Método de detección fallas para sistemas solares fotovoltaicos conectados a micro-redes en AC usando un observador por modo deslizante

La presente investigación desarrolla un método de detección de fallos para sistemas solares fotovoltaicos conectados a Micro-redes Híbridas. El método planteado se basa en un modelo por observabilidad de modo deslizante, este método permite desarrollar la detección de fallas en sistemas no lineales que están expuesto a fallos. El estudio permite obtener los parámetros de diseño del observador y del sistema de detección de fallas. La investigación se implementó en un Micro-Red Híbrida tipo benchmark con funcionalidad normal y con la incorporación de fallas en el control primario del sistema solar fotovoltaico, tanto para la corriente como para el voltaje. Los resultados obtenidos fueron simulados y comparados antes diversos escenarios de fallas. La observancia de las salidas dinámicas del sistema (V y I) siendo el caso base el de operación normal, estos escenarios fueron simulados mediante el paquete informático Matlab/Simulink validando así el método de detección a fallas.This research develops a fault detection method for solar photovoltaic (PV) systems connected to a Hybrid Micro Grid (HMG). The proposed method is based on a Sliding Mode Observer (SMO) model. This method allows the development of fault detection in nonlinear systems that are exposed to failures. The study allows to obtain the design parameters of the observer and of the fault detection system. The research was implemented in a benchmark HMG with normal operation and with the incorporation of faults in the primary control of PVs for both current and voltage. The results obtained were simulated and compared before different fault scenarios by observing the dynamic outputs of the system (V and I) being the base case the normal operation, these scenarios were simulated using the Matlab/Simulink software package, thus validating the fault detection method

Contextual biometric watermarking of fingerprint images

This research presents contextual digital watermarking techniques using face and demographic text data as multiple watermarks for protecting the evidentiary integrity of fingerprint image. The proposed techniques embed the watermarks into selected regions of fingerprint image in MDCT and DWT domains. A general image watermarking algorithm is developed to investigate the application of MDCT in the elimination of blocking artifacts. The application of MDCT has improved the performance of the watermarking technique compared to DCT. Experimental results show that modifications to fingerprint image are visually imperceptible and maintain the minutiae detail. The integrity of the fingerprint image is verified through high matching score obtained from the AFIS system. There is also a high degree of correlation between the embedded and extracted watermarks. The degree of similarity is computed using pixel-based metrics and human visual system metrics. It is useful for personal identification and establishing digital chain of custody. The results also show that the proposed watermarking technique is resilient to common image modifications that occur during electronic fingerprint transmission

A control theoretic approach for security of cyber-physical systems

In this dissertation, several novel defense methodologies for cyber-physical systems have been proposed. First, a special type of cyber-physical system, the RFID system, is considered for which a lightweight mutual authentication and ownership management protocol is proposed in order to protect the data confidentiality and integrity. Then considering the fact that the protection of the data confidentiality and integrity is insufficient to guarantee the security in cyber-physical systems, we turn to the development of a general framework for developing security schemes for cyber-physical systems wherein the cyber system states affect the physical system and vice versa. After that, we apply this general framework by selecting the traffic flow as the cyber system state and a novel attack detection scheme that is capable of capturing the abnormality in the traffic flow in those communication links due to a class of attacks has been proposed. On the other hand, an attack detection scheme that is capable of detecting both sensor and actuator attacks is proposed for the physical system in the presence of network induced delays and packet losses. Next, an attack detection scheme is proposed when the network parameters are unknown by using an optimal Q-learning approach. Finally, this attack detection and accommodation scheme has been further extended to the case where the network is modeled as a nonlinear system with unknown system dynamics --Abstract, page iv

Faster than a speeding bullet, more powerful than a locomotive, able to rule by sense of smell! Superhuman Kingship in the Prophetic Books

An exploration of the Hebrew Bible's prophetic literature vis-à-vis Science Fiction and Science Fiction theor

Advanced Fault Diagnosis and Health Monitoring Techniques for Complex Engineering Systems

Over the last few decades, the field of fault diagnostics and structural health management has been experiencing rapid developments. The reliability, availability, and safety of engineering systems can be significantly improved by implementing multifaceted strategies of in situ diagnostics and prognostics. With the development of intelligence algorithms, smart sensors, and advanced data collection and modeling techniques, this challenging research area has been receiving ever-increasing attention in both fundamental research and engineering applications. This has been strongly supported by the extensive applications ranging from aerospace, automotive, transport, manufacturing, and processing industries to defense and infrastructure industries

