Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D onli...Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D online tourism, Web3D online architecture, Web3D online education environment, Web3D online medical care, and Web3D online shopping are examples of these applications that leverage 3D rendering on the web. These applications have pushed the boundaries of traditional web applications that use text, sound, image, video, and 2D animation as their main communication media, and resorted to 3D virtual scenes as the main interaction object, enabling a user experience that delivers a strong sense of immersion. This paper approached the emerging Web3D applications that generate stronger impacts on people's lives through “real-time rendering technology”, which is the core technology of Web3D. This paper discusses all the major 3D graphics APIs of Web3D and the well-known Web3D engines at home and abroad and classify the real-time rendering frameworks of Web3D applications into different categories. Results Finally, this study analyzed the specific demand posed by different fields to Web3D applications by referring to the representative Web3D applications in each particular field. Conclusions Our survey results show that Web3D applications based on real-time rendering have in-depth sectors of society and even family, which is a trend that has influence on every line of industry.展开更多
Simulation and rendering of large-scale natural environments, especially the ocean, has always been one of the hot issues in computer graphics, which can provide realism for various applications such as computer game,...Simulation and rendering of large-scale natural environments, especially the ocean, has always been one of the hot issues in computer graphics, which can provide realism for various applications such as computer game, movie and military usage. Simulation of ocean environment is often lack of realism for real-time application due to its complexity of dynamic waves. In this paper, a method based on FFT Wave model is proposed to solve this problem, which can also simulate the ocean optic property with atmosphere scattering. Furthermore, our method has a lot of advantages including global ocean dataset support, real-time, dynamic reflection of ocean, the foam on the wave, smooth transition from deep ocean to seacoast, etc. The experimental results demonstrate the realism and effectiveness of our approach.展开更多
The multi-resolution adaptive grids method is proposed to solve the problems of inefficiency in the previous grid-based methods,and it can be used in clouds simulation as well as the interactive simulation between obj...The multi-resolution adaptive grids method is proposed to solve the problems of inefficiency in the previous grid-based methods,and it can be used in clouds simulation as well as the interactive simulation between objects and clouds.Oriented bounding box(OBB)hierarchical trees of objects are established,and the resolutions of global and local grids can be selected automatically.The motion equations of fluid dynamics are simplified.Upwind difference is applied to ensure the stability of the simulation process during the discrete process of partial differential equations.To solve the speed problem of existed phase functions,the improved phase function is applied to the illumination calculation of clouds.Experimental results show that the proposed methods can promote the simulation efficiency and meet the need for the simulation of large-scale clouds scene.Real-time rendering of clouds and the interaction between clouds and objects have been realized without preprocessing stage.展开更多
Background Realistic rendering has been an important g oal of several interactive applications,which requires an efficient virtual simulation of many special effects that are common in the real world.However,refractio...Background Realistic rendering has been an important g oal of several interactive applications,which requires an efficient virtual simulation of many special effects that are common in the real world.However,refraction is often ignored in these applications.Rendering the refraction effect is extremely complicated and time-consuming.Methods In this study,a simple,efficient,and fast rendering technique of water refraction effects is proposed.This technique comprises a broad and narrow phase.In the broad phase,the water surface is considered flat.The vertices of underwater meshes are transformed based on Snell's Law.In the narrow phase,the effects of waves on the water surface are examined.Every pixel on the water surface mesh is collected by a screen-space method with an extra rendering pass.The broad phase redirects most pixels that need to be recalculated in the narrow phase to the pixels in the rendering buffer.Results We analyzed the performances of three different conventional methods and ours in rendering refraction effects for the same scenes.The proposed method obtains higher frame rate and physical accuracy comparing with other methods.It is used in several game scenes,and realistic water refraction effects can be generated efficiently.Conclusions The two-phase water refraction method produces a tradeoff between efficiency and quality.It is easy to implement in modern game engines,and thus improve the quality of rendering scenes in video games or other real-ti me applications.展开更多
In virtual simulation application, it is often necessary to use Open GL to render large-scale 3D static scenes including urban architectures. Each scene unit generally has individual vertex data and texture. For large...In virtual simulation application, it is often necessary to use Open GL to render large-scale 3D static scenes including urban architectures. Each scene unit generally has individual vertex data and texture. For large-scale data set, it is hard to render all scene units simultaneously. We need to render part of the scene separately, which is called the scene partition and culling. In general, we partition the whole scene into different units on the CPU. We present a scheme that optimize the GPU rendering pipeline to cull the large-scale static scene, which will reduce the CPU suspending time and take full advantage of GPU computing advantages to speed up the rendering efficiency.展开更多
