1,012 research outputs found

    Calorimetric study of the thermodynamic properties of the nickel-cadmium cell Final report, 1 Oct. 1964 - 31 Dec. 1965

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    Thermal properties of electrochemical cells from calorimetry of nickel-cadmium batter

    Teleoperation experiments with a Utah/MIT hand and a VPL DataGlove

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    A teleoperation system capable of controlling a Utah/MIT Dextrous Hand using a VPL DataGlove as a master is presented. Additionally the system is capable of running the dextrous hand in robotic (autonomous) mode as new programs are developed. The software and hardware architecture used is presented and the experiments performed are described. The communication and calibration issues involved are analyzed and applications to the analysis and development of automated dextrous manipulations are investigated

    Virtual Manipulatives Used by K-8 Teachers for Mathematics Instruction: Considering Mathematical, Cognitive, and Pedagogical Fidelity

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    This study examined teachers’ uses of virtual manipulatives across grades K-8 after participating in a professional development institute in which manipulatives and technology were the major resources used throughout all of the activities. Researchers analyzed 95 lesson summaries in which classroom teachers described their uses of virtual manipulatives during school mathematics instruction. The findings indicated that the content in a majority of the lessons focused on two National Council of Teachers of Mathematics (2000a) standards: Number & Operations and Geometry. Virtual geoboards, pattern blocks, base-10 blocks, and tangrams were the applets used most often by teachers. The ways teachers used the virtual manipulatives most frequently focused on investigation and skill solidification. It was common for teachers to use the virtual manipulatives alone or to use physical manipulatives first, followed by virtual manipulatives. One important finding of this study was that teachers used the virtual manipulatives during the main portion of their lessons when students were learning mathematics content. These results represent an initial exploration of teachers’ current use of virtual manipulatives in K-8 classrooms

    On the average density profile of dark-matter halos in the inner regions of massive early-type galaxies

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    We study a sample of 39 massive early-type lens galaxies at redshift z < 0.3 to determine the slope of the average dark-matter density profile in the innermost regions. We keep the strong lensing and stellar population synthesis modeling as simple as possible to measure the galaxy total and luminous masses. By rescaling the values of the Einstein radius and dark-matter projected mass with the values of the luminous effective radius and mass, we combine all the data of the galaxies in the sample. We find that between 0.3 and 0.9 times the value of the effective radius the average logarithmic slope of the dark-matter projected density profile is -1.0 +/- 0.2 (i.e., approximately isothermal) or -0.7 +/- 0.5 (i.e., shallower than isothermal), if, respectively, a constant Chabrier or heavier, Salpeter-like stellar IMF is adopted. These results provide positive evidence of the influence of the baryonic component on the contraction of the galaxy dark-matter halos, compared to the predictions of dark matter-only cosmological simulations, and open a new way to test models of structure formation and evolution within the standard LCDM cosmological scenario.Comment: 5 pages, 2 figures, published in Astrophysical Journal Letters 747, L1

    Ein Beitrag zur Kenntniss der Benzoeharze

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    http://tartu.ester.ee/record=b2289096~S1*es

    Coding Variables

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    http://deepblue.lib.umich.edu/bitstream/2027.42/116265/1/cv04.pd

    Measuring the Haptic Perception of Leather Surfaces

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    Products on today’s markets are technically mature. A differentiation by conventional criteria is increasingly difficult or even impossible for the customers. Subjectively influenced factors replace clearly defined technical attributes as criteria for differentiation. Therefore it is necessary for manufacturers to identify those product characteristics which are perceived by the customers and influence their quality rating. This paper presents a sensory method to detect the customers’ haptic evaluation and rating of leather and artificial leather surfaces. These customer requirements and ratings can systematically be linked to measurable technical parameters and communicated and controlled during the product development process

    Analysis of United Kingdom Off-Highway Construction Machinery Market and Its Consumers Using New-Sales Data

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    The off-highway construction machinery market and its consumers have attracted minimal previous research. This study addresses that void by analyzing annual United Kingdom (UK) (volume/portfolio) new-sales data for the 10 most popular products within that market, 1990–2010 inclusive. Graphical, descriptive statistical, Pearson-correlational, autocorrelational, and elementary modeling are employed to identify contrasts in sales regarding (1) high- and low-volume items; (2) growth trends and significant recessionary effects on volumes; (3) a demand change point circa 1997, since when annual product portfolio has changed little; and (4) product associations in consumer demand. Significant association is demonstrated between demand and construction output, especially with the value of new housing. Subsequently, consumption of wheeled loaders is modeled using construction volume, and demand for mini and crawler excavators is modeled using new-housing data. Time series trends for these machinery types are presented and forecast through 2015. The primary contribution of this study is a deeper understanding of the UK new-machinery market and the predilections of its consumers over the last two decades (to present)
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