81,730 research outputs found
Federated and decentralized metadata system
A federated and decentralized metadata system and its application to open source software package origin, license and vulnerabilities metadata sharing and curation.This publication describes a new system and approach that supports decentralized and federated metadata aggregation and sharing to remove data silos, distribute control, improve availability and enable distributed and social review over this metadata.Such a system is designed to effectively allow large scale sharing and exchange of metadata using open systems and to support the efficient curation, and peer review of the metadata through self-organizing networks of reputable or trusted peers based on social networking.This system supports decentralized and distributed metadata collection and federated multi-aggregation of the metadata to avoid single points of control, avoid walled gardens and exclusive gated access, or the lack of availability due to system failure or shutdown of a central system with a goal to improve availability, resilience of the system while lowering the overall effort and compute cost required to achieve these results
Fingerprints of intrinsic phase separation: magnetically doped two-dimensional electron gas
In addition to Anderson and Mott localization, intrinsic phase separation has
long been advocated as the third fundamental mechanism controlling the
doping-driven metal-insulator transitions. In electronic system, where charge
neutrality precludes global phase separation, it may lead to various
inhomogeneous states and dramaticahttp://arxiv.org/submit/215787/metadata arXiv
Submission metadatally affect transport. Here we theoretically predict the
precise experimental signatures of such phase-separation-driven metal-insulator
transitions. We show that anomalous transport is expected in an intermediate
regime around the transition, displaying very strong temperature and magnetic
field dependence, but very weak density dependence. Our predictions find
striking agreement with recent experiments on Mn-doped CdTe quantum wells, a
system where we identify the microscopic origin for intrinsic phase separation.Comment: 4+epsilon pages, 4 figure
Towards Real-Time, Country-Level Location Classification of Worldwide Tweets
In contrast to much previous work that has focused on location classification
of tweets restricted to a specific country, here we undertake the task in a
broader context by classifying global tweets at the country level, which is so
far unexplored in a real-time scenario. We analyse the extent to which a
tweet's country of origin can be determined by making use of eight
tweet-inherent features for classification. Furthermore, we use two datasets,
collected a year apart from each other, to analyse the extent to which a model
trained from historical tweets can still be leveraged for classification of new
tweets. With classification experiments on all 217 countries in our datasets,
as well as on the top 25 countries, we offer some insights into the best use of
tweet-inherent features for an accurate country-level classification of tweets.
We find that the use of a single feature, such as the use of tweet content
alone -- the most widely used feature in previous work -- leaves much to be
desired. Choosing an appropriate combination of both tweet content and metadata
can actually lead to substantial improvements of between 20\% and 50\%. We
observe that tweet content, the user's self-reported location and the user's
real name, all of which are inherent in a tweet and available in a real-time
scenario, are particularly useful to determine the country of origin. We also
experiment on the applicability of a model trained on historical tweets to
classify new tweets, finding that the choice of a particular combination of
features whose utility does not fade over time can actually lead to comparable
performance, avoiding the need to retrain. However, the difficulty of achieving
accurate classification increases slightly for countries with multiple
commonalities, especially for English and Spanish speaking countries.Comment: Accepted for publication in IEEE Transactions on Knowledge and Data
Engineering (IEEE TKDE
The Development of Web-Based Interface to Census Interaction Data
This project involves the development of a Web interface to origin-destination statistics from the 1991 Census (in a form that will be compatible with planned 2001 outputs). It provides the user with a set of screen-based tools for setting the parameters governing each data extraction (data set, areas, variables) in the form of a query. Traffic light icons are used to signal what the user has set so far and what remains to be done. There are options to extract different types of flow data and to generate output in different formats. The system can now be used to access the interaction flow data contained in the 1991 Special Migration Statistics Sets 1 and 2 and Special Workplace Statistics Set C. WICID has been demonstrated at the Origin-Destination Statistics Roadshows organised by GRO Scotland and held during May/June 2000 and the Census Offices have expressed interest in using the software in the Census Access Project
Collaboration Enabling Internet Resource Collection-Building Software and Technologies
Over the last decade the Library of the University of California, Riverside
and its collaborators have developed a number of systems, service designs,
and projects that utilize innovative technologies to foster better Internet
finding tools in libraries and more cooperative and efficient effort in Internet
link and metadata collection building. The open-source software
and projects discussed represent appropriate technologies and sustainable
strategies that we believe will help Internet portals, digital libraries, virtual libraries,
library catalogs-with-portal-like-capabilities (IPDVLCs), and related
collection-building efforts in academia to better scale and more accurately
anticipate and meet the needs of scholarly and educational users.published or submitted for publicatio
Detection of Overlapping Passive Manipulation Techniques in Image Forensics
With a growing number of images uploaded daily to social media sites, it is essential to understand if an image can be used to trace its origin. Forensic investigations are focusing on analyzing images that are uploaded to social media sites resulting in an emphasis on building and validating tools. There has been a strong focus on understanding active manipulation or tampering techniques and building tools for analysis. However, research on manipulation is often studied in a vacuum, involving only one technique at a time. Additionally, less focus has been placed on passive manipulation, which can occur by simply uploading an image to a social media site. This research plots the path of an image through multiple social media sites and identifies unique markers in the metadata that can be used to track the image. Both Facebook and Twitter were utilized on both phone and web applications to fully understand any differences between direct and secondary uploads. A full metadata analysis was conducted including histogram and size comparisons. This paper presents several differences and unique metadata findings that allow image provenance to be traced to an original image. This includes a review of IPTC, ICC, and EXIF metadata, ICC profile and Color Profile Description, Encoding Processes, Estimated Quality Values as well as compression ratios. A checklist of variables is given to guide future evaluations of image provenance
IVOA Recommendation: SAMP - Simple Application Messaging Protocol Version 1.3
SAMP is a messaging protocol that enables astronomy software tools to
interoperate and communicate.
IVOA members have recognised that building a monolithic tool that attempts to
fulfil all the requirements of all users is impractical, and it is a better use
of our limited resources to enable individual tools to work together better.
One element of this is defining common file formats for the exchange of data
between different applications. Another important component is a messaging
system that enables the applications to share data and take advantage of each
other's functionality. SAMP builds on the success of a prior messaging
protocol, PLASTIC, which has been in use since 2006 in over a dozen astronomy
applications and has proven popular with users and developers. It is also
intended to form a framework for more general messaging requirements
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