Three-dimensional Form Research Articles

An optimized three-dimensional time-space domain staggered-grid finite-difference method

Numerical simulation of three-dimensional (3D) seismic wavefields forms the basis of the research on the migration methods of 3D seismic data based on wave equations. Because the simulation precision of wavefield extrapolation determines the imaging accuracy to a certain extent, it is very important to study how to enhance the forward modeling precision of 3D seismic wavefields. Thus, we build on an optimized 3D staggered-grid finite-difference (SFD) method with high simulation precision based on two-dimensional (2D) seismic modeling. Since it generates the corresponding difference coefficients by utilizing the least square (LS) method to minimize the objective function constructed by the time-space domain dispersion relation of the 3D acoustic wave equation, our optimized time-space domain LS-based 3D SFD method can effectively enhance the modeling precision of the 3D seismic wavefields in theory compared with the 3D SFD methods based on the Taylor-series expansion (TE), especially for the large wavenumber range. Examining the numerical dispersion, algorithm stability and computational cost, we compare our optimized time-space domain LS-based 3D SFD method with three conventional TE-based and LS-based 3D SFD methods to illustrate and demonstrate its effectiveness and feasibility. The numerical examples from different 3D models suggest that our optimized time-space domain LS-based 3D SFD method can generate less numerical dispersion and higher simulation accuracy for 3D seismic wavefields than three other conventional 3D SFD methods, but its stability condition is stricter and its computational cost is slightly higher.

On polyharmonic helices in space forms

In this article, we study polyharmonic curves of constant curvature where we mostly focus on the case of curves on the sphere. We classify polyharmonic curves of constant curvature in three-dimensional space forms and derive an explicit family of polyharmonic curves on the sphere. Our results give new insights into the geometric structure of higher order variational problems.

A vision-based approach to mapping flexible objects for garment development

For variable and flexible objects, there is no appropriate intelligent method to quantitatively characterize the three-dimensional (3D) form, especially for garment development. To address the problem, we proposed a novel approach to mapping 3D flexible objects with the coded graphic as a medium. Two-dimensional mapping patterns were used to characterize the 3D form and extract metric information. The proposed graphic code is small in size and it is easy to demonstrate position. With different fabrication techniques, various coding materials are available. With only a monocular image, the method shows high accuracy and low cost without the need for camera calibration in advance. Specifically, the processes of the method, including the algorithm of feature extraction, decoding, mapping position calculation, and pattern generation, are discussed. Two tests were implemented, and the results showed that the method was accurate and simplified the process of made-to-measure garment development. The proposed method has great application potential in the manufacturing of labor-intensive and experience-dependent flexible industries, such as apparel, home decoration, shoes, and other related areas. It also sets the stage for further artificial intelligence research of flexible objects.

Topological phase transition in a quasi-two-dimensional Coulomb gas.

A system with an equal number of positive and negative charges confined in a box with a small but finite thickness is modeled as a function of temperature using mesoscale numerical simulations for various values of the charges. The Coulomb interaction is used in its three-dimensional form, U(r)∼1/r. A topological phase transition is found in this quasi-two-dimensional (2D) system. The translational order parameter, spatial correlation function, specific heat, and electric current show qualitatively different trends below and above a critical temperature. We find that a 2D logarithmic Coulomb interaction is not essential for the appearance of this transition. This work suggests new experimental tests of our predictions, as well as novel theoretical approaches to probe quasi-2D topological phase transitions.

Research on High-Throughput Crop Root Phenotype 3D Reconstruction Using X-ray CT in 5G Era

Currently, the three-dimensional detection of plant root structure is one of the core issues in studies on plant root phenotype. Manual measurement methods are not only cumbersome but also have poor reliability and damage the root. Among many solutions, X-ray computed tomography (X-ray CT) can help us observe the plant root structure in a three-dimensional and non-destructive form under the condition of underground soil in situ. Therefore, this paper proposes a high-throughput method and process for plant three-dimensional root phenotype and reconstruction based on X-ray CT technology. Firstly, this paper proposes a high-throughput transmission for the root phenotyping and utilizing the imaging technique to extract the root characteristics; then, the study adopts a moving cube algorithm to reconstruct the 3D (three-dimensional) root. Finally, this research simulates the proposed algorithm, and the simulation results show that the presented method in this paper works well.