This paper presents an optimization of shadow volume algorithm, which allow a rendering in real-time. This technique is based on previous works which makes it possible to obtain shadows in real-time, although the calc...This paper presents an optimization of shadow volume algorithm, which allow a rendering in real-time. This technique is based on previous works which makes it possible to obtain shadows in real-time, although the calculation of the silhouette requires a pretreatment of the geometry implemented on the CPU (Central Processing Unit). By using last version of the GPU (Graphic Processing Unit), the authors propose to implement the calculation of the silhouette on the GPU by using Geometry Shader. The authors present the step which made it possible to lead to a concrete implementation of this algorithm, the modifications which were made, as well as a comparative study of results, followed by a discussion of these results and choices of implementation.展开更多
Real-time rendering applications leverage heterogeneous computing to optimize performance.However,software development across multiple devices presents challenges,including data layout inconsistencies,synchronization ...Real-time rendering applications leverage heterogeneous computing to optimize performance.However,software development across multiple devices presents challenges,including data layout inconsistencies,synchronization issues,resource management complexities,and architectural disparities.Additionally,the creation of such systems requires verbose and unsafe programming models.Recent developments in domain-specific and unified shading languages aim to mitigate these issues.Yet,current programming models primarily address data layout consistency,neglecting other persistent challenges.In this paper,we introduce RenderKernel,a programming model designed to simplify the development of real-time rendering systems.Recognizing the need for a high-level approach,RenderKernel addresses the specific challenges of real-time rendering,enabling development on heterogeneous systems as if they were homogeneous.This model allows for early detection and prevention of errors due to system heterogeneity at compile-time.Furthermore,RenderKernel enables the use of common programming patterns from homogeneous environments,freeing developers from the complexities of underlying heterogeneous systems.Developers can focus on coding unique application features,thereby enhancing productivity and reducing the cognitive load associated with real-time rendering system development.展开更多
This paper reports the recent works and progress on a PC and C++ language-based virtual auditory environment(VAE) system platform.By tracing the temporary location and orientation of listener's head and dynamicall...This paper reports the recent works and progress on a PC and C++ language-based virtual auditory environment(VAE) system platform.By tracing the temporary location and orientation of listener's head and dynamically simulating the acoustic propagation from sound source to two ears,the system is capable of recreating free-field virtual sources at various directions and distances as well as auditory perception in reflective environment via headphone presentation.Schemes for improving VAE performance,including PCA-based(principal components analysis) near-field virtual source synthesis,simulating six degrees of freedom of head movement,are proposed.Especially,the PCA-based scheme greatly reduces the computational cost of multiple virtual sources synthesis.Test demonstrates that the system exhibits improved performances as compared with some existing systems.It is able to simultaneously render up to 280 virtual sources using conventional scheme,and 4500 virtual sources using the PCA-based scheme.A set of psychoacoustic experiments also validate the performance of the system,and at the same time,provide some preliminary results on the research of binaural hearing.The functions of the VAE system is being extended and the system serves as a flexible and powerful platform for future binaural hearing researches and virtual reality applications.展开更多
Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this devic...Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this device,the complete shearedeformation process and long-term shear creep tests could be performed on rocks under constant normal stiffness(CNS)or constant normal loading(CNL)conditions in real-time at high temperature and true-triaxial stress.During the research and development process,five key technologies were successfully broken through:(1)the ability to perform true-triaxial compressioneshear loading tests on rock samples with high stiffness;(2)a shear box with ultra-low friction throughout the entire stress space of the rock sample during loading;(3)a control system capable of maintaining high stress for a long time and responding rapidly to the brittle fracture of a rock sample as well;(4)a refined ability to measure the volumetric deformation of rock samples subjected to true triaxial shearing;and(5)a heating system capable of maintaining uniform heating of the rock sample over a long time.By developing these technologies,loading under high true triaxial stress conditions was realized.The apparatus has a maximum normal stiffness of 1000 GPa/m and a maximum operating temperature of 300C.The differences in the surface temperature of the sample are constant to within5C.Five types of true triaxial shear tests were conducted on homogeneous sandstone to verify that the apparatus has good performance and reliability.The results show that temperature,lateral stress,normal stress and time influence the shear deformation,failure mode and strength of the sandstone.The novel apparatus can be reliably used to conduct true-triaxial shear tests on rocks subjected to high temperatures and stress.展开更多
Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxi...Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was conducted.Full-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.展开更多
