We prove exponential lower bounds on the length of 2-query locally decodable codes. Goldreich et al. recently proved such bounds for the special case of linear locally decodable codes. Our proof shows that a 2-query locally decodable code can be decoded with only 1 quantum query, and then proves an exponential lower bound for such 1-query locally quantum-decodable codes. We also exhibit q-query...

Several years of research have suggested that the accuracy of spoken document retrieval systems is not adversely affected by speech recognition errors. Even with error rates of around 40%, the effectiveness of an IR system falls less than 10%. The paper hypothesizes that this robust behavior is the result of repetition of important words in the text—meaning that losing one or two occurrences is...

Information retrieval systems typically weight the importance of search terms according to document and collection statistics (such as by using tf idf scores, where less common terms are given higher weight). We consider here the scenario where a user can express her own subjective weighting of the importance of the terms that form the query on top of the systemgenerated weighting, and show how...

We present a family of distance measures for comparing activation patterns captured in fMRI images. We model an fMRI image as a spatial object with varying density, and measure the distance between two fMRI images using a novel fixed-radius, distribution-based Earth Mover’s Distance that is computable in polynomial time. We also present two simplified formulations for the distance computation w...

This article proposes a content-based indexing and retrieval (CBIR) system based on query-by-visual-example using hierarchical binary signatures. Binary signatures are obtained through a described binarization process of classical features (color, texture and shape). The Hamming binary distance (based on binary XOR operation) is used for computing distances. This technique was tested on a real ...

In this paper, we present a hierarchical entropy-based representation (HER) for one-dimensional signals. Any signal can be effectively represented by means of a vector containing the energy values related to its most important points, i.e. the maxima, together with their relative locations along the time axis. Such a representation has been applied to a database containing several shapes repres...

Time series representations are common in MIR applications such as query-by-humming, where a sung query might be represented by a series of ‘notes’ for database retrieval. While such a transcription into (pitch, duration) pairs is convenient and musically intuitive, there is no evidence that it is an optimal representation. The present work explores three time series representations for sung qu...

Ever since text processors became popular, users have dreamt of handling documents printed on paper as comfortably as electronic ones, with full text search typically appearing very close to the top of the wish list. This paper presents the design of a prototype system that takes a step into this direction. The user’s desktop is continuously monitored and of each detected document a high resolu...

Image classification and retrieval systems have gained more attention because of easier access to high-tech medical imaging. However, the lack of availability of large-scaled balanced labelled data in medicine is still a challenge. Simplicity, practicality, efficiency, and effectiveness are the main targets in medical domain. To achieve these goals, Radon transformation, which is a well-known t...