7,118 research outputs found
Characterization of low thermal conductivity PAN-based carbon fibers
The microstructure and surface chemistry of eight low thermal conductivity (LTC) PAN-based carbon fibers were determined and compared with PAN-based fibers heat treated to higher temperatures. Based on wide-angle x ray diffraction, the LTC PAN fibers all appear to have a similar turbostratic structure with large 002 d-spacings, small crystallite sizes, and moderate preferred orientation. Limited small-angle x ray scattering (SAXS) results indicate that, with the exception of LTC fibers made by BASF, the LTC fibers do not have well developed pores. Transmission electron microscopy shows that the texture of the two LTC PAN-based fibers studied (Amoco T350/23X and /25X) consists of multiple sets of parallel, wavy, bent layers that interweave with each other forming a complex three dimensional network oriented randomly around the fiber axis. X ray photoelectron spectroscopy (XPS) analysis finds correlations between heat treated temperatures and the surface composition chemistry of the carbon fiber samples
Cultural dimensions of arts entrepreneurship : lessons for Vietnam from Australia
This paper provides an overview of entrepreneurial activities in three non-profit performing arts organisations in Australia and lists implications for Vietnam. The relationship between limited funding, pressure to attract audiences and the need to act entrepreneurially to diversify funding sources characterises both countries. Case studies from Australia were used to analyse how leaders in arts organisations balance the interests of the various funding sources and market opportunities to service their revenue requirements. Our research strengthens the need to study how Vietnamese artists face challenges of financial viability, audience development, and balance between commercialization and artistic creativity. We conclude that entrepreneurship is seen as an important concept for understanding the development of arts organisations in Australia and Vietnam.<br /
COCO-Counterfactuals: Automatically Constructed Counterfactual Examples for Image-Text Pairs
Counterfactual examples have proven to be valuable in the field of natural
language processing (NLP) for both evaluating and improving the robustness of
language models to spurious correlations in datasets. Despite their
demonstrated utility for NLP, multimodal counterfactual examples have been
relatively unexplored due to the difficulty of creating paired image-text data
with minimal counterfactual changes. To address this challenge, we introduce a
scalable framework for automatic generation of counterfactual examples using
text-to-image diffusion models. We use our framework to create
COCO-Counterfactuals, a multimodal counterfactual dataset of paired image and
text captions based on the MS-COCO dataset. We validate the quality of
COCO-Counterfactuals through human evaluations and show that existing
multimodal models are challenged by our counterfactual image-text pairs.
Additionally, we demonstrate the usefulness of COCO-Counterfactuals for
improving out-of-domain generalization of multimodal vision-language models via
training data augmentation.Comment: Accepted to NeurIPS 2023 Datasets and Benchmarks Trac
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Obesity and prostate cancer-specific mortality after radical prostatectomy: results from the Shared Equal Access Regional Cancer Hospital (SEARCH) database.
BackgroundAt the population level, obesity is associated with prostate cancer (PC) mortality. However, few studies analyzed the associations between obesity and long-term PC-specific outcomes after initial treatment.MethodsWe conducted a retrospective analysis of 4268 radical prostatectomy patients within the Shared Equal Access Regional Cancer Hospital (SEARCH) database. Cox models accounting for known risk factors were used to examine the associations between body mass index (BMI) and PC-specific mortality (PCSM; primary outcome). Secondary outcomes included biochemical recurrence (BCR) and castration-resistant PC (CRPC). BMI was used as a continuous and categorical variable (normal <25 kg/m2, overweight 25-29.9 kg/m2 and obese ⩾30 kg/m2). Median follow-up among all men who were alive at last follow-up was 6.8 years (interquartile range=3.5-11.0). During this time, 1384 men developed BCR, 117 developed CRPC and 84 died from PC. Hazard ratios were analyzed using competing-risks regression analysis accounting for non-PC death as a competing risk.ResultsOn crude analysis, higher BMI was not associated with risk of PCSM (P=0.112), BCR (0.259) and CRPC (P=0.277). However, when BMI was categorized, overweight (hazard ratio (HR) 1.99, P=0.034) and obesity (HR 1.97, P=0.048) were significantly associated with PCSM. Obesity and overweight were not associated with BCR or CRPC (all P⩾0.189). On multivariable analysis adjusting for both clinical and pathological features, results were little changed in that obesity (HR=2.05, P=0.039) and overweight (HR=1.88, P=0.061) were associated with higher risk of PCSM, but not with BCR or CRPC (all P⩾0.114) with the exception that the association for overweight was no longer statistical significant.ConclusionsOverweight and obesity were associated with increased risk of PCSM after radical prostatectomy. If validated in larger studies with longer follow-up, obesity may be established as a potentially modifiable risk factor for PCSM
The Marangoni flow of soluble amphiphiles
Surfactant distribution heterogeneities at a fluid/fluid interface trigger
the Marangoni effect, i.e. a bulk flow due to a surface tension gradient. The
influence of surfactant solubility in the bulk on these flows remains
incompletely characterized. Here we study Marangoni flows sustained by
injection of hydrosoluble surfactants at the air/water interface. We show that
the flow extent increases with a decrease of the critical micelle
concentration, i.e. the concentration at which these surfactants self-assemble
in water. We document the universality of the surface velocity field and
predict scaling laws based on hydrodynamics and surfactant physicochemistry
that capture the flow features.Comment: 5 pages, 4 figures, submitte
Semi-Structured Chain-of-Thought: Integrating Multiple Sources of Knowledge for Improved Language Model Reasoning
An important open question pertaining to the use of large language models for
knowledge-intensive tasks is how to effectively integrate knowledge from three
sources: the model's parametric memory, external structured knowledge, and
external unstructured knowledge. Most existing prompting methods either rely
solely on one or two of these sources, or require repeatedly invoking large
language models to generate similar or identical content. In this work, we
overcome these limitations by introducing a novel semi-structured prompting
approach that seamlessly integrates the model's parametric memory with
unstructured knowledge from text documents and structured knowledge from
knowledge graphs. Experimental results on open-domain multi-hop question
answering datasets demonstrate that our prompting method significantly
surpasses existing techniques, even exceeding those which require fine-tuning
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