This paper proposes a lightweight bidirectional scattering distribution function(BSDF)model for layered materials with anisotropic reflection and refraction properties.In our method,each layer of the materials can be ...This paper proposes a lightweight bidirectional scattering distribution function(BSDF)model for layered materials with anisotropic reflection and refraction properties.In our method,each layer of the materials can be described by a microfacet BSDF using an anisotropic normal distribution function(NDF).Furthermore,the NDFs of layers can be defined on tangent vector fields,which differ from layer to layer.Our method is based on a previous study in which isotropic BSDFs are approximated by projecting them onto base planes.However,the adequateness of this previous work has not been well investigated for anisotropic BSDFs.In this paper,we demonstrate that the projection is also applicable to anisotropic BSDFs and that the BSDFs are approximated by elliptical distributions using covariance matrices.展开更多
A real-time data processing system is designed for the carbon dioxide dispersion interferometer(CO_(2)-DI)on EAST.The system utilizes the parallel and pipelining capabilities of an fieldprogrammable gate array(FPGA)to...A real-time data processing system is designed for the carbon dioxide dispersion interferometer(CO_(2)-DI)on EAST.The system utilizes the parallel and pipelining capabilities of an fieldprogrammable gate array(FPGA)to digitize and process the intensity of signals from the detector.Finally,the real-time electron density signals are exported through a digital-to-analog converter(DAC)module in the form of analog signals.The system has been successfully applied in the CO_(2)-DI system to provide low-latency electron density input to the plasma control system on EAST.Experimental results of the latest campaign with long-pulse discharges on EAST(2022–2023)demonstrate that the system can respond effectively in the case of rapid density changes,proving its reliability and accuracy for future electron density calculation.展开更多
The co-frequency vibration fault is one of the common faults in the operation of rotating equipment,and realizing the real-time diagnosis of the co-frequency vibration fault is of great significance for monitoring the...The co-frequency vibration fault is one of the common faults in the operation of rotating equipment,and realizing the real-time diagnosis of the co-frequency vibration fault is of great significance for monitoring the health state and carrying out vibration suppression of the equipment.In engineering scenarios,co-frequency vibration faults are highlighted by rotational frequency and are difficult to identify,and existing intelligent methods require more hardware conditions and are exclusively time-consuming.Therefore,Lightweight-convolutional neural networks(LW-CNN)algorithm is proposed in this paper to achieve real-time fault diagnosis.The critical parameters are discussed and verified by simulated and experimental signals for the sliding window data augmentation method.Based on LW-CNN and data augmentation,the real-time intelligent diagnosis of co-frequency is realized.Moreover,a real-time detection method of fault diagnosis algorithm is proposed for data acquisition to fault diagnosis.It is verified by experiments that the LW-CNN and sliding window methods are used with high accuracy and real-time performance.展开更多
At present,debris flow warning uses precipitation threshold and issues regional warning throughout the world.Precipitation threshold warning is less accurate and in most of the time large portion of unaffected populat...At present,debris flow warning uses precipitation threshold and issues regional warning throughout the world.Precipitation threshold warning is less accurate and in most of the time large portion of unaffected population are evacuated.More precise warning should use direct monitoring.There are many debris flow monitoring stations but no real time warning system in use.The main reason is that the identification and confirmation of debris flow occurrence requires human interaction and it is too slow.A debris flow monitoring and warning system has been installed in the midstream section of Yusui Stream,Taiwan China.The monitoring station operates fully automatically,providing early warnings without the need for manual intervention.The system comprises two webcam cameras,two Micro-Electro-Mechanical Systems(MEMS),and a rain gauge.The arrival of debris flows is detected and confirmed through both webcam images and MEMS signals.Once debris flow is detected,the system automatically issues a warning to the affected areas via voice messages,line messages,broadcasts,and web-based alerts.The webcam cameras are also used to estimate debris flow velocity and flow height,while the MEMS sensors are utilized to determine the phase speed and flow rate.On July 24th,2014,Typhoon Gaemi triggered several debris flows,and the system successfully issued several warnings automatically.The entire video record,along with depth variation data,was recorded automatically.展开更多
This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In additio...This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In addition,examines key strategies for designing glucose sensors that are multi-functional,reliable,and cost-effective in a variety of contexts.The unique features of effective diabetes management technology are highlighted,with a focus on using nano/biosensor devices that can quickly and accurately detect glucose levels in the blood,improving patient treatment and control of potential diabetes-related infections.The potential of next-generation wearable and touch-sensitive nano biomedical sensor engineering designs for providing full control in assessing implantable,continuous glucose monitoring is also explored.The challenges of standardizing drug or insulin delivery doses,low-cost,real-time detection of increased blood sugar levels in diabetics,and early digital health awareness controls for the adverse effects of injectable medication are identified as unmet needs.Also,the market for biosensors is expected to expand significantly due to the rising need for portable diagnostic equipment and an ever-increasing diabetic population.The paper concludes by emphasizing the need for further research and development of glucose biosensors to meet the stringent requirements for sensitivity and specificity imposed by clinical diagnostics while being cost-effective,stable,and durable.展开更多
