146,403 research outputs found

    A Reflective Evaluation of Group Assessment

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    There is a general agreement in the literature that groupwork helps to develop important interpersonal and personal skills (Race, 2001; Visram & Joy, 2003; Elliot & Higgins, 2005; Kench et al, 2008). However, one of the problems with groupwork for both students and lecturers is how the work should be assessed (Parsons & Kassabova, 2002). The possibility of having ‘free-riders’ and the difficulty of fairly awarding marks to reflect the level of students’ contribution to a group output are some of the key problem areas in groupwork assessment (Race, 2001). Peer assessment is seen as one of the methods to deal with these problems. It can generally involve students assessing each other’s level of contribution to the group’s output (Visram & Joy, 2003). This paper provides our reflection on the use of peer assessment on a student group project

    A taxonomic revision of Camptocerus Dejean (Coleoptera: Curculionidae: Scolytinae)

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    The Neotropical ambrosia beetle genus Camptocerus Dejean was revised. Monophyly of the genus was tested using 66 morphological characters in a cladistic analysis. Camptocerus was recovered as monophyletic and 31 species were recognized. Six new synonyms were discovered: C. auricomus Blandford 1896 (= C. striatulus Hagedorn 1905), C. inoblitus (Schedl) 1939 (= C. morio (Schedl) 1952), C. niger (Fabricius) 1801 (= C. tectus Eggers 1943), C. opacicollis (Eggers) 1929 (= C. infidelis Wood 1969; = C. uniseriatus Schedl 1972), C. suturalis (Fabricius) 1801 (= C. cinctus Chapuis 1869). Two species were removed from synonymy: C. charpentierae Schedl and C. hirtipennis Schedl. Twelve new species of Camptocerus were described: C. coccoformus (Brazil, Ecuador), C. distinctus (Ecuador), C. doleae (Ecuador), C. igniculus (Brazil), C. mallopterus (Ecuador), C. noel (widely distributed across Amazonia), C. petrovi (Ecuador), C. pilifrons (Ecuador), C. pseudoangustior (widely distributed across Amazonia), C. satyrus (Brazil), C. unicornus (Brazil) and C. zucca (Ecuador). Lectotypes are here designated for the following species: Camptocerus auricomus Blandford, Camptocerus squammiger Chapuis, Hylesinus gibbus Fabricius, Hylesinus suturalis Fabricius, Hylesinus fasciatus Fabricius. A key, diagnosis, distribution, host records and images were provided for each species

    Approximation in reflexive Banach spaces and applications to the invariant subspace problem

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    We formulate a general approximation problem involving reflexive and smooth Banach spaces, and give its explicit solution. Two applications are presented— the first is to the Bounded Completion Problem involving approximation of Hardy class functions, while the second involves the construction of minimal vec- tors and hyperinvariant subspaces of linear operators, generalizing the Hilbert space technique of Ansari and Enflo

    Approximation in reflexive Banach spaces and applications to the invariant subspace problem

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    We formulate a general approximation problem involving reflexive and smooth Banach spaces, and give its explicit solution. Two applications are presented— the first is to the Bounded Completion Problem involving approximation of Hardy class functions, while the second involves the construction of minimal vec- tors and hyperinvariant subspaces of linear operators, generalizing the Hilbert space technique of Ansari and Enflo

    Mathematical and computer modeling of electro-optic systems using a generic modeling approach

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    The conventional approach to modelling electro-optic sensor systems is to develop separate models for individual systems or classes of system, depending on the detector technology employed in the sensor and the application. However, this ignores commonality in design and in components of these systems. A generic approach is presented for modelling a variety of sensor systems operating in the infrared waveband that also allows systems to be modelled with different levels of detail and at different stages of the product lifecycle. The provision of different model types (parametric and image-flow descriptions) within the generic framework can allow valuable insights to be gained

    A Possible Formation Scenario for Dwarf Spheroidal Galaxies - II: A Parameter Study

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    Dwarf spheroidal (dSph) galaxies are considered the basic building blocks of the galaxy formation process in the LCDM (Lambda Cold Dark Matter) hierarchical cosmological model. These galaxies are believed to be the most dark matter (DM) dominated systems known, have the lowest stellar content, and are poor in gas. Many theories attempt to explain the formation of dSph galaxies resorting to the fact that these galaxies are mainly found orbiting large galaxies or invoking other mechanisms of interactions. Here we show the full set of simulation as an extension of our fiducial model, where we study the formation of classical dSph galaxies in isolation by dissolving star clusters within the DM halo of the dwarf galaxy. In our parameter survey we adopt cored and cusped DM halo profiles and consider different numbers of dissolving star clusters. We investigate the dependency of observable quantities with different masses and scale-lengths of the DM halo and different star formation efficiencies (SFE). We find that our proposed scenario explains many features of the classical dSph galaxies of the Milky Way, like their morphology and their dynamics. We see trends how the surface brightness and the scale-length of the luminous component vary with the parameters of our simulations. We also identify how irregularities in their shape, i.e. clumpiness and ellipticity vary in our simulations. In velocity space, we identify the parameters leading to flat velocity dispersions curves. We recognize kinematically cold substructures in velocity space, named fossil remnants and stemming from our unique initial conditions, which alter the expected results. These streaming motions are considered as a key feature for future observation with high resolution to validate our scenario.Comment: 23 pages, 9 figures, 4 Tables, accepted for publication in MNRA
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