The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments...The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.展开更多
In order to establish a stereoscopic image quality assessment method which is consistent with human visual perception,we propose an objective stereoscopic image quality assessment method.It takes into account the stro...In order to establish a stereoscopic image quality assessment method which is consistent with human visual perception,we propose an objective stereoscopic image quality assessment method.It takes into account the strong correlation and high degree of structural between pixels of image.This method contains two models.One is the quality synthetic assessment of left-right view images,which is based on human visual characteristics,we use the Singular Value Decomposition(SVD)that can represent the degree of the distortion,and combine the qualities of left and right images by the characteristics of binocular superposition.The other model is stereoscopic perception quality assessment,due to strong stability of image’s singular value characteristics,we calculate the distance of the singular values and structural characteristic similarity of the absolute difference maps,and utilize the statistical value of the global error to evaluate stereoscopic perception.Finally,we combine two models to describe the stereoscopic image quality.Experimental results show that the correlation coefficients of the proposed assessment method and the human subjective perception are above 0.93,and the mean square errors are all less than 6.2,under JPEG,JP2K compression,Gaussian blurring,Gaussian white noise,H.264 coding distortion,and hybrid cross distortion.It indicates that the proposed stereoscopic objective method is consistent with human visual properties and also of availability.展开更多
Higher-precision determinations of hydrate reservoirs, hydrate saturation levels and storage estimations are important for guaranteeing the ability to continuously research, develop and utilize natural gas hydrate res...Higher-precision determinations of hydrate reservoirs, hydrate saturation levels and storage estimations are important for guaranteeing the ability to continuously research, develop and utilize natural gas hydrate resources in China. With seismic stereoscopic detection technology, which fully combines the advantages of different seismic detection models, hydrate formation layers can be observed with multiangle, wide-azimuth, wide-band data with a high precision. This technique provides more reliable data for analyzing the distribution characteristics of gas hydrate reservoirs, establishing velocity models, and studying the hydrate-sensitive properties of petrophysical parameters;these data are of great significance for the exploration and development of natural gas hydrate resources. Based on a velocity model obtained from the analysis of horizontal streamer velocity data in the hydrate-bearing area of the Shenhu Sea, this paper uses three VCs(longitudinal spacing of 25 m) and four OBSs(transverse spacing of 200 m) to jointly detect seismic datasets consisting of wave points based on an inversion of traveltime imaging sections. Accordingly, by comparing the differences between the seismic phases in the original data and the forward-modeled seismic phases, multiangle coverage constraint corrections are applied to the initial velocity model, and the initial model is further optimized, thereby improving the imaging quality of the streamer data. Petrophysical elastic parameters are the physical parameters that are most directly and closely related to rock formations and reservoir physical properties. Based on the optimized velocity model, the rock elastic hydrate-sensitive parameters of the hydrate reservoirs in the study area are inverted, and the sensitivities of the petrophysical parameters to natural gas hydrates are investigated. According to an analysis of the inversion results obtained from these sensitive parameters, λρ, Vp and λμ are simultaneously controlled by the bulk modulus and shear modulus, while Vs and μρ are controlled only by the shear modulus, and the latter two parameters are less sensitive to hydrate-bearing layers. The bulk modulus is speculated to be more sensitive than the shear modulus to hydrates. In other words, estimating the specific gravity of the shear modulus among the combined parameters can affect the results from the combined elastic parameters regarding hydrate reservoirs.展开更多
With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention a...With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention and control in China.The stereoscopic monitoring of regional PM_(2.5) and O_(3) and their precursors is crucial to achieve coordinated control.However,current monitoring networks are currently inadequate for monitoring the vertical profiles of both PM_(2.5) and O_(3) simultaneously and support air quality control.The University of Science and Technology of China(USTC)has established a nationwide ground-based hyperspectral stereoscopic remote sensing network based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)since 2015.This monitoring network provides a significant opportunity for the regional coordinated control of PM_(2.5) and O_(3) in China.One-year vertical profiles of aerosol,NO_(2) and HCHO monitored from four MAX-DOAS stations installed in four megacities(Beijing,Shanghai,Shenzhen,and Chongqing)were used to characterize their vertical distribution differences in four key regions,Jing–Jin–Ji(JJJ),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Sichuan Basin(SB),respectively.The normalized and yearly averaged aerosol vertical profiles below 400 m in JJJ and PRD exhibit a box shape and a Gaussian shape,respectively,and both show exponential shapes in YRD and SB.The NO_(2) vertical profiles in four regions all exhibit exponential shapes because of vehicle emissions.The shape of the HCHO vertical profile in JJJ and PRD was Gaussian,whereas an exponential shape was shown in YRD and SB.Moreover,a regional transport event occurred at an altitude of 600–1000 m was monitored in the southwest–northeast pathway of the North China Plain(NCP)by five MAX-DOAS stations(Shijiazhuang(SJZ),Wangdu(WD),Nancheng(NC),Chinese Academy of Meteorological Sciences(CAMS),and University of Chinese Academy of Sciences(UCAS))belonging to the above network.The aerosol optical depths(AOD)in these five stations decreased in the order of SJZ>WD>NC>CAMS>UCAS.The short-distance regional transport of NO2 in the 700–900 m layer was monitored between WD and NC.As an important precursor of secondary aerosol,the peak of NO_(2) air mass in WD and NC all occurred 1 h earlier than that of aerosol.This was also observed for the short-distance regional transport of HCHO in the 700–900 m layer between NC and CAMS,which potentially affected the O_(3) concentration in Beijing.Finally,CAMS was selected as a typical site to determine the O_(3)–NO_(x)–volatile organic compounds(VOCs)sensitivities in vertical space.We found the production of O_(3) changed from predominantly VOCs-limited conditions to mainly mixed VOCs–NO_(x)-limited condition from the 0–100 m layer to the 200–300 m layer.In addition,the downward transport of O_(3) could contribute to the increase of ground surface O_(3) concentration.This ground-based hyperspectral stereoscopic remote sensing network provide a promising strategy to support management of PM_(2.5) and O_(3) and their precursors and conduct attribution of sources.展开更多
