Model In Three-dimensional Space Research Articles

Research on multi-beam survey line system based on dynamic programming algorithm

This paper establishes a calculation model for the coverage width and overlap rate of a multi-beam survey line system [1], and optimizes the multi-beam bathymetric survey plan for marine areas. Through the dynamic programming algorithm, a reasonable survey line plan is designed based on the actual marine area depth. The research content includes: Model Establishment: Construct a calculation model for coverage width and overlap rate, determining the coverage width and overlap rate at each position. Three-Dimensional Space Model: Using the survey vessel as the origin and combining marine area information, solve for the coverage width at different angles. Shortest Survey Line Plan: Using the dynamic programming algorithm, determine the shortest survey line plan, with the dynamic transfer equation determined by the overlap rate index. The total length of the survey line in this plan is calculated to be 114,824 meters. Specific Survey Line Plan Design: Using sea depth data and cubic spline interpolation to complete the discrete point plane, construct approximate width and slope. Under the condition of relaxing the overlap rate to 5%-30%, the shortest survey line length is obtained as 398,059 meters, with a missing survey area ratio of 0%, and the total length of parts with an overlap rate exceeding 20% is 25,759 meters, accounting for 6.4%. This study provides theoretical basis and calculation methods for optimizing multi-beam bathymetric survey plans.

Information Analysis of Historically Significant Territories at Various Time Stages of their Development

The paper describes: a structural scheme for representing knowledge about a historically significant territory, providing a formalized informational description of a three-dimensional space model; procedural model for determining the values of the characteristics of a virtual space object; the procedure for creating a realistic virtual model of a historically significant territory, according to which conclusions should be drawn about the development of Its development; carried out Informational analysis of inaccurate data from various primary sources using fuzzy set theory. The technology of creating a virtual historical space using the developed information-logical model and software environments 3DVista Virtual Tour Pro, Twinmotion is described. As a result, a virtual tour has been obtained, which can be used for various purposes: remote consideration of issues related to objects of historical reconstruction; teaching schoolchildren, students; passing educational quests.

A systematic literature review of weak signal identification and evolution for corporate foresight

PurposeWith the intensification of market competition, there is a growing demand for weak signal identification and evolutionary analysis for enterprise foresight. For decades, many scholars have conducted relevant research. However, the existing research only cuts in from a single angle and lacks a systematic and comprehensive overview. In this paper, the authors summarize the articles related to weak signal recognition and evolutionary analysis, in an attempt to make contributions to relevant research.Design/methodology/approachThe authors develop a systematic overview framework based on the most classical three-dimensional space model of weak signals. Framework comprehensively summarizes the current research insights and knowledge from three dimensions of research field, identification methods and interpretation methods.FindingsThe research results show that it is necessary to improve the automation level in the process of weak signal recognition and analysis and transfer valuable human resources to the decision-making stage. In addition, it is necessary to coordinate multiple types of data sources, expand research subfields and optimize weak signal recognition and interpretation methods, with a view to expanding weak signal future research, making theoretical and practical contributions to enterprise foresight, and providing reference for the government to establish weak signal technology monitoring, evaluation and early warning mechanisms.Originality/valueThe authors develop a systematic overview framework based on the most classical three-dimensional space model of weak signals. It comprehensively summarizes the current research insights and knowledge from three dimensions of research field, identification methods and interpretation methods.

Three phase bio-heat transfer model in three-dimensional space for multiprobe cryosurgery

Three phase bio-heat transfer model in three-dimensional space for multiprobe cryosurgery

Three-Dimensional Animation Space Design Based on Virtual Reality

3D animation stereo space design is to process and analyze the collected target image information on the computer and finally obtain a 3D model that can represent the corresponding structure. As a branch of computer vision, 3D animation stereo space design is an important part of realizing the key technology of environment perception. What humans see in the three-dimensional world is a two-dimensional picture. Combined with the visual mechanism and the prior information of the object, it can realize the perception of the environment and promote the convenience of life and production. Games, movies, virtual humans, and any product that uses 3D technology require 3D engine support. The 3D engine encapsulates hardware operations and graphics algorithms and can manage a large number of texture and model resources to construct complex 3D scenes. In order to facilitate the research related to virtual human, in this paper, through the research and study of graphics-related mathematical knowledge and related technologies of engine architecture, an intelligent virtual animation generation engine based on DirectX12 is realized, and three-dimensional characters are controlled through related components, and the function of each module is tested and guaranteed. Test cases were designed to test the various functions of the engine and finally showed that the design goals in the demand analysis have been completed, and a lightweight three-dimensional animation three-dimensional space model has been realized.

