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The development of Smart Grid and an increased emphasis on Wide Area Measurement, Automation, Protection and Control (WAMPAC) has lead to the substantial increase in the development and use of Synchrophasor Systems. The Department of Energy having realized its importance in the Power System has encouraged its deployment through the Smart Grid Investment Grant. With many utilities beginning to implement a large number of PMUs over their respective power systems, Phasor Data Concentrators (PDCs) play a crucial part in accurately relaying data from the point of measurement to the operators at the control center. The current Synchrophasor standard, IEEE C37.118-2005 covers adequately the steady state characterization of PMUs but does not specify requirements for PDCs. Having recognized the need for such a standard for PDCs, the North American Synchrophasor Initiative (NASPI) has developed a guide outlining some of its objectives, functions and tests requirements. Virginia Tech has developed a PDC Test System under these guidelines and as per the requirements of the PJM Synchrophasor Systems Deployment Project. This thesis focuses on the testing tools developed and the procedures implemented in the Virginia Tech PDC Test System. / Master of Science

Full-motion driving simulators require efficient real-time high fidelity vehicle models in order to provide a more realistic vehicle response. Typically, multi-body models are used to represent the vehicle dynamics, but these have the unfortunate drawback of requiring the solution of a set of coupled differential algebraic equations (DAE). DAE's are not conducive to real-time implementation such as in a driving simulator, without a very expensive processing capability. The primary objective of this thesis is to show that multi-body models constructed from DAE's can be reasonably approximated with linear models using suspension elements that have nonlinear constitutive relationships. Three models were compared in this research, an experimental quarter-car test rig, a multi-body dynamics differential algebraic equation model, and a linear model with nonlinear suspension elements. Models constructed from differential algebraic equations are computationally expensive to compute and are difficult to realize for real-time simulations. Instead, a linear model with nonlinear elements was proposed for a more computationally efficient solution that would retain the nonlinearities of the suspension. Simplifications were made to the linear model with nonlinear elements to further reduce computation time for real-time simulation. The development process of each model is fully described in this thesis. Each model was excited with the same input and their outputs were compared. It was found that the linear model with nonlinear elements provides a reasonably good approximation of actual model with the differential algebraic equations. / Master of Science

The Global Positioning System (GPS) signal simulator plays a critical role in developing and testing GPS receivers. Unfortunately, very few commercial GPS signal simulators are user-friendly for security researchers because they fail to generate abnormal GPS signals, which are fundamentally important. In this thesis, we develop a cost efficient software defined GPS signal simulator. To reduce the design complexity, we make some reasonable assumptions about the GPS system. This simulator is able to generate clean GPS signals, as well as polluted GPS signals by jamming, multi-path, and spoofing interferences. In addition to simulating GPS signals for a single stand alone antenna, our simulator is also able to simulate GPS signals for multiple antennas, simultaneously. These features of the simulator will immensely help the security researchers in the GPS community. / Master of Science

This research focuses on the design of an Extended Reality simulator for training medical professionals in Advanced Trauma Life Support (ATLS) and pulse palpation. Existing pulse simulators have the disadvantages of being bulky, expensive, and unsuitable to be used as training tools. In addition, none of the simulators were designed to incorporate the auditory feedback of the pulse, a crucial component of continuous pulse monitoring. The developed simulator incorporates haptic, visual, and auditory feedback modes. In this work, we also conduct a comparative user study to determine the effect of multimodal feedback on different participants. Participants trained in the Audio-Haptic scenario outperformed those trained in the Haptic only scenario. These values could also be correlated with qualitative user feedback indicating that Audio-Haptic interactions were perceived as superior. With this simulator, we hope to provide medical professionals with an immersive and realistic training tool for learning the skill of palpating pulse. / Master of Science / The medical field demands accurate and precise procedures to be performed by doctors, with no room for error. Traditional training methods consist of the trainer demonstrating the technique and the student duplicating it, which increases the risk of medical errors. Advanced Trauma Life Support (ATLS) is a program designed by the American College of Surgeons to teach physicians a systematic approach to treating trauma patients. Palpating and classifying pulses is one of the steps involved in the ATLS procedure. The majority of existing ATLS and pulse simulators are not fully integrated with haptic and auditory feedback, and there has been very little research on this topic. This work describes the design and development of an Extended Reality ATLS simulator with a pulse simulator for medical student training. We conduct a user study to determine how the Audio-Haptic scenario affects the learnability of palpating pulses and ATLS procedures. Our ATLS simulator aims to provide a comprehensive training module for emergency trauma response practice for medical professionals.

