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Cheng S.,Zhejiang University of Technology | Cheng S.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Cheng S.,Carnegie Mellon University | Sun Z.,Zhejiang University of Technology
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics | Year: 2014

Previous eye trackers had complex structure, huge size and weight, and are only desktop oriented. To support ubiquitous computing and mobile interaction, an approach for eye tracking based on pupil center cornea reflection is introduced. The approach includes image processing, features detection, data processing and interaction application. Image filtering and binarization are used first. And then the improved algorithm of ellipse fitting and template matching is used to detect pupil and Purkinje images respectively. Finally, eye-movement data can be calculated, such as fixation's coordinates. A head mounted eye tracker prototype is presented, and the results of user study indicates it is not uncomfortable for users, and has high accuracy and robustness. It furthermore demonstrates the feasibility and effectiveness for the eye tracking based mobile interaction. Source

Ding W.,Zhejiang University of Technology | Ding W.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Hu C.,Zhejiang University of Technology | Cheng Z.,Zhejiang University of Technology | Xu L.,Zhejiang University of Technology
Nongye Gongcheng Xuebao/Transactions of the Chinese Society of Agricultural Engineering | Year: 2013

The plant simulation based on computer modeling and visualization has become an important topic in the scientific researches, such as the researches of computer graphics, agroforestry, and ecology. Due to the complexities of plant structure, especially in the modeling of large-scale scenes of natural environments, how to quickly and efficiently establish models of the scenes using computers has been a research focus in the area of plant modeling. It is a key step to select appropriate morphogenetic model to simulate morphology and architecture in plant modeling. However, it is needed to artificially extract the parameters of the model based on the priori knowledge of the plants in order to simulate the realistic plant morphology as required, no matter what kind of morphogenetic model is chosen. Larger number of parameters for the rules will be needed in the modeling of large-scale scenes. Extraction of the parameters for the rules based on the artificial method is time-consuming and laborious. Thus it is particularly important to develop a method for efficiently extracting the rule parameters in simulating different types of plants. In this study, an intelligent method for simulating and visualizing plant shape was proposed, aiming at solving the problems caused by blindness and low efficiency when only using L-systems to simulate plant shapes by manual way. The production rules and the initial axioms of the model with L-systems were obtained by this method. Then the spatial structure of specific plants based on the concepts of gene expression programming was simulated. We proposed a restrictive strategy to design the initial population with the control of the branch number and the morphology of individuals, which can be used to guide the evolution of simulated plants towards the target shape and reduce the searching scope with the algorithm. The method was developed based on the analysis of previous studies, the most of which were using traditional genetic algorithms to generate the initial population in a completely random way. Besides, we proposed a selecting strategy to automatically select the optimal individuals in each generation, and thus preserve better traits of the population, which can further improve the efficiency of the algorithm. Using the genetic manipulations to simulate the evolution processes, i.e. one point crossover, two point crossover, gene recombination, transposition, and mutation, the population with morphological diversity can be generated. We also proposed an individual fitness evaluation function which is integrated algorithm of plant outline comparison with Hausdorff distance calculation method. Combined the fitness evaluation function with the proposed evolutional algorithm, the optimal individuals in each generation can be selected, so that the evolution speed can be increased greatly. The method proposed in this study has been implemented with the graphics hardware, NVIDIA GeForce3, using OpenGL functions. The simulation results indicate that the proposed methods can not only simulate the special plant morphology, but also the normal plant morphology with various types. The method will promote the development of plant simulation models and also provide a reference in the exploring of new methods for virtual plant modeling. Source

Pan J.,Zhejiang University of Technology | Pan J.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Dai X.T.,Zhejiang University of Technology | Xu X.Q.,Zhejiang University of Technology | Lou Y.C.,Zhejiang GongShang University
Applied Mechanics and Materials | Year: 2013

At present, arrival time information service and security supervision of public transit vehicles have become a hot issue of society and government departments. In this paper, a system for notifying passengers waiting for buses of the status of the vehicles, including the arrival times of vehicles at stops, is proposed. The system includes GPS devices located in the vehicles for determining the location of the vehicles along their routes. A server is coupled to the GPS devices for receiving the locations of vehicles, computing the arrival times of vehicles based on history data model, and publishing the information on website using RESTful API. Experiments on real datasets show that the system is a powerful tool for arrival time prediction of public transit vehicles. © (2013) Trans Tech Publications, Switzerland. Source

Tang Y.,Zhejiang University of Technology | Tang Y.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Zhang Y.,Zhejiang University of Technology | Shi X.,Hangzhou Dianzi University | And 2 more authors.
Science China Information Sciences | Year: 2015

Artistic video stylization, which is widely used in multimedia entertainment, transforms a given video into different artistic styles. Most of the existing video stylization algorithms can simulate single or limited video artistic styles. Although some algorithms can achieve multi-style video processing, these algorithms are complex and difficult to implement. To solve this problem, we propose a multi-styled video stylization algorithm based on texture advection, where different artistic styles are synthesized and transferred from user-specified texture samples of desired styles. We use the direction field-guided texture synthesis to compute the texture layer that represents the artistic style. Painterly directional video styles are simulated competently by the orientation changes in the synthesized anisotropic textures. There appeared local distorted region of the texture layer during texture advection under the optical flow field. To address this issue, we propose the texture inpaint to synthesize the limited distorted region and make the stylized video temporally coherent. We also accelerate the video stylization by using the CUDA parallel computing framework that parallelly computes the morphological operations used for video abstraction. Finally, we produce stylized videos of multiple artistic styles with satisfactory experimental results, including the styles of oil painting, watercolor painting and stylized lines drawing. © 2015 Science China Press and Springer-Verlag Berlin Heidelberg Source

Gong W.,Zhejiang University of Technology | Gong W.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Yang L.,Zhejiang University of Technology | Yang L.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | And 2 more authors.
Journal of Computational Information Systems | Year: 2013

Resource searching is the first and foremost challenge in unstructured P2P networks. Although having received a lot of attentions during past few years, many proposed search methods still can't avoid some serious drawbacks such as high cost and low effciency in dynamic P2P environment. To resolve these weaknesses, this paper proposes an e?cient Query Routing Tree (QRT) algorithm based on maximum mutual information to improve the performance of resource searching, which has tightly associated the resource contents of peers with the logical links of P2P network. The primary benefits are that our proposed QRT algorithm can make the query messages forwarded more effectively in similar peers and hit more target resources faster. The experimental results show that our proposed QRT algorithm can decrease the search cost more effectively and maintain higher targets hit rate compared to Flooding, k-RW and APS algorithms, and the QRT algorithm is also proved to conduct high searching performance with better scalability in unstructured P2P networks. © 2013 Binary Information Press. Source

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