Driving a vehicle is one of the most common daily yet hazardous tasks. One of the great interests in recent research is to characterize a driver’s behaviors through the use of a driving simulation. Virtual reality te...Driving a vehicle is one of the most common daily yet hazardous tasks. One of the great interests in recent research is to characterize a driver’s behaviors through the use of a driving simulation. Virtual reality technology is now a promising alternative to the conventional driving simulations since it provides a more simple, secure and user-friendly environment for data collection. The driving simulator was used to assist novice drivers in learning how to drive in a very calm environment since the driving is not taking place on an actual road. This paper provides new insights regarding a driver’s behavior, techniques and adaptability within a driving simulation using virtual reality technology. The theoretical framework of this driving simulation has been designed using the Unity3D game engine (5.4.0f3 version) and programmed by the C# programming language. To make the driving simulation environment more realistic, the HTC Vive Virtual reality headset, powered by Steamvr, was used. 10 volunteers ranging from ages 19 - 37 participated in the virtual reality driving experiment. Matlab R2016b was used to analyze the data obtained from experiment. This research results are crucial for training drivers and obtaining insight on a driver’s behavior and characteristics. We have gathered diverse results for 10 drivers with different characteristics to be discussed in this study. Driving simulations are not easy to use for some users due to motion sickness, difficulties in adopting to a virtual environment. Furthermore, results of this study clearly show the performance of drivers is closely associated with individual’s behavior and adaptability to the driving simulator. Based on our findings, it can be said that with a VR-HMD (Virtual Reality-Head Mounted Display) Driving Simulator enables us to evaluate a driver’s “performance error”, “recognition errors” and “decision error”. All of which will allow researchers and further studies to potentially establish a method to increase driver safety or alleviate “driving errors”.展开更多
A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometr...A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometries (i.e. D-, △-, W- and U-shape electrodes) have been considered. The characteristics of the discharge current, the operating voltage and the discharge efficiency of different configurations have been discussed. It is found that the discharge efficiency can be improved by about 10%-30% compared with the standard geometry, while the operating voltage increases slightly in the non-standard geometries. There is a trade-off between improving the discharge efficiency and lowering the sustaining voltage in design of plasma display cells by electrode shaping.展开更多
Speeding in a work zone needs to be tackled effectively to enhance work zone safety. This study evaluates the influence of three different work zone signs—speed photo enforced signs, dynamic speed display signs and r...Speeding in a work zone needs to be tackled effectively to enhance work zone safety. This study evaluates the influence of three different work zone signs—speed photo enforced signs, dynamic speed display signs and reduced speed limit signs—on driver speeding behavior using a medium-fidelity driving simulator. The speed photo enforced and reduced speed limit signs were placed at intervals before the start of the work zone and in the work zone. A virtual work zone network was built to replicate the Baltimore–Washington Parkway(MD-295). A total of 66 participants from different socioeconomic backgrounds participated in 264 driving simulation sessions. The speeds were measured over four phases: initial speed area, sign visible area, sign readable area and post sign area. An analysis of variance and post hoc analysis showed that the speed photo enforced sign was the most effective of the three signs. The second speed photo enforced sign within the work zone was more effective at reducing speed than the sign before the start of the work zone, especially in the post sign area. It was observed that female participants tend to slow down more when encountering a speed photo enforcement sign.展开更多
A new type of AC PDP(alternating current plasma display panel) cell with a five-electrode structure is developed to improve the luminous efficiency of AC PDP.The discharge efficiency of this new cell structure is inve...A new type of AC PDP(alternating current plasma display panel) cell with a five-electrode structure is developed to improve the luminous efficiency of AC PDP.The discharge efficiency of this new cell structure is investigated by a 2D fluid simulation. Continuity equations and flux density equations for charged particles and excited atoms, energy balance equation for electrons are included in the model. The discharge gas is He+5%Xe. The reactions of ionization, excitation, recombination, and radiation are taken into account. The vacuum ultraviolet radiation efficiency of the five-electrode cell structure is about 20% higher than that of a conventional three-electrode cell structure.展开更多