Development of 3D Scanner Application with Stereo Camera for 3D Object Reconstruction

Visual perception in RGBD (Red-Green-Blue and Depth) camera technology allows the camera to provide color image and depth structure information simultaneously from the surface of the scanned object. Based on this technology, data from an RGBD camera can be processed to reconstruct the scanned object in a three-dimensional (3D) model. However, devices that are prebuilt to perform this task with good accuracy are expensive and are only intended for 3D scanning tasks. On the other hand, some multi-purpose depth cameras can be used for 3D scanning but require some tweaks to ensure a good and accurate reconstructed model. A method has been proposed to optimize the camera and reconstruction system to compile RGBD information from recorded close-up objects and process them into a full-scale 3D digital model. This process involves developing the appropriate recording method along with settings and adjustments for scanning and model reconstruction of close-range objects. As a result, information from multi-purpose RGBD camera can be reconstructed in three-dimensional form that accurately represents real-life objects. The reconstructed model can be utilized for applications that rely on real-life objects as their main basis. The proposed method enables the use of inexpensive multi-purpose RGBD cameras for 3D scanning.

The Metabolic Changes between Monolayer (2D) and Three-Dimensional (3D) Culture Conditions in Human Mesenchymal Stem/Stromal Cells Derived from Adipose Tissue

One of the key factors that may influence the therapeutic potential of mesenchymal stem/stromal cells (MSCs) is their metabolism. The switch between mitochondrial respiration and glycolysis can be affected by many factors, including the oxygen concentration and the spatial form of culture. This study compared the metabolic features of adipose-derived mesenchymal stem/stromal cells (ASCs) and dedifferentiated fat cells (DFATs) cultivated as monolayer or spheroid culture under 5% O2 concentration (physiological normoxia) and their impact on MSCs therapeutic abilities. We observed that the cells cultured as spheroids had a slightly lower viability and a reduced proliferation rate but a higher expression of the stemness-related transcriptional factors compared to the cells cultured in monolayer. The three-dimensional culture form increased mtDNA content, oxygen consumption rate (OCR) and extracellular acidification rate (ECAR), especially in DFATs-3D population. The DFATs spheroids also demonstrated increased levels of Complex V proteins and higher rates of ATP production. Moreover, increased reactive oxygen species and lower intracellular lactic acid levels were also found in 3D culture. Our results may suggest that metabolic reconfiguration accompanies the transition from 2D to 3D culture and the processes of both mitochondrial respiration and glycolysis become more active. Intensified metabolism might be associated with the increased demand for energy, which is needed to maintain the expression of pluripotency genes and stemness state.

Comparison Analysis of Usability Using Controllers and Hand Tracking in Virtual Reality Gamelan (Sharon) Based On User Experience

Gamelan is one of the traditional musical instruments in Indonesia. Gamelan is also one of the cultures that must be preserved. To preserve gamelan, one way is by combining gamelan with technology that is currently developing. The technology that is currently trending is virtual reality. Virtual reality is often used for games in three-dimensional form. Gamelan can be something interesting in VR. In VR interactions, there are two interactions that are often used, namely controllers and hand tracking. Hand gestures are usually tracked using the built-in camera of the VR. Hand tracking can be used in VR applications to control the virtual object just like a controllers. This study aims to compare the use of controllers and hand tracking that involve interactions, namely collision, pressing, grabbing, and release. Thirty two Atma Jaya Yogyakarta University students who had tried virtual reality and played gamelan or had seen gamelan performances explore the differences between VR hand tracking and VR controllers in VR gamelan sharon. SUS (System Usability Scale) and USEQ (Use Questionnaire) were used to measure user usability and satisfaction. The result of the SUS score showed that users were more interested in using controllers than hand tracking. But the USEQ results showed that there were no difference in usefulness, ease of use, and satisfication. Based on the results of the interaction, using controllers looked more comfortable, but using hand tracking, playing gamelan looked more realistic.

