1,396,186 research outputs found
ROC curves for regression
“NOTICE: this is the author’s version of a work that was accepted for publication in Pattern Recognition. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published in Pattern Recognition Volume 46, Issue 12, December 2013, Pages 3395–3411
DOI: 10.1016/j.patcog.2013.06.014Receiver Operating Characteristic (ROC) analysis is one of the most popular tools for the visual assessment and understanding of classifier performance. In this paper we present a new representation of regression models in the so-called regression ROC (RROC) space. The basic idea is to represent over-estimation against under-estimation. The curves are just drawn by adjusting a shift, a constant that is added (or subtracted) to the predictions, and plays a similar role as a threshold in classification. From here, we develop the notions of optimal operating condition, convexity, dominance, and explore several evaluation metrics that can be shown graphically, such as the area over the RROC curve (AOC). In particular, we show a novel and significant result: the AOC is equivalent to the error variance. We illustrate the application of RROC curves to resource estimation, namely the estimation of software project effort.I would like to thank Peter Flach and Nicolas Lachiche for some very useful comments and corrections on earlier versions of this paper, especially the suggestion of drawing normalised curves (dividing x-axis and y-axis by n). This work was supported by the MEC/MINECO projects CONSOLIDER-INGENIO CSD2007-00022 and TIN 2010-21062-C02-02, GVA project Prometeo/2008/051, the COST - European Cooperation in the field of Scientific and Technical Research IC0801 AT, and the REFRAME project granted by the European Coordinated Research on Long-term Challenges in Information and Communication Sciences & Technologies ERA-Net (CHIST-ERA), and funded by the respective national research councils and ministries.Hernández-Orallo, J. (2013). ROC curves for regression. Pattern Recognition. 46(12):3395-3411. https://doi.org/10.1016/j.patcog.2013.06.014S33953411461
KM Maturity Factors Affecting High Performance in Universities
This paper aims to measure Knowledge Management Maturity (KMM) in the universities to determine the impact of knowledge
management on high performance. This study was applied on Al-Quds Open University in Gaza strip, Palestine. Asian
productivity organization model was applied to measure KMM. Second dimension which assess high performance was
developed by the authors. The controlled sample was (306). Several statistical tools were used for data analysis and hypotheses
testing, including reliability Correlation using Cronbach’s alpha, “ANOVA”, Simple Linear Regression and Step Wise
Regression.The overall findings of the current study suggest that KMM is suitable for measuring high performance. KMM
assessment shows that maturity level is in level three. Findings also support the main hypothesis and it is sub- hypotheses. The
most important factors effecting high performance are: Processes, KM leadership, People, KM Outcomes and Learning and
Innovation. Furthermore the current study is unique by the virtue of its nature, scope and way of implied investigation, as it is
the first comparative study in the universities of Palestine explores the status of KMM using the Asian productivity Model
Rough matroids based on coverings
The introduction of covering-based rough sets has made a substantial
contribution to the classical rough sets. However, many vital problems in rough
sets, including attribution reduction, are NP-hard and therefore the algorithms
for solving them are usually greedy. Matroid, as a generalization of linear
independence in vector spaces, it has a variety of applications in many fields
such as algorithm design and combinatorial optimization. An excellent
introduction to the topic of rough matroids is due to Zhu and Wang. On the
basis of their work, we study the rough matroids based on coverings in this
paper. First, we investigate some properties of the definable sets with respect
to a covering. Specifically, it is interesting that the set of all definable
sets with respect to a covering, equipped with the binary relation of inclusion
, constructs a lattice. Second, we propose the rough matroids based
on coverings, which are a generalization of the rough matroids based on
relations. Finally, some properties of rough matroids based on coverings are
explored. Moreover, an equivalent formulation of rough matroids based on
coverings is presented. These interesting and important results exhibit many
potential connections between rough sets and matroids.Comment: 15page
The Clinical Assessment in the Legal Field: An Empirical Study of Bias and Limitations in Forensic Expertise
According to the literature, psychological assessment in forensic contexts is one of the most controversial application areas for clinical psychology. This paper presents a review of systematic judgment errors in the forensic field. Forty-six psychological reports written by psychologists, court consultants, have been analyzed with content analysis to identify typical judgment errors related to the following areas: (a) distortions in the attribution of causality, (b) inferential errors, and (c) epistemological inconsistencies. Results indicated that systematic errors of judgment, usually referred also as "the man in the street," are widely present in the forensic evaluations of specialist consultants. Clinical and practical implications are taken into account. This article could lead to significant benefits for clinical psychologists who want to deal with this sensitive issue and are interested in improving the quality of their contribution to the justice system
Genetic determinants of cortical structure (thickness, surface area and volumes) among disease free adults in the CHARGE Consortium
Cortical thickness, surface area and volumes (MRI cortical measures) vary with age and cognitive function, and in neurological and psychiatric diseases. We examined heritability, genetic correlations and genome-wide associations of cortical measures across the whole cortex, and in 34 anatomically predefined regions. Our discovery sample comprised 22,824 individuals from 20 cohorts within the Cohorts for Heart and Aging Research in Genomic Epidemiology (CHARGE) consortium and the United Kingdom Biobank. Significant associations were replicated in the Enhancing Neuroimaging Genetics through Meta-analysis (ENIGMA) consortium, and their biological implications explored using bioinformatic annotation and pathway analyses. We identified genetic heterogeneity between cortical measures and brain regions, and 160 genome-wide significant associations pointing to wnt/β-catenin, TGF-β and sonic hedgehog pathways. There was enrichment for genes involved in anthropometric traits, hindbrain development, vascular and neurodegenerative disease and psychiatric conditions. These data are a rich resource for studies of the biological mechanisms behind cortical development and aging
Cortical depth dependent functional responses in humans at 7T: improved specificity with 3D GRASE
Ultra high fields (7T and above) allow functional imaging with high contrast-to-noise ratios and improved spatial resolution. This, along with improved hardware and imaging techniques, allow investigating columnar and laminar functional responses. Using gradient-echo (GE) (T2* weighted) based sequences, layer specific responses have been recorded from human (and animal) primary visual areas. However, their increased sensitivity to large surface veins potentially clouds detecting and interpreting layer specific responses. Conversely, spin-echo (SE) (T2 weighted) sequences are less sensitive to large veins and have been used to map cortical columns in humans. T2 weighted 3D GRASE with inner volume selection provides high isotropic resolution over extended volumes, overcoming some of the many technical limitations of conventional 2D SE-EPI, whereby making layer specific investigations feasible. Further, the demonstration of columnar level specificity with 3D GRASE, despite contributions from both stimulated echoes and conventional T2 contrast, has made it an attractive alternative over 2D SE-EPI. Here, we assess the spatial specificity of cortical depth dependent 3D GRASE functional responses in human V1 and hMT by comparing it to GE responses. In doing so we demonstrate that 3D GRASE is less sensitive to contributions from large veins in superficial layers, while showing increased specificity (functional tuning) throughout the cortex compared to GE
State-dependent changes of connectivity patterns and functional brain network topology in Autism Spectrum Disorder
Anatomical and functional brain studies have converged to the hypothesis that
Autism Spectrum Disorders (ASD) are associated with atypical connectivity.
