4,327 research outputs found
Importance Sampling for Objetive Funtion Estimations in Neural Detector Traing Driven by Genetic Algorithms
To train Neural Networks (NNs) in a supervised way, estimations of an objective function must be carried out. The value of this function decreases as the training progresses and so, the number of test observations necessary for an accurate estimation has to be increased. Consequently, the training computational cost is unaffordable for very low objective function value estimations, and the use of Importance Sampling (IS) techniques becomes convenient. The study of three different objective functions is considered, which implies the proposal of estimators of the objective function using IS techniques: the Mean-Square error, the Cross Entropy error and the Misclassification error criteria. The values of these functions are estimated by IS techniques, and the results are used to train NNs by the application of Genetic Algorithms. Results for a binary detection in Gaussian noise are provided. These results show the evolution of the parameters during the training and the performances of the proposed detectors in terms of error probability and Receiver Operating Characteristics curves. At the end of the study, the obtained results justify the convenience of using IS in the training
Developments in Trait Emotional Intelligence Research
Trait emotional intelligence ("trait EI") concerns our perceptions of our emotional abilities, that is, how good we believe we are in terms of understanding, regulating, and expressing emotions in order to adapt to our environment and maintain well-being. In this article, we present succinct summaries of selected findings from research on (a) the location of trait EI in personality factor space, (b) the biological underpinnings of the construct, (c) indicative applications in the areas of clinical, health, social, educational, organizational, and developmental psychology, and (d) trait EI training. Findings to date suggest that individual differences in trait EI are a consistent predictor of human behavior across the life span
Brain activity changes with emotional words in different stages of psychosis
BackgroundTo date, a large number of functional magnetic resonance imaging (fMRI) studies have been conducted on psychosis. However, little is known about changes in brain functioning in psychotic patients using an emotional auditory paradigm at different stages of the disease. Such knowledge is important for advancing our understanding of the disorder and thus creating more targeted interventions. This study aimed to investigate whether individuals with first-episode psychosis (FEP) and chronic schizophrenia show abnormal brain responses to emotional auditory processing and to compare the responses between FEP and chronic schizophrenia. MethodsPatients with FEP (n = 31) or chronic schizophrenia (n = 23) and healthy controls (HCs, n = 31) underwent an fMRI scan while presented with both emotional and nonemotional words. ResultsUsing HC as a reference, patients with FEP showed decreased right temporal activation, while patients with chronic schizophrenia showed increased bilateral temporal activation. When comparing the patient groups, individuals with FEP showed lower frontal lobe activation. ConclusionTo the best of our knowledge, this is the first study with an emotional auditory paradigm used in psychotic patients at different stages of the disease. Our results suggested that the temporal lobe might be a key issue in the physiopathology of psychosis, although abnormal activation could also be derived from a connectivity problem. There is lower activation in the early stage and evolution to greater activation when patients become chronic. This study highlights the relevance of using emotional paradigms to better understand brain activation at different stages of psychosis
Aharonov-Bohm interferences from local deformations in graphene
One of the most interesting aspects of graphene is the tied relation between
structural and electronic properties. The observation of ripples in the
graphene samples both free standing and on a substrate has given rise to a very
active investigation around the membrane-like properties of graphene and the
origin of the ripples remains as one of the most interesting open problems in
the system. The interplay of structural and electronic properties is
successfully described by the modelling of curvature and elastic deformations
by fictitious gauge fields that have become an ex- perimental reality after the
suggestion that Landau levels can form associated to strain in graphene and the
subsequent experimental confirmation. Here we propose a device to detect
microstresses in graphene based on a scanning-tunneling-microscopy setup able
to measure Aharonov-Bohm inter- ferences at the nanometer scale. The
interferences to be observed in the local density of states are created by the
fictitious magnetic field associated to elastic deformations of the sample.Comment: Some bugs fixe
Combining Static and Dynamic Contract Checking for Curry
Static type systems are usually not sufficient to express all requirements on
function calls. Hence, contracts with pre- and postconditions can be used to
express more complex constraints on operations. Contracts can be checked at run
time to ensure that operations are only invoked with reasonable arguments and
return intended results. Although such dynamic contract checking provides more
reliable program execution, it requires execution time and could lead to
program crashes that might be detected with more advanced methods at compile
time. To improve this situation for declarative languages, we present an
approach to combine static and dynamic contract checking for the functional
logic language Curry. Based on a formal model of contract checking for
functional logic programming, we propose an automatic method to verify
contracts at compile time. If a contract is successfully verified, dynamic
checking of it can be omitted. This method decreases execution time without
degrading reliable program execution. In the best case, when all contracts are
statically verified, it provides trust in the software since crashes due to
contract violations cannot occur during program execution.Comment: Pre-proceedings paper presented at the 27th International Symposium
on Logic-Based Program Synthesis and Transformation (LOPSTR 2017), Namur,
Belgium, 10-12 October 2017 (arXiv:1708.07854
Multivariate Base Rates of Low Score on Neuropsychological Tests of Individuals with Coca Paste Use Disorder
Objective
The aim of this study was to determine the prevalence of low scores on eight commonly used neuropsychological tests to evaluate learning and memory, language, and executive functions in individuals with coca paste use disorders (CPUD) and to identify the differences with respect to a group of healthy nonconsuming subjects (HCs).
