Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons

Open Access. Powered by Scholars. Published by Universities.®

Articles 1351 - 1380 of 3382

Full-Text Articles in Physical Sciences and Mathematics

Mono-Slam Based Method For Stitching Images Of Sequence From Uav, Yuelong Ma, Zhao Yong, Xuefeng Cao Aug 2020

Mono-Slam Based Method For Stitching Images Of Sequence From Uav, Yuelong Ma, Zhao Yong, Xuefeng Cao

Journal of System Simulation

Abstract: It is an effective method to generate orthoimage from image sequence obtained from UAV. Most of the SfM-based methods for generating orthoimage are expensive computation and need hours or more to process image sequence, but the orthoimages generated finally are not satisfactory most of the time. An algorithm to stitch image sequence obtained from UAV incrementally was designed based on monocular SLAM generating orthoimage for large-scale instantaneously. Through the flow of SLAM, the system could estimate the position and attitude of the camera and the trajectory of UAV, meanwhile, generate a map of 3D point cloud. With the …


Study On Irregular Projection Surface Depth Perception Geometric Correction, Baoxing Bai, Yang Fan, Han Cheng, Zhang Chao Aug 2020

Study On Irregular Projection Surface Depth Perception Geometric Correction, Baoxing Bai, Yang Fan, Han Cheng, Zhang Chao

Journal of System Simulation

Abstract: In order to improve the universality of the projector projection scene, a method of depth perception geometric correction on the irregular projection surface was proposed. With the theoretical analysis of the coupling, the weaken coupling solution was proposed. The depth of the irregular projection surface could be acquired by the encoded color structured light. After that, the feedback was used to solve the maximum visual projection area, the dynamic slicing algorithm for the irregular surfaces depth information was used to pull away the stratification planes, so a corresponding homography matrix for each stratification plane was calculated and the homography …


Evaluation Method For Interior Layout Based On Voronoi Diagram, Milan Liu, Jiang Hao, Tianlu Mao, Zhaoqi Wang Aug 2020

Evaluation Method For Interior Layout Based On Voronoi Diagram, Milan Liu, Jiang Hao, Tianlu Mao, Zhaoqi Wang

Journal of System Simulation

Abstract: Three-dimensional interior model can be used to guide the indoor objects layout in real life. It is hard to evaluate an interior layout by a precise data because of the polymorphism and fuzzy of the evaluation problem of interior layout itself. In order to evaluate an interior layout objectively from the user’s view, an evaluation method for interior layout was proposed based on Voronoi Diagram. This method combined the knowledge of interior design and robot path planning, and generated moving lines in the scene by Voronoi Diagram. It could evaluate the interior layout objectively from aspects of patency, smoothness …


Multi-View Feature Learning Based On User Contributed Tag, Tian Feng, Fuhua Shang, Zhuoxuan Liu, Xukun Shen Aug 2020

Multi-View Feature Learning Based On User Contributed Tag, Tian Feng, Fuhua Shang, Zhuoxuan Liu, Xukun Shen

Journal of System Simulation

Abstract: A multi-view feature learning method based on user contributed tag was proposed. Bag-of-words representation for content feature and textual feature was learned. A multi-view feature learning framework was proposed to explicitly model the relevance between multimedia object and tags by learning a linear mapping from textual representation to visual representation. The learned feature encoded the information conveyed by original feature, and inner products of leaned features were preserved with a high probability with visual features and textual features. The complexity of the method is linear with respect to the size of dataset. Furthermore, the method can be extended …


Spatial Cues Gradient In Time Domain Based Audio Attention Computational Model, Hang Bo, Wang Yi, Changqing Kang, Huang Jian Aug 2020

Spatial Cues Gradient In Time Domain Based Audio Attention Computational Model, Hang Bo, Wang Yi, Changqing Kang, Huang Jian

Journal of System Simulation

Abstract: In virtual reality audio, sound source whose directions change rapidly should have higher attention level. But present bottom-up audio attention computational models extract the underlying characteristics of single channel audio such as energy, pitch, zero crossing rate etc., which can not effectively express the audio attention caused by such signals. To solve this problem, based on the psychological principles that spatial information affects attention, a model was proposed to introduce the short-term spatial gradient cues to measure the attention caused by the single audio source space direction changing. Compared to the traditional audio attention computational model, the recall of …


