3,142 research outputs found
Capturing Data Uncertainty in High-Volume Stream Processing
We present the design and development of a data stream system that captures
data uncertainty from data collection to query processing to final result
generation. Our system focuses on data that is naturally modeled as continuous
random variables. For such data, our system employs an approach grounded in
probability and statistical theory to capture data uncertainty and integrates
this approach into high-volume stream processing. The first component of our
system captures uncertainty of raw data streams from sensing devices. Since
such raw streams can be highly noisy and may not carry sufficient information
for query processing, our system employs probabilistic models of the data
generation process and stream-speed inference to transform raw data into a
desired format with an uncertainty metric. The second component captures
uncertainty as data propagates through query operators. To efficiently quantify
result uncertainty of a query operator, we explore a variety of techniques
based on probability and statistical theory to compute the result distribution
at stream speed. We are currently working with a group of scientists to
evaluate our system using traces collected from the domains of (and eventually
in the real systems for) hazardous weather monitoring and object tracking and
monitoring.Comment: CIDR 200
Survey on Lightweight Primitives and Protocols for RFID in Wireless Sensor Networks
The use of radio frequency identification (RFID) technologies is becoming widespread in all kind of wireless network-based applications. As expected, applications based on sensor networks, ad-hoc or mobile ad hoc networks (MANETs) can be highly benefited from the adoption of RFID solutions. There is a strong need to employ lightweight cryptographic primitives for many security applications because of the tight cost and constrained resource requirement of sensor based networks. This paper mainly focuses on the security analysis of lightweight protocols and algorithms proposed for the security of RFID systems. A large number of research solutions have been proposed to implement lightweight cryptographic primitives and protocols in sensor and RFID integration based resource constraint networks. In this work, an overview of the currently discussed lightweight primitives and their attributes has been done. These primitives and protocols have been compared based on gate equivalents (GEs), power, technology, strengths, weaknesses and attacks. Further, an integration of primitives and protocols is compared with the possibilities of their applications in practical scenarios
Building efficient wireless infrastructures for pervasive computing environments
Pervasive computing is an emerging concept that thoroughly brings computing devices and the consequent technology into people\u27s daily life and activities. Most of these computing devices are very small, sometimes even invisible , and often embedded into the objects surrounding people. In addition, these devices usually are not isolated, but networked with each other through wireless channels so that people can easily control and access them. In the architecture of pervasive computing systems, these small and networked computing devices form a wireless infrastructure layer to support various functionalities in the upper application layer.;In practical applications, the wireless infrastructure often plays a role of data provider in a query/reply model, i.e., applications issue a query requesting certain data and the underlying wireless infrastructure is responsible for replying to the query. This dissertation has focused on the most critical issue of efficiency in designing such a wireless infrastructure. In particular, our problem resides in two domains depending on different definitions of efficiency. The first definition is time efficiency, i.e., how quickly a query can be replied. Many applications, especially real-time applications, require prompt response to a query as the consequent operations may be affected by the prior delay. The second definition is energy efficiency which is extremely important for the pervasive computing devices powered by batteries. Above all, our design goal is to reply to a query from applications quickly and with low energy cost.;This dissertation has investigated two representative wireless infrastructures, sensor networks and RFID systems, both of which can serve applications with useful information about the environments. We have comprehensively explored various important and representative problems from both algorithmic and experimental perspectives including efficient network architecture design and efficient protocols for basic queries and complicated data mining queries. The major design challenges of achieving efficiency are the massive amount of data involved in a query and the extremely limited resources and capability each small device possesses. We have proposed novel and efficient solutions with intensive evaluation. Compared to the prior work, this dissertation has identified a few important new problems and the proposed solutions significantly improve the performance in terms of time efficiency and energy efficiency. Our work also provides referrable insights and appropriate methodology to other similar problems in the research community
Optimization of manipulation logistics using data matrix codes
In the paper we deal with optimization of manipulation logistics using Data Matrix codes. Our goal is scanning and decoding Data Matrix codes in real-time. We have designed and verified an efficient computer aided method for location of the Data Matrix codes. This method is also suited to real-time processing and has been verified on a test set of images taken from real industrial world. We have proposed a modified, computationally efficient local thresholding technique that uses local mean and variation under the sliding window. The proposed Data Matrix code localization algorithm utilizes the connecting of the adjoining points into the continuous regions and determining of the boundaries of the outer region and it works in two basic steps: localization of the Finder Pattern and verification of the Timing Pattern. Part of the algorithm deals also with the decoding of the Data Matrix code using external libraries. Data Matrix codes can be used to mark logistic units, parts, warehousing positions, but also for automated robot navigation. Because of their low cost, accuracy, speed, reliability, flexibility and efficiency, as well as the ability to write large amounts of data on a small area, they still have a great advantage in logistics.[KEGA MS SR 003TU Z-4/2016
Backscattering UWB/UHF hybrid solutions for multi-reader multi-tag passive RFID systems
Ultra-wideband (UWB) technology is foreseen as a promising solution to overcome the limits of ultra-high frequency (UHF) techniques toward the development of green radio frequency identification (RFID) systems with low energy consumption and localization capabilities. While UWB techniques have been already employed for active tags, passive tags solutions are more appealing also due to their lower cost. With the fundamental requirement of maintaining backward compatibility in the RFID domain, we propose a hybrid UWB/UHF architecture to improve passive tag identification both in single-reader and multi-reader scenarios. We then develop two hybrid algorithms: the first one exploits the UWB signal to improve ISO/IEC 18000-6C UHF standard, while the other one exploits UWB to enhance a compressive sensing (CS) technique for tag identification in the multi-reader, multi-tag scenario. Both solutions are able to improve success rate and reading speed in the tag identification process and reduce the energy consumption. The multi-reader version of the proposed approaches is based on a cooperative scheme in order to manage reader-tag collisions and reader-reader collisions besides the typical tag-tag collisions. Furthermore, timing synchronization non-idealities are analyzed for the proposed solutions and simulation results reveal the effectiveness of the developed schemes
A review of laser scanning for geological and geotechnical applications in underground mining
Laser scanning can provide timely assessments of mine sites despite adverse
challenges in the operational environment. Although there are several published
articles on laser scanning, there is a need to review them in the context of
underground mining applications. To this end, a holistic review of laser
scanning is presented including progress in 3D scanning systems, data
capture/processing techniques and primary applications in underground mines.