Using a modified resting-state paradigm to drive subjects' attention, we
provide evidence of a very marked interaction between ASD brain functional
connectivity and cognitive state. We show that functional connectivity changes
in opposite ways in ASD and typicals as attention shifts from external world
towards one's body generated information. Furthermore, ASD subject alter more
markedly than typicals their connectivity across cognitive states. Using
differences in brain connectivity across conditions, we classified ASD subjects
at a performance around 80% while classification based on the connectivity
patterns in any given cognitive state were close to chance. Connectivity
between the Anterior Insula and dorsal-anterior Cingulate Cortex showed the
highest classification accuracy and its strength increased with ASD severity.
These results pave the path for diagnosis of mental pathologies based on
functional brain networks obtained from a library of mental states
Glacier changes in the Bavarian Alps from 1989/90 to 2006/07
The five glaciers in Bavaria which today cover a total area of less than one square kilometer were frequently monitored by geodetic methods from the mid of the 20th century. In this paper, the record is extended by new surveys in 1999 and 2006. The glaciers show a prolonged surface lowering, which is intensified compared to the 1980s and reaches maximum rates from 1999-2006. Moreover, the ice thickness of four glaciers was determined in 2006 and 2007 by geophysical field techniques and allows the calculation of ice volumes. First simple extrapolations of observed volume losses indicate that the two Berchtesgaden glaciers and Südlicher Schneeferner could disappear by 2016, while the ice of Nördlicher Schneeferner endures until 2027. Ice thicknesses and surface changes are visualized in five annexed maps.Die fünf bayerischen Gletscher, die heute insgesamt eine Fläche von weniger als einem Quadratkilometer bedecken, wurden seit der Mitte des 20. Jahrhunderts regelmäßig geodätisch aufgenommen. Diese Reihe wird hier um zwei Neuvermessungen in den Jahren 1999 und 2006 erweitert. Alle Gletscher zeigen in dem Zeitraum eine fortgesetzte Erniedrigung ihrer Oberfläche, die im Vergleich zu den 1980er Jahren verstärkt ist und in der Periode 1999-2006 Maximalwerte aufzeigt. Außerdem wurden in den Jahren 2006 und 2007 die Eisdicken von vier Gletschern durch geophysikalische Messungen bestimmt, was erstmalig die Ermittlung des verbleibenden Eisvolumens erlaubt. Erste einfache Extrapolationen der beobachteten Volumenverluste in die Zukunft deuten an, dass die beiden Gletscher in den Berchtesgadener Alpen sowie der Südliche Schneeferner bis zum Jahr 2016 verschwinden könnten, während der Nördliche Schneeferner noch bis 2027 überdauern würde. Eisdicken und Oberflächenänderungen werden anhand von fünf Karten im Anhang verdeutlicht
Multidisciplinary integrated parent and child centres in Amsterdam: a qualitative study
Background: In several countries centres for the integrated delivery of services to the parent and child have been established. In the Netherlands family health care service centres, called Parent and Child Centres (PCCs) involve multidisciplinary teams. Here doctors, nurses, midwives, maternity help professionals and educationists are integrated into multidisciplinary teams in neighbourhood-based centres. To date there has been little research on the implementation of service delivery in these centres.
Study Design: A SWOT analysis was performed by use of triangulation data; this took place by integrating all relevant published documents on the origin and organization of the PCCs and the results from interviews with PCC experts and with PCC professionals (N=91). Structured interviews were performed with PCC-professionals (health care professionals (N=67) and PCC managers N=12)) and PCC-experts (N=12) in Amsterdam and qualitatively analysed thematically. The interview themes were based on a pre-set list of codes, derived from a prior documentation study and a focus group with PCC experts.
Results: Perceived advantages of PCCs were more continuity of care, shorter communication lines, low-threshold contact between professionals and promising future perspectives. Perceived challenges included the absence of uniform multidisciplinary guidelines, delays in communication with hospitals and midwives, inappropriate accommodation for effective professional integration, differing expectations regarding the PCC-manager role among PCC-partners and the danger of professionals' needs dominating clients' needs.
Conclusions: Professionals perceive PCCs as a promising development in the integration of services. Remaining challenges involved improvements at the managerial and organizational level. Quantitative research into the improvements in quality of care and child health is recommended
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