16,540 research outputs found
Absorptive capacity and the growth and investment effects of regional transfers : a regression discontinuity design with heterogeneous treatment effects
Researchers often estimate average treatment effects of programs without investigating heterogeneity across units. Yet, individuals, firms, regions, or countries vary in their ability, e.g., to utilize transfers. We analyze Objective 1 Structural Funds transfers of the European Commission to regions of EU member states below a certain income level by way of a regression discontinuity
design with systematically heterogeneous treatment effects. Only about 30% and 21% of the regions - those with sufficient human capital and good-enough institutions - are able to turn transfers into faster per-capita
income growth and per-capita investment. In general, the variance of the treatment effect is much bigger than its mean
Heterogeneous data source integration for smart grid ecosystems based on metadata mining
The arrival of new technologies related to smart grids and the resulting ecosystem of applications andmanagement systems pose many new problems. The databases of the traditional grid and the variousinitiatives related to new technologies have given rise to many different management systems with several formats and different architectures. A heterogeneous data source integration system is necessary toupdate these systems for the new smart grid reality. Additionally, it is necessary to take advantage of theinformation smart grids provide. In this paper, the authors propose a heterogeneous data source integration based on IEC standards and metadata mining. Additionally, an automatic data mining framework isapplied to model the integrated information.Ministerio de Economía y Competitividad TEC2013-40767-
Increasing the Efficiency of Rule-Based Expert Systems Applied on Heterogeneous Data Sources
Nowadays, the proliferation of heterogeneous data sources provided by different
research and innovation projects and initiatives is proliferating more and more and
presents huge opportunities. These developments create an increase in the number
of different data sources, which could be involved in the process of decisionmaking
for a specific purpose, but this huge heterogeneity makes this task difficult.
Traditionally, the expert systems try to integrate all information into a main
database, but, sometimes, this information is not easily available, or its integration
with other databases is very problematic. In this case, it is essential to establish
procedures that make a metadata distributed integration for them. This process
provides a “mapping” of available information, but it is only at logic level. Thus, on
a physical level, the data is still distributed into several resources. In this sense, this
chapter proposes a distributed rule engine extension (DREE) based on edge computing
that makes an integration of metadata provided by different heterogeneous
data sources, applying then a mathematical decomposition over the antecedent of
rules. The use of the proposed rule engine increases the efficiency and the capability
of rule-based expert systems, providing the possibility of applying these rules over
distributed and heterogeneous data sources, increasing the size of data sets that
could be involved in the decision-making process
Microstructure modelling of hot deformation of Al–1%Mg alloy
This study presents the application of the finite elementmethod and intelligent systems techniques to the
prediction of microstructural mapping for aluminium alloys. Here, the material within each finite element
is defined using a hybrid model. The hybrid model is based on neuro-fuzzy and physically based components
and it has been combined with the finite element technique. The model simulates the evolution of
the internal state variables (i.e. dislocation density, subgrain size and subgrain boundary misorientation)
and their effect on the recrystallisation behaviour of the stock. This paper presents the theory behind
the model development, the integration between the numerical techniques, and the application of the
technique to a hot rolling operation using aluminium, 1 wt% magnesium alloy. Furthermore, experimental
data from plane strain compression (PSC) tests and rolling are used to validate the modelling outcome.
