Free and Open Source Software in Municipal Procurement:The Challenges and Benefits of Cooperation

The use of free and open source software by municipal governments is the exception rather than the rule. This is due to a variety of factors, including a failure of many municipal procurement policies to take into account the benefits of free software, free software vendors second-to-market status, and a lack of established free and open source software vendors in niche markets. With feasible policy shifts to improve city operations, including building upon open standards and engaging with free software communities, municipalities may be able to better leverage free and open source software to realize fully the advantages that stem from open software development

An O(n log n)-Time Algorithm for the Restricted Scaffold Assignment

The assignment problem takes as input two finite point sets S and T and establishes a correspondence between points in S and points in T, such that each point in S maps to exactly one point in T, and each point in T maps to at least one point in S. In this paper we show that this problem has an O(n log n)-time solution, provided that the points in S and T are restricted to lie on a line (linear time, if S and T are presorted).Comment: 13 pages, 8 figure

Efficient algorithms for computing distances between one-dimensional point sets

Let S and T denote sets of points on the line with the total number of points equal to n. In this thesis the focus is on computing distance measures between S and T as defined by different types of assignments . An assignment is a function, F, which pairs elements of the two sets together. In particular, we are interested in the distances given by two types of assignment. When F is a surjection between the sets, the surjection distance minimizes the sum of the costs of the pairings. When the assignment is restricted only by the property that all elements in both sets must be paired at least once, the corresponding distance measure is referred to as the link distance. After a review of the literature on assignments, including an in depth description of a foundational result for assignments on the line published by Karp and Li in 1975, new algorithms are presented which improve the computational complexity of both the surjection and link distances for one-dimensional sets. In 2003 Ben-Dor et al. proposed a O(n log n) algorithm for the surjection distance in one-dimension. We provide a counter-example to their algorithm as well as a new algorithm which has a complexity of O(n 2), improving the previous best O(n3) result of Eiter and Mannila. Our algorithm for the link distance in one-dimension also runs in O(n 2) time, improving the previous best complexity of O(n 3) also due to Eiter and Mannila

An Algorithm for Computing the Restriction Scaffold Assignment Problem in Computational Biology

Let S and T be two finite sets of points on the real line with |S| + |T | = n and |S| > |T |. The restriction scaffold assignment problem in computational biology assigns each point of S to a point of T such that the sum of all the assignment costs is minimized, with the constraint that every element of T must be assigned at least one element of S. The cost of assigning an element s i of S to an element t j of T is |s i - t j |, i.e., the distance between s i and t j . In 2003 Ben-Dor, Karp, Schwikowski and Shamir [2] published an O(n logn) time algorithm for this problem. Here we provide a counter-example to their algorithm and present a new algorithm that runs in O(n ) time, improving the best previous complexity of O(n )

A Faster Algorithm for Computing the Link Distance between Two Point Sets on the Real Line

Let S and T be point sets with |S| # |T | and total cardinality n. A linking between S and T is a matching, L, between the sets where every element of S and T is matched to at least one element of the other set. The link distance is defined as the minimum-cost linking. In this note we consider a special case of the link distance where both point sets lie on the real line and the cost of matching two points is the distance between them in the L 1 metric. An O(n ) algorithm for this problem is presented, improving the previous best known complexity of O(n )

Faster Algorithms for Computing Distances between One-Dimensional Point Sets

Let S and T be two finite sets of points on the real line with |S| + |T| = n and |S| > |T|. We consider two distance measures between S and T that have applications in music information retrieval and computational biology: the surjection distance and the link distance. The former is called the restriction scaffold assignment problem in computational biology, and assigns each point of S to a point of T such that the sum of all the assignment costs is minimized, with the constraint that every element of T must be assigned at least one element of S. The cost of assigning an element s i of S to an element t j of T is |s i - t j |, i.e., the distance between s i and t j . In 2003 Ben-Dor, Karp, Schwikowski and Shamir [2] published an O(n log n) time algorithm for this problem. Here w

Efficient Many-To-Many Point Matching in One Dimension

Appears in Graphs and Combinatorics, vol. 23 (2007), supplement, Computational Geometry and Graph Theory. The Akiyama-Chvatal Festschrift. The original publication is available at www.springerlink.com. Abstract. Let S and T be two sets of points with total cardinality n. The minimum-cost many-to-many matching problem matches each point in S to at least one point in T and each point in T to at least one point in S, such that sum of the matching costs is minimized. Here we examine the special case where both S and T lie on the line and the cost of matching s ∈ S to t ∈ T is equal to the distance between s and t. In this context, we provide an algorithm that determines a minimum-cost many-to-many matching in O(n log n) time, improving the previous best time complexity of O(n 2) for the same problem. 1

Efficient many-To-many point matching in one dimension

SCOPUS: ar.jinfo:eu-repo/semantics/publishe