A relevance feedback mechanism for cluster-based retrieval     

Niall Rooney  David Patterson  Mykola Galushka  Vladimir Dobrynin 《Information processing & management》2006

Contextual document clustering is a novel approach which uses information theoretic measures to cluster semantically related documents bound together by an implicit set of concepts or themes of narrow specificity. It facilitates cluster-based retrieval by assessing the similarity between a query and the cluster themes’ probability distribution. In this paper, we assess a relevance feedback mechanism, based on query refinement, that modifies the query’s probability distribution using a small number of documents that have been judged relevant to the query. We demonstrate that by providing only one relevance judgment, a performance improvement of 33% was obtained.  相似文献   

Um Compasso Para Aprender: A Randomized Trial of a Social-Emotional Learning Program in Homicide-Affected Communities in Brazil     

Dana C. McCoy  Emily C. Hanno  Vladimir Ponczek  Cristine Pinto  Gabriela Fonseca  Natália Marchi 《Child development》2021,92(5):1951-1968

Despite global demand, the large-scale effects of social-emotional learning (SEL) programming in developing countries remain underexplored. Using a randomized control trial, this study examined the effectiveness of a school-wide SEL intervention—Programa Compasso (PC)—among 3,018 sociodemographically diverse, Portuguese-speaking children (M_age = 9.85 years) attending 90 public primary schools across Rio de Janeiro, Brazil in 2017. Average impacts of PC on children’s executive function, emotion knowledge, and behavior problems after one school year were null. Moderation analyses did, however, reveal evidence for positive impacts of PC on children’s labeling of emotional expressions and inhibitory control within low-homicide communities (d = 0.15 SDs), and null effects on these same outcomes in high-violence areas. Implementation and cultural considerations are discussed.  相似文献   

Space Scale: Models in the History of Science and Students Mental Models     

Josef Feigenberg  Lea Valentina Lavrik  Vladimir Shunyakov 《Science & Education》2002,11(4):377-392

This paper deals with the problem of relating distance and scale by way of alternative models of perception taken from the history of science.The intuitive patterns of modern school children in evaluating the Solar System are then compared with those in the history of science. Immediate experience and intuition by children often contradict scientific understanding. The children in this study, for example, do not see the rays of the Sun as being parallel and ignore the curvature of the Earth. The authors argue that children's understanding of the rays of the Sun as not being parallel as well as their ignoring the curvature of the Earth is due to the limitation resulting from the students' `actual activity zone', and not to their insufficient knowledge. This study makes specific suggestions to broaden the scientifically based `actual activity zone' of students. We suggest that laboratory work based on historical experiments using elementary geometry – as, for example, the determination of the radiusof the Earth by Eratosthenes – promotes a scientific understanding of astronomicalmeasurements....The scale of space and time, which we customarily observe on Earth, and which is part of time, we become aware of the vastness of our universe, we are awed and humbled. But if astronomers spent all their time speculating about the immensity of the cosmos and the prodigious interval of time necessary for the evolution of the stars, their accomplishments would be few. The primary concerns of the astronomer when studying the cosmos are physical and mathematical interpretations of observations, predictions of future observations, and the development and refinement of his instruments for such interpretation and prediction. To help him in the conceptualization of his problem, astronomer may, consciously or unconsciously, visualize a small model representing the cosmic system under investigation. Using this method, we can arrive at an understanding of the relative dimensions of the system and an understanding of the time intervals involved.Shklovskii I.S. and Carl Sagan (1966)Intelligent Life in the Universe  相似文献   

When induction meets memory: evidence for gradual transition from similarity-based to category-based induction   总被引：3，自引：0，他引：3  

Fisher AV  Sloutsky VM 《Child development》2005,76(3):583-597

The ability to perform induction appears early; however, underlying mechanisms remain unclear. Some argue that early induction is category based, whereas others suggest that early induction is similarity based. Category- and similarity-based induction should result in different memory traces and thus in different memory accuracy. Performing induction resulted in low memory accuracy in adults and 11-year-olds, whereas 5-, and 7-year-olds were highly accurate (Experiment 1). After training to perform category-based induction, 5- and 7-year-olds exhibited patterns of accuracy similar to those of adults (Experiment 2). Furthermore, 7-year-olds, but not 5-year-olds, retained this training over time (Experiment 3). With novel categories, even adults performed similarity-based induction, exhibiting high memory accuracy (Experiment 4). These results suggest a gradual transition from similarity- to category-based induction with familiar categories.  相似文献   

