boundary conditions.

Conventional beam elements ignoring distortion may overestimate the lateral resistance of frames and curved beams made of monosymmetric I-sections. This paper introduces two new distortional modes represented by mechanical couples relative to twisting and shearing of the two flanges that are opposite in directions but unequal in magnitudes. A straight beam element with nine degrees of freedom (DOFs) per node, including the conventional three translations, three rotations, warping and the new two distortions, is newly derived. This allows all the DOFs of the connected elements at a common joint to be easily transformed to the global coordinates for stiffness assembly. As a result, the warping–distortion compatibility problem that occurs in frames and curved beams is resolved. In the numerical examples, the results produced by the present beam element is demonstrated to agree excellently with the shell-element solutions for the lateral-distortional deformation of the angled frame and curved beam. It is observed that the cross-sectional distortion effect becomes extremely significant for angled frames of short unbraced length and for curved beams of high curvature. [ABSTRACT FROM AUTHOR]

Background: The use of 3D-printing in medicine requires a context-specific quality assurance program to ensure patient safety. The process of medical 3D-printing involves several steps, each of which might be prone to its own set of errors. The segmentation error (SegE), the digital editing error (DEE) and the printing error (PrE) are the most important partial errors. Approaches to evaluate these have not yet been implemented in a joint concept. Consequently, information on the stability of the overall process is often lacking and possible process optimizations are difficult to implement. In this study, SegE, DEE, and PrE are evaluated individually, and error propagation is used to examine the cumulative effect of the partial errors. Methods: The partial errors were analyzed employing surface deviation analyses. The effects of slice thickness, kernel, threshold, software and printers were investigated. The total error was calculated as the sum of SegE, DEE and PrE. Results: The higher the threshold value was chosen, the smaller were the segmentation results. The deviation values varied more when the CT slices were thicker and when the threshold was more distant from a value of around -400 HU. Bone kernel-based segmentations were prone to artifact formation. The relative reduction in STL file size [as a proy for model complexity] was greater for higher levels of smoothing and thinner slice thickness of the DICOM datasets. The slice thickness had a minor effect on the surface deviation caused by smoothing, but it was affected by the level of smoothing. The PrE was mainly influenced by the adhesion of the printed part to the build plate. Based on the experiments, the total error was calculated for an optimal and a worst-case parameter configuration. Deviations of 0.0093 mm ± 0.2265 mm and 0.3494 mm ± 0.8001 mm were calculated for the total error. Conclusions: Various parameters affecting geometric deviations in medical 3D-printing were analyzed. Especially, soft reconstruction kernels seem to be advantageous for segmentation. The concept of error propagation can contribute to a better understanding of the process specific errors and enable future analytical approaches to calculate the total error based on process parameters. [ABSTRACT FROM AUTHOR]

In this paper, the accurate free vibration characteristics of thin-walled box beam are discussed and the kinematic model is established by using fine shear deformation theory. The model adopts the in-plane and out-of-plane displacement fields including extension, torsion, warping and distortion, as well as the transverse shear due to bending and warping due to torsion. One-dimensional high-order beam theory is applied to the dynamic solution of thin-walled box beam, and the analytical solution of high free vibration modes of multi-deformation coupled modes under different boundary conditions is derived. The results show that warping, distortion and shear deformation play an important role in the free vibration characteristics of thin-walled box beam, and the validity of the model is verified. In addition, finite element software (ANSYS) is used for finite element simulation. The application of vibration mode in the structure design of thin-walled box beam is summarized, especially in the case of higher natural frequency. The calculation method is in good agreement with the finite element results. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office 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.)

Thin-walled channel beams such as cold-formed steel purlins are primarily used to withstand wind forces in the roofing and walling systems of buildings. Traditionally, these types of members are usually designed for bending moments, with the effects of torsion ignored. However, the loading on thin-walled channels can be much more complicated than simple bending actions. Because of the position of the shear centre outside the section, channels can undergo bending and torsion when subjected to vertical load on the top flange. The applied torsion may cause significant stresses in the channel, which may need to be accounted for in design. There appears to be no research on quantifying the effects of torsion on thin-walled channels subjected to a uniformly distributed load acting on the top flange. In this paper, a theoretical solution is derived for calculating the longitudinal stresses in thin-walled channels subjected to torsion caused by a uniformly distributed load acting on the top flange. The theory is validated by modelling the channels in a finite-element analysis. The theoretical results include calculations of the twist rotation, bimoment, sectorial coordinate and longitudinal stresses, while the results from the finite-element analysis include the twist rotation and longitudinal stresses. The results show that the longitudinal stresses caused by torsion can significantly exceed those caused by the bending moment. Practical advice is also given for engineers on how to minimize torsion in cold-formed steel purlins. [ABSTRACT FROM AUTHOR]

