Presents two new algorithms for performing arithmetic coding without employing multiplication and discusses their implementation requirements. The first algorithm, suitable for an alphabet of arbitrary size, reduces the worst case excess length to under 0.8%. The second algorithm, suitable only for alphabets of less than 12 symbols, allows even…

Presents an inference algorithm that produces a weighted finite automata (WFA), in particular, the grayness functions of graytone images. Image-data compression results based on the new inference algorithm produces a WFA with a relatively small number of edges. Image-data compression results alone and in combination with wavelets are discussed.…

Discussion of data storage technology for multimedia materials highlights a new signature file method that divides files into variable-sized vertical frames to optimize response time using partial query evaluation. Real data experiments that tested the response time are reported, and future work is discussed. (Author/LRW)

Presents a technique for storing compound keywords with information about short and long component (SC and LC) keywords by extending Aho and Corasick (AC) string-pattern matching-machine for a finite number of keywords. Results for 38 Japanese text files reveal the extended AC machine is three to six times faster than the original AC machine in SC…

Analyzes the properties of genetic sequences that cause the failure of classical algorithms used for data compression. A lossless algorithm, which compresses the information contained in DNA and RNA sequences by detecting regularities such as palindromes, is presented. This algorithm combines substitutional and statistical methods and appears to…

Describes an approximate document ranking process that uses a compact array of in-memory, low-precision approximations for document length. Combined with another rule for reducing the memory required by partial similarity accumulators, the approximation heuristic allows the ranking of large document collections using less than one byte of memory…