48,899 research outputs found
Advanced content-based semantic scene analysis and information retrieval: the SCHEMA project
The aim of the SCHEMA Network of Excellence is to bring together a critical mass of universities, research centers, industrial partners and end users, in order to design a reference system for content-based semantic scene analysis, interpretation and understanding. Relevant research areas include: content-based multimedia analysis and automatic annotation of semantic multimedia content, combined textual and multimedia information retrieval, semantic -web, MPEG-7 and MPEG-21 standards, user interfaces and human factors. In this paper, recent advances in content-based analysis, indexing and retrieval of digital media within the SCHEMA Network are presented. These advances will be integrated in the SCHEMA module-based, expandable reference system
The structure and composition statistics of 6A binary and ternary crystalline materials
The fundamental principles underlying the arrangement of elements into solid
compounds with an enormous variety of crystal structures are still largely
unknown. This study presents a general overview of the structure types
appearing in an important subset of the solid compounds, i.e., binary and
ternary compounds of the 6A column oxides, sulfides and selenides. It contains
an analysis of these compounds, including the prevalence of various structure
types, their symmetry properties, compositions, stoichiometries and unit cell
sizes. It is found that these compound families include preferred
stoichiometries and structure types that may reflect both their specific
chemistry and research bias in the available empirical data. Identification of
non-overlapping gaps and missing stoichiometries in these structure populations
may be used as guidance in the search for new materials.Comment: 19 pages, 13 figure
The Missing Data Encoder: Cross-Channel Image Completion\\with Hide-And-Seek Adversarial Network
Image completion is the problem of generating whole images from fragments
only. It encompasses inpainting (generating a patch given its surrounding),
reverse inpainting/extrapolation (generating the periphery given the central
patch) as well as colorization (generating one or several channels given other
ones). In this paper, we employ a deep network to perform image completion,
with adversarial training as well as perceptual and completion losses, and call
it the ``missing data encoder'' (MDE). We consider several configurations based
on how the seed fragments are chosen. We show that training MDE for ``random
extrapolation and colorization'' (MDE-REC), i.e. using random
channel-independent fragments, allows a better capture of the image semantics
and geometry. MDE training makes use of a novel ``hide-and-seek'' adversarial
loss, where the discriminator seeks the original non-masked regions, while the
generator tries to hide them. We validate our models both qualitatively and
quantitatively on several datasets, showing their interest for image
completion, unsupervised representation learning as well as face occlusion
handling
Quality of Service for Information Access
Information is available in many forms from different sources, in distributed locations; access to information is supported by networks of varying performance; the cost of accessing and transporting the information varies for both the source and the transport route. Users who vary in their preferences, background knowledge required to interpret the information and motivation for accessing it, gather information to perform many different tasks. This position paper outlines some of these variations in information provision and access, and explores the impact these variations have on the userâs task performance, and the possibilities they make available to adapt the user interface for the presentation of information
A Density-Based Approach to the Retrieval of Top-K Spatial Textual Clusters
Keyword-based web queries with local intent retrieve web content that is
relevant to supplied keywords and that represent points of interest that are
near the query location. Two broad categories of such queries exist. The first
encompasses queries that retrieve single spatial web objects that each satisfy
the query arguments. Most proposals belong to this category. The second
category, to which this paper's proposal belongs, encompasses queries that
support exploratory user behavior and retrieve sets of objects that represent
regions of space that may be of interest to the user. Specifically, the paper
proposes a new type of query, namely the top-k spatial textual clusters (k-STC)
query that returns the top-k clusters that (i) are located the closest to a
given query location, (ii) contain the most relevant objects with regard to
given query keywords, and (iii) have an object density that exceeds a given
threshold. To compute this query, we propose a basic algorithm that relies on
on-line density-based clustering and exploits an early stop condition. To
improve the response time, we design an advanced approach that includes three
techniques: (i) an object skipping rule, (ii) spatially gridded posting lists,
and (iii) a fast range query algorithm. An empirical study on real data
demonstrates that the paper's proposals offer scalability and are capable of
excellent performance
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