This study presents a warping included mixed finite element formulation for the static and stress analyses of functionally graded (FG) exact curved beams. Another distinctive feature of this study is to present the range of geometric and material parameters where the first-order shear deformation theory lacks necessary precision. The constitutive equations are derived from the 3D elasticity theory of an elastic continuum. The couple effects are considered in addition to the variations of FG material constituents through the transverse/axial directions. The mixed finite element formulation is enhanced by the cross-sectional warping deformations over a displacement-type finite element formulation. The two-noded curved mixed finite elements with 12 degrees of freedom at per node are derived over exact curvature and length. Satisfactory results are obtained for the static responses and stresses of axially FG-sandwich and transversely FG exact curved beams with power-law dependence compared to the 3D behavior of brick finite elements. Finally, the influences of ellipticity, width to thickness ratio, FG material constituents, and material gradient index on the static response of FG exact curved beams are investigated. [ABSTRACT FROM AUTHOR]

We introduce a deep learning-driven framework for creating an adaptably applicable importance map (A2R-Map) that can be integrated with existing image and video retargeting operators. A conventional retargeting algorithm uses a heuristic approach to seek an off-the-self algorithm used into their retargeting system. The extracted importance map of the image does not match the characteristics of the input image; therefore, it affects the retargeting results and limits the performance of the retargeting method. Our designed framework attempts to minimize the artifacts/distortions caused by inappropriate energy, e.g., the shrunk phenomenon in warping-based results and carving-through-object distortion in the seam carving-based approach. Our proposed framework focuses on capturing sensitive distortion regions and activating their energy to solve this challenge. We verify the effectiveness of our proposed scheme by plugging it in three typical retargeting methods: seam carving-based, warping-based for image, and video retargeting. Extensive experiments and evaluations are conducted on two widely used databases. On the one hand, A2R-Map significantly reduces the time of importance map generation in retargeting systems to ∼ 9 times compared to the baseline saliency map. On the other hand, our A2R-Map achieves improvement over the baseline methods with an average of 11% and 9% in terms of image and video quality, respectively. The experimental results and evaluations demonstrate that our strategy for A2R-Map substantially outperforms the previous works and significantly boosts the visual quality of video/image retargeting. [ABSTRACT FROM AUTHOR]

Together with axial and flexural actions, modern-designed reinforced-concrete walls can also be subjected to torsion during rare loading events, such as large-magnitude earthquakes or strong winds. For certain widely used nonplanar open cross-section geometries, this torque is resisted primarily through warping. In some cases, the longitudinal stresses caused by torsional warping can be of the same order of magnitude as those caused by flexure, which postulates a reduction of the in-plane bending moment capacity of the section. This study explores the reduction of bending moment capacity of open reinforced-concrete U-shaped core walls due to the simultaneous application of flexural, axial, and torsional loading. Initial investigations focused on strain gradients through the wall segments of reinforced-concrete U-shaped walls. Using a refined data set from a recent experimental campaign, the commonly assumed linear strain gradient used in the design of reinforced-concrete walls is challenged. Numerical methods that intrinsically rely on the observed strain gradients are then employed to compute, for a range of torque-to-bending-moment ratios, the ultimate bending moment and torque capacities from combined loading scenarios. The numerical results corroborate existing experimental results, indicating a significant reduction (almost half) in ultimate bending moment capacity when a torque equal to approximately 20% of imposed bending is applied. Interaction diagrams between the ultimate torque and bending moment show that it is possible to derive a simple relationship between the two for the purposes of structural design. These results can help formulate guidelines for future international building codes, which in their current form cannot account for the design of open sections governed by warping torsion. [ABSTRACT FROM AUTHOR]

Copyright of China Textile Leader is the property of China Textile Information Center 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.)

