Thesis (M.S.)--Oregon State University, 2003. / Typescript (photocopy). Includes bibliographical references (leaves 57-62). Also available online.

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<p>System of Systems Engineering (SoSE) is an emerging technical discipline that is increasingly referenced in industry, primarily due to the explosion of technology over recent decades. Its meteoric rise, however, has not been followed by a comprehensive study of what truly defines this new methodology. Despite its widespread use, SoSE still lacks a cohesive, agreed-upon definition or standard curriculum. </p><p> This thesis defines a common, cross-disciplinary framework for SoSE that can be further developed through collaboration between academics and technical professionals. After establishing key SoSE concepts and their roots in traditional SE, this thesis reviews a wide spectrum of present applications and opportunities for future use of SoSE principles in hopes of encouraging a more unified understanding and development of SoSE as a technical discipline. </p>

<p> Continuing population growth and increased urbanization within disaster-prone areas have led to greater numbers of mass casualties and economic losses caused by natural or human-made disasters. Efficient decision-making processes are crucial in all phases of a disaster life cycle, from mitigation and preparedness to response and recovery. The overarching goal of this dissertation is to contribute to region-wide disaster operation management capabilities by creating a set of tools to facilitate fast, life-saving decision-making. The dissertation begins with initial first responders&rsquo; assignments to affected structures and spans health care and infrastructure preparation and response. In mass casualty incident (MCI) circumstances in particular, situations are complicated, networks are often large, and conditions are transient and time-dependent. Thus, models developed in this thesis evaluate and update decisions based on available information at each point in time to the system. </p><p> The functioning of various response networks, whether in the disaster scene or at the health care facilities, is conceptualized mathematically. Each model can be viewed as a type of queueing network in which MCI victims are customers and responders or health care facilities are servers. Each queueing network is employed to: (1) test developed protocols, acting as queueing system operational policies to support disaster response, (2) assess tactics developed otherwise, or (3) optimize regional resiliency of the health care system given its dependence on set of interdependent supporting lifelines in disasters through preparedness and response actions. Resource-constrained patient flow models of hospitals are presented for routine and emergency operations for the purpose of the study. Using queueing network conceptualizations, discrete event simulation and simulation-based optimization techniques are developed to propose and evaluate protocols that guide responses and for assessing performance and resilience of these systems.</p><p>

<p> The contributions of this dissertation increase the fidelity of conceptual hypersonic mission design through the following innovations: 1) the introduction of coupling between the effects of ablation of the thermal protection system (TPS) and flight dynamics, 2) the introduction of rigid body dynamics into trajectory design, and 3) simplifying the design of hypersonic missions that involve multiple phases of flight. These contributions are combined into a unified conceptual mission design framework, which is in turn applicable to slender hypersonic vehicles with ablative TPS. Such vehicles are employed in military applications, wherein speed and terminal energy are of critical importance. </p><p> The fundamental observation that results from these contributions is the substantial reduction in the maximum terminal energy that is achievable when compared to the state-of-the art conceptual design process. Additionally, the control history that is required to follow the maximum terminal energy trajectory is also significantly altered, which will in turn bear consequence on the design of the control actuators. </p><p> The other important accomplishment of this dissertation is the demonstration of the ability to solve these class of problems using indirect methods. Despite being built on a strong foundation of the calculus of variations, the state-of-the-art entirely neglects indirect methods because of the challenge associated with solving the resulting boundary value problem (BVP) in a system of differential-algebraic equations (DAEs). Instead, it employs direct methods, wherein the optimality of the calculated trajectory is not guaranteed. The ability to employ indirect methods to solve for optimal trajectories that are comprised of multiple phases of flight while also accounting for the effects of ablation of the TPS and rigid body dynamics is a substantial advancement in the state-of-the-art.</p><p>

<p> In the U.S. medical sector, software failures in safety-critical systems in healthcare have led to serious adverse health problems, including patient deaths and recalls of medical systems. Despite the efforts in developing techniques to build resilient systems, there is a lack of consensus regarding the definition of resilience metrics and a limited number of quantitative analysis approaches. In addition, there is insufficient guidance on evaluating resilience design patterns and the value they can bring to safety-critical systems. </p><p> This research employed the interdependency analysis framework to evaluate the static resilience of safety-critical systems used in the healthcare field and identified software subsystems that are vulnerable to failures. Resilience design patterns were first implemented to these subsystems to improve their ability to withstand failures. This implementation was followed by an evaluation to determine the overall impacts on system&rsquo;s static resilience. </p><p> The methodology used a common medical system structure that collects common attributes from various medical devices and reflects major functionalities offered by multiple medical systems. Fault tree analysis and Bayesian analysis were used to evaluate the static resilience aspects of medical safety-critical systems, and two design patterns were evaluated within the praxis context: <i> Monitoring</i> and <i>N-modular redundancy</i> resilience patterns. </p><p> The results ultimately showed that resilience design patterns improve the static resilience of safety-critical systems significantly. While this research suggests the importance of resilience design patterns, this study was limited to explore the impact of structural resilience patterns on static resilience. Thus, to evaluate the overall resilience of the system, more research is needed to evaluate dynamic resilience in addition to studying the impact of different types of resilience design patterns. </p><p>

