148 research outputs found
Hydrogen Fuel in Support of Unmanned Operations in an EABO Environment
NPS NRP Project PosterNavy and Marine Corps planners developed the Expeditionary Advanced Base Operations (EABO) concept of operations to provide maritime commanders with more options for future sea control operations. Additionally, Littoral Operations in a Contested Environment (LOCE) is the concept for logistical support to multiple EABO sites. Finally, NAVPLAN 2020 and the Tri-Service Maritime Strategy detail the importance of unmanned systems capabilities to future warfighting. Many unmanned undersea and aerial systems currently in development are looking to alternative energy sources, including hydrogen, to maximize operational reach and persistence. The picture is clear, the future combat environment demands risk-worthy platforms to perform sea denial as a low-signature "inside force' that is untethered from a large petroleum supply chain. This study will assess hydrogen requirements for use as a fuel in an EABO environment to inform development of a capability evolution plan. This work will apply a holistic, systems engineering approach to develop a finite set of scenarios for hydrogen use as a fuel in an EABO environment. One scenario will be modelled to determine short, mid, and long-term requirements for: hydrogen generation and storage, fuel-cell numbers and capabilities, facilities, and safety or other '-ilities' of relevance. The goal is to investigate benefits and system of systems trade-offs with the objective of delaying fuel resupply to the greatest extent possible. This will inform identification of DOTMLPF gaps to hydrogen adoption as an enabler of EABO in LOCE and support development of a capability evolution plan. This work directly supports technology assessment & transition in support of ONR S&T objectives, as well as the analysis & assessment needs of OPNAV N-94, MCWL, and NECC. An interdisciplinary team of students and faculty from Systems Engineering, Mechanical Engineering, and Operations Research will contribute. Systems Engineering will lead the study.N9 - Warfare SystemsThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Hydrogen Fuel in Support of Unmanned Operations in an EABO Environment
NPS NRP Technical ReportNavy and Marine Corps planners developed the Expeditionary Advanced Base Operations (EABO) concept of operations to provide maritime commanders with more options for future sea control operations. Additionally, Littoral Operations in a Contested Environment (LOCE) is the concept for logistical support to multiple EABO sites. Finally, NAVPLAN 2020 and the Tri-Service Maritime Strategy detail the importance of unmanned systems capabilities to future warfighting. Many unmanned undersea and aerial systems currently in development are looking to alternative energy sources, including hydrogen, to maximize operational reach and persistence. The picture is clear, the future combat environment demands risk-worthy platforms to perform sea denial as a low-signature "inside force' that is untethered from a large petroleum supply chain. This study will assess hydrogen requirements for use as a fuel in an EABO environment to inform development of a capability evolution plan. This work will apply a holistic, systems engineering approach to develop a finite set of scenarios for hydrogen use as a fuel in an EABO environment. One scenario will be modelled to determine short, mid, and long-term requirements for: hydrogen generation and storage, fuel-cell numbers and capabilities, facilities, and safety or other '-ilities' of relevance. The goal is to investigate benefits and system of systems trade-offs with the objective of delaying fuel resupply to the greatest extent possible. This will inform identification of DOTMLPF gaps to hydrogen adoption as an enabler of EABO in LOCE and support development of a capability evolution plan. This work directly supports technology assessment & transition in support of ONR S&T objectives, as well as the analysis & assessment needs of OPNAV N-94, MCWL, and NECC. An interdisciplinary team of students and faculty from Systems Engineering, Mechanical Engineering, and Operations Research will contribute. Systems Engineering will lead the study.N9 - Warfare SystemsThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Hydrogen Fuel in Support of Unmanned Operations in an EABO Environment
