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There is an increasing demand to develop image processing tools for the filtering and analysis of matrix-valued data, so-called matrix fields. In the case of scalar-valued images parabolic partial differential equations (PDEs) are widely used to perform filtering and denoising processes. Especially interesting from a theoretical as well as from a practical point of view are PDEs with singular diffusivities describing processes like total variation (TV-) diffusion, mean curvature motion and its generalisation, the so-called self-snakes. In this contribution we propose a generic framework that allows us to find the matrix-valued counterparts of the equations mentioned above. In order to solve these novel matrix-valued PDEs successfully we develop truly matrix-valued analogs to numerical solution schemes of the scalar setting. Numerical experiments performed on both synthetic and real world data substantiate the effectiveness of our matrix-valued, singular diffusion filters. [ABSTRACT FROM AUTHOR]

In the standard scale space approach one obtains a scale space representation u:ℝ of an image $f \in \mathbb{L}_{2}(\mathbb{R}^d)$ by means of an evolution equation on the additive group (ℝd, + ). However, it is common to apply a wavelet transform (constructed via a representation $\mathcal{U}$ of a Lie-group G and admissible wavelet ψ) to an image which provides a detailed overview of the group structure in an image. The result of such a wavelet transform provides a function $g \mapsto (\mathcal{U}_{g}\psi,f)_{\mathbb{L}_{2}(\mathbb{R}^2)}$ on a group G (rather than (ℝd, + )), which we call a score. Since the wavelet transform is unitary we have stable reconstruction by its adjoint. This allows us to link operators on images to operators on scores in a robust way. To ensure $\mathcal{U}$-invariance of the corresponding operator on the image the operator on the wavelet transform must be left-invariant. Therefore we focus on left-invariant evolution equations (and their resolvents) on the Lie-group G generated by a quadratic form Q on left invariant vector fields. These evolution equations correspond to stochastic processes on G and their solution is given by a group convolution with the corresponding Green's function, for which we present an explicit derivation in two particular image analysis applications. In this article we describe a general approach how the concept of scale space can be extended by replacing the additive group ℝd by a Lie-group with more structure. [ABSTRACT FROM AUTHOR]

In this study results gained for different electrode array schemes are compared which are used to image the activation time of the heart in a noninvasive way. The tested arrays have been selected based on sensitivity and effort-gain analysis. A cellular automaton was used for generating 6 different patterns resembling a sinus rhythm overlaid by an accessory pathway. The BSP was computed using a finite element approach. For generating the AT maps a boundary element model was used. It was found that methods for noninvasive imaging of the cardiac electrophysiology can profit from the increased details and features contained in the BSP maps recorded by a 125 lead array. [ABSTRACT FROM AUTHOR]

A large variety of techniques has been developed to visualize vascular structures. These techniques differ in the necessary preprocessing effort, in the computational effort to create the visualizations, in the accuracy with respect to the underlying image data and in the visual quality of the result. In this overview, we compare 3D visualization methods and discuss their applicability for diagnosis, therapy planning and educational purposes. We consider direct volume rendering as well as surface rendering. In particular, we distinguish model-based approaches, which rely on model assumptions to create "idealized" easy-to-interpret visualizations and model-free approaches, which represent the data more faithfully. Furthermore, we discuss interaction techniques to explore vascular structures and illustrative techniques which map additional information on a vascular tree, such as the distance to a tumor. Finally, navigation within vascular trees (virtual angioscopy) is discussed. Despite the diversity and number of existing methods, there is still a demand for future research which is also discussed. [ABSTRACT FROM AUTHOR]

Web-based technology has already been adopted as a tool to support teaching and learning in higher education. One criterion affecting the usability of such a technology is the design of web-based interface (WBI) within web-based learning programs. How different users access the WBIs has been investigated by several studies, which mainly analyze the collected data using statistical methods. In this paper, we propose to analyze users' learning behavior using Data Mining (DM) techniques. Findings in our study show that learners with different cognitive styles seem to have various learning preferences, and DM is an efficient tool to analyze the behavior of different cognitive style groups. [ABSTRACT FROM AUTHOR]

