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The proliferation of the Internet of Things hinges on the successful internetworking of billions of devices. While many approaches advocate for building on a thus-far versatile Internet infrastructure, many faltering claims for scalability will hinder IoT operation and responsiveness. At the heart of the problem, IoT is largely disparate in operational mandates, communication technologies, and access...
The rising tide of data from Sensor Networks, Internet of Things devices and novel sensing systems (e.g. smart devices and wearable technology) are introducing a number of opportunities as well as challenges. While the diversity and abundance of sensing resources are providing a wealth of data for Information Services, we are facing growing challenges in coping with the volume, diversity, and inconsistency...
The growing demand for video streaming is straining the current Internet, and mandating a novel approach to future Internet paradigms. The advent of Information-Centric Networks (ICN) promises a novel architecture for addressing this exponential growth in data traffic, with ubiquitous caching to facilitate video delivery. In this paper, we present a novel in-network video caching policy in ICN, named...
This paper examines a shortcoming of the classical phasor diagram of a salient-pole synchronous machine based on the well-established two-reaction theory. Unlike in the phasor diagram of a smooth-air-gap machine, it is not possible to readily identify the internally-developed electromagnetic power of a salient-pole synchronous machine from this phasor diagram. By defining new machine reactances, a...
This work presents an offline standstill identification technique, where the synchronous machine is locked at an arbitrary (but known) angle, and a test is conducted over a short period of time. In contrast to the well-known standard Standstill Frequency Response (SSFR) technique, which could take more than 6 hours to conduct, the method proposed here collects all the required data in few seconds...
This work presents a standstill (offline) parameter identification method for synchronous machines with dual field excitation on the d and q axes of the rotor. Such machines have applications as turbogenerators and synchronous motors. One machine with an equivalent model is the divided winding rotor synchronous generator, which is a round rotor machine that was proposed by Soper and Fagg. A methodology...
Much has been deliberated lately on the adaptability of Wireless Sensor Networks (WSNs) to transition into a Cloud-based paradigm. This divergence has been mainly attributed to enabling a dynamic design, larger spread and a more distributed control scheme for WSNs that are inherently static and data-centric. Thus, transitioning into a service-centric paradigm, with the “Cloud” as an enabler, seems...
An important mandate for the operation of Wireless Sensor Networks (WSNs) is ensuring resilient operation. While current solutions, such as over-deployment, ruggedized packaging and re-mobilization of sensing nodes, offer viable remedies, the question of resilience lies beyond sheer functionality with fault tolerance. That is, a trade-off has commonly grown to be a myth, we could either have a resilient...
The abundance of sensed data and its correlation between wireless entities has recently increased significantly. Understanding the context of each entity in a given environment is not-trivial. Mainly due to the need of realizing an efficient scheme for context fusion over multiple sensing/polling technologies. In this paper we present a selective context fusion model that utilizes an integrated architecture...
Recent research endeavours are capitalizing on state of the art technologies to build a scalable Internet of Things (IoT). Envisioned as a technology to integrate the best of Wireless Sensor Networks and RFID systems, there is much promise for a global network of objects that are identifiable, track-able, and harmoniously informing. However, the realization of an IoT framework is hindered by many...
RFID-Sensor Networks (RSNs) represent the pervasive components of the heterogeneous Internet of Things (IoT) paradigm. By incorporating both the identification and localization capabilities of Radio Frequency Identification (RFID) and the sensing and inter-communication of Wireless sensor networks (WSNs), RSNs are capable of realizing the IoT on a global scale. A pressing hindrance to cost-effectiveness...
In a technology where multiple networks are often deployed in concurrency, significant resource underutilization is witnessed in Wireless Sensor Networks (WSNs). As the manufacturing and deployment costs drop, multiple networks are introduced in overlapping vicinities to satisfy new functional requirements. Mostly with dedicated goals and deterministic operation schemes, practitioners seldom investigate...
The Internet of Things (IoT) is envisioned as a paradigm shift, with a plethora of applications, on the premise of well-established enabling technologies; prominently Wireless Sensor Networks (WSNs) and RFIDs. The former has evolved to improve energy efficiency and resilient operation, yet true scalability has only been recently probed and quite sparsely advanced. Moreover, the traditional approach,...
Today's abundance of sensors and their wireless/wired networks, coupled with a growing plethora of applications, necessitate a dynamic approach to the assignment of tasks to a network. The current practice in WSN design is almost always application specific, due to functional and resource tradeoffs that have justified much of the tailored research done so far. Identifying this as a major bottleneck...
Tag collisions impose a significant hindrance to reading rates of Radio Frequency Identification systems. The parallel singulation approach, being a major milestone, clusters tags and autonomously interrogates each cluster in parallel. This technique reduces the number of tags being interrogated at a given time, reducing collisions, and achieves higher reading rates. However, such an approach faces...
The induction machine is widely utilized in the industry and exists in a plethora of applications. Although it is characterized by its inherent stability over a wide range of operating conditions, this characterization is based on steady-state arguments. This work develops a rigorous approach to the open-loop stability of the induction machine. In particular, a condition for the global asymptotic...
Indirect field oriented control of an induction machine requires knowledge of the rotor time constant to estimate the rotor flux linkages. An online method is described for estimating the rotor time constant and the stator resistance both of which vary during operation of the machine due to ohmic heating. The method formulates the problem using a nonlinear least-squares criterion and is guaranteed...
The paper deals with the control of a bioreactor. Three sliding mode control schemes are proposed for the bioreactor benchmark problem. The first two controllers are static sliding mode controllers; the third controller is a dynamic sliding mode controller. The three controllers guarantee the asymptotic convergence of the states of the system to their desired values. Simulation results are given to...
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