55,568 research outputs found

    A control chart procedure for student grade monitoring

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    This article reports an application of the control chart procedure for monitoring award of grades to students by the teaching staff in a large university. The chart procedure signals the presence of special cause variations if any in the award of grades. Implementation of the grade monitoring procedure saved considerable time and effort while ensuring that the reported special cause situations are justified. The mathematical derivations for the new control chart scheme are also presented

    Depriming of arterial heat pipes: An investigation of CTS thermal excursions

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    Four thermal excursions of the Transmitter Experiment Package (TEP) were the result of the depriming of the arteries in all three heat pipes in the Variable Conductance Heat Pipe System which cooled the TEP. The determined cause of the depriming of the heat pipes was the formation of bubbles of the nitrogen/helium control gas mixture in the arteries during the thaw portion of a freeze/thaw cycle of the inactive region of the condenser section of the heat pipe. Conditions such as suction freezeout or heat pipe turn-on, which moved these bubbles into the active region of the heat pipe, contributed to the depriming mechanism. Methods for precluding, or reducing the probability of, this type of failure mechanism in future applications of arterial heat pipes are included

    Computer program grade 2 for the design and analysis of heat-pipe wicks

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    This user's manual describes the revised version of the computer program GRADE(1), which designs and analyzes heat pipes with graded porosity fibrous slab wicks. The revisions are: (1) automatic calculation of the minimum condenser-end stress that will not result in an excess-liquid puddle or a liquid slug in the vapor space; (2) numerical solution of the equations describing flow in the circumferential grooves to assess the burnout criterion; (3) calculation of the contribution of excess liquid in fillets and puddles to the heat-transport; (4) calculation of the effect of partial saturation on the wick performance; and (5) calculation of the effect of vapor flow, which includes viscousinertial interactions

    Far-infrared reflectance of spacecraft coatings

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    Far infrared reflectance and transmittance as function of wavelength for spacecraft coating

    Expert systems for real-time monitoring and fault diagnosis

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    Methods for building real-time onboard expert systems were investigated, and the use of expert systems technology was demonstrated in improving the performance of current real-time onboard monitoring and fault diagnosis applications. The potential applications of the proposed research include an expert system environment allowing the integration of expert systems into conventional time-critical application solutions, a grammar for describing the discrete event behavior of monitoring and fault diagnosis systems, and their applications to new real-time hardware fault diagnosis and monitoring systems for aircraft

    Overlap Fermions on a 20420^4 Lattice

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    We report results on hadron masses, fitting of the quenched chiral log, and quark masses from Neuberger's overlap fermion on a quenched 20420^4 lattice with lattice spacing a=0.15a = 0.15 fm. We used the improved gauge action which is shown to lower the density of small eigenvalues for H2H^2 as compared to the Wilson gauge action. This makes the calculation feasible on 64 nodes of CRAY-T3E. Also presented is the pion mass on a small volume (63×126^3 \times 12 with a Wilson gauge action at β=5.7\beta = 5.7). We find that for configurations that the topological charge Q≠0Q \ne 0, the pion mass tends to a constant and for configurations with trivial topology, it approaches zero possibly linearly with the quark mass.Comment: Lattice 2000 (Chiral Fermion), 4 pages, 4 figure
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