Several research efforts suggest that collaborative participatory simulations improve teaching and learning, increasing motivation inside the classroom. Currently, it has been mainly applied with students of primary and secondary educational levels, leaving higher level students aside. This paper presents a platform for implementing participatory simulations, where social interactions and motivational effects are the main facilitators. An instance of this platform was implemented for medicine school undergraduate students. Its implementation is simple, lightweight, fully based on pen-based interaction, and designed to work with handhelds and tablet-PC over an ad-hoc wireless network. The platform is able to support any kind of application implementing participatory simulation based on the exchange of artifacts among the learners. Keywords: Techniques, methods and tools for CSCW in design. Other Keywords: Handhelds. Collaborative Learning. Participatory Simulation. Learning Motivation. Gestures. Sketches. Freehand-input based. [ABSTRACT FROM AUTHOR]

A crucial issue for grid-based virtual wargame collaborative environment is that of mapping federate jobs to grid nodes efficiently. Because there exits large amount of interactions among federates, it is a challenging work to design an efficient federate mapping strategy. In this paper, we established an objective function for federate job mapping which takes into consideration not only the load of grid nodes, but also network utilization. Experimental results show that the proposed federate job mapping strategy can contribute to load balancing of the virtual wargame collaborative environment. [ABSTRACT FROM AUTHOR]

This paper describes an Augmented Reality based approach for use in museums and science centers for explanation, which is designed to improve visitors understanding. The distributed Augmented Reality system uses hybrid tracking technologies to detect the position and orientation of the museum visitor and measures a specific exhibit state with data acquisition sensors. Furthermore, we enhanced our system with an Augmented video streaming technology for remote participation and we developed the Mixed Reality Interface Markup Language (MRIML) to support high-level, platform independent scenario specification. [ABSTRACT FROM AUTHOR]

The paper reports how to assist university learners to study TRIZ, which is a series of useful tools, methods and strategies for solving inventive problems systematically, by means of computer games. The aim of this project is to help players to practice and understand their basic TRIZ knowledge and technique effectively and efficiently by playing online mini games. The paper goes through several major tools of TRIZ, Inventive Principles, Trends of Evolution, Contradiction and Engineering Parameters, and finally evaluates their educational and entertainment values to the player in terms of level design, feedback and interaction. [ABSTRACT FROM AUTHOR]

In recent years, many researchers are attracted to computer games research. Capable gamers can easily get bored, while beginners tend to give up after trying several times because the game does not correspond to their level of interest. Therefore, this paper proposes that the user's play pattern to be modeled on the basis of probability and level designer will dynamically generates the gaming level accordingly. We analyze user's play pattern and design pattern based on GMM (probability model) and dynamically generate the level with online learning technique adapting the reinforcement technique. The play pattern is modeled using GMM and in order to create game level dynamically, the method of updating the weight of enemy creation using online script is proposed. Finally, we apply our proposed method to a 2D shooting game and introduce user's play pattern leading to design pattern in the game. [ABSTRACT FROM AUTHOR]

With the development of simulation scalability, federates of various abilities are required to cooperate in a virtual environment. Restricted to HLA(High Level Architecture) standard, all the subscribing federates have to process the same traffic from an virtual object. As a result, existing RTI(Run-Time Infrastructure) software cannot conduct flow control on low-bandwidth federates. This paper suggests to reduce the object updating frequency and to restrict the update interval based on LoI(Layer of Interest) according to the host bandwidth. A bandwidth adaptive flow control model was built on the basis of LoI. This model depicts the way to conduct flow control with fidelity guarantee. Flow control algorithms are proposed to drop update packets according to the object LoI and packet LoI. Experiments illustrated that the flow control model can cut down the federate bandwidth requirements. [ABSTRACT FROM AUTHOR]

A programmable graphics pipeline including the shader in the embedded systems increases flexibility and enables customizations of vertex and fragment processing, and it also provides the programmer with various special effects essential in development of realistic 3D mobile games whereas the traditional fixed-function pipeline does not. In this paper, we design a unified shader integrating vertex shader and fragment shader, define a memory structure for the unified shader, and present an operating process to construct the memory structure and execute compiled shader program by passing it to the unified shader using the OpenGL ES 2.0 APIs. We are satisfied with the result from implementing the unified shader and its OpenGL ES 2.0 APIs. It can be used as a development platform for 3D mobile games. [ABSTRACT FROM AUTHOR]