The clonal materials of Tectona grandis L. f. in fast-growing plantations exhibit faster growth than the seminal materials. Therefore, it is necessary to investigate the differences in wood drying to ensure the quality and yield of the final product. This study evaluated the outdoor drying behavior of three genotypes of teak lumber. Two clonal genotypes (G1 and G2) and one of seminal origin (G3) were assessed. Boards measuring 30 × 150 × 1000 mm (thickness × width × length) were produced from the basal logs. The average moisture content (79.3, 64.9, and 60,1%), final moisture content (10.8, 9.8, and 11.6%), and mean drying rate (1.2, 0.97, and 0.85%.day-1) were observed in the wood from genotypes G1, G2 and G3, respectively. The clonal material crooked and bowed below 5 mm.m-1, which is considered the tolerance limit for both warpings. The seminal material had a greater incidence of splitting. The clonal genotypes G1 and G2 had similar qualities and presented higher drying rates, final moisture contents below 11% and a lower incidence of defects, especially splitting, compared to the naturally seeded material.

One of the main objectives of weaving production is the production of high quality fabrics and the search for ways to increase the productivity of weaving machines in order to improve the economic performance and competitiveness of the enterprise. In the production conditions of RUPTE "Orsha Linenmill" weaving machines Picanol OptiMax 190 are installed for the production of a range of household fabrics from low linear density yarn, most of which are exported. To ensure the quality of pure linen fine fabrics and the production of fine yarn, long flax fibre No. 11–14 and above is required. However, due to a number of reasons, the quality and quantity of incoming domestic raw materials cannot guarantee stable technological efficiency of production preparation and weaving processes, which is provided by the uniformity of flax and flax-containing yarn and its tensile properties. The aim of the research is to reduce warp breakage in weaving by determining rational production parameters on the loom and the choice of the sizing agent in order to increase the productivity of the loom in the production of linen fabrics with low surface density. In the article the properties of wet spinning yarn of 30 tex linear density made of long linen fibre are studied, the features of Karl Mayer SMR-SP-10-1800/800 SMR-SP-10-1800/800 sizing machine and Picanol OptiMax 190 rapier weaving machine are studied, the selection of modern sizing agent was made in order to increase machine productivity and reduce warp breakage during weaving of the most elite and marketable article – linen fabric with surface density of 120 g/m2. The changes in the technology made it possible to reduce the equipment downtime by reducing the number of warp breaks from 0.95 to 0.76 breaks per 1 running meter of fabric, to increase the coefficient of utilisation and to increase the annual volume of fabrics produced.

AbstractThe current research presents a dynamically coupled mathematical model considering the energy method and employing the classical Ritz-approximation method for a thin-walled anisotropic tapered rotating box beam. The novelty of this work lies in presenting the effect of circumferentially uniform stiffness (CUS) ply layup to investigate the reverberations of not considering bending-shear couplings toward vibration behavior. The current model is formulated by considering transverse shear and cross-sectional warping of order primary and secondary. The repercussions of not including non-classical effects like Coriolis-force, centrifugal-acceleration and warping, inertial-warping is explored. Mode switching arising for change in geometry and centrifugal stiffening is presented for various ply angles and rotational speeds. [ABSTRACT FROM AUTHOR]

A variationally consistent analytical beam model that describes the theory in a Timoshenko-Vlasov level is developed based on Reissner's mixed variational theorem. Starting from a shell theory, all the field-governing equations (equilibrium and continuity) and the boundary conditions of the shell wall are derived in closed form, and the mixed method enables finding the explicit forms of the reactive stresses and sectional warpings which are evaluated progressively depending on the level of beam model to be analyzed. The stress recovery part is incorporated in the post-stage of the analysis to compute the layer-wise distribution of stresses over the beam cross-section. The present analysis is validated against numerous benchmark examples available in the literature, including beams with multi-layered strip section, thin-walled anisotropic box sections with elastic couplings, and two-cell airfoil section. The comparison study demonstrates excellent correlations with the results from detailed three-dimensional finite element analysis and other up-to-date beam approaches. Also presented are symbolically expressed stiffness coefficients and the sectional warping modes of coupled composite beams to demonstrate the strength of the proposed beam model. [ABSTRACT FROM AUTHOR]

Within the framework of linear elasticity, we show that any displacement of a straight rod is the sum of a Bernoulli–Navier displacement and two terms, one for shearing and the other for warping. Then, we load a straight rod so that bending and shear contribute the same to the rotations of the cross-section. [ABSTRACT FROM AUTHOR]