To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a sys...To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a system.First,we employ a strategy that restricts long-and short-term power output deviations to smoothen wind power fluctuations in real time.Second,we adopt the sliding window instantaneous complete ensemble empirical mode decomposition with adaptive noise(SW-ICEEMDAN)strategy to achieve real-time decomposition of the energy storage power,facilitating internal power distribution within the hybrid energy storage system.Finally,we introduce a rule-based multi-fuzzy control strategy for the secondary adjustment of the initial power allocation commands for different energy storage components.Through simulation validation,we demonstrate that the proposed comprehensive control strategy can smoothen wind power fluctuations in real time and decompose energy storage power.Compared with traditional empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD),and complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)decomposition strategies,the configuration of the energy storage system under the SW-ICEEMDAN control strategy is more optimal.Additionally,the state-of-charge of energy storage components fluctuates within a reasonable range,enhancing the stability of the power system and ensuring the secure operation of the energy storage system.展开更多
The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-r...The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.展开更多
The composite time scale(CTS)provides a stable,accurate,and reliable time scale for modern society.The improvement of CTS’s real-time performance will improve its stability,which strengths related applications’perfo...The composite time scale(CTS)provides a stable,accurate,and reliable time scale for modern society.The improvement of CTS’s real-time performance will improve its stability,which strengths related applications’performance.Aiming at this goal,a method achieved by determining the optimal calculation interval and accelerating adjustment stage is proposed in this paper.The determinants of the CTS’s calculation interval(characteristics of the clock ensemble,the measurement noise,the time and frequency synchronization system’s noise and the auxiliary output generator noise floor)are studied and the optimal calculation interval is obtained.We also investigate the effect of ensemble algorithm’s initial parameters on the CTS’s adjustment stage.A strategy to get the reasonable initial parameters of ensemble algorithm is designed.The results show that the adjustment stage can be finished rapidly or even can be shorten to zero with reasonable initial parameters.On this basis,we experimentally generate a distributed CTS with a calculation interval of 500 s and its stability outperforms those of the member clocks when the averaging time is longer than1700 s.The experimental result proves that the CTS’s real-time performance is significantly improved.展开更多
基金the Science and Technology Program of Educational Commission of Jiangxi Province,China(DA202104172)the Innovation and Entrepreneurship Course Program of Nanchang Hangkong University(KCPY1910)the Teaching Reform Research Program of Nanchang Hangkong University(JY21040).
文摘Background In recent years, with the rapid development of mobile Internet and Web3D technologies, a large number of web-based online 3D visualization applications have emerged. Web3D applications, including Web3D online tourism, Web3D online architecture, Web3D online education environment, Web3D online medical care, and Web3D online shopping are examples of these applications that leverage 3D rendering on the web. These applications have pushed the boundaries of traditional web applications that use text, sound, image, video, and 2D animation as their main communication media, and resorted to 3D virtual scenes as the main interaction object, enabling a user experience that delivers a strong sense of immersion. This paper approached the emerging Web3D applications that generate stronger impacts on people's lives through “real-time rendering technology”, which is the core technology of Web3D. This paper discusses all the major 3D graphics APIs of Web3D and the well-known Web3D engines at home and abroad and classify the real-time rendering frameworks of Web3D applications into different categories. Results Finally, this study analyzed the specific demand posed by different fields to Web3D applications by referring to the representative Web3D applications in each particular field. Conclusions Our survey results show that Web3D applications based on real-time rendering have in-depth sectors of society and even family, which is a trend that has influence on every line of industry.
基金Supported by National Natural Science Foundation of China(Nos.6117020561472010 and 61421062)+2 种基金National Key Technology Support Program(No.2013BAK03B07)National Key Technology R&D Program(2015BAK01B06)Shenzhen Gov Projects(JCYJ20130331144416448)
文摘Simulation and rendering of large-scale natural environments, especially the ocean, has always been one of the hot issues in computer graphics, which can provide realism for various applications such as computer game, movie and military usage. Simulation of ocean environment is often lack of realism for real-time application due to its complexity of dynamic waves. In this paper, a method based on FFT Wave model is proposed to solve this problem, which can also simulate the ocean optic property with atmosphere scattering. Furthermore, our method has a lot of advantages including global ocean dataset support, real-time, dynamic reflection of ocean, the foam on the wave, smooth transition from deep ocean to seacoast, etc. The experimental results demonstrate the realism and effectiveness of our approach.