Maris: A knowledge system for internal medicine     

Vladimir Slamecka  Henry N. Camp  Albert N. Badre  W. Dallas Hall 《Information processing & management》1977,13(5):273-276

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Preface     

Vladimir Slamecka  Harold Borko 《Information processing & management》1980,16(4-5)

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硅酸盐-盐（硫酸盐）流体不混溶：蒙古南部Mushugai-Khuduk含火成碳酸岩杂岩体矿物中的熔体包裹体研究     

IrinaA.Andreeva Vyacheslav I.Kovalenko Vladimir B.Naumov 《中国科技期刊研究》2007,23(1):73-82

Crystalline and melt inclusions were studied in garnet, diopside, potassium feldspar, and sphene from the garnet syenite porphyry of the carbonatite-bearing complex Mushugai-Khuduk, southern Mongolia. Phlogopite, clinopyroxene, albite, potassium feldspar, sphene, wollastonite, magnetite, Ca and Sr sulfates, fluorite, and apatite were identified among the crystalline inclusions. The melt inclusions were homogenized at 1010℃～1080℃ and analyzed on an electron microprobe. Silicate, salt, and combined silicate-salt melt inclusions were found. Silicate melts show considerable variations in SiO2 concentration （56 to 66wt% ）, high Na2O ＋ K20 （up to 17wt% ）, and elevated Zr, F, and Cl contents. In terms of bulk rock chemistry, the silicate melts are alkali syenites. During thermometric experiments, salt melt inclusions quenched into homogeneous glasses of predominantly sulfate compositions containing no more than 1.3wt% SiO2. These melts are enriched in alkalis, Ba, Sr, P, F, and Cl. The investigation of the silicate and salt melt inclusions in minerals of the garnet syenite porphyries indicate that these rocks were formed under influence of the processes of crystallization differentiation and magma separation into immiscible silicate and salt （sulfate）liquids.  相似文献   

The effects of adult literacy on earnings and employment     

Maúna Soares de Baldini Rocha Vladimir Ponczek 《Economics of Education Review》2011,30(4):755-764

This paper provides evidence of the effects of adult literacy on individuals’ income and employability in Brazil based on information obtained from the monthly employment survey (PME). The OLS results indicate that after controlling for observable characteristics, there is a 21.25% increase in wages for individuals who become literate; however, there is no significant impact on employability. Moreover, the findings show an 8.1% increase in the probability of being employed in the formal sector. We also explore the longitudinal structure of the dataset to control for unobservable fixed characteristics of individuals. The fixed-effects estimators show smaller effects compared to the OLS estimators. We find that literacy has a 4.4% effect on wages and a 4.3% impact on the probability of being formally employed. The effects are significantly different from zero.  相似文献   

Fluid balance and hydration assessment during the weight-stable preparation phase in elite youth boxers     

Damir Zubac  Tomislav Antelj  Dragana Olujic  Vladimir Ivancev  Shawnda A. Morrison 《Journal of sports sciences》2017,35(8):719-726

This study investigated (i) the prevalence of hypohydration and (ii) association between urinary indices of hydration status and confounding factors (e.g., urine protein content, water intake) in elite youth boxers during their weight-stable phase before competition. Sixteen national champion boxers (all male, 17 ± 1 y) were measured on 3 occasions (baseline, day 3, day 10), 30-day prior to competition. Body mass, total body water, urine specific gravity (USG), osmolality (UOSM) and total protein content (TPC) were evaluated to determine hydration status and fluid balance. Overall macronutrient and water intake were assessed using dietary records. Both UOSM and USG increased from day 3 to day 10 by 16% and 0.4% (P < 0.001), despite athletes being in their weight-stability period, and regardless of ad libitum fluid intake. Hypohydration was universally prevalent among all athletes on both test days with USG: 1.027 ± 0.003 g · mL^?1 and UOSM: 1035 ± 108 mOsmol · kg^?1. An inverse association between mean UOSM values and mean water intake was observed (R = ?0.52, P = 0.04), while TPC was not associated with any urinary dehydration markers (USG, P = 0.51; UOSM, P = 0.61). The present outcomes find that the most prevalent urinary dehydration markers used to classify hydration status in competition exhibit large variability, even during weight-stable periods.  相似文献   

New developments in teacher education in the United States     

Maureen T. Hallinan  Vladimir T. Khmelkov 《Irish Educational Studies》2013,32(1):369-396

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