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61.
62.
Manuel Pedro Rodríguez Bolívar Laura Alcaide Muñoz Antonio M. López Hernández 《Information Technology for Development》2016,22(1):36-74
Many countries have implemented changes in public-sector management models, based on the strategic and intensive use of new information and communication technologies. From a critical standpoint, this paper analyzes and characterizes the contributions made by research in the field of e-government, identifying future areas of interest and potentially valuable methodologies. In addition, it compares research efforts focused on developing countries with those concerning developed economies, in order to identify research gaps and possibilities for improvement in the context of e-government research in developing countries. Diverse scientometric approaches are employed in this analysis of papers published by international journals listed in the SSCI index in the fields of Public Administration and of Information Science & Library Science. Our findings reveal the existence of various research gaps and highlight areas that should be addressed in future research, especially in developing countries. Indeed, the research approach to e-government remains immature, focusing on particular cases or dimensions, while little has been done to produce theories or models to clarify and explain the political processes of e-government. In addition, significant differences are found between the impact of scientific output and patterns of scientific production as regards developing and developed countries. 相似文献
63.
Javier de Vicente Daniel Rodríguez Vassilis Theofilis Eusebio Valero 《Computers & Fluids》2011,43(1):143-153
Three-dimensional linear instability analyses are presented of steady two-dimensional laminar flows in the lid-driven cavity defined by [15] and further analyzed in the present volume [1], as well as in a derivative of the same geometry. It is shown that in both of the geometries considered three-dimensional BiGlobal instability leads to deviation of the flow from the two-dimensional solution; the analysis results are used to define low- and high-Reynolds number solutions by reference to the flow physics. Critical conditions for linear global instability and neutral loops are presented in both geometries. 相似文献
64.
Guillermo Mendez 《Computational statistics & data analysis》2011,55(11):2937-2950
Random forest, a data-mining technique which uses multiple classification or regression trees, is a popular algorithm used for prediction. Inference and goodness-of-fit assessment, however, may require an estimator of variability; in many applications the residual variance is of primary interest. This paper proposes two estimators of residual variance for random forest regression that take advantage of byproducts of the algorithm. The first estimator is based on the residual sum of squares from a random forest fit and uses a bootstrap bias correction. The second estimator is a difference-based estimator that uses proximity measures as weights. The estimators are evaluated through Monte Carlo simulations. Applications of the methods to the problem of assessing the relative variability of males and females on cognitive and achievement tests are discussed, and the methods are applied to estimate the residual variance in test scores for male and female students on the mathematics portion of the 2007 Arizona Instrument to Measure Standards. 相似文献
65.
66.
郑霞 《数码设计:surface》2008,(3):191-193
本文对近代年画中出现的传统女性形象进行了描述与分析,试图通过对视觉形象的剖析来寻找在中国传统文化下,有关女性美的审美传统,同时探究这一传统又以何种视觉形式在极为活跃的市民艺术领域得以传承。 相似文献
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68.
Designed 3 experiments to assess 24 preschool (mean age 64.63 mo), 24 1st-grade (mean age 76.25 mo), and 24 2nd grade (mean age 88.61 mo) children's understanding of the term word. A modified aural discrimination task was used in which Ss were required to discriminate word from nonword stimuli along only 1 dimension at a time. Exp I tested Ss' discrimination of words and sounds. Exp II examined word–phrase differentiation. Both of these experiments followed previous research in examining children's comprehension of the term word in relation to nouns. Exp III examined Ss' understanding of word with stimuli from a variety of form classes. Results indicate that Ss' word concepts have been underestimated in past research suggesting that young children lack an adequate word concept: although preschool Ss did not understand the term properly, by 1st grade word was understood. These experiments also show that Ss benefited from brief training in which they were taught to attach the metalinguistic label word to their developing concept of the word as a unit of spoken language. (38 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
69.
36 left-handed and 36 right-handed kindergarten children were asked to print after seeing a series of reversible letters and numbers presented individually on slides or flash cards. Regardless of handedness, both groups of Ss found the left–right orientation cues of the same letters and numbers difficult to recall. This challenges a proposal expressed in the "grammar of action" that claims that certain reversal errors in children's printing result from the inappropriate application of the horizontal motor rule, because although left- and right-handed children use this rule, they do so in different ways and therefore should have produced different errors. Another sample of 86 right-handed children from nursery school through Grade 1 was given the same printing task. Findings from this 2nd sample provide an additional challenge to the grammar of action by showing that reversals of the letter N, which are also thought to result from a misapplication of motor rules, decrease in frequency along with reversals of other letters and numbers, instead of increasing as predicted, during the developmental period when the motor rules that are said to be responsible for reversals of this particular letter become more strongly established. (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
70.
Comments on J. J. Christensen-Szalanski and L. R. Beach's (see record 1984-21471-001) conclusion that the attention given to commentaries and replies to articles did not justify the extra space and argues that citation indexes do not measure the major usefulness of these commentaries. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献