An autostereoscopic display composed of a directional backlight, an image display panel, a striped half-wave plate,and a polarized lenticular lens array is proposed. The directional backlight emitting the parallel lig...An autostereoscopic display composed of a directional backlight, an image display panel, a striped half-wave plate,and a polarized lenticular lens array is proposed. The directional backlight emitting the parallel light can redirect the cones of light to lenticular lens array and reduce the chromatic spatial-interference effect. The striped half-wave plate, located in front of the image display panel, transformed the polarization direction of the lights from the directional backlight into two mutually perpendicular directions. The polarized lenticular lens array not only can divide the light from the left and right view images to send to left and right eyes but also can reduce the crosstalk of the stereoscopic images. The proposed autostereoscopic display can produce high quality stereoscopic images without crosstalk at the optimal viewing distance.展开更多
Stereoscopic three-dimensional echocardiography(S-3DE) is a novel displaying technol-ogy based on real-time 3-dimensional echocardiography (RT-3DE). Our study was to evaluate the feasibility and efficiency of S-3D...Stereoscopic three-dimensional echocardiography(S-3DE) is a novel displaying technol-ogy based on real-time 3-dimensional echocardiography (RT-3DE). Our study was to evaluate the feasibility and efficiency of S-3DE in the diagnosis of atrial septal defect (ASD) and its use in the guidance for transcatheter ASD occlusion. Twelve patients with secundum ASD underwent RT-3DE examination and 9 of the 12 were subjected to transcatheter closure of ASD. Stereoscopic vision was generated with a high-performance volume renderer with red-green stereoscopic glasses. S-3DE was compared with standard RT-3D display for the assessment of the shape, size, and the surrounding tis-sues of ASD and for the guidance of ASD occlusion. The appearance rate of coronary sinus and the mean formation time of the IVC, SVC were compared. Our results showed that S-3DE could measure the diameter of ASD accurately and there was no significant difference in the measurements between S-3DE and standard 3D display (2.89±0.73 cm vs 2.85±0.72 cm, P〉0.05; r=0.96, P〈0.05). The appearance of coronary sinus for S-3DE was higher as compared with the standard 3D display (93.3% vs 100%). The mean time of the IVC, SVC for S-3DE monitor was slightly shorter than that of the standard 3D display (11.0±3.8 s vs 10.3±3.6 s, P〉0.05). The mean completion time of interven-tional procedure was shortened with S-3DE display as compared with standard 3D display (17.3±3.1 min vs 23.0±3.9 min, P〈0.05). Stereoscopic three-dimensional echocardiography could improve the visualization of three-dimensional echocardiography, facilitate the identification of the adjacent structures, decrease the time required for interventional manipulation. It may be a feasible, safe, and efficient tool for guiding transcatheter septal occlusion or the surgical interventions.展开更多
3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research...3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research.The history,fundamental principle,and devices of 3D stereoscopic visualization technology are reviewed in this paper.The authors’research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented.This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidification processes such as temperature,fluid flow,displacement,stress strain and microstructure,as well as the predicted defects such as shrinkage/porosity,cracks,and deformation.It can also be used for other areas relating to 3D models,such as assembling of dies,cores,etc.Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images.The spatial shape is observed better by the new method.The prospect of3D stereoscopic visualization in the casting aspect is discussed as well.The need for aided-viewing devices is still the most prominent problem of 3D stereoscopic visualization technology.However,3D stereoscopic visualization represents the tendency of visualization technology in the future;and as the problem is solved in the years ahead,great breakthroughs will certainly be made for its application in casting design and modeling and simulation of the casting processes.展开更多
With the development of stereoscopic technology, more attention is attracted on the stereoscopic three-dimensional(S3 D) content and service, and researches on images and videos have emerged in large numbers. This pap...With the development of stereoscopic technology, more attention is attracted on the stereoscopic three-dimensional(S3 D) content and service, and researches on images and videos have emerged in large numbers. This paper focuses mainly on visual comfort affected by characteristics of disparity for multiple objects. To find the relationship between disparity distribution and visual comfort perception, several subject evaluation experiments are done. The study contains two spatial distribution types of disparity: 1) only one of the foreground objects has zero disparity; 2) one of the foreground objects has positive disparity, while the other one has negative disparity. The experimental results and relative regression analysis provide appropriate relationship between disparity distribution and visual comfort for both conditions, which is significant to meet the applicant field in S3 D content acquisition, display adjustment and quality evaluation.展开更多
Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stere...Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video.展开更多
Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a c...Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a common axis. Due to the existence of the rotating mode, the desired relative position between every two agents is time-varying, and a Lyapunov-based approach is employed to solve the rotating formation control problem. Finally, simulation results are provided to illustrate the effectiveness of the theoretical results.展开更多
By using psychological and physiological indicators, the effects on the body of three-dimensional (3D) movies containing improper settings were evaluated with 139 university students. The experiment consisted of two s...By using psychological and physiological indicators, the effects on the body of three-dimensional (3D) movies containing improper settings were evaluated with 139 university students. The experiment consisted of two sessions: 1) a 3D movie containing improper 3D settings was compared with a 2D movie containing only the rightside images presented to both eyes, and 2) the original 3D movie was compared with the same 3D movie altered to contain improper 3D settings. The results of this experiment demonstrated clear deterioration of the subjective psychological indicators (degree of motion sickness after watching the movies and comfort level at 1-min intervals during the movie) with respect to the 3D movie containing improper settings. On the other hand, the physiological indicators (LF/HF ratio indicating the status of the autonomic nervous system) changed as a result of watching a 3D movie, but were unaffected by the presence or absence of improper 3D settings.展开更多