Communicating the Unspeakable: Linguistic Phenomena in the Psychedelic Sphere

Psychedelics can enable a broad and paradoxical spectrum of linguistic phenomena from the unspeakability of mystical experience to the eloquence of the songs of the shaman or curandera. Interior dialogues with the Other, whether framed as the voice of the Logos, an alien download, or communion with ancestors and spirits, are relatively common. Sentient visual languages are encountered, their forms unrelated to the representation of speech in natural language writing systems. This thesis constructs a theoretical model of linguistic phenomena encountered in the psychedelic sphere for the field of altered states of consciousness research (ASCR). The model is developed from a neurophenomenological perspective, especially the work of Francisco Varela, and Michael Winkelman’s work in shamanistic ASC, which in turn builds on the biogenetic structuralism of Charles Laughlin, John McManus, and Eugene d’Aquili. Neurophenomenology relates the physical and functional organization of the brain to the subjective reports of lived experience in altered states as mutually informative, without reducing consciousness to one or the other. Consciousness is seen as a dynamic multistate process of the recursive interaction of biology and culture, thereby navigating the traditional dichotomies of objective/subjective, body/mind, and inner/outer realities that problematically characterize much of the discourse in consciousness studies. The theoretical work of Renaissance scholar Stephen Farmer on the evolution of syncretic and correlative systems and their relation to neurobiological structures provides a further framework for the exegesis of the descriptions of linguistic phenomena in first-person texts of long-term psychedelic selfexploration. Since the classification of most psychedelics as Schedule I drugs, legal research came to a halt; self-experimentation as research did not. Scientists such as Timothy Leary and John Lilly became outlaw scientists, a social aspect of the “unspeakability” of these experiences. Academic ASCR has largely side-stepped examination of the extensive literature of psychedelic selfexploration. This thesis examines aspects of both form and content from these works, focusing on those that treat linguistic phenomena, and asking what these linguistic experiences can tell us about how the psychedelic landscape is constructed, how it can be navigated, interpreted, and communicated within its own experiential field, and communicated about to make the data accessible to inter-subjective comparison and validation. The methodological core of this practice-based research is a technoetic practice as defined by artist and theoretician Roy Ascott: the exploration of consciousness through interactive, artistic, and psychoactive technologies. The iterative process of psychedelic self-exploration and creation of interactive software defines my own technoetic practice and is the means by which I examine my states of consciousness employing the multidimensional visual language Glide

Positioning of a wireless relay node for useful cooperative communication

Given the exorbitant amount of data transmitted and the increasing demand for data connectivity in the 21st century, it has become imperative to search for pro-active and sustainable solutions to the effectively alleviate the overwhelming burden imposed on wireless networks. In this study a Decode and Forward cooperative relay channel is analyzed, with the employment of Maximal Ratio Combining at the destination node as the method of offering diversity combining. The system framework used is based on a three-node relay channel with a source node, relay node and a destination node. A model for the wireless communications channel is formulated in order for simulation to be carried out to investigate the impact on performance of relaying on a node placed at the edge of cell. Firstly, an AWGN channel is used before the effect of Rayleigh fading is taken into consideration. Result shows that performance of cooperative relaying performance is always superior or similar to conventional relaying. Additionally, relaying is beneficial when the relay is placed closer to the receiver

A survey of timing channels and countermeasures

A timing channel is a communication channel that can transfer information to a receiver/decoder by modulating the timing behavior of an entity. Examples of this entity include the interpacket delays of a packet stream, the reordering packets in a packet stream, or the resource access time of a cryptographic module. Advances in the information and coding theory and the availability of high-performance computing systems interconnected by high-speed networks have spurred interest in and development of various types of timing channels. With the emergence of complex timing channels, novel detection and prevention techniques are also being developed to counter them. In this article, we provide a detailed survey of timing channels broadly categorized into network timing channel, in which communicating entities are connected by a network, and in-system timing channel, in which the communicating entities are within a computing system. This survey builds on the last comprehensive survey by Zander et al. [2007] and considers all three canonical applications of timing channels, namely, covert communication, timing side channel, and network flow watermarking. We survey the theoretical foundations, the implementation, and the various detection and prevention techniques that have been reported in literature. Based on the analysis of the current literature, we discuss potential future research directions both in the design and application of timing channels and their detection and prevention techniques

Sensors Fault Diagnosis Trends and Applications

Fault diagnosis has always been a concern for industry. In general, diagnosis in complex systems requires the acquisition of information from sensors and the processing and extracting of required features for the classification or identification of faults. Therefore, fault diagnosis of sensors is clearly important as faulty information from a sensor may lead to misleading conclusions about the whole system. As engineering systems grow in size and complexity, it becomes more and more important to diagnose faulty behavior before it can lead to total failure. In the light of above issues, this book is dedicated to trends and applications in modern-sensor fault diagnosis

Measurements, Models, Systems and Design

531 s.