Papers by Jennifer Trelewicz
A sampling approach to bandlimiting instantaneously companded signals
Conference Record of The Thirtieth Asilomar Conference on Signals, Systems and Computers
A well-known theorem of Beurling demonstrates that distinct bandlimited signals remain distinct a... more A well-known theorem of Beurling demonstrates that distinct bandlimited signals remain distinct after instantaneous companding and ideal low-pass filtering. Motivated by this result, Landau (1960) developed an iterative method for recovering a bandlimited signal after companding and low-pass filtering. This paper describes an alternative to low-pass filtering for restoring the original bandwidth to a companded bandlimited signal prior to transmission
Analysis of Business Connections Utilizing Theory of Topology of Random Graphs
AIP Conference Proceedings, 2006
ABSTRACT A business ecosystem is a system that describes interactions between organizations. In t... more ABSTRACT A business ecosystem is a system that describes interactions between organizations. In this paper, we build a theoretical framework that defines a model which can be used to analyze the business ecosystem. The basic concepts within the framework are organizations, business connections, and market, that are all defined in the paper. Many researchers analyze the performance and structure of business using the workflow of the business. Our work in business connections answers a different set of questions, concerning the monetary value in the business ecosystem, rather than the task‐interaction view that is provided by workflow analysis.
Method and system for providing a high quality halftoned image
Method, apparatus and article of manufacture for modifying printing based upon direct on-the-fly media characteristic parameters
Method and apparatus for electromagnetic drying of printed media
Faster transforms using early aborts and precision refinements
Analysis of impact of change in an organizational entity
Method and system for scaling a signal sample rate
Raster data compression apparatus and method
System and method for diagnosing printer problems and notarizing prints by evaluating embedded data
Efficient scaling in transform domain
Burst error compensation for a two-dimensional channel
1999 IEEE International Conference on Acoustics, Speech, and Signal Processing. Proceedings. ICASSP99 (Cat. No.99CH36258), 1999
In an optical channel for a digital holographic data storage system, burst errors, in the form of... more In an optical channel for a digital holographic data storage system, burst errors, in the form of severe amplitude compression, are experienced in the vicinity of dust and other optical aberrations in the channel. The locations of these burst errors are approximately fixed over a range of perturbations in magnification and vertical-horizontal position. In a calibrated channel, lower error rates
A metric for compression with the Burrows-Wheeler and move-to-front transforms
Error diffusion method for resampling in the transform domain
The algorithm presented here addresses the problem of resampling images or signals with computati... more The algorithm presented here addresses the problem of resampling images or signals with computational efficiency in real time, with an algorithm capable of providing arbitrary resampling ratios that are determined on-the-fly. The algorithm uses a set of resampling algorithms with predetermined, fixed resampling ratios, utilizing Error Diffusion (ED) to obtain an arbitrary resampling factor between two fixed values. Specifically, optimized implementations for the collection of fixed resampling values may be pre-calculated offline, and our algorithm can achieve resampling ratios that lie between any two of these fixed resampling ratios. Because the fixed resampling values can be precalculated based on any number of prior fast resampling algorithms, resampling can be performed either in the transform domain or in the sample domain. The algorithm is appropriate for implementation in software or hardware. The behavior of this ED approach is compared to that of conventional scaling approa...
Natural language insensitive short textual string compression
SPIE Proceedings, 2004
ABSTRACT There are applications (such as Internet search engines) where short textual strings, fo... more ABSTRACT There are applications (such as Internet search engines) where short textual strings, for example abstracts or pieces of Web pages, need to be compressed independently of each other. The usual adaptive compression algorithms perform poorly on these short strings due to the lack of necessary data to learn. In this manuscript, we introduce a compression algorithm targeting short text strings; e.g., containing a few hundred symbols. We also target natural language insensitivity, to facilitate its robust compression and fast implementation. The algorithm is based on the following findings. Applying the move-to-front transform (MTFT) after the Burrows-Wheeler transform (BWT) brings the short textual strings to a "normalized form" where the distribution of the resulting "ranks" has a shape similar over the set of natural language strings. This facilitates the use of a static coding method with few variations, which we call shortBWT, where no on-line learning is needed, to encode the ranks. Finally, for short strings, shortBWT runs very fast because the strings fit into the cache of most current computers. The introduction for this paper will review the mathematical bases of BWT and MTF, it will also review our recently published metric for rapidly pre-characterizing the compressibility of such short textual strings when using these transforms.
System analysis of power control policies for VBR traffic
2000 IEEE Wireless Communications and Networking Conference. Conference Record (Cat. No.00TH8540), 2000
In a code division multiple access system, the quality of service delivered to a user depends on ... more In a code division multiple access system, the quality of service delivered to a user depends on its transmission power and the level of multiple access interference. When variable bit-rate users are statistically identical, conventional power control (uniform) is used to guarantee fairness of service to the users in the system by avoiding the near-far problem, However, when the probability
Efficient Computation of Multiplierless Filters in Embedded Systems Employing an Optimal Approximation Method
International Journal of Computational Methods, 2006
An integerization technique for creating fixed integer transforms with computationally optimal re... more An integerization technique for creating fixed integer transforms with computationally optimal representations is presented, and the improved performance in embedded systems by employing these integerized implementations is explored. This technique uses an optimal approximation algorithm that finds the lowest-length fractional representation of the rational numbers. The integer transform approximation allows multiplication to be replaced by shift-and-add operations in hardware systems; where multiplication can take several cycles, shifts and adds take one or fewer cycles each. The multiplierless implementation furthermore benefits from employing the proposed method to represent the floating-point coefficients in very high precision requirement areas, like decimation filter design. This paper is strongly oriented around the design of coefficients with hardware constraints in mind, such as minimizing the number of required adds/subtracts and shifts required for some engineering algori...
IEEE Signal Processing Magazine, 2002
IEEE Transactions on Signal Processing, 2004
We discuss two new algorithms for the calculation of simultaneous rational approximations with sp... more We discuss two new algorithms for the calculation of simultaneous rational approximations with specific computational characteristics. These approximations are used for efficient calculation of linear transforms. We develop an application in compression using the discrete cosine transform (DCT); however, the methods are also applicable to other integer transforms. To facilitate efficient multiplierless implementation for small field programmable gate arrays (FPGAs) or other low-cost processing elements, the rational approximations must have controlled precision (bits), and the numerators must use a minimum number of adds and shifts over the coefficient vector (minimum "length" representation). Our first method uses successive approximation of the coefficients in a suboptimal algorithm with low computational complexity to achieve low-length representations. The convergence of this method is analyzed, along with the closeness of the approximations. The suitability of this method for computational implementation, along with the quality of its representations, are evaluated in the context of continued fraction algorithms. The method is shown to be suitable for real-time computation for algorithms such as JPEG-2000. The second method, which finds the lowest length representation, requires more computation but is tractable for offline computation. This method employs search tree pruning and provides a lower bound for the representation length at each iteration. The computational complexity of this method is analyzed and compared with experimental results.
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Papers by Jennifer Trelewicz