Strawberry is rich in nutrition,which is the only fresh fruit in winter in southern Xinjiang,with good prospect of stereoscopic cultivation.In this paper,the key techniques such as stereoscopic cultivation pattern,the...Strawberry is rich in nutrition,which is the only fresh fruit in winter in southern Xinjiang,with good prospect of stereoscopic cultivation.In this paper,the key techniques such as stereoscopic cultivation pattern,the combination of different modes,the substrate of strawberry cultivation,the drip irrigation system,the formula of nutrient solution,the selection of varieties,the propagation of seed and seedling,the induction of flower buds,the planting and management of plants,and the green control of diseases and insect pests are introduced,and greenhouse space and solar energy are fully used to maximize the economic and social benefits of strawberry farming combined with tourism.The results will further promote the quality and efficiency of strawberry industry in southern Xinjiang,and provide a reference for strawberry growers.展开更多
Objective:To study the effect of Stereoscopic Comprehensive of Therapy Zhuang Medicine on IL-6 in serum of patients with rheumatoid arthritis.Methods:Sixty rheumatoid arthritis patients who met the inclusion criteria ...Objective:To study the effect of Stereoscopic Comprehensive of Therapy Zhuang Medicine on IL-6 in serum of patients with rheumatoid arthritis.Methods:Sixty rheumatoid arthritis patients who met the inclusion criteria were selected and randomly divided into a control group and a treatment group using a random number table.Among them,30 cases in the control group were treated with Western medicine,and 30 cases in the treatment group were treated with Western medical and Stereoscopic Comprehensive Therapy of Zhuang Medicine.The observation period was 8 weeks.Results:After 8 weeks of treatment,the level of IL-6 in the treatment group and the control group decreased,and the treatment group was better than the control group(P<0.05).Conclusion:The Stereoscopic Comprehensive of Zhuang Medicine can reduce the level of IL-6 in the serum of patients with rheumatoid arthritis,and has a good regulating effect on the inflammation of rheumatoid arthritis.展开更多
This article explores the impact of the three-dimensional cultivation mode on the development of the Suzhou tea industry,focusing on the diversified estimation of the value of output per acre and sales mode.It introdu...This article explores the impact of the three-dimensional cultivation mode on the development of the Suzhou tea industry,focusing on the diversified estimation of the value of output per acre and sales mode.It introduces the history and traditional cultivation practices of tea in Suzhou,as well as the current challenges and problems faced by the industry.An in-depth analysis was conducted on the overview and improvement plans of the three-dimensional cultivation mode,covering relevant technical methods.Based on this analysis,the impact of the three-dimensional cultivation on the value of output per acre was studied and predicted.Its potential and advantages were explored and compared with the effectiveness of traditional cultivation models.Additionally,the impact of the three-dimensional cultivation mode on sales was analyzed,examining its market adaptability and competitiveness,as well as its advantages in expanding sales channels and market coverage.The study also focused on the promoting effect of diversified sales models on the Suzhou tea industry,including direct consumption market development,tea processing product development and promotion,and the integration of tea culture and the tourism industry.To ensure sustainable development,the article evaluates the environmental impact,economic feasibility,social benefits,and farmer benefits of the three-dimensional cultivation model.Finally,the prospects for the development of the Suzhou tea industry were discussed,and the positioning and response strategies of the threedimensional cultivation model were proposed.展开更多
This paper presents experimental measurements of the flow field in a Low-speed Turbine Cascade using a stereoscopic particle-image velocimetry(SPIV). During the measurements, a pair of frame-straddling-based CCD camer...This paper presents experimental measurements of the flow field in a Low-speed Turbine Cascade using a stereoscopic particle-image velocimetry(SPIV). During the measurements, a pair of frame-straddling-based CCD cameras were configured at different sides of the laser light sheet, and appropriate tracing particles(DEHS) were employed. The measurements were conducted at the incidence angle of 0 degree and exit Reynolds number of 1.7 × 105 with the tip clearance 1.18% of blade chord. The tip flow features, such as the evolution and breakdown of tip leakage vortex, the horseshoe vortex, turbulence characteristics of tip leakage flow, were studied for the flow field analysis. The results showed that the tip leakage flow/vortex mainly dominate flow fields in the tip region. The tip leakage vortex performs as a concentrated vortex before its breaking down and splitting into small vortices. The highest turbulence intensity mainly occurs in the tip region along with the trajectory of tip leakage vortex, and when the vortex breaks down, the turbulence intensity reduces rapidly. Additionally, the SPIV with this configuration also shows an advantage in investigating the flow structures and mechanism inside the turbine cascade.展开更多
Spectral analysis shows a low-frequency shadow under the BSR interface. Traditional low-frequency shadow analysis is based on stacked data. In order to understand the BSR low-frequency shadow more clearly, a frequency...Spectral analysis shows a low-frequency shadow under the BSR interface. Traditional low-frequency shadow analysis is based on stacked data. In order to understand the BSR low-frequency shadow more clearly, a frequency division analysis on stereoscopic observation seismic data based on the adaptive optimal-kernel (AOK) frequency analysis method is presented. It includes ocean-bottom seismometer (OBS) data (common receiver point data including vertical and horizontal components), vertical cable data (common receiver point data) and horizontal cable data (stacked section of different offsets). The OBS data frequency analysis gets a conclusion that vertical component has a significant effect on the low-frequency shadow, but the horizontal component did not. The vertical cable data shows that the low frequency band of vertical cable is wider than OBS. And then the horizontal cable data frequency analysis points out that the bigger the angle of incidence is, the more obvious the low-frequency shadow will be. The low-frequency shadow feature is shown in the stereoscopic observation field and the visual effect on com- mon reception point data is better. The lateral reservoir distribution characteristics are predicted from low-frequency shadow feature analysis of the hydrate BSR based on stereoscopic observation.展开更多
