When we search from a huge amount of documents, we often specify several keywords and use conjunctive queries to narrow the result of the search. Though the searched documents contain all keywords, positions of the keywords are usually not considered. As the result, the search result contains some meaningless documents. It is therefore e ective to rank documents according to proximity of keywor...

This extended abstract gives an overview on two contentbased retrieval algorithms for symbolic music, developed earlier in the C-BRAHMS group [1], that took part in the Symbolic Melodic Similarity and Query by Singing/Humming tasks of the MIREX 2006 contest [3, 4]. Given two excerpts of symbolically encoded monophonic or polyphonic music, the query pattern and the target music, the purpose of t...

The paper introduces an algorithm dealing with polygons with non-stable borders. Such polygons may appear because of measuring errors or during scanning and vectorisation of blueprints. The aim of the algorithm is to remove these errors within prescribed tolerance. The algorithm uses a sweepline approach and works in two steps. In the first step, all non-stable areas are determined and in the s...

We present an implementation of the Train Algorithm, an incremental collection scheme for reclamation of mature garbage in generation-based memory management systems. To the best of our knowledge, this is the rst Train Algorithm implementation ever. Using the algorithm, the traditional mark-sweep garbage collector employed by the Mjjlner run-time system for the object-oriented BETA programming ...

We present an approach that extends the BentleyOttmann sweep-line algorithm [3] to the exact computation of the topology of arrangements induced by non-singular algebraic curves of arbitrary degrees. Algebraic curves of degree greater than 1 are difficult to handle in case one is interested in exact and efficient solutions. In general, the coordinates of intersection points of two curves are no...

In this paper, we propose an improved plumb-line algorithm, the Partial-Scan Plumb-Line (PSPL) algorithm, to solve the point-in-region problem. In the PSPL algorithm, every edge of the region (or polygon) is represented as two half segments, and all half segments of the region are sorted according to their dominating points. This is a standard representation for regions in spatial databases, pr...

One of the most representative and studied Distance-Based Queries in Spatial Databases is the K-Closest-Pairs Query (KCPQ). This query involves two spatial data sets and a distance function to measure the degree of closeness, along with a given number K of elements of the result. The output is a set of pairs of objects (with one object element from each set), with the K lowest distances. In thi...

Algebraic speciications allied to rewriting are used more and more often in design and logical prototyping of programs. We show how these techniques can be applied to a basic problem in computational geometry, namely the construction of planar subdivisions. We build up a simple, complete and convergent system of rules to cope with this problem and show how it is transformed to describe concrete...

We introduce a general framework for processing a set of curves defined on a continuous two-dimensional parametric surface, while sweeping the parameter space. A major goal of our work is to maximize code reuse in implementing algorithms that employ the prevalent sweep-line paradigm, and consequently to minimize the effort needed to extend the implementation of the paradigm to various surfaces ...