Methods
162 Colombian adults with CPUD and a group of 162 Colombian adult HCs participated in this comparative study. Eight tests (eighteen test scores) were grouped into three categories: learning and memory, language, and executive functions. Each participant was categorized based on the number of low scoring tests in specific percentile cut-off groups (25th, 16th, 10th, 5th, and 2nd).
Results
In the learning and memory domain, 89.5% of individuals with CPUD and 55.6% of HCs scored below the 25th percentile on at least one of the five test scores, in the language domain, 80.7% of individuals with CPUD and 58% of HCs and in the executive function domain, 92% of individuals with CPUD and 67.3% of HCs. Having two or more scores below the 10th percentile or 10 or more at the 5th percentile shows an optimal cut-off for determining the sensitivity and specificity for discriminating between the two groups.
Conclusions
The individuals with CPUD had a higher percentage of low scores than the HCs in the domains of learning and memory, language, and executive function. It is important for clinicians to be aware of low scores in individuals with CPUD to avoid false-positive diagnoses of cognitive impairment
An experience in modelling business process architecture
We present a mapping of a previously designed Business Process
Architecture (BPA) meta-model onto ArchiMate, i.e., the de facto standard
Enterprise Architecture (EA) modelling language. This construct mapping allows
developing process maps, i.e., descriptions of (views of) the business process
architecture of an organization. We demonstrate the development of these process maps using the Signavio Business Process Management (BPM) modelling
platform. The developed process maps are part of the organization’s enterprise
architecture model and are linked to BPMN process diagrams that detail the
functional, control-flow, data and resource aspects of the business processes
included in the process map. Our research contributes to the integration of BPM
and EA by researching BPA as a concept common to both disciplines
A 2D algorithm with asymmetric workload for the UPC conjugate gradient method
This is a post-peer-review, pre-copyedit version of an article published in Journal of Supercomputing. The final authenticated version is available online at: https://doi.org/10.1007/s11227-014-1300-0[Abstract] This paper examines four different strategies, each one with its own data distribution, for implementing the parallel conjugate gradient (CG) method and how they impact communication and overall performance. Firstly, typical 1D and 2D distributions of the matrix involved in CG computations are considered. Then, a new 2D version of the CG method with asymmetric workload, based on leaving some threads idle during part of the computation to reduce communication, is proposed. The four strategies are independent of sparse storage schemes and are implemented using Unified Parallel C (UPC), a Partitioned Global Address Space (PGAS) language. The strategies are evaluated on two different platforms through a set of matrices that exhibit distinct sparse patterns, demonstrating that our asymmetric proposal outperforms the others except for one matrix on one platform.Ministerio de EconomĂa y Competitividad; TIN2013-42148-PXunta de Galicia; GRC2013/055United States. Department of Energy; DEAC03-76SF0009
Behavioral Modernity and the Cultural Transmission of Structured Information: The Semantic Axelrod Model
Cultural transmission models are coming to the fore in explaining increases
in the Paleolithic toolkit richness and diversity. During the later
Paleolithic, technologies increase not only in terms of diversity but also in
their complexity and interdependence. As Mesoudi and O'Brien (2008) have shown,
selection broadly favors social learning of information that is hierarchical
and structured, and multiple studies have demonstrated that teaching within a
social learning environment can increase fitness. We believe that teaching also
provides the scaffolding for transmission of more complex cultural traits.
Here, we introduce an extension of the Axelrod (1997} model of cultural
differentiation in which traits have prerequisite relationships, and where
social learning is dependent upon the ordering of those prerequisites. We
examine the resulting structure of cultural repertoires as learning
environments range from largely unstructured imitation, to structured teaching
of necessary prerequisites, and we find that in combination with individual
learning and innovation, high probabilities of teaching prerequisites leads to
richer cultural repertoires. Our results point to ways in which we can build
more comprehensive explanations of the archaeological record of the Paleolithic
as well as other cases of technological change.Comment: 24 pages, 7 figures. Submitted to "Learning Strategies and Cultural
Evolution during the Paleolithic", edited by Kenichi Aoki and Alex Mesoudi,
and presented at the 79th Annual Meeting of the Society for American
Archaeology, Austin TX. Revised 5/14/1
The Myocardium in Aortic Stenosis Revisited: More Complex Than Just Myocytes and Interstitial Diffuse Fibrosis
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