In the Grand Challenge of IEEE VAST Challenge 2017, we explore the systems in each mini-challenge, and combine the discoveries logically to provide a comprehensive story happened in the wildlife preserve. In this repo...
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We propose a novel Laplacian-based algorithm that simplifies triangle surface meshes and can provide different preservation ratios of geometric *** efficient and fast algorithm uses a 3D mesh model as input and initia...
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We propose a novel Laplacian-based algorithm that simplifies triangle surface meshes and can provide different preservation ratios of geometric *** efficient and fast algorithm uses a 3D mesh model as input and initially detects geometric features by using a Laplacian-based shape descriptor(L-descriptor).The algorithm further performs an optimized clustering approach that combines a Laplacian operator with K-means clustering algorithm to perform vertex ***,we introduce a Laplacian weighted cost function based on L-descriptor to perform feature weighting and error statistics comparison,which are further used to change the deletion order of the model elements and preserve the saliency *** algorithm can provide different preservation ratios of geometric features and may be extended to handle arbitrary mesh *** experiments on a variety of 3D surface meshes demonstrate the advantages of our algorithm in terms of improving accuracy and applicability,and preserving saliency geometric features.
Background This study proposes a series of geometry and physics modeling methods for personalized cardiovascular intervention procedures,which can be applied to a virtual endovascular *** Based on personalized clinica...
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Background This study proposes a series of geometry and physics modeling methods for personalized cardiovascular intervention procedures,which can be applied to a virtual endovascular *** Based on personalized clinical computed tomography angiography(CTA)data,mesh models of the cardiovascular system were constructed *** coupling 4 D magnetic resonance imaging(MRI)sequences corresponding to a complete cardiac cycle with related physics models,a hybrid kinetic model of the cardiovascular system was built to drive kinematics and dynamics *** that basis,the surgical procedures related to intervention instruments were simulated using specially-designed physics *** models can be solved in real-time;therefore,the complex interactions between blood vessels and instruments can be well ***,X-ray imaging simulation algorithms and realistic rendering algorithms for virtual intervention scenes are also *** particular,instrument tracking hardware with haptic feedback was developed to serve as the interaction interface of real instruments and the virtual intervention ***,a personalized cardiovascular intervention simulation system was developed by integrating the techniques mentioned *** This system supported instant modeling and simulation of personalized clinical data and significantly improved the visual and haptic immersions of vascular intervention *** It can be used in teaching basic cardiology and effectively satisfying the demands of intervention training,personalized intervention planning,and rehearsing.
Chess-board grid has been widely used for camera calibration and the associated feature point extraction algorithm draws much attention. In this paper, a multi-scale chess-board feature point detector is proposed, alo...
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This paper presents a method to automatically calculate texture maps for a given 3D object from a sequence of images. It is used in our image-based modeling approach after the registration of the images and the geomet...
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This paper presents a method to automatically calculate texture maps for a given 3D object from a sequence of images. It is used in our image-based modeling approach after the registration of the images and the geometric modeling has been done. We show that the presented method uses the information from all images by implicitly applying a weighting function. Using this approach, the consideration of modeled occlusions as well as the detection and removal of non-modeled occlusions is accomplished. The final resolution of the texture maps can be adjusted on a pixel/cm basis.
We present a novel adaptive color mapping method for virtual objects in mixed-reality environments. In several mixed-reality applications, added virtual objects should be visually indistinguishable from real objects. ...
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We present a novel adaptive color mapping method for virtual objects in mixed-reality environments. In several mixed-reality applications, added virtual objects should be visually indistinguishable from real objects. Recent mixed-reality methods use global-illumination algorithms to approach this goal. However, simulating the light distribution is not enough for visually plausible images. Since the observing camera has its very own transfer function from real-world radiance values to RGB colors, virtual objects look artificial just because their rendered colors do not match with those of the camera. Our approach combines an on-line camera characterization method with a heuristic to map colors of virtual objects to colors as they would be seen by the observing camera. Previous tone-mapping functions were not designed for use in mixed-reality systems and thus did not take the camera-specific behavior into account. In contrast, our method takes the camera into account and thus can also handle changes of its parameters during runtime. The results show that virtual objects look visually more plausible than by just applying tone-mapping operators.
The psychological health risk is one of the most serious and difficult risks to mitigate during manned deep space exploration[1].In a space capsule or station,the environment is isolated,and communication with the out...
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The psychological health risk is one of the most serious and difficult risks to mitigate during manned deep space exploration[1].In a space capsule or station,the environment is isolated,and communication with the outside is limited to telephone or delayed *** monotonous working schedule also aggravates loneliness and homesickness,which could trigger negative moods,such as depression and ***,an astronaut’s unstable emotional state could be a threat to the safety and performance of a space mission.
Compared to factors such as surface roughness, residual stress, particularly the compressive residual stress (CRS) amplitude and depth of CRS (D-CRS), is key factors influencing fatigue life. However, traditional mech...
Compared to factors such as surface roughness, residual stress, particularly the compressive residual stress (CRS) amplitude and depth of CRS (D-CRS), is key factors influencing fatigue life. However, traditional mechanical shot peening (MSP) has limitations in enhancing the CRS effect. In this study, a novnel thermal vibration MSP (TVMSP) integrated equipment is developed to address this challenge. The equipment combines temperature, vibration, MSP, and electric control systems, enabling the regulation of residual stress through multi-energy coupling. The vibration frequency and dynamic stress response of the equipment are analyzed using both simulations and experiments. The results demonstrated that with the optimized excitation parameters, the validation TVMSP treatment increases the D-CRS by 27.27 % and the maximum CRS (MCRS) amplitude by 16.02 %, compared to traditional MSP. The TVMSP treated surface exhibits dimples and increases surface roughness caused by thermal softening rather than vibration deformation. The developed TVMSP equipment offers a new approach for residual stress regulation and provides a technical and equipment reference for enhancing the fatigue life of key aerospace components.
Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military ***,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstructi...
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Holographic 3D display is highly desirable for numerous applications ranging from medical treatments to military ***,it is challenging to simultaneously achieve large viewing angle and high-fidelity color reconstruction due to the intractable constraints of existing ***,we conceptually propose and experimentally demonstrate a simple and feasible pathway of using a well-designed color liquid crystal grating to overcome the inevitable chromatic aberration and enlarge the holographic viewing angle,thus enabling large-viewing-angle and color holographic 3D *** use of color liquid crystal grating allows performing secondary diffraction modulation on red,green and blue reproduced images simultaneously and extending the viewing angle in the holographic 3D display *** principle,a chromatic aberration-free hologram generation mechanism in combination with the color liquid crystal grating is proposed to pave the way for on such a superior holographic 3D *** proposed system shows a color viewing angle of~50.12°,which is about 7 times that of the traditional system with a single spatial light *** work presents a paradigm for achieving desirable holographic 3D display,and is expected to provide a new way for the wide application of holographic display.
Model-based reconstruction methods are applied to the detailed reconstruction of buildings from close-range images. The 3D points obtained through image matching are segmented into a coarse polyhedral model with a rob...
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Model-based reconstruction methods are applied to the detailed reconstruction of buildings from close-range images. The 3D points obtained through image matching are segmented into a coarse polyhedral model with a robust regression algorithm, then the geometry of this model is refined with predefined shape templates in order to automatically recover a CAD-like model of the building surface. Reprojection of the 3D shape templates is used to optimally fit their parameters to the image information. Throughout the paper the investigated methods are demonstrated on real datasets.
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