Fast and reliable recognition of human motion from motion trajectories using wavelet analysis

Recognition of human motion provides hints to understand human activities and gives opportunities to the development of new human-computer interface. Recent studies, however, are limited to extracting motion history image and recognizing gesture or locomotion of human body parts. Although the approach employed, i.e. the transformation of the 3D space-time (x-y-t) analysis to the 2D image analysis, is faster than analyzing 3D motion feature, it is less accurate and less robust in nature. In this paper, a fast trajectory-classification algorithm for interpreting movement of human body parts using wavelet analysis is proposed to increase the accuracy and robustness of human motion recognition. By tracking human body in real time, the motion trajectory (x-y-t) can be extracted. The motion trajectory is then broken down into wavelets that form a set of wavelet features. Classification based on the wavelet features can then be done to interpret the human motion. An online hand drawing digit recognition system was built using the proposed algorithm. Experiments show that the proposed algorithm is able to recognize digits from human movement accurately in real time.postprintThe 2004 IFIP International Conference on Artificial Intelligence Applications and Innovation, Toulouse, France, 22-27 August 2004. In Proceedings of the IFIP International Conference on Artificial Intelligence Applications and Innovation, 2004, p. 1-1

Segmenting lumbar vertebrae in digital video fluoroscopic images through edge enhancement

Video fluoroscopy provides a cost effective way for the diagnosis of low back pain. Backbones or vertebrae are usually segmented manually from fluoroscopic images of low quality during such a diagnosis. In this paper, we try to reduce human workload by performing automatic vertebrae detection and segmentation. Operators need to provide the rough location of landmarks only. The proposed algorithm will perform edge detection, which is based on pattern recognition of texture, along the snake formed from the landmarks. The snake will then attach to the edge detected. Experimental results show that the proposed system can segment vertebrae from video fluoroscopic image automatically and accurately. © 2004 IEEE.published_or_final_versio

Reliable and fast human body tracking under information deficiency

Session MA-4 System Identification and Pattern Recognition IHuman body tracking is useful in applications like medical diagnostic, human computer interface, visual surveillance etc. In most cases, only rough position of the target is needed, and blob tracking can be used. The blob region is located within a searching window, which is shifted and resized in each frame based on previous observations. The observations are the locations of the blob in the frames, and are fed into an estimator for predicting the position and the size of the searching window. However, a blob region is regarded as a noisy observation, and the information provided by the blob observation is deficient for most estimators to work well. In this paper, a reliable and efficient estimation algorithm using wavelet is proposed to track human body under information deficiency. The human body is located roughly within a small searching window using color and motion as heuristics. The location and the size of the searching window are estimated using the proposed wavelet estimation scheme. Experimental results show that human body can be tracked accurately and efficiently using the proposed method. The tracker works well in various conditions like clutter background, and background with distractors.published_or_final_versionThe 2003 IEEE Intelligent Automation Conference (2003年中国智能自动化会议), Hong Kong, 15-17 December 2003. In Proceedings of the IEEE Intelligent Automation Conference, 2003, p. 491-49

Robust image segmentation by texture sensitive snake under low contrast environment

Robust image segmentation plays an important role in a wide range of daily applications, like visual surveillance system, computer-aided medical diagnosis, etc. Although commonly used image segmentation methods based on pixel intensity and texture can help finding the boundary of targets with sharp edges or distinguished textures, they may not be applied to images with poor quality and low contrast. Medical images, images captured from web cam and images taken under dim light are examples of images with low contrast and with heavy noise. To handle these types of images, we proposed a new segmentation method based on texture clustering and snake fitting. Experimental results show that targets in both artificial images and medical images, which are of low contrast and heavy noise, can be segmented from the background accurately. This segmentation method provides alternatives to the users so that they can keep using imaging device with low quality outputs while having good quality of image analysis result.postprintThe International Conference on Informatics in Control, Automation and Robotics, Setúbal, Portugal, 25-28 August 2004. In Proceedings of the International Conference on Informatics in Control, Automation and Robotics, 2004, p. 430-43

