841 research outputs found

    Marinari-Parisi and Supersymmetric Collective Field Theory

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    A field theoretic formulation of the Marinari-Parisi supersymmetric matrix model is established and shown to be equivalent to a recently proposed supersymmetrization of the bosonic collective string field theory. It also corresponds to a continuum description of super-Calogero models. The perturbation theory of the model is developed and, in this approach, an infinite sequence of vertices is generated. A class of potentials is identified for which the spectrum is that of a massless boson and Majorana fermion. For the harmonic oscillator case, the cubic vertices are obtained in an oscillator basis. For a rather general class of potentials it is argued that one cannot generate from Marinari-Parisi models a continuum limit similar to that of the d=1 bosonic string.Comment: 45 page

    Unpacking qualitative methodology to explore experiences of mothers with children with autism spectrum disorder in the UAE: a thematic analysis inquiry

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    The current study provides a detailed description of the qualitative research design and methodology, used while exploring challenges and support structures experienced by expat mothers of children with Autism Spectrum Disorder (ASD) in the United Arab Emirates. In-depth, face-to-face, semi-structured interviews were administered with 17 mothers recruited using purposive and snowball sampling. Recurrent and relevant themes were generated using thematic analysis. Given there is a greater need for highlighting methodological rigor in qualitative research, we discuss steps such as a) using field knowledge to create an interview protocol, b) administering collaborative qualitative research, c) having strong eligibility criteria for participants, d) incorporating perspectives of multiple coders in the analytical process, e) being reflective and aware of one’s potential biases, f) enhancing interview protocol based on pilot interviews, g) and focusing on the quality of perspectives or information power instead of quantity of perspectives. Interpretation of findings and recommendation of evidence-informed guidelines incorporates strengths and limitations of the qualitative methodology utilized in the study

    Kan die kernwapenwedloop deur kern-wapenbeheer beëindig word?

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    The slogans of the "walkers for peace " in the Uniled Slates of America anti in Western Europe (and also in South Africa) against the proliferation of nuclear weapons and nuclear technology as well as the growing probability of a nuclear war in the light of president Reagan's rearmament plan, arc born of the numerous failures of nuclear disarmament and arms control. The ever- increasing danger that goes along with nuclear proliferation in the sense of weapon production and the handling of radioactive waste urges us to look more seriously than ever at nuclear technology. The article deals with some of the efforts to control the proliferation process as well as efforts to limit or reduce nuclear arms. Some essential  factors that negatively influence the discussions are pointed out and finally it is concluded that because of the sin-induced brokenness of man’s heart, control over nuclear arms proliferation has just partial success. The abolition of weapon production and total disarm­ ament are ideals that will, in this era that precedes the second coming of Christ, not be fulfilled. Thus, the nuclear arms race will inevitably continue

    The postmodern consumer: implications of changing customer expectations for organisation development in service organisations.

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    Postmodern society is predominantly viewed as a consumption- oriented society that developed as a reaction to the more traditional, modern society. The observed divide between modern and postmodern societies suggests different consumption patterns and consumer profiles which could have significant implications for service organisations. The discussion contrasted the modern and postmodern eras and societies, and isolated the main characteristics and service expectations of the postmodern consumer. The implications for organisation development (OD) in service organisations, notably in terms of the changes that are required, are highlighted

    Exploring challenges and support structures of mothers with children with Autism Spectrum Disorder in the United Arab Emirates

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    Mothers with children with ASD, often being primary caregivers, experience high levels of parenting stress and hold essential information about their children's wellbeing. There is however lack of information about their experiences in the UAE. The study aims to explore challenges and support structures of mothers with children with ASD in the UAE. 17 expat mothers (Age = 33-58 years) with a child with ASD were interviewed about their experiences with diagnoses, therapeutic interventions, support networks, and the pandemic. Thematic analysis showed that initially most mothers struggled with accessing information to seek correct diagnoses, admission in mainstream international schools with typically developing children, and finding appropriate therapeutic services. Several mothers narrated experiences of not receiving optimum support from their partners, feeling rejected from extended family members, and facing hardships during the pandemic. Majority however appeared to be extremely satisfied with support groups where they felt heard and exchanged experience-based information crucial for children's wellbeing. Findings highlight the need for the government to facilitate centralized channels of information for expat parents with children with developmental disabilities, formalizing more support groups for mothers in the UAE, and increasing knowledge about autism to decrease biases. [Abstract copyright: Copyright © 2021 Elsevier Ltd. All rights reserved.

