3,343 research outputs found
City 5.0
Citizens’ access to goods and services in the private sector is restricted, in some cases by affordability, in other by limited availability in some areas or at some times. Public services are subject to similar restrictions. Digital technologies can help in overcoming these restrictions and by doing so shift goods and services from the private sector into the public domain. For instance, a free public live screening of an opera performance that is usually restricted to a limited number of wealthy citizens is a new form of public services that is delivered in a new way. This article explains the notion of City 5.0, a symbolic metaphor for a liveable city in which the potential of digital technologies is used to eliminate citizens’ restrictions in consuming public goods and services
Coalition Formation Algorithm of Prosumers in a Smart Grid Environment
In a smart grid environment, we study coalition formation of prosumers that
aim at entering the energy market. It is paramount for the grid operation that
the energy producers are able to sustain the grid demand in terms of stability
and minimum production requirement. We design an algorithm that seeks to form
coalitions that will meet both of these requirements: a minimum energy level
for the coalitions and a steady production level which leads to finding
uncorrelated sources of energy to form a coalition. We propose an algorithm
that uses graph tools such as correlation graphs or clique percolation to form
coalitions that meet such complex constraints. We validate the algorithm
against a random procedure and show that, it not only performs better in term
of social welfare for the power grid, but also that it is more robust against
unforeseen production variations due to changing weather conditions for
instance.Comment: 6 pages, 4 figures, 1 table. submited to ICC 201
A cluster partitioning method: determination of density matrices of solids and comparison with X-ray experiments
In this paper we show that 1-electron properties such as Compton profiles and
structure factors of crystals can be asymptotically retrieved through
cluster-based calculations, followed by an appropriate partition of the
1-electron reduced density matrix (1RDM). This approach, conceptually simple,
is checked with respects to both position and momentum spaces simultaneously
for insulators and a covalent crystal. Restricting the calculations to small
clusters further enables a fair description of local correlation effects in
ionic compounds, which improves both Compton profiles and structure factors vs.
their experimentally determined counterparts.Comment: 19 pages, 9 figures, 3 tables. Currently submitted to PR
mlr3spatiotempcv: Spatiotemporal resampling methods for machine learning in R
Spatial and spatiotemporal machine-learning models require a suitable
framework for their model assessment, model selection, and hyperparameter
tuning, in order to avoid error estimation bias and over-fitting. This
contribution reviews the state-of-the-art in spatial and spatiotemporal
cross-validation, and introduces the {R} package {mlr3spatiotempcv} as an
extension package of the machine-learning framework {mlr3}. Currently various
{R} packages implementing different spatiotemporal partitioning strategies
exist: {blockCV}, {CAST}, {skmeans} and {sperrorest}. The goal of
{mlr3spatiotempcv} is to gather the available spatiotemporal resampling methods
in {R} and make them available to users through a simple and common interface.
This is made possible by integrating the package directly into the {mlr3}
machine-learning framework, which already has support for generic
non-spatiotemporal resampling methods such as random partitioning. One
advantage is the use of a consistent nomenclature in an overarching
machine-learning toolkit instead of a varying package-specific syntax, making
it easier for users to choose from a variety of spatiotemporal resampling
methods. This package avoids giving recommendations which method to use in
practice as this decision depends on the predictive task at hand, the
autocorrelation within the data, and the spatial structure of the sampling
design or geographic objects being studied.Comment: 35 pages, 15 Figures, 1 Tabl
Metformin-mediated increase in DICER1 regulates microRNA expression and cellular senescence
Metformin, an oral hypoglycemic agent, has been used for
decades to treat type 2 diabetes mellitus. Recent studies indicate
that mice treated with metformin live longer and have fewer
manifestations of age-related chronic disease. However, the
molecular mechanisms underlying this phenotype are unknown.
Here, we show that metformin treatment increases the levels of
the microRNA-processing protein DICER1 in mice and in humans
with diabetes mellitus. Our results indicate that metformin
upregulates DICER1 through a post-transcriptional mechanism
involving the RNA-binding protein AUF1. Treatment with metformin
altered the subcellular localization of AUF1, disrupting its
interaction with DICER1 mRNA and rendering DICER1 mRNA
stable, allowing DICER1 to accumulate. Consistent with the role
of DICER1 in the biogenesis of microRNAs, we found differential
patterns of microRNA expression in mice treated with metformin
or caloric restriction, two proven life-extending interventions.
Interestingly, several microRNAs previously associated with
senescence and aging, including miR-20a, miR-34a, miR-130a,
miR-106b, miR-125, and let-7c, were found elevated. In agreement
with these findings, treatment with metformin decreased
cellular senescence in several senescence models in a DICER1-
dependent manner. Metformin lowered p16 and p21 protein
levels and the abundance of inflammatory cytokines and oncogenes
that are hallmarks of the senescence-associated secretory
phenotype (SASP). These data lead us to hypothesize that
changes in DICER1 levels may be important for organismal aging
and to propose that interventions that upregulate DICER1
expression (e.g., metformin) may offer new pharmacotherapeutic
approaches for age-related disease
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