360-Degree Virtual Fitting Based On Kinect, Xiaoli Zhang, Junfeng Yao, Huang Ping Aug 2020

360-Degree Virtual Fitting Based On Kinect, Xiaoli Zhang, Junfeng Yao, Huang Ping

Journal of System Simulation

Abstract: A lot of virtual fitting systems only study human-computer interaction and clothing simulation, but they can’t make clothes model to rotate 360 degree along with human. To solve this problem, an improved method of virtual fitting based on Kinect using motion prediction was proposed. With the help of Kinect, the skeleton feature points of user for real-time tracking were obtained. According to the obtained information of the joint point of the head and color image, face was detected and judging the front or back of the user. The motion trajectory of the left and right shoulders’ joint points based …


Visualization Of 2d Dynamic Vector Fields Based On Topology Analysis, Li Chao, Lingda Wu, Bin Zhao Aug 2020

Visualization Of 2d Dynamic Vector Fields Based On Topology Analysis, Li Chao, Lingda Wu, Bin Zhao

Journal of System Simulation

Abstract: Flow is one of the most fundamental phenomenon in natural world. Flow visualization can give an intuitive view of flow fields and contribute to the observation and analysis of flow. Real flow fields are all dynamic while traditional visualization approaches are not able to reflect the trends of flows or the diversity inside them. Based on the research of Lagrangian Coherent Structures in Computational Fluid Dynamics, the concept of flow field topology was redefined, two typical 2D dynamic vector fields were selected for topology analysis, and the results were used to optimize the visual effects of geometric visualization. Experiments …


Graphics-Driver-Awared Heterogeneous Hardware-Accelerated Rendering Model, Zhiwei Ai, Cao Yi, Xiao Li, Huawei Wang Aug 2020

Graphics-Driver-Awared Heterogeneous Hardware-Accelerated Rendering Model, Zhiwei Ai, Cao Yi, Xiao Li, Huawei Wang

Journal of System Simulation

Abstract: As 3D graphics acceleration hardware technologies become more sophisticated, heterogeneous hardware-accelerated rendering model is one of effective means to improve interactive performance of large-scale data visualization. A graphics-driver-awared heterogeneous hardware-accelerated rendering model was proposed, and adaptive matching graphics architecture and graphics driver library in complex environment-improved the interactive performance of graphics rendering. Key technologies include runtime virtual layer technology, redundant graphics driver pool, running IntelliSense methods and graphics driver library dynamic loading technology. In practical application of visual analysis of nuclear reactor average flux, interactive performance of heterogeneous hardware rendering model available about 14 times speedup, has a …


Quadratic Rational Trigonometric Spline Curves With Shape Controlling, Xinru Liu, Manman Wei, Shengjun Liu, Dangfu Yang Aug 2020

Quadratic Rational Trigonometric Spline Curves With Shape Controlling, Xinru Liu, Manman Wei, Shengjun Liu, Dangfu Yang

Journal of System Simulation

Abstract: A new quadratic rational trigonometric spline curve with a shape parameter was proposed. The value control and the inflection-point control of the interpolation scheme were discussed in theory. And the optimal methods for calculating the desired inflection-points was proposed, by using optimization theory. Numerical experiments show the interpolation spline and the optimization method can be used in modeling design.


High-Level Descriptive Simulation Model For Underwater Virtual Maintenance, Lianen Ji, Ruisheng Sun, Luan Qi Aug 2020

High-Level Descriptive Simulation Model For Underwater Virtual Maintenance, Lianen Ji, Ruisheng Sun, Luan Qi

Journal of System Simulation

Abstract: The virtual simulation of underwater maintenance for oil and gas production involves a variety of maintenance processes and training cases. However, the existing modeling techniques mainly focused on the description of low-level model, such as geometric and physical properties, but lacked of abstraction and description of high-level application for the dynamic maintenance process. So a High-level Descriptive Simulation Model for Underwater Virtual Maintenance (HDMUM) was proposed. Three parts of simulation model, i.e., simulation entity, operation scene and maintenance process, were abstracted and described from the high-level application. All of the HDMUM components and their relationship were designed to …