Warping not only one of the most important phenomena in steel section it is also considered as the most complicated phenomena. Ductility, bearing capacity and serviceability of steel sections may affect by increasing stress concentration of the normal stresses due to warping. In the present work, simulation of steel beam section under effect of warping is studied. Two cantilevers connected to two columns in opposite sides with a middle steel beam-column connection to create different moments on the beam to investigate the behavior of steel section under warping using building information modeling. It is found that the stress strain relationship has four groups depending on the load intensity and the angle of rotation induced due to warping. [ABSTRACT FROM AUTHOR]

The clonal materials of Tectona grandis L. f. in fast-growing plantations exhibit faster growth than the seminal materials. Therefore, it is necessary to investigate the differences in wood drying to ensure the quality and yield of the final product. This study evaluated the outdoor drying behavior of three genotypes of teak lumber. Two clonal genotypes (G1 and G2) and one of seminal origin (G3) were assessed. Boards measuring 30 × 150 × 1000 mm (thickness × width × length) were produced from the basal logs. The average moisture content (79.3, 64.9, and 60,1%), final moisture content (10.8, 9.8, and 11.6%), and mean drying rate (1.2, 0.97, and 0.85%.day-1) were observed in the wood from genotypes G1, G2 and G3, respectively. The clonal material crooked and bowed below 5 mm.m-1, which is considered the tolerance limit for both warpings. The seminal material had a greater incidence of splitting. The clonal genotypes G1 and G2 had similar qualities and presented higher drying rates, final moisture contents below 11% and a lower incidence of defects, especially splitting, compared to the naturally seeded material. [ABSTRACT FROM AUTHOR]

A problem of restrained torsion of thin-walled beams under the action of an end torque is considered. The asymptotic splitting method is applied to obtain a system of resolving equations that describes combined torsion, tension-compression, and bending of the beam. The example of typical cross sections is used to compare the resulting model with a stress-strain state in the beam, determined in the calculation using the developed model and three-dimensional numerical calculation by the finite element method. The resulting mathematical model is analyzed and its advantages are revealed and compared to the widely used Vlasov theory. It is shown that the developed model does not contain the restrictions imposed by the Vlasov theory hypotheses, such as the nondeformability of the cross-sectional contour and the absence of shear strains on the middle surface. The resulting model makes it possible in many cases to more accurately determine the emerging stress-strain state. In particular, it is shown that the developed model accounts for the presence of a boundary layer near the clamped end, which arises during torsion of angle sections and makes a significant contribution to longitudinal stresses, while the Vlasov theory does not allow for the recovery of the arising longitudinal stresses. [ABSTRACT FROM AUTHOR]

Dispersion is a representative property of low-frequency sound propagation over long distances in shallow-water waveguides, making dispersion curves valuable for geoacoustic inversion. This study focuses on estimating the geoacoustic parameters using the dispersion curves extracted from airgun sounds received in the East Siberian Sea. The seismic survey was conducted in September 2019 by the icebreaking research vessel R/V Araon, operated by the Korea Polar Research Institute. A single hydrophone was moored at the East Siberian Shelf, characterized by nearly range-independent shallow water (<70 m) with a hard bottom. In the spectrogram of the received sounds, the dispersion curves of the first two modes were clearly observed. Utilizing a combination of warping transform and wavelet synchrosqueezing transform these two modes were separated. Then, the geoacoustic parameters, such as sound speed and density in the sediment layer, were estimated by comparing the two modal curves extracted at a source-receiver distance of approximately 18.6 km with the predictions obtained by the KRAKEN normal-mode propagation model. Subsequently, the distances between the airgun and the receiver system in the 18.6 to 121.5 km range were estimated through the comparison between the measured modal curves and the model replicas predicted using the estimated geoacoustic parameters. [ABSTRACT FROM AUTHOR]

