Three-dimensional Spatial Model Research Articles

An automatic method of siltation depth detection and 3D modeling in water-filled sewer pipelines based on sonar point clouds

Underground sewer pipeline inspection is essential for ensuring the safety and sustainability of urban infrastructure and improving residents’ quality of life. Traditional sewer pipeline inspection methods incur high manual costs. Therefore, this paper proposes an automated siltation depth identification and three-dimensional pipeline model reconstruction using an iterative farthest point removal fitting process based on a sonar point cloud. This method includes interpreting raw sonar data into point cloud data, point cloud preprocessing, iterative farthest point removal fitting process to fit pipeline profile and reverse interpolation of pipeline slices for three-dimensional model reconstruction. This method is validated in real-world applications, successfully calculating and annotating silt depth for pipeline slice profiles. The quantitative analysis shows an error in the estimated siltation proportion fluctuating within approximately 1%. This method also reconstructs the three-dimensional spatial model of siltation in the sewer pipeline, thereby providing effective technical support for engineering applications and reducing manual effort.

Three-Dimensional Obstacle Avoidance Harvesting Path Planning Method for Apple-Harvesting Robot Based on Improved Ant Colony Algorithm

The cultivation model for spindle-shaped apple trees is widely used in modern standard apple orchards worldwide and represents the direction of modern apple industry development. However, without an effective obstacle avoidance path, the robotic arm is prone to collision with obstacles such as fruit tree branches during the picking process, which may damage fruits and branches and even affect the healthy growth of fruit trees. To address the above issues, a three-dimensional path -planning algorithm for full-field fruit obstacle avoidance harvesting for spindle-shaped fruit trees, which are widely planted in modern apple orchards, is proposed in this study. Firstly, based on three typical tree structures of spindle-shaped apple trees (free spindle, high spindle, and slender spindle), a three-dimensional spatial model of fruit tree branches was established. Secondly, based on the grid environment representation method, an obstacle map of the apple tree model was established. Then, the initial pheromones were improved by non-uniform distribution on the basis of the original ant colony algorithm. Furthermore, the updating rules of pheromones were improved, and a biomimetic optimization mechanism was integrated with the beetle antenna algorithm to improve the speed and stability of path searching. Finally, the planned path was smoothed using a cubic B-spline curve to make the path smoother and avoid unnecessary pauses or turns during the harvesting process of the robotic arm. Based on the proposed improved ACO algorithm (ant colony optimization algorithm), obstacle avoidance 3D path planning simulation experiments were conducted for three types of spindle-shaped apple trees. The results showed that the success rates of obstacle avoidance path planning were higher than 96%, 86%, and 92% for free-spindle-shaped, high-spindle-shaped, and slender-spindle-shaped trees, respectively. Compared with traditional ant colony algorithms, the average planning time was decreased by 49.38%, 46.33%, and 51.03%, respectively. The proposed improved algorithm can effectively achieve three-dimensional path planning for obstacle avoidance picking, thereby providing technical support for the development of intelligent apple picking robots.

Space Behind Abstraction: The Metamorphosis of Shape

Purpose: to demonstrate the relation among various architectural contents, whose synthesis is materialized in thedesign of the architectural space. Method: to develop, in the context of the curricular unity of Drawing, of the Architecture Program, the conception of an architectural space, through an exploratory exercise, using the abstraction of a spot as a starting point, in order to achieve, by its metamorphosis, different kind of spaces, which reflect its main characteristics. The process isexperimental, from the analysis and interpretation of the intrinsic qualities of the spot, to the conception of a threedimensional spatial model. Results and conclusion: the perception that the formulation of space, in architecture, is a synthesis of severalknowledges. This exercise shows, taking as a starting point something so abstract as a spot, one can, through anexperimental process of interpretation, obtain architectural space.