Application of Augmented Reality Technology to Hospitality French Learning

The delivery of teaching materials in lectures is one of the parts that determine students' understanding of the material presented, especially when lecture materials are things that demand equipment that supports outdoor activities or requires practicum devices that are not possible to be applied to the room, for example in the Unimed French Language Education study program in semester 6. Students will meet the practicum course in the l'hôtellerie or hospitality course this course requires students to imagine being in a hotel directly with all existing activities with a long enough duration. If this course is delivered only in words and sometimes monotonous delivery bores students so that they are less interested in difficulty in mastering the lecture material. One way that can be done to overcome this is to use visual equipment so that what is conveyed in a visual way makes students interested in the material presented and then brings the imagination that they are in a real hotel so that they live the learning in this hospitality course. However, visual delivery in the room is also a problem when the number of learners is large. For this reason, equipment is needed that can provide information visually and is easy to use or carry that can spur student activities to interact. Media augmented reality is a visual model that can provide new experiences in interacting between real objects and virtual objects that are formed in three-dimensional form, using augmented reality packaged as learning material can help students to understand the teaching material in l'hôtellerie lectures.

Phototank setup and focus stack imaging method for reptile and amphibian specimens (Amphibia, Reptilia).

Fluid-preserved reptile and amphibian specimens are challenging to photograph with traditional methods due to their complex three-dimensional forms and reflective surfaces when removed from solution. An effective approach to counteract these issues involves combining focus stack photography with the use of a photo immersion tank. Imaging specimens beneath a layer of preservative fluid eliminates glare and risk of specimen desiccation, while focus stacking produces sharp detail through merging multiple photographs taken at successive focal steps to create a composite image with an extended depth of field. This paper describes the wet imaging components and focus stack photography workflow developed while conducting a large-scale digitization project for targeted reptile and amphibian specimens housed in the University of Colorado Museum of Natural History Herpetology Collection. This methodology can be implemented in other collections settings and adapted for use with fluid-preserved specimen types across the Tree of Life to generate high-quality, taxonomically informative images for use in documenting biodiversity, remote examination of fine traits, inclusion in publications, and educational applications.

Virtual Tour Three Dimensions (3D) With Polygonal Modeling At Sang Nila Utama Museum

Sang Nila Utama Museum is an institution that functions as a place for the storage, care, safeguarding and use of objects of human culture and natural products to support efforts to protect and preserve cultural wealth. Based on the results of the surveys and interviews conducted, there are currently problems, namely 1) There is no system to present information about the collection of objects in the museum visually in 3D. 2) Due to the outbreak of Covid 19 virus, the museum management had to close the museum so far, so the public is not able to visit the museum to get information about the collection of historical relics in the Sang Nila Utama Museum. Based on the problems described above, an Android-based application for a virtual tour of exhibitions of historical objects was developed. The virtual tour is a result of the development of multimedia information technology and 3D technology that can present a 3D atmosphere. In developing this system, the Multimedia Development Life Cycle (MDLC) method was applied, which consists of several phases, namely: concept, design, material procurement, compilation, testing and distribution. This application will later run on the Android platform and use a mobile stick controller as a medium for navigation, allowing users to walk through the museum space to see a collection of historical relics in three-dimensional (3D) visual form. It is expected that this research will be one of the solutions to overcome the problems encountered in trying to improve services to the community.

Long-term changes in 3D urban form in four Spanish cities

Three-dimensional urban form has a considerable influence on urban sustainability, being the reason spatial planning regulate it. Yet, we know very little about the development of building density and building height over time. In this study, we characterize the horizontal and vertical patterns of urban development in Barcelona, Madrid, Valencia, and Zaragoza between 1965 and 2015. Our analysis is based on a unique combination of cadastral data and LiDAR point clouds, which we use to characterize building footprint, height, and volume, at decadal intervals. Subsequently, we characterize urban expansion and densification processes using building volume and Urban Form Types. We find that height of new buildings shows a significant downward trend during the 70′s for the four urban areas and a decreasing trend after the 2008 real estate bubble for the cases of Barcelona and Valencia. Over the analyzed period a decrease of 116, 313, 217 and 157 cm in average building height was observed for Barcelona, Madrid, Valencia, and Zaragoza, respectively. Urbanized volume of all cities together has expanded by roughly 350% between 1950 and 2015. Sparse built-up form showed the largest absolute increase, although it contains only a low fraction of new built-up volume. A clear trend towards expansion is observed in city outskirts and the development of new urban clusters in municipalities closer to the main city. At the same time, settlements have followed incremental steps towards densification of the city-cores over time. This study provides a first step towards comprehensive understanding of long-term changes in 3D urban form, which can inform the development of policies that target the third dimension in urban form to steer sustainable urban growth.

