Three-dimensional Simulation System Research Articles

Real-time Risk Assessment for Aids to Navigation Using Fuzzy-FSA on Three-Dimensional Simulation System

The risk level of the Aids to Navigation (AtoNs) can reflect the ship navigation safety level in the channel to some extent. In order to appreciate the risk level of the aids to navigation (AtoNs) in a navigation channel and to provide some decision‐making suggestions for the AtoNs Maintenance and Management Department, the risk assessment index system of the AtoNs was built considering the advanced experience of IALA. Under the Formal Safety Assessment (FSA) frame, taking the advantages of the fuzzy comprehensive evaluation method, the fuzzy‐FSA model of risk assessment for aids to navigation was established. The model was implemented for the assessment of aids to navigation in Shanghai area based on the aids to navigation three‐dimensional simulation system. The real‐time data were extracted from the existing information system of aids to navigation, and the real‐time risk assessment for aids to navigation of the chosen channel was performed on platform of the three‐dimensional simulation system, with the risk assessment software. Specifically, the deep‐water channel of the Yangtze River estuary was taken as an example to illustrate the general assessment procedure. The method proposed presents practical significance and application prospect on the maintenance and management of the aids to navigation.

Research on the Three-Dimensional Simulation and Emulation Technique of NC Machining Based on CORBA

This paper firstly analyzes traditional NC machining simulation technique and its flows. On this basis, it puts forward a method that implements NC machining three-dimensional simulation and emulation system architecture using distributed object CORBA component technology and OpenGL graphic technology [1,2], and details information about the model of this architecture, use Visual C++ as developer tool to implement NC machining simulation which is independent of platform and network.

Simulations and Analysis of the Moving Mask UV Lithography for Thick-Photoresist

A three-dimensional (3D) simulation system is developed for the moving mask UV lithography of thick photoresist. The exposure simulation model is obtained with consideration of the mask moving function, the refraction and energy loss of the UV light at the surface of photoresist, and the reflection at the photoresist/substrate interface. The development model is calculated by the fast marching method. In addition, the energy deposition distributions and the three-dimensional development profiles are presented under different conditions to study the effect of various parameters and to verify the accuracy by experiment. The results will be useful to understand the effects and to control the exposure conditions in the design process of moving mask UV lithography for thick-photoresist in the future.

Digital Urban Three-Dimensional Technique Base on OpenGL

With the fast development of computer multimedia technology, space technology, visualization technology, digital geomatics technology and computer graphics technology, using three-dimensional GIS technology to realize virtual visualization scene become reality. Three-dimensional GIS had already been applied to a lot of fields, such as country resource management, urban planning, public security system, electric power telecom branch. The paper had paid great attention to the popular three-dimensional GIS technology which had been in progress studying nowadays. It has summarized the research content and developed condition of current three-dimensional GIS and expatiates on the comprehensive application foreground of three-dimensional GIS. It had discussed and studied the three-dimensional GIS modeling method and the key visualization technology which based on OpenGL. It designed and realized a three-dimensional GIS simulation system. The paper had done the main studies as follows: (1) 3D GIS modeling theory and method had been discussed in this paper, and the paper had realized 3D modeling based on 3dsmax become reality; (2) It had designed and realized a three-dimensional GIS simulation system based on visualization technology which based on OpenGL.

OpenGL Based Collision Avoidance Technology in a Virtual Environment for Robot Path Planning Simulation

In order to improve the realism of virtual environments, in this paper, based on the software platform— VC++ and OpenGL, we combine complex modeling technology and fast rendering algorithm to establish a three-dimensional simulation system of the robot path planning scenario, which realize the collision requirements of virtual environment. All simulation results show that our collision avoidance technology can significantly improve the effect and the realistic of the robot path planning simulation in the virtual environment.

