169 research outputs found
FireFly Mosaic: A Vision-Enabled Wireless Sensor Networking System
Abstract — With the advent of CMOS cameras, it is now possible to make compact, cheap and low-power image sensors capable of on-board image processing. These embedded vision sensors provide a rich new sensing modality enabling new classes of wireless sensor networking applications. In order to build these applications, system designers need to overcome challanges associated with limited bandwith, limited power, group coordination and fusing of multiple camera views with various other sensory inputs. Real-time properties must be upheld if multiple vision sensors are to process data, com-municate with each other and make a group decision before the measured environmental feature changes. In this paper, we present FireFly Mosaic, a wireless sensor network image processing framework with operating system, networking and image processing primitives that assist in the development of distributed vision-sensing tasks. Each FireFly Mosaic wireless camera consists of a FireFly [1] node coupled with a CMUcam3 [2] embedded vision processor. The FireFly nodes run the Nano-RK [3] real-time operating system and communicate using the RT-Link [4] collision-free TDMA link protocol. Using FireFly Mosaic, we demonstrate an assisted living application capable of fusing multiple cameras with overlapping views to discover and monitor daily activities in a home. Using this application, we show how an integrated platform with support for time synchronization, a collision-free TDMA link layer, an underlying RTOS and an interface to an embedded vision sensor provides a stable framework for distributed real-time vision processing. To the best of our knowledge, this is the first wireless sensor networking system to integrate multiple coordinating cameras performing local processing. I
Flexi-WVSNP-DASH: A Wireless Video Sensor Network Platform for the Internet of Things
abstract: Video capture, storage, and distribution in wireless video sensor networks
(WVSNs) critically depends on the resources of the nodes forming the sensor
networks. In the era of big data, Internet of Things (IoT), and distributed
demand and solutions, there is a need for multi-dimensional data to be part of
the Sensor Network data that is easily accessible and consumable by humanity as
well as machinery. Images and video are expected to become as ubiquitous as is
the scalar data in traditional sensor networks. The inception of video-streaming
over the Internet, heralded a relentless research for effective ways of
distributing video in a scalable and cost effective way. There has been novel
implementation attempts across several network layers. Due to the inherent
complications of backward compatibility and need for standardization across
network layers, there has been a refocused attention to address most of the
video distribution over the application layer. As a result, a few video
streaming solutions over the Hypertext Transfer Protocol (HTTP) have been
proposed. Most notable are Apple’s HTTP Live Streaming (HLS) and the Motion
Picture Experts Groups Dynamic Adaptive Streaming over HTTP (MPEG-DASH). These
frameworks, do not address the typical and future WVSN use cases. A highly
flexible Wireless Video Sensor Network Platform and compatible DASH (WVSNP-DASH)
are introduced. The platform's goal is to usher video as a data element that
can be integrated into traditional and non-Internet networks. A low cost,
scalable node is built from the ground up to be fully compatible with the
Internet of Things Machine to Machine (M2M) concept, as well as the ability to
be easily re-targeted to new applications in a short time. Flexi-WVSNP design
includes a multi-radio node, a middle-ware for sensor operation and
communication, a cross platform client facing data retriever/player framework,
scalable security as well as a cohesive but decoupled hardware and software
design.Dissertation/ThesisDoctoral Dissertation Electrical Engineering 201
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An Opportunistic Service Oriented Approach for Robot Search
Health care for the elderly poses a major challenge as the baby boomer generation ages. Part of the solution is to develop technology using sensor networks and service robotics to increase the length of time that an elder can remain at home. Since moderate immobility and memory impairment are common as people age, a major problem for the elderly is locating and retrieving frequently used common objects such as keys, cellphones, books, etc. However, for robots to assist people while they search for objects, they must possess the ability to interact with the human client, complex client-side environments and heterogeneous sensorimotor resources. Given this complexity, the traditional approach of developing particular control strategies in a top-down manner is not suitable. In this dissertation an opportunistic service-oriented approach is presented to address the robot search problem in residential eldercare. With the presented approach, a hierarchy of search strategies is developed in a bottom-up manner from passive object detection and retrieval performed by embedded camera sensors to context-aware cooperative search performed by a human-robot team. By opportunistically employing available sensorimotor resources, the robotic application achieves increased search performance, and has the flexibility to balance between performance goals and resource constraints. To evaluate the proposed approach, I describe several experiments with a robot-sensor network that includes the UMass uBot-5, Pan-Tilt-Zoom cameras and wireless sensors. The results of these experiments suggest that the robot search application based on the proposed approach can lead to efficient search performance and great flexibility in resource-constrained environments
Coverage problems in mobile sensing
Thesis (Ph. D.)--Massachusetts Institute of Technology, Dept. of Mechanical Engineering, 2008.Includes bibliographical references (p. 177-183).Sensor-networks can today measure physical phenomena at spatial and temporal scales that were not achievable earlier, and have shown promise in monitoring the environment, structures, agricultural fields and so on. A key challenge in sensor-networks is the coordination of four actions across the network: measurement (sensing), communication, motion and computation. The term coverage is applied to the central question of how well a sensor-network senses some phenomenon to make inferences. More formally, a coverage problem involves finding an arrangement of sensors that optimizes a coverage metric. In this thesis we examine coverage in the context of three sensing modalities. The literature on the topic has thus far focused largely on coverage problems with the first modality: static event-detection sensors, which detect purely binary events in their immediate vicinity based on thresholds. However, coverage problems for sensors which measure physical quantities like temperature, pressure, chemical concentrations, light intensity and so on in a network configuration have received limited attention in the literature. We refer to this second modality of sensors as estimation sensors; local estimates from such sensors can be used to reconstruct a field. Third, there has been recent interest in deploying sensors on mobile platforms. Mobility has the effect of increasing the effectiveness of sensing actions. We further classify sensor mobility into incidental and intentional motion. Incidentally mobile sensors move passively under the influence of the environment, for instance, a floating sensor drifting in the sea. We define intentional mobility as the ability to control the location and trajectory of the sensor, for example by mounting it on a mobile robot. We build our analysis on a series of cases. We first analyze coverage and connectivity of a network of floating sensors in rivers using simulations and experimental data, and give guidelines for sensor-network design. Second, we examine intentional mobility and detection sensors.