We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we mode...We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we model distortion energies to prevent important video contents from deforming. Then, to maintain depth mapping stability, we model disparity variation energies to constraint the disparity range both in spatial and temporal domains. The last component of our method is a non-uniform, pixel-wise warp to the target resolution based on these energy models. Using this method, we can process the original stereoscopic video to generate new, high-perceptual-quality versions at different display resolutions. For evaluation, we conduct a user study; we also discuss the performance of our method.展开更多
We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investi...We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investigated with theoretical calculations and experiments by use of several kinds of LED panels, such as a fine-pitch LED panel and a 140-inch large LED panel. Limitations of viewing angle by parallax barrier are analyzed in conventional black stripes on a transparent substrate type and in aperture grille type. Experimental results straw use of aperture grille increases contrast and reduce reflection on the aperture surface.展开更多
Pixel disparity—the offset of corresponding pixels between left and right views—is a crucial parameter in stereoscopic three-dimensional(S3D)video, as it determines the depth perceived by the human visual system(HVS...Pixel disparity—the offset of corresponding pixels between left and right views—is a crucial parameter in stereoscopic three-dimensional(S3D)video, as it determines the depth perceived by the human visual system(HVS). Unsuitable pixel disparity distribution throughout an S3 D video may lead to visual discomfort. We present a unified and extensible stereoscopic video disparity adjustment framework which improves the viewing experience for an S3 D video by keeping the perceived 3D appearance as unchanged as possible while minimizing discomfort. We first analyse disparity and motion attributes of S3 D video in general, then derive a wide-ranging visual discomfort metric from existing perceptual comfort models. An objective function based on this metric is used as the basis of a hierarchical optimisation method to find a disparity mapping function for each input video frame. Warping-based disparity manipulation is then applied to the input video to generate the output video, using the desired disparity mappings as constraints. Our comfort metric takes into account disparity range, motion, and stereoscopic window violation; the framework could easily be extended to use further visual comfort models. We demonstrate the power of our approach using both animated cartoons and real S3 D videos.展开更多
Stereoscopic microscopy is a promising technology to obtain three-dimensional microscopic images.Such microscopes are based on the parallax effect,and as such require two lenses to focus at two different points.Geomet...Stereoscopic microscopy is a promising technology to obtain three-dimensional microscopic images.Such microscopes are based on the parallax effect,and as such require two lenses to focus at two different points.Geometrical constraints,however,restrict their numerical apertures to about 0.2,thus limiting the system’s resolution.Higher numerical apertures(.35)can be achieved with designs using only one bulk lens,but such systems are0 times more costly than the conventional ones.Thus,there is a pressing need for alternative solutions to improve the resolution of stereoscopic systems.Here,we show that high-resolution and low-cost stereoscopic systems can be obtained using birefringent single-layer metalenses.We design and fabricate a birefringent metalens operating at 532 nm with a numerical aperture as high as 0.4.The metalens is then used to demonstrate high-resolution stereoscopic imaging of biological samples.The microscopic images are further displayed and perceived vividly in an autostereoscopic display.Our demonstration paves the way to a new strategy to achieve high-resolution and low-cost stereoscopic microscopes.展开更多
文摘The need for efficient and reproducible development processes for sensor and perception systems is growing with their increased use in modern vehicles. Such processes can be achieved by using virtual test environments and virtual sensor models. In the context of this, the present paper documents the development of a sensor model for depth estimation of virtual three-dimensional scenarios. For this purpose, the geometric and algorithmic principles of stereoscopic camera systems are recreated in a virtual form. The model is implemented as a subroutine in the Epic Games Unreal Engine, which is one of the most common Game Engines. Its architecture consists of several independent procedures that enable a local depth estimation, but also a reconstruction of a whole three-dimensional scenery. In addition, a separate programme for calibrating the model is presented. In addition to the basic principles, the architecture and the implementation, this work also documents the evaluation of the model created. It is shown that the model meets specifically defined requirements for real-time capability and the accuracy of the evaluation. Thus, it is suitable for the virtual testing of common algorithms and highly automated driving functions.
基金Supported by the National Natural Science Foundation of China(Nos.6117116361271270+2 种基金6127102161111140392)National Science and Technology Support Program(2012BAH67F01)
文摘In order to establish a stereoscopic image quality assessment method which is consistent with human visual perception,we propose an objective stereoscopic image quality assessment method.It takes into account the strong correlation and high degree of structural between pixels of image.This method contains two models.One is the quality synthetic assessment of left-right view images,which is based on human visual characteristics,we use the Singular Value Decomposition(SVD)that can represent the degree of the distortion,and combine the qualities of left and right images by the characteristics of binocular superposition.The other model is stereoscopic perception quality assessment,due to strong stability of image’s singular value characteristics,we calculate the distance of the singular values and structural characteristic similarity of the absolute difference maps,and utilize the statistical value of the global error to evaluate stereoscopic perception.Finally,we combine two models to describe the stereoscopic image quality.Experimental results show that the correlation coefficients of the proposed assessment method and the human subjective perception are above 0.93,and the mean square errors are all less than 6.2,under JPEG,JP2K compression,Gaussian blurring,Gaussian white noise,H.264 coding distortion,and hybrid cross distortion.It indicates that the proposed stereoscopic objective method is consistent with human visual properties and also of availability.
