10,487 research outputs found
The Presidential Office and the President As Party Leader
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
Constrained invariant mass distributions in cascade decays. The shape of the "-threshold" and similar distributions
Considering the cascade decay in which
are massive particles and are massless particles, we
determine for the first time the shape of the distribution of the invariant
mass of the three massless particles for the sub-set of decays in
which the invariant mass of the last two particles in the chain is
(optionally) constrained to lie inside an arbitrary interval, . An example of an experimentally
important distribution of this kind is the `` 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 be greater than . 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 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
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")
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
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
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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