Recently, research on augmented games as a new game genre has attracted a lot of attention. An augmented game overlaps virtual objects in an augmented reality(AR) environment, allowing users to interact with the AR environment through manipulating real and virtual objects. However, it is difficult to release existing augmented games to ordinary gamers, as the games generally use very expensive and inconvenient ‘backpack' systems. Accordingly, this paper introduces an augmented game, called augmented galaga based on traditional well-known galaga, executed on mobile devices to make game players experience the game without any economic burdens. Augmented galaga uses real space, such as a room, as game environment, and covers the real widespace with a small screen of mobile devices by actually moving the mobile devices. In an initial stage, the specific objects are selected by game players, and are automatically recognized by scale-invariant features in playing a game. Then, virtual insect-like aliens randomly appear in several specific regions displayed on the mobile screen, and game players attack it by moving the mobile devices towards specific regions with virtual aliens and clicking a button of mobile devices. As a result, we expect that augmented galaga provides an exciting experience without any economic burdens for players based on the game paradigm, where the user interacts with both the physical world captured by a mobile camera and the virtual aliens automatically generated by a mobile device. [ABSTRACT FROM AUTHOR]

CSCL systems are valuable supports for distance and face to face learners as well. With the aim of offering the accurate information to learners, the graphical interface of the environment has to be designed in a manner that it offers the right elements to participate and understand the collaboration in the environment. The aim of this paper is to offer the design of a discovery learning environment called Co-Lab and how the collaborative graphical interface has been built on it. [ABSTRACT FROM AUTHOR]

In recent years, thousands or even hundreds of thousands players interact with each other in the MMOG (Massively Multi-player Online Game). Therefore MMOG servers have the problem with scalability. To overcome this problem, we propose a new method for MMOG distributed server, denoted as 2Layer-Cell method. 2Layer-Cell method constructed with Upper_Layer and Down_Layer. The Upper_Layer includes important aggregated informationof game objects such as virtual space, users, monster, etc. And the Down_layer includes real data of game objects. This paper makes the following contributions. First, it captures these problems of high storage cost and slow processing time for previous methods. Second, it proposes parallel processing strategies that aim to reduce process time. Third, it proposes an efficient partitioning algorithm for distributed servers. Our experiment results show that our method is better scalable than existing methods. [ABSTRACT FROM AUTHOR]

In a NVE like massively multi-player online game, messages of participants should be synchronized. A solution for the synchronization problem is to wait for a certain amount of time until the server processes the messages, however determining a suitable waiting period is not easy because of the trade-off between the fairness and the responsiveness. In this paper, we develop methods to determine the waiting period using the probability of interaction among participants and ranks of delays of participants. Our methods take advantages of the property that, in a game with geographical map, each participant usually interacts with the participants around him. We built a NVE for simulation and compare proposed methods with popular method that uses the maximum expected delay as the waiting period. The experiment shows that the proposed method produces better result with lower average unfair ratio while keeping the same responsiveness, resulting in better synchronization mechanism. [ABSTRACT FROM AUTHOR]

In this paper, we mainly present the analysis on the haptic data transmission over real network conditions in a networked haptic collaboration environment. Since haptic data are produced at the rate of 1khz, the transmission of haptic data is extremely sensitive to packet loss, and time variation. We took some experiments for transferring haptic data under various network conditions such as packet loss, time delay and jitter. The experiments lead us to find that the unstable network conditions can cause the problems of inconsistent view and irregular force feedback in networked haptic applications. In order to overcome those problems, we tried to use a simple linear prediction algorithm for the haptic data transmission and the simple prediction algorithm shows better performance. In conclusion, a simple prediction algorithm can be a reasonable solution for the haptic data compensation in networked haptic applications. [ABSTRACT FROM AUTHOR]

This study developed a synchronous scaffolding environment for teaching technical writing that provides process-oriented collaborative writing supports and practices. This study also examined the effects of the system on EFL (English as a Foreign Language) students' collaborative writing experiences. In the experiment, a "process writing wizard" was created to guide students to complete an essay using comparison and contrast as the rhetorical form. The system provides step-by-step scaffolding guidance and allows multiple students to work synchronously on collaborative writing via Internet. To investigate the learning experiences of the students, five constructs—perceived ease of use, perceived usefulness, attitude to use, intention to use, and perceived response time from peers—were employed to examine if students feel comfortable in the multi-task, multi-user environments. The experimental results are encouraging in that they are consistent with the research propositions. The students also show positive continuing motivation to use the proposed system in future writing tasks. [ABSTRACT FROM AUTHOR]

