We propose a compress-forward (CF) strategy for relaying over parallel Gaussian channels. The proposed CF strategy compresses received signals at the relay under a constraint on the product of their allowable distortions and forwards them to the destination over all subchannels. Power allocation over all subchannels at both the source and the relay and bit allocation for compressing received si...

In this work we deal with the problem of how to squeeze multiple ciphertexts without losing original message information. To do so, we formalize the notion of decomposability for public-key encryption and investigate why adding decomposability is challenging. We construct an ElGamal encryption scheme over extension fields, and show that it supports the efficient decomposition. We then analyze s...

It has been suggested that space, time and number are represented on a common subjective scale. Saccadic eye movements provide a fascinating test. Saccades compress the perceived magnitude of spatial separations and temporal intervals to approximately half of their true value. The question arises as to whether saccades also compress number. They do, and compression follows a very similar time c...

| We consider the problem of describing the exact compression performance of a classical Shannon random codebook, for lossy source coding at a xed distortion level. For a memoryless source with a nite alphabet and a single-letter distortion measure, we address the following questions: (1) Are all random codebooks equally good? (2) What is the pointwise redundancy of a typical random codebook? (...

Data compression methods can be classified into two groups: lossless and lossy. Usually the latter achieves a higher compression ratio than the former. However, to develop a lossy compression method, we have to know, for a given type of data, what information can be discarded without significant degradation of the data quality. A usual way to obtain such knowledge is by experiments. For example...

One method to compress a pair of stereo images is to compress the first image independently and then compress the second image by estimating the disparity between the two images. The first image was transformed using 2-D Discrete Cosine Transform, quantized using the JPEG quantization matrix and finally encoded into a bitstream using arithmetic encoding. The disparity between the two images was...

We present an adaptive compression environment (ACE) that uses both underlying resource performance (network and CPU) predictions and the compressibility of the data stream to perform on-the-fly compression. ACE couples technologies from Computational Grid Computing and dynamic compilation research to predict the efficacy of using compression and to intercept and compress socket-based communica...

Several methods have been proposed for compressing the linkage data of a Web graph. Among them, the method proposed by Boldi and Vigna is known as the most efficient one. In the paper, we propose a new method to compress a Web graph. Our method is more efficient than theirs with respect to the size of the compressed data. For example, our method needs only 1.99 bits per link to compress a Web g...

We propose a lossless algorithm to compress the information contained in DNA sequences. None of the available universal algorithms compress such data. This is due to the speciicity of genetic information. Our method is based on regularities, such as the presence of palindromes, in the DNA. The results we obtain, although not satisfactory, are far beyond classical algorithms.

Continuing experimental work on SAS data set compression presented at NESUG in 2004, I designed another two-factor factorial experiment. My first factor compares the three kinds of data set compression offered by SAS on UNIX; the SAS DATA set OPTIONS COMPRESS=CHAR, COMPRESS=BINARY and SAS sequential format files created with the V9TAPE engine, three UNIX file compression algorithms; compress, g...