Research on Random Fatigue Load Model of Highway Bridge by Vehicle Traffic Based on GMM

Highway bridges have often suffered accidents due to fatigue damage. This paper studies the influence of vehicle operating state on the fatigue performance of bridges. Based on GMM method and K-S test in information statistics, this paper proposes an improved Gaussian hybrid modelling method, and studies the various parameters of vehicle operating state on beam bridge fatigue, such as the impact of the damage and its fatigue life assessment. On this basis, the fatigue cumulative damage formula of multi-vehicle upper bridge is proposed. The traffic load of Shandong JiNan-QingDao expressway has been GMMly analysed by GMM. The Gaussian mixture model is used to fit the vehicle load probability function by standard fatigue vehicle model. Based on the expressway, the vehicle fatigue has been established to facilitate the fatigue load and evaluate the fatigue life. Gradually this paper helps to improve the accuracy and convenience of the probability model, which is conducive to the establishment of a scientific and efficient load probability model for road vehicles

Improved spatial–temporal graph convolutional networks for upper limb rehabilitation assessment based on precise posture measurement

After regular rehabilitation training, paralysis sequelae can be significantly reduced in patients with limb movement disorders caused by stroke. Rehabilitation assessment is the basis for the formulation of rehabilitation training programs and the objective standard for evaluating the effectiveness of training. However, the quantitative rehabilitation assessment is still in the experimental stage and has not been put into clinical practice. In this work, we propose improved spatial-temporal graph convolutional networks based on precise posture measurement for upper limb rehabilitation assessment. Two Azure Kinect are used to enlarge the angle range of the visual field. The rigid body model of the upper limb with multiple degrees of freedom is established. And the inverse kinematics is optimized based on the hybrid particle swarm optimization algorithm. The self-attention mechanism map is calculated to analyze the role of each upper limb joint in rehabilitation assessment, to improve the spatial-temporal graph convolution neural network model. Long short-term memory is built to explore the sequence dependence in spatial-temporal feature vectors. An exercise protocol for detecting the distal reachable workspace and proximal self-care ability of the upper limb is designed, and a virtual environment is built. The experimental results indicate that the proposed posture measurement method can reduce position jumps caused by occlusion, improve measurement accuracy and stability, and increase Signal Noise Ratio. By comparing with other models, our rehabilitation assessment model achieved the lowest mean absolute deviation, root mean square error, and mean absolute percentage error. The proposed method can effectively quantitatively evaluate the upper limb motor function of stroke patients

A survey on human performance capture and animation

With the rapid development of computing technology, three-dimensional (3D) human body models and their dynamic motions are widely used in the digital entertainment industry. Human perfor- mance mainly involves human body shapes and motions. Key research problems include how to capture and analyze static geometric appearance and dynamic movement of human bodies, and how to simulate human body motions with physical e�ects. In this survey, according to main research directions of human body performance capture and animation, we summarize recent advances in key research topics, namely human body surface reconstruction, motion capture and synthesis, as well as physics-based motion sim- ulation, and further discuss future research problems and directions. We hope this will be helpful for readers to have a comprehensive understanding of human performance capture and animatio