Shifted Legendre polynomials algorithm used for the numerical analysis of viscoelastic plate with a fractional order model

An effective numerical algorithm is presented to analyze the fractional viscoelastic plate in the time domain for the first time in this paper. The viscoelastic behavior of the plate is described with fractional Kelvin–Voigt (FKV) constitutive model in three-dimensional space. A governing equation with three independent variables is established. Ternary unknown function in the governing equation is solved by deriving integer and fractional order differential operational matrices of the shifted Legendre polynomials. Error analysis and mathematical example are presented to verify the effectiveness and accuracy of proposed algorithm. Finally, numerical analysis of the plate under different loading conditions is carried out. Effects of the damping coefficient on vibration amplitude of the viscoelastic plate are studied. The results obtained are consistent with the current reference and actual situation. It shows that shifted Legendre polynomials algorithm is suitable for numerical analysis of fractional viscoelastic plates.

Advances in Wind Farm Layout Optimization: Wind Direction Robustness and Wake Induced Asymmetric Thrust Load

In this study, we address the wind farm layout optimization (WFLO) problem and tackle the issue of optimal turbine placement by incorporating additional aspects of an economically driven target function. Firstly, we have analyzed the effect of wind direction on a given turbine arrangement. Based on the direction-dependent wake pattern, practitioners sometimes shut down certain turbines on their farms. Our method computes which turbines should be shut down in which wake situation. On this basis, we have developed a method of finding new turbine setups that rarely require shutdowns and are, in a certain sense, “robust” against changes to the wind direction. Secondly, we have presented a partial coverage Jensen wake model in three-dimensional space and have provided the tools for reducing or avoiding wake-induced asymmetric thrust on the rotor disc of the turbine, which leads to reduced energy yield and accelerated wear. This aspect can also be used for finding new turbine setups that take partial coverage into account and avoid it if necessary. Overall, the application of the refinements suggested in this study will result in an increased yearly profit achieved from the produced energy in a wind farm. This is an aspect that decision-makers, such as farm planners/operators, might depend on in a market that typically possesses narrow profit margins. Our methods find entrance into the open-source research framework that comes as the package wflo for the statistical software R.

Health Monitoring System with Hybrid Laser Sensor Networks and Cloud Computing for Subway Tunnels

The settlement and deformation monitoring for existing tunnels would encounter the difficulties in sensor installation and health evaluation in real time. Thus, it is necessary to develop effective methods for settlement and deformation measurements in the existing tunnels. This study proposed a more practical tunnel deformation monitoring theory and developed remote wireless tunnel deformation real-time monitoring and early warning system based on infrared laser ranging technology and cable sensing technology. The system could monitor the settlement and deformation of the tunnel in real time from a long distance and transmit the deformation data wirelessly in real time; then, three-dimensional space model of tunnel deformation was established, which intuitively and comprehensively reflected the actual deformation of the tunnel and intelligently identified the deformation. Finally, based on the practice of deformation control during tunnel excavation at Xiaohongshu Station of Wuhan Metro Line 8 of China, the measurement results of this new method were compared with the measurement results of particle image velocimetry technology (PIV), the reliability of the new tunnel deformation monitoring method was proved, the settlement error of each monitoring point was found to be less than 1 mm, and the deformation trend was consistent with the actual deformation. The results of this research could provide useful guidance for tunnel deformation monitoring.

Human-centred adaptive control of lower limb rehabilitation robot based on human–robot interaction dynamic model

A rehabilitation robot can effectively alleviate the shortcomings and deficiencies of traditional treatments. The early stages of rehabilitation training use passive control based on a predefined trajectory. The goal of passive control is to control the motion of the robot, rather than the real motion of the human. However, the human and robot are connected by bands; thus, errors exist between them, and these errors affect the outcome of the rehabilitation training. This study proposes human-centred adaptive control of a lower limb rehabilitation robot based on a dynamic model of human–robot interactions. An equivalent spring model in three-dimensional space is proposed for expressing the interaction torque between the human and robot, reflecting the torque exerted by the robot on the human. A dynamic model for the human–robot system is established based on the human–robot interaction model. To overcome the uncertainty regarding the parameters of the human limbs and robots and that of the stiffness coefficient in the interaction force model, an adaptive controller is designed, and the stability of the system is analysed. The simulation results indicate the effectiveness of the controller.

