2,802 research outputs found
Arbitrating Wrongful Death Claims for Nursing Home Patients: What is Wrong With This Picture and How to Make it More Right
Sending the Wrong Message: The Current State of Minnesota Law Raises Multiple Barriers to Meaningful Resolution for Our Elder Population When Bringing Medical Malpractice Claims
Sending the Wrong Message: The Current State of Minnesota Law Raises Multiple Barriers to Meaningful Resolution for Our Elder Population When Bringing Medical Malpractice Claims
Climate-Suitable Planting as a Strategy for Maintaining Forest Productivity and Functional Diversity
Within the time frame of the longevity of tree species, climate change will change faster than the ability of natural tree migration. Migration lags may result in reduced productivity and reduced diversity in forests under current management and climate change. We evaluated the efficacy of planting climate-suitable tree species (CSP), those tree species with current or historic distributions immediately south of a focal landscape, to maintain or increase aboveground biomass, productivity, and species and functional diversity. We modeled forest change with the LANDIS-II forest simulation model for 100 years (2000–2100) at a 2-ha cell resolution and five-year time steps within two landscapes in the Great Lakes region (northeastern Minnesota and northern lower Michigan, USA). We compared current climate to low- and high-emission futures. We simulated a low-emission climate future with the Intergovernmental Panel on Climate Change (IPCC) 2007 B1 emission scenario and the Parallel Climate Model Global Circulation Model (GCM). We simulated a high-emission climate future with the IPCC A1FI emission scenario and the Geophysical Fluid Dynamics Laboratory (GFDL) GCM. We compared current forest management practices (business-asusual) to CSP management. In the CSP scenario, we simulated a target planting of 5.28% and 4.97% of forested area per five-year time step in the Minnesota and Michigan landscapes, respectively. We found that simulated CSP species successfully established in both landscapes under all climate scenarios. The presence of CSP species generally increased simulated aboveground biomass. Species diversity increased due to CSP; however, the effect on functional diversity was variable. Because the planted species were functionally similar to many native species, CSP did not result in a consistent increase nor decrease in functional diversity. These results provide an assessment of the potential efficacy and limitations of CSP management. These results have management implications for sites where diversity and productivity are expected to decline. Future efforts to restore a specific species or forest type may not be possible, but CSP may sustain a more general ecosystem service (e.g., aboveground biomass)
Optimal Structural Results for Assemble-to-Order Generalized M-Systmes
Cataloged from PDF version of article.We consider an assemble-to-order generalized M-system with multiple components and multiple products,
batch ordering of components, random lead times, and lost sales. We model the system as an in nite-horizon
Markov decision process and seek an optimal control policy, which speci es when a batch of components
should be produced and whether an arriving demand for each product should be satis ed. To facilitate
our analysis, we introduce new functional characterizations for convexity and submodularity with respect to
certain non-unitary directions. These help us characterize optimal inventory replenishment and allocation
policies under a mild condition on component batch sizes via a new type of policy: lattice-dependent base-stock
and lattice-dependent rationing
Intrinsic Metastabilities in the Charge Configuration of a Double Quantum Dot
We report a thermally activated metastability in a GaAs double quantum dot
exhibiting real-time charge switching in diamond shaped regions of the charge
stability diagram. Accidental charge traps and sensor back action are excluded
as the origin of the switching. We present an extension of the canonical double
dot theory based on an intrinsic, thermal electron exchange process through the
reservoirs, giving excellent agreement with the experiment. The electron spin
is randomized by the exchange process, thus facilitating fast, gate-controlled
spin initialization. At the same time, this process sets an intrinsic upper
limit to the spin relaxation time.Comment: 4 pages, 5 figures (color
Real-time delay announcement under competition
Internet-based technology enables firms to disseminate real-time delay information to delay-sensitive customers. We study how such delay announcements impact service providers in a competitive environment with two service providers who compete for market share. We model the service providers' strategies based on an endogenous timing game, investigating strategies that emerge in equilibrium. We determine the service providers' market shares under the various game outcomes by analyzing continuous-time Markov chains, which capture customers' joining decisions, and by developing a novel computational technique to analyze the intractable asymmetric Join-the-Shortest Queue system, providing bounds on the market shares. We find that only the lower capacity service provider announces its real-time delay under intermediate system loads and highly imbalanced capacities. However, for most parameter settings, the mere presence of a competitor induces both providers to announce delays in equilibrium, leaving customers better off on average. We relate our findings to the single-provider delay announcement literature by discussing the impact of competition on service providers, delay announcement technology firms, and customers
Reviewing energy system modelling of decentralized energy autonomy
Research attention on decentralized autonomous energy systems has increased
exponentially in the past three decades, as demonstrated by the absolute number of
publications and the share of these studies in the corpus of energy system modelling
literature. This paper shows the status quo and future modelling needs for research on
local autonomous energy systems. A total of 359 studies are roughly investigated, of
which a subset of 123 in detail. The studies are assessed with respect to the
characteristics of their methodology and applications, in order to derive common trends
and insights. Most case studies apply to middle-income countries and only focus on the
supply of electricity in the residential sector. Furthermore, many of the studies are
comparable regarding objectives and applied methods. Local energy autonomy is
associated with high costs, leading to levelized costs of electricity of 0.41 $/kWh on
average. By analysing the studies, many improvements for future studies could be
identified: the studies lack an analysis of the impact of autonomous energy systems on
surrounding energy systems. In addition, the robust design of autonomous energy
systems requires higher time resolutions and extreme conditions. Future research
should also develop methodologies to consider local stakeholders and their
preferences for energy systems
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