(cont.) We examine the problem of covering indoor and outdoor pathways with reconfigurable camera sensor-networks. We propose and validate an empirical model for detection behavior of cameras. We propose a distributed algorithm for reconfiguring locations of cameras to maximize detection performance. Finally, we examine more general strategies for the placement of estimation sensors and ask when and where to take samples in order to estimate an unknown spatiotemporal field with tolerable estimation errors. We discuss various classes of error-tolerant sensor arrangements for trigonometric polynomial fields.by Ajay A. Deshpande.Ph.D
Analysis of the membrane binding mechanism of Remorins and their role in beneficial endosymbioses
The plasma membrane is highly organized and within the plasma membrane proteins cluster into so-called membrane domains. Remorins are well-established membrane domain marker proteins. However, the general plasma membrane anchoring mechanism of these proteins was so far unknown. Biochemical approaches and localization studies investigating different remorins from Medicago truncatula and Arabidopsis thaliana enabled us to demonstrate that S-acylation (palmitoylation) within a C-terminal plasma membrane anchoring motif mediates tight plasma membrane attachment of these proteins. However, we could show that S-acylation is not the sole driving force for remorin immobilization in membrane nanodomains.
The focus of the second part of this thesis was on the beneficial interaction between plants and symbionts. More than 80% of today´s land plants can undergo an interaction with endosymbiotic fungi that is known as Arbuscular Mycorrhiza (AM). In addition, legume plants have gained the ability to establish a second type of endosymbiosis by interacting with nitrogen-fixing rhizobia: the Root Nodule Symbiosis (RNS). Both interactions are partly controlled by the same pathway, the so-called Common Symbiosis Pathway (CSP) that has evolved through recruitment of signaling components from the evolutionary older AM to the more recently evolved RNS signaling pathway. Depending on the recognition of either fungi or rhizobia downstream of this pathway two morphologically different symbiotic structures are formed within the inner root cortex, either arbuscules or root nodules, respectively.
In parallel to the evolution of RNS a local negative regulatory circuit must have evolved to suppress root nodule organogenesis when both interacting symbionts are present and arbuscule formation takes place. In this study first evidence for such a postulated regulatory pathway is presented based on the characterization of the legume-specific remorin MYCREM, which co-evolved with RNS. Phenotypic studies of mutant plants revealed that in the presence of both symbionts MYCREM functions as a negative regulator with respect to root nodule organogenesis events in a CSP-dependent manner. Analyzing the effect of overexpression of auto-active CSP-signaling components, which are known to spontaneously induce root nodule organogenesis, demonstrated a negative regulatory function of MCYREM as well. In summary, this work could serve as basis for further studies to understand the tripartite interaction of legume plants, fungi and rhizobia, as it is found in nature
Internet of Underwater Things and Big Marine Data Analytics -- A Comprehensive Survey
The Internet of Underwater Things (IoUT) is an emerging communication
ecosystem developed for connecting underwater objects in maritime and
underwater environments. The IoUT technology is intricately linked with
intelligent boats and ships, smart shores and oceans, automatic marine
transportations, positioning and navigation, underwater exploration, disaster
prediction and prevention, as well as with intelligent monitoring and security.
The IoUT has an influence at various scales ranging from a small scientific
observatory, to a midsized harbor, and to covering global oceanic trade. The
network architecture of IoUT is intrinsically heterogeneous and should be
sufficiently resilient to operate in harsh environments. This creates major
challenges in terms of underwater communications, whilst relying on limited
energy resources. Additionally, the volume, velocity, and variety of data
produced by sensors, hydrophones, and cameras in IoUT is enormous, giving rise
to the concept of Big Marine Data (BMD), which has its own processing
challenges. Hence, conventional data processing techniques will falter, and
bespoke Machine Learning (ML) solutions have to be employed for automatically
learning the specific BMD behavior and features facilitating knowledge
extraction and decision support. The motivation of this paper is to
comprehensively survey the IoUT, BMD, and their synthesis. It also aims for
exploring the nexus of BMD with ML. We set out from underwater data collection
and then discuss the family of IoUT data communication techniques with an
emphasis on the state-of-the-art research challenges. We then review the suite
of ML solutions suitable for BMD handling and analytics. We treat the subject
deductively from an educational perspective, critically appraising the material
surveyed.Comment: 54 pages, 11 figures, 19 tables, IEEE Communications Surveys &
Tutorials, peer-reviewed academic journa
Geospatial Web Services, Open Standards, and Advances in Interoperability: A Selected, Annotated Bibliography
This paper is designed to help GIS librarians and information specialists follow developments in the emerging field of geospatial Web services (GWS). When built using open standards, GWS permits users to dynamically access, exchange, deliver, and process geospatial data and products on the World Wide Web, no matter what platform or protocol is used. Standards/specifications pertaining to geospatial ontologies, geospatial Web services and interoperability are discussed in this bibliography. Finally, a selected, annotated list of bibliographic references by experts in the field is presented
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