167 research outputs found
MATSuMoTo: The MATLAB Surrogate Model Toolbox For Computationally Expensive Black-Box Global Optimization Problems
MATSuMoTo is the MATLAB Surrogate Model Toolbox for computationally
expensive, black-box, global optimization problems that may have continuous,
mixed-integer, or pure integer variables. Due to the black-box nature of the
objective function, derivatives are not available. Hence, surrogate models are
used as computationally cheap approximations of the expensive objective
function in order to guide the search for improved solutions. Due to the
computational expense of doing a single function evaluation, the goal is to
find optimal solutions within very few expensive evaluations. The multimodality
of the expensive black-box function requires an algorithm that is able to
search locally as well as globally. MATSuMoTo is able to address these
challenges. MATSuMoTo offers various choices for surrogate models and surrogate
model mixtures, initial experimental design strategies, and sampling
strategies. MATSuMoTo is able to do several function evaluations in parallel by
exploiting MATLAB's Parallel Computing Toolbox.Comment: 13 pages, 7 figure
On the Acquisition of Polarity Items: 11- to 12-Year-Olds' Comprehension of German NPIs and PPIs
Existing work on the acquisition of polarity-sensitive expressions (PSIs) suggests that children show an early sensitivity to the restricted distribution of negative polarity items (NPIs), but may be delayed in the acquisition of positive polarity items (PPIs). However, past studies primarily targeted PSIs that are highly frequent in childrenâs language input. In this paper, we report an experimental investigation on childrenâs comprehension of two NPIs and two PPIs in German. Based on corpus data indicating that the four tested PSIs are present in child-directed speech but rare in young childrenâs utterances, we conducted an auditory rating task with adults and 11- to 12-year-old children. The results demonstrate that, even at 11â12Â years of age, children do not yet show a completely target-like comprehension of the investigated PSIs. While they are adult-like in their responses to one of the tested NPIs, their responses did not demonstrate a categorical distinction between licensed and unlicensed PSI uses for the other tested expressions. The effect was led by a higher acceptance of sentences containing unlicensed PSIs, indicating a lack of awareness for their distributional restrictions. The results of our study pose new questions for the developmental time scale of the acquisition of polarity items.Deutsche Forschungsgemeinschaft
http://dx.doi.org/10.13039/501100001659UniversitĂ€t OsnabrĂŒck (3158)Peer Reviewe
Surrogate Optimization of Deep Neural Networks for Groundwater Predictions
Sustainable management of groundwater resources under changing climatic
conditions require an application of reliable and accurate predictions of
groundwater levels. Mechanistic multi-scale, multi-physics simulation models
are often too hard to use for this purpose, especially for groundwater managers
who do not have access to the complex compute resources and data. Therefore, we
analyzed the applicability and performance of four modern deep learning
computational models for predictions of groundwater levels. We compare three
methods for optimizing the models' hyperparameters, including two surrogate
model-based algorithms and a random sampling method. The models were tested
using predictions of the groundwater level in Butte County, California, USA,
taking into account the temporal variability of streamflow, precipitation, and
ambient temperature. Our numerical study shows that the optimization of the
hyperparameters can lead to reasonably accurate performance of all models (root
mean squared errors of groundwater predictions of 2 meters or less), but the
''simplest'' network, namely a multilayer perceptron (MLP) performs overall
better for learning and predicting groundwater data than the more advanced long
short-term memory or convolutional neural networks in terms of prediction
accuracy and time-to-solution, making the MLP a suitable candidate for
groundwater prediction.Comment: submitted to Journal of Global Optimization; main paper: 25 pages, 19
figures, 1 table; online supplement: 11 pages, 18 figures, 3 table
FORMAĂĂO INICIAL DE PROFESSORES PARA USO DAS TECNOLOGIAS: A APROPRIAĂĂO DO CONHECIMENTO TECNOLĂGICO EXPRESSO NO PROJETO PEDAGĂGICO DE CURSO
FORMAĂĂO INICIAL DE PROFESSORES PARA USO DAS TECNOLOGIAS: A APROPRIAĂĂO DO CONHECIMENTO TECNOLĂGICO EXPRESSO NO PROJETO PEDAGĂGICO DE CURS
Role of Cystathionine Gamma-Lyase in Immediate Renal Impairment and Inflammatory Response in Acute Ischemic Kidney Injury
Hydrogen sulfide (H2S) is known to act protectively during renal
ischemia/reperfusion injury (IRI). However, the role of the endogenous H2S in
acute kidney injury (AKI) is largely unclear. Here, we analyzed the role of
cystathionine gamma-lyase (CTH) in acute renal IRI using CTH-deficient
(Cthâ/â) mice whose renal H2S levels were approximately 50% of control (wild-
type) mice. Although levels of serum creatinine and renal expression of AKI
marker proteins were equivalent between Cthâ/â and control mice, histological
analysis revealed that IRI caused less renal tubular damage in Cthâ/â mice.
Flow cytometric analysis revealed that renal population of infiltrated
granulocytes/macrophages was equivalent in these mice. However, renal
expression levels of certain inflammatory cytokines/adhesion molecules
believed to play a role in IRI were found to be lower after IRI only in Cthâ/â
mice. Our results indicate that the systemic CTH loss does not deteriorate but
rather ameliorates the immediate AKI outcome probably due to reduced
inflammatory responses in the kidney. The renal expression of CTH and other
H2S-producing enzymes was markedly suppressed after IRI, which could be an
integrated adaptive response for renal cell protection
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