基金supported by the National Natural Science Foundation of China(No.61102167)
文摘The multi-resolution adaptive grids method is proposed to solve the problems of inefficiency in the previous grid-based methods,and it can be used in clouds simulation as well as the interactive simulation between objects and clouds.Oriented bounding box(OBB)hierarchical trees of objects are established,and the resolutions of global and local grids can be selected automatically.The motion equations of fluid dynamics are simplified.Upwind difference is applied to ensure the stability of the simulation process during the discrete process of partial differential equations.To solve the speed problem of existed phase functions,the improved phase function is applied to the illumination calculation of clouds.Experimental results show that the proposed methods can promote the simulation efficiency and meet the need for the simulation of large-scale clouds scene.Real-time rendering of clouds and the interaction between clouds and objects have been realized without preprocessing stage.
基金the Fundamental Research Funds for the Central Universities,the National Key R&D Program of China(2018 YFB 1403900)the High-quality and Cutting-edge Disciplines Construction Project for Universities in Beijing(Internet Information,Communication University of China).
文摘Background Realistic rendering has been an important g oal of several interactive applications,which requires an efficient virtual simulation of many special effects that are common in the real world.However,refraction is often ignored in these applications.Rendering the refraction effect is extremely complicated and time-consuming.Methods In this study,a simple,efficient,and fast rendering technique of water refraction effects is proposed.This technique comprises a broad and narrow phase.In the broad phase,the water surface is considered flat.The vertices of underwater meshes are transformed based on Snell's Law.In the narrow phase,the effects of waves on the water surface are examined.Every pixel on the water surface mesh is collected by a screen-space method with an extra rendering pass.The broad phase redirects most pixels that need to be recalculated in the narrow phase to the pixels in the rendering buffer.Results We analyzed the performances of three different conventional methods and ours in rendering refraction effects for the same scenes.The proposed method obtains higher frame rate and physical accuracy comparing with other methods.It is used in several game scenes,and realistic water refraction effects can be generated efficiently.Conclusions The two-phase water refraction method produces a tradeoff between efficiency and quality.It is easy to implement in modern game engines,and thus improve the quality of rendering scenes in video games or other real-ti me applications.
基金Supported by National Key Technology Research and Development Program of China(2013BAK03B07)National Natural Science Foundation of China(61232014,61421062,61173080,61472010)+1 种基金National Marine public service project(201505014)Equipment Development project(315050501)
文摘In virtual simulation application, it is often necessary to use Open GL to render large-scale 3D static scenes including urban architectures. Each scene unit generally has individual vertex data and texture. For large-scale data set, it is hard to render all scene units simultaneously. We need to render part of the scene separately, which is called the scene partition and culling. In general, we partition the whole scene into different units on the CPU. We present a scheme that optimize the GPU rendering pipeline to cull the large-scale static scene, which will reduce the CPU suspending time and take full advantage of GPU computing advantages to speed up the rendering efficiency.
文摘This paper presents an optimization of shadow volume algorithm, which allow a rendering in real-time. This technique is based on previous works which makes it possible to obtain shadows in real-time, although the calculation of the silhouette requires a pretreatment of the geometry implemented on the CPU (Central Processing Unit). By using last version of the GPU (Graphic Processing Unit), the authors propose to implement the calculation of the silhouette on the GPU by using Geometry Shader. The authors present the step which made it possible to lead to a concrete implementation of this algorithm, the modifications which were made, as well as a comparative study of results, followed by a discussion of these results and choices of implementation.
基金funded by China Scholarship Council(2020091-10135).
文摘Real-time rendering applications leverage heterogeneous computing to optimize performance.However,software development across multiple devices presents challenges,including data layout inconsistencies,synchronization issues,resource management complexities,and architectural disparities.Additionally,the creation of such systems requires verbose and unsafe programming models.Recent developments in domain-specific and unified shading languages aim to mitigate these issues.Yet,current programming models primarily address data layout consistency,neglecting other persistent challenges.In this paper,we introduce RenderKernel,a programming model designed to simplify the development of real-time rendering systems.Recognizing the need for a high-level approach,RenderKernel addresses the specific challenges of real-time rendering,enabling development on heterogeneous systems as if they were homogeneous.This model allows for early detection and prevention of errors due to system heterogeneity at compile-time.Furthermore,RenderKernel enables the use of common programming patterns from homogeneous environments,freeing developers from the complexities of underlying heterogeneous systems.Developers can focus on coding unique application features,thereby enhancing productivity and reducing the cognitive load associated with real-time rendering system development.