Multicast based multi-party audio/video collaboration system is one important application for collaboration in internet. Adopting multicast could save bandwidth for group communication. But native multicast is not ubiquitously available which hurdles the application, on the other hand, the current multicast based A/V collaboration system lacks effective control and service. This paper introduces the controllable multiparty audio/video collaboration systems based on multicast over China Education and Research Network (CERNET). The native multicast environment and performance monitoring, control and management on audio/video collaboration, session management and congestion controls are presented. The controllable multi-party collaboration system has been implemented and applied on CERNET successfully. [ABSTRACT FROM AUTHOR]

In this paper we present a novel relevance feedback and latent semantic index based cultural relic image retrieval system. First, the optimum weights that can be used for iterative retrieval is computed , then a semantic image link network is constructed to store the semantic correlation information between images, which is obtained from memorized relevance feedbacks. Following image relevance feedback, Latent semantic indexing is applied to image retrieval, which helps saving in storage and estimating the hidden semantic relationship among images. To illustrate the potential of such an approach a prototype image retrieval system has been developed and Preliminary experimental results on a database containing about 2000 images demonstrate the effectiveness of the proposed model. [ABSTRACT FROM AUTHOR]

In this paper we implement the 3D virtual interactive snowboard game. It is not an on-line game but a bodily sensible game. We develop the terrain rendering engine which is designed for our interactive snowboard simulation game. It is developed by using real-time optimally adapting meshes (ROAM) for level-of-detail (LOD) rendering. The terrain engine also uses alpha blending for transition between level-of-details and collision between a character and the terrain is detected by ray-triangle intersection algorithm. The presented engine shows rapid response in rendering the terrain which is essential for an interactive snowboard simulation game. For a character's movement, physics engine is designed in which we define the two states called the Air and the Contact and classify four cases for the next position. HMD and motion tracker devices used in virtual reality applications are attached to our game engine so that users can experience the snowboard game in virtual space. It is expected from this experience that other sports games such as table-tennis, soccer, golf games and etc. can be easily implemented. [ABSTRACT FROM AUTHOR]

An advanced content-based news video browsing and retrieval system, NBR, is proposed in this work. The system is built on high-accuracy news story segmentation and topic caption text extraction. Its main features include category-based news story browsing, key-frame-based video abstract and keyword-based news story retrieval. In the paper, news story segmentation and topic caption text extraction, as well as content-based video browsing and retrieval, are addressed in detail. The system is helpful and effective for the overall understanding of the news video content. [ABSTRACT FROM AUTHOR]

Nowadays, most game story based on Western Myth and Cultures, this situation make the gamers bored. So some companies for game try to find something different stories for their game, and developing or developed the games based on Oriental Myth and Cultures. But the expression skills for this games, has the stories based on Oriental Myth and Cultures, using the realistic expression skills were used at other games. So I recommend the Oriental Painting Shader for games has the stories about Oriental Myth and Cultures. In this Paper, I optimized the Abridged Inside Effect of Oriental Painting Shader for 3D games, using the Sobel Edge Detecting for line drawing of oriental painting shader, and briefing about these algorithm. [ABSTRACT FROM AUTHOR]

Registering range images captured by 3D scanner and constructing a complete model of an object is frequently used in reverse engineering, computer game and animation, digital museum and digital heritage, etc. Many algorithms about registering the range images have been developed up to now. In this paper, a robust automated algorithm is presented based on surface characteristics extracting and matching techniques. The algorithm restores a set of point correspondences between every two adjacent range images without image position information or user interaction. Differential quantities are used as geometric descriptor and some other constraints are used to accelerate searching and matching processes and maintain result accuracy. After calculating the estimate of the rigid motion transformation between range images with selected point correspondences, a modified ICP algorithm is used to refine the result. The whole algorithm can be applied in many areas, especially in building the digital models of cultural artifacts and works of art. [ABSTRACT FROM AUTHOR]