Slicing Algorithm For Heterogeneous Nurbs Volume Parameterization Model, Chen Long, Ruan Chen, Wenyu Han Aug 2020

Slicing Algorithm For Heterogeneous Nurbs Volume Parameterization Model, Chen Long, Ruan Chen, Wenyu Han

Journal of System Simulation

Abstract: Heterogeneous NURBS Volume Parametric Model is attached importance for its ability to express the Information of materials continuously. But there is scarce study on the slicing algorithm of heterogeneous NURBS volume parametric model for rapid prototyping yet. A slicing algorithm for heterogeneous NURBS volume parametric model was proposed. The materials were expressed by putting the material information on control points and display different color to represent different materials. The model was divided into patches by iso-line. Find out the patches which intersect with the given cutting plane, then get the sections of the meshes containing material information. The results …


Online Furniture Layout Method Based On Case-Based Reasoning And Distance Fields, Peihua Song, Jinyuan Jia Aug 2020

Online Furniture Layout Method Based On Case-Based Reasoning And Distance Fields, Peihua Song, Jinyuan Jia

Journal of System Simulation

Abstract: A furniture layout method based on case-based reasoning and distance fields was proposed to meet online real-time response requirements. Three partial layout modes were summarized. Coupling layout mode was solved using case-based reasoning combined and mathematical model; matrix layout mode and furniture spacing algorithm were proposed; enclosed layout mode was solved using a personification rules and energy distribution function based on distance fields. Scene layout was divided into several partial layout modes, which were solved and synthetized. Experimental results show that effect of the method is similar to the real design case, and the method is robust, and the …


Method For Crowd Trampling And Crushing Simulation Based On Psychological Model, Tingting Liu, Liu Zhen, Yanjie Chai, Cuijuan Liu, Jiaxin Chen Aug 2020

Method For Crowd Trampling And Crushing Simulation Based On Psychological Model, Tingting Liu, Liu Zhen, Yanjie Chai, Cuijuan Liu, Jiaxin Chen

Journal of System Simulation

Abstract: With the accelerated development of urbanization, the number and the scale of cultural events have increased rapidly. In such crowded places, the risk of crowd trampling and crushing will be greatly increased. However, the current studies on crowd trampling and crushing simulation are relatively rare. In order to deduce the crowd trampling and crushing scene, a crowd trampling and crushing simulation model based on the psychological principles was proposed. The model considered emotional factors for the trampling and crushing in the dense crowd; simulated crowd trampling and crushing process and introduced the judgment criterions for the crowd trampling and …


Random Reversible Matrix Based Point Cloud Encryption, Zhaoxing Wu, Jin Xin, Chenggen Song, Chunwei Zhang, Xiaodong Li Aug 2020

Random Reversible Matrix Based Point Cloud Encryption, Zhaoxing Wu, Jin Xin, Chenggen Song, Chunwei Zhang, Xiaodong Li

Journal of System Simulation

Abstract: Paying less attention to the privacy protection in the 3D model, an encryption scheme based on chaotic map of 3D point cloud model was proposed, which realized the encryption of 3D point cloud, that used chaotic maps to generate a 3×3 random reversible matrix and a 3×1 translation vector, used the above random reversible matrix and the translation vector can transform each point of the point cloud to a homogeneous coordinate. After a lot of tests on different 3D point cloud models were carried out, the test results show that each point cloud model can be correctly encrypted …


Block Algorithm For Geometric Division Of Planar Region Based On Vector And Raster Interblended, Guojun Chen, Jingyi Liu, Yingying Huang Aug 2020

Block Algorithm For Geometric Division Of Planar Region Based On Vector And Raster Interblended, Guojun Chen, Jingyi Liu, Yingying Huang

Journal of System Simulation

Abstract: Using the vector method to maintain the accuracy of the data and the raster method to decrease the search scope, an algorithm was proposed for geometrics division of planar region based on vector and raster interblended. Special treatments for the raster filling polygon of "dead-zone" and the continuous multi-island polygon to adaptively dealt with the common polygon and the polygon with island, as well as the local individual polygons constructing and the global geometric division of planar region. In order to improve the time efficiency, geometric division of planar region used the block division process. Geometric division for sub-block …