Deformation Monitoring Analysis and Numerical Simulation in a Deep Foundation Pit

This paper mainly focuses on the comparison between the calculated value and actual value of the pile deformation, pile top displacement, and internal support axial force during the excavation of the deep foundation pit, and the influence of excavation method on the deformation. A three-dimensional space model is built using the finite element software MIDAS/GTS to simulate the excavation process of the foundation pit. It is found that the computed data are consistent with the measured values. On this basis the deformation of foundation pit supporting structure under different excavation methods is simulated and optimized to select the excavation method of the foundation pit.

Simulating the Safety of Power Transmission Tower Subjected to Strong Wind Loading

In recent years, with the increase of transmission line height and span, the risks accompanied by transmission towers are significantly increased during the usage of transmission tower. Most of collapsing accidents are caused by strong wind. Therefore, it is necessary to assess the safety of transmission tower. Transmission tower system is a tall building, which is sensitive to the tilt deformation. In order to analyze the mechanical response of transmission tower under strong wind loading, in this paper, the commercial ABAQUS software was employed to create a three-dimensional space model of transmission tower. Firstly, the wind force at different heights of the tower was calculated, and then the wind forces were imposed on each node. By means of finite element method, the deformation of the tower under the strong wind loading was simulated, and its stability was analyzed. Based on the simulated results, the stress field of transmission tower was obtained under strong wind loading. The maximum stress in transmission tower is 189.6 MPa, which is less than the yield strength of steel. The designed transmission power can bear the strong wind of level 10.

Causal relationships between immediate pre-impact kinematics and post-impact kinetics during drop landing using a simple three dimensional multibody model

This study aimed to validate a simple dynamic model of single-leg drop-landing to develop a methodological foundation for investigating mechanistic causes of anterior cruciate ligament (ACL) injury and to explore mechanical associations between knee valgus torque and landing kinematics that are considered clinically as a high-risk landing posture for the injury. A triple-inverted-pendulum model in three-dimensional space, composed of rigid-links of head-arms-trunk (HAT), thigh and shank, was employed. We derived causal relationships that can predict post-impact kinetics, including impact ground reaction forces (GRFs) and corresponding knee joint torques from a given body-kinematics immediately before impact, based on an assumption of a completely inelastic collision between a landing foot (the distal end-point of the shank in the model) and the ground. The concordance correlation coefficient (CCC) analysis revealed that our model can achieve an acceptable agreement between experimentally measured and model-predicted impact GRFs and corresponding knee joint torques. The 95% one-tailed lower confidence limit of CCC of vertical, mediolateral GRFs and the varus/valgus torque were 0.665>ρc,a=0.643,0.786>ρc,a=0.758 and 0.531>ρc,a=0.508, respectively, for the least acceptable values ρc,a. Using this model, effects of three types of hypothetical pre-impact kinematics with modulated (i) medial/lateral leaning HAT angle, (ii) forward/backward HAT tilt-angle, and (iii) knee flexion/extension angle on the impact GRF and corresponding knee joint torque were evaluated. We showed that the smaller knee flexion and the greater HAT leaning toward the landing-limb-side, the larger the knee valgus torque is generated, as a mechanical consequence between the specific pre-impact kinematics and the knee loading associated with the risk of ACL injury. Further exploration of hypothetical kinematics using the model in the future work might contribute to identifying the risky landing kinematics beyond experimental limitations.