基金supported by the National Natural Science Foundation of China(11174087,10774049)State Key Laboratory of Subtropical Building Science,South China University of Technology
文摘This paper reports the recent works and progress on a PC and C++ language-based virtual auditory environment(VAE) system platform.By tracing the temporary location and orientation of listener's head and dynamically simulating the acoustic propagation from sound source to two ears,the system is capable of recreating free-field virtual sources at various directions and distances as well as auditory perception in reflective environment via headphone presentation.Schemes for improving VAE performance,including PCA-based(principal components analysis) near-field virtual source synthesis,simulating six degrees of freedom of head movement,are proposed.Especially,the PCA-based scheme greatly reduces the computational cost of multiple virtual sources synthesis.Test demonstrates that the system exhibits improved performances as compared with some existing systems.It is able to simultaneously render up to 280 virtual sources using conventional scheme,and 4500 virtual sources using the PCA-based scheme.A set of psychoacoustic experiments also validate the performance of the system,and at the same time,provide some preliminary results on the research of binaural hearing.The functions of the VAE system is being extended and the system serves as a flexible and powerful platform for future binaural hearing researches and virtual reality applications.
基金financial support from the National Natural Science Foundation of China(Grant Nos.52209125 and 51839003).
文摘Deep engineering disasters,such as rockbursts and collapses,are more related to the shear slip of rock joints.A novel multifunctional device was developed to study the shear failure mechanism in rocks.Using this device,the complete shearedeformation process and long-term shear creep tests could be performed on rocks under constant normal stiffness(CNS)or constant normal loading(CNL)conditions in real-time at high temperature and true-triaxial stress.During the research and development process,five key technologies were successfully broken through:(1)the ability to perform true-triaxial compressioneshear loading tests on rock samples with high stiffness;(2)a shear box with ultra-low friction throughout the entire stress space of the rock sample during loading;(3)a control system capable of maintaining high stress for a long time and responding rapidly to the brittle fracture of a rock sample as well;(4)a refined ability to measure the volumetric deformation of rock samples subjected to true triaxial shearing;and(5)a heating system capable of maintaining uniform heating of the rock sample over a long time.By developing these technologies,loading under high true triaxial stress conditions was realized.The apparatus has a maximum normal stiffness of 1000 GPa/m and a maximum operating temperature of 300C.The differences in the surface temperature of the sample are constant to within5C.Five types of true triaxial shear tests were conducted on homogeneous sandstone to verify that the apparatus has good performance and reliability.The results show that temperature,lateral stress,normal stress and time influence the shear deformation,failure mode and strength of the sandstone.The novel apparatus can be reliably used to conduct true-triaxial shear tests on rocks subjected to high temperatures and stress.
基金supported by the National Natural Science Foundation of China(Nos.52121003,51827901 and 52204110)China Postdoctoral Science Foundation(No.2022M722346)+1 种基金the 111 Project(No.B14006)the Yueqi Outstanding Scholar Program of CUMTB(No.2017A03).
文摘Understanding the variations in microscopic pore-fracture structures(MPFS) during coal creep under pore pressure and stress coupling is crucial for coal mining and effective gas treatment. In this manuscript, a triaxial creep test on deep coal at various pore pressures using a test system that combines in-situ mechanical loading with real-time nuclear magnetic resonance(NMR) detection was conducted.Full-scale quantitative characterization, online real-time detection, and visualization of MPFS during coal creep influenced by pore pressure and stress coupling were performed using NMR and NMR imaging(NMRI) techniques. The results revealed that seepage pores and microfractures(SPM) undergo the most significant changes during coal creep, with creep failure gradually expanding from dense primary pore fractures. Pore pressure presence promotes MPFS development primarily by inhibiting SPM compression and encouraging adsorption pores(AP) to evolve into SPM. Coal enters the accelerated creep stage earlier at lower stress levels, resulting in more pronounced creep deformation. The connection between the micro and macro values was established, demonstrating that increased porosity at different pore pressures leads to a negative exponential decay of the viscosity coefficient. The Newton dashpot in the ideal viscoplastic body and the Burgers model was improved using NMR experimental results, and a creep model that considers pore pressure and stress coupling using variable-order fractional operators was developed. The model’s reasonableness was confirmed using creep experimental data. The damagestate adjustment factors ω and β were identified through a parameter sensitivity analysis to characterize the effect of pore pressure and stress coupling on the creep damage characteristics(size and degree of difficulty) of coal.
基金supported by the JST ACCEL(JPMJAC1602)JSPS KAKENHI(JP17H06101,18K18075,and JP19H01129).
文摘This paper proposes a lightweight bidirectional scattering distribution function(BSDF)model for layered materials with anisotropic reflection and refraction properties.In our method,each layer of the materials can be described by a microfacet BSDF using an anisotropic normal distribution function(NDF).Furthermore,the NDFs of layers can be defined on tangent vector fields,which differ from layer to layer.Our method is based on a previous study in which isotropic BSDFs are approximated by projecting them onto base planes.However,the adequateness of this previous work has not been well investigated for anisotropic BSDFs.In this paper,we demonstrate that the projection is also applicable to anisotropic BSDFs and that the BSDFs are approximated by elliptical distributions using covariance matrices.
