Young-Min Kang

Processing a reachability query in large-scale networks using existing methods remains one of the most challenging problems in graph mining. In this paper, we propose a novel incremental algorithmic framework for arbitrary-order reachability computation in massive graphs. The proposed method is intuitive and significantly outperforms the currently known methods in terms of computation time. We focus on the arbitrary-order reachability matrix framework called AORM, which can handle directed and disconnected networks such as citation networks. The AORM can handle diverse types of real-world datasets. We conduct extensive experimental studies with twenty synthetic networks generated from five random graph generation models and twenty massive real-world networks. The experimental results show the advantages of the method in terms of both computational efficiency and approximation controllability. In particular, the proposed method outperforms up to 10 times compared to NetworkX for incremental all-pairs shortest paths computation. Moreover, the computational results of the method rapidly converge to the ground truths. Thus, we can get the correct solution in the early stage of the incremental approximation. We can employ the method as a versatile feature extraction framework for network embedding. Overall, the experimental results present a remarkable improvement in speed-up for reachability computation.

In this paper, we propose an efficient and stable animation and rendering method for complex mass‐spring‐based cloth model for interactive applications. Although the mass‐spring model can be easily constructed and simulated, it is well known that the model suffers from the instability problem. The method proposed in this paper employs the harmonic oscillation model and analytically integrates the force for better stability and accuracy while keeping the integration scheme still explicit. As the integration scheme is explicit, the method can be easily parallelized, and the performance improvement can be easily obtained by exploiting the parallelism in the graphics processing unit. For the realistic representation of virtual clothes, we also proposed an efficient and effective rendering method for woven surfaces on the basis of alternating anisotropic reflectance and microfacet distribution function rotation. Copyright © 2012 John Wiley & Sons, Ltd.

We present a new procedural method for photorealistic rendering of woven fabric material. The goal of our research is to provide a new procedural method that renders photorealistic woven fabric without any measured data. The proposed method models the reflectance properties of woven fabric with alternating anisotropy and yarn-level surface normal manipulation. The proposed method models the reflectance properties of woven fabric with alternating anisotropy and deformed microfacet distribution function (MDF). The deformed MDF effectively represents the perturbed reflectance caused by bumps on the woven fabric surface. The experimental results show the proposed method can be successfully applied to photorealistic rendering of diverse woven fabric materials.

We present an efficient method for rapid animation of mass-spring model with a large number of mass-points. Realistic cloth simulation requires large amount of time in general. This is not only because the calculation for one step requires much time but also because the cloth simulation easily tends to become unstable. Although the implicit method can make the simulation stable, it is still impossible to generate interactive animation when the number of mass-points is sufficiently large enough to represent realistic wrinkles. An efficient animation method proposed by M. Desbrun (1999) also involves O(n/sup 2/)-sized matrix so that it cannot be applied to models with a large number of mass-points. A stable approximate method without matrix operations has been introduced by M. Oshita and A. Makinouchi (2001), but its physical correctness is significantly impaired as the stiffness increases or the timestep becomes large. In this paper we propose a bilayered approach for efficient cloth animation with a large number of mass-points. The proposed method uses two mass-spring meshes. One of them is a rough mesh for representing global motion, and the other is a fine mesh for realistic wrinkles. The experimental results show that the method can be successfully used for real-time animation of plausible cloth models.