5,246 research outputs found

    Estimation of an Examinee's Ability in the Web-Based Computerized Adaptive Testing Program IRT-CAT

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    We developed a program to estimate an examinee s ability in order to provide freely available access to a web-based computerized adaptive testing (CAT) program. We used PHP and Java Script as the program languages, PostgresSQL as the database management system on an Apache web server and Linux as the operating system. A system which allows for user input and searching within inputted items and creates tests was constructed. We performed an ability estimation on each test based on a Rasch model and 2- or 3-parametric logistic models. Our system provides an algorithm for a web-based CAT, replacing previous personal computer-based ones, and makes it possible to estimate an examinee's ability immediately at the end of test

    Enhanced light harvesting in bulk heterojunction photovoltaic devices with shape-controlled Ag nanomaterials: Ag nanoparticles versus Ag nanoplates

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    Enhanced power conversion efficiency (PCE(%)) with improved optical path length from two types of shape controlled silver (Ag) materials (Ag nanoplates versus Ag nanoparticles (NPs)) was studied in poly(3-hexylthiophene) (P3HT)/[6,6]-phenyl C 71 butyric acid methyl-ester (PC 71BM) or poly[N-9′′-hepta-decanyl-2,7-carbazole-alt-5,5-(4′, 7′-di-2-thienyl-2′,1′,3′-benzothiadiazole)] (PCDTBT)/[6,6]-phenyl C 71 butyric acid methyl-ester (PC 71BM) bulk heterojunction (BHJ) devices. The Ag nanoplates and Ag NPs can be synthesized by simple solution polyol chemistry with well defined size and shape. A BHJ with a 0.5 wt% optimized blend ratio of Ag nanoplates shows improved cell performance and photo-current density than a BHJ with Ag NPs owing to the enhanced light absorption with the results of an excitation of localized surface plasmon and efficient light scattering by the Ag nanoplates embedded BHJ film. When the BHJ is combined with the Ag nanoplates at an optimized ratio of 0.5 wt%, the PCE (%) increases from 3.2% to 4.4% in P3HT/PC 71BM, and from 5.9% to 6.6% in PCDTBT/PC 71BM BHJ devices. © 2012 The Royal Society of Chemistry.1

    Mental Imagery in an In-store Apparel Shopping Context: Do Women and Men Differ?

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    This study examined how mental imagery experienced during in-store shopping influences consumers’ affective (anticipatory emotion), cognitive (perceived ownership and decision satisfaction) responses and conative response (behavioral intentions) and further investigated how men and women differ in the way mental imagery influences consumer responses
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