An overlooked, yet essential problem in piano practice involves body posture. Bending the back, leaning towards the keys, lifting the wrist and other improper positions are usually noticed by piano teachers when instructing their students. If they sit too low, fingers will feel the burden of static arm weight; if they sit too high, the playing might become rigid with tension in wrist and shoulders. In this manner, visual feedback can help in realizing potential problems when playing the instrument. This paper discusses an innovative application of the techniques used for the 3D visualization of piano performances in any possible view, with the purpose of comparing them to a good model of someone playing the piano. It includes the capture and reconstruction of the 3D motion and posture of a professional piano player so that it may be compared against the posture and movements of students, by overlaying 2D videos of their practice session at the piano. [ABSTRACT FROM AUTHOR]

In some artificial systems, performing the realistic perception for actors which will handle both the processes to simulate the sensing organs and identify, will spend most computational time. Unfortunately, this matter even ruins the result of decision based on perception. In order to reduce the computation cost from a systemic view and optimize the performance of system, a brand-new coherent framework was proposed. The framework, which is a cycle of internal-state activizing desire, desire guiding perception, decision making based on perception, and the executing result feed backing to actor, mimics the principle that the behavior of the actor is excitated both by the internal motivation and external stimuli. Firstly, we modeled internal state of artificial actors, which caused by temporary stimuli and accumulation of physical and mental states. Secondly, the actors' desires were described which are generated by internal state and used for guiding perception. Thirdly, the net value of the possible features combinations for a given desire was figured out using decision-theoretic principles to determine whether the process on the features combinations is worthy or not. Then, a multi-objective decision making algorithm was introduced to achieve decision based on perception, thus the connection between the actual desires and behaviors are established. Finally, we validate the approach and algorithms in establishing an autonomous computer animation system by simulating the realistic behavior of fish in bio-system. [ABSTRACT FROM AUTHOR]

This paper addresses the problem of how to transform a photograph into Van Gogh's oil style painting. A novel line-integral convolution(LIC) based oil painting simulation framework is proposed. Several new technologies are proposed to improve the performance and artistic expressive power of our method. Firstly a new method named by streamlines filling is presented, and we modeled image as a cluster level lines which have minimal Euler's elastic energy, then we derived an evolution partial difference equation (PDE)to fill streamlines in image. Secondly we proposed a new method named by streamlines enhancing, a coherence-enhancing anisotropic diffusion is use to enhance the flow-like and close interrupted lines in the intensity image. Thirdly we propose a surface rendering algorithms combined diffuse and specular reflection with multiple light sources to simulate the oil painting's characteristics. Finally a better color fidelity between result image and the sample image of van Gogh style is achieved by color transfer algorithm. Experiments show that the performance of our proposed method is better than other similar LIC based rendering algorithms. [ABSTRACT FROM AUTHOR]

In this paper we present a novel feature-based texture design scheme using deformation techniques. Firstly, we apply a compass operator to extract the feature map from the input small sample texture. Secondly, we use the feature-guided patch searching algorithm to find satisfactory candidate patches taking both color errors and feature errors into account. When the new feature map is created, the designed texture is obtained simultaneously. Thirdly, a completion-based texture design method is employed to design a variety of large deformed textures. A designer can repeat the above steps to design satisfactory textures. The proposed algorithm has the ability to design a variety of versatile textures from a single small sample texture by measuring the structural similarity. Our experimental results demonstrate that our proposed technique can be used for other texture synthesis applications, such as Wang Tiles based cyclic texture design. [ABSTRACT FROM AUTHOR]

Content based image retrieval (CBIR) mostly uses color correlogram for image features because it extracts not only the color distribution of pixels in images like color histogram, but also extracts the spatial information of pixels in the images. The size of color correlogram depends on the number of quantized colors used for feature extractions. Usually, 64 quantized colors are used, and hence the size of the correlogram is 64x64 for unit distance. In this paper, we reduce the size of color correlogram to 9x9 by quantizing the color pixels using the median of pixels within a small 3x3 block. The proposed algorithm has smaller size of the correlogram and gives comparable image retrieval results. [ABSTRACT FROM AUTHOR]