Real Time Fluid Simulation Framework Based On Directcompute, Liu Lu, Liu Zhen, Gaoqi He, Chen Tian, Tingting Liu, Cuijuan Liu Aug 2020

Real Time Fluid Simulation Framework Based On Directcompute, Liu Lu, Liu Zhen, Gaoqi He, Chen Tian, Tingting Liu, Cuijuan Liu

Journal of System Simulation

Abstract: A real time fluid simulation framework based on DirectCompute acceleration was proposed to solve problems of low simulation efficiency that caused by the increasing fluid particle size and long processing time that caused by the complex solid-liquid boundary. In the simulation, a grid local collision detection method was adopted to speed up the search for the solid-liquid boundary. Fluid calculation, collision detection and surface reconstruction were computed parallel in the GPU with DirectCompute technology to accelerate the SPH fluid simulation. It could optimize the storage structure of fluid simulation, and save the storage space. Experimental results show that the …


Gpu-Accelerated Cloth Animation Based On Module Division, Kun Zhou, Liu Zhen, Gaoqi He, Chen Tian, Tingting Liu, Cuijuan Liu Aug 2020

Gpu-Accelerated Cloth Animation Based On Module Division, Kun Zhou, Liu Zhen, Gaoqi He, Chen Tian, Tingting Liu, Cuijuan Liu

Journal of System Simulation

Abstract: In order to improve the simulation speed of cloth animation, a module division parallel computing method was proposed by studying two kinds of cloth simulation models with dynamics and position based dynamics (PBD). A computing task was divided into a plurality of independent blocks by the way of data block. GPU parallel computing was used within the data block to improve the real-time performance and robustness of the cloth simulation. The applicability and effectiveness of the algorithm were verified under different scenarios and stochastic wind field. Experimental results show that under the same conditions, the proposed method can effectively …


Subdivision Algorithm For Computing The Minimum Distance Between Two Algebraic Curves, Jiadai Qi, Huahao Shou Aug 2020

Subdivision Algorithm For Computing The Minimum Distance Between Two Algebraic Curves, Jiadai Qi, Huahao Shou

Journal of System Simulation

Abstract: Since it is difficult to compute the minimum distance between two algebraic curves by traditional methods when the expressions of the algebraic curves are complicated, a subdivision algorithm is proposed. Quadtree data structure was used to subdivide the two algebraic curves into two sets of pixels. Interval arithmetic was used to compute the minimum distance interval between these two sets of pixels. The center of this interval is the approximation of the minimum distance between the two algebraic curves. The error is less than a half of this interval. Compared with traditional methods, this method can obtain the approximation …


Particle Swarm Optimization Method Based On Weighted Dynamic Constraints For Interactive Intelligent Fish Swarm, Xingquan Cai, Buni Honghao, Mengxuan Li, Fengxia Li Aug 2020

Particle Swarm Optimization Method Based On Weighted Dynamic Constraints For Interactive Intelligent Fish Swarm, Xingquan Cai, Buni Honghao, Mengxuan Li, Fengxia Li

Journal of System Simulation

Abstract: For particle swarm algorithm not being applied to the rapid evolution of virtual biological cluster in short range, a particle swarm optimization method was provided that oriented to interactive intelligent fish with weight dynamic constrained. This method let particle swarm through the state of the particle separation, and dynamic constraint particle swarm. This method used the concept of "convergence coefficient manager" to retain the differential movement between the particles. On this basis, setting the evaluation function and using the dynamic constraint weights, the fast particle swarm was completed, applying to virtual biological cluster. The experiments results show the best …


Rational Interpolation Skinning Surface Via Continued Fractions Interpolation Based On Partial Generalized Function Inverse, Huanxi Zhao Aug 2020

Rational Interpolation Skinning Surface Via Continued Fractions Interpolation Based On Partial Generalized Function Inverse, Huanxi Zhao

Journal of System Simulation

Abstract: A two-variable functions partial generalized inverse was proposed, and using the proposed partial generalized inverse, the partial inverse difference of two-variable functions was defined, and then based on the partial inverse difference. Thiele continued fraction interpolation algorithm for rational interpolation skinning surface and parameters rational interpolation spline skinning surface were proposed respectively. Interpolation recursion formula for the rational interpolation skinning surface was presented, and numerical simulation example illustrates the effectiveness of skinning surface modeling algorithm.


