2,919 research outputs found
Towards a cloud‑based automated surveillance system using wireless technologies
Cloud Computing can bring multiple benefits for Smart Cities. It permits the easy creation of centralized knowledge bases, thus straightforwardly enabling that multiple embedded systems (such as sensor or control devices) can have a collaborative, shared intelligence. In addition to this, thanks to its vast computing power, complex tasks can be done over low-spec devices just by offloading computation to the cloud, with the additional advantage of saving energy. In this work, cloud’s capabilities are exploited to implement and test a cloud-based surveillance system. Using a shared, 3D symbolic world model, different devices have a complete knowledge of all the elements, people and intruders in a certain open area or inside a building. The implementation of a volumetric, 3D, object-oriented, cloud-based world model (including semantic information) is novel as far as we know. Very simple devices (orange Pi) can send RGBD streams (using kinect cameras) to the cloud, where all the processing is distributed and done thanks to its inherent scalability. A proof-of-concept experiment is done in this paper in a testing lab with multiple cameras connected to the cloud with 802.11ac wireless technology. Our results show that this kind of surveillance system is possible currently, and that trends indicate that it can be improved at a short term to produce high performance vigilance system using low-speed devices. In addition, this proof-of-concept claims that many interesting opportunities and challenges arise, for example, when mobile watch robots and fixed cameras would act as a team for carrying out complex collaborative surveillance strategies.Ministerio de Economía y Competitividad TEC2016-77785-PJunta de Andalucía P12-TIC-130
Groups and frequent visitors shaping the space dynamics
Our research is about a dynamic symbolic space model that
is fed with data from the environment by a set of processing modules that
receive raw data from sensor networks. For the conducted experiments
we have been using data from a WiFi network as it is a widely available
infrastructure in our campus. Here we propose two processing modules
which will provide more information about the spaces described in the
model. The first one tries to implement our human perception of the
usual visitors of a place using two measures, the long term and the short
term tenant level. The second one detects where groups of users emerge,
how many there are and what are their dimensions. Based on this new
perspective of the campus we intend to realize how the presence of people
shapes the dynamics of a space.Fundação para a Ciência e a Tecnologia (FCT
Navigation based on symbolic space models
Existing navigation systems are very appropriate
for car navigation, but lack support for convenient
pedestrian navigation and cannot be used indoors due to
GPS limitations. In addition, the creation and the
maintenance of the required models are costly and time
consuming, and are usually based on proprietary data
structures. In this paper we describe a navigation system
based on a human inspired symbolic space model. We argue
that symbolic space models are much easier to create and to
maintain, and that they can support routing applications
based on self-locating through the recognition of nearby
features. Our symbolic space model is supported by a
federation of servers where the spatial descriptions are
stored, and which provide interfaces for feeding and
querying the model. Local models residing in different
servers may be connected between them, thus contributing
to the system scalability.Fundação para a Ciência e a Tecnologia (FCT
Communication Subsystems for Emerging Wireless Technologies
The paper describes a multi-disciplinary design of modern communication systems. The design starts with the analysis of a system in order to define requirements on its individual components. The design exploits proper models of communication channels to adapt the systems to expected transmission conditions. Input filtering of signals both in the frequency domain and in the spatial domain is ensured by a properly designed antenna. Further signal processing (amplification and further filtering) is done by electronics circuits. Finally, signal processing techniques are applied to yield information about current properties of frequency spectrum and to distribute the transmission over free subcarrier channels
Human mobility analysis by collaborative radio landscape observation
A new method to analyze the spatio-temporal activities of humans based on the symbolic information that can be extracted from a set
of observations of mobile networks taken through smart phones is presented. Specifically, GSM andWiFi network observations collected
by several users are gathered to collaboratively build a symbolic base map of the logical structure of the geography. At the same time a
map of the mobility of each individual is also created from the same set of observations. The Proximity Map is then used to provide some
spatial context to the Individual Mobility Maps. This information is intended to be used for the analysis of transportation efficiency.Fundação para a Ciência e a Tecnologia (FCT
Graph-Based Multi-Label Classification for WiFi Network Traffic Analysis
Network traffic analysis, and specifically anomaly and attack detection, call for sophisticated tools relying on a large number of features. Mathematical modeling is extremely difficult, given the ample variety of traffic patterns and the subtle and varied ways that malicious activity can be carried out in a network. We address this problem by exploiting data-driven modeling and computational intelligence techniques. Sequences of packets captured on the communication medium are considered, along with multi-label metadata. Graph-based modeling of the data are introduced, thus resorting to the powerful GRALG approach based on feature information granulation, identification of a representative alphabet, embedding and genetic optimization. The obtained classifier is evaluated both under accuracy and complexity for two different supervised problems and compared with state-of-the-art algorithms. We show that the proposed preprocessing strategy is able to describe higher level relations between data instances in the input domain, thus allowing the algorithms to suitably reconstruct the structure of the input domain itself. Furthermore, the considered Granular Computing approach is able to extract knowledge on multiple semantic levels, thus effectively describing anomalies as subgraphs-based symbols of the whole network graph, in a specific time interval. Interesting performances can thus be achieved in identifying network traffic patterns, in spite of the complexity of the considered traffic classes
Context for Ubiquitous Data Management
In response to the advance of ubiquitous computing technologies, we believe that for computer systems to be ubiquitous, they must be context-aware. In this paper, we address the impact of context-awareness on ubiquitous data management. To do this, we overview different characteristics of context in order to develop a clear understanding of context, as well as its implications and requirements for context-aware data management. References to recent research activities and applicable techniques are also provided
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