Progressive data transmission is critical for implementing interactive walkthrough of large scale distributed virtual environments on Internet. This paper proposes an incremental AOI (Area of Interests) algorithm to determine dynamically which VRML objects should be downloaded while the viewpoint is moving in a VRML environment at each step. Our method has three major steps: (1) to divide the entire VRML ground uniformly into a rectangular mesh (m*n grids) along x-axis and y-axis respectively and store all the VRML objects overlapped by each grid into an adjacent list; (2) statically to determine all the grids overlapped by an AOI according to spatial coherence; (3) dynamically to determine newly visible and invisible grids overlapped by a moving AOI at each step, according to the temporal coherence between two consecutive AOI circles; (4) at each step, only newly overlapped VRML objects should be downloaded and rendered incrementally. Thus, the required VRML data downloads can be decreased dramatically at each moving step. Further, the proposed AOI algorithm is an integer incremental algorithm without multiplication, divisions and floating operations, and also it is suitable for hardware implementation. [ABSTRACT FROM AUTHOR]

In this paper, we presented a point sampled surface reconstruction method based on local geometry. First, an adaptive Binary Space Partition (aBSP) tree was built based on the local shape complexity which was judged by three factors: local main curvature, the normal cone and the number of points. Different local complexities produce different aBSP-trees. Then, each leaf node in the aBSP-tree was approximated by a weighted quadric function and the center points set of aBSP tree's leaf nodes could be treated as one approximation to the original point set at a given complexity of the local shape. Finally, a ray tracer based on point was used to render these aBSP-trees, which avoids triangulating of implicit surfaces before they are rendered. The experimental results show that the method can reconstruct sharp features very conveniently and effectively. [ABSTRACT FROM AUTHOR]

This paper proposes a sketch-based modeling and animation system. Most traditional modeling and animation systems require users to have professional techniques and outstanding 3D perception in order to perform precise adjustments on the rigid skeleton positions and angles for each key frame, which usually costs several hours to complete an animation. We here propose a modeling and animation system for non-expert users with only sketch interactions. In our system, we design a new soft curve skeleton to represent the model animation and deformation. By using this new curve skeleton, users can establish skeleton by sketch and design animation conveniently, and it will cost only several minutes to finish the animation task. Our system allows non-expert users to easily design and create non-precise models and animations. [ABSTRACT FROM AUTHOR]

This paper presents a new method for constructing parametric curve to interpolate a set of data points in plane. The constructed parametric curve has the precision of cubic polynomial function in the sense that if the given data points are taken from a cubic polynomial, then the constructed curve reproduces the cubic polynomial exactly. The comparisons of the precision of the new method with other ones are included. [ABSTRACT FROM AUTHOR]

Real-time deformation plays an important role in interactive applications such as video games. A new method of real-time dynamic deformation based on linear modal analysis is introduced in this paper. Compared to the existing techniques using the vertex program of the GPU to calculate vertex positions, our approach stores the modal displacement matrix in a series of 2D floating-point textures and the fragment program calculates vertex positions. We also encode the mesh neighbourhood information as an index form, and store it as textures. With a texture containing vertex positions, the fragment program can calculate vertex normals by local averaging. Experiments show that the proposed technique fully utilizes the parallel processing ability of the GPU, and it is suitable for the applications of real-time deformation. [ABSTRACT FROM AUTHOR]

In off-road simulation, the terrain is being modified as a result of its interaction with the vehicles. Previous methods dealing with tire tracks are to animate tire tracks and have no interactivity. In this paper, we describe a method to render tire tracks in dynamic terrain. In the base of hierarchical structure for terrain LOD, hierarchical structure starts at a resolution sufficient to represent the initial terrain, and then increases the resolution wherever necessary at the modified terrain regions. To avoid the cracks at the boundary between terrain cells, which are modified and increased the resolution, an algorithm based on window-scanning avoids cracks between neighboring cells in the 2×2 window is given. This algorithm avoids the transfer of cracks effectively through guaranteeing the results after window scanning will not impact the edges processed previously. The results of experiments show that not only this algorithm avoids crack effectively, but also the cost of computing is very low. [ABSTRACT FROM AUTHOR]

A novel algorithm and approach to kinematic inbetweening for motion animation is proposed. To represent motion of a character in computer animation, a parametric curve is used to specify motion path of character while a velocity profile curve describing the varied speed of character along the path. Given the motion path and speed, kinematic inbetweening technique is executed to generate motion inbetweens from which skeleton sequences for character animation are obtained by inverse kinematical technique. In this paper, the principle and a novel algorithm for kinematic inbetweening is proposed and several demonstrations provided. [ABSTRACT FROM AUTHOR]