Simulations of the Early Postbounce Phase of Core-collapse Supernovae in Three-dimensional Space with Full Boltzmann Neutrino Transport

Abstract We report on the core-collapse supernova simulation we conducted for a 11.2M ⊙ progenitor model in three-dimensional space up to 20 ms after bounce, using a radiation-hydrodynamics code with full Boltzmann neutrino transport. We solve the six-dimensional Boltzmann equations for three neutrino species and the three-dimensional compressible Euler equations with Furusawa and Togashi's nuclear equation of state. We focus on the prompt convection at ∼10 ms after bounce and investigate how neutrinos are transported in the convective matter. We apply a new analysis based on the eigenvalues and eigenvectors of the Eddington tensor and make a comparison between the Boltzmann transport results and the M1 closure approximation in the transition regime between the optically thick and thin limits. We visualize the eigenvalues and eigenvectors using an ellipsoid, in which each principal axis is parallel to one of the eigenvectors and has a length proportional to the corresponding eigenvalue. This approach enables us to understand the difference between the Eddington tensor derived directly from the Boltzmann simulation and the one given by the M1 prescription from a new perspective. We find that the longest principal axis of the ellipsoid is almost always nearly parallel to the energy flux in the M1 closure approximation, whereas in the Boltzmann simulation it becomes perpendicular in some transition regions, where the mean free path is ∼0.1 times the radius. In three spatial dimensions, the convective motions make it difficult to predict where this happens and to possibly improve the closure relation there.

Using direct and contructive methods for the existence of origami models with given boundary conditions

Whenever a unit square is folded to create an origami model in three-dimensional space, the edge of the paper forms a closed curve in space with a total length equal to four units. In this paper, some of the restrictions applicable to such resulting closed curves are derived in the case of classic origami models, in which none of the sections of the folded paper is curved in any way. This allows us to restrict the methods applied to those of classic euclidean geometry. Noting that it is of interest to determine origami models whose edges coincide with a polyline fulfilling the required conditions, we then proceed to show some methods for reconstructing the origami model if the boundary is known. Finally, some concrete reconstructions are demonstrated.

Open quantum dynamics of a three-dimensional rotor calculated using a rotationally invariant system-bath Hamiltonian: Linear and two-dimensional rotational spectra.

We consider a rotationally invariant system-bath (RISB) model in three-dimensional space that is described by a linear rigid rotor independently coupled to three harmonic-oscillator baths through functions of the rotor's Euler angles. While this model has been developed to study the dielectric relaxation of a dipolar molecule in solvation as a problem of classical Debye relaxation, here we investigate it as a problem of open quantum dynamics. Specifically, the treatment presented here is carried out as an extension of a previous work [Y. Iwamoto and Y. Tanimura, J. Chem. Phys 149, 084110 (2018)], in which we studied a two-dimensional (2D) RISB model, to a three-dimensional (3D) RISB model. As in the 2D case, due to a difference in the energy discretization of the total Hamiltonian, the dynamics described by the 3D RISB model differ significantly from those described by the rotational Caldeira-Leggett model. To illustrate the characteristic features of the quantum 3D rotor system described by angular momentum and magnetic quantum numbers, we derive a quantum master equation (QME) and hierarchical equations of motion for the 3D RISB model in the high-temperature case. Using the QME, we compute linear and 2D rotational spectra defined by the linear and nonlinear response functions of the rotor dipole, respectively. The quantum transitions between the angular momentum states and magnetic states arising from polarized Stark fields as well as the system-bath interactions can be clearly observed in 2D rotational spectroscopy.

Study on indoor comfort of floor radiant cooling and displacement ventilation system in large space

Radiant cooling and displacement ventilation system has an extensive application in large space building where there has a significant stratification of heat and mass. This paper focuses on the effects of the floor cooling proportion on the indoor comfort under radiant cooling and displacement ventilation system in large space. By simplifying the building model according to a practical waiting hall in certain railway station, a three-dimensional space model describing the comfort distribution characteristics in working area with composite system is presented. The discrete ordinates radiation model and indoor zero equation model are used to describe the indoor temperature and humidity distribution law. Floor temperature, inlet parameters and the indoor comfort control conditions are researched. The indoor thermal and moist environment is analyzed based on CFD simulation. The simulation results provide that the temperature and velocity of supply air had similar influencing characteristic on the indoor comfort. Meanwhile, the cooling capacity of floor could be higher when the supply air temperature was higher and the air supply velocity was lower and the optimum cooling proportion of floor was 0.76 to 0.77 in this paper. More importantly, the compound system could be applicable in indoor comfort control in large space.

