Although a distributed index on a distributed hash table (DHT) enables efficient document query processing in Peer-to-Peer information retrieval (P2P IR), the index costs a lot to construct and it tends to be an unfair management because of the unbalanced term frequency distribution. We devised a new distributed index, named Huffman-DHT, for P2P IR. The new index uses an algorithm similar to Hu...

3 Probability Coding 10 3.1 Prefix Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 10 3.1.1 Relationship to Entropy . . . . . . . . . . . . . . . . . . . . . . . . . . . 11 3.2 Huffman Codes . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 13 3.2.1 Combining Messages . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 15 3.2.2 Minim...

This paper describes the derivation of the T-complexity and T-information theory from the decomposition of finite strings, based on the duality of strings and variable-length T-codes. It further outlines its similarity to the string parsing algorithm by Lempel and Ziv. In its first version [15], it was intended as a summary of work published mainly by Titchener and Nicolescu. Apart from minor c...

A canonical Huffman code is an optimal prefix-free compression whose codewords enumerated in the lexicographical order form a list of binary words non-decreasing lengths. Gagie et al. (2015) gave representation this coding capable encoding and decoding symbol constant worst-case time. It uses σlg⁡ℓmax+o(σ)+O(ℓmax2) bits space, where σ ℓmax are alphabet size maximum codeword length, respectively...

Novel coding schemes are introduced and relationships between optimal codes and Huffman codes are discussed. It is shown that, for finite source alphabets, the Huffman coding is the optimal coding, and conversely the optimal coding needs not to be the Huffman coding. It is also proven that there always exists the optimal coding for infinite source alphabets. We show that for every random variab...