Three-dimensional Spatial Model Research Articles

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.

Curving Performance of Straddle-Type Monorail Vehicle with Single-Axle Bogies Based on Spatial Multi-Body Dynamic Analysis

Straddle-type monorail ,as a unique technology, energy saving and environmental protection, is different from the subway of urban rail transit system. In order to study the curving performance of a new type of the straddle-type monorail vehicle with single-axle bogies ,the three-dimensional spatial dynamics model which consists of the vehicle model and track model designis proposed by the multi-body dynamics soft ADAMS. The monorail vehicle dynamic model which consists of three types of tire -track contact model and the nonlinear model of the horizontal stop is established. Based on the dynamic model, the influences such as pre pressure and curve super-high rate parameters of the curve passing for the dynamic characteristics are discussed. The simulation results show that the suitable preload for the guide and stabilizer tires of straddle-type vehicle with single-axle bogies is 5KN and after selecting the appropriate pre-pressure, the super-high rate is recommended to be 8%-10%.

The digital model as a key tool for preserving architectural heritage in strategic master planning

The possibilities and role of a three-dimensional spatial model are considered on the example of the historical and architectural Usolye Stroganovsky museum-reserve strategic master plan (Perm region). In the context of heritage preservation, the master plan was shown not only as a strategic document, but also as a communication tool between various branches of government in order to integrate heritage protection policy into the system of general urban planning policy. The methodological approach is based on use of a digital three-dimensional model obtained by laser scanning and photogrammetry. A portable and ground-based laser scanning to create the point cloud is presented. The architectural and urban planning solutions of the strategic master plan are based on the dynamic 3D model and static visualizations of individual elements. The results of virtual reconstruction are shown. The level of detail of 3D models is LOD 200. Virtual reconstruction and visualization have shown themselves not only as a reliable communication tool for the decision-making management, but also as a way to quickly obtain a complex of urban planning and design documentation suitable for reconstruction and restoration of historical and architectural heritage.

Dynamic Response Characteristics of the Structures under Excavation by High-Efficiency Blasting in the Urban Ultradeep Foundation Pit

To ensure the safe and efficient excavation of ultradeep foundation pits in a complex urban environment, the ultradeep foundation pit excavation project of Liuguangmen Urban Complex in Guiyang City was taken as the study point. A high-efficiency blasting method was proposed for the excavation of vibration-isolating slot and electronic detonators, and a three-dimensional spatial calculation model of the foundation pit structure was established. In addition, the field test and numerical simulation of the blasting vibration were developed. The feasibility of the high-efficiency blasting method was demonstrated, and the propagation law of the dynamic response characteristic parameters of the structure was explored using an electronic detonator and vibration-isolating slot. The results show that the electronic detonator carried out peak shaving within the group, unloading waves between the groups, and the blocking effect of the vibration-isolating slot, and all these effectively reduced the peak stress and peak particle vibration velocity, evenly distributed the vibration velocity, and guaranteed the safety of the surrounding existing buildings, proving the feasibility of the efficient blasting method. There is a “wall effect” at the supporting pile, whose propagation velocity is lower than that inside the rock mass, and the PPV is radial X > tangential Y > vertical Z. The peak values of stress, strain, and PPV all decrease with increasing supporting pile height, and there is an inflection point at 20 m. The internal nodes of the pile reciprocate without sharp change and failure in displacement. The peak displacement of different nodes is in the order X > Y > Z with increasing pile height, and the maximum peak value is 0.08 mm.