基金the Fund of Acoustics Science and Technology Laboratory(KY1050019005,KY1050019006,KY10500180084)National Natural Science Foundation of China(Nos.41304096,41876053)+3 种基金the Fundamental Research Funds for the Central Universities(HEUCFJ180503)the National Science and Technology Major Project of China(2016ZX05024-001-002)National key research and development plan(2017YFC0307401)Fundamental Research Funds for the Central Universities(201762019).
文摘Higher-precision determinations of hydrate reservoirs, hydrate saturation levels and storage estimations are important for guaranteeing the ability to continuously research, develop and utilize natural gas hydrate resources in China. With seismic stereoscopic detection technology, which fully combines the advantages of different seismic detection models, hydrate formation layers can be observed with multiangle, wide-azimuth, wide-band data with a high precision. This technique provides more reliable data for analyzing the distribution characteristics of gas hydrate reservoirs, establishing velocity models, and studying the hydrate-sensitive properties of petrophysical parameters;these data are of great significance for the exploration and development of natural gas hydrate resources. Based on a velocity model obtained from the analysis of horizontal streamer velocity data in the hydrate-bearing area of the Shenhu Sea, this paper uses three VCs(longitudinal spacing of 25 m) and four OBSs(transverse spacing of 200 m) to jointly detect seismic datasets consisting of wave points based on an inversion of traveltime imaging sections. Accordingly, by comparing the differences between the seismic phases in the original data and the forward-modeled seismic phases, multiangle coverage constraint corrections are applied to the initial velocity model, and the initial model is further optimized, thereby improving the imaging quality of the streamer data. Petrophysical elastic parameters are the physical parameters that are most directly and closely related to rock formations and reservoir physical properties. Based on the optimized velocity model, the rock elastic hydrate-sensitive parameters of the hydrate reservoirs in the study area are inverted, and the sensitivities of the petrophysical parameters to natural gas hydrates are investigated. According to an analysis of the inversion results obtained from these sensitive parameters, λρ, Vp and λμ are simultaneously controlled by the bulk modulus and shear modulus, while Vs and μρ are controlled only by the shear modulus, and the latter two parameters are less sensitive to hydrate-bearing layers. The bulk modulus is speculated to be more sensitive than the shear modulus to hydrates. In other words, estimating the specific gravity of the shear modulus among the combined parameters can affect the results from the combined elastic parameters regarding hydrate reservoirs.
基金This research is supported by grants from the National Key Research and Development Program of China(2018YFC0213104)Project supported by the Presidential Foundation of the Hefei Institutes of Physical Science,Chinese Academy Sciences,China-“Spark”(YZJJ2021QN06)+6 种基金National Natural Science Foundation of China(41722501,91544212,51778596,41575021,41977184,and 41875043)National Key Research and Development Program of China(2017YFC0210002,2016YFC0203302,and 2017YFC0212800)Anhui Science and Technology Major Project(18030801111)the Strategic Priority Research Program of the Chinese Academy of Sciences(XDA23020301)the National Key Project for Causes and Control of Heavy Air Pollution(DQGG0102 and DQGG0205)the National High-Resolution Earth Observation Project of China(05-Y30B01-9001-19/20-3)Civil Aerospace Technology Advance Research Project(Y7K00100KJ).From 0-100 and 200-300 m layers,the production of O_(3) changed from predominantly VOCs-limited condition to mainly mixed VOCs-NOx-limited condition.
文摘With the coming of the“14th Five-Year Plan,”the coordinated control of particulate matter with an aerodynamic diameter no greater than 2.5 lm(PM_(2.5))and O_(3) has become a major issue of air pollution prevention and control in China.The stereoscopic monitoring of regional PM_(2.5) and O_(3) and their precursors is crucial to achieve coordinated control.However,current monitoring networks are currently inadequate for monitoring the vertical profiles of both PM_(2.5) and O_(3) simultaneously and support air quality control.The University of Science and Technology of China(USTC)has established a nationwide ground-based hyperspectral stereoscopic remote sensing network based on multi-axis differential optical absorption spectroscopy(MAX-DOAS)since 2015.This monitoring network provides a significant opportunity for the regional coordinated control of PM_(2.5) and O_(3) in China.One-year vertical profiles of aerosol,NO_(2) and HCHO monitored from four MAX-DOAS stations installed in four megacities(Beijing,Shanghai,Shenzhen,and Chongqing)were used to characterize their vertical distribution differences in four key regions,Jing–Jin–Ji(JJJ),Yangtze River Delta(YRD),Pearl River Delta(PRD),and Sichuan Basin(SB),respectively.The normalized and yearly averaged aerosol vertical profiles below 400 m in JJJ and PRD exhibit a box shape and a Gaussian shape,respectively,and both show exponential shapes in YRD and SB.The NO_(2) vertical profiles in four regions all exhibit exponential shapes because of vehicle emissions.The shape of the HCHO vertical profile in JJJ and PRD was Gaussian,whereas an exponential shape was shown in YRD and SB.Moreover,a regional transport event occurred at an altitude of 600–1000 m was monitored in the southwest–northeast pathway of the North China Plain(NCP)by five MAX-DOAS stations(Shijiazhuang(SJZ),Wangdu(WD),Nancheng(NC),Chinese Academy of Meteorological Sciences(CAMS),and University of Chinese Academy of Sciences(UCAS))belonging to the above network.The aerosol optical depths(AOD)in these five stations decreased in the order of SJZ>WD>NC>CAMS>UCAS.The short-distance regional transport of NO2 in the 700–900 m layer was monitored between WD and NC.As an important precursor of secondary aerosol,the peak of NO_(2) air mass in WD and NC all occurred 1 h earlier than that of aerosol.This was also observed for the short-distance regional transport of HCHO in the 700–900 m layer between NC and CAMS,which potentially affected the O_(3) concentration in Beijing.Finally,CAMS was selected as a typical site to determine the O_(3)–NO_(x)–volatile organic compounds(VOCs)sensitivities in vertical space.We found the production of O_(3) changed from predominantly VOCs-limited conditions to mainly mixed VOCs–NO_(x)-limited condition from the 0–100 m layer to the 200–300 m layer.In addition,the downward transport of O_(3) could contribute to the increase of ground surface O_(3) concentration.This ground-based hyperspectral stereoscopic remote sensing network provide a promising strategy to support management of PM_(2.5) and O_(3) and their precursors and conduct attribution of sources.
