638 research outputs found

    A spectral collocation technique based on integrated Chebyshev polynomials for biharmonic problems in irregular domains

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    In this paper, an integral collocation approach based on Chebyshev polynomials for numerically solving biharmonic equations [N. Mai-Duy, R.I. Tanner, A spectral collocation method based on integrated Chebyshev polynomials for biharmonic boundary-value problems, J. Comput. Appl. Math. 201 (1) (2007) 30–47] is further developed for the case of irregularly shaped domains. The problem domain is embedded in a domain of regular shape, which facilitates the use of tensor product grids. Two relevant important issues, namely the description of the boundary of the domain on a tensor product grid and the imposition of double boundary conditions, are handled effectively by means of integration constants. Several schemes of the integral collocation formulation are proposed, and their performances are numerically investigated through the interpolation of a function and the solution of 1D and 2D biharmonic problems. Results obtained show that they yield spectral accuracy

    Diverse assessment methods in group work settings

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    The assessment scheme and mid-course feedback play a central role in the student's learning experience. However, within the student population there are many different perceptions of teaching and learning, and to accommodate these a diverse range of assessment and feedback activites are required. This issue is particularly important when group-orientated problem-based learning is employed, since much of the learning occurs within the groups and away from the direct supervision of the unit coordinators. We have explored a range of assessment styles in a suite of units of study in second year chemical engineering, centred around group-based project work. Group written project reports, interviews, confidential self and peer-assessments, individual laboratory reports, quizzes and a final examination have been used so far. Alignment of these assessments and teaching & learning activities with the learning outcomes guided our development of this framework, and this alignment has been verified by the students' results. The projects themselves are open-ended and present realistic engineering scenarios, including recommending the best type of artificial heart, the overall design of a desalination plant, and the design of a soap and cosmetics factory. A high level of student engagement and enthusiasm for the project work has been observed, arising mainly from the real-world nature of the projects, coupled with the stimuli provided by the range of assessment activities used

    What Remains: Pseudotranslation as Salvage

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    Pseudotranslations are literary works which purport to be translations of lost or suppressed originals, i.e. to be ‘salvaged’ from oblivion or obscurity. Pseudotranslation has attracted a good deal of attention within translation studies in recent years, but as a practice it can be traced back a long way. This article discusses a number of examples of the type, from Cervantes’ Don Quixote and modern works treating Shakespeare as pseudotranslated (Star Trek VI, Tom Stoppard’s Arcadia) through notable eighteenth-century examples (Walpole’s The Castle of Otranto, MacPherson’s Ossian) to non-fictional fictions The Book of Mormon and ‘Nietzsche’s’ fraudulent late autobiography My Sister and I. Readers of translations usually trust that an original exists, and pseudotranslations abuse that trust. But even when an original does exist, translation performs a kind of salvage operation, acting as a kind of lifeboat which rescues a text from the passing of time and keeps it afloat for posterity

    Tradable Pollution Permits and the Regulatory Game

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    This paper analyzes polluters\u27 incentives to move from a traditional command and control (CAC) environmental regulatory regime to a tradable permits (TPP) regime. Existing work in environmental economics does not model how firms contest and bargain over actual regulatory implementation in CAC regimes, and therefore fail to compare TPP regimes with any CAC regime that is actually observed. This paper models CAC environmental regulation as a bargaining game over pollution entitlements. Using a reduced form model of the regulatory contest, it shows that CAC regulatory bargaining likely generates a regulatory status quo under which firms with the highest compliance costs bargain for the smallest pollution reductions, or even no reduction at all. As for a tradable permits regime, it is shown that all firms are better off under such a regime than they would be under an idealized CAC regime that set and enforced a uniform pollution standard, but permit sellers (low compliance cost firms) may actually be better off under a TPP regime with relaxed aggregate pollution levels. Most importantly, because high cost firms (or facilities) are the most weakly regulated in the equilibrium under negotiated or bargained CAC regimes, they may be net losers in a proposed move to a TPP regime. When equilibrium costs under a TPP regime are compared with equilibrium costs under a status quo CAC regime, several otherwise paradoxical aspects of firm attitudes toward TPP type reforms can be explained. In particular, the otherwise paradoxical pattern of allowances awarded under Phase II of the 1990 Clean Air Act\u27s acid rain program, a pattern tending to favor (in Phase II) cleaner, newer generating units, is explained by the fact that under the status quo regime, a kind of bargained CAC, it was the newer cleaner units that were regulated, and which therefore had higher marginal control costs than did the largely unregulated older, plants. As a normative matter, the analysis here implies that the proper baseline for evaluating TPP regimes such as those contained in the Bush Administration\u27s recent Clear Skies initiative is not idealized, but nonexistent CAC regulatory outcomes, but rather the outcomes that have resulted from the bargaining game set up by CAC laws and regulations