Background Due to the restriction of display mode,in most of the virtual reality systems with multiple people in the same physical space,the program renders the scene based on the position and perspective of the one u...Background Due to the restriction of display mode,in most of the virtual reality systems with multiple people in the same physical space,the program renders the scene based on the position and perspective of the one user,so that other users just see the same scene,resulting in vision disorder.Methods To improve experience of multi-user co-located collaboration,in this study,we propose a fire drill system supporting co-located collaboration,in which three co-located users can collaborate to complete the virtual firefighting mission.Firstly,with multi-view stereoscopic projective display technology and ultra wideband(UWB)technology,co-located users can roam independently and watch virtual scenes through the correct perspective view based on their own position by wearing dedicated shutter glasses,thus carrying out different virtual tasks,which improves the flexibility of co-located collaboration.Secondly,we design simulated firefighting water-gun using the micro-electromechanical system sensor,through which users can interact with virtual environment,and thus provide a better interactive experience.Finally,we develop a workbench including a holographic display module and multi touch operation module for virtual scene assembly and virtual environment control.Results The controller can use the workbench to adjust the virtual layout in real time,and control the virtual task process to increase the flexibility and playability of system.Conclusions Our work can be employed in a wide range of related virtual reality applications.展开更多
A pioneer research work was carried out by investigators engaged in surveying and mapping for describing ancient Chinese timber buildings by 3D frame graphs with a computer.Users can know the structural layers and the...A pioneer research work was carried out by investigators engaged in surveying and mapping for describing ancient Chinese timber buildings by 3D frame graphs with a computer.Users can know the structural layers and the assembly process of these buildings if the frame graphs are processed further with a computer model.This can be implemented by computer simulation technique.This technique display the raw data on the screen of a computer and interactively manage them by combining technologies from computer graphics and image processing,multi-media technology,artificial intelligence,highly parallel real-time computation technique and human behavior science.This paper presents the implementing procedure of lignification simulation for large-sized wooden buildings as well as 3D dynamic assembly of these buildings under the 3DS MAX environment.The results from computer simulation are also shown in the paper.展开更多
Microstructural evolutions of ceramic grain growth we re dynamically demonstrated with 3D graphical display techniques. Based on the p rinciples of grain growth in ceramics, the data of coordination in different ato m...Microstructural evolutions of ceramic grain growth we re dynamically demonstrated with 3D graphical display techniques. Based on the p rinciples of grain growth in ceramics, the data of coordination in different ato ms were calculated with Monte-Carlo method at atomistic scale. Realistic images in three-dimension were displayed onto two-dimension monitor by projection, i llumination and atomization, using Visual C++ and OpenGL languages. Different small spheres were used to model different kind of atoms, which filled within a fictitious cube. The radius and coordination for different atoms were then determined according to corresponding ratios by using of perspective projec tion of OpenGL languages. The applications of illuminating, texturizing and at omization techniques enhanced greatly the stereo effect of images.展开更多
In this paper, the mathematical and physical model was developed based on thermodynamics and solidification theory before the eutectoid transformation of nodular graphite iron occurred. The Local Element Substitute an...In this paper, the mathematical and physical model was developed based on thermodynamics and solidification theory before the eutectoid transformation of nodular graphite iron occurred. The Local Element Substitute and Magnification Method was brought forward and 3-dimensional numerical simulation program based on the model and the new assistant algorithm was developed and used to calculate the samples. Results of calculation have good agreement with experimental data. To display the microstructure formation during solidification of nodular graphite iron, a 2-dimensional numerical simulation program combined with the result of the 3-dimensional numerical simulation of experimental samples was compiled.展开更多
Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered t...Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered to improve the design, as the CDI must provide enough SA for the pilot to maintain the flight safety. In order to study the SA in the pilot-aircraft system, a cockpit flight simulation environment is built up, which includes a virtual instrument panel, a flight visual display and the corresponding control system. Based on the simulation environment, a human-in-the-loop experiment is designed to measure the SA by the situation awareness global assessment technique (SAGAT). Through the experiment, the SA degrees and heart rate (HR) data of the subjects are obtained, and the SA levels under different CDI designs are analyzed. The results show that analyzing the SA can serve as an objective way to evaluate the design of CDI, which could be proved from the consistent HR data. With this method, evaluations of the CDI design are performed in the experimental flight simulation environment, and optimizations could be guided through the analysis.展开更多