Nanofibrous ZnSnO3/C composite derived from natural cellulose substance as an enhanced lithium-ion battery anode

A new nanofibrous ZnSnO3/C composite material derived from natural cellulose substance (e.g., commercial laboratory cellulose filter paper) was successfully fabricated through a simple hydrothermal synthesis process followed by carbonization treatment. The nanocomposite exhibited enhanced electrochemical performances and delivered a high reversible capacity of 695 mAh/g after 200 cycles at the current density of 100 mA g−1 employed as the anode material of lithium ion battery. The excellent electrochemical properties of the ZnSnO3/C nanocomposite are owing to the hierarchical three-dimensional structure inherited form the initial cellulose substance, which can efficiently buffer the volume expansion during the lithiation/delithiation process to maintain the structural stability of the electrode. In addition, the good conductivity of the carbon matrix in the nanocomposite can facilitate the lithium ion and electron transport upon cycling.

Improving the one-dimensional interfacial area transport equation using a physics-informed machine learning method

The interfacial area concentration modeling has been greatly improved with the development of the interfacial area transport equation (IATE). The one-dimensional IATE, which is obtained through area-averaging the three-dimensional form of the model, has been adopted into many thermal hydraulic analysis codes. Towards improving the performance of one dimensional interfacial area transport equation, along with many of the existing studies on developing sophisticated source and sink constitutive models describing the liquid-bubble and bubble-bubble interactions, additional efforts should be made on improving the accuracies of the closure models supporting the calculation of these constitutive models. In this study, a physics-informed machine learning method was proposed that couples the machine learning and the IATE model for improving the performance of the existing IATE models. The machine learning model serves to predict the errors of the closure models that calculate the key parameters related to the interfacial area transports. The machine learning model is guided by the physical models, and its training is through an IATE model-based loss optimization. To effectively train the machine learning model, a data augmentation method was developed based on the existing IAC database. The newly proposed method that couples the trained machine learning model and the IATE model gives a 12% of improvement compared with the state-of-art IATE model. This new method and the approach on training the model provide good reference on how to effectively couple the machine learning and physical model for an improved modeling of the indirectly observable physical phenomena.

Evaluation of Urban Spatial Structure from the Perspective of Socioeconomic Benefits Based on 3D Urban Landscape Measurements: A Case Study of Beijing, China

Urban spatial structures (USS) play an essential role in urbanization. Understanding the impact of USS patterns on their socioeconomic benefits is crucial to evaluating urban structure quality. Previous studies have, primarily, relied on statistical data and have significant temporal consistency and spatial accuracy limitations. Moreover, previous evaluation methods mainly determined the weight of indicators based on subjective assessments, such as the Delphi method, without integrating the actual socioeconomic benefits of complex urban systems. By measuring the two-dimensional (2D) urban functional landscape patterns and three-dimensional (3D) building forms of the city and considering the level of urban socioeconomic vitality as revealed by nighttime light intensity (NTLI), this study explores the influence of urban spatial structure on socioeconomic vitality. It provides a new perspective for evaluating the USS level. Furthermore, a comprehensive index, namely the Spatial Structure Socioeconomic Benefit Index (SSSBI), was constructed to quantify the socioeconomic benefits of USS. The results showed that (1) the impact of spatial structure on NTLI differs significantly with the distribution of urban functional landscape patterns and building forms. (2) The combined effect of any two spatial structure factors on NTLI was higher than the effect of each factor separately, indicating that multiple dimensions can improve urban spatial construction. (3) This study quantitatively extracts the characteristics of USS from multiple scales, which helps to find the optimal evaluation scale and build a scientific and objective evaluation model. The results showed that the USS assessment based on the SSSBI index is practical. This study could provide a reference for the government’s urban planning and land-use decisions.

Numerical Analysis about the Dynamic Properties of a Pressure Relief Valve and Improvement Measures

In order to investigate the influence of internal flow field on the dynamic characteristics of a pressure reducing valve, based on the new discrete geometric conservation law and high-order coupling algorithm, numerical simulations of the dynamic characteristics have been performed. The three-dimensional unsteady integral forms of ALE equation is solved by finite volume scheme based on the spring analogy method and dynamic grid. The novel techniques of virtual mesh ventilation method is adopted to solve the problem when multiple bodies move from contact to separation and the mesh topology changes. The results show that the outlet pressure of valve oscillates within wide range upstream pressurization rate, the average pressure is close to the theoretical value of static performance design; numerical simulation reappears vibration divergence which is similar to the test phenomenon, flutter phenomenon is caused by the interfere between aerodynamic force and dynamic systems. By modifying the method, the fault can be eliminated.

