3,567 research outputs found
GASP : Geometric Association with Surface Patches
A fundamental challenge to sensory processing tasks in perception and
robotics is the problem of obtaining data associations across views. We present
a robust solution for ascertaining potentially dense surface patch (superpixel)
associations, requiring just range information. Our approach involves
decomposition of a view into regularized surface patches. We represent them as
sequences expressing geometry invariantly over their superpixel neighborhoods,
as uniquely consistent partial orderings. We match these representations
through an optimal sequence comparison metric based on the Damerau-Levenshtein
distance - enabling robust association with quadratic complexity (in contrast
to hitherto employed joint matching formulations which are NP-complete). The
approach is able to perform under wide baselines, heavy rotations, partial
overlaps, significant occlusions and sensor noise.
The technique does not require any priors -- motion or otherwise, and does
not make restrictive assumptions on scene structure and sensor movement. It
does not require appearance -- is hence more widely applicable than appearance
reliant methods, and invulnerable to related ambiguities such as textureless or
aliased content. We present promising qualitative and quantitative results
under diverse settings, along with comparatives with popular approaches based
on range as well as RGB-D data.Comment: International Conference on 3D Vision, 201
On palimpsests in neural memory: an information theory viewpoint
The finite capacity of neural memory and the
reconsolidation phenomenon suggest it is important to be able
to update stored information as in a palimpsest, where new
information overwrites old information. Moreover, changing
information in memory is metabolically costly. In this paper, we
suggest that information-theoretic approaches may inform the
fundamental limits in constructing such a memory system. In
particular, we define malleable coding, that considers not only
representation length but also ease of representation update,
thereby encouraging some form of recycling to convert an old
codeword into a new one. Malleability cost is the difficulty of
synchronizing compressed versions, and malleable codes are of
particular interest when representing information and modifying
the representation are both expensive. We examine the tradeoff
between compression efficiency and malleability cost, under a
malleability metric defined with respect to a string edit distance.
This introduces a metric topology to the compressed domain. We
characterize the exact set of achievable rates and malleability as
the solution of a subgraph isomorphism problem. This is all done
within the optimization approach to biology framework.Accepted manuscrip
Recovering Grammar Relationships for the Java Language Specification
Grammar convergence is a method that helps discovering relationships between
different grammars of the same language or different language versions. The key
element of the method is the operational, transformation-based representation
of those relationships. Given input grammars for convergence, they are
transformed until they are structurally equal. The transformations are composed
from primitive operators; properties of these operators and the composed chains
provide quantitative and qualitative insight into the relationships between the
grammars at hand. We describe a refined method for grammar convergence, and we
use it in a major study, where we recover the relationships between all the
grammars that occur in the different versions of the Java Language
Specification (JLS). The relationships are represented as grammar
transformation chains that capture all accidental or intended differences
between the JLS grammars. This method is mechanized and driven by nominal and
structural differences between pairs of grammars that are subject to
asymmetric, binary convergence steps. We present the underlying operator suite
for grammar transformation in detail, and we illustrate the suite with many
examples of transformations on the JLS grammars. We also describe the
extraction effort, which was needed to make the JLS grammars amenable to
automated processing. We include substantial metadata about the convergence
process for the JLS so that the effort becomes reproducible and transparent
Nonattribution Properties of JPEG Quantization Tables
In digital forensics, source camera identification of digital images has drawn attention in recent years. An image does contain information of its camera and/or editing software somewhere in it. But the interest of this research is to find manufacturers (henceforth will be called make and model) of a camera using only the header information, such as quantization table and huffman table, of the JPEG encoding. Having done research on around 110, 000 images, we reached to state that For all practical purposes, using quantization and huffman tables alone to predict a camera make and model isn\u27t a viable approach . We found no correlation between quantization and huffman tables of images and makes of camera. Rather, quantization or huffman table is determined by the quality factors like resolution, RGB values, intensity etc.of an image and standard settings of the camera
A Frame Work for Parallel String Matching- A Computational Approach with Omega Model
Now a day2019;s parallel string matching problem is attracted by so many researchers because of the importance in information retrieval systems. While it is very easily stated and many of the simple algorithms perform very well in practice, numerous works have been published on the subject and research is still very active. In this paper we propose a omega parallel computing model for parallel string matching. Experimental results show that, on a multi-processor system, the omega model implementation of the proposed parallel string matching algorithm can reduce string matching time by more than 40%
The optimality of word lengths. Theoretical foundations and an empirical study
Zipf's law of abbreviation, namely the tendency of more frequent words to be
shorter, has been viewed as a manifestation of compression, i.e. the
minimization of the length of forms -- a universal principle of natural
communication. Although the claim that languages are optimized has become
trendy, attempts to measure the degree of optimization of languages have been
rather scarce. Here we present two optimality scores that are dualy normalized,
namely, they are normalized with respect to both the minimum and the random
baseline. We analyze the theoretical and statistical pros and cons of these and
other scores. Harnessing the best score, we quantify for the first time the
degree of optimality of word lengths in languages. This indicates that
languages are optimized to 62 or 67 percent on average (depending on the
source) when word lengths are measured in characters, and to 65 percent on
average when word lengths are measured in time. In general, spoken word
durations are more optimized than written word lengths in characters. Our work
paves the way to measure the degree of optimality of the vocalizations or
gestures of other species, and to compare them against written, spoken, or
signed human languages.Comment: On the one hand, the article has been reduced: analyses of the law of
abbreviation and some of the methods have been moved to another article;
appendix B has been reduced. On the other hand, various parts have been
rewritten for clarity; new figures have been added to ease the understanding
of the scores; new citations added. Many typos have been correcte
Experience with a Workflow using MS Word and a DOCX to TEI Converter
In this contribution we summarize our experience in edition projects with the conversion from DOCX files to TEI-XML files. A tool called DOCX2TEI, developed in our team, is capable of transforming DOCX files automatically to TEI files without the need of manual post-processing of conversion results by editors. However, for this to function properly pertinent programming knowledge is required to make the necessary adaptations on DOCX2TEI. We compare DOCX2TEI with other tools capable of producing TEI files out of DOCX files. At the end of the paper we will present the lesson learned from deploying and using this tool
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