195837988
An optimal algorithm for floorplan area optimization
An optimal algorithm for the VLSI floorplan area optimization problem is presented. The algorithm is an extension of the technique described by L. Stockmeyer (Information and Control, vol.59, p.91-101, 1983). Experimental results indicate that this algorithm pruned a very large number of redundant implementations. In addition, since the algorithm basically exploits the geometric property of the topology of the given floorplan it does not need to depend on the polar dual graphs to calculate the longest paths. Consequently it is able to run more efficiently than the branch-and-bound algorithm.<<ETX>>
18451647
Optimal circuit clustering for delay minimization under a more general delay model
This paper considers the area-constrained clustering of combinational circuits for delay minimization under a more general delay model, which practically takes variable interconnect delay into account. Our delay model is particularly applicable when allowing the back-annotation of actual delay information to drive the clustering process. We present a vertex grouping technique and integrate it with the algorithm (Rajaraman and Wong, 1995) such that our algorithm can be proved to solve the problem optimally in polynomial time.
45880739
Optimal circuit clustering with variable interconnect delay
The paper aims at extending the circuit clustering algorithm of Rajaraman and Wong (1995) to handle a more sophisticated delay model, which practically takes variable interconnect delay into account. Our delay model is particularly applicable in allowing the back-annotation of actual delay information to drive the clustering process. We first show that the original algorithm fails to produce optimal solutions for this delay model. In order to solve the problem, a generalized algorithm based on an extension of Rajaraman and Wong is proposed such that the problem can be solved optimally while the polynomial time complexity is maintained.
47136995
Routing for symmetric FPGAs and FPICs
A new class of routing structures with fixed orthogonal wire segments and field programmable switches at the intersections of the wire segments is proposed. In comparison with the conventional two-dimensional field-programmable gate array (FPGA) routing structure, this class of routing structures has the advantage of using a smaller number of active programmable switches. An existing field-programmable interconnect chip (FPIC) routing structure can be included as a special case in our class of routing structures. Using a probabilistic model, we prove that complete routing can be achieved with a high degree of probability in a routing structure of this class in which the number of tracks in each channel approaches the lower bound asymptotically. We present a sequential routing algorithm based on the solution of the single net routing problem. We take into account the delay introduced by the active programmable switches on a routing path and formulate the single net routing problem as a node-weighted Steiner minimum tree (NWSMT) problem in a bipartite graph G. Since our single net routing problem is NP-complete, a polynomial time approximate algorithm is proposed. We prove that our single net routing algorithm produces an optimal solution for some special classes of bipartite graphs. In general, the solution obtained by our algorithm bas a performance bound of min{/spl Delta/(V/Z), |Z|-1}. Experimental results for several industrial circuits show a reduction of up to 41% in the number of active programmable switches when compared with corresponding results for the conventional FPGA routing structure.
2339232
Maze routing with OPC consideration
13299166
An Interpolated Volume Model for Databases
In this paper we present a volume data model amenable to querying volumes in databases. Unlike most existing volume models, which are directed towards specific applications (notably, volume displaying) and are therefore directed towards executing with the greatest possible efficiency a small set of operations, we are interested in defining a volume algebra through which generic query conditions can be composed.
33719933
Possibilistic C-Template Clustering and Its Application in Object Detection in Images
We present in this paper a new type of alternating-optimization based possibilistic c-shell clustering algorithm called possibilistic c-template (PCT). A template is represented by a set of line segments. A cluster prototype consists of a copy of the template after translation, scaling, and rotation transforms. This extends the capability of shell clustering beyond a few standard geometrical shapes that have been studied so far. We use a number of 2-dimensional data sets to illustrate the application of our algorithm in detecting generic template-based shapes in images. Techniques taken to relax the requirements of known number of clusters and good initialization are also described. Results for both synthetic and actual image data are presented.
15147164
Balanced incomplete designs for 3D perceptual quality estimation
Many factors, such as the number of vertices and the resolution of texture, can affect the display quality of 3D objects. When the resources of a graphics system are not sufficient to render the ideal image, degradation is inevitable. It is therefore important to study how individual factors affect the overall quality, and how the degradation can be controlled given limited resources. The essential factors determining the display quality are reviewed and a 3D perceptual estimation method is described. One of the major concerns in designing perceptual experiments is the large number of evaluations to be performed by judges, which results in fatigue and errors in judgement. To reduce judging fatigue and increase reliability of evaluations we propose using a statistical approach, following the design of experiments technique of balanced incomplete block design (BIBD). We develop models following BIBD for perceptual experiments and validate our model with experimental results. Even though the BIBD framework for perceptual evaluations is described in the context of 3D quality estimation, the approach can be used in other perceptual evaluation scenarios as well.
566237
Regularized discriminant analysis for high dimensional, low sample size data
Linear and Quadratic Discriminant Analysis have been used widely in many areas of data mining, machine learning, and bioinformatics. Friedman proposed a compromise between Linear and Quadratic Discriminant Analysis, called Regularized Discriminant Analysis (RDA), which has been shown to be more flexible in dealing with various class distributions. RDA applies the regularization techniques by employing two regularization parameters, which are chosen to jointly maximize the classification performance. The optimal pair of parameters is commonly estimated via cross-validation from a set of candidate pairs. It is computationally prohibitive for high dimensional data, especially when the candidate set is large, which limits the applications of RDA to low dimensional data.In this paper, a novel algorithm for RDA is presented for high dimensional data. It can estimate the optimal regularization parameters from a large set of parameter candidates efficiently. Experiments on a variety of datasets confirm the claimed theoretical estimate of the efficiency, and also show that, for a properly chosen pair of regularization parameters, RDA performs favorably in classification, in comparison with other existing classification methods.
206985371
Framework and network based multimedia object management environment
Because multimedia objects are becoming more prevalent, on ever increasing volume, inventing an efficient multimedia object management environment is a matter of increasing urgency. In recognition of this crisis, we developed the multimedia object management environment (MOME) that includes a suite of tools such as the Vortex framework, and network file indexer (NFI). MOME also includes a fully featured graphical user interface for maximum user control and flexibility. With meta data, it automatically generates indexes and paths for different types of multimedia objects and allows users to quickly find what they are looking for. In this paper, we address the background, architecture, and performance of MOME in detail.