1,300 research outputs found

    The Comparative Correlative Construction in Modern Standard Arabic

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    Much discussion of the comparative correlative construction exemplified by The more I read, the more I understand has been concerned with how much cross?linguistic variation there is in this area. Culicover and Jackendoff (1999) suggest that there is considerable variation, but Den Dikken (2005) suggests with data from a variety of languages that the variation is quite limited. Modern Standard Arabic has a comparative correlative construction which is quite different from Engish and the other languages that Den Dikken considers, suggesting that there is more variation in this domain than he assumes. However, it is not difficult to provide an analysis of the construction and other related constructions within the HPSG framework

    Browsing and book selection in the physical library shelves

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    Library users should be conveniently interact with collections and be able to easily choose books of interest as they explore and browse a physical book collection. While there exists a growing body of naturalistic studies of browsing and book selection in digital collections, the corresponding literature on behaviour in the physical stacks is surprisingly sparse. We add to this literature in this paper, by conducting observations of patrons in a university library as they selected books from the shelves. Our aim is to further our understanding of patterns of behaviour in browsing and selection in physical collections

    Clustering ensemble method

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    A clustering ensemble aims to combine multiple clustering models to produce a better result than that of the individual clustering algorithms in terms of consistency and quality. In this paper, we propose a clustering ensemble algorithm with a novel consensus function named Adaptive Clustering Ensemble. It employs two similarity measures, cluster similarity and a newly defined membership similarity, and works adaptively through three stages. The first stage is to transform the initial clusters into a binary representation, and the second is to aggregate the initial clusters that are most similar based on the cluster similarity measure between clusters. This iterates itself adaptively until the intended candidate clusters are produced. The third stage is to further refine the clusters by dealing with uncertain objects to produce an improved final clustering result with the desired number of clusters. Our proposed method is tested on various real-world benchmark datasets and its performance is compared with other state-of-the-art clustering ensemble methods, including the Co-association method and the Meta-Clustering Algorithm. The experimental results indicate that on average our method is more accurate and more efficient

    Open-Circuit Voltage in Inverted Polycarbazole:Fullerene Bulk Heterojunction Solar Cells

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    The correlation between cathode work function and open-circuit voltages (Voc) in inverted polycarbazole:fullerene (PCDTBT:PC70BM) bulk-heterojunction solar cells has been investigated by postannealing of indium tin oxide (ITO) electrodes. The ITO function is seen to change from 4.2 to 4.5 eV without the need to insert additional interfacial layers with annealing temperature up to 400 °C. The best device performance was obtained at room temperature with the ITO work function of 4.2 eV with a Voc of 0.89 eV, a Jsc of 8.06 mA·cm-2, a fill factor (FF) of 64.70%, and a power conversion efficiency of 4.62%. Together with previously published results, we are able to extract two regimes of Voc dependence on the cathode work function: first, a linear relationship when the cathode work function exceeds the lowest unoccupied molecular orbital (LUMO) of PCBM and, second, a constant Voc regime when the ITO work function reduces below the LUMO level. These results provide general guidelines for the cathode contact design in inverted polymer solar cells

    An Arabidopsis thaliana leucine-rich repeat protein harbors an adenylyl cyclase catalytic center and affects responses to pathogens

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    Adenylyl cyclases (ACs) catalyze the formation of the second messenger cAMP from ATP. Here we report the characterization of an Arabidopsis thaliana leucine-rich repeat (LRR) protein (At3g14460; AtLRRAC1) as an adenylyl cyclase. Using an AC-specific search motif supported by computational assessments of protein models we identify an AC catalytic center within the N-terminus and demonstrate that AtLRRAC1 can generate cAMP in vitro. Knock-out mutants of AtLRRAC1 have compromised immune responses to the biotrophic fungus Golovinomyces orontii and the hemibiotrophic bacteria Pseudomonas syringae, but not against the necrotrophic fungus Botrytis cinerea. These findings are consistent with a role of cAMP-dependent pathways in the defense against biotrophic and hemibiotrophic plant pathogens

    Thermally stable solution processed vanadium oxide as a hole extraction layer in organic solar cells

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    Low-temperature solution-processable vanadium oxide (V2Ox) thin films have been employed as hole extraction layers (HELs) in polymer bulk heterojunction solar cells. V2Ox films were fabricated in air by spin-coating vanadium(V) oxytriisopropoxide (s-V2Ox) at room temperature without the need for further thermal annealing. The deposited vanadium(V) oxytriisopropoxide film undergoes hydrolysis in air, converting to V2Ox with optical and electronic properties comparable to vacuum-deposited V2O5. When s-V2Ox thin films were annealed in air at temperatures of 100 °C and 200 °C, OPV devices showed similar results with good thermal stability and better light transparency. Annealing at 300 °C and 400 °C resulted in a power conversion efficiency (PCE) of 5% with a decrement approximately 15% lower than that of unannealed films; this is due to the relative decrease in the shunt resistance (Rsh) and an increase in the series resistance (Rs) related to changes in the oxidation state of vanadium

    AN EXPLORATORY STUDY TO IDENTIFY TEACHING STYLES IN SAUDI ARABIA BASED ON THREE LEARNING THEORIES

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    The purpose of this quantitative study was to investigate Saudi teachers’ philosophy in teaching based on three major learning theories (behaviorism, cognitivism, and constructivism).  Also, it showed the different between gender (male, female), and teachers’ experiences in teaching (1-5, 6-10, 11-15, 16-20, more than 20 years), and level of teaching (Elementary, Middle, and High) school in the preferred teaching philosophy. The result showed that Saudis’ teacher proffered using cognitivism philosophy more than constructivism philosophy and behaviorism philosophy. Although the male teacher had preferred behaviorism school more than female teachers, the female teachers had preferred cognitivism and constructivism schools more than male teachers. Also, the teachers who had more experience preferred cognitivism and constructivism schools more than behaviorism school
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