作者：
A. KoschanSunHo LeeM.A. AbidiImaging
Robotics and Intelligent Systems Laboratory Department of Electrical and Computer Engineering University of Tennessee USA
A new method is presented for the localization and recognition of three-dimensional objects using color information. In the first processing step, we estimate depth information by either applying a chromatic block mat...
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A new method is presented for the localization and recognition of three-dimensional objects using color information. In the first processing step, we estimate depth information by either applying a chromatic block matching method to color stereo images or acquiring a range image from a laser scanner. Second, the computed depth maps are segmented to distinguish between the image background and the objects that should be recognized. Assuming that the segmented regions represent single objects in the three-dimensional scene, feature vectors are generated based on color histograms. The Euclidean distance is used as well as the scalar product to measure the similarity between the feature vectors computed from the color image and the feature vectors stored in a database.
One of the primary tasks in the area of uniform dependence loops, is predicting the execution propagation, as well as finding an optimal time schedule. In this work, the problem of scheduling using wavefront predictio...
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ISBN:
(纸本)0769511538
One of the primary tasks in the area of uniform dependence loops, is predicting the execution propagation, as well as finding an optimal time schedule. In this work, the problem of scheduling using wavefront prediction is presented. The geometric concepts of time instance subspaces and execution pattern are introduced. A quite simple and low complexity scheduling algorithm is presented. The index space is split into geometric subspaces and any point can be located in them. Each point is then scheduled according to the subspace where it belongs.
This paper proposes a new method for the problem of minimizing the execution time of nested for-loops using a tiling transformation. In our approach, we are interested not only in tile size and shape according to the ...
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ISBN:
(纸本)0769509908
This paper proposes a new method for the problem of minimizing the execution time of nested for-loops using a tiling transformation. In our approach, we are interested not only in tile size and shape according to the required communication to computation ratio, but also in overall completion time. We select a time hyperplane to execute different tiles much more efficiently by exploiting the inherent overlapping between communication and computation phases among successive, atomic tile executions. We assign tiles to processors according to the tile space boundaries thus considering the iteration space bounds. Our schedule considerably reduces overall completion time under the assumption that some part from every communication phase can be efficiently overlapped with atomic, pure tile computations. The overall schedule resembles a pipelined datapath where computations are not anymore interleaved with sends and receives to non-local processors. Experimental results in a cluster of Pentiums by using various MPI send primitives show that the total completion time is significantly reduced.
This paper proposes the use of fuzzy modeling algorithms to analyze gene expression data. Current algorithms apply all potential combinations of genes to a fuzzy model of gene interaction (for example, activator/inhib...
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ISBN:
(纸本)0780370449
This paper proposes the use of fuzzy modeling algorithms to analyze gene expression data. Current algorithms apply all potential combinations of genes to a fuzzy model of gene interaction (for example, activator/inhibitor/target) and are evaluated on the basis of how well they fit the model. However, the algorithm is computationally intensive; the activator/inhibitor model has an algorithmic complexity of O(N/sup 3/), while more complex models (multiple activators/inhibitors) have even higher complexities. As a result, the algorithm takes a significant amount of time to analyze an entire genome. The purpose of this paper is to propose the use of clustering as a preprocessing method to reduce the total number of gene combinations analyzed. By first analyzing how well cluster centers fit the model, the algorithm can ignore combinations of genes that are unlikely to fit. This will allow the algorithm to run in a shorter amount of time with minimal effect on the results.
We propose a new channel allocation scheme for improving the quality of service in cellular mobile networks. The proposed algorithm prioritizes handoff call requests over new call requests. The goal is to reduce the h...
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We propose a new channel allocation scheme for improving the quality of service in cellular mobile networks. The proposed algorithm prioritizes handoff call requests over new call requests. The goal is to reduce the handoff failures while still making efficient use of the network resources. A performance measure is formed as a weighted linear function of new call and handoff call blocking probabilities. This problem is formulated as a semi-Markov decision process with an average cost criterion. A simulation-based learning algorithm is then developed to approximate the optimal control policy online using the generated samples from direct interactions with the network. It is based on an approximate model that is estimated simultaneously while learning a control policy. The estimated model is used to direct the search for an optimum policy. Extensive simulations are provided to assess the effectiveness of the algorithm under a variety of traffic conditions. Comparisons with some well-known allocation policies are also presented. Simulation results show that for the traffic conditions considered in this paper, the proposed scheme has a comparable performance to the optimal guard channel approach.