基金funded and supported by the Comprehensive Research Facility for Fusion Technology Program of China(No.2018-000052-73-01-001228)the HFIPS Director’s Fund(No.YZJJKX202301)+1 种基金the Anhui Provincial Major Science and Technology Project(No.2023z020004)Task JB22001 from the Anhui Provincial Department of Economic and Information Technology。
文摘A real-time data processing system is designed for the carbon dioxide dispersion interferometer(CO_(2)-DI)on EAST.The system utilizes the parallel and pipelining capabilities of an fieldprogrammable gate array(FPGA)to digitize and process the intensity of signals from the detector.Finally,the real-time electron density signals are exported through a digital-to-analog converter(DAC)module in the form of analog signals.The system has been successfully applied in the CO_(2)-DI system to provide low-latency electron density input to the plasma control system on EAST.Experimental results of the latest campaign with long-pulse discharges on EAST(2022–2023)demonstrate that the system can respond effectively in the case of rapid density changes,proving its reliability and accuracy for future electron density calculation.
基金Supported by National Natural Science Foundation of China(Grant Nos.51875031,52242507)Beijing Municipal Natural Science Foundation of China(Grant No.3212010)Beijing Municipal Youth Backbone Personal Project of China(Grant No.2017000020124 G018).
文摘The co-frequency vibration fault is one of the common faults in the operation of rotating equipment,and realizing the real-time diagnosis of the co-frequency vibration fault is of great significance for monitoring the health state and carrying out vibration suppression of the equipment.In engineering scenarios,co-frequency vibration faults are highlighted by rotational frequency and are difficult to identify,and existing intelligent methods require more hardware conditions and are exclusively time-consuming.Therefore,Lightweight-convolutional neural networks(LW-CNN)algorithm is proposed in this paper to achieve real-time fault diagnosis.The critical parameters are discussed and verified by simulated and experimental signals for the sliding window data augmentation method.Based on LW-CNN and data augmentation,the real-time intelligent diagnosis of co-frequency is realized.Moreover,a real-time detection method of fault diagnosis algorithm is proposed for data acquisition to fault diagnosis.It is verified by experiments that the LW-CNN and sliding window methods are used with high accuracy and real-time performance.
基金supported by MOA project 111AS-7.3.4-SB-S3 and 112AS-7.3.4-SB-S3.
文摘At present,debris flow warning uses precipitation threshold and issues regional warning throughout the world.Precipitation threshold warning is less accurate and in most of the time large portion of unaffected population are evacuated.More precise warning should use direct monitoring.There are many debris flow monitoring stations but no real time warning system in use.The main reason is that the identification and confirmation of debris flow occurrence requires human interaction and it is too slow.A debris flow monitoring and warning system has been installed in the midstream section of Yusui Stream,Taiwan China.The monitoring station operates fully automatically,providing early warnings without the need for manual intervention.The system comprises two webcam cameras,two Micro-Electro-Mechanical Systems(MEMS),and a rain gauge.The arrival of debris flows is detected and confirmed through both webcam images and MEMS signals.Once debris flow is detected,the system automatically issues a warning to the affected areas via voice messages,line messages,broadcasts,and web-based alerts.The webcam cameras are also used to estimate debris flow velocity and flow height,while the MEMS sensors are utilized to determine the phase speed and flow rate.On July 24th,2014,Typhoon Gaemi triggered several debris flows,and the system successfully issued several warnings automatically.The entire video record,along with depth variation data,was recorded automatically.
基金supported by the National Research Foundation of Korea (NRF) grant funded by the Korean Government (MSIT) (No.2022M3J7A1062940,2021R1A5A6002853,and 2021R1A2C3011585)supported by the Technology Innovation Program (20015577)funded by the Ministry of Trade,Industry&Energy (MOTIE,Korea)。
文摘This review explores glucose monitoring and management strategies,emphasizing the need for reliable and userfriendly wearable sensors that are the next generation of sensors for continuous glucose detection.In addition,examines key strategies for designing glucose sensors that are multi-functional,reliable,and cost-effective in a variety of contexts.The unique features of effective diabetes management technology are highlighted,with a focus on using nano/biosensor devices that can quickly and accurately detect glucose levels in the blood,improving patient treatment and control of potential diabetes-related infections.The potential of next-generation wearable and touch-sensitive nano biomedical sensor engineering designs for providing full control in assessing implantable,continuous glucose monitoring is also explored.The challenges of standardizing drug or insulin delivery doses,low-cost,real-time detection of increased blood sugar levels in diabetics,and early digital health awareness controls for the adverse effects of injectable medication are identified as unmet needs.Also,the market for biosensors is expected to expand significantly due to the rising need for portable diagnostic equipment and an ever-increasing diabetic population.The paper concludes by emphasizing the need for further research and development of glucose biosensors to meet the stringent requirements for sensitivity and specificity imposed by clinical diagnostics while being cost-effective,stable,and durable.
