Journal ArticleDOI
Compression of individual sequences via variable-rate coding
Jacob Ziv,A. Lempel +1 more
TLDR
The proposed concept of compressibility is shown to play a role analogous to that of entropy in classical information theory where one deals with probabilistic ensembles of sequences rather than with individual sequences.Abstract:
Compressibility of individual sequences by the class of generalized finite-state information-lossless encoders is investigated. These encoders can operate in a variable-rate mode as well as a fixed-rate one, and they allow for any finite-state scheme of variable-length-to-variable-length coding. For every individual infinite sequence x a quantity \rho(x) is defined, called the compressibility of x , which is shown to be the asymptotically attainable lower bound on the compression ratio that can be achieved for x by any finite-state encoder. This is demonstrated by means of a constructive coding theorem and its converse that, apart from their asymptotic significance, also provide useful performance criteria for finite and practical data-compression tasks. The proposed concept of compressibility is also shown to play a role analogous to that of entropy in classical information theory where one deals with probabilistic ensembles of sequences rather than with individual sequences. While the definition of \rho(x) allows a different machine for each different sequence to be compressed, the constructive coding theorem leads to a universal algorithm that is asymptotically optimal for all sequences.read more
Citations
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Book ChapterDOI
String Matching with Stopper Encoding and Code Splitting
TL;DR: A semi-static compression scheme, where characters of the text are encoded as variable-length sequences of base symbols, each of which is represented by a fixed number of bits, enables faster searching of string patterns than earlier character-based compression models and the best Boyer-Moore variants in uncompressed texts.
Journal ArticleDOI
A general-purpose compression scheme for large collections
Adam Cannane,Hugh E. Williams +1 more
TL;DR: This work proposes a semistatic phrase-based approach called xray that builds a model offline using sample training data extracted from a collection, and then compresses the entire collection online in a single pass, and shows that xray is effective on both text and general-purpose collections.
Journal ArticleDOI
Distributed database design for mobile geographical applications
TL;DR: A distributed system architecture for ATIS based on recent technology is introduced and new data models for information representation are presented and data shipping for efficient query processing and function shipping for reducing communication overhead is proposed.
Journal ArticleDOI
An optimized compression algorithm for real-time ECG data transmission in wireless network of medical information systems
TL;DR: Results actually showed that the EDLZW compression ratio was 8.66, which was a performance that was 4 times better than any other recent compression method widely used today.
Journal ArticleDOI
Information-theory based optimal location management schemes for integrated multi-system wireless networks
TL;DR: It is demonstrated how an intelligent, integrated paging strategy must consider the joint residence probability distribution of a mobile node in multiple sub-networks, and it is proved that the determination of an optimal paging sequence is NP-complete.
References
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Book
Information Theory and Reliable Communication
TL;DR: This chapter discusses Coding for Discrete Sources, Techniques for Coding and Decoding, and Source Coding with a Fidelity Criterion.
Journal ArticleDOI
A universal algorithm for sequential data compression
Jacob Ziv,A. Lempel +1 more
TL;DR: The compression ratio achieved by the proposed universal code uniformly approaches the lower bounds on the compression ratios attainable by block-to-variable codes and variable- to-block codes designed to match a completely specified source.
Journal ArticleDOI
On the Complexity of Finite Sequences
A. Lempel,Jacob Ziv +1 more
TL;DR: A new approach to the problem of evaluating the complexity ("randomness") of finite sequences is presented, related to the number of steps in a self-delimiting production process by which a given sequence is presumed to be generated.
Journal ArticleDOI
Coding theorems for individual sequences
TL;DR: The finite-state complexity of a sequence plays a role similar to that of entropy in classical information theory (which deals with probabilistic ensembles of sequences rather than an individual sequence).
Journal ArticleDOI
On Information Lossless Automata of Finite Order
TL;DR: The application of the tests to finite deterministic automata is discussed and a method of constructing a decoder for a given finite automaton that is information lossless of finite order, is described.