A Three-Dimensional Simulation System for Truck Crane Hoisting Based on Cloud Computing

Aiming at the problem of real-time calculation in the complex hoisting algorithm employed in the three-dimensional hoisting simulation system, this paper proposes a system based on cloud computing. First, the system structure based on cloud computing is designed. Then, to meet the requirements of the practical hoisting, the complex hoisting algorithms based on cloud computing are put forward, which involve collision detection, hoisting path planning, and so on. Finally, web publishing and complex computing in the background are realized by employing Browse/Server (B/S) structure and software Hadoop. The results show that the method proposed in this paper can improve the real-time calculation in the complex algorithms and achieve a smooth process of simulation.

A Three-Dimensional Virtual Simulation System of Spinning Production Line

This study takes a chemical fiber factory’s spinning production line as the prototype to realize a three-dimensional virtual simulation system. Geometric three-dimensional models are constructed by exploiting the image-based three dimension reconstruction technology, in which Harris algorithm is utilized to detect corners of the modeling objects. 3DSMAX is used to give each model a highly imitative material, and deploy panoramic lighting. For virtual interaction, OGRE is utilized to realize the roaming and interaction of the virtual scene, thus finally completes a virtual simulation system for the spinning production line. Experimental results show that the system achieves a high degree of simulation of three-dimensional virtual scene and gives the user great sense of immersion, which meet the needs of virtual reality.

The Research and Implementation of Three-dimensional Accident Simulation System in Substation

The Research and Implementation of Three-dimensional Accident Simulation System in Substation

Minimally-invasive open reduction of intracapsular condylar fractures with preoperative simulation using computer-aided design

Reduction of intracapsular condylar fractures is difficult, so we have based our technique on preoperative simulation using computer-aided design (CAD), which has proved useful in other surgical specialties. We have treated 11 patients with intracapsular condylar fractures. Before the operation the procedure was shown on the computer using a three-dimensional simulation system. The relation between the stump and the fragment of the condyle, and assessment of the position and the size of the screw, were made preoperatively to obtain a perfect fit. The displaced fragment was reduced by elevators, and fixed with a bicortical screw through a minimised preauricular incision under general anaesthesia. The fragments and the location of the screws were similar on the preoperative simulation and on the postoperative computed tomographic (CT) scan. The reduction and fixation of the fracture showed a perfect fit on the same view in the preoperative CAD simulation in the Mimics 10.01 software and postoperatively. Postoperative clinical examinations showed good occlusion and satisfactory mouth opening. Two patients had temporary paralysis of the occipitofrontalis muscle that recovered within 3 months. All patients regained normal mandibular movements and had short and invisible scars at 6 months’ follow up. The technique of CAD simulation could help to improve the accuracy during open treatment for intracapsular condylar fractures.

The Development and Research of the Three-Dimensional Simulation System of the Garments CAD

The development and research of three-dimensional (3D) simulation system of the garments CAD (Computer Aided Design) will change the traditional graphic design concepts and design methods, which will develop from two-dimensional (2D) to 3D. It means to build a comprehensive calculating methodology for forming real garments simulation system on the computer. Combining with the advanced CAD technology and technical works of Chinese garments industry will greatly improve the level of the sustainable development and intelligentialization of the software, and will accelerate the technical upgrade of modern garments industry and push the rapid development of national economy.

Multiple Linear Regression Model Based on Neural Network and Its Application in the MBR Simulation

The computer simulation of the membrane bioreactor MBR has become the research focus of the MBR simulation. In order to compensate for the defects, for example, long test period, high cost, invisible equipment seal, and so forth, on the basis of conducting in‐depth study of the mathematical model of the MBR, combining with neural network theory, this paper proposed a three‐dimensional simulation system for MBR wastewater treatment, with fast speed, high efficiency, and good visualization. The system is researched and developed with the hybrid programming of VC++ programming language and OpenGL, with a multifactor linear regression model of affecting MBR membrane fluxes based on neural network, applying modeling method of integer instead of float and quad tree recursion. The experiments show that the three‐dimensional simulation system, using the above models and methods, has the inspiration and reference for the future research and application of the MBR simulation technology.