基金Project supported by the National High Technology Research and Development Program of China(Grant No.2012AA03A301)the National Natural Science Foundation of China(Grant No.60932007)+1 种基金the Postdoctoral Science Programs Foundation of the Ministry of Education of China(Grant No.0110032110029)the Key Projects in the Tianjin Science & Technology Pillar Program,China(Grant No.11ZCKFGX02000)
文摘An autostereoscopic display composed of a directional backlight, an image display panel, a striped half-wave plate,and a polarized lenticular lens array is proposed. The directional backlight emitting the parallel light can redirect the cones of light to lenticular lens array and reduce the chromatic spatial-interference effect. The striped half-wave plate, located in front of the image display panel, transformed the polarization direction of the lights from the directional backlight into two mutually perpendicular directions. The polarized lenticular lens array not only can divide the light from the left and right view images to send to left and right eyes but also can reduce the crosstalk of the stereoscopic images. The proposed autostereoscopic display can produce high quality stereoscopic images without crosstalk at the optimal viewing distance.
文摘Stereoscopic three-dimensional echocardiography(S-3DE) is a novel displaying technol-ogy based on real-time 3-dimensional echocardiography (RT-3DE). Our study was to evaluate the feasibility and efficiency of S-3DE in the diagnosis of atrial septal defect (ASD) and its use in the guidance for transcatheter ASD occlusion. Twelve patients with secundum ASD underwent RT-3DE examination and 9 of the 12 were subjected to transcatheter closure of ASD. Stereoscopic vision was generated with a high-performance volume renderer with red-green stereoscopic glasses. S-3DE was compared with standard RT-3D display for the assessment of the shape, size, and the surrounding tis-sues of ASD and for the guidance of ASD occlusion. The appearance rate of coronary sinus and the mean formation time of the IVC, SVC were compared. Our results showed that S-3DE could measure the diameter of ASD accurately and there was no significant difference in the measurements between S-3DE and standard 3D display (2.89±0.73 cm vs 2.85±0.72 cm, P〉0.05; r=0.96, P〈0.05). The appearance of coronary sinus for S-3DE was higher as compared with the standard 3D display (93.3% vs 100%). The mean time of the IVC, SVC for S-3DE monitor was slightly shorter than that of the standard 3D display (11.0±3.8 s vs 10.3±3.6 s, P〉0.05). The mean completion time of interven-tional procedure was shortened with S-3DE display as compared with standard 3D display (17.3±3.1 min vs 23.0±3.9 min, P〈0.05). Stereoscopic three-dimensional echocardiography could improve the visualization of three-dimensional echocardiography, facilitate the identification of the adjacent structures, decrease the time required for interventional manipulation. It may be a feasible, safe, and efficient tool for guiding transcatheter septal occlusion or the surgical interventions.
文摘3D stereoscopic visualization technology is coming into more and more common use in the field of entertainment,and this technology is also beginning to cut a striking figure in casting industry and scientific research.The history,fundamental principle,and devices of 3D stereoscopic visualization technology are reviewed in this paper.The authors’research achievements on the 3D stereoscopic visualization technology in the modeling and simulation of the casting process are presented.This technology can be used for the observation of complex 3D solid models of castings and the simulated results of solidification processes such as temperature,fluid flow,displacement,stress strain and microstructure,as well as the predicted defects such as shrinkage/porosity,cracks,and deformation.It can also be used for other areas relating to 3D models,such as assembling of dies,cores,etc.Several cases are given to compare the illustration of simulated results by traditional images and red-blue 3D stereoscopic images.The spatial shape is observed better by the new method.The prospect of3D stereoscopic visualization in the casting aspect is discussed as well.The need for aided-viewing devices is still the most prominent problem of 3D stereoscopic visualization technology.However,3D stereoscopic visualization represents the tendency of visualization technology in the future;and as the problem is solved in the years ahead,great breakthroughs will certainly be made for its application in casting design and modeling and simulation of the casting processes.
基金Supported by the National Science and Technology Planning Project(No.2012BAH38F00)the Engineering Research Project of Communication University of China(No.3132016XN1622)
文摘With the development of stereoscopic technology, more attention is attracted on the stereoscopic three-dimensional(S3 D) content and service, and researches on images and videos have emerged in large numbers. This paper focuses mainly on visual comfort affected by characteristics of disparity for multiple objects. To find the relationship between disparity distribution and visual comfort perception, several subject evaluation experiments are done. The study contains two spatial distribution types of disparity: 1) only one of the foreground objects has zero disparity; 2) one of the foreground objects has positive disparity, while the other one has negative disparity. The experimental results and relative regression analysis provide appropriate relationship between disparity distribution and visual comfort for both conditions, which is significant to meet the applicant field in S3 D content acquisition, display adjustment and quality evaluation.
基金Supported by National Natural Science Foundation of China(No.60972054)National High Technology Research and Development Program of China("863"Program,No.2009AA011507)
文摘Asymmetric stereoscopic video coding can take advantage of binocular suppression in human vision by representing one of the two views in lower quality.This paper proposes a bit allocation strategy for asymmetric stereoscopic video coding.In order to improve the accuracy of bit allocation and rate control in the left view,a proportionalintegral-derivative controller is adopted.Meanwhile,to control the quality fluctuation between consecutive frames of the left view,a quality controller is adopted.Besides,a fuzzy controller is proposed to control the variation in quality between the left and right views by comparing the PSNR disparity of two views with a fixed threshold,which is used to quantize the binocular psycho-visual redundancy and adjust the quantization parameter (QP) of the right view correspondingly.The proposed algorithm has been implemented in H.264/AVC video codec,and the experimental results show its effectiveness in rate control while keeping a good quality for the left view,and fewer bits are allocated for the right view so that the overall bit rate is saved by 7.2% at most without the loss of subjective visual quality for stereoscopic video.
