74 research outputs found
Robustness and Adaptiveness Analysis of Future Fleets
Making decisions about the structure of a future military fleet is a
challenging task. Several issues need to be considered such as the existence of
multiple competing objectives and the complexity of the operating environment.
A particular challenge is posed by the various types of uncertainty that the
future might hold. It is uncertain what future events might be encountered; how
fleet design decisions will influence and shape the future; and how present and
future decision makers will act based on available information, their personal
biases regarding the importance of different objectives, and their economic
preferences. In order to assist strategic decision-making, an analysis of
future fleet options needs to account for conditions in which these different
classes of uncertainty are exposed. It is important to understand what
assumptions a particular fleet is robust to, what the fleet can readily adapt
to, and what conditions present clear risks to the fleet. We call this the
analysis of a fleet's strategic positioning. This paper introduces how
strategic positioning can be evaluated using computer simulations. Our main aim
is to introduce a framework for capturing information that can be useful to a
decision maker and for defining the concepts of robustness and adaptiveness in
the context of future fleet design. We demonstrate our conceptual framework
using simulation studies of an air transportation fleet. We capture uncertainty
by employing an explorative scenario-based approach. Each scenario represents a
sampling of different future conditions, different model assumptions, and
different economic preferences. Proposed changes to a fleet are then analysed
based on their influence on the fleet's robustness, adaptiveness, and risk to
different scenarios
Real Time Predictive and Adaptive Hybrid Powertrain Control Development via Neuroevolution
The real-time application of powertrain-based predictive energy management (PrEM) brings the prospect of additional energy savings for hybrid powertrains. Torque split optimal control methodologies have been a focus in the automotive industry and academia for many years. Their real-time application in modern vehicles is, however, still lagging behind. While conventional exact and non-exact optimal control techniques such as Dynamic Programming and Model Predictive Control have been demonstrated, they suffer from the curse of dimensionality and quickly display limitations with high system complexity and highly stochastic environment operation. This paper demonstrates that Neuroevolution associated drive cycle classification algorithms can infer optimal control strategies for any system complexity and environment, hence streamlining and speeding up the control development process. Neuroevolution also circumvents the integration of low fidelity online plant models, further avoiding prohibitive embedded computing requirements and fidelity loss. This brings the prospect of optimal control to complex multi-physics system applications. The methodology presented here covers the development of the drive cycles used to train and validate the neurocontrollers and classifiers, as well as the application of the Neuroevolution process
Resilience assessment and planning in power distribution systems:Past and future considerations
Over the past decade, extreme weather events have significantly increased
worldwide, leading to widespread power outages and blackouts. As these threats
continue to challenge power distribution systems, the importance of mitigating
the impacts of extreme weather events has become paramount. Consequently,
resilience has become crucial for designing and operating power distribution
systems. This work comprehensively explores the current landscape of resilience
evaluation and metrics within the power distribution system domain, reviewing
existing methods and identifying key attributes that define effective
resilience metrics. The challenges encountered during the formulation,
development, and calculation of these metrics are also addressed. Additionally,
this review acknowledges the intricate interdependencies between power
distribution systems and critical infrastructures, including information and
communication technology, transportation, water distribution, and natural gas
networks. It is important to understand these interdependencies and their
impact on power distribution system resilience. Moreover, this work provides an
in-depth analysis of existing research on planning solutions to enhance
distribution system resilience and support power distribution system operators
and planners in developing effective mitigation strategies. These strategies
are crucial for minimizing the adverse impacts of extreme weather events and
fostering overall resilience within power distribution systems.Comment: 27 pages, 7 figures, submitted for review to Renewable and
Sustainable Energy Review
Una revisión del planeamiento de la defensa por capacidades en España (2005-16)
El artÃculo estudia el planeamiento de la defensa nacional contemporáneo desde la promulgación de la Orden Ministerial 37/2005 que inaugura el planeamiento basado en capacidades hasta la emisión de la Orden Ministerial 60/2015 que lo actualiza, flexibiliza y racionaliza. Se estudiarán las caracterÃsticas definidoras de este proceso, se describirá su funcionamiento, se evaluarán sus principales virtudes y limitaciones y se propondrán varias ideas para optimizar los ciclos de planeamiento
Resilience capacities assessment for critical infrastructures disruption: The READ framework (part 1)
We suggest an approach to assessing critical infrastructure resilience (CIR) as a step towards informed resource allocation and operation when planning to cope with CI disruptions in the context of emergency management or multi stakeholder planning. The approach is capabilities-based, where a capability is defined as a combination of assets, resources and routines specifically arranged to accomplish a critical task and assure a key objective. The capabilities (intra- and inter-institutional) are grouped into clusters according to the resilience phase (preventive, absorptive, adaptive and restorative) where they are invoked; and according to the system type (technical, operational, social and economic) which they belong to. An overall resilience capability building cycle completes the framework, enabling a systematic implementation of relevant capabilities and making gap analysis with regard to resilience deficits. A simplified test case exemplifying the use of the framework in the context of a regional public-private collaboration for CIR is provided
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