Multi-Scale Detection Method For Dense Crowd Target Detection, Jianxin Zhou, Jianjun Wu, Junqiang Xue, Lin Shuai, Dang Gang, Zhiquan Cheng Aug 2020

Multi-Scale Detection Method For Dense Crowd Target Detection, Jianxin Zhou, Jianjun Wu, Junqiang Xue, Lin Shuai, Dang Gang, Zhiquan Cheng

Journal of System Simulation

Abstract: A multi-scale algorithm was proposed to detect the targets flexibly. In coarse scale, an optimized DPM (Deformable Part Model) method was used to filter out sparse objectives that was represented by whole body. Then the whole scenario was cut into multiple finer regions and the Faster R-CNN (Region-based Convolutional Neural Network) method was trained and utilized to detect dense objects that was indicated by head in fine scale. These two detection results were incorporated via NMS (Non - Maximum Suppression) method, in order to supplement with each other and remove redundancy. The effectiveness of the proposed method has been …


Temporal Group Visualization Method For Pesticide Residue Detection Data, Hongqian Chen, Fang Yi, Qianyu Yang, Li Hui, Chen Yi Aug 2020

Temporal Group Visualization Method For Pesticide Residue Detection Data, Hongqian Chen, Fang Yi, Qianyu Yang, Li Hui, Chen Yi

Journal of System Simulation

Abstract: To show and compare more statistics in pesticide residue detection data, a temporal grouping visualization method was proposed. The method divided data set according to the hierarchy of data meaning. The stacked statistical likely figure was designed to watch data and its trending over time. The multidimensional data objects were grouped in the two-dimensional plane space layout. The scattered bubble charts was introduced to express the classification of agricultural products. Stacked bar graph was adopted to show the sequential sampled attribute data. Multi-fold rose diagram was designed to display comparably the pesticide detection result and its temporal attribute. Experimental …


Dynamic Water Surface Simulation Based On Secondary Reflection Mapping, Li Hua, Huamin Yang, Feng Xin Aug 2020

Dynamic Water Surface Simulation Based On Secondary Reflection Mapping, Li Hua, Huamin Yang, Feng Xin

Journal of System Simulation

Abstract: In order to improve the effects of dynamic water surface simulation, a method was proposed which utilized 3D mesh modeling water surface and was optimized by projective grid method; A mirror image of the subject above the water was generated which was called the first reflection map; then the simplified Navier-Stokes equation was enforced onto the first texture mapping. The reflection and refraction was calculated to form a secondary reflection map with respect to the perspective mapping coordiante; Perspective texture mapping was enforced to water surface to achieve fast simulated water surface. Experimental test shows that the approach can …


Virtual Modeling And Motion Simulation Of Under-Actuated Humanoid Multi-Fingered Hand, Yaopeng Zhang, Dangxiao Wang, Lijun Wang, Xikang Qian Aug 2020

Virtual Modeling And Motion Simulation Of Under-Actuated Humanoid Multi-Fingered Hand, Yaopeng Zhang, Dangxiao Wang, Lijun Wang, Xikang Qian

Journal of System Simulation

Abstract: With the increase of the number of upper limb disabilities, requirement of humanoid artificial hand is more and more. Under-actuated multi-fingered prosthetic hand based rope driving has simple and compact structure, light weight and it can shape-adaptively grip objects stably and flexibly according to the target object shape. The index finger and thumb for pinch and lateral pinch are very often operated in everyday life. So pinch and lateral pinch largely determine the success of prosthetic hand design. In the guise of the preliminary design stage, combination of the use of MATLAB modeling calculations, and ADAMS movement simulation can …


Composite Kalman Motion Estimation Method Based On Virtual Distance, Zhizhong Sun, Zehui Lu, Weiqing Li Aug 2020

Composite Kalman Motion Estimation Method Based On Virtual Distance, Zhizhong Sun, Zehui Lu, Weiqing Li

Journal of System Simulation

Abstract: MEMS inertial sensors applied to human motion capture, but because of the MEMS sensor system errors, the virtual people cannot operate precisely and stably. In order to achieve tracking the movement of an arm accurately, by analyzing the movement of a virtual arm, measuring the distance between the finger of the arm and the center of the object in virtual scene, combined with the virtual arm movement characteristics, a composite Kalman motion estimation method was designed. The model divided arm movement into a uniform model, a uniformly accelerated model and several typical phase models. Depending on the different distance …