Laser scanning technology has advanced significantly in terms of mobility and
mapping, but there are constraints in coherent and consistent data collection
at certain mines due to feature deficiency, dynamics, and environmental
influences such as dust and water. Studies suggest that laser scanning has
matured over the years for change detection, clearance measurements and
structure mapping applications. However, there is scope for improvements in
lithology identification, surface parameter measurements, logistic tracking and
autonomous navigation. Laser scanning has the potential to provide real-time
solutions but the lack of infrastructure in underground mines for data
transfer, geodetic networking and processing capacity remain limiting factors.
Nevertheless, laser scanners are becoming an integral part of mine automation
thanks to their affordability, accuracy and mobility, which should support
their widespread usage in years to come
Technologies for safe and resilient earthmoving operations: A systematic literature review
Resilience engineering relates to the ability of a system to anticipate, prepare, and respond to predicted and unpredicted disruptions. It necessitates the use of monitoring and object detection technologies to ensure system safety in excavation systems. Given the increased investment and speed of improvement in technologies, it is necessary to review the types of technology available and how they contribute to excavation system safety. A systematic literature review was conducted which identified and classified the existing monitoring and object detection technologies, and introduced essential enablers for reliable and effective monitoring and object detection systems including: 1) the application of multisensory and data fusion approaches, and 2) system-level application of technologies. This study also identified the developed functionalities for accident anticipation, prevention and response to safety hazards during excavation, as well as those that facilitate learning in the system. The existing research gaps and future direction of research have been discussed
Applications of wireless sensor technologies in construction
The construction industry is characterised by a number of problems in crucial
fields such as health, safety and logistics. Since these problems affect the progress of
construction projects, the construction industry has attempted to introduce the use of
innovative information and communication technologies on the construction site. Specific
technologies which find applicability on the construction site are wireless sensors, and
especially radio-frequency identification (RFID) technology. RFID tagging is a
technology capable of tracking items. The technology has been applied on the
construction site for various applications, such as asset tracking. There are many
problems related to health, safety and logistics on the construction site which could be
resolved using RFID technology. In the health and safety field, the problems which exist
are the monitoring of dangerous areas on the construction site, such as large excavation
areas, the collisions between workers and vehicles, between vehicles and equipment and
between vehicles, the detection of hazardous substances on the construction site when the
construction work has been completed and the collection of hazard notifications from
specific areas of the construction site as feedback for the prevention of future accidents.
In the logistics field, the tracking of a material during its delivery on the construction site,
its transportation to specific subcontractors and its future utilisation as well as the
monitoring of the rate of use of materials on the construction site, the checking of the
sequence of steel members and the monitoring of the temperature of porous materials are
issues which can be realised using RFID technology. In order to facilitate the use of
RFID technology for the specific health, safety and logistics problems, a system has been
developed. The operation of this system is based on the combined use of hardware and
software elements. The hardware elements of the developed system are a wireless local
area network, RFID readers and tags. Its software elements are a software development
kit based on which, a number of graphical user interfaces have been created for the
interaction of the users with the REID tags, and Notepad files which store data collected
from REID tags through the graphical user interfaces. Each of the graphical user
interfaces is designed in such a way so that it corresponds to the requirements of the
health, safety or logistics situation in which it is used. The proposed system has been
tested on a simulated construction site by a group of experts and a number of findings
have been produced. Specifically, the testing of the proposed system showed that RFID
technology can connect the different stages which characterise the construction supply
chain. In addition, it showed the capability of the technology to be integrated with
construction processes. The testing of the system also revealed the barriers and the
enablers to the use of RFID technology in the construction industry. An example of such
a barrier is the unwillingness of the people of the construction industry to quit traditional
techniques in favour of a new technology. Enablers which enhance the use of RFID
technology in the construction industry are the lack of complexity which characterises the
operation of RFID tagging and the relatively low cost of RFID tags. In general, RFID
technology is an innovative sensor technology which can help the construction industry
through its asset tracking ability. However, further research should be done on the
improvement of RFID technology on specific characteristics, such as its inability to
provide location coordinates and the resilience of the electromagnetic signal emitted by
the RFID reader when there are metallic objects around the reader
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