<p> This qualitative, descriptive case study explored the social learning process within complex systems as described by product support managers (PSMs) assigned to acquisition programs within the Naval Air Systems Command. The research questions asked how individuals, as influenced by their values and structure, shape their interactions and behavior in a complex environment. Nine PSMs for major acquisition and sustainment programs were referred by senior leaders and participated in the study.</p><p> Data were collected through in-depth interviews that were transcribed to capture the PSMs&rsquo; experiences and then synthesized into contextual and social learning profiles. The findings resulted in seven themes. (1) PSMs operate in complex, dynamic, and variably resourced environments that are highly dependent on interaction and result in uniquely executed programs. (2) The highly structured environment and functionally oriented structure diminish the authority of the individual and present barriers to interaction. (3) The highly structured and boundary-rich environment limits information flow and presents difficulty in communication and developing routines that align meanings, value orientations, and shared understanding across those boundaries. (4) PSMs attempt to adjust, increase, and routinize interactions but often react to emerging needs with limited authority and resources, which often leaves short-term and least helpful alternatives. (5) PSMs leverage key relationships as bridges of information but often receive limited feedback to resolve short-term issues to complete tasks. (6) PSMs are aligned with organizational goals and values to improve user outcomes and speed of delivering products, but there is value incongruency between expectations and what they want to do to achieve those outcomes. (7) PSMs experience role ambiguity, as they are torn between how much they want to develop the team and interactions versus becoming an expert and accomplishing tasks.</p><p> The study concluded that PSMs are effectively <i>leveraging different operating system</i> views to maximize the variety of the small alternatives they have; <i>countering the power of the system</i> through meaning making, developing their unique abilities (as well as their team&rsquo;s) and trying to reduce their isolation; and <i>increasing the available space for social learning</i> to make progress through trial and error and satisficing.</p><p>

<p> Poor mathematics and science skills are one of the leading challenges for advanced STEM career preparedness. There is currently a national deficit in prepared STEM career interest and readiness. A national decline prompted plans for the development of more rigorous standards. Changes in K-12 education were developed through Common Core and New Generation Science Standards. These changes were expected to better prepare students for post secondary educational opportunities such as college or technical school. This research studied effects of perceptions of the impact of high school STEM classes on career choices in two Tennessee schools that are actively participating in the Tennessee STEM Innovation Network and have actively implemented a STEM program since 2012. There is no evidence of research regarding student perceptions of STEM classes regarding STEM implementation in the state of Tennessee since 2012. According to the results of this study, students&rsquo; perceptions between subgroups showed no statistical significance regarding readiness or interest in STEM regarding college and career. The subgroups studied included race/culture, gender, classification by grade, and school attended.</p><p>

<p> Over the last 70 years, teams have become the ubiquitous unit of work in our organizations. The software industry heavily utilizes the Scrum methodology to develop software. Scrum is a team-based methodology that requires the constant formation and development of team capabilities. Researchers and practitioners dealing with work team dynamics have relied on the popular team developmental stages of forming, storming, norming, and performing, defined by Dr. Bruce Tuckman in 1965. However, this framework was conceived primarily from articles dealing with therapy groups and not modern teams. This study expands the body of research in work team stage development applied to Scrum, a methodology that itself has no social science foundation and minimal theoretical coverage. </p><p> A combined case study and grounded theory method is used to leverage the strengths of both to investigate the developmental stage of 5 Scrum teams at a high-tech company. A questionnaire along with team interviews were utilized to gather data on how teams relate to developmental factors found in the literature. Descriptive analytics were leveraged to uncover the questionnaire findings, and grounded theory analysis was applied to code interview answers into usable concepts, categories, and themes. Themes were further explored concerning their causal relationships. </p><p> The study proposed and validated 12 theoretical factors that contribute to the stage development of Scrum teams across 4 distinct stages. These factors interconnect and form 4 quadrants with unique dynamics associated with a team&rsquo;s mission, structure, execution, and teaming. Furthermore, higher stage teams proved to be self-managed and adaptable and able to handle higher task complexity. Leaders were observed shifting roles as teams evolved through stages. This latter finding is consistent with the theoretical model of Kozlowski, Watola, Jensen, Kim, and Botero. The research also identified common challenges that teams encounter in their development. </p><p> The findings from this study can help organizations who practice Scrum become more intentional about the development of their teams toward adaptability. A concerted effort by software organizations to optimize the evolution of teams across the factors found in the study could yield significant benefits, particularly for missions dealing with high complexity and innovation needs.</p><p>

abstract: VTOL drones were designed and built at the beginning of the 20th century for military applications due to easy take-off and landing operations. Many companies like Lockheed, Convair, NASA and Bell Labs built their own aircrafts but only a few from them came in to the market. Usually, flight automation starts from first principles modeling which helps in the controller design and dynamic analysis of the system. In this project, a VTOL drone with a shape similar to a Convair XFY-1 is studied and the primary focus is stabilizing and controlling the flight path of the drone in its hover and horizontal flying modes. The model of the plane is obtained using first principles modeling and controllers are designed to stabilize the yaw, pitch and roll rotational motions. The plane is modeled for its yaw, pitch and roll rotational motions. Subsequently, the rotational dynamics of the system are linearized about the hover flying mode, hover to horizontal flying mode, horizontal flying mode, horizontal to hover flying mode for ease of implementation of linear control design techniques. The controllers are designed based on an H∞ loop shaping procedure and the results are verified on the actual nonlinear model for the stability of the closed loop system about hover flying, hover to horizontal transition flying, horizontal flying, horizontal to hover transition flying. An experiment is conducted to study the dynamics of the motor by recording the PWM input to the electronic speed controller as input and the rotational speed of the motor as output. A theoretical study is also done to study the thrust generated by the propellers for lift, slipstream velocity analysis, torques acting on the system for various thrust profiles. / Dissertation/Thesis / Masters Thesis Electrical Engineering 2018