    A lambda calculus for quantum computation with classical control

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    The objective of this paper is to develop a functional programming language for quantum computers. We develop a lambda calculus for the classical control model, following the first author's work on quantum flow-charts. We define a call-by-value operational semantics, and we give a type system using affine intuitionistic linear logic. The main results of this paper are the safety properties of the language and the development of a type inference algorithm.Comment: 15 pages, submitted to TLCA'05. Note: this is basically the work done during the first author master, his thesis can be found on his webpage. Modifications: almost everything reformulated; recursion removed since the way it was stated didn't satisfy lemma 11; type inference algorithm added; example of an implementation of quantum teleportation adde

    The superfield quantisation of a superparticle action with an extended line element

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    A massive superparticle action based on the generalised line element in N = 1 global superspace is quantised canonically. A previous method of quantising this action, based on a Fock space analysis, showed that states existed in three supersymmetric multiplets, each of a different mass. The quantisation procedure presented uses the single first class constraint as an operator condition on a general N = 1 superwavefunction. The constraint produces coupled equations of motion for the component wavefunctions. Transformations of the component wavefunctions are derived that decouple the equations of motion and partition the resulting wavefunctions into three separate supermultiplets. Unlike previous quantisations of superparticle actions in N = 1 global superspace, the spinor wavefunctions satisfy the Dirac equation and the vector wavefunctions satisfy the Proca equation. The off-shell closure of the commutators of the supersymmetry transformations, that include mass parameters, are derived by the introduction of auxiliary wavefunctions. To avoid the ghosts arising in a previous Fock space quantisation an alternative conjugation is used in the definition of the current, based on a Krein space approach

    Scientific collaboration with educators: practical insights from an in‐class noise‐reduction intervention

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    Moving the field of Mind, Brain, and Education forward requires researchers and educators to reframe the boundaries of their own discipline in order to create knowledge that is both scientifically based, and of practical relevance for education. We believe that this could be done by co‐constructing research projects from the start. We present a case study of a noise‐reduction intervention in elementary classrooms, in which teachers and researchers worked together from the onset of study design. We examine the processes behind: (1) selecting research questions and measures, (2) planning interventions, (3) receiving ethical approval and funding, (4) recruiting schools, and (5) collecting data. At each step, our study provides suggestions for future collaborative efforts, keeping in mind broader theoretical and methodological implications. We believe that our concrete examples and suggestions will be useful for beginning and confirmed researchers, as well as teachers aiming to know more about research projects

    A cost effective public transport management system for go!durban

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    The eThekwini Transport Authority (ETA) is implementing an Integrated Public Transport Network (Go!Durban) which is essentially a traditional BRT system. Go!Durban requires a Public Transport Management System (PTMS) in order to monitor the performance and compliance of the BRT operator and provide real time information on the BRT system. In 2014, the ETA advertised a tender for an Advanced PTMS. The lowest tender to specification was priced at around R350 million. This was deemed too expensive, and the tender was not awarded. Subsequent to this, in 2018 the ETA commenced discussions with Netstar, the current eThekwini fleet management contractor, to extend their fleet management system to include compliance monitoring, thus meeting the core functionality of a PTMS. The Go!Durban team developed a minimum User Requirements Specification (URS), based on the original ETA APTMS specification, which Netstar then used to map their proposal and cost estimate to develop the system. The system is being developed in two phases with a Proof of Concept or Pilot phase, building on their existing system functionality, followed by a Phase 2 to address the gaps in the APTMS minimum URS – essentially functionality that required further development. Based on the Netstar fleet management system, the ETA has thus developed a cost-effective PTMS to support the operations of the Go! Durban Integrated Public Transport Network (IPTN). This PTMS Lite system provides the essential functionality of the traditional PTMS at a fraction of the cost. The ETA PTM Lite System is a tool to manage bus movements against a static timetable on the Go!Durban corridors and provide appropriate reporting and bus communication for the Transport Operator. In order to drive down operational costs (and therefore subsidies) ITS practitioners have a significant role to play in looking for cost effective solutions. The Netstar system presented here offers significant cost savings for capital and operating budgets. It offers an application centric solution for passenger information and provides all the essential functionality of a traditional APTMS at around a tenth of the cost. This should assist planners in their quest for a more financially sustainable public transport system.Papers presented virtually at the 39th International Southern African Transport Conference on 05 -07 July 202
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