Ziv-Lempel coding is currently one of the more practical data compression schemes. It operates by replacing a substring of a text with a pointer to its longest previous occurrence in the input, for each coding step. Decoding a compressed le is very fast, but encoding involves searching at each coding step to nd the longest match for the next few characters. This paper presents eight data struct...

SUMMARY Ziv–Lempel coding is currently one of the more practical data compression schemes. It operates by replacing a substring of a text with a pointer to its longest previous occurrence in the input, for each coding step. Decoding a compressed file is very fast, but encoding involves searching at each coding step to find the longest match for the next few characters. This paper presents eight...

The World Wide Web has been extensively developed since its first appearance two decades ago. Various applications on the Web have unprecedentedly changed humans’ life. Although the explosive growth and spread of the Web have resulted in a huge information repository, yet it is still under-utilized due to the difficulty in automated information extraction (IE) caused by the heterogeneity of Web...

Nowadays, with huge progress in digital imaging, new image processing methods are needed to manage digital images stored on disks. Image retrieval has been one of the most challengeable fields in digital image processing which means searching in a big database in order to represent similar images to the query image. Although many efficient researches have been performed for this topic so far, t...

Interpolation of field data from unstructured meshes requires the potentially expensive identification of the finite element or volume within which the interpolating point lies. A number of geometric search algorithms have been proposed to reduce this expense at the cost of setting up and storing additional search tables. Using tetrahedral finite element models we show that a structured auxilia...

This paper presents a computational study of a digital line network design problem arising in the telecommunication industry. The objective can be formulated as that of nding an optimal degree constrained Steiner tree in a graph whose nodes and edges are weighted by costs. We develop a Tabu Search heuristic for this problem that incorporates long term memory and probabilistic move selections. W...

N-gram indexing is used in many practical applications. Spam detection, plagiarism detection or comparison of DNA reads. There are many data structures that can be used for this purpose, each with different characteristics. In this article the ternary search tree data structure is used. One improvement of ternary tree that can save up to 43% of required memory is introduced. In the second part ...

In this paper we show how a slight modification of (a, 2b)-trees allows us to perform member and neighbor queries in O(logn) time and updates in O(1) worst-case time (once the position of the inserted or deleted key is known). Our data structure is quite natural and much simpler than previous worst-case optimal solutions. It is based on two techniques : 1) bucketing, i.e., storing an ordered li...

The random hash tree and the N-tree were introduced by Ehrlich in 1981. In the random hash tree, n data points are hashed to values X1, . . . , Xn, independently and identically distributed random variables taking values that are uniformly distributed on [0, 1]. Place the Xi’s in n equal-sized buckets as in hashing with chaining. For each bucket with at least two points, repeat the same process...