2010320 3D visualization for simulating percutaneous transcatheter closure of atrial septal defect:a pilot clinical study. HONG Wenjing(洪雯静),et al. Dept Pediatr Cardiol,Shanghai Children’s Med Center,Med Sch,...2010320 3D visualization for simulating percutaneous transcatheter closure of atrial septal defect:a pilot clinical study. HONG Wenjing(洪雯静),et al. Dept Pediatr Cardiol,Shanghai Children’s Med Center,Med Sch,Shanghai Jiaotong Univ,Shanghai 200127.Chin J Cardiol 2010;38(4):330-333. Objective To evaluate the clinical value of 3D visualization method展开更多
文摘Driving a vehicle is one of the most common daily yet hazardous tasks. One of the great interests in recent research is to characterize a driver’s behaviors through the use of a driving simulation. Virtual reality technology is now a promising alternative to the conventional driving simulations since it provides a more simple, secure and user-friendly environment for data collection. The driving simulator was used to assist novice drivers in learning how to drive in a very calm environment since the driving is not taking place on an actual road. This paper provides new insights regarding a driver’s behavior, techniques and adaptability within a driving simulation using virtual reality technology. The theoretical framework of this driving simulation has been designed using the Unity3D game engine (5.4.0f3 version) and programmed by the C# programming language. To make the driving simulation environment more realistic, the HTC Vive Virtual reality headset, powered by Steamvr, was used. 10 volunteers ranging from ages 19 - 37 participated in the virtual reality driving experiment. Matlab R2016b was used to analyze the data obtained from experiment. This research results are crucial for training drivers and obtaining insight on a driver’s behavior and characteristics. We have gathered diverse results for 10 drivers with different characteristics to be discussed in this study. Driving simulations are not easy to use for some users due to motion sickness, difficulties in adopting to a virtual environment. Furthermore, results of this study clearly show the performance of drivers is closely associated with individual’s behavior and adaptability to the driving simulator. Based on our findings, it can be said that with a VR-HMD (Virtual Reality-Head Mounted Display) Driving Simulator enables us to evaluate a driver’s “performance error”, “recognition errors” and “decision error”. All of which will allow researchers and further studies to potentially establish a method to increase driver safety or alleviate “driving errors”.
基金Project supported by the National Natural Science Foundation of China (Grant No 10475007), the Scientific Research Foundation for the Returned 0verseas Chinese Scholars, the State Education Ministry of China (Grant No LLKYJJ200403) and Thomson . Plasma, France.
文摘A macroscopic cell and three-dimensional fluid model have been used to investigate the discharge characteristics in ac plasma display panel cells of electrode-shaping configurations. Four kinds of non-standaxd geometries (i.e. D-, △-, W- and U-shape electrodes) have been considered. The characteristics of the discharge current, the operating voltage and the discharge efficiency of different configurations have been discussed. It is found that the discharge efficiency can be improved by about 10%-30% compared with the standard geometry, while the operating voltage increases slightly in the non-standard geometries. There is a trade-off between improving the discharge efficiency and lowering the sustaining voltage in design of plasma display cells by electrode shaping.
基金the Maryland State Highway Association (SHA) for its funding support throughout the study
文摘Speeding in a work zone needs to be tackled effectively to enhance work zone safety. This study evaluates the influence of three different work zone signs—speed photo enforced signs, dynamic speed display signs and reduced speed limit signs—on driver speeding behavior using a medium-fidelity driving simulator. The speed photo enforced and reduced speed limit signs were placed at intervals before the start of the work zone and in the work zone. A virtual work zone network was built to replicate the Baltimore–Washington Parkway(MD-295). A total of 66 participants from different socioeconomic backgrounds participated in 264 driving simulation sessions. The speeds were measured over four phases: initial speed area, sign visible area, sign readable area and post sign area. An analysis of variance and post hoc analysis showed that the speed photo enforced sign was the most effective of the three signs. The second speed photo enforced sign within the work zone was more effective at reducing speed than the sign before the start of the work zone, especially in the post sign area. It was observed that female participants tend to slow down more when encountering a speed photo enforcement sign.
基金The project supported by 2002 project for Science and Technology of Ministry of Education
文摘A new type of AC PDP(alternating current plasma display panel) cell with a five-electrode structure is developed to improve the luminous efficiency of AC PDP.The discharge efficiency of this new cell structure is investigated by a 2D fluid simulation. Continuity equations and flux density equations for charged particles and excited atoms, energy balance equation for electrons are included in the model. The discharge gas is He+5%Xe. The reactions of ionization, excitation, recombination, and radiation are taken into account. The vacuum ultraviolet radiation efficiency of the five-electrode cell structure is about 20% higher than that of a conventional three-electrode cell structure.