Fused filament fabrication, also known as material extrusion, is an additive manufacturing process used in many industries. Despite its widespread application, common issues like an unwanted deformation of the part to be printed during the process are rarely investigated. These failures, called warping, can be avoided by a sufficient adhesion between build surface and part. Although printing processes can last up to several days, the time dependencies and the mechanism causing adhesion are poorly understood. For this reason, the time dependence of adhesion between polylactic acid and polyamide as printing materials and different building surfaces will be investigated. The adhesion forces can change up to 60% within 20 minutes dependent on the build surface temperature. Higher build surface temperatures lead to a stronger change. These results indicate that besides mechanical adhesion other mechanisms could be involved. Adhesion measurements before and after sandblasting the build surfaces support this. For brass and borosilicate glass as build surface materials, a complete loss of adhesion was observed, whereas it did not change for Pertinax. These overall results lead to the assumption that adhesion occurs because of ionic bond onto brass surfaces and because of hydrogen bond onto borosilicate glass and Pertinax. [ABSTRACT FROM AUTHOR]

The displacement field and governing equation completely depend on the cross-section shape in the torsion of nano-bars. Due to the torsion of structure and warping of its cross-section, axial strain is created. A review of the literature demonstrates that the effect of the normal strain in the torsional analysis of nanostructures with non-circular cross-sections is ignored for the sake of simplicity and causes a computational error. While in the torsion of short nano-bars due to the great warping of the cross-section the normal strain appears and it shouldn't be ignored. Therefore, for the first time, the effect of normal strain based on the torsion of Timoshenko-Gere theory is considered in this research. In this theory, the twist rate of non-circular sections in the axial direction is not considered constant, unlike studies in the literature. The governing equation of torsional vibration is extracted using the Hamilton principle, and the nonlocal strain gradient theory is used to show the size-dependent effects. The fundamental frequency is calculated for the arbitrary cross-section shape by using Galerkin's method. The effect of parameters such as size effects, the thickness of nano-bar, mode number, and dimensions changes of cross-section versus natural frequency of nano-bar for both the Timoshenko-Gere and typical theories are investigated. Results indicate that neglecting normal strain due to warping the cross-section causes a significant error in the short nano-bars, especially at higher mode numbers. Also, a comparison is made between the obtained natural frequencies and those of the results reported in the literature. [ABSTRACT FROM AUTHOR]

Copyright of Bearing is the property of Bearing Editorial Office 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.)

How can scalable vector graphics (SVG) data of human faces be transformed to resemble specific animal faces? Since the early $20^{th}$ century, multimedia featuring animals has garnered significant attention, particularly as interest in anthropomorphic animals has grown. In this paper, we survey various anthropomorphic studies. Additionally, we develop a warping system for anthropomorphizing animal characters. Our system enables the automatic generation of anthropomorphized animal characters using SVG datasets. This dataset includes frontal and side views of 60 animal species commonly featured in animations, as well as male and female human characters. Users can create new anthropomorphized animal characters using our dataset and their vector data. Our warping system implements a continuous warping technique between animal and human facial shapes in ten stages, supported by a developed algorithm and an SVG warping program. The code of the warping system and SVG dataset are available at link: https://github.com/jenero05458/SVG_warping

Recent deep learning techniques have enabled simple methods of image editing through textual instructions; however, it remains challenging to perform specific and quantitative editing. In contrast, intuitive image editing methods that use displacement vectors often require the preservation of the original appearance after editing. This study proposes a new method for precisely editing expressions and orientations in facial images. Existing methods that rely on displacement vectors are unable to independently edit facial expressions and orientations. Our method offers separate editing capabilities by introducing multiple displacement vectors with two roles, which are used for transferring three-dimensional (3D) keypoints. These keypoints are then used in image warping to achieve stable deformations. The process involves extracting the movements of 3D keypoints with the images sampled from movies, which are then used to train a deep neural network for expression edits. In addition, the 3D rotation matrix for the keypoints is calculated to handle the change of face orientation. The edited keypoints are passed through a thin-plate spline motion model to warp an input facial image used as an identity. Our method outperforms existing facial image editing and warping methods in preserving face identity by 3.7% in terms of the structural similarity, as demonstrated by quantitative comparisons, and produces more natural results qualitatively.

