206756450
Nonlinear Dimensionality Reduction by Locally Linear Inlaying
High-dimensional data is involved in many fields of information processing. However, sometimes, the intrinsic structures of these data can be described by a few degrees of freedom. To discover these degrees of freedom or the low-dimensional nonlinear manifold underlying a high-dimensional space, many manifold learning algorithms have been proposed. Here we describe a novel algorithm, locally linear inlaying (LLI), which combines simple geometric intuitions and rigorously established optimality to compute the global embedding of a nonlinear manifold. Using a divide-and-conquer strategy, LLI gains some advantages in itself. First, its time complexity is linear in the number of data points, and hence LLI can be implemented efficiently. Second, LLI overcomes problems caused by the nonuniform sample distribution. Third, unlike existing algorithms such as isometric feature mapping (Isomap), local tangent space alignment (LTSA), and locally linear coordination (LLC), LLI is robust to noise. In addition, to evaluate the embedding results quantitatively, two criteria based on information theory and Kolmogorov complexity theory, respectively, are proposed. Furthermore, we demonstrated the efficiency and effectiveness of our proposal by synthetic and real-world data sets.
59116191
A High Accuracy Printed Traditional and Simplified Chinese Character Document Recognition System
15567192
Application of virtual reality in volumetric cellular visualization
Recent advancement in high-resolution confocal imaging has provided valuable novel insights into structural relationships within cells and tissues in vitro and in vivo. Development in volume rendering technique enables visualization of 3D dataset in real-time. Here, we present a system in which 3D models are reconstructed from the stacked 2D images obtained with a confocal microscope, and subsequently visualized using volume rendering technique. Using the reconstructed 3D model, we apply virtual reality method to provide an intuitive way to view and manipulate the 3D cellular environment.
15260068
Motion-compensating long-term memory prediction
Motion-compensating long-term memory prediction extends the spatial displacement utilized in block-based hybrid video coding by a variable time delay permitting the use of more frames than the previously decoded one for motion compensation. The long-term memory covers the decoded frames of some seconds at encoder and decoder. We investigate the influence of memory size in our motion compensation scheme and analyze the trade-off between the bit-rates spent for motion compensated prediction and residual coding. Simulation results are obtained by integrating long-term memory prediction into an H.263 codec. PSNR improvements up to 2 dB for the Foreman sequence and 1.5 dB for the Mother-Daughter sequence are demonstrated in comparison to the TMN-2.0 H.263 coder.
9412909
Some issues in a functional implementation of a finite element algorithm
We describe our experience of implementing a finite element algorithm for simulating fluid dynamics using Haakell. The main emphasis ia on issues arising from implementing a direct method and an iterative method for solving sparse matrix systems that arise in applying the finite element method. For the direct method, it is demonstrated that a Quadtree data structure, described by Wise and Wainwright et al. [1, 2], is generally fester than other list baaed data structures. Aleo it ia not very sensitive to the sparsity structure. For the iterative method, we look at a complex assembly process and compare two coding schemes. The usual procedural algorithm is, as might be expected, not the best in a functional implementation. We also discuss our experience in coding these algorithms.
28013231
Global stabilization of a class of time-delay nonlinear systems
This paper is concerned with the problem of global stabilization by state feedback and output feedback for a class of time-delay nonlinear systems that are dominated by a triangular system satisfying linear growth conditions. By solving the Lyapunov equation and constructing the appropriate Lyapunov-Krasovskii functionals (LKF), the linear and memoryless state feedback controller and output feedback controller making the closed-loop system globally asymptotically stable (GAS) are explicitly constructed respectively. Comparing our design scheme with the backstepping method which has been widely used to deal with strictly feedback nonlinear systems, our design scheme is much simpler and more efficient. An example is given to show that the proposed design procedures are very simple and efficient.
18699103
Experiences of Parallelising Finite-element Problems in a Functional Style
Experiences are described of parallelizing a functional finite-element program (written in Haskell) for the solution of computational fluid-dynamics problems. A transformation prototyping approach using a system developed at the University of York, which simulates idealised parallel machines on a conventional sequential workstation, is presented. In this paper we demonstrate: (a) the relative simplicity of the functional approach for parallelizing a complex program compared with the conventional procedural approach; (b) the suitability of functional languages for prototyping parallel algorithms to improve an implementation; and (c) the considerable assistance provided by the simulator.