Three-dimensional echocardiographic virtual endoscopy for the diagnosis of congenital heart disease in children

Virtual endoscopy (VE) is a new post-processing method that uses volumetric data sets to simulate the tracks of a “conventional” flexible endoscope. However, almost all studies of this method have involved virtual visualizations of the cardiovascular structures applied to computed tomography (CT) and magnetic resonance (MR) datasets. This paper introduces a novel visualization method called the “three-dimensional echocardiographic intracardiac endoscopic simulation system (3DE IESS)”, which uses 3D echocardiographic images in a virtual reality (VR) environment to diagnose congenital heart disease. The aim of this study was to analyze the feasibility of VE in the evaluation of congenital heart disease in children and its accuracy compared with 2DE. Three experienced pediatric cardiologists blinded to the patients’ diagnoses separately reviewed 40 two-dimensional echocardiographic (2DE) datasets and 40 corresponding VE datasets and judged whether abnormal intracardiac anatomy was present in terms of a five-point scale (1 = definitely absent; 2 = probably absent; 3 = cannot be determined; 4 = probably present; and 5 = definitely present). Compared with clinical diagnosis, the diagnostic accuracy of VE was 98.7% for ASD, 92.4% for VSD, 92.6% for TOF, and 94% for DORV, respectively. Diagnostic accuracy of VE was significantly higher than that of 2DE for TOF and DORV except for ASD and VSD. The receiver operating characteristic (ROC) curve for VE was closer to the optimal performance point than was the ROC curve for 2DE. The area under the ROC curve was 0.96 for VE and 0.93 for 2DE. Kappa values (range, 0.73–0.79) for VE and 2DE indicated substantial agreement. 3D echocardiographic VE can enhance our understanding of intracardiac structures and facilitate the evaluation of congenital heart disease.

Simulation of nucleation and growth stages for sputtered films

A three-dimensional simulation system of sputter deposition for microstructure evolution of thin films has been developed in this study. In terms of the nucleation stage, the nucleation process is modeled using a randomization method, which produces atomic data to describe the condition of nuclei coverage. In terms of the growth stage, the topographic evolution is modeled using level set methods, and the deposition rate is evaluated considering shadow effects. The effects of controlled nucleation variables (including sticking coefficients, captured radii of clusters and critical nuclei size) on nucleation types are discussed in the model as well as the influences of nucleation types on the following grain growth. The simulation results show that three different nucleation types (networks, flat pieces and islands) are observed for different combinations of controlled nucleation variables. Under the assumption of immobile grain boundaries, the resulting grain shapes and grain structures of these three nucleation types are different. The simulation results of nucleation and growth are also shown to be consistent with the experimental data of references.

Three-dimensional visualization simulation assessment system based on multi-source data fusion for the Wenchuan earthquake

We have developed a visual three-dimensional simulation and assessment system of the Wenchuan earthquake zone using the Digital Earth concept and highly efficient spatial information visualization technology. Our goal is to provide a foundation for earthquake disaster relief and reconstruction. A number of major collapses, landslides, mud-rock flows and other geological disasters are analysed in the system, and the system can be used to monitor and analyse earthquake relief, rescue and insurance to provide first-hand source material for disaster situation assessment. Multi-sensor, multi-temporal, multi-resolution remote sensing data and multi-scale DEM data are integrated into this system, and produce a sequence of comprehensive resolution datasets. We present management methods for a dynamic multi-resolution terrain model and multi-level scene. These methods are based on the model division, delaminating algorithm, and make use of high-speed buffering mechanisms to achieve a multi-level large-scale real-time rendering of scenes in the disaster areas, which also effectively reduces the rendering delay, and achieves smooth, seamless roaming at different model levels.

Surgical planning and simulation system for orthognathic surgery based on virtual reality

Background and Objectives: To establish a computer-assisted three-dimensional virtual surgical planning and simulation system for orthognathic surgery.

Experiencing Belugas: Action Selection for an Interactive Aquarium Exhibit

In this article we present a case study of an action-selection system designed with adaptive techniques to create a virtual beluga aquarium exhibit. The beluga interactive exhibit uses a realistic three-dimensional simulation system, which allows the virtual belugas, in a natural pod context, to learn and alter their behavior based on contextual visitor interaction. Ethogram information on beluga behavior was incorporated into the simulation, which uses physically based systems for natural whale locomotion and water, artificial intelligence systems including modified neural networks and a reactive hierarchical action-selection mechanism to simulate real-time natural individual beluga and group behavior. The beluga’s behavioral system consists of two layers: a low-level navigation system and a high-level reaction hierarchical action-selection system. The system is designed to be run on consumer level hardware while maintaining real-time speeds.