基金supported by the National Natural Science Fundation of China(61074031)
文摘Distributed stereoscopic rotating formation control of networks of second-order agents is investigated. A distributed control protocol is proposed to enable all agents to form a stereoscopic formation and surround a common axis. Due to the existence of the rotating mode, the desired relative position between every two agents is time-varying, and a Lyapunov-based approach is employed to solve the rotating formation control problem. Finally, simulation results are provided to illustrate the effectiveness of the theoretical results.
文摘By using psychological and physiological indicators, the effects on the body of three-dimensional (3D) movies containing improper settings were evaluated with 139 university students. The experiment consisted of two sessions: 1) a 3D movie containing improper 3D settings was compared with a 2D movie containing only the rightside images presented to both eyes, and 2) the original 3D movie was compared with the same 3D movie altered to contain improper 3D settings. The results of this experiment demonstrated clear deterioration of the subjective psychological indicators (degree of motion sickness after watching the movies and comfort level at 1-min intervals during the movie) with respect to the 3D movie containing improper settings. On the other hand, the physiological indicators (LF/HF ratio indicating the status of the autonomic nervous system) changed as a result of watching a 3D movie, but were unaffected by the presence or absence of improper 3D settings.
基金Supported by Science and Technology Project of the First Division of Xinjiang Production and Construction Corps"Construction and Technology Demonstration of Strawberry Stereoscopic Cultivation Expo Park"(2019NY01)"Three Zones"Science and Technology Talents Project of Xinjiang Production and Construction Corps。
文摘Strawberry is rich in nutrition,which is the only fresh fruit in winter in southern Xinjiang,with good prospect of stereoscopic cultivation.In this paper,the key techniques such as stereoscopic cultivation pattern,the combination of different modes,the substrate of strawberry cultivation,the drip irrigation system,the formula of nutrient solution,the selection of varieties,the propagation of seed and seedling,the induction of flower buds,the planting and management of plants,and the green control of diseases and insect pests are introduced,and greenhouse space and solar energy are fully used to maximize the economic and social benefits of strawberry farming combined with tourism.The results will further promote the quality and efficiency of strawberry industry in southern Xinjiang,and provide a reference for strawberry growers.
文摘Objective:To study the effect of Stereoscopic Comprehensive of Therapy Zhuang Medicine on IL-6 in serum of patients with rheumatoid arthritis.Methods:Sixty rheumatoid arthritis patients who met the inclusion criteria were selected and randomly divided into a control group and a treatment group using a random number table.Among them,30 cases in the control group were treated with Western medicine,and 30 cases in the treatment group were treated with Western medical and Stereoscopic Comprehensive Therapy of Zhuang Medicine.The observation period was 8 weeks.Results:After 8 weeks of treatment,the level of IL-6 in the treatment group and the control group decreased,and the treatment group was better than the control group(P<0.05).Conclusion:The Stereoscopic Comprehensive of Zhuang Medicine can reduce the level of IL-6 in the serum of patients with rheumatoid arthritis,and has a good regulating effect on the inflammation of rheumatoid arthritis.
基金Suzhou Agricultural Vocational and Technical College Young Teachers Research Ability Enhancement Program“Research and Screening of Bacteria for Fermented Beverages of Vice Tea and Loquat Flower”(Project No.QN[2022]01)。
文摘This article explores the impact of the three-dimensional cultivation mode on the development of the Suzhou tea industry,focusing on the diversified estimation of the value of output per acre and sales mode.It introduces the history and traditional cultivation practices of tea in Suzhou,as well as the current challenges and problems faced by the industry.An in-depth analysis was conducted on the overview and improvement plans of the three-dimensional cultivation mode,covering relevant technical methods.Based on this analysis,the impact of the three-dimensional cultivation on the value of output per acre was studied and predicted.Its potential and advantages were explored and compared with the effectiveness of traditional cultivation models.Additionally,the impact of the three-dimensional cultivation mode on sales was analyzed,examining its market adaptability and competitiveness,as well as its advantages in expanding sales channels and market coverage.The study also focused on the promoting effect of diversified sales models on the Suzhou tea industry,including direct consumption market development,tea processing product development and promotion,and the integration of tea culture and the tourism industry.To ensure sustainable development,the article evaluates the environmental impact,economic feasibility,social benefits,and farmer benefits of the three-dimensional cultivation model.Finally,the prospects for the development of the Suzhou tea industry were discussed,and the positioning and response strategies of the threedimensional cultivation model were proposed.
基金supported by Science and Technology Foundation of State Key Laboratory(Grant No.9140C410205130C41153)funded by the National Natural Science Foundation of China,Grant No.51161130525 and 51136003supported by the 111 Project,No.B07009
文摘This paper presents experimental measurements of the flow field in a Low-speed Turbine Cascade using a stereoscopic particle-image velocimetry(SPIV). During the measurements, a pair of frame-straddling-based CCD cameras were configured at different sides of the laser light sheet, and appropriate tracing particles(DEHS) were employed. The measurements were conducted at the incidence angle of 0 degree and exit Reynolds number of 1.7 × 105 with the tip clearance 1.18% of blade chord. The tip flow features, such as the evolution and breakdown of tip leakage vortex, the horseshoe vortex, turbulence characteristics of tip leakage flow, were studied for the flow field analysis. The results showed that the tip leakage flow/vortex mainly dominate flow fields in the tip region. The tip leakage vortex performs as a concentrated vortex before its breaking down and splitting into small vortices. The highest turbulence intensity mainly occurs in the tip region along with the trajectory of tip leakage vortex, and when the vortex breaks down, the turbulence intensity reduces rapidly. Additionally, the SPIV with this configuration also shows an advantage in investigating the flow structures and mechanism inside the turbine cascade.