To perform 3D animation with carving on surfaces of 3D models is a new branch of 3D modeling. A set of new methods are carried out in this paper. One based on recursion can solve the image transformation problem with curve constrain. The edge corroding method can gain a relatively external depth image from a 2D image. Also another based on partial resampling is used to paste a 2.5D model to any other 3D model, and has made some good results. The work of this paper has greatly shortened the path from 2D editing to 3D surface animation. [ABSTRACT FROM AUTHOR]

The paper present a novel watermarking algorithm, which is obtained based on a watershed segmentation, one image watermarking algorithm and the addition property of Fourier transform. Firstly, some feature points of 3D meshes are extracted by using an effective watershed segmentation algorithm. Furthermore, in order to keep the mesh transparency, watermark information is preprocessed by using an image watermarking algorithm. Finally, digital watermarking is embedded into those feature points. During extraction, the target model is registered by principal component analysis. We have applied our method to a number of 3D mesh models of different geometric and topological complexity. Those experimental results prove that the algorithm is robust against a variety of attacks, such as rotation, translation, scaling, combinations of the above and re-sort. [ABSTRACT FROM AUTHOR]

In order to decrease the data volume of 3D textured models in digital museum with significant features preservation, a new simplification method for texture-mesh based on triangle collapse is presented. By introducing the concepts of geometry and texture boundary, the quadric error matrices are improved, and constraint strategies are adopted to retain the feature of geometry boundaries and texture attributes during the simplification process. In addition, a method combining octree-based compression with progressive mesh is given to provide a continuous multi-resolution representation of 3D models. The proposed methods have been successfully applied to progressive transmission and representation system of 3D models in digital museums. [ABSTRACT FROM AUTHOR]

An algorithm is presented to construct a C2-continuous B-spline quaternion curve which interpolates a given sequence of unit quaternions on the rotation group SO(3). We present a method to extend a B-spline interpolation curve to SO(3). The problem is essentially to find the quaternion control points of the quaternion B-spline interpolation curve. Although the associated constraint equation is non-linear, we can get the accurate quaternion control points according to two additional rules for quaternion computations in S3. In addition, we provide a point insertion method to construct interpolation curves that have local modification property. The effectiveness of the algorithm is verified by applying it to some examples. [ABSTRACT FROM AUTHOR]

Modern graphics application systems have to render many 3D triangle mesh models, thereby facing problems of memory and bandwidth. A general significant solution is to compress the static 3D triangle mesh model at the preprocessing phase, especially the topological information. This paper presents a new triangle meshes compression algorithm, which encodes connectivity information between vertex chains in the meshes that are already stripified. The proposed algorithm provides a new representation that is guaranteed to encode any stripified meshes in less than 1.67 bits/T, and 1.05 bits/T on average. Furthermore, the proposed algorithm employs a short compression/decompression time. Hence it will satisfy real-time rendering constraints. [ABSTRACT FROM AUTHOR]

In this paper, we present an animation technique based on muscle forces, inverse dynamics and a parameter optimization. We do a crude motion planning in terms of accelerations. By integrating the accelerations given an initial configuration, we obtain all essential kinematic data. We evaluate the quality of motion planning by using various constraints and a performance index evaluated using inverse dynamics. The best motion can be chosen by using a parameter optimization method. The human motion is so complicated that it needs the motions to be coordinated nicely. The planned motion is checked using a criterion which we call the footprint function: ground reaction forces if the body is on the ground, acceleration of the body center as well as energy if it is in the air. In the motion planning for a body in the air, we reduce control variables so that we work with a smaller search space with only feasible motions. Then we include human skeletal and muscle geometry in the footprint function so that we can convert robotic rotary actuators to muscles using static optimization: given a set of joint torques, we distribute them to the eight sets of human low extremity muscles. We search most human-like animated motion from an infinite set of possible motions. We compare these with experimental data. Futhermore, the muscle geometric data obtained from our linear actuator modeling can be used in tissue animation. [ABSTRACT FROM AUTHOR]

