2,697 research outputs found
Chain of Thought Prompt Tuning in Vision Language Models
Language-Image Pre-training has demonstrated promising results on zero-shot
and few-shot downstream tasks by prompting visual models with natural language
prompts. However, most recent studies only use a single prompt for tuning,
neglecting the inherent step-to-step cognitive reasoning process that humans
conduct in complex task settings, for example, when processing images from
unfamiliar domains. Chain of Thought is a simple and effective approximation to
human reasoning process and has been proven useful for natural language
processing (NLP) tasks. Based on this cognitive intuition, we believe that
conducting effective reasoning is also an important problem in visual tasks,
and a chain of thought could be a solution to this problem. In this work, we
propose a novel chain of thought prompt tuning for vision-language modeling.
Extensive experiments show that our method not only generalizes better in image
classification tasks, has greater transferability beyond a single dataset, and
has stronger domain generalization performance, but also performs much better
in imagetext retrieval and visual question answering, which require more
reasoning capabilities. We are the first to successfully adapt chain-of-thought
prompting that combines visual and textual embeddings. We will release our
code
Magnetic connection and current distribution in black hole accretion discs
We discuss one of the possible origins of large-scale magnetic fields based
on a continuous distribution of toroidal electric current flowing in the inner
region of the disc around a Kerr black hole (BH) in the framework of general
relativity. It turns out that four types of configuration of the magnetic
connection (MC) are generated, i.e., MC of the BH with the remote astrophysical
load (MCHL), MC of the BH with the disc (MCHD), MC of the plunging region with
the disc (MCPD) and MC of the inner and outer disc regions (MCDD). It turns out
that the Blandford-Znajek (BZ) process can be regarded as one type of MC, i.e.,
MCHL. In addition, we propose a scenario for fitting the quasi-periodic
oscillations in BH binaries based on MCDD associated with the magnetic
reconnection.Comment: 5 pages, 4 figures, 2 tables. Accepted by MNRAS, 05/05/200
Probing the Circumgalactic Medium at High-Redshift Using Composite BOSS Spectra of Strong Lyman-alpha Forest Absorbers
We present composite spectra constructed from a sample of 242,150 Lyman-alpha
(Lya) forest absorbers at redshifts 2.4<z<3.1 identified in quasar spectra from
the Baryon Oscillation Spectroscopic Survey (BOSS) as part of Data Release 9 of
the Sloan Digital Sky Survey III. We select forest absorbers by their flux in
bins 138 km/s wide (approximately the size of the BOSS resolution element). We
split these absorbers into five samples spanning the range of flux -0.05 <
F<0.45. Tests on a smaller sample of high-resolution spectra show that our
three strongest absorption bins would probe circumgalactic regions (projected
separation < 300 proper kpc and |Delta v| < 300km/s) in about 60% of cases for
very high signal-to-noise ratio. Within this subset, weakening Lya absorption
is associated with decreasing purity of circumgalactic selection once BOSS
noise is included. Our weaker two Lya absorption samples are dominated by the
intergalactic medium.
We present composite spectra of these samples and a catalogue of measured
absorption features from HI and 13 metal ionization species, all of which we
make available to the community. We compare measurements of seven Lyman series
transitions in our composite spectra to single line models and obtain further
constraints from their associated excess Lyman limit opacity. This analysis
provides results consistent with column densities over the range 14.4 <~ Log
(N_HI) <~ 16.45. We compare our measurements of metal absorption to a variety
of simple single-line, single-phase models for a preliminary interpretation.
Our results imply clumping on scales down to ~30 pc and near-solar
metallicities in the circumgalactic samples, while high-ionization metal
absorption consistent with typical IGM densities and metallicities is visible
in all samples.Comment: 23 pages, 15 figures, 5 tables, link to downloadable data included.
Accepted by MNRAS 2014 March 20. New sections 3.4 and 6.1 limiting the
occurrence and impact of Lyman limit system
Quality of reporting of systematic reviews published in “evidence-based” Chinese journals
BACKGROUND: The number of systematic reviews (SRs)/meta-analyses (MAs) has increased dramatically in China over the past decades. However, evaluation of quality of reporting of systematic reviews published has not been undertaken. The objective of this study is to evaluate the quality of reporting of SRs/MAs assessing efficacy and/or harms of clinical interventions published in “evidence-based” Chinese journals. METHODS: Web-based database searches were conducted for the Chinese Journal of Evidence-based Medicine, the Journal of Evidence-Based Medicine, the Chinese Journal of Evidence Based Pediatrics, and the Chinese Journal of Evidence-Based Cardiovascular Medicine. SRs/MAs assessing efficacy and/or harms of clinical interventions were included. The cut-off was December 31st 2011. The PRISMA statement was applied to assess the quality of reporting. Each item was assessed as follows: ‘Yes’ for total compliance, scored ‘1’; ‘partial’ for partial compliance, scored ‘0.5’; and ‘No’ for non-compliance, scored ‘0’. The review was considered to have major flaws if it received a total score of ≤15.0, minor flaws if it received a total score of 15.5 to 21.0, and minimal flaws if it received a total score 21.5 to 27.0. Odds ratios were used for binary variables, and the mean difference was used for continuous variables. Analyses were performed using RevMan 5.0 software. RESULTS: Overall, 487 SRs/MAs were identified and assessed. The included reviews had medium quality with minor flaws based on PRISMA total scores (range: 8.5–26.0; mean: 19.6 ± 3.3). The stratified analysis showed that SRs/MAs with more than 3 authors, from a university, hospital + university cooperation, multiple affiliations (≥2), and funding have significantly higher quality of reporting of SRs/MAs; 58% of the included reviews were considered to have minor flaws (total score of 15.6 to 21.0). Only 9.6% of reviews were considered to have major flaws. Specific areas needing improvement in reporting include the abstract, protocol and registration, and characteristics of the search. CONCLUSIONS: The reporting of SRs published in “evidence-based” Chinese journals is poor and needs to be improved in order for reviews to be useful. SR authors should use the PRISMA checklist to ensure complete and accurate accounts of their SRs
A Generalized Robust Minimization Framework for Low-Rank Matrix Recovery
This paper considers the problem of recovering low-rank matrices which are heavily corrupted by outliers or large errors. To improve the robustness of existing recovery methods, the problem is solved by formulating it as a generalized nonsmooth nonconvex minimization functional via exploiting the Schatten p-norm (0 < p ≤1) and Lq(0 < q ≤1) seminorm. Two numerical algorithms are provided based on the augmented Lagrange multiplier (ALM) and accelerated proximal gradient (APG) methods as well as efficient root-finder strategies. Experimental results demonstrate that the proposed generalized approach is more inclusive and effective compared with state-of-the-art methods, either convex or nonconvex
Correlating the site of tympanic membrane perforation with Hearing loss
This is an Open Access article distributed under the terms of the Creative Commons Attribution Licens
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