4,710 research outputs found

    Measuring Employee Turnover in Australian Pig Production

    Get PDF
    Limited availability of competent and motivated staff has been repeatedly cited as one of the major constraints on pig production in Australia. Whilst a considerable effort is put into training staff (Western Australia boasts the most advanced training facility in South-East Asia), practically nothing is known about the rates of employee turnover. Based on a postal survey and case studies of high and low turnover piggeries, this paper provides the first objective measures of staff turnover in the pig industry and explores possible explanatory factors. Measurement of turnover can provide managers with a benchmark to assess their own performance. This study also revealed shortcomings in the standard Separation Method used by the Australian Bureau of Statistics when it is applied to relatively small businesses. Alternative measures were calculated and are discussed.Farm Management,

    On algebraic structures in supersymmetric principal chiral model

    Full text link
    Using the Poisson current algebra of the supersymmetric principal chiral model, we develop the algebraic canonical structure of the model by evaluating the fundamental Poisson bracket of the Lax matrices that fits into the rs matrix formalism of non-ultralocal integrable models. The fundamental Poisson bracket has been used to compute the Poisson bracket algebra of the monodromy matrix that gives the conserved quantities in involution

    New approaches to Spanish anarchism

    Get PDF
    © 2016 Intellect Ltd Introduction. This article introduces the themes of this special edition, presenting the case that the history of Spanish anarchism needs to be situated within a broader, international history of the left. This view helps to disrupt the image of anarchism as 'exceptional', without losing sight of its specific manifestation in Spain. It proceeds to outline the five articles that make up the remainder of the edition

    Auxiliary Fields for Super Yang-Mills from Division Algebras

    Get PDF
    Division algebras are used to explain the existence and symmetries of various sets of auxiliary fields for super Yang-Mills in dimensions d=3,4,6,10d=3,4,6,10. (Contribution to G\"ursey Memorial Conference I: Strings and Symmetries)Comment: 7 pages, plain TeX, CERN-TH.7470/9

    A homomorphism theorem and a Trotter product formula for quantum stochastic flows with unbounded coefficients

    Full text link
    We give a new method for proving the homomorphic property of a quantum stochastic ow satisfying a quantum stochastic differential equation with unbounded coefficients, under some further hypotheses. As an application, we prove a Trotter product formula for quantum stochastic ows and obtain quantum stochastic dilations of a class of quantum dynamical semigroups generalizing results of [5

    Density profiles of a colloidal liquid at a wall under shear flow

    Get PDF
    Using a dynamical density functional theory we analyze the density profile of a colloidal liquid near a wall under shear flow. Due to the symmetries of the system considered, the naive application of dynamical density functional theory does not lead to a shear induced modification of the equilibrium density profile, which would be expected on physical grounds. By introducing a physically motivated dynamic mean field correction we incorporate the missing shear induced interparticle forces into the theory. We find that the shear flow tends to enhance the oscillations in the density profile of hard-spheres at a hard-wall and, at sufficiently high shear rates, induces a nonequilibrium transition to a steady state characterized by planes of particles parallel to the wall. Under gravity, we find that the center-of-mass of the density distribution increases with shear rate, i.e., shear increases the potential energy of the particles

    Real Forms of Non-abelian Toda Theories and their W-algebras

    Get PDF
    We consider real forms of Lie algebras and embeddings of sl(2) which are consistent with the construction of integrable models via Hamiltonian reduction. In other words: we examine possible non-standard reality conditions for non-abelian Toda theories. We point out in particular that the usual restriction to the maximally non-compact form of the algebra is unnecessary, and we show how relaxing this condition can lead to new real forms of the resulting W-algebras. Previous results for abelian Toda theories are recovered as special cases. The construction can be extended straightforwardly to deal with osp(1|2) embeddings in Lie superalgebras. Two examples are worked out in detail, one based on a bosonic Lie algebra, the other based on a Lie superalgebra leading to an action which realizes the N=4 superconformal algebra.Comment: 11 pages, LaTex; minor errors corrected, extra references adde

    On the Classification of Real Forms of Non-Abelian Toda Theories and W-algebras

    Get PDF
    We consider conformal non-Abelian Toda theories obtained by hamiltonian reduction from Wess-Zumino-Witten models based on general real Lie groups. We study in detail the possible choices of reality conditions which can be imposed on the WZW or Toda fields and prove correspondences with sl(2,R) embeddings into real Lie algebras and with the possible real forms of the associated W-algebras. We devise a a method for finding all real embeddings which can be obtained from a given embedding of sl(2,C) into a complex Lie algebra. We then apply this to give a complete classification of real embeddings which are principal in some simple regular subalgebra of a classical Lie algebra.Comment: 42 pages, LaTeX; Minor corrections to ensure consistent conventions; some references adde

    Conserved charges and supersymmetry in principal chiral and WZW models

    Get PDF
    Conserved and commuting charges are investigated in both bosonic and supersymmetric classical chiral models, with and without Wess-Zumino terms. In the bosonic theories, there are conserved currents based on symmetric invariant tensors of the underlying algebra, and the construction of infinitely many commuting charges, with spins equal to the exponents of the algebra modulo its Coxeter number, can be carried out irrespective of the coefficient of the Wess-Zumino term. In the supersymmetric models, a different pattern of conserved quantities emerges, based on antisymmetric invariant tensors. The current algebra is much more complicated than in the bosonic case, and it is analysed in some detail. Two families of commuting charges can be constructed, each with finitely many members whose spins are exactly the exponents of the algebra (with no repetition modulo the Coxeter number). The conserved quantities in the bosonic and supersymmetric theories are only indirectly related, except for the special case of the WZW model and its supersymmetric extension.Comment: LaTeX; 49 pages; v2: minor changes and additions to text and ref

    Higher-spin conserved currents in supersymmetric sigma models on symmetric spaces

    Get PDF
    Local higher-spin conserved currents are constructed in the supersymmetric sigma models with target manifolds symmetric spaces G/HG/H. One class of currents is based on generators of the de Rham cohomology ring of G/HG/H; a second class of currents are higher-spin generalizations of the (super)energy-momentum tensor. A comprehensive analysis of the invariant tensors required to construct these currents is given from two complimentary points of view, and sets of primitive currents are identified from which all others can be constructed as differential polynomials. The Poisson bracket algebra of the top component charges of the primitive currents is calculated. It is shown that one can choose the primitive currents so that the bosonic charges all Poisson-commute, while the fermionic charges obey an algebra which is a form of higher-spin generalization of supersymmetry. Brief comments are made on some implications for the quantized theories.Comment: 40 pages; LaTe
    corecore