The results show that the recrystallisation kinetics agree well with the experimental results for different
annealing times. This hybrid approach has proved to be more accurate than conventional methods using empirical equations
Alternative Approaches to Evaluation in Empirical Microeconomics
This paper reviews some of the most popular policy evaluation methods in empirical microeconomics: social experiments, natural experiments, matching, instrumental variables, discontinuity design, and control functions. It discusses identification of traditionally used average parameters and more complex distributional parameters. The adequacy, assumptions, and data requirements of each approach are discussed drawing on empirical evidence from the education and employment policy evaluation literature. A workhorse simulation model of education returns is used throughout the paper to discuss and illustrate each approach. The full set of STATA datasets and do-files are available free online and can be used to reproduce all estimation and simulation results.evaluation methods
Alternative Approaches to Evaluation in Empirical Microeconomics
This paper reviews a range of the most popular policy evaluation methods in empirical microeconomics: social experiments, natural experiments, matching methods, instrumental variables, discontinuity design and control functions. It discusses the identification of both the traditionally used average parameters and more complex distributional parameters. In each case, the necessary assumptions and the data requirements are considered. The adequacy of each approach is discussed drawing on the empirical evidence from the education and labor market policy evaluation literature. We also develop an education evaluation model which we use to carry through the discussion of each alternative approach. A full set of STATA datasets are provided free online which contain Monte-Carlo replications of the various specifications of the education evaluation model. There are also a full set of STATA .do files for each of the estimation approaches described in the paper. The .do-files can be used together with the datasets to reproduce all the results in the paper.Evaluation methods, policy evaluation, matching methods, instrumental variables, social experiments, natural experiments, difference-in-differences, discontinuity design, control function.
Alternative approaches to evaluation in empirical microeconomics
This paper reviews a range of the most popular policy evaluation methods in empirical microeconomics: social experiments, natural experiments, matching methods, instrumental variables, discontinuity design and control functions. It discusses the identification of both the traditionally used average parameters and more complex distributional parameters. In each case, the necessary assumptions and the data requirements are considered. The adequacy of each approach is discussed drawing on the empirical evidence from the education and labor market policy evaluation literature. We also develop an education evaluation model which we use to carry through the discussion of each alternative approach. A full set of STATA datasets are provided free online which contain Monte-Carlo replications of the various specifications of the education evaluation model. There are also a full set of STATA .do files for each of the estimation approaches described in the paper. The .do-files can be used together with the datasets to reproduce all the results in the paper.
Enabling Explainable Fusion in Deep Learning with Fuzzy Integral Neural Networks
Information fusion is an essential part of numerous engineering systems and
biological functions, e.g., human cognition. Fusion occurs at many levels,
ranging from the low-level combination of signals to the high-level aggregation
of heterogeneous decision-making processes. While the last decade has witnessed
an explosion of research in deep learning, fusion in neural networks has not
observed the same revolution. Specifically, most neural fusion approaches are
ad hoc, are not understood, are distributed versus localized, and/or
explainability is low (if present at all). Herein, we prove that the fuzzy
Choquet integral (ChI), a powerful nonlinear aggregation function, can be
represented as a multi-layer network, referred to hereafter as ChIMP. We also
put forth an improved ChIMP (iChIMP) that leads to a stochastic gradient
descent-based optimization in light of the exponential number of ChI inequality
constraints. An additional benefit of ChIMP/iChIMP is that it enables
eXplainable AI (XAI). Synthetic validation experiments are provided and iChIMP
is applied to the fusion of a set of heterogeneous architecture deep models in
remote sensing. We show an improvement in model accuracy and our previously
established XAI indices shed light on the quality of our data, model, and its
decisions.Comment: IEEE Transactions on Fuzzy System
Segmented software cost estimation models based on fuzzy clustering
Parametric software cost estimation models are based on mathematical relations, obtained from the study of historical software projects
databases, that intend to be useful to estimate the effort and time required to develop a software product. Those databases often
integrate data coming from projects of a heterogeneous nature. This entails that it is difficult to obtain a reasonably reliable single parametric
model for the range of diverging project sizes and characteristics. A solution proposed elsewhere for that problem was the use of
segmented models in which several models combined into a single one contribute to the estimates depending on the concrete characteristic
of the inputs. However, a second problem arises with the use of segmented models, since the belonging of concrete projects to segments or
clusters is subject to a degree of fuzziness, i.e. a given project can be considered to belong to several segments with different degrees.
This paper reports the first exploration of a possible solution for both problems together, using a segmented model based on fuzzy
clusters of the project space. The use of fuzzy clustering allows obtaining different mathematical models for each cluster and also allows
the items of a project database to contribute to more than one cluster, while preserving constant time execution of the estimation process.
The results of an evaluation of a concrete model using the ISBSG 8 project database are reported, yielding better figures of adjustment
than its crisp counterpart.Ministerio de Ciencia y Tecnología TIN2004-06689-C0
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