7801331
FPGA implementation of digital filters synthesized using the frequency-response masking technique
The effective length of a filter designed using the frequency-response masking technique is very high and requires a very large number of delay elements. In this paper, we present some useful techniques for reducing the data transfer between the FPGA and external memory when the random logic are implemented using FPGA and the delay elements are implemented using external memory such as DRAM.
2854649
Frequency-response-masking technique incorporating extrapolated impulse response band-edge shaping filter
Techniques based on the frequency-response masking (FRM) approach are known to be highly efficient for achieving drastic reduction of the number of multipliers and adders in narrow transition band linear-phase finite-impulse response (FIR) filters. Basic FRM structure comprises a band-edge shaping filter and two masking filters. It is observed that the impulse response of the band-edge shaping filter of FRM shows quasi-periodic property. Previous study demonstrated that the quasi-periodic property of the impulse responses of lowpass or highpass digital FIR filters can be exploited to reduce the complexity of the filter by using extrapolated impulse response technique. Extrapolating the idea, the band-edge shaping filter in FRM may be designed by the extrapolated impulse response technique. In this paper, an FRM technique incorporating extrapolated impulse response band-edge shaping filter is introduced. An iterative optimization procedure is proposed to design the FRM subfilters. An example taken from the literature is used to illustrate that the number of multipliers produced by our technique is less than 80 percent of earlier results.
17955850
Signed power-of-two allocation scheme for the design of lattice orthogonal filter banks
In signed power-of-two (SPT) coefficient digital filter design, it is well known that a better frequency response performance can be achieved if the number of SPT terms for each coefficient is not limited to a fixed number but instead, is allowed to vary subject to a given number of total SPT terms for the filter. Many SPT term allocation schemes have been developed for distributing the number of SPT terms to the coefficients. In this paper, an SPT term allocation scheme is developed for the design of lattice orthogonal filter banks. The SPT terms are allocated to coefficients one at a time to minimize the frequency response errors due to rounding the coefficients to SPT numbers. Examples show that the proposed allocation scheme is eminently suitable for the design of SPT coefficient lattice filter banks. It is superior to those reported in the literature.
5687277
A self-adaptive scheduling algorithm of on-demand broadcasts
In mobile wireless systems data on air can be accessed by a large number of mobile users. Many of these applications such as wireless internets and traffic information systems are pull-based, that is, they respond to on-demand user requests. In this paper, we study the scheduling problems of on-demand broadcast environments. Traditionally, the response time of the requests has been used as a performance measure. In this paper we consider the performance as the average cost of request composed of three kinds of costs—access time cost, tuning time cost, and cost of handling failure request. Our main contribution is a self-adaptive scheduling algorithm named LDFC, which computes the delay cost of data item as the priority for broadcast. It performs well compared with some previous algorithms in this context.
11507388
JPT: A Java Parallelization Tool
PVM is a succesfull programming environment for distributed computing in the languages C and Fortran. Recently several implementations of PVM for Java have been added, making PVM programming accessible to the Java community. 
 
With PVM for Java however, the user still needs to partition the problem, calculate the data partitioning and program the message passing and synchronization. In this paper, JPT is introduced, a parallelization tool which generates PVM code from a serial Java program. JPT automatically detects parallel loops and generates master and slave PVM programs.
8460642
Recovering photometric properties of architectural scenes from photographs
In this paper, we present a new approach to producing photorealistic computer renderings of real architectural scenes under novel lighting conditions, such as at different times of day, starting from a small set of photographs of the real scene. Traditional texture mapping approaches to image-based modeling and rendering are unable to do this because texture maps are the product of the interaction between lighting and surface reflectance and one cannot deal with novel lighting without dissecting their respective contributions. To obtain this decomposition into lighting and reflectance, our basic approach is to solve a series of optimization problems to find the parameters of appropriate lighting and reflectance models that best explain the measured values in the various photographs of the scene. The lighting models include the radiance distributions from the sun and the sky, as well as the landscape to consider the effect of secondary illumination from the environment. The reflectance models are for the surfaces of the architecture. Photographs are taken for the sun, the sky, the landscape, as well as the architecture at a few different times of day to collect enough data for recovering the various lighting and reflectance models. We can predict novel illumination conditions with the recovered lighting models and use these together with the recovered reflectance values to produce renderings of the scene. Our results show that our goal of generating photorealistic renderings of real architectural scenes under novel lighting conditions has been achieved. CR Categories: I.2.10 [Artificial Intelligence]: Vision and Scene Understanding—modeling and recovery of physical attributes I.3.7 [Computer Graphics]: Three-dimensional Graphics and Realism—color, shading, shadowing, and texture , visible line/surface algorithms I.4.8 [Image Processing]: Scene Analysis—color, photometry, shading
7413311
A fast multigrid algorithm for mesh deformation
In this paper, we present a multigrid technique for efficiently deforming large surface and volume meshes. We show that a previous least-squares formulation for distortion minimization reduces to a Laplacian system on a general graph structure for which we derive an analytic expression. We then describe an efficient multigrid algorithm for solving the relevant equations. Here we develop novel prolongation and restriction operators used in the multigrid cycles. Combined with a simple but effective graph coarsening strategy, our algorithm can outperform other multigrid solvers and the factorization stage of direct solvers in both time and memory costs for large meshes. It is demonstrated that our solver can trade off accuracy for speed to achieve greater interactivity, which is attractive for manipulating large meshes. Our multigrid solver is particularly well suited for a mesh editing environment which does not permit extensive precomputation. Experimental evidence of these advantages is provided on a number of meshes with a wide range of size. With our mesh deformation solver, we also successfully demonstrate that visually appealing mesh animations can be generated from both motion capture data and a single base mesh even when they are inconsistent.
2838174
Minimizing the number of programming steps for diagnosis of interconnect faults in FPGAs
This paper presents a procedure to diagnose single faults in SRAM based FPGAs. The procedure is nonadaptive and requires six programming steps to give the exact position and type of any single fault in a FPGA. It is proved that the number of programming steps required for the procedure is minimal for a non-adaptive procedure with the given interconnect model.