20,001 research outputs found
The Effects of JIT on the Development of Productivity Norms
Low inventory, or just-in-time (JIT) manufacturing systems, enjoy increasing application worldwide, yet the behavioral effects of such systems remain largely unexplored. Operations Research (OR) models of low inventory systems typically make a simplifying assumption that individual worker processing times are independent random variables. This leads to predictions that low-inventory systems will exhibit production interruptions. Yet empirical results suggest that low-inventory systems do not exhibit the predicted productivity losses. This paper develops a model integrating feedback, goal-setting, group cohesiveness, task norms, and peer pressure to predict how individual behavior may adjust to alleviate production interruptions in low-inventory systems. In doing so we integrate previous research on the development of task norms. Findings suggest that low-inventory systems induce individual and group responses that cause behavioral changes that mitigate production interruptions
Discovery of meteorites on a blue-ice field near the Frontier Mountains, North Victoria Land, Antarctica
A high concentration of meteorites were discovered on a blue ice field northeast of the Frontier Mountains. As a result of a systematic search, a total of 42 meteorites were recovered. The current glacial situation has evolved through various stages, which are discussed in relationship to the concentration of meteorites. Ice flow patterns are summarized. The chemical composition and terrestrial ages of the meteorites are discussed
The design of linear multivariable control systems using modern control theory /with applications to coupled core reactor control/
Linear multivariable control system design using modern control theory, and application to coupled core reactor contro
Domain structure of epitaxial Co films with perpendicular anisotropy
Epitaxial hcp Cobalt films with pronounced c-axis texture have been prepared
by pulsed lased deposition (PLD) either directly onto Al2O3 (0001) single
crystal substrates or with an intermediate Ruthenium buffer layer. The crystal
structure and epitaxial growth relation was studied by XRD, pole figure
measurements and reciprocal space mapping. Detailed VSM analysis shows that the
perpendicular anisotropy of these highly textured Co films reaches the
magnetocrystalline anisotropy of hcp-Co single crystal material. Films were
prepared with thickness t of 20 nm < t < 100 nm to study the crossover from
in-plane magnetization to out-of-plane magnetization in detail. The analysis of
the periodic domain pattern observed by magnetic force microscopy allows to
determine the critical minimum thickness below which the domains adopt a pure
in-plane orientation. Above the critical thickness the width of the stripe
domains is evaluated as a function of the film thickness and compared with
domain theory. Especially the discrepancies at smallest film thicknesses show
that the system is in an intermediate state between in-plane and out-of-plane
domains, which is not described by existing analytical domain models
First results of the two square meters multilayer glass composite mirror design proposed for the Cherenkov Telescope Array developed at INFN
The Cherenkov Telescope Array (CTA) is a future ground-based gamma-ray
astronomy detector that will consist of more than 100 Imaging Atmospheric
Cherenkov Telescopes of different sizes. The total reflective surface of
roughly 10 000 m requires unprecedented technological efforts towards a
cost-efficient production of light-weight and reliable mirror substrates at
high production rate. We report on a new mirror concept proposed for CTA
developed by INFN, which is based on the replication from a spherical convex
mold under low pressure. The mirror substrate is an open structure design made
by thin glass layers at the mirror's front and rear interspaced by steel
cylinders. A first series of nominal size mirrors has been produced, for which
we discuss the optical properties in terms of radius of curvature and focusing
power
Monopolelike probes for quantitative magnetic force microscopy: calibration and application
A local magnetization measurement was performed with a Magnetic Force
Microscope (MFM) to determine magnetization in domains of an exchange coupled
[Co/Pt]/Co/Ru multilayer with predominant perpendicular anisotropy. The
quantitative MFM measurements were conducted with an iron filled carbon
nanotube tip, which is shown to behave like a monopole. As a result we
determined an additional in-plane magnetization component of the multilayer,
which is explained by estimating the effective permeability of the sample
within the \mu*-method.Comment: 3 pages, 3 figure
A 'p-n' diode with hole and electron-doped lanthanum manganite
The hole-doped manganite La0.7Ca0.3MnO3 and the electron-doped manganite
La0.7Ce0.3MnO3 undergo an insulator to metal transition at around 250 K, above
which both behave as a polaronic semiconductor. We have successfully fabricated
an epitaxial trilayer (La0.7Ca0.3MnO3/SrTiO3/La0.7Ce0.3MnO3), where SrTiO3 is
an insulator. At room temperature, i.e. in the semiconducting regime, it
exhibits asymmetric current-voltage (I-V) characteristics akin to a p-n diode.
The observed asymmetry in the I-V characteristics disappears at low
temperatures where both the manganite layers are metallic. To the best of our
knowledge, this is the first report of such a p-n diode, using the polaronic
semiconducting regime of doped manganites.Comment: PostScript text and 2 figures, to be published in Appl. Phys. Lett
THE GEOLOGY AND MAMMALIAN FAUNA OF THE PLEISTOCENE OF NEBRASKA PART I OUTLINE OF PLEISTOCENE GEOLOGY OF NEBRASKA PART II THE PLEISTOCENE MAMMALS OF NEBRASKA
The object of the present paper is to provide a suitable brief statement of the present state of knowledge of the Pleistocene geology of Nebraska, for an adequate understanding of the Pleistocene Mammal list, by Mr. C. Bertrand Schultz, which forms Part II of this report. The outline is necessarily brief and does not contain many detailed sections, nor lengthy discussions of controversial points. It is lacking in adequate detailed descriptions of new formations and may not be entirely convincing to many readers. The only excuse which the writer can offer for the shortcomings of the following pages is the necessity for brevity, and so the presentation is little more than a statement of conclusions
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