基金National Key Research and Development Program of China(2018YFC0831003)Key R&D project of Shandong Province(2016GGX106001).
文摘Background Due to the restriction of display mode,in most of the virtual reality systems with multiple people in the same physical space,the program renders the scene based on the position and perspective of the one user,so that other users just see the same scene,resulting in vision disorder.Methods To improve experience of multi-user co-located collaboration,in this study,we propose a fire drill system supporting co-located collaboration,in which three co-located users can collaborate to complete the virtual firefighting mission.Firstly,with multi-view stereoscopic projective display technology and ultra wideband(UWB)technology,co-located users can roam independently and watch virtual scenes through the correct perspective view based on their own position by wearing dedicated shutter glasses,thus carrying out different virtual tasks,which improves the flexibility of co-located collaboration.Secondly,we design simulated firefighting water-gun using the micro-electromechanical system sensor,through which users can interact with virtual environment,and thus provide a better interactive experience.Finally,we develop a workbench including a holographic display module and multi touch operation module for virtual scene assembly and virtual environment control.Results The controller can use the workbench to adjust the virtual layout in real time,and control the virtual task process to increase the flexibility and playability of system.Conclusions Our work can be employed in a wide range of related virtual reality applications.
文摘A pioneer research work was carried out by investigators engaged in surveying and mapping for describing ancient Chinese timber buildings by 3D frame graphs with a computer.Users can know the structural layers and the assembly process of these buildings if the frame graphs are processed further with a computer model.This can be implemented by computer simulation technique.This technique display the raw data on the screen of a computer and interactively manage them by combining technologies from computer graphics and image processing,multi-media technology,artificial intelligence,highly parallel real-time computation technique and human behavior science.This paper presents the implementing procedure of lignification simulation for large-sized wooden buildings as well as 3D dynamic assembly of these buildings under the 3DS MAX environment.The results from computer simulation are also shown in the paper.
文摘Microstructural evolutions of ceramic grain growth we re dynamically demonstrated with 3D graphical display techniques. Based on the p rinciples of grain growth in ceramics, the data of coordination in different ato ms were calculated with Monte-Carlo method at atomistic scale. Realistic images in three-dimension were displayed onto two-dimension monitor by projection, i llumination and atomization, using Visual C++ and OpenGL languages. Different small spheres were used to model different kind of atoms, which filled within a fictitious cube. The radius and coordination for different atoms were then determined according to corresponding ratios by using of perspective projec tion of OpenGL languages. The applications of illuminating, texturizing and at omization techniques enhanced greatly the stereo effect of images.
文摘In this paper, the mathematical and physical model was developed based on thermodynamics and solidification theory before the eutectoid transformation of nodular graphite iron occurred. The Local Element Substitute and Magnification Method was brought forward and 3-dimensional numerical simulation program based on the model and the new assistant algorithm was developed and used to calculate the samples. Results of calculation have good agreement with experimental data. To display the microstructure formation during solidification of nodular graphite iron, a 2-dimensional numerical simulation program combined with the result of the 3-dimensional numerical simulation of experimental samples was compiled.
基金supported by National Basic Research Program of China(No.2010CB734104)
文摘Aircraft cockpit display interface (CDI) is one of the most important human-machine interfaces for information perceiving. During the process of aircraft design, situation awareness (SA) is frequently considered to improve the design, as the CDI must provide enough SA for the pilot to maintain the flight safety. In order to study the SA in the pilot-aircraft system, a cockpit flight simulation environment is built up, which includes a virtual instrument panel, a flight visual display and the corresponding control system. Based on the simulation environment, a human-in-the-loop experiment is designed to measure the SA by the situation awareness global assessment technique (SAGAT). Through the experiment, the SA degrees and heart rate (HR) data of the subjects are obtained, and the SA levels under different CDI designs are analyzed. The results show that analyzing the SA can serve as an objective way to evaluate the design of CDI, which could be proved from the consistent HR data. With this method, evaluations of the CDI design are performed in the experimental flight simulation environment, and optimizations could be guided through the analysis.
文摘2010320 3D visualization for simulating percutaneous transcatheter closure of atrial septal defect:a pilot clinical study. HONG Wenjing(洪雯静),et al. Dept Pediatr Cardiol,Shanghai Children’s Med Center,Med Sch,Shanghai Jiaotong Univ,Shanghai 200127.Chin J Cardiol 2010;38(4):330-333. Objective To evaluate the clinical value of 3D visualization method