When designing steel members with nonsymmetric cross sections, it is essential to consider twisting effects when performing stability checks via second-order analysis according to the ANSI/AISC 360-22. Existing line-element formulations for nonsymmetric sections are mostly derived based on thin-walled assumptions, leading to an overestimation of member strength due to the inaccurate prediction of member behavior, especially when the cross sections have moderate wall thickness. This paper proposes an efficient line-element method for second-order analysis of steel members with nonsymmetric thick-walled sections considering the warping degree of freedom (DOF) and the twisting effects along with the transverse shear deformations. Additionally, a two-dimensional (2D) finite-element cross section analysis method employing the constant strain triangle (CST) element is developed to calculate the section properties for arbitrary cross sections, including the Wagner and the shear coefficients. The proposed method is implemented in the educational structural analysis software MASTAN2 and verified through two sets of examples. [ABSTRACT FROM AUTHOR]

To be able to produce ceramic bodies with complex shapes without interlayer delamination and warping through vat photopolymerization‐based 3D printing techniques, photosensitive ceramic slurries should be studied to prepare 3D printed green and sintered bodies. In this study, we developed dual curable acrylate–epoxide ceramic slurries for digital light processing (DLP) 3D ceramic printing. The dual curing process of the slurries is a combination of photo‐radical polymerization of acrylate and thermal cationic polymerization of cyclo‐aliphatic epoxide. The green bodies prepared by dual curing of the slurries showed higher fracture strength and better adhesion between layers and between starting particles and binder polymer in comparison to acrylate‐based green body. These advantages were due to higher crosslinking density of the binder matrix and hydrogen bonding by hydroxyl groups from epoxide ring opening. The green and sintered bodies printed with improved slurry and DLP 3D printer had flat shape without warping unlike those from acrylate‐based bodies. Moreover, the distribution of inter‐particle necking in the sintered body was uniform and the interface boundary between layers was not observed. This is because of excellent uniformity of the dual cured acrylate–epoxide polymer matrix (uniform crosslinking density in layers) in the green body and hydroxyl groups generated by epoxy ring opening. [ABSTRACT FROM AUTHOR]

The warping may become an important factor for the precise transverse vibrations of curved beams. Thus, the first aim of this study is to specify the structural design parameters where the influence of cross-sectional warping becomes great and the first-order shear deformation theory lacks the precision necessary. The out-of-plane vibrations of the first-order shear deformation theory are compared with the warping-included vibrations as the curvature and/or thickness increase for symmetric and asymmetric transversely-functionally graded (TFG) curved beams. The second aim is to determine the influence of design parameters on the vibrations. The circular/exact elliptical beams are formed via curved mixed finite elements (MFEs) based on the exact curvature and length. The stress-free conditions are satisfied on three-dimensional (3D) constitutive equations. The variation of functionally graded (FG) material constituents is considered based on the power-law dependence. The cross-sectional warping deformations are defined over a displacement-type FE formulation. The warping-included MFEs (W-MFEs) provide satisfactory 3D structural characteristics with smaller degrees of freedom (DOFs) compared with the brick FEs. The Newmark method is used for the forced vibrations. [ABSTRACT FROM AUTHOR]

Fused filament fabrication (FFF) is one of the additive manufacturing (AM) techniques that have revolutionized the manufacturing strategy in the last 2 to 3 decades. The quality of the parts prepared by the FFF process is dependent upon the static and variable process parameters. It has been reported by previous studies that part shrinkage, part shrinkage, high surface roughness, warping from the edges, misaligned part geometry, lack and loss of the adhesion, part distortion, voids and porosity etc., are the major issues in the fused filament fabrication process. In the case of open-source fused filament fabrication, internal and external factors such as; the variable room temperatures, room humidity, wind speed, heterogeneity in feedstock materials, torsion in feedstock filaments, vibration due to any source, nozzle clogging, nozzle choking, high/low nozzle and bed temperature are conducive for the mentioned issues. The present study is the state of review for minimizing defects in the final product by suggesting the methods and procedure for each issue in the FFF process. This study would be helpful for novice researchers who are working on different applications of the FFF process. In this review work, most common defects and problems observed during 3D printing are elaborated and discussed according to literature review and also solution of defects has been discussed. [ABSTRACT FROM AUTHOR]

The yield of Eucalyptus regnans logs for lumber production was evaluated. Crack width and length at each log end were measured. Two log-cutting plans were used to obtain sawn lumber. The first plan (PA) considered logs with diameters varying from 28 to 40 cm, and in the second plan (PB), the log diameters ranged from 42 to 56 cm (PB). Lumber yield was determined using two log volume methods: the Japanese Agricultural Standards (JAS) and Smalian's equation. The deformations of E. regnans lumber were measured. The Australian and Chilean standards were used to classify sawn lumber. The results showed that logs had radial cracks at both log ends. Cracks were classified into two groups, considering the crack length. Regarding the lumber deformations, most boards exhibited level B bows and crooks in both cutting plans. Levels A and B twists were prevalent in PA, whereas in PB, level A significantly outnumbered level B. The lumber yield of E. regnans in PB was higher than in PA. The lumber yield determined by Smalian's equation was higher than that determined by the JAS method. This research provides insight into the characterization of E. regnans for lumber production, highlighting its relevance in the forestry industry. [ABSTRACT FROM AUTHOR]

