10,786 research outputs found

    The Presidential Office and the President As Party Leader

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    The Presidential Office and the President As Party Leader

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    Syftet med studien är att undersöka kommunikationsmönster hos fem biologilärare på gymnasiet och deras elevgrupper med fokus på frågor. Frågeställningarna avser att undersöka i vilken omfattning lärare och elever ställer frågor och vilka typer av frågor som ställs. Studien analyserar vilka ramfaktorer lärare och elever anser påverkar kommunikationsmönster i form av frågor. Kvantitativ och kvalitativ data har samlats in genom observationer i klassrum, intervjuer med lärare och enkätundersökning med eleverna. Kvantitativ data har analyserats med hjälp av en statistisk programvara, SIMCA-P+. Resultatet visade att frågor utgör en stor del av den kommunikation som sker i ett klassrum, vid jämförelse av olika lärare och elevgrupper är det stor skillnad i hur många och vilka typer av frågor som ställs. Kommunikationsmönstret styrs främst av vilken lärare eller elevgrupp som observerats, därefter kommer undervisningens utformning. Elevenkäterna visade att i vilken grad eleverna förstår, undervisningens utformning och klassrumsklimatet är viktiga ramfaktorer för kommunikation i form av frågor

    Abusive Trade Practices: An Economic Analysis

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    Constrained invariant mass distributions in cascade decays. The shape of the "mqllm_{qll}-threshold" and similar distributions

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    Considering the cascade decay DcCcbBcbaAD\to c C \to c b B \to c b a A in which D,C,B,AD,C,B,A are massive particles and c,b,ac,b,a are massless particles, we determine for the first time the shape of the distribution of the invariant mass of the three massless particles mabcm_{abc} for the sub-set of decays in which the invariant mass mabm_{ab} of the last two particles in the chain is (optionally) constrained to lie inside an arbitrary interval, mab[mabcut min,mabcut max]m_{ab} \in [ m_{ab}^\text{cut min}, m_{ab}^\text{cut max}]. An example of an experimentally important distribution of this kind is the ``mqllm_{qll} threshold'' -- which is the distribution of the combined invariant mass of the visible standard model particles radiated from the hypothesised decay of a squark to the lightest neutralino via successive two body decay,: \squark \to q \ntlinoTwo \to q l \slepton \to q l l \ntlinoOne , in which the experimenter requires additionally that mllm_{ll} be greater than mllmax/2{m_{ll}^{max}}/\sqrt{2}. The location of the ``foot'' of this distribution is often used to constrain sparticle mass scales. The new results presented here permit the location of this foot to be better understood as the shape of the distribution is derived. The effects of varying the position of the mllm_{ll} cut(s) may now be seen more easily.Comment: 12 pages, 3 figure

    A Review of the Mass Measurement Techniques proposed for the Large Hadron Collider

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    We review the methods which have been proposed for measuring masses of new particles at the Large Hadron Collider paying particular attention to the kinematical techniques suitable for extracting mass information when invisible particles are expected.Comment: 72 pages - in form to be published in JPhys

    Improving estimates of the number of fake leptons and other mis-reconstructed objects in hadron collider events: BoB's your UNCLE. (Previously "The Matrix Method Reloaded")

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    We consider current and alternative approaches to setting limits on new physics signals having backgrounds from misidentified objects; for example jets misidentified as leptons, b-jets or photons. Many ATLAS and CMS analyses have used a heuristic matrix method for estimating the background contribution from such sources. We demonstrate that the matrix method suffers from statistical shortcomings that can adversely affect its ability to set robust limits. A rigorous alternative method is discussed, and is seen to produce fake rate estimates and limits with better qualities, but is found to be too costly to use. Having investigated the nature of the approximations used to derive the matrix method, we propose a third strategy that is seen to marry the speed of the matrix method to the performance and physicality of the more rigorous approach.Comment: v1 :11 pages, 5 figures. v2: title change requested by referee, and other corrections/clarifications found during review. v3: final tweaks suggested during review + move from revtex to jhep styl

    Re-weighing the evidence for a Higgs boson in dileptonic W-boson decays

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    We reconsider observables for discovering and measuring the mass of a Higgs boson via its di-leptonic decays: H --> WW* --> l nu l nu. We define an observable generalizing the transverse mass that takes into account the fact that one of the intermediate W-bosons is likely to be on-shell. We compare this new variable with existing ones and argue that it gives a significant improvement for discovery in the region m_h < 2 m_W.Comment: 3 pages, 2 figures. Changes in v2: (i) implemented a model of detector smearing, (ii) switched LHC simulation from 14 TeV to 7 TeV running, (iii) presenting results for 10 rather than 3 inverse femtobarns, (iv) corrected a typo in Fig 2 legend. Changes in v3: included published erratu

    POPCORN: a Supervisory Control Simulation for Workload and Performance Research

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    A multi-task simulation of a semi-automatic supervisory control system was developed to provide an environment in which training, operator strategy development, failure detection and resolution, levels of automation, and operator workload can be investigated. The goal was to develop a well-defined, but realistically complex, task that would lend itself to model-based analysis. The name of the task (POPCORN) reflects the visual display that depicts different task elements milling around waiting to be released and pop out to be performed. The operator's task was to complete each of 100 task elements that ere represented by different symbols, by selecting a target task and entering the desired a command. The simulated automatic system then completed the selected function automatically. Highly significant differences in performance, strategy, and rated workload were found as a function of all experimental manipulations (except reward/penalty)
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