Achieving fast and efficient. many-to-many communication is one of the most complex communication problems, especially in wireless systems. A compact form of many-to-many communication in a distributed system has the ...
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ISBN:
(纸本)9781538639917
Achieving fast and efficient. many-to-many communication is one of the most complex communication problems, especially in wireless systems. A compact form of many-to-many communication in a distributed system has the potential to bring huge benefit to many distributed algorithms and protocols. Many to -many communication can he implemented as a sequential instantiations of a network wide one-to-many communication. One limitation of such an approach is that each individual instance of a one-to-many communication has to be given enough time to propagate through the whole network before the next instance. In addition, there is large overhead in generating the schedule for the sequence of individual one-to-many communications. In this work, we show that many-to-many communication can be more efficiently implemented as many parallel many-to-one communications. In this direction, we first develop an efficient TDMA based many-to-one communication module, and then use it in many-to-many setting. Our approach achieves a minimmn about 20% to 50% improvements on latency (radio-on time) over the state-of-the-art solutions in a 90-node wireless sensor network testbed.
Traditionally, achieving constructive interference (CI) required specialized timekeeping hardware. Recently, the ability and interest to employ CI distributedly at any time using groups of ordinary single antenna wire...
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ISBN:
(纸本)9781509014590
Traditionally, achieving constructive interference (CI) required specialized timekeeping hardware. Recently, the ability and interest to employ CI distributedly at any time using groups of ordinary single antenna wireless sensor nodes have grown. In this paper, we investigate achieving CI on sensor nodes. We consider the commonly employed ieee 802.15.4 wireless standard, which uses a chip frequency of 1 MHz. This means signals need to be synchronized with an error below 0.5 microseconds to allow for CI. Hence, excellent clock synchronization between nodes as well as precise transmission timing are required. We implemented and tested a prototype addressing the implementation challenges of synchronizing the nodes' clocks up to a precision of a few hundred nanoseconds and of timing transmissions as accurately as possible. Our results show that, even after multiple minutes of sleep, our approach is able to achieve CI in over 30% of cases, in scenarios in which any influence from the capture effect can be ruled out. This leads to an increase in a packet's chance of arrival to 30-65%, compared to 0-30% when transmitting with either less synchrony or different data payload. Further, we find that 2 senders generally increase the signal power by 2-3 dB and can double the packet reception ratio of weak links.
In this paper, we introduce PIMAP, an IoT-based system for continuous, real-time patient monitoring that operates in a fully autonomous fashion, i.e. without the need for human intervention. To our knowledge, PIMAP is...
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ISBN:
(纸本)9781665439299
In this paper, we introduce PIMAP, an IoT-based system for continuous, real-time patient monitoring that operates in a fully autonomous fashion, i.e. without the need for human intervention. To our knowledge, PIMAP is the first open system that integrates the basic patient monitoring workflow for continuous and autonomous operation and includes sensed data collection, storage, analysis, and real-time visualization. PIMAP's open design allows it to integrate a variety of sensors (custom and off-the-shelf), analytics, and visualization. Other novel features of PIMAP include its deployment flexibility, i.e., its ability to be deployed in different configurations depending on the specific application needs, setting, and resources, as well as PIMAP's self-profiling and self-tuning capabilities. While PIMAP can be applied to various patient monitoring applications and settings, in this paper we focus on the unsolved problem of preventing pressure injuries.
People counting has many applications in smart buildings. For example, adjusting HVAC systems based on the number of occupants in each room can save a significant amount of energy. In addition, security and safety of ...
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ISBN:
(纸本)9781538639917
People counting has many applications in smart buildings. For example, adjusting HVAC systems based on the number of occupants in each room can save a significant amount of energy. In addition, security and safety of the building can be managed by determining the number and location of occupants. Different technologies and sensing platforms have proposed for accurate and efficient people counting. However, these solutions are expensive, hard to deploy, or privacy invasive. We investigate the possibility of placing an 8 x 8 IR array sensor at the doorways and counting the number of people inside rooms. Our solution is real-time, inexpensive, privacy preserving with much less deployment constraints compared to its competitors. The proposed solution deals with realistic and dynamic changes in the sensing environment by leveraging a combination of Otsu's thresholding and modeling thermal noise distribution. We evaluated our solution via several controlled and uncontrolled real-world environments. The results show an average of 93% accuracy in estimating the number of occupants in rooms.
As the current detection solutions of distributed denial of service attacks (DDoS) need additional infrastructures to handle high aggregate data rates, they are not suitable for sensor networks or the internet of thin...
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ISBN:
(纸本)9781665439299
As the current detection solutions of distributed denial of service attacks (DDoS) need additional infrastructures to handle high aggregate data rates, they are not suitable for sensor networks or the internet of things. Besides, the security architecture of software-defined sensor networks needs to pay attention to the vulnerabilities of both software-defined networks and sensor networks. In this paper, we propose a networka-ware automated machine learning (AutoML) framework, which detects DDoS attacks in software-defined sensor networks. Our framework selects an ideal machine learning algorithm to detect DDoS attacks in network-constrained environments, using the metrics such as variable traffic load, heterogeneous traffic rate, and detection time while preventing over-fitting. Our contributions are two-fold: (i) we first investigate the trade-off between the efficiency of ML algorithms and network/traffic state in the scope of DDoS detection. (ii) we design and implement a software architecture containing open-source network tools, with the deployment of multiple ML algorithms. Lastly, we show that under the denial of service attacks, our framework ensures the traffic packets are still delivered within the network with additional delays.