基金supported by the National Natural Science Foundation of China (Nos. 41304096, 41176077)the National Science and Technology Major Project of China (No. 2016ZX05024-001-002)+1 种基金the National High-Tech R & D Program of China (863 Program) (No. 2013AA092501)the Fundamental Research Funds for the Central Universities (No. 201762019)
文摘Spectral analysis shows a low-frequency shadow under the BSR interface. Traditional low-frequency shadow analysis is based on stacked data. In order to understand the BSR low-frequency shadow more clearly, a frequency division analysis on stereoscopic observation seismic data based on the adaptive optimal-kernel (AOK) frequency analysis method is presented. It includes ocean-bottom seismometer (OBS) data (common receiver point data including vertical and horizontal components), vertical cable data (common receiver point data) and horizontal cable data (stacked section of different offsets). The OBS data frequency analysis gets a conclusion that vertical component has a significant effect on the low-frequency shadow, but the horizontal component did not. The vertical cable data shows that the low frequency band of vertical cable is wider than OBS. And then the horizontal cable data frequency analysis points out that the bigger the angle of incidence is, the more obvious the low-frequency shadow will be. The low-frequency shadow feature is shown in the stereoscopic observation field and the visual effect on com- mon reception point data is better. The lateral reservoir distribution characteristics are predicted from low-frequency shadow feature analysis of the hydrate BSR based on stereoscopic observation.
基金supported by the National Basic Research Program of China under Grant No. 2011CB302206the National Natural Science Foundation of China under Grant Nos. 61272226 and 61272231Beijing Key Laboratory of Networked Multimedia
文摘We propose a disparity-constrained retargeting method for stereoscopic 3D video, which simultaneously resizes a binocular video to a new aspect ratio and remaps the depth to the perceptual comfort zone. First, we model distortion energies to prevent important video contents from deforming. Then, to maintain depth mapping stability, we model disparity variation energies to constraint the disparity range both in spatial and temporal domains. The last component of our method is a non-uniform, pixel-wise warp to the target resolution based on these energy models. Using this method, we can process the original stereoscopic video to generate new, high-perceptual-quality versions at different display resolutions. For evaluation, we conduct a user study; we also discuss the performance of our method.
文摘We propose a large parallax barrier by use of aperture grille. Main advantages of using aperture grille include no reflection and no absorption in apertures, as well as wide viewing angle. These advantages are investigated with theoretical calculations and experiments by use of several kinds of LED panels, such as a fine-pitch LED panel and a 140-inch large LED panel. Limitations of viewing angle by parallax barrier are analyzed in conventional black stripes on a transparent substrate type and in aperture grille type. Experimental results straw use of aperture grille increases contrast and reduce reflection on the aperture surface.
基金supported by the National Hightech R&D Program of China (Project No. 2013AA013903)the National Natural Science Foundation of China (Project Nos. 61272226 and 61133008)Research Grant of Beijing Higher Institution Engineering Research Center
文摘Pixel disparity—the offset of corresponding pixels between left and right views—is a crucial parameter in stereoscopic three-dimensional(S3D)video, as it determines the depth perceived by the human visual system(HVS). Unsuitable pixel disparity distribution throughout an S3 D video may lead to visual discomfort. We present a unified and extensible stereoscopic video disparity adjustment framework which improves the viewing experience for an S3 D video by keeping the perceived 3D appearance as unchanged as possible while minimizing discomfort. We first analyse disparity and motion attributes of S3 D video in general, then derive a wide-ranging visual discomfort metric from existing perceptual comfort models. An objective function based on this metric is used as the basis of a hierarchical optimisation method to find a disparity mapping function for each input video frame. Warping-based disparity manipulation is then applied to the input video to generate the output video, using the desired disparity mappings as constraints. Our comfort metric takes into account disparity range, motion, and stereoscopic window violation; the framework could easily be extended to use further visual comfort models. We demonstrate the power of our approach using both animated cartoons and real S3 D videos.
基金National Key Research and Development Program of China(2020YFC2007102)National Natural Science Foundation of China(11704421,11974436,12074444)+3 种基金Basic and Applied Basic Research Foundation of Guangdong Province(2020A1515011184,2020B1515020019)Innovation Group Project of Southern Marine Science and Engineering(Guangdong)Sao Paulo Research Foundation FAPESP(2020/00619-4,2021/06121-0)CNPq(307602/2021-4)。
文摘Stereoscopic microscopy is a promising technology to obtain three-dimensional microscopic images.Such microscopes are based on the parallax effect,and as such require two lenses to focus at two different points.Geometrical constraints,however,restrict their numerical apertures to about 0.2,thus limiting the system’s resolution.Higher numerical apertures(.35)can be achieved with designs using only one bulk lens,but such systems are0 times more costly than the conventional ones.Thus,there is a pressing need for alternative solutions to improve the resolution of stereoscopic systems.Here,we show that high-resolution and low-cost stereoscopic systems can be obtained using birefringent single-layer metalenses.We design and fabricate a birefringent metalens operating at 532 nm with a numerical aperture as high as 0.4.The metalens is then used to demonstrate high-resolution stereoscopic imaging of biological samples.The microscopic images are further displayed and perceived vividly in an autostereoscopic display.Our demonstration paves the way to a new strategy to achieve high-resolution and low-cost stereoscopic microscopes.