Evaluating the load-bearing capacity of corroded cables in long-span cable-stayed bridges: A stochastic corrosion field simulation approach

In cable-stayed bridges, cables are the primary load-bearing components. The corrosion of high-strength steel wires within these cables can degrade their bearing capacity, which in turn impacts the safety and durability of long-span cable-stayed bridges. To address this concern, a three-dimensional random field model was proposed in this study to evaluate the residual bearing capacity of corroded cables. This model considers the random distribution of the strength of high-strength wires along both axial and cross-sectional directions caused by corrosion. Subsequently, a three-dimensional spatial correlation model was developed based on field test results from two stay cables in service on an actual bridge. This model represents the strength distribution of corroded high-strength steel wires within the cable. Finally, the evaluation model developed in this study was employed to assess the bearing performance of two corroded cables with different degrees of corrosion. The results were then compared with test outcomes. The results show that the proposed evaluation model can accurately estimate the bearing performance of corroded cables.

Exploring seismic resilience in frame structures through advanced numerical modeling and dynamic nonlinear analysis of recycled aggregate concrete

This study developed an advanced three-dimensional spatial model to examine the behavior of Recycled Aggregate Concrete (RAC) frame structures using sophisticated nonlinear beam-column fiber elements. It thoroughly investigates the dynamic properties such as natural frequency, vibration modes, and stiffness of RAC structures and conducts a detailed nonlinear dynamic analysis focusing on acceleration, displacement, drift, and hysteresis curves. The seismic resilience of RAC structures, especially inter-story drift under various seismic intensities, was evaluated and compared with Natural Aggregate Concrete (NAC) structures by adjusting the concrete material model parameters in the finite element framework. The accuracy of the numerical model was validated against shaking table tests, showing that RAC and NAC structures comply with structural damage criteria across seismic phases from 0.066 g to 1.170 g. The findings suggest RAC structures are as seismically resilient as NAC ones, making them suitable for earthquake-prone areas.

Dynamic modeling and vibration control optimization of a rotating hollow beam with ESACLD treatment

As an active and passive hybrid control technology, enhanced segmented active constrained layer damping (ESACLD) is an intelligent damping structure for suppressing adverse vibrations in flexible structures. In this study, the three-dimensional spatial dynamic model of a rotating hollow beam with improved ESACLD treatment is established based on the finite element method in a floating frame of reference. The damping effects of the ESACLD with both edge elements and incisions are considered in the dynamic model for the first time. Simulation results show the damping performance of the ESACLD is better than traditional active constrained layer damping with or without incisions (SACLD or ACLD). The Genetic Algorithm-Backpropagation (GA-BP) neural network is used to optimize the physical parameters of ESACLD, and the optimized model can effectively suppress the transverse and flapping bending vibration. It is also found that flapping and transverse bending vibrations exhibit differential dependence on nutation and precession angular velocities; higher nutation and lower precession velocities suppress flapping bending. The existing commercial finite element software has some problems, such as low efficiency and inaccuracy. The new finite element proposed in this paper uses a new form function to ensure accuracy in the simulation of rotation and vibration and has obvious advantages in dealing with rotational structures and complex boundary conditions. Research in this work can provide a design framework for vibration prediction and control of flexible beam-like structures.

DISCOVERY OF A NEW MORPHOLOGICAL FEATURE IN FORENSIC MEDICINE DURING THE STUDY OF GUNSHOT INJURY USING THREE-DIMENSIONAL MODELING OF THE WOUND CHANNEL