    Mixed Wino Dark Matter: Consequences for Direct, Indirect and Collider Detection

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    In supersymmetric models with gravity-mediated SUSY breaking and gaugino mass unification, the predicted relic abundance of neutralinos usually exceeds the strict limits imposed by the WMAP collaboration. One way to obtain the correct relic abundance is to abandon gaugino mass universality and allow a mixed wino-bino lightest SUSY particle (LSP). The enhanced annihilation and scattering cross sections of mixed wino dark matter (MWDM) compared to bino dark matter lead to enhanced rates for direct dark matter detection, as well as for indirect detection at neutrino telescopes and for detection of dark matter annihilation products in the galactic halo. For collider experiments, MWDM leads to a reduced but significant mass gap between the lightest neutralinos so that chi_2^0 two-body decay modes are usually closed. This means that dilepton mass edges-- the starting point for cascade decay reconstruction at the CERN LHC-- should be accessible over almost all of parameter space. Measurement of the m_{\tz_2}-m_{\tz_1} mass gap at LHC plus various sparticle masses and cross sections as a function of beam polarization at the International Linear Collider (ILC) would pinpoint MWDM as the dominant component of dark matter in the universe.Comment: 29 pages including 19 eps figure

    Method and System for Weakening Shock Wave Strength at Leading Edge Surfaces of Vehicle in Supersonic Atmospheric Flight

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    A method and system are provided to weaken shock wave strength at leading edge surfaces of a vehicle in atmospheric flight. One or more flight-related attribute sensed along a vehicle's outer mold line are used to control the injection of a non-heated, non-plasma-producing gas into a local external flowfield of the vehicle from at least one leading-edge surface location along the vehicle's outer mold line. Pressure and/or mass flow rate of the gas so-injected is adjusted in order to cause a Rankine-Hugoniot Jump Condition along the vehicle's outer mold line to be violated

    Direct, Indirect and Collider Detection of Neutralino Dark Matter In SUSY Models with Non-universal Higgs Masses

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    In supersymmetric models with gravity-mediated SUSY breaking, universality of soft SUSY breaking sfermion masses m_0 is motivated by the need to suppress unwanted flavor changing processes. The same motivation, however, does not apply to soft breaking Higgs masses, which may in general have independent masses from matter scalars at the GUT scale. We explore phenomenological implications of both the one-parameter and two-parameter non-universal Higgs mass models (NUHM1 and NUHM2), and examine the parameter ranges compatible with Omega_CDM h^2, BF(b --> s,gamma) and (g-2)_mu constraints. In contrast to the mSUGRA model, in both NUHM1 and NUHM2 models, the dark matter A-annihilation funnel can be reached at low values of tan(beta), while the higgsino dark matter annihilation regions can be reached for low values of m_0. We show that there may be observable rates for indirect and direct detection of neutralino cold dark matter in phenomenologically aceptable ranges of parameter space. We also examine implications of the NUHM models for the Fermilab Tevatron, the CERN LHC and a Sqrt(s)=0.5-1 TeV e+e- linear collider. Novel possibilities include: very light s-top_R, s-charm_R squark and slepton_L masses as well as light charginos and neutralinos and H, A and H^+/- Higgs bosons.Comment: LaTeX, 48pages, 26 Figures. The version with high resolution Figures is available at http://hep.pa.msu.edu/belyaev/public/projects/nuhm/nuhm.p
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