Lu Town: Theme Parks and the Commodification of Literary Culture in China

This essay investigates Lu Town, a theme park dedicated to the writer Lu Xun (1881–1936) that was established in Shaoxing, China, in 2003. The theme park is a recreation of a fictional town that is an amalgamation of settings from some of Lu Xun’s short stories. The essay seeks to answer the following questions: What happens when the works of a complex and serious writer get popularized in the three-dimensional form of a themed space? Why would one build a theme park around this kind of writer, and how would you capture in a theme park the trenchant critique of rural or small-town social life and traditions in his works? What meanings are invested in this ‘leftist’ writer in a neoliberal ideological climate in which notions of class exploitation and class struggle have all but disappeared? In the process the essay presents a detailed description of the park, based on visits in 2004 and 2018, and an overview of recent changes undertaken to make the park more profitable in the competitive domestic tourist market. The authors argue that Lu Town, driven by commercial concerns, presents a positive, nostalgic representation of small-town Jiangnan life, one that is starkly at odds with the ironic and sardonic attitude Lu Xun often took towards it in his stories.

Redesigning of Industrial Warehouse Layout Using CADD

They take a look at changes in seeking out the most appropriate application of warehouse layout patterns using an extended AutoCAD simulation model. preliminary data changed into won based totally on the financial and overall performance of foremost heavy components providers. both primary and secondary data assets have been processed and analyzed at some point which calculated the ratio of the proportion of location for each type of product class based on sales productiveness and the percentage effects can be applied with CADD simulation (pc Aided layout and Drafting) by using the use of software program software AutoCAD and SketchUp to make clear in viewing pix in three-dimensional form. After the reapply layout is implemented in the utility, the organization can use shade codes and numeric / letter codes to make it smooth in grouping classes of goods. The outcomes indicate that properly-prepared and technology-based warehouse operations brought full-size and giant growth to both efficiency and sales in a selected post-pandemic.

Polyharmonic hypersurfaces into pseudo-Riemannian space forms

In this paper, we shall assume that the ambient manifold is a pseudo-Riemannian space form N^{m+1}_t(c) of dimension m+1 and index t (mge 2 and 1 le tle m). We shall study hypersurfaces {M}^{m}_{t'} which are polyharmonic of order r (briefly, r-harmonic), where rge 3 and either t'=t or t'=t-1. Let A denote the shape operator of {M}^{m}_{t'}. Under the assumptions that {M}^{m}_{t'} is CMC and {{rm{Tr}}},{A}^{2} is a constant, we shall obtain the general condition which determines that {M}^{m}_{t'} is r-harmonic. As a first application, we shall deduce the existence of several new families of proper r-harmonic hypersurfaces with diagonalizable shape operator, and we shall also obtain some results in the direction that our examples are the only possible ones provided that certain assumptions on the principal curvatures hold. Next, we focus on the study of isoparametric hypersurfaces whose shape operator is non-diagonalizable and also in this context we shall prove the existence of some new examples of proper r-harmonic hypersurfaces (r ge 3). Finally, we shall obtain the complete classification of proper r-harmonic isoparametric pseudo-Riemannian surfaces into a three-dimensional Lorentz space form.

Variable-kinematic finite beam elements for geometrically nonlinear dynamic analyses

This article investigates the dynamic nonlinear response of three-dimensional structures using variable-kinematics finite beam elements obtained with the Carrera Unified Formulation. The formalism enables one to consider the three-dimensional form of displacement–strain relations and constitutive law. The deformation mechanisms and the associated couplings are described consistently with the selected kinematic model. The Hilbert–Hughes–Taylor method and the iterative Newton–Raphson scheme are adopted to solve the motion equations derived in a total Lagrangian scenario. Various models have been obtained by using Taylor- and Lagrange-like expansions. The capabilities of the beam elements are assessed considering isotropic, homogeneous structures with compact and thin-walled sections.