NPS NRP Executive SummaryNavy and Marine Corps planners developed the Expeditionary Advanced Base Operations (EABO) concept of operations to provide maritime commanders with more options for future sea control operations. Additionally, Littoral Operations in a Contested Environment (LOCE) is the concept for logistical support to multiple EABO sites. Finally, NAVPLAN 2020 and the Tri-Service Maritime Strategy detail the importance of unmanned systems capabilities to future warfighting. Many unmanned undersea and aerial systems currently in development are looking to alternative energy sources, including hydrogen, to maximize operational reach and persistence. The picture is clear, the future combat environment demands risk-worthy platforms to perform sea denial as a low-signature "inside force' that is untethered from a large petroleum supply chain. This study will assess hydrogen requirements for use as a fuel in an EABO environment to inform development of a capability evolution plan. This work will apply a holistic, systems engineering approach to develop a finite set of scenarios for hydrogen use as a fuel in an EABO environment. One scenario will be modelled to determine short, mid, and long-term requirements for: hydrogen generation and storage, fuel-cell numbers and capabilities, facilities, and safety or other '-ilities' of relevance. The goal is to investigate benefits and system of systems trade-offs with the objective of delaying fuel resupply to the greatest extent possible. This will inform identification of DOTMLPF gaps to hydrogen adoption as an enabler of EABO in LOCE and support development of a capability evolution plan. This work directly supports technology assessment & transition in support of ONR S&T objectives, as well as the analysis & assessment needs of OPNAV N-94, MCWL, and NECC. An interdisciplinary team of students and faculty from Systems Engineering, Mechanical Engineering, and Operations Research will contribute. Systems Engineering will lead the study.N9 - Warfare SystemsThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Linear Algebraic Calculation of Green's function for Large-Scale Electronic Structure Theory
A linear algebraic method named the shifted
conjugate-orthogonal-conjugate-gradient method is introduced for large-scale
electronic structure calculation. The method gives an iterative solver
algorithm of the Green's function and the density matrix without calculating
eigenstates.The problem is reduced to independent linear equations at many
energy points and the calculation is actually carried out only for a single
energy point. The method is robust against the round-off error and the
calculation can reach the machine accuracy. With the observation of residual
vectors, the accuracy can be controlled, microscopically, independently for
each element of the Green's function, and dynamically, at each step in
dynamical simulations. The method is applied to both semiconductor and metal.Comment: 10 pages, 9 figures. To appear in Phys. Rev. B. A PDF file with
better graphics is available at http://fujimac.t.u-tokyo.ac.jp/lses
Operational Analysis and CONOPS Definition for Next Generation Mine Warfare
NPS NRP Project PosterThis project conducted operational effectiveness analysis to inform future operational concepts for mining. It defined candidate operational concepts for mining operations with a focus on capabilities and associated design requirements. It developed architectural representations of mining operations to highlight the operational activities and systems associated with mining operations and define the system design decisions (e.g., platforms, manning) that contribute to the operational effectiveness of minefield deployment. The project developed and analyzed an agent-based simulation model using the Modeling and Simulation Toolbox (MAST) feature of the Orchestrated Simulation through Modeling (OSM) framework developed by the Naval Surface Warfare Center, Dahlgren Division. The OSM MAST model was used to compare airborne, surface, and subsurface deployment strategies as well as the key performance drivers (in terms of operational activities, hostile behavior, and system design decisions) that drive operational effectiveness. Analysis demonstrated that hostile posture (defined in terms of enemy detection capability and probability to change course upon mine detection) had a larger impact on minefield effectiveness than any characteristics of the minefield, individual mine characteristics, or deployment vessel. Additional analysis was conducted on operational and design characteristics of deployed minefields which found that the quantity of the mines in the minefield had a larger impact than individual mine characteristics or deployment vessel. An isolated analysis of alternative deployment strategies found that, in general, airborne deployment vessels outperformed both surface and subsurface deployment strategies.Naval Surface Warfare Center (NSWC), Division Panama CityASN(RDA) - Research, Development, and AcquisitionThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Operational Analysis and CONOPS Definition for Next Generation Mine Warfare
