Design and Implementation of Secure Chaotic Communication Systems

Chaotic systems have properties such as ergodicity, sensitivity to initial conditions/parameter mismatches, mixing property, deterministic dynamics, structure complexity, to mention a few, that map nicely with cryptographic requirements such as confusion, diffusion, deterministic pseudorandomness, algorithm complexity. Furthermore, the possibility of chaotic synchronization, where the master system (transmitter) is driving the slave system (receiver) by its output signal, made it probable for the possible utilization of chaotic systems to implement security in the communication systems. Many methods like chaotic masking, chaotic modulation, inclusion, chaotic shift keying (CSK) had been proposed however, many attack methods later showed them to be insecure. Different modifications of these methods also exist in the literature to improve the security, but almost all suffer from the same drawback. Therefore, the implementation of chaotic systems in security still remains a challenge. In this work, different possibilities on how it might be possible to improve the security of the existing methods are explored. The main problem with the existing methods is that the message imprint could be found in the dynamics of the transmitted signal, therefore by some signal processing or pattern classification techniques, etc, allow the exposition of the hidden message. Therefore, the challenge is to remove any pattern or change in dynamics that the message might bring in the transmitted signal

Design and implementation of secure chaotic communication systems

Chaotic systems have properties such as ergodicity, sensitivity to initial conditions/parameter mismatches, mixing property, deterministic dynamics, structure complexity, to mention a few, that map nicely with cryptographic requirements such as confusion, diffusion, deterministic pseudorandomness, algorithm complexity. Furthermore, the possibility of chaotic synchronization, where the master system (transmitter) is driving the slave system (receiver) by its output signal, made it probable for the possible utilization of chaotic systems to implement security in the communication systems. Many methods like chaotic masking, chaotic modulation, inclusion, chaotic shift keying (CSK) had been proposed however, many attack methods later showed them to be insecure. Different modifications of these methods also exist in the literature to improve the security, but almost all suffer from the same drawback. Therefore, the implementation of chaotic systems in security still remains a challenge. In this work, different possibilities on how it might be possible to improve the security of the existing methods are explored. The main problem with the existing methods is that the message imprint could be found in the dynamics of the transmitted signal, therefore by some signal processing or pattern classification techniques, etc, allow the exposition of the hidden message. Therefore, the challenge is to remove any pattern or change in dynamics that the message might bring in the transmitted signal.EThOS - Electronic Theses Online ServiceGBUnited Kingdo

Advanced Mathematics and Computational Applications in Control Systems Engineering

Control system engineering is a multidisciplinary discipline that applies automatic control theory to design systems with desired behaviors in control environments. Automatic control theory has played a vital role in the advancement of engineering and science. It has become an essential and integral part of modern industrial and manufacturing processes. Today, the requirements for control precision have increased, and real systems have become more complex. In control engineering and all other engineering disciplines, the impact of advanced mathematical and computational methods is rapidly increasing. Advanced mathematical methods are needed because real-world control systems need to comply with several conditions related to product quality and safety constraints that have to be taken into account in the problem formulation. Conversely, the increment in mathematical complexity has an impact on the computational aspects related to numerical simulation and practical implementation of the algorithms, where a balance must also be maintained between implementation costs and the performance of the control system. This book is a comprehensive set of articles reflecting recent advances in developing and applying advanced mathematics and computational applications in control system engineering

Use of automated coding methods to assess motivational behaviour in education

Teachers’ motivational behaviour is related to important student outcomes. Assessing teachers’ motivational behaviour has been helpful to improve teaching quality and enhance student outcomes. However, researchers in educational psychology have relied on self-report or observer ratings. These methods face limitations on accurately and reliably assessing teachers’ motivational behaviour; thus restricting the pace and scale of conducting research. One potential method to overcome these restrictions is automated coding methods. These methods are capable of analysing behaviour at a large scale with less time and at low costs. In this thesis, I conducted three studies to examine the applications of an automated coding method to assess teacher motivational behaviours. First, I systematically reviewed the applications of automated coding methods used to analyse helping professionals’ interpersonal interactions using their verbal behaviour. The findings showed that automated coding methods were used in psychotherapy to predict the codes of a well-developed behavioural coding measure, in medical settings to predict conversation patterns or topics, and in education to predict simple concepts, such as the number of open/closed questions or class activity type (e.g., group work or teacher lecturing). In certain circumstances, these models achieved near human level performance. However, few studies adhered to best-practice machine learning guidelines. Second, I developed a dictionary of teachers’ motivational phrases and used it to automatically assess teachers’ motivating and de-motivating behaviours. Results showed that the dictionary ratings of teacher need support achieved a strong correlation with observer ratings of need support (rfull dictionary = .73). Third, I developed a classification of teachers’ motivational behaviour that would enable more advanced automated coding of teacher behaviours at each utterance level. In this study, I created a classification that includes 57 teacher motivating and de-motivating behaviours that are consistent with self-determination theory. Automatically assessing teachers’ motivational behaviour with automatic coding methods can provide accurate, fast pace, and large scale analysis of teacher motivational behaviour. This could allow for immediate feedback and also development of theoretical frameworks. The findings in this thesis can lead to the improvement of student motivation and other consequent student outcomes

Designing and Composing for Interdependent Collaborative Performance with Physics-Based Virtual Instruments