The use of spatial three-dimensional modeling of the main elements of a gunshot injury plays a significant part in the modern forensic medical examination. It allows not only to improve the visualization of such bodily injuries, to increase the objectivity and validity of expert conclusions, to accumulate an evidence basis for war crimes committed with the use of various types of firearms, but it also helps to discover new morphological features which couldn’t be detected when using traditional research methods. The work shows the process of detecting a new morphological feature during three-dimensional modeling of the wound channel caused by the IJ 70-01 pistol loaded with 9 mm cartridges.
 Aim of the work. Demonstration of new possibilities of three-dimensional spatial modeling in the process of the forensic investigation of a gunshot wound.
 Materials and methods. To achieve the aim of study, a series of experimental shots were fired from the IJ 70-01 automatic pistol loaded with 9 mm cartridges. To conduct bench ballistic tests according to the US standards – NIJ (National Institute of Justice), HOSDB (Home Office Scientific Development Branch) – standardized ballistic clay Roma Plastilina No.1 was used as the main material that absorbs the energy of the bullet and reproduces all the elements of wound ballistics. It was coated in pig skin with subcutaneous adipose tissue in order to recreate more true-to-life conditions of the gunshot injury. The generated wound channel was filled with Tropicalgin alginate impression material (Zhermack, Italy), which was mixed according to the manufacturer’s instructions; it has short setting time and reproduces the smallest details of the wound channel. Thereafter, the formed cast of the wound channel was subjected to a series of photographs at the appropriate angles and its 3D model was created with the help of the graphic design software “Agisoft PhotoScan” and “3ds max”.
 Results. The result of the conducted studies was obtaining a spatial three-dimensional model of the gunshot wound channel, which brings about new opportunities for its research. The implementation of three-dimensional modeling techniques made it possible to discover a new morphological feature – a helical torsion of the wound channel, the direction of which can indicate specific design features of the firearm used.
 Conclusions. The implementation of three-dimensional spatial modeling in the process of a gunshot trauma investigation sets conditions for increasing visibility and objectivity during conduction of such forensic medical examinations. At the same time, new opportunities are brought about for taking linear dimensions of the existing morphological features of the wound channel main elements with extended precision, the accumulation of demonstrative evidence basis in cases of such injuries, and the discovery of new morphological features for identification of the specific design features of the firearm used.

Fault diagnosis of rolling bearing based on the three-dimensional coupled periodic potential-induced stochastic resonance

Abstract Conventional bistable and monostable stochastic resonance (SR) methods exhibit certain limitations in their capacity to enhance and extract incipient characteristics. Firstly, the inherent potential function structure, characterized by a singular stable-state paradigm, proves inadequate in accommodating the heterogeneous and multifaceted condition monitoring signals. Secondly, the interconnected dynamic characteristics of the mechanical signals remain unaccounted for. Furthermore, conventional SR methods persist in utilizing a fixed constant as the critical system parameter, thereby neglecting the synergistic interaction among monitoring signals, potential function structures, and scale factors. Owing to the rich dynamic characteristics of the three-dimensional multi-stable coupled periodic potential SR system, it demonstrates superior noise utilization compared to monostable and bistable systems. In view of this, the present formulates a three-dimensional spatial model employing a coupled periodic potential model with nonlinear coupling. Subsequently, a pioneering method for diagnosing rolling bearing faults is introduced, utilizing the framework of three-dimensional multi-stable coupled periodic potential-induced SR. Simulation and experimental results illustrate that this approach effectively enhances and extracts the subtle fault characteristics of rolling bearings, ensuring a clear distinction between the spectral peak at the bearing fault characteristic frequency and the spectral peak originating from the interference noise.

Simulation of emergency evacuation with crowd-gathering risk and evaluation methods: a case study of the mass rapid transit system in Taipei

ABSTRACT Mass rapid transit (MRT) systems are the backbone of transportation infrastructure in many cities. During emergencies, indoor subway stations become particularly susceptible to panic and overcrowding, making evacuation difficult. Therefore, simulating the evacuation and sheltering processes of a large number of individuals during emergencies is key in urban disaster response. In this study, a spatial evacuation risk model was used to enhance the safety of evacuation strategies in an MRT system. Data were collected on spatial architectural floor plans, and a database for communication and pedestrian flow was established. The behavioral patterns and distribution of individuals within stations and the characteristics of refuge spaces were also investigated. To simulate the processes of evacuation and sheltering, the Pathfinder evacuation simulation tool was used to construct a three-dimensional spatial model of a subway station. Specific scenarios were then constructed to simulate the procedures of evacuation and sheltering. Subsequently, the factors contributing to overcrowding-related hazards were analyzed to examine the spatial risks associated with crowd aggregation and evacuation and provide recommendations for improvement. Given its numerous advantages, this approach can serve as a valuable reference for conducting risk assessments in other large-scale crowd aggregation spaces.