We consider the group communication maintenance problem between a set of k mobile agents that are tracked by a static sensor network. We develop a scalable deterministic distributed algorithm for maintaining a Steiner...
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ISBN:
(纸本)9781479946181
We consider the group communication maintenance problem between a set of k mobile agents that are tracked by a static sensor network. We develop a scalable deterministic distributed algorithm for maintaining a Steiner tree of the agents so that group communication between them can be provided in the minimum cost possible. The main idea is that our algorithm maintains a virtual tree of mobile agents which can be immediately converted to an actual Steiner tree at all times. Our algorithm achieves the Steiner tree with total length at most O(log k) times the length of the minimum Steiner tree in the constant-doubling graph model. The total communication cost (messages) to maintain the Steiner tree is only O(min{log n, logD}) times the optimal communication cost, where n and D, respectively, are the number of nodes and the diameter of the network. We also develop improved algorithms for the k-center, sparse aggregation, and distributed matching problems. Experimental evaluation results show the benefits of our algorithms compared to previous algorithms. These four problems are NP-hard and, to the best of our knowledge, our algorithms are the first near-optimal deterministic algorithms for maintaining approximate solutions to these problems with low maintenance costs in a distributed setting.
With the reduction in size and cost of sensor nodes, dense sensor networks are becoming more popular in a wide-range of applications. Many such applications with dense deployments are geared towards finding various pa...
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ISBN:
(纸本)9781479946181
With the reduction in size and cost of sensor nodes, dense sensor networks are becoming more popular in a wide-range of applications. Many such applications with dense deployments are geared towards finding various patterns or features such as peaks, boundaries and shapes in the spread of sensed physical quantities over an area. However, collecting all the data from individual sensor nodes can be impractical both in terms of timing requirements and the overall resource consumption. Hence, it is imperative to devise distributed information processing techniques that can help in identifying such features with a high accuracy and within certain time constraints. In this paper, we exploit the prioritized channel-access mechanism of dominance-based Medium Access Control (MAC) protocols to efficiently obtain exterma of the sensed quantities. We show how by the use of simple transforms that sensor nodes employ on local data it is also possible to efficiently extract certain features such as local extrema and boundaries of events. Using these transformations, we show through extensive evaluations that our proposed technique is fast and efficient at retrieving only sensor data point with the most constructive information, independent of the number of sensor nodes in the network.
Today, camera networks are pervasively used in smart environments such as intelligent homes, industrial automation or surveillance. These applications often require cameras to be aware of their spatial neighbors or ev...
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ISBN:
(纸本)9781728105703
Today, camera networks are pervasively used in smart environments such as intelligent homes, industrial automation or surveillance. These applications often require cameras to be aware of their spatial neighbors or even to operate on a common ground plane. A major concern in the use of sensor networks in general is their robustness and reliability even in the presence of attackers. This paper addresses the challenge of detecting malicious nodes during the calibration phase of camera networks. Such a resilient calibration enables robust and reliable localization results and the elimination of attackers right after the network deployment. Specifically, we consider the problem of identifying subverted nodes which manipulate calibration data and can not be detected by standard cryptographic methods. The experiments in our network show that our self-calibration algorithm enables location-unknown cameras to successfully detect malicious nodes while autonomously calibrating the network.
In this paper, we focus on designing a holistic approach to gather, monitor and analyze heterogeneous sources on allergies and allergens into one system. The dimensions of mobile crowdsensing, the sensor-based measure...
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ISBN:
(纸本)9781728105703
In this paper, we focus on designing a holistic approach to gather, monitor and analyze heterogeneous sources on allergies and allergens into one system. The dimensions of mobile crowdsensing, the sensor-based measurements, and micro-blogging raw texts are combined to address all different situations and needs. We envision that our system can be used for public health monitoring in order to early predict allergy/allergens or allergy-related irritants outbreaks. To the best of our knowledge, our system is the first holistic approach of a surveillance system for allergy in the US region.
Cyber-physical swarms represent a paradigm shift in distributedsystems, mirroring characteristics akin to natural swarms, such as self-organization, scalability, and fault tolerance. This paper delves into these comp...
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ISBN:
(纸本)9798350369458;9798350369441
Cyber-physical swarms represent a paradigm shift in distributedsystems, mirroring characteristics akin to natural swarms, such as self-organization, scalability, and fault tolerance. This paper delves into these complex systems, characterized by vast networks of cyber-physical entities with limited environmental awareness, yet capable of exhibiting emergent collective behaviors. These systems encompass a diverse array of scenarios, ranging from swarm robotics to the interconnectivity in smart cities, as well as the collaboration among augmented humans. The engineering of such systems presents unique challenges, primarily due to their intricate complexity and the spontaneous nature of their collective behaviors. This paper aims to dissect these challenges, offering a clear delineation of potential approaches. We present a comprehensive analysis, shedding light on the intricacies of engineering cyberphysical swarms and discussing modern solutions in engineering collective applications for such systems.
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