Planning Model And Model Solve Method Of Multi-Base Multi -Uav Cooperative Reconnaiance, Li Yuan, Zhang Hui, Sijin Wu Aug 2020

Planning Model And Model Solve Method Of Multi-Base Multi -Uav Cooperative Reconnaiance, Li Yuan, Zhang Hui, Sijin Wu

Journal of System Simulation

Abstract: A UAV cooperative reconnaiance planning model with multi-base, multi-UAV, restrictions of target reconnaiance thime windows and target reconnaiance equipment was set up, and the model solve method was proposed. The take-off bases of the UAvs, the type of reconnaiance equipment carried and the target sequences reconnaianced by the UAVs were optimized in company in order to find the reconnaiance plan that need minimum number of UAVs. The process of signal plan forming was devided into two steps, the formation of the initial plan and the formation of the specific plan. The plans were ranked by the primary and secondary …


Heat Kernel Signature Extraction Algorithm Based On Mesh Simplification, Haisheng Li, Sun Li, Cai Qiang, Cao Jian Aug 2020

Heat Kernel Signature Extraction Algorithm Based On Mesh Simplification, Haisheng Li, Sun Li, Cai Qiang, Cao Jian

Journal of System Simulation

Abstract: Heat kernel signature has been proposed for 3D model feature extraction in recent years. However, the performance of heat kernel signature is inefficient, especially when the models have large number of vertices. Mesh simplification algorithm based on quadric error metrics was used to preprocess 3D model and the heat kernel signature was calculated based on the simplified model. Experiments show that the feature extracting time of the simplified model is less than the original model. The more vertices of the original model, the more obvious of the improved efficiency. The heat kernel signature of simplified model is consistent with …


Subject-Specific Body Segment Parameter Optimization, Lv Xiaolei, Shihong Xia Aug 2020

Subject-Specific Body Segment Parameter Optimization, Lv Xiaolei, Shihong Xia

Journal of System Simulation

Abstract: In conventional methods of physics based character animation, human model are approximated by the rigid body models. However, the human body parts are not as easily described as rigid bodies with defined joints and inflexible geometry, daily varying mass, etc. A body segment parameter optimization method based on the force plate data and motion capture data was proposed. This method optimized the body segment parameter iteratively using the Lagrange constraints based on the contact information and motion capture data. Different subjects took part in the motion capture process with various kinds of motions. A comprehensive evaluation was done for …


Design And Implementation Of Historical Figures Knowledge Graph Visualization System, Zhou Yi, Mingquan Zhou, Xuesong Wang, Youliang Huang Aug 2020

Design And Implementation Of Historical Figures Knowledge Graph Visualization System, Zhou Yi, Mingquan Zhou, Xuesong Wang, Youliang Huang

Journal of System Simulation

Abstract: With the advent of big data era, knowledge graph and data visualization technology present the data in a structured, visual way and establish a keyword-oriented knowledge system and render the relationship in a fast and clearly way. In this paper, a historical figures entity relationship visualization system has been established by means of data visualization and knowledge graph. In the system,the complex data are divided into character data and event data by data preprocessing. In the parsing stage, a label traversing method and a method based on weight of links are applied to the divided data respectively. With …


Visual Tsunami Simulation And Disaster Risk Assessment, Xie Cui, Jinjin Xun, Xiaowei Zhou, Junyu Dong Aug 2020

Visual Tsunami Simulation And Disaster Risk Assessment, Xie Cui, Jinjin Xun, Xiaowei Zhou, Junyu Dong

Journal of System Simulation

Abstract: Based on the effectively modeling and visual simulation of the potential tsunami event in the South China Sea, the tsunami generation, propagation, runup and inundation could be visually simulated with multiple scenarios. The inundation probability, the flood inundation area and degree were computed. The location and function of buildings/critical facilities in the study area were extracted and classified by GIS analysis and image processing technology. Then the population distribution was effectively modeled and the vulnerability of people response was estimated for risk assessment combining with the geographical information and the historical disasters record. This improved method considered the inundation …