The process of arc splitting between metal plates in low voltage arc chutes

The behavior of arcs in low voltage switching devices is affected by several interactions. For studying simple arrangements of arc runners without metallic splitter plates (deion plates) a three-dimensional simulation system has already been developed. It takes into account the plasma fluid dynamics, the current flow within the electrodes and the plasma, and the magnetic field generated by both currents. In order to model the arc splitting process simulations with an insulating barrier were done in a first step. For the simulation of the splitting process between metallic deion-plates the simulation model has to be extended. In experiments including high-speed movies it is shown that this process is a continuous transition of current flow from the still undivided arc to the new arc roots formed on the metal plates. A new simulation model representing the roots by a thin layer of current-dependent resistivity is discussed and simulation results are compared with switching experiments

Three-Dimensional Modeling of Sediment and Phosphorus Dynamics in Lake Okeechobee, Florida: Spring 1989 Simulation

Lake Okeechobee is a large and shallow freshwater body in south Florida. Due to the shallowness of Lake Okeechobee, the nutrient dynamics are strongly influenced by hydrodynamic processes (circulation and wind-induced waves) and sediment transport processes. To study water quality and the effects of hydrodynamic and sediment transport processes on nutrient dynamics in the lake, a three-dimensional simulation system that closely couples hydrodynamic and sediment transport processes with nutrient dynamics was developed and used. In this paper, we present a three-dimensional, coupled hydrodynamics-sediment-nutrient model for Lake Okeechobee. The coupled model was used to simulate a four-week survey conducted in spring 1989 in Lake Okeechobee. By comparing model results to measured field data, it is shown that the coupled model system is able to simulate weekly sediment and phosphorus dynamics in Lake Okeechobee. Model applications demonstrated that the resuspension flux of phosphorus from the lake bottom is significantly higher than the molecular flux during resuspension events and can cause increases of phosphorus concentrations in the water column. Sensitivity runs of the model show that both the advective/diffusive transport and the algal uptake promote the release of phosphorus from suspended sediments and thus affect the phosphorus budget in the lake and the net resuspension flux of phosphorus from the lake bottom.

A numerical study of the effect of operating parameters on drop formation in a squeeze mode inkjet device

This study aims to investigate the ink droplet formation process of a squeeze mode piezoelectric printhead after an electrical pulse is applied by numerical analysis. The ink flow channel is modelled as a straight circular pipe ending in a convergent nozzle. The three-dimensional simulation system is based on the solution algorithm scheme for the solution of the governing equations of the flow field, and a volume-of-fluid method to predict the fluid interfaces is presented. The surface tension is modelled using a continuum surface force concept and thus computed as a function of the interfacial curvature. The pressure at the nozzle inlet, which is related to the applied voltage imposed on the simulation system, is determined by the propagation theory of acoustic waves. The effects of a pressure wave and cavity length on the droplet ejection process are presented.

Development of a three-dimensional simulation system for micro-inkjet and its experimental verification

A three-dimensional computer-aided analysis system has been developed in this study to simulate the formation, ejection, and impact of a liquid droplet in a squeeze-type piezoelectric inkjet printing device. The computer simulation system is based on a solution algorithm (SOLA) scheme for the solution of velocity and pressure fields. It is coupled with volume-of-fluid (VOF) and piecewise-linear interface construction (PLIC) techniques for the transport of F values, which are the volume fractions of liquid in the cells, and construction of the interface. For the treatment of surface tension effects, a CSF (continuum surface force) model is employed. The pressure at the nozzle inlet, which is related to the applied voltage, imposed on the simulation system is determined by the propagation theory of acoustic waves. The simulated results are rather consistent with the experimental observations in terms of droplet morphology, break-up time, flying distance, and droplet volume.