PUBLIC MARKS with search algorithm

We're seeing a lot of action in the key/value map/reduce world lately. On the one hand this is because simpler stuff scales more simply, and on the other because key/value and B-Tree stores map cleanly to some fundamental algorithms.

We present a system that composes a realistic picture from a simple freehand sketch annotated with text labels. The composed picture is generated by seamlessly stitching several photographs in agreement with the sketch and text labels; these are found by searching the Internet. Although online image search generates many inappropriate results, our system is able to automatically select suitable photographs to generate a high quality composition, using a filtering scheme to exclude undesirable images. We also provide a novel image blending algorithm to allow seamless image composition. Each blending result is given a numeric score, allowing us to find an optimal combination of discovered images. Experimental results show the method is very successful; we also evaluate our system using the results from two user studies.

The Porter stemming algorithm (or ‘Porter stemmer’) is a process for removing the commoner morphological and inflexional endings from words in English. Its main use is as part of a term normalisation process that is usually done when setting up Information Retrieval systems.

An obsessive blackmailer writes anonymous messages by by cut-and-pasting letters from newspapers. Being obsessive, the blackmailer only writes messages which can be composed entirely from a single newspaper.

word aligned

Devise an algorithm which determines whether a given message can be written using a given newspaper.

GeographicLib is a small set of C classes for performing conversions between geographic, UTM, UPS, MGRS, geocentric, and local cartesian coordinates and for solving geodesic problems. The emphasis is on returning accurate results with errors close to round-off (about 5–15 nm). In addition, various properties of the Transverse Mercator Projection are described and an accurate algorithm for Geodesics on the Ellipsoid is given.

As software becomes more and more complex, it is more and more important to structure it well. Well-structured software is easy to write, easy to debug, and provides a collection of modules that can be re-used to reduce future programming costs. Conventional languages place conceptual limits on the way problems can be modularised. Functional languages push those limits back. In this paper we show that two features of functional languages in particular, higher-order functions and lazy evaluation, can contribute greatly to modularity. As examples, we manipulate lists and trees, program several numerical algorithms, and implement the alpha-beta heuristic (an algorithm from Artificial Intelligence used in game-playing programs). Since modularity is the key to successful programming, functional languages are vitally important to the real world.

work out the algorithm (along with accompanying mathematics) and code for Craig Reynolds’ Path Following example.

We present a framework for analyzing privacy and anonymity in social networks, and develop a new re-identification algorithm targeting anonymized social-network graphs. To demonstrate its effectiveness on real-world networks, we show that a third of the users who have accounts on both Twitter, a popular microblogging service, and Flickr, an online photo-sharing site, can be re-identified in the anonymous Twitter graph with only a 12% error rate.

Keeping two or more copies of the same document synchronized with each other in real-time is a complex challenge. This paper describes the differential synchronization algorithm. Differential synchronization offers scalability, fault-tolerance, and responsive collaborative editing across an unreliable network.

7-zip and the algorithm it uses (LZMA) is not that common on UNIX-like operating systems. It is well-known as a free alternative for WinZip on Windows systems and was started back in 1998. For Ubuntu p7zip – a port of 7-zip to POSIX – is available in universe (sudo apt-get install p7zip).