Criterias for the formation of large ore deposits in Uzbekistan

The article presents new data on the study of ore deposits in Uzbekistan in recent years in the laboratory “Structure of the lithosphere”. Based on the complex of regional geophysical data, a three-dimensional geological and geophysical analysis of the relief, basement and Mohorovicic surfaces was carried out in software ArcGIS 10.1. A three-dimensional spatial dynamic model of the Central Kyzylkum Ore-Magmatic concenter was developed on the basis of a complex methodology, including an integrated analysis of the placement of deep structures, the relationships of objects and phenomena using modern methods of spatial analysis and geomodelling. New potentially promising areas for gold mineralization of the Muruntau type have been elucidated within the Central Kyzylkum Ore-Magmatic Concentre (CKOMC).

Типология педагогического взаимодействия субъектов образовательного процесса в вузе: полисубъектный подход

The aim of the study is to build a typology of pedagogical interaction between teachers and students at university, to identify the characteristics of the interaction types that are of polysubject nature. The professional training of a future specialist at university is considered by the authors in the context of pedagogical interaction between education subjects based on a polysubject approach. The typology of pedagogical interaction between the subjects of the educational process at university is built using a three-dimensional spatial model that includes a system of basic relations between interaction subjects (attitude to themselves, to others and to joint activities), which can be represented as axes of a certain coordinate system: “individualism – collectivism”, “egoism – altruism”, “reactivity – proactivity”. This constitutes the scientific novelty of the study. As a result, it has been determined that within the framework of this model, the space of pedagogical interaction exists within roughly divided subspaces, i.e. its types: self-affirmation, leadership, use, rivalry, agreement, dialogue/polylogue, mentorship/guardianship, cooperation/partnership. The types of interaction that are polysubject are dialogue/polylogue, cooperation/partnership. Polysubject interaction is based on the humanistic idea of co-existence, co-operation and co-creativity of students and teachers. The training of a future specialist at university is considered as a dialogical, polyphonic process focused on self-development, self-accomplishment, self-realisation and self-actualisation of education subjects in polysubject interaction, as a process of co-development of a teacher and a student.

Dynamic Response Analysis of Orthotropic Saturated Subgrade-Pavement Slab

Based on the Kirchhoff thin plate theory, a three-dimensional spatial mechanical model of the subgrade pavement with an infinite elastic plate on the orthotropic saturated foundation in the rectangular coordinate system is established, and the differential equations under a moving harmonic load are derived. The partial differential equations are solved by using coordinate transform and Fourier transform, and the analytical solutions of the dynamic responses of the plate and foundation are obtained. A three-dimensional spatial finite element model of subgrade-pavement is established by ABAQUS finite element software. The correctness of the method is verified by comparing the theoretical solution with the finite element solution. The influence of foundation parameters on plate displacement and vertical normal stress of soil is further studied. The results show that considering the orthogonal anisotropy of saturated soil, the dynamic response of subgrade-pavement slab interaction can be described more accurately.

Research of the Solutions Proximity of Linearized and Nonlinear Problems of the Biogeochemical Process Dynamics in Coastal Systems

The article considers a non-stationary three-dimensional spatial mathematical model of biological kinetics and geochemical processes with nonlinear coefficients and source functions. Often, the step of analytical study in models of this kind is skipped. The purpose of this work is to fill this gap, which will allow for the application of numerical modeling methods to a model of biogeochemical cycles and a computational experiment that adequately reflects reality. For this model, an initial-boundary value problem is posed and its linearization is carried out; for all the desired functions, their final spatial distributions for the previous time step are used. As a result, a chain of initial-boundary value problems is obtained, connected by initial–final data at each step of the time grid. To obtain inequalities that guarantee the convergence of solutions of a chain of linearized problems to the solution of the original nonlinear problems, the energy method, Gauss’s theorem, Green’s formula, and Poincaré’s inequality are used. The scientific novelty of this work lies in the proof of the convergence of solutions of a chain of linearized problems to the solution of the original nonlinear problems in the norm of the Hilbert space L2 as the time step τ tends to zero at the rate O(τ).