ВИКОРИСТАННЯ B-СПЛАЙНІВ ПРИ РОЗРОБЦІ АВТОМАТИЗОВАНОЇ СИСТЕМИ ГЕОЛОГО-МАРКШЕЙДЕРСЬСКОГО ЗАБЕЗПЕЧЕННЯ

Purpose. The effectiveness of the development of an information system for quarry management is primarily determined by the level of geological and surveying support (GSS), which includes solving such basic tasks as calculating reserves (operational and complete), accounting for ore mining, building the information base for mining planning and management, and field modeling, and career, ore body contouring, etc. The purpose of this work is to develop and use B-Splines in the automation of geological surveying software in the quarry. Research methods. The basis of many tasks is the construction of surfaces. For the first time in recent years, an uneven rational Bspline (NURBS) is used to describe them, which most fully satisfies the following criteria: the model's adequacy to the real representation, the efficiency of model formation and surface construction, and the visualization of the model in three-dimensional space. Scientific novelty. The advantages of constructing surfaces using NURBS are as follows: ease of calculation; sufficient smoothness; construction of the surface of any degree of complexity; using the weights of the control points, control of the surface (it can pass strictly through the specified control points). The latter property made it possible with the help of a NURBS surface to effectively model the day surface of a quarry with a strict passage of the surface through points of the ledges. Practical significance. For the joint Russian-Mongolian enterprise Erdenet (Mongolia), developing the copper-molybdenum deposit, an integrated automated GSS system has been developed and has been in operation for many years. Software and algorithmic tasks of the system are constantly being improved. This article presents its latest developments and development paths. The use of NURBS allowed us to construct the day surface of the open-pit mine, to improve the complete calculation of reserves, the accounting of ore mining, and the delineation of ore bodies along the open-pit horizons. Results. The software is implemented in C++ and C# for Windows. To build three-dimensional graphics, the tools of the open graphic library OpenGL are used. Separate modules of the developed GSS system were used at the Novokrivoyorogsk and Ingulets mining and processing plants. The methodology for constructing automated GSSs has been approved by many years of positive experience in industrial implementation and can be used for non-ferrous ore and iron ore deposits.

Measurement and Modelling of Leakage Current Behaviour in ZnO Surge Arresters under Various Applied Voltage Amplitudes and Pollution Conditions

In zinc oxide (ZnO) surge arresters, leakage current usually flows across the arrester under normal operating condition. Leakage current is one of the factors which contribute towards degradation of surge arresters and therefore, it is very important to monitor the condition of surge arrester. In this work, the behaviour of leakage current in a ZnO surge arrester during normal operation, under different voltage amplitudes, wetness and pollution conditions was analysed. An 11 kV surge arrester model in three-dimensional space was subjected to finite element analysis (FEA) to determine the leakage current under different conditions. The results from the FEA model were compared with the measurement results to validate the model that has been developed. From comparison between the measurement and simulation results, physical parameters of a surge arrester that influence the leakage current under different conditions of the surge arrester were identified from the model. Through this work, a better understanding of leakage current behaviour can be attained, which may help in condition monitoring analysis on surge arrester in electrical utilities.

Cloth Simulation with Adaptive Force Model in Three-Dimensional Space

An adaptive force model is proposed to achieve better performance between the accuracy and the speed of cloth simulation in three-dimensional (3D) space. The proposed force model can be expressed with a general mathematical form demonstrated by the distance between the clothing and the human body. This paper defines how a continuous adaptive area can be established with a shape “block”. It is clarified that, within a specific block, a force model is expressed with the gravity of the clothing, the forces of the adjacent blocks and the anti-force of the human body to the block. In this manner, the force model of the desired clothing can be obtained through a general mathematical expression. The simulations and experimental results demonstrate that the acceptable clothing simulation in 3D space can be achieved with higher speed by saving about 20.2% runtime, and the efficiency of the proposed scheme can be verified.

Numerical simulation of the zebra pattern formation on a three-dimensional model

In this paper, we numerically investigate the zebra skin pattern formation on the surface of a zebra model in three-dimensional space. To model the pattern formation, we use the Lengyel–Epstein model which is a two component activator and inhibitor system. The concentration profiles of the Lengyel–Epstein model are obtained by solving the corresponding reaction–diffusion equation numerically using a finite difference method. We represent the zebra surface implicitly as the zero level set of a signed distance function and then solve the resulting system on a discrete narrow band domain containing the zebra skin. The values at boundary are dealt with an interpolation using the closet point method. We present the numerical method in detail and investigate the effect of the model parameters on the pattern formation on the surface of the zebra model.