With the development of network, it's a common requirement to perceptually access the 3D scenes at a remote server. This demand has not been filled by software standards and their implementations, leaving a wide potential for technical innovations. In the paper, we present a QoS (Quality of Service) controller for remote rendering of 3D contents, aiming at higher real-time performance just as rendering local 3D scenes. The model of our QoS controller is defined by a high-level heuristic function, which has integrated important perceptual factors. And then, guided by the QoS controller, a hybrid transcoding algorithm is developed, which adaptively partitions each 3D model into different modality: the metadata (its compressed base mesh with texture) and a series of refiner meshes. Consequently, the 3D scenes can be adaptively and progressively transmitted to a requesting client, and be fluently displayed at end user's window in a constant frame rate. Experimental results show the soundness of the proposed controller and algorithm guided by the 3D controller. [ABSTRACT FROM AUTHOR]

This paper presents a novel approach for view-dependent streaming of highly detailed and irregular meshes. In contrast to the con- ventional progressive streaming where the resolution of a model changes in the geometry space, our server firstly maps the 3D surfaces onto the parameter space in which the geometry images (GIM) and normal map atlas are obtained by regular re-sampling. By constructing the regular quadtree-based hierarchical representation based on GIM, we accomplish an efficient compression scheme to encode the hierarchical structure that minimize the network communication overhead to facilitate real time mesh update in the large-scale model visualization from clients. Further- more, the encoded nodes can be transmitted in arbitrary order, so the extreme flexibility in transmission could be achieved. In particular, by using normal texture atlas, the rendering result of a partially transmitted model is improved greatly, therefore only the geometry on the silhouette to the current viewpoint requires to be refined and transmitted, which can minimize the amount of data needed to transfer each frame. Experimental results indicate that our approach is efficient enough for a broadcast scenario where one server streams the multiresolution GIM data to multiple clients with different viewpoints. [ABSTRACT FROM AUTHOR]

This study aims to explore two crucial aspects of collaborative work and learning: the importance of enabling CSCL applications, on the one hand, to capture and structure the information generated by group activity and, on the other hand, to extract the relevant knowledge in order to provide learners and tutors with efficient awareness and support as regards collaboration. To this end, we first identify and define the main types of information generated in on-line group activity and then propose a process for efficiently embedding this information and the knowledge extracted from it into CSCL applications for awareness and feedback purposes. The conceptual model proposed finally gave rise to the design and implementation of a CSCL generic platform, called the Collaborative Learning Purpose Library (CLPL), which serves as a basis for the systematic development of collaborative learning applications and for providing full support to the mentioned process of knowledge management. [ABSTRACT FROM AUTHOR]

To meet the needs of education in the learning community, an improved adaptive filtering algorithm for teaching resources based on vector space model was proposed in the paper. First, feature selection and pseudo feedback were used to select the initial filtering profiles and thresholds through training algorithm. Then user feedback was utilized to modify the profiles and thresholds adaptively through filtering algorithm. The algorithm had two advantages, the first was that it could carry on self-study to improve the precision; the second was that the execution did not need massive initial texts in the process of filtering. The algorithm was also used in personalized Recommendation service system based on Community E-learning. The result manifested that the algorithm was effective. [ABSTRACT FROM AUTHOR]

Edutainment is a promising approach to motivating students to learn, that is, making learning fun. This paper describes a real world edutainment system that makes learning fun using ubiquitous computing technology. We focus on human-human interaction in the real world as a new approach to edutainment in the next generation. Human actors can teach interactively and flexibly in various ways, by considering players' (students') characteristics and the environmental conditions. Involvement of human actors as active characters of a game story in edutainment is an advantage that conventional edutainment does not currently have. [ABSTRACT FROM AUTHOR]

storytelling by a child, as an educational activity, influences significantly the child's linguistic ability, thought process, imagination, and creativity. There presently exist many software-based storytelling applications. However, most are deemed not suitable to Chinese children due to various cultural and language barriers. In this paper, combining the characteristics of Chinese children and using the multimodal interaction pattern based on speech and pen-gesture, we present a 3D storytelling system for children. The usability of two versions of the storytelling system is evaluated. Evaluation results suggest version 2 of the system to be of higher usability, as are comments on revising the software. [ABSTRACT FROM AUTHOR]