With the development of the power grid into an automated system, phasor measurement units and phasor data concentrators are essential for real time control of the system. PMUs are time synchronized throughout the power system and take sample measurements in very small windows of time. Phasor Data Concentrators accept PMU data and time align the data so that a snapshot of the power system can be viewed in real time. It is unfeasible to possess enough real PMUs to thoroughly test PDCs, thus a Real Time PMU Simulator is desired. It is possible to implement a UNIX based PMU simulator that can emulate the behavior of real PMUs, while also allowing the user to alter the Synchrophasor data to test the response of a PDC. GPS is used to synchronize a UNIX machine to UTC time to match that of a real PMU. In this way, the PMU simulator will accurately behave as a PMU. This PMU data can be sent to PDCs to test the response of the device. To test extremes of the PDC, alterations were made to the PMU software to send irregular data to a PDC. The results conclude that the open source iPDC software is capable of being used for latency testing, sending late data frames, as well as sending corrupted data. The PMU simulator proved to be successful in the area of PDC testing. The purpose of this thesis is to demonstrate how the iPDC software can be implemented to test PDC's. / Master of Science

Forward operators are subjected to both physical and mental workload in their work and a way to reduce mental workload and increase productivity is to automating the crane movement. To enable study the impact of automation you need methods to estimate the forwarder operators mental workload in conventional crane work and with semi automation. This study evaluated the psychophysiological parameters; trapezius muscle activity, heart rate, heart rate variability, respiratory rate, skin conductance and finger temperature. To ensure the validity and methodology reliability one need to perform more extensive studies. As for future studies this work propose additional studies of forward operator mental workload in the simulator environment regarding heart rate, heart rate variability and respiration. / Skogsmaskinförarens arbete innebär en hög belastning såväl fysiskt som mentalt. Dels för att det innefattar moment av statiskt och repetitvt arbete och dels för att en stor mängd information bearbetas och många beslut fattas på kort tid. Mental belastning är ett begrepp för olika former av belastning som påverkar människans förmåga att bearbeta information. Det finns ingen enskild faktor som kan utgöra ett mått på mental belastning. Såväl prestation som subjektiva bedömningar och psykofysiologiska mätmetoder används för att mäta mental belastning. Exempel på psykofysiologiska mätmetoder är muskelaktivitet, hjärtfrekvens, hjärtfrekvensvariabilitet, andningsfrekvens, hudkonduktans och fingertemperatur. Ett sätt att försöka minska belastningen för skotarföraren är att automatisera vissa moment i kranens arbete. Syftet med examensarbetet var att utvärdera psykofysiologiska mätmetoder lämpliga för att beöma skillnaden i mental belastning hos skotarförare vid arbete med konventionellt- och delautomatiserat kranarbete i simulatormiljö. Resultatet visar på en potential hos analyserna hjärtfrekvens, hjärtfrekvensvariabilitet och andning för fortsatta studier. Muskelaktiviteten i form av trapezius-EMG och hudkonduktans var analyser behäftade med höga brusnivåer och artefakter i studien. Arbetet ger även en bild av komplexiteten i studier där teknik och människa interagerar. Den tekniska kapaciteten på skogsmaskiner är idag så avancerad att maskinföraren bedöms vara den begränsande faktorn för prestationen. För att öka produktiviteten i skogsbruket är det av stor vikt att den tekniska utvecklingen samspelar med interaktionen mellan människa och maskin för att främja ett hållbart skogsbruk för såväl maskinförare som för skog och miljö.