720 research outputs found
Open-Vocabulary Semantic Segmentation via Attribute Decomposition-Aggregation
Open-vocabulary semantic segmentation is a challenging task that requires
segmenting novel object categories at inference time. Recent works explore
vision-language pre-training to handle this task, but suffer from unrealistic
assumptions in practical scenarios, i.e., low-quality textual category names.
For example, this paradigm assumes that new textual categories will be
accurately and completely provided, and exist in lexicons during pre-training.
However, exceptions often happen when meet with ambiguity for brief or
incomplete names, new words that are not present in the pre-trained lexicons,
and difficult-to-describe categories for users. To address these issues, this
work proposes a novel decomposition-aggregation framework, inspired by human
cognition in understanding new concepts. Specifically, in the decomposition
stage, we decouple class names into diverse attribute descriptions to enrich
semantic contexts. Two attribute construction strategies are designed: using
large language models for common categories, and involving manually labelling
for human-invented categories. In the aggregation stage, we group diverse
attributes into an integrated global description, to form a discriminative
classifier that distinguishes the target object from others. One hierarchical
aggregation is further designed to achieve multi-level alignment and deep
fusion between vision and text. The final result is obtained by computing the
embedding similarity between aggregated attributes and images. To evaluate the
effectiveness, we annotate three datasets with attribute descriptions, and
conduct extensive experiments and ablation studies. The results show the
superior performance of attribute decomposition-aggregation
[N,N′-Bis(3-methoxy-2-oxidobenzylidene)cyclohexane-1,2-diaminium-κ4 O,O′,O′′,O′′′]tris(nitrato-κ2 O,O′)europium(III) methanol monosolvate
In the title mononuclear salen-type complex, [Eu(NO3)3(C22H26N2O4)]·CH3OH, the EuIII ion is ten-coordinated by three bidentate nitrate counter-ions and one organic salen-type ligand, which acts in a bis-bidentate chelating mode through its phenolate and methoxy O atoms. The protonated imine groups are involved in intramolecular N—H⋯O hydrogen bonds to the phenolate O atomss, emphasizing the zwitterionic nature of the ligand. An O—H⋯O hydrogen bond links the complex and solvent molecules
Fabrication of an integrated high-quality-factor (high-Q) optofluidic sensor by femtosecond laser micromachining
We report on fabrication of a microtoroid resonator of a high-quality factor
(i. e., Q-factor of ~3.24x10^6 measured under the critical coupling condition)
integrated in a microfluidic channel using femtosecond laser three-dimensional
(3D) micromachining. Coupling of light into and out of the microresonator has
been realized with a fiber taper that is reliably assembled with the
microtoroid. The assembly of the fiber to the microtoroid is achieved by
welding the fiber taper onto the sidewall of the microtoroid using CO_2 laser
irradiation. The integrated microresonator maintains a high Q-factor of
3.21x10^5 as measured in air, which should still be sufficient for many sensing
applications. We test the functionality of the integrated optofluidic sensor by
performing bulk refractive index sensing of purified water doped with tiny
amount of salt. It is shown that a detection limit of ~1.2x10^-4 refractive
index unit can be achieved. Our result showcases the capability of integration
of high-Q microresonators with complex microfluidic systems using femtosecond
laser 3D micromachining.Comment: 6 pages, 5 figures. arXiv admin note: text overlap with
arXiv:1402.135
Small Bowel Endoscopy Diagnostic Yield and Reasons of Obscure GI Bleeding in Chinese Patients
Aim. To investigate the diagnostic yield and etiologies of patients with obscure gastrointestinal bleeding (OGIB) using capsule endoscopy (CE) or double-balloon enteroscopy (DBE). Method. We studied the data of 532 consecutive patients with OGIB that were referred to Xinqiao Hospital in Chongqing from December 2005 to January 2012. A lesion that was believed to be the source of the bleeding (ulceration, mass lesion, vascular lesion, visible blood, inflammation, or others) was considered to be a positive finding. We analyzed the diagnostic yield of CE and SBE and the etiologies of OGIB. Result. CE and SBE have similar diagnostic yields, at 71.9% (196/231) and 71.8% (251/304), respectively. The most common etiology was erosions/ulceration (27.1%) followed by mass lesion (19.4%) and angiodysplastic/vascular lesions (13.9%). By stratified analysis, we found that erosions/ulceration (27.1%) was the most common etiology for the 21–40-year age group. Mass lesion was the most common etiology in the 41–60-year age group. However, in the >60 years age group, angiodysplastic/vascular lesions were significantly increased compared with the other groups, even though erosions/ulceration was most common. Conclusion. In this study, we found that CE and SBE have similar diagnostic yields and erosions/ulceration was the most common reason for OGIB, followed by mass lesion and angiodysplasias
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