Rural Spatial Differentiation and Revitalization Approaches in China: A Case Study of Qingdao City

Rural revitalization, as a major strategy with the goal of realizing the overall development of strong agriculture industries, beautiful rural areas, and rich farmers, is an effective way of alleviating the loss of talent, land, capital, and other elements in rural areas and a possible cure for "rural diseases". However, "rural diseases" faced by villages are very different, and thus exploring suitable strategies for rural revitalization is beneficial to the implementation of rural revitalization strategies and the promotion of urban-rural integration. Based on location theory, this paper constructs a point-axis-domain three-dimensional spatial location theory model that integrates market location, traffic location, and natural location and combines the coupling coordination model to comprehensively study the vitality and development directions of Qingdao's rural areas. Results found that Qingdao's high-level and medium-high-level coupling coordination areas are the main types of coupling coordination, accounting for 45.19% and 47.48%, respectively. Based on the development status of Qingdao, this study explores development directions for rural revitalization poles as well as high-level, medium-high-level, and medium-level coupling coordination areas and suggests the following: rural revitalization poles should play a demonstration role in rural revitalization in terms of industrial development, rural civilization, social governance, public service construction, etc.; high-level coupling coordination areas should focus on building modern hi-tech agriculture and rural marine tourism industries; medium-high-level coupling coordination areas should strengthen the building of satellite towns and promote industrial transformation and upgrading; medium-level coupling coordination areas should actively develop ecological environment conservation models and establish a characteristic mountainous eco-tourism industry. Thus, the findings provide important scientific reference for the implementation of rural revitalization.

CT-Loc: Cross-domain visual localization with a channel-wise transformer

We tackle the cross-domain visual localization problem of estimating camera position and orientation from real images without three-dimensional (3D) spatial mapping or modeling. Recent studies have shown suboptimal performance in this task owing to the photometric and geometric differences between synthetic and real images. In this study, we present a deep learning approach that uses a channel-wise transformer localization (CT-Loc) framework. Inspired by the human behavior of looking for structural landmarks to estimate one’s location, CT-Loc encodes the most salient features of task-relevant objects in target scenes. To evaluate the efficacy of the proposed method in a real-world application, we built a complex and large-scale dataset of the interior of the mechanical room during operations and conducted extensive performance comparisons with the publicly available state-of-the-art University of Melbourne Corridor and Virtual KITTI 2 datasets. Compared with the otherwise best-performing BIM-PoseNet indoor camera localization model, our method significantly reduces position and orientation errors through the application of attention weights and saliency maps while also learning only the visual structural patterns (e.g., floors and doors) that are most relevant to localization tasks. Our model successfully ignores uninformative objects. This approach yields higher-level robust camera-pose regression localization results without requiring prebuilt maps. The code is available at https://github.com/kdaeho27/CT-Loc.

Dynamic and probabilistic seismic performance assessment of precast prestressed reinforced concrete frames incorporating slab influence through three-dimensional spatial model

Dynamic and probabilistic seismic performance assessment of precast prestressed reinforced concrete frames incorporating slab influence through three-dimensional spatial model

Analysis of formation methods of graphic competence of future engineering teachers

The article substantiates the need to improve the formation methods of graphic competence of future engineering teachers by means of digital technologies. To achieve the goal of the article the analysis of normative documents of training of future engineering teachers in the field of digital technologies, methods of teaching graphic disciplines in Higher Education Institutionі, prospects of improving graphic training of future engineering teachers by means of digital technologies are determined. Based on the analysis of work programs of the cycle of disciplines of graphic training, we conclude that today the method of formation of graphic competence in future engineering teachers in the field of digital technologies needs to be improved.
 It is established that the most effective way to reform the system of training future engineering teachers in the field of digital technologies is the use of modern learning technologies, which include design, research, integrative technologies that provide personality-oriented learning and graphic competence of future engineering teachers in the field digital technologies. It is determined that it is necessary to improve the teaching methods of the discipline "Engineering Computer Graphics", which will include the study of two-dimensional graphics, three-dimensional spatial modeling, 3D printing technologies and the creation of 4D objects in KOMPAS-3D.

