49,085 research outputs found
When Things Matter: A Data-Centric View of the Internet of Things
With the recent advances in radio-frequency identification (RFID), low-cost
wireless sensor devices, and Web technologies, the Internet of Things (IoT)
approach has gained momentum in connecting everyday objects to the Internet and
facilitating machine-to-human and machine-to-machine communication with the
physical world. While IoT offers the capability to connect and integrate both
digital and physical entities, enabling a whole new class of applications and
services, several significant challenges need to be addressed before these
applications and services can be fully realized. A fundamental challenge
centers around managing IoT data, typically produced in dynamic and volatile
environments, which is not only extremely large in scale and volume, but also
noisy, and continuous. This article surveys the main techniques and
state-of-the-art research efforts in IoT from data-centric perspectives,
including data stream processing, data storage models, complex event
processing, and searching in IoT. Open research issues for IoT data management
are also discussed
Autonomous real-time surveillance system with distributed IP cameras
An autonomous Internet Protocol (IP) camera based object tracking and behaviour identification system, capable of running in real-time on an embedded system with limited memory and processing power is presented in this paper. The main contribution of this work is the integration of processor intensive image processing algorithms on an embedded platform capable of running at real-time for monitoring the behaviour of pedestrians. The Algorithm Based Object Recognition and Tracking (ABORAT) system architecture presented here was developed on an Intel PXA270-based development board clocked at 520 MHz. The platform was connected to a commercial stationary IP-based camera in a remote monitoring station for intelligent image
processing. The system is capable of detecting moving objects and their shadows in a complex environment with varying lighting intensity and moving foliage. Objects
moving close to each other are also detected to extract their trajectories which are then fed into an unsupervised neural network for autonomous classification. The novel intelligent video system presented is also capable of performing simple analytic functions such as tracking and generating alerts when objects enter/leave regions or cross tripwires superimposed on live video by the operator
iCrawl: Improving the Freshness of Web Collections by Integrating Social Web and Focused Web Crawling
Researchers in the Digital Humanities and journalists need to monitor,
collect and analyze fresh online content regarding current events such as the
Ebola outbreak or the Ukraine crisis on demand. However, existing focused
crawling approaches only consider topical aspects while ignoring temporal
aspects and therefore cannot achieve thematically coherent and fresh Web
collections. Especially Social Media provide a rich source of fresh content,
which is not used by state-of-the-art focused crawlers. In this paper we
address the issues of enabling the collection of fresh and relevant Web and
Social Web content for a topic of interest through seamless integration of Web
and Social Media in a novel integrated focused crawler. The crawler collects
Web and Social Media content in a single system and exploits the stream of
fresh Social Media content for guiding the crawler.Comment: Published in the Proceedings of the 15th ACM/IEEE-CS Joint Conference
on Digital Libraries 201
The S2 VLBI Correlator: A Correlator for Space VLBI and Geodetic Signal Processing
We describe the design of a correlator system for ground and space-based
VLBI. The correlator contains unique signal processing functions: flexible LO
frequency switching for bandwidth synthesis; 1 ms dump intervals, multi-rate
digital signal-processing techniques to allow correlation of signals at
different sample rates; and a digital filter for very high resolution
cross-power spectra. It also includes autocorrelation, tone extraction, pulsar
gating, signal-statistics accumulation.Comment: 44 pages, 13 figure
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