102,308 research outputs found
Issues of Geotechnical Engineering and Soil – Monument Interaction
No full textBouckovalas G., Gazetas G., Pitilakis K., Konstantopoulos I., Kavvadas M., Anastasopoulos I., Dimitriadi V., (2009). “Issues of Geotechnical Engineering and Soil – Monument Interaction”. Co‐financed by the European Centre on Prevention & Forecasting of Earthquakes (E.C.P.F.E.) and the Earthquake Planning & Protection Organization of Greece (E.P.P.O.
The management of internationalization:structural modifications and inter-organizational significance
No full textMarket information acquisition: a prerequisite for successful strategic entrepreneurship
No full textAbstractThis paper investigates on the types of information used by managers and entrepreneurs, so as to conduct market research and to evaluate market potential.The authors examine five major sets of variables to understand their impact on firms’ information market search effort. Empirical results based on a survey of Greek enterprises provide support for these factors in predicting firms’ market information acquisition. Findings on structural and administrative characteristics of the firms support the notion that companies engaged in greater market information search and evaluation of market potential tend to develop and implement complex penetration and development market strategies, in order to maximize their business performance in the examined market
Fixed Effects and Variance Components Estimation in Three-Level Meta-Analysis
No full textMeta-analytic methods have been widely applied to education, medicine, and the social sciences. Much of meta-analytic data are hierarchically structured since effect size estimates are nested within studies, and in turn studies can be nested within level-3 units such as laboratories or investigators, and so forth. Thus, multilevel models are a natural framework for analyzing meta-analytic data. This paper discusses the application of a Fisher scoring method in two- and three-level meta-analysis that takes into account random variation at the second and at the third levels. The usefulness of the model is demonstrated using data that provide information about school calendar types. SAS proc mixed and HLM can be used to compute the estimates of fixed effects and variance components.meta-analysis, multilevel models, random effects
Is the Persistence of Teacher Effects in Early Grades Larger for Lower-Performing Students?
No full textWe examined the persistence of teacher effects from grade to grade on lower-performing students using high-quality experimental data from Project STAR, where students and teachers were assigned randomly to classrooms of different sizes. The data included information about mathematics and reading scores and student demographics such as gender, race, and SES. Teacher effects were computed as residual classroom achievement within schools and within grades. Then, teacher effects were used as predictors of achievement in following grades and quantile regression was used to estimate their persistence. Results consistently indicated that all students benefited similarly from teachers. Overall, systematic differential teacher effects were not observed and it appears that lower-performing students benefit as much as other students from teachers. In fourth grade there was some evidence that lower-performing students benefit more from effective teachers. Results from longitudinal analyses suggested that having effective teachers in successive grades is beneficial to all students and to lower-performing students in particular in mathematics. However, having low-effective teachers in successive grades is detrimental to all students and to lower-performing students in particular in reading.quantile regression, low-achievers, teacher effects
A novel machine learning method to exploit EBSD and nanoindentation for TRIP steels microstructures analysis
No full textThe recognition of phases and microstructures in TRIP-assisted bainitic-ferritic steels is challenging and requires sophisticated techniques to gain insights and reveal mechanical features with nanoscale precision. EBSD and nanoindentation have been employed to assess the surface composition and their properties within a reporting depth of 30 nm. Correlative mechanical microscopy and data science were used to overcome the shortcomings associated with the lack of an inclusive solution that combines the metadata from both techniques. A modular methodology is presented, which involves routines for exploiting structural and mechanical data via reproducible Machine Learning models (code and data are shared). The approach is structured to facilitate reuse by research community for correlating characterization mapping data, not limited to nanoindentation and EBSD. Gaussian mixture models are adopted to extract mechanical phases utilizing the nanomechanical properties. The K-means++ method is used for the first time to mine information from Inverse Polar Figure (IPF) mapping about anisotropy and to extract the knowledge from images for each grain, including grain coordinates and size. Moreover, k-nearest-neighbours regression was used to perform data imputation to fill in the values of descriptors related to missing coordinates relative to those of nanoindentation, grain boundary, EBSD phase, and EBSD anisotropy maps
Bibliographie Hilarion G. Petzold 1958 – 2009 mit Anhang als Einführung
No full textDieses Archiv enthält die Gesamtbibliographie der Werke des Autors nebst einiger Texte „Über H. G. Petzold“ im Schlussteil der Bibliographie sowie einen Anhang mit einer Einführung in die Architektur des Werkes in seinem wissenslogischen Aufbau als Ausarbeitung seines „Tree of Science Modells“ (2007).This archive contains the complete bibliography of the author and some texts about H. G. Petzold, moreover an epilogue with an introduction to the architecture of the works in its epistemological structure and composition and as an elaborations of Petzold’s „Tree of Science Modell (2007).https://www.fpi-publikation.de/polyloge/01-2009-petzold-h-g-gesamtbibliographie-h-g-petzold-1958-2009-updating-november2009/peerReviewedpublishedVersio
Dispelling the Myths Behind First-author Citation Counts
No full textWe conducted a full-scale evaluative citation analysis study of scholars in the XML research field to explore just how different from each other author rankings resulting from different citation counting methods actually are, and to demonstrate the capability of emerging data and tools on the Web in supporting more realistic citation counting methods. Our results contest some common arguments for the continued
use of first-author citation counts in the evaluation of scholars, such as high correlations between author rankings by first-author citation counts and other citation
counting methods, and high costs of using more realistic citation counting methods that are not well-supported by the ISI databases. It is argued that increasingly available digital full text research papers make it possible for citation analysis studies to go beyond what the ISI databases have directly supported and to employ more
sophisticated methods
Incorporating Cost in Power Analysis for Three-Level Cluster Randomized Designs
No full textIn experimental designs with nested structures entire groups (such as schools) are often assigned to treatment conditions. Key aspects of the design in these cluster randomized experiments include knowledge of the intraclass correlation structure and the sample sizes necessary to achieve adequate power to detect the treatment effect. However, the units at each level of the hierarchy have a cost associated with them and thus researchers need to decide on sample sizes given a certain budget, when designing their studies. This paper provides methods for computing power within an optimal design framework (that incorporates costs of units in all three levels) for three-level cluster randomized balanced designs with two levels of nesting. The optimal sample sizes are a function of the variances at each level and the cost of each unit. Overall, larger effect sizes, smaller intraclass correlations at the second and third level, and lower cost of level-3 and level-2 units result in higher estimates of power.experimental design, statistical power, optimal sampling
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