Cantonese consonantal development: towards a nonlinear account

Descriptions of the development of prosodic and segmental tiers of children's phonological systems have been derived from investigations of the development of English. This paper provides a preliminary description of phonological tier development in Cantonese-speaking children. Eight children, (two each at 1;7, 2;6, 3;5, and 4;2 years) named 95 pictures. The data were analysed for word, syllable, onset-rime, skeletal, and segmental tiers. The results suggested a developmental order in the acquisition of hierarchical features. Decreasing order of accuracy of the tiers was word = syllable > onset-rime = skeletal > segmental. A model of feature geometry was adopted to describe the acquisition of features. An interesting finding is the way the laryngeal feature (aspiration) was combined with place contrasts one at a time rather than all at once.published_or_final_versio

Conservation form of Helbing's fluid dynamic traffic flow model

A standard conservation form is derived in this paper. The hyperbolicity of Helbing's fluid dynamic traffic flow model is proved, which is essential to the general analytical and numerical study of this model. On the basis of this conservation form, a local discontinuous Galerkin scheme is designed to solve the resulting system efficiently. The evolution of an unstable equilibrium traffic state leading to a stable stop-and-go traveling wave is simulated. This simulation also verifies that the model is truly improved by the introduction of the modified diffusion coefficients, and thus helps to protect vehicles from collisions and avoide the appearance of the extremely large density. © 2011 Shanghai University and Springer-Verlag Berlin Heidelberg.postprin

Tracking Lumbar Vertebrae in Digital Videofluoroscopic Video Automatically

Low back pain becomes one of the significant problem in the industrialized world. Efficient and effective spinal motion analysis is required to understand low back pain and to aid the diagnosis. Videofluoroscopy provides a cost effective way for such analysis. However, common approaches are tedious and time consuming due to the low quality of the images. Physicians have to extract the vertebrae manually in most cases and thus continuous motion analysis is hardly achieved. In this paper, we propose a system which can perform automatic vertebrae segmentation and tracking. Operators need to define exact location of landmarks in the first frame only. The proposed system will continuously learn the texture pattern along the edge and the dynamics of the vertebrae in the remaining frames. The system can estimate the location of the vertebrae based on the learnt texture and dynamics throughout the sequence. Experimental results show that the proposed system can segment vertebrae from videofluoroscopic images automatically and accurately. © Springer-Verlag 2004.postprintThe International Workshop on Medical Imaging and Augmented Reality (MIAR 2004), Beijing, China, 19-20 August 2004. In Lecture Notes in Computer Science, 2004, v. 3150, p. 154-16

Persistent hypocalcaemia in a Chinese girl due to a novel de-novo activating mutation of the calciumsensing receptor gene

A significant proportion of patients formerly diagnosed with idiopathic hypoparathyroidism actually have activating mutation of the calcium-sensing receptor (CaSR) gene. Awareness of the possibility of activating mutation of CaSR gene in patients with sporadic idiopathic hypoparathyroidism is important because of its relevance to clinical management. This report is of a novel activating mutation of the CaSR gene identified in a 10-year-old Chinese girl who was initially diagnosed as having idiopathic hypoparathyroidism at 6 years of age after presenting with seizures. Her serum calcium level was difficult to maintain near the lower limit of normal despite treatment with high-dose calcitriol. Treatment with calcitriol produced significantly elevated urinary calcium-to-creatinine ratio. Direct sequencing of the CaSR gene showed a novel heterozygous mutation (p.Q735P (c.2204A>C)). Molecular genetic analysis of her parents demonstrated that both parents did not harbour the child's mutation, indicating that her mutation had arisen de novo. © 1995-2011 HKAM.published_or_final_versio

Optional elements and variant structures in the productions of bei2 to give dative constructions in Cantonese-speaking adults and three-year-old children

To express object transfer, Cantonese-speakers use a ditransitive ([V-R-T] or [V-T-R] where V=Verb, T=Theme, R=Recipient), or a more complex prepositional/serial-verb (P/SV) construction. Clausal elements in Cantonese datives can be optional (resulting in full versus non-full forms) or appear in variant orders (full non-canonical and full canonical). We report on usage of dative constructions with the word bei2 to give in 86 parents and 53 three-year-old children during conversations. The parents used more P/SV than ditransitive bei2-datives, and vice versa for the children. Both groups showed a similar usage pattern of optional elements and variant structures in their ditransitive and P/SV bei2-datives. The roles of multiple construction types, optional elements and variant structures in children's learning of bei2-dative constructions are described. Copyright © 2009 Cambridge University Press.published_or_final_versio

Tourism demand forecasting : a time varying parameter error correction model

Accepted ManuscriptPublishe