Efficient processing of top-k queries on multidimensional grids is a common requirement in information retrieval and data mining, for example in OLAP cubes. We introduce a data structure, the K-treap, that represents grids in compact form and supports efficient prioritized range queries. We compare the K-treap with state-of-the-art solutions on synthetic and real-world datasets, showing that it...

The simultaneous need for a wide angle of eld and high resolution has led to the use of spatially variant sensors in active vision systems. The use of such sensors however necessitates the existence of gaze control mechanisms for guiding the foveal high resolution region of the sensor to points of interest in the visual world. While bottom-up alerting cues such as motion have previously been us...

Virtually every modern search application, either desktop, web, or mobile, features some kind of query auto-completion. In its basic form, the problem consists in retrieving from a string set a small number of completions, i.e. strings beginning with a given prefix, that have the highest scores according to some static ranking. In this paper, we focus on the case where the string set is so larg...

This paper introduces the Human Information Workspace (HISpace) as a test-bed for evaluating new information exploration mechanisms. In moving from dated interaction devices and small computer monitors, we aim to utilize more natural surfaces such as tables and walls as our interaction space. In testing our theories, we have produced a number of gaming applications as test cases. Here, we repor...

The purpose of this note is to answer a question I asked in 2010 in [Grinbe10]. It concerns the kernel of a certain operator on the tensor algebra T (L) of a free module L over a commutative ring k (an operator that picks out a factor from a tensor and moves it to the front, and takes an alternating sum of the results ranging over all factors – an algebraic version of what probabilists call the...

We present a method to enlarge the phase space of a canonical Hamiltonian System in order to remove coordinate singularities arising from a nontrivial topology of the connguration space. This \innation" preserves the canonical structure of the system and generates new constants of motion that realize the constraints. As a rst illustrative example the spherical pendulum is innated by embedding t...

The inverted index is the backbone of modern web search engines. For each word in a collection of web documents, the index records the list of documents where this word occurs. Given a set of query words, the job of a search engine is to output a ranked list of the most relevant documents containing the query. However, if the query consists of an arbitrary string — which can be a partial word, ...

We consider the problem of retrieving the k documents from a collection of strings where a given pattern P appears most often. We show that, by representing the collection using a Compressed Suffix Array CSA, a data structure using the asymptotically optimal |CSA|+o(n) bits can answer queries in the time needed by CSA to find the suffix array interval of the pattern plus O(k lg k lg n) accesses...

In previous work, singular points (or top points) in the scale space representation of generic images have proven valuable for image matching. In this paper, we propose a construction that encodes the scale space description of top points in the form of a directed acyclic graph. This representation allows us to utilize graph matching algorithms for comparing images represented in terms of top p...

Equations of motion of an axially symmetric sphere rolling and sliding on a plane are usually taken as model of the tippe top. We study these equations in the nonsliding regime both in the vector notation and in the Euler angle variables when they admit three integrals of motion that are linear and quadratic in momenta. In the Euler angle variables (θ, φ, ψ) these integrals give separation equa...