Interdependent collaboration is a system of live musical performance in which performers can directly manipulate each other’s musical outcomes. While most collaborative musical systems implement electronic communication channels between players that allow for parameter mappings, remote transmissions of actions and intentions, or exchanges of musical fragments, they interrupt the energy continuum between gesture and sound, breaking our cognitive representation of gesture to sound dynamics. Physics-based virtual instruments allow for acoustically and physically plausible behaviors that are related to (and can be extended beyond) our experience of the physical world. They inherently maintain and respect a representation of the gesture to sound energy continuum. This research explores the design and implementation of custom physics-based virtual instruments for realtime interdependent collaborative performance. It leverages the inherently physically plausible behaviors of physics-based models to create dynamic, nuanced, and expressive interconnections between performers. Design considerations, criteria, and frameworks are distilled from the literature in order to develop three new physics-based virtual instruments and associated compositions intended for dissemination and live performance by the electronic music and instrumental music communities. Conceptual, technical, and artistic details and challenges are described, and reflections and evaluations by the composer-designer and performers are documented

Power Converters in Power Electronics

In recent years, power converters have played an important role in power electronics technology for different applications, such as renewable energy systems, electric vehicles, pulsed power generation, and biomedical sciences. Power converters, in the realm of power electronics, are becoming essential for generating electrical power energy in various ways. This Special Issue focuses on the development of novel power converter topologies in power electronics. The topics of interest include, but are not limited to: Z-source converters; multilevel power converter topologies; switched-capacitor-based power converters; power converters for battery management systems; power converters in wireless power transfer techniques; the reliability of power conversion systems; and modulation techniques for advanced power converters

Terrorism's Communicative Dynamic: Leveraging the Terrorist-Audience Relationship to Assess Evolutionary Trajectories

Terrorist groups do not operate in isolation. To survive in the face of counter-pressures from their opponents, the group must establish a beneficial relationship with a targeted audience, a presumed constituency, in order to generate the sympathy and support necessary for maintaining operational viability. Existing studies of terrorism, however, offer few insights into how this might be done. The most common approach revolves around assessments of terrorist messages, yet typically treats those messages as self-serving propaganda or media manipulation. This study takes a different approach, suggesting that terrorists use statements and communiqués in an effort to gain and maintain a supportive audience. Further, the intended audience for the messages infer meaning in terrorist violence, thus augmenting or reducing the impact of persuasive messaging by the terrorist. Understanding this process, in turn, may yield new insights into the dynamic processes of terrorism, offering new opportunities to assess a terrorist group's potential for positive evolutionary growth or greater relative fitness. Using Grunig's situational theory of publics, this study creates and evaluates a new metric, called expected affinity, for examining the terrorist group's effort to establish and strengthen bonds between itself and its targeted and presumptively supportive audience. Expected affinity combines sub-measures addressing problem recognition, expected and desired levels of involvement, and constraint recognition, coupled with an inferred meaning in the symbolism of violent acts in order to evaluate terrorist messages and attacks. The results suggest utility in the expected affinity metric and point to opportunities for making the measure more directly applicable to specific cases through incorporation of detailed case study data

Family Dyads, Emotional Labor, And The Theater Of The Clinical Encounter: Co-Constructive Patient Simulation As A Reflective Tool In Child And Adolescent Psychiatry Training

Patient simulation has been used in medical education to provide a safe and supportive learning environment for learners to practice clinical and interpersonal skills. However, simulation involving pediatric medicine and child psychiatry is rare and generally does not reflect the child-caregiver dyad or the longitudinal aspects of this care and does not provide learners an opportunity to engage with and reflect on these dynamics. We organized a series of 7 observed patient simulation sessions with a cohort of 7 senior child and adolescent psychiatry fellows as an educational opportunity. In these sessions, we utilized the previously described co-constructive patient simulation model to create the simulation cases. We included the use of at least two patient actors in almost all sessions, and two of the case narratives were longitudinally followed across multiple simulation sessions. We conducted a thematic analysis of the data collected from the debriefing sessions after each simulation case via a symbolic interactionist approach. Using the data from the debriefing sessions, I first analyzed the reflections on the simulation experience via a dramaturgical perspective. I then developed the following themes based on a symbolic interactionist approach to the debriefing data: (1) centering the child, allying with the parent, and treating the family system, (2) reflecting on dyadic challenges: role reversal and individuation, (3) ambivalence in and about the parent-child dyad, (4) accepting uncertainty and the unknown and focusing on the here and now, and (5) longitudinal narratives and changing contexts. The depth of participant reflections during the debriefing sessions suggested the emotional authenticity and interpersonal complexity of the simulation cases. The emotional experience of the simulations, for interviews and observers alike, provided an opportunity to reflect on personal and professional experiences and triggered meaningful insights and connections between participants. I then examined the questions of whether we truly simulated the parent-child dyad and whether we truly created a safe space. I explored how CCPS reproduces emotional authenticity and emotional labor. In discussing emotional authenticity, I interrogated the concept of “authenticity” further, explored authentic performance via Stanislavski’s system, and examined how Medical Education Empowered by Theater (MEET) harnesses the power of performance to create emotionally authentic experiences that lead to personal and professional growth. In discussing emotional labor, I turned to Hochschild’s The Managed Heart and complicated the notion of emotional labor in child and adolescent psychiatry. I then examined dyadic relationships as holding environments. I outlined Winnicott’s conceptualization of the mother-infant dyad as the first holding environment and how therapeutic dyads can function as holding environments. I then considered the debriefing session as a holding environment between learners and for the instructor-learner dyad