사람 동작의 마커없는 재구성

학위논문 (박사)-- 서울대학교 대학원 : 전기·컴퓨터공학부, 2017. 2. 이제희.Markerless human pose recognition using a single-depth camera plays an important role in interactive graphics applications and user interface design. Recent pose recognition algorithms have adopted machine learning techniques, utilizing a large collection of motion capture data. The effectiveness of the algorithms is greatly influenced by the diversity and variability of training data. Many applications have been developed to use human body as a controller to utilize these pose recognition systems. In many cases, using general props help us perform immersion control of the system. Nevertheless, the human pose and prop recognition system is not yet sufficiently powerful. Moreover, there is a problem such as invisible parts lower the quality of human pose estimation from a single depth camera due to an absence of observed data. In this thesis, we present techniques to manipulate the human motion data for enabling to estimate human pose from a single depth camera. First, we developed method that resamples a collection of human motion data to improve the pose variability and achieve an arbitrary size and level of density in the space of human poses. The space of human poses is high-dimensional and thus brute-force uniform sampling is intractable. We exploit dimensionality reduction and locally stratified sampling to generate either uniform or application-specifically biased distributions in the space of human poses. Our algorithm is learned to recognize such challenging poses such as sit, kneel, stretching and yoga using a remarkably small amount of training data. The recognition algorithm can also be steered to maximize its performance for a specific domain of human poses. We demonstrate that our algorithm performs much better than Kinect SDK for recognizing challenging acrobatic poses, while performing comparably for easy upright standing poses. Second, we find out environmental object which interact with human beings. We proposed a new props recognition system, which can applied on the existing human pose estimation algorithm, and enable to powerful props estimation with human poses at the same times. Our work is widely applicable to various types of controllers system, which deals with the human pose and addition items simultaneously. Finally, we enhance the pose estimation result. All the part of human body cannot be always estimated from the single depth image. In some case, some body parts are occluded by other body parts, and sometimes estimation system fail to success. For solving this problem, we construct novel neural network model which called autoencoder. It is constructed from huge natural pose data. Then it can reconstruct the missing parameter of human pose joint as new correct joint. It can be applied to many different human pose estimation systems to improve their performance.1 Introduction 1 2 Background 9 2.1 Research on Motion Data 9 2.2 Human Pose Estimation 10 2.3 Machine Learning on Human Pose Estimation 11 2.4 Dimension Reduction and Uniform Sampling 12 2.5 Neural Networks on Motion Data 13 3 Markerless Human Pose Recognition System 14 3.1 System Overview 14 3.2 Preprocessing Data Process 15 3.3 Randomized Decision Tree 20 3.4 Joint Estimation Process 22 4 Controllable Sampling Data in the Space of Human Poses 26 4.1 Overview 26 4.2 Locally Stratified Sampling 28 4.3 Experimental Results 34 4.4 Discussion 40 5 Human Pose Estimation with Interacting Prop from Single Depth Image 48 5.1 Introduction 48 5.2 Prop Estimation 50 5.3 Experimental Results 53 5.4 Discussion 57 6 Enhancing the Estimation of Human Pose from Incomplete Joints 58 6.1 Overview 58 6.2 Method 59 6.3 Experimental Result 62 6.4 Discussion 66 7 Conclusion 67 Bibliography 69 초록 81Docto

Kinect Posture Reconstruction Based on a Local Mixture of Gaussian Process Models

Depth sensor based 3D human motion estimation hardware such as Kinect has made interactive applications more popular recently. However, it is still challenging to accurately recognize postures from a single depth camera due to the inherently noisy data derived from depth images and self-occluding action performed by the user. In this paper, we propose a new real-time probabilistic framework to enhance the accuracy of live captured postures that belong to one of the action classes in the database. We adopt the Gaussian Process model as a prior to leverage the position data obtained from Kinect and marker-based motion capture system. We also incorporate a temporal consistency term into the optimization framework to constrain the velocity variations between successive frames. To ensure that the reconstructed posture resembles the accurate parts of the observed posture, we embed a set of joint reliability measurements into the optimization framework. A major drawback of Gaussian Process is its cubic learning complexity when dealing with a large database due to the inverse of a covariance matrix. To solve the problem, we propose a new method based on a local mixture of Gaussian Processes, in which Gaussian Processes are defined in local regions of the state space. Due to the significantly decreased sample size in each local Gaussian Process, the learning time is greatly reduced. At the same time, the prediction speed is enhanced as the weighted mean prediction for a given sample is determined by the nearby local models only. Our system also allows incrementally updating a specific local Gaussian Process in real time, which enhances the likelihood of adapting to run-time postures that are different from those in the database. Experimental results demonstrate that our system can generate high quality postures even under severe self-occlusion situations, which is beneficial for real-time applications such as motion-based gaming and sport training