1,200 research outputs found

    Synthesizing SoS Concepts for Use in Cost Estimation

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    Today’s need for more complex, capable systems in a short timeframe is leading many organizations towards the integration of existing systems into networkcentric, knowledge-based system-of-systems (SoS). Software and system cost model tools to date have focused on the software and system development activities of a single system. When viewing the new SoS architectures, one finds that the effort associated with the design and integration of these SoSs is not handled well, if at all, in current cost models. This paper includes (1) a comparison of various SoS definitions and concepts with respect to cost models, (2) a classification of these definitions in terms of product, process, and personnel focus, and (3) the definition of a set of discriminators for defining model boundaries and potential drivers for an SoS cost estimation model. Eleven SoS definitions are synthesized to provide reasonable coverage for different properties of SoS and illustrated in two examples

    Federated Embedded Systems – a review of the literature in related fields

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    This report is concerned with the vision of smart interconnected objects, a vision that has attracted much attention lately. In this paper, embedded, interconnected, open, and heterogeneous control systems are in focus, formally referred to as Federated Embedded Systems. To place FES into a context, a review of some related research directions is presented. This review includes such concepts as systems of systems, cyber-physical systems, ubiquitous computing, internet of things, and multi-agent systems. Interestingly, the reviewed fields seem to overlap with each other in an increasing number of ways

    Towards a Work Breakdown Structure for Net Centric System of Systems Engineering and Management

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    As the system engineering industry sees an increasing focus on the lifecycle development, acquisition, and sustainment of net-centric Systems of Systems (SoS), organizations find that current processes and tools need to evolve to handle the increased scope, scale, and complexity of these efforts. One such tool, the Work Breakdown Structure (WBS) is important in planning, monitoring, and re-focusing of program activities as requirements and goals of the program evolve. This paper provides an overview of the limitations of current standard WBSs with respect to SoS efforts and presents a proposed WBS structure that more adequately reflects the evolving processes and cross-organizational complexities

    Using a Boundary Object Framework to Analyze Interorganizational Collaboration

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    The U.S. military is facing a plethora of challenges as a result of tightening procurement budgets and the need to acquire new capabilities to operate in modern war environments. This requires integrating legacy systems with developing technologies in what is loosely defined to be a System of Systems. Most Systems of Systems require some integrator to manage and operate the system interfaces. In addition to technical integration challenges, these system integrators have the difficult undertaking of integrating various organizations. The boundary object framework proposed by this paper provides a tool for systems integrators working in System of Systems or any type of complex system to identify and categorize communication, coordination, and collaboration interfaces and address possible failures

    -ilities Tradespace and Affordability Project – Phase 3

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    One of the key elements of the SERC’s research strategy is transforming the practice of systems engineering and associated management practices – “SE and Management Transformation (SEMT).” The Grand Challenge goal for SEMT is to transform the DoD community’s current systems engineering and management methods, processes, and tools (MPTs) and practices away from sequential, single stovepipe system, hardware-first, document-driven, point- solution, acquisition-oriented approaches; and toward concurrent, portfolio and enterprise- oriented, hardware-software-human engineered, model-driven, set-based, full life cycle approaches.This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant Secretary of Defense for Research and Engineering (ASD(R&E)) under Contract H98230-08- D-0171 (Task Order 0031, RT 046).This material is based upon work supported, in whole or in part, by the U.S. Department of Defense through the Office of the Assistant Secretary of Defense for Research and Engineering (ASD(R&E)) under Contract H98230-08- D-0171 (Task Order 0031, RT 046)

    Sum-of-squares Flight Control Synthesis for Deep-stall Recovery

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    Under review for publication in the Journal of Guidance, Control, and Dynamics.In lieu of extensive Monte-Carlo simulations for flight control verification, sum-of-squares programming techniques provide an algebraic approach to the problem of nonlinear control synthesis and analysis. However, their reliance on polynomial models has hitherto limited the applicability to aeronautical control problems. Taking advantage of recently proposed piecewise polynomial models, this paper revisits sum-of-squares techniques for recovery of an aircraft from deep-stall conditions using a realistic yet tractable aerodynamic model. Local stability analysis of classical controllers is presented as well as synthesis of polynomial feedback laws with the objective of enlarging their nonlinear region of attraction. A newly developed synthesis algorithm for backwards-reachability facilitates the design of recovery control laws, ensuring stable recovery by design. The paper's results motivate future research in aeronautical sum-of-squares applications

    Optimization of Digital Filter Design Using Hardware Accelerated Simulation

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    iii Abstract The goal to this research was to develop a scheme to optimize a digital filter design using an optimization engine and hardware-accelerated simulation using a Field Programmable Gate Array (FPGA). A parameterizable generic digital filter, which was fully implemented on a prototyping board with a Xilinx Virtex-II Pro xc2vp30-7-ff896 FPGA, was developed using Xilinx System Generator for DSP. The optimization engine, which actually is a random candidate generator that will eventually be replaced by a differential evolution engine, was implemented using MATLAB along with a candidate evaluator and other supporting programs. Automatic hardware co-simulations of 100 candidate filters were performed successfully to demonstrate that this approach is feasible, reliable and efficient for complex systems
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