The discussion focuses on the different choices that are made by the user in carrying out shape-based functional data analysis. First, there is the choice of an additional warping penalty that can be included in the procedure. An object-oriented data analysis approach can be useful for selecting such a warping penalty, and an example from monitoring peatland is given. Also, there is a choice to be made about whether the analysis is in a quotient manifold or an ambient space. There are advantages and disadvantages to either strategy, but in many examples, the results are similar due to a Laplace approximation. The final comment states that the authors provide plenty of convincing approaches with many useful insights. It is clear that the square root velocity function (SRVF) and transported SRVF methods will give solutions to many more problems in the future. [ABSTRACT FROM AUTHOR]

In this paper, we show that any displacement of a plate is the sum of a Kirchhoff–Love displacement and two terms, one for shear and one for warping. The plate is then loaded so that bending and shear contribute the same order of magnitude to fiber rotation. [ABSTRACT FROM AUTHOR]

The present work focused on the effect of deposition path on the transient temperature distribution, heat transfer, residual deformation and residual stress of a rectangular solid deposited by electron beam freeform fabrication technology. To achieve this aim, three representative deposition paths were involved to produce rectangular solid by electron beam freeform fabrication technology. Thermal‐mechanical decoupling simulations were carried out with respect to three different deposition paths. Both of the experimental and simulation results showed that a shorter deposition track can remarkably reduce the residual stress and warping. After separating the deposition area into small segments, remarkable local bulges were formed near the conjunction lines, and overheating was prone to occur at the turning points of the conjunction lines. The present work is helpful to the selection of deposition path for additive manufacturing process. [ABSTRACT FROM AUTHOR]

Recent approaches for fast semantic video segmentation have reduced redundancy by warping feature maps across adjacent frames, greatly speeding up the inference phase. However, the accuracy drops seriously owing to the errors incurred by warping. In this paper, we propose a novel framework and design a simple and effective correction stage after warping. Specifically, we build a non-key-frame CNN, fusing warped context features with current spatial details. Based on the feature fusion, our context feature rectification (CFR) module learns the model's difference from a per-frame model to correct the warped features. Furthermore, our residual-guided attention (RGA) module utilizes the residual maps in the compressed domain to help CRF focus on error-prone regions. Results on Cityscapes show that the accuracy significantly increases from 67.3 % to 71.6 % , and the speed edges down from 65.5 FPS to 61.8 FPS at a resolution of 1024 × 2048 . For non-rigid categories, e.g., "human" and "object", the improvements are even higher than 18 percentage points. [ABSTRACT FROM AUTHOR]

We provide statistical analysis methods for samples of curves in two or more dimensions, where the image, but not the parameterization of the curves, is of interest and suitable alignment/registration is thus necessary. Examples are handwritten letters, movement paths, or object outlines. We focus in particular on the computation of (smooth) means and distances, allowing, for example, classification or clustering. Existing parameterization invariant analysis methods based on the elastic distance of the curves modulo parameterization, using the square‐root‐velocity framework, have limitations in common realistic settings where curves are irregularly and potentially sparsely observed. We propose using spline curves to model smooth or polygonal (Fréchet) means of open or closed curves with respect to the elastic distance and show identifiability of the spline model modulo parameterization. We further provide methods and algorithms to approximate the elastic distance for irregularly or sparsely observed curves, via interpreting them as polygons. We illustrate the usefulness of our methods on two datasets. The first application classifies irregularly sampled spirals drawn by Parkinson's patients and healthy controls, based on the elastic distance to a mean spiral curve computed using our approach. The second application clusters sparsely sampled GPS tracks based on the elastic distance and computes smooth cluster means to find new paths on the Tempelhof field in Berlin. All methods are implemented in the R‐package "elasdics" and evaluated in simulations. [ABSTRACT FROM AUTHOR]

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