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Yang L.,Zhejiang University of Technology | Yang L.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Zhou J.,Zhejiang University of Technology | Gong W.,Zhejiang University of Technology | Chen L.,Peking University
Jisuanji Yanjiu yu Fazhan/Computer Research and Development | Year: 2013

Much attention has recently been put on the energy-saving scheme for heterogeneous drive (H-Drive) which combines SSD and HDD. This paper focuses on the energy-efficient file buffering schemes for H-Drive while ensuring disk's lifespan. We propose a frequency-energy based replacement scheme (FEBR for short) by adapting previous replacement algorithm FBR with the help of an energy-cost model. And based on the sliding-window scheme, we also present a self-adaptive disk power management scheme by taking the disk lifespan into account, which adjusts timeout threshold according to the statistical behavior of user accesses. To explore the applicability of the existing replacement schemes ranging from page-based to file-based buffering scheme, we evaluate their effectiveness on energy-efficiency, performance, and HDD lifetime and compare them with our proposed scheme. With extensive experiments on four real-world file usage traces collected in our office, some useful conclusions are drawn: energy-saving in H-Drive is feasible, it can reach as high as 70%~80%; FBR and its variant FEBR, and GDS are the best ones among all those online buffering schemes evaluated while FEBR has some advantages over FBR and GDS; the proposed self-adaptive disk power management scheme can effectively control the disk's lifetime and it is inappropriate to power disk on or off by using those fixed-timeout threshold scheme prevailed previously.


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.


Ding W.,Zhejiang University of Technology | Ding W.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Jin H.,Zhejiang University of Technology | Xu L.,Zhejiang University of Technology | And 2 more authors.
Communications in Computer and Information Science | Year: 2012

Group of plants, such as forest, grass-land, and garden, are necessary parts of natural scenes. Due to the large varieties and their natural complexity in geometry, modeling and rendering of large scenes with many plants are difficult and with challenge, which are limited by the capabilities of current graphics hardware. The objective of this study is to present a fast algorithm to simulate a virtual tomato garden based on GPUs acceleration. Parametric L-system is used to describe the topological structure of individual tomato plants. Vertex shader and fragment shader are utilized to do the computing of graphical interpretation of generated strings and the calculation of texture, light, and color of different organs, respectively. Moreover, level of detail is employed to describe different simulation level according to distance between the plant position and the viewpoint. The experiment results show that the proposed method can not only simulate the natural scene of tomato garden, but also can visually simulate the interactive behaviors between tomato plants and environmental factors. © 2012 Springer-Verlag.


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


Gong W.,Zhejiang University of Technology | Gong W.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Jin R.,Zhejiang Sci-Tech University | Yang L.,Zhejiang University of Technology | And 3 more authors.
Chinese Journal of Electronics | Year: 2015

How to find desired resources efficiently and accurately is one fundamental challenge of any unstructured P2P networks, which is mainly involved some difficulties in the P2P overlay topology, data representation in peers and routing mechanism. In this paper, we address the issue of resilient routing in unstructured P2P networks. An efficient algorithm called Query routing tree (QRT) based on maximum mutual information is proposed to improve the performance of resource searching, which has tightly associated the resource contents of peers with the logical links in P2P network that makes the query messages forwarded more effectively in similar peers and can hit more target resources faster. Additionally, we present an optimized routing scheme with the query conditions taken into account, to obtain the optimal routing tree with the minimal information gain from the candidate tree set so as to adapt to different query types more flexibly. The simulation results show the proposed QRT can reduce the search cost more effectively and maintain higher targets hit rate than existing typical algorithms such as Flooding, k-RW and APS. Finally, our optimized scheme is also proved to conduct high searching performance with nicer self-adaptability and scalability in unstructured P2P networks. © 2015 Chinese Institute of Electronics.


Shen Y.,Zhejiang University of Technology | Shen Y.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Zhao L.,Zhejiang University of Technology | Zhao L.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | And 2 more authors.
Information (Switzerland) | Year: 2015

Taxi GPS traces, which contain a great deal of valuable information as regards to human mobility and city traffic, can be extracted to improve the quality of our lives. Since the method of visualized analysis is believed to be an effective way to present information vividly, we develop our analysis and visualization method based on a city's short-dated taxi GPS traces, which can provide recommendation to help cruising taxi drivers to find potential passengers with optimal routes. With our approach, hot spots for loading and unloading passenger(s) are extracted using an improved DBSCAN algorithm after data preprocessing including cleaning and filtering. Then, this paper describes the start-end point-based similar trajectory method to get coarse-level trajectories clusters, together with the density-based e distance trajectory clustering algorithm to identify recommended potential routes. A weighted tree is defined including such factors as driving time, velocity, distance and endpoint attractiveness for optimal route evaluation from vacant to occupied hot spots. An example is presented to show the effectiveness of our visualization method. © 2015 by the authors.


Wang X.,Zhejiang University of Technology | Wang X.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Chen Q.,Zhejiang University of Technology | Chen Q.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | And 2 more authors.
Computational and Mathematical Methods in Medicine | Year: 2014

The ways to compute the kinematics and dynamic quantities of human bodies in motion have been studied in many biomedical papers. This paper presents a comprehensive survey of 3D human motion editing and synthesis techniques. Firstly, four types of methods for 3D human motion synthesis are introduced and compared. Secondly, motion capture data representation, motion editing, and motion synthesis are reviewed successively. Finally, future research directions are suggested. © 2014 Xin Wang et al.


Wang X.,Zhejiang University of Technology | Wang X.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | Chen Q.,Zhejiang University of Technology | Chen Q.,Key Laboratory of Visual Media Intelligent Process Technology of Zhejiang Province | And 2 more authors.
Jisuanji Fuzhu Sheji Yu Tuxingxue Xuebao/Journal of Computer-Aided Design and Computer Graphics | Year: 2014

This paper proposes to combine multi-character deformable motion model and motion patches to synthesize multi-character animations. In the stage of constructing motion patches, multi-character deformable motion model is adopted to construct a patch library which consist of patches with same semantic meanings but different motion details. In the stage of tiling motion patches, a strategy combining the random sample consensus algorithm and the deterministic search algorithm is used to tile the motion patches. In the stage of multi-character motion synthesis, the top-down strategy is used to match the case with the environmental constraints, and the large patches with higher priority strategy is used to match the case that the shape of patches is irregular. The experimental results show that the proposed method can achieve a smooth transition between motion patches and a seamless splice diagram, which results in animations continuous in time and no-overlapping in space.


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.


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.

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