3,070 research outputs found
Shape sensitivity analysis of flutter response of a laminated wing
A method is presented for calculating the shape sensitivity of a wing aeroelastic response with respect to changes in geometric shape. Yates' modified strip method is used in conjunction with Giles' equivalent plate analysis to predict the flutter speed, frequency, and reduced frequency of the wing. Three methods are used to calculate the sensitivity of the eigenvalue. The first method is purely a finite difference calculation of the eigenvalue derivative directly from the solution of the flutter problem corresponding to the two different values of the shape parameters. The second method uses an analytic expression for the eigenvalue sensitivities of a general complex matrix, where the derivatives of the aerodynamic, mass, and stiffness matrices are computed using a finite difference approximation. The third method also uses an analytic expression for the eigenvalue sensitivities, but the aerodynamic matrix is computed analytically. All three methods are found to be in good agreement with each other. The sensitivities of the eigenvalues were used to predict the flutter speed, frequency, and reduced frequency. These approximations were found to be in good agreement with those obtained using a complete reanalysis
Emergent inabilities? Inverse scaling over the course of pretraining
Does inverse scaling only occur as a function of model size, or can it also
occur over the course of training? We carry out an exploratory study
investigating whether the performance of language models on specific tasks can
decrease (while general performance remains high) during training on the
language modeling task. We find 8 tasks on which Pythia 12B (Biderman et al.,
2023) shows decreased performance over the course of training. Five of these
tasks (TruthfulQA-MC1, TruthfulQA-MC2, Hindsight Neglect, Memo Trap, and
Pattern Match Suppression) additionally show a consistent relationship whereby
larger language models show a greater decrease in performance the more they are
trained, despite showing standard (positive) scaling overall. This highlights
the importance of testing performance at all relevant benchmarks any time
models are trained on additional data, even if their overall performance
improvesComment: Accepted to Findings of EMNLP 202
Do language models make human-like predictions about the coreferents of Italian anaphoric zero pronouns?
Some languages allow arguments to be omitted in certain contexts. Yet human
language comprehenders reliably infer the intended referents of these zero
pronouns, in part because they construct expectations about which referents are
more likely. We ask whether Neural Language Models also extract the same
expectations. We test whether 12 contemporary language models display
expectations that reflect human behavior when exposed to sentences with zero
pronouns from five behavioral experiments conducted in Italian by Carminati
(2005). We find that three models - XGLM 2.9B, 4.5B, and 7.5B - capture the
human behavior from all the experiments, with others successfully modeling some
of the results. This result suggests that human expectations about coreference
can be derived from exposure to language, and also indicates features of
language models that allow them to better reflect human behavior.Comment: Accepted at COLING 202
Does clinical management improve outcomes following self-Harm? Results from the multicentre study of self-harm in England
Background
Evidence to guide clinical management of self-harm is sparse, trials have recruited selected samples, and psychological treatments that are suggested in guidelines may not be available in routine practice.
Aims
To examine how the management that patients receive in hospital relates to subsequent outcome.
Methods
We identified episodes of self-harm presenting to three UK centres (Derby, Manchester, Oxford) over a 10 year period (2000 to 2009). We used established data collection systems to investigate the relationship between four aspects of management (psychosocial assessment, medical admission, psychiatric admission, referral for specialist mental health follow up) and repetition of self-harm within 12 months, adjusted for differences in baseline demographic and clinical characteristics.
Results
35,938 individuals presented with self-harm during the study period. In two of the three centres, receiving a psychosocial assessment was associated with a 40% lower risk of repetition, Hazard Ratios (95% CIs): Centre A 0.99 (0.90–1.09); Centre B 0.59 (0.48–0.74); Centre C 0.59 (0.52–0.68). There was little indication that the apparent protective effects were mediated through referral and follow up arrangements. The association between psychosocial assessment and a reduced risk of repetition appeared to be least evident in those from the most deprived areas.
Conclusion
These findings add to the growing body of evidence that thorough assessment is central to the management of self-harm, but further work is needed to elucidate the possible mechanisms and explore the effects in different clinical subgroups
Can Peanuts Fall in Love with Distributional Semantics?
The context in which a sentence appears can drastically alter our
expectations about upcoming words - for example, following a short story
involving an anthropomorphic peanut, experimental participants are more likely
to expect the sentence 'the peanut was in love' than 'the peanut was salted',
as indexed by N400 amplitude (Nieuwland & van Berkum, 2006). This rapid and
dynamic updating of comprehenders' expectations about the kind of events that a
peanut may take part in based on context has been explained using the construct
of Situation Models - updated mental representations of key elements of an
event under discussion, in this case, the peanut protagonist. However, recent
work showing that N400 amplitude can be predicted based on distributional
information alone raises the question whether situation models are in fact
necessary for the kinds of contextual effects observed in previous work. To
investigate this question, we attempt to model the results of Nieuwland and van
Berkum (2006) using six computational language models and three sets of word
vectors, none of which have explicit situation models or semantic grounding. We
find that the effect found by Nieuwland and van Berkum (2006) can be fully
modeled by two language models and two sets of word vectors, with others
showing a reduced effect. Thus, at least some processing effects normally
explained through situation models may not in fact require explicit situation
models
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