Jiayi Xu

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Providing interactive control is a hot topic in crowd-navigation research. Here, the authors propose a simple but effective way for authoring a crowd scene. With their governing tool, users can easily drive the flow of crowds by sketching velocities on anchor points in the scene. This approach is fast enough to allow on-the-fly modification of vector fields.
In this article, we adopt Jin et al.'s GPU-based method to solve the Navier-Stokes equations and model the fluid evolution of the patterning process. Based on this method, we add more flexible dye injection operations and more locally controllable pattern design tools. We based our nondissipative solver on semi-Lagrangian methodology, which eliminates the(More)
We propose a novel shape-constrained flock animation system for interactively controlling flock navigation in virtual environments. This system is capable of making the spatial distribution of a flock meet static or deforming shape constraints while performing flock simulation. Such a capability can find many applications in the entertainment industry.(More)
Understanding co-occurrence in urban human mobility (i.e. people from two regions visit an urban place during the same time span) is of great value in a variety of applications, such as urban planning, business intelligence, social behavior analysis, as well as containing contagious diseases. In recent years, the widespread use of mobile phones brings an(More)
Interactive control is one of the key issues when simulating crowd navigation in virtual environment. In this paper, we propose a simple but practical method for authoring crowd scenes in an effective and intuitive way. Radial Basis Functions (RBF) based vector field is employed as the governing tool to drive the motion flow. With this basic mathematical(More)
Support vector machines (SVMs) are supervised learning models traditionally employed for classification and regression analysis. In classification analysis, a set of training data is chosen, and each instance in the training data is assigned a categorical class. An SVM then constructs a model based on a separating plane that maximizes the margin between(More)
Two new lasiodiplodins (1-2) together with three known analogues, were isolated from a mangrove endophytic fungus, Lasiodiplodia sp. 318#. Their structures were established by spectroscopic techniques (1D- and 2D-NMR, HR-ESI-MS, etc.), and electronic circular dichroism. Cytotoxic activities of compounds 1-5 were evaluated in vitro. Compound 4 was the most(More)
This work addresses the rate-distortion (R-D) optimal packetization (OP) of embedded bitstreams into independent source packets, in order to limit error propagation in transmission over packet lossy channels. The input embedded stream is assumed to be an interleaving of $K$ independently decodable basic streams. To form $N$ independent source packets, each(More)