FPGA Acceleration of 3GPP Channel Model Emulator for 5G New Radio

The channel model is by far the most computing intensive part of the link level simulations of multiple-input and multiple-output (MIMO) fifth-generation new radio (5G NR) communication systems. Simulation effort further increases when using more realistic geometry-based channel models, such as the three-dimensional spatial channel model (3D-SCM). Channel emulation is used for functional and performance verification of such models in the network planning phase. These models use multiple finite impulse response (FIR) filters and have a very high degree of parallelism which can be exploited for accelerated execution on Field Programmable Gate Array (FPGA) and Graphics Processing Unit (GPU) platforms. This paper proposes an efficient re-configurable implementation of the 3rd generation partnership project (3GPP) 3D-SCM on FPGAs using a design flow based on high-level synthesis (HLS). It studies the effect of various HLS optimization techniques on the total latency and hardware resource utilization on Xilinx Alveo U280 and Intel Arria 10GX 1150 high-performance FPGAs, using in both cases the commercial HLS tools of the producer. The channel model accuracy is preserved using double precision floating point arithmetic. This work analyzes in detail the effort to target the FPGA platforms using HLS tools, both in terms of common parallelization effort (shared by both FPGAs), and in terms of platform-specific effort, different for Xilinx and Intel FPGAs. Compared to the baseline general-purpose central processing unit (CPU) implementation, the achieved speedups are 65X and 95X using the Xilinx UltraScale+ and Intel Arria FPGA platform respectively, when using a Double Data Rate (DDR) memory interface. The FPGA-based designs also achieved ~3X better performance compared to a similar technology node NVIDIA GeForce GTX 1070 GPU, while consuming ~4X less energy. The FPGA implementation speedup improves up to 173X over the CPU baseline when using the Xilinx UltraRAM (URAM) and High-Bandwidth Memory (HBM) resources, also achieving 6X lower latency and 12X lower energy consumption than the GPU implementation.

Spatial distribution modeling of subsurface bedrock using a developed automated intelligence deep learning procedure: A case study in Sweden

Due to associated uncertainties, modelling the spatial distribution of depth to bedrock (DTB) is an important and challenging concern in many geo-engineering applications. The association between DTB, the safety and economy of design structures implies that generating more precise predictive models can be of vital interest. In the present study, the challenge of applying an optimally predictive three-dimensional (3D) spatial DTB model for an area in Stockholm, Sweden was addressed using an automated intelligent computing design procedure. The process was developed and programmed in both C++ and Python to track their performance in specified tasks and also to cover a wide variety of different internal characteristics and libraries. In comparison to the ordinary Kriging (OK) geostatistical tool, the superiority of the developed automated intelligence system was demonstrated through the analysis of confusion matrices and the ranked accuracies of different statistical errors. The results showed that in the absence of measured data, the intelligence models as a flexible and efficient alternative approach can account for associated uncertainties, thus creating more accurate spatial 3D models and providing an appropriate prediction at any point in the subsurface of the study area. • Two automated deep learning intelligence models through C++ and Python were developed. • 3D pattern of subsurface geo-spatial DTB distributions for Stockholm, Sweden was presented. • The visualised predicted model using C++ showed more accurate results than Python and OK. • Flaws of OK in modelling the limited and heterogeneous distributed data were demonstrated. • The capacity of intelligence models for subsurface DTB characterizing was improved.

An Analysis of Network Structure in Mazda’s Yokokai using the DEC Spatial Model

By examining networks is possible to understand the nature of inter-firm relationships among organizational entities in any given corporate group, such as Toyota’s, Nissan’s or Mazda’s Keiretsu. Recently, a new three-dimensional spatial model has been developed that allows organizational scholars to ascertain the structure of a corporate group, the position of the individual firms, and the determinants of the firm performance. This new spatial paradigm –called the DEC spatial model– composed of degree, effective size and capacity that assessed the relationship between Euclidean distance and sales. Although it advances our understanding of networks, the bulk of the research is based on cross-sectional data, it is not possible ascertain the real nature of the relationship between the distance and sales. Instead, the analysis of networks requires using time series data as all the corporate members of a network are ongoing- concerns. To augment our understanding of the nature of inter-firms networks, the interrelationship between distance and sales is examined using time series data drawn from Mazda’s Yokokai in 1986, 2004 and 2005. More specifically, in this paper the data on transactions were collected and used to calculate the Euclidean distance using the DEC spatial model. The position and its determinants of all individual firms are identified and the trend of structure changes is discussed. Based on the findings of offered and avenues of future research are suggested.