基金supported by the National Natural Science Foundation of China(Grant No.51677058)。
文摘To address the impact of wind-power fluctuations on the stability of power systems,we propose a comprehensive approach that integrates multiple strategies and methods to enhance the efficiency and reliability of a system.First,we employ a strategy that restricts long-and short-term power output deviations to smoothen wind power fluctuations in real time.Second,we adopt the sliding window instantaneous complete ensemble empirical mode decomposition with adaptive noise(SW-ICEEMDAN)strategy to achieve real-time decomposition of the energy storage power,facilitating internal power distribution within the hybrid energy storage system.Finally,we introduce a rule-based multi-fuzzy control strategy for the secondary adjustment of the initial power allocation commands for different energy storage components.Through simulation validation,we demonstrate that the proposed comprehensive control strategy can smoothen wind power fluctuations in real time and decompose energy storage power.Compared with traditional empirical mode decomposition(EMD),ensemble empirical mode decomposition(EEMD),and complete ensemble empirical mode decomposition with adaptive noise(CEEMDAN)decomposition strategies,the configuration of the energy storage system under the SW-ICEEMDAN control strategy is more optimal.Additionally,the state-of-charge of energy storage components fluctuates within a reasonable range,enhancing the stability of the power system and ensuring the secure operation of the energy storage system.
基金funded by Anhui Provincial Natural Science Foundation(No.2208085ME128)the Anhui University-Level Special Project of Anhui University of Science and Technology(No.XCZX2021-01)+1 种基金the Research and the Development Fund of the Institute of Environmental Friendly Materials and Occupational Health,Anhui University of Science and Technology(No.ALW2022YF06)Anhui Province New Era Education Quality Project(Graduate Education)(No.2022xscx073).
文摘The real-time detection and instance segmentation of strawberries constitute fundamental components in the development of strawberry harvesting robots.Real-time identification of strawberries in an unstructured envi-ronment is a challenging task.Current instance segmentation algorithms for strawberries suffer from issues such as poor real-time performance and low accuracy.To this end,the present study proposes an Efficient YOLACT(E-YOLACT)algorithm for strawberry detection and segmentation based on the YOLACT framework.The key enhancements of the E-YOLACT encompass the development of a lightweight attention mechanism,pyramid squeeze shuffle attention(PSSA),for efficient feature extraction.Additionally,an attention-guided context-feature pyramid network(AC-FPN)is employed instead of FPN to optimize the architecture’s performance.Furthermore,a feature-enhanced model(FEM)is introduced to enhance the prediction head’s capabilities,while efficient fast non-maximum suppression(EF-NMS)is devised to improve non-maximum suppression.The experimental results demonstrate that the E-YOLACT achieves a Box-mAP and Mask-mAP of 77.9 and 76.6,respectively,on the custom dataset.Moreover,it exhibits an impressive category accuracy of 93.5%.Notably,the E-YOLACT also demonstrates a remarkable real-time detection capability with a speed of 34.8 FPS.The method proposed in this article presents an efficient approach for the vision system of a strawberry-picking robot.
基金the National Key Research and Development Program of China(Grant No.2021YFA1402102)the National Natural Science Foundation of China(Grant No.62171249)the Fund by Tsinghua University Initiative Scientific Research Program.
文摘The composite time scale(CTS)provides a stable,accurate,and reliable time scale for modern society.The improvement of CTS’s real-time performance will improve its stability,which strengths related applications’performance.Aiming at this goal,a method achieved by determining the optimal calculation interval and accelerating adjustment stage is proposed in this paper.The determinants of the CTS’s calculation interval(characteristics of the clock ensemble,the measurement noise,the time and frequency synchronization system’s noise and the auxiliary output generator noise floor)are studied and the optimal calculation interval is obtained.We also investigate the effect of ensemble algorithm’s initial parameters on the CTS’s adjustment stage.A strategy to get the reasonable initial parameters of ensemble algorithm is designed.The results show that the adjustment stage can be finished rapidly or even can be shorten to zero with reasonable initial parameters.On this basis,we experimentally generate a distributed CTS with a calculation interval of 500 s and its stability outperforms those of the member clocks when the averaging time is longer than1700 s.The experimental result proves that the CTS’s real-time performance is significantly improved.