NPS NRP Executive SummaryThis project conducted operational effectiveness analysis to inform future operational concepts for mining. It defined candidate operational concepts for mining operations with a focus on capabilities and associated design requirements. It developed architectural representations of mining operations to highlight the operational activities and systems associated with mining operations and define the system design decisions (e.g., platforms, manning) that contribute to the operational effectiveness of minefield deployment. The project developed and analyzed an agent-based simulation model using the Modeling and Simulation Toolbox (MAST) feature of the Orchestrated Simulation through Modeling (OSM) framework developed by the Naval Surface Warfare Center, Dahlgren Division. The OSM MAST model was used to compare airborne, surface, and subsurface deployment strategies as well as the key performance drivers (in terms of operational activities, hostile behavior, and system design decisions) that drive operational effectiveness. Analysis demonstrated that hostile posture (defined in terms of enemy detection capability and probability to change course upon mine detection) had a larger impact on minefield effectiveness than any characteristics of the minefield, individual mine characteristics, or deployment vessel. Additional analysis was conducted on operational and design characteristics of deployed minefields which found that the quantity of the mines in the minefield had a larger impact than individual mine characteristics or deployment vessel. An isolated analysis of alternative deployment strategies found that, in general, airborne deployment vessels outperformed both surface and subsurface deployment strategies.Naval Surface Warfare Center (NSWC), Division Panama CityASN(RDA) - Research, Development, and AcquisitionThis research is supported by funding from the Naval Postgraduate School, Naval Research Program (PE 0605853N/2098). https://nps.edu/nrpChief of Naval Operations (CNO)Approved for public release. Distribution is unlimited.
Krylov Subspace Method for Molecular Dynamics Simulation based on Large-Scale Electronic Structure Theory
For large scale electronic structure calculation, the Krylov subspace method
is introduced to calculate the one-body density matrix instead of the
eigenstates of given Hamiltonian. This method provides an efficient way to
extract the essential character of the Hamiltonian within a limited number of
basis set. Its validation is confirmed by the convergence property of the
density matrix within the subspace. The following quantities are calculated;
energy, force, density of states, and energy spectrum. Molecular dynamics
simulation of Si(001) surface reconstruction is examined as an example, and the
results reproduce the mechanism of asymmetric surface dimer.Comment: 7 pages, 3 figures; corrected typos; to be published in Journal of
the Phys. Soc. of Japa
Bcl-2 protein family: Implications in vascular apoptosis and atherosclerosis
Apoptosis has been recognized as a central component in the pathogenesis of atherosclerosis, in addition to the other human pathologies such as cancer and diabetes. The pathophysiology of atherosclerosis is complex, involving both apoptosis and proliferation at different phases of its progression. Oxidative modification of lipids and inflammation differentially regulate the apoptotic and proliferative responses of vascular cells during progression of the atherosclerotic lesion. Bcl-2 proteins act as the major regulators of extrinsic and intrinsic apoptosis signalling pathways and more recently it has become evident that they mediate the apoptotic response of vascular cells in response to oxidation and inflammation either in a provocative or an inhibitory mode of action. Here we address Bcl-2 proteins as major therapeutic targets for the treatment of atherosclerosis and underscore the need for the novel preventive and therapeutic interventions against atherosclerosis, which should be designed in the light of molecular mechanisms regulating apoptosis of vascular cells in atherosclerotic lesions
Digitalized service multinationals and international business theory
Banalieva and Dhanaraj argue that digital service multinationals (DSMNCs) possess a new category of firm-specific advantage (FSA), the network advantage, and that, contrary to extant theory, they use networks as a mode of governance. I review the business models used by DSMNCs, compare them to non-digital ones, and explore what we can learn about them from extant IB theory. I conclude that network advantages are not a new category of FSAs, that networks are not a mode of governance, and that their use by DSMNCs is well explained by extant theory
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