As a coding technique designed for use with multiple transmit antennas, space-time coding (STC) has been gaining more and more attention recently due to its attractive characteristics. One of these characteristics is ...
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As a coding technique designed for use with multiple transmit antennas, space-time coding (STC) has been gaining more and more attention recently due to its attractive characteristics. One of these characteristics is to provide diversity at the receiver and coding gain over an uncoded system without sacrificing bandwidth. It is also attractive because it increases the effective transmission rate as well as the potential system capacity. This paper presents powerful and computationally efficient linear and decision feedback equalization schemes, considering both zero-forcing (ZF) and minimum mean-square error (MMSE) criteria to combat intersymbol interference (ISI) and obtain diversity gain in a system with a transmit diversity technique using symbol-level space-time block coding. General linear and decision feedback equalizers are derived for the transmit diversity case with two transmit antennas and M receive antennas. The conditions are investigated under which FIR channels can be equalized perfectly using linear FIR filters in noise-free environments. BPSK modulation scheme is assumed to simulate the proposed diversity and equalization methods. Numerical results show significant performance improvements compared to the cases without equalization.
As an effective technique to combat adverse effects of fading, provide diversity and increase the transmission rate, space-time coding (STC) has been gaining more and more attention. This paper presents efficient zero...
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As an effective technique to combat adverse effects of fading, provide diversity and increase the transmission rate, space-time coding (STC) has been gaining more and more attention. This paper presents efficient zero-forcing (ZF) and minimum mean-square error (MMSE) equalization schemes to combat intersymbol interference (ISI) and obtain diversity gain in a system using symbol-level space-time block coding. General linear and decision feedback equalizers are derived with two transmit antennas and M receive antennas. The conditions are explored under which FIR channels can be equalized perfectly in noise-free environments. In order to estimate the system performance, upper bounds of bit error rate (BER) are derived. A training-aided method are proposed as well to estimate the channel state information (CSI) utilizing training sequences. Numerical results of the proposed techniques show significant performance improvement compared to the case without equalization, and show the tightness of the upper bounds along with the effectiveness of the channel estimation scheme.
The ability to autonomously generate and execute large angle attitude maneuvers, while operating under a number of celestial and dynamical constraints, is a key factor in the development of several future space platfo...
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Multimedia applications are fast becoming one of the dominating workloads for modern computersystems. Since these applications normally have large data sets and little data-reuse, many researchers believe that they h...
ISBN:
(纸本)9781581133349
Multimedia applications are fast becoming one of the dominating workloads for modern computersystems. Since these applications normally have large data sets and little data-reuse, many researchers believe that they have poor memory behavior compared to traditional programs, and that current cache architectures cannot handle them well. It is therefore important to quantitatively characterize the memory behavior of these applications in order to provide insights for future design and research of memory systems. However, very few results on this topic have been published. This paper presents a comprehensive research on the memory requirements of a group of programs that are representative of multimedia applications. These programs include a subset of the popular MediaBench suite and several large multimedia programs running on the Linux, Windows NT and Tru UNIX operating systems. We performed extensive measurement and trace-driven simulation experiments. We then compared the memory utilization of these programs to that of SPECint95 applications. We found that multimedia applications actually have better memory behavior than SPECint95 programs. The high cache hit rates of multimedia applications can be contributed to the following three factors. Most multimedia applications apply block partitioning algorithms to the input data, and work on small blocks of data that easily fit into the cache. Secondly, within these blocks, there is significant data reuse as well as spatial locality. The third reason is that a large number of references generated by multimedia applications are to their internal data structures, which are relatively small and can also easily fit into reasonably-sized caches.
The paper presents a number of image processing and pattern recognition applications using coordinate logic filters which execute coordinate logic operations among the pixels of the image. These filters are very effic...
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ISBN:
(纸本)9539676940
The paper presents a number of image processing and pattern recognition applications using coordinate logic filters which execute coordinate logic operations among the pixels of the image. These filters are very efficient in various 1D, 2D or higher-dimensional digital signal processing applications, such as noise removal, magnification, opening, closing, skeletonization, coding, edge detection, feature extraction, and fractal modeling. The key issue in the coordinate logic analysis of images is the method of fast successive filtering and managing of the residues. The desired processing is achieved by executing only direct logic operations among the pixels of the given image. Coordinate logic filters can be easily and quickly implemented using logic circuits or cellular automata; this is their primary advantage.
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