172 research outputs found
Few-Cost Salient Object Detection with Adversarial-Paced Learning
Detecting and segmenting salient objects from given image scenes has received
great attention in recent years. A fundamental challenge in training the
existing deep saliency detection models is the requirement of large amounts of
annotated data. While gathering large quantities of training data becomes cheap
and easy, annotating the data is an expensive process in terms of time, labor
and human expertise. To address this problem, this paper proposes to learn the
effective salient object detection model based on the manual annotation on a
few training images only, thus dramatically alleviating human labor in training
models. To this end, we name this task as the few-cost salient object detection
and propose an adversarial-paced learning (APL)-based framework to facilitate
the few-cost learning scenario. Essentially, APL is derived from the self-paced
learning (SPL) regime but it infers the robust learning pace through the
data-driven adversarial learning mechanism rather than the heuristic design of
the learning regularizer. Comprehensive experiments on four widely-used
benchmark datasets demonstrate that the proposed method can effectively
approach to the existing supervised deep salient object detection models with
only 1k human-annotated training images. The project page is available at
https://github.com/hb-stone/FC-SOD
Shape model and rotation acceleration of (1685) Toro and (85989) 1999 JD6 from optical observations
The Yarkovsky-O'Keefe-Radzievskii-Paddack (YORP) effect is a net torque
caused by solar radiation directly reflected and thermally re-emitted from the
surface of small asteroids and is considered to be crucial in their dynamical
evolution. By long-term photometric observations of selected near-Earth
asteroids, it's hoped to enlarge asteroid samples with a detected YORP effect
to facilitate the development of a theoretical framework. Archived light-curve
data are collected and photometric observations are made for (1685) Toro and
(85989) 1999 JD6, which enables measurement of their YORP effect by inverting
the light curve to fit observations from a convex shape model. For (1685) Toro,
a YORP acceleration is updated, which is consistent with previous YORP
detection based on different light-curve data; for (85989) 1999 JD6, it is
determined that the sidereal period is h, the rotation
pole direction locates is at , the acceleration is detected to be and in addition
to obtaining an excellent agreement between the observations and model. YORP
should produce both spin-up and spin-down cases. However, including (85989)
1999 JD6, the values of eleven near-Earth asteroids are
positive totally, which suggests that there is either a bias in the sample of
YORP detections or a real feature needs to be explained.Comment: 21 pages, 10 figure
Rapid transform optimisation strategy for decoherence-protected quantum register in diamond
Decoherence-protected spins associated with nitrogen-vacancy color centers in
diamond possess remarkable long coherence time, which make them one of the most
promising and robust quantum registers. The current demand is to explore
practical rapid control strategies for preparing and manipulating the such
register. Our work provides all-microwave control strategies optimized using
multiple optimization methods to significantly reduce the processing time by
with a set of smooth near-zero-endpoints control fields that are shown
to be experimentally realizable. Furthermore, we optimize and analyze the
robustness of these strategies under frequency and amplitude imperfections of
the control fields, during which process we use only samples to give a
fair estimation of the robustness map with pixels. Overall, we provide a
ready-to-implement recipe to facilitate high-performance information processing
via decoherence-protected quantum register for future quantum technology
applications.Comment: 8 pages, 5 figure
Comparative Study on Volatile Flavor of Chinese Acid-curd Cheese Using Sensory Evaluation, Gas Chromatography-Ion Mobility Spectrometry and Gas Chromatography-Mass Spectrometry
The difference in the volatile flavors of five different Chinese acid-curd cheeses including milk fan, milk cake, Qula (yak milk cheese), Hurood cheese and milk knot was analyzed by sensory evaluation, gas chromatography-ion mobility spectrometry (GC-IMS) and gas chromatography-mass spectrometry (GC-MS). The results of sensory evaluation showed that the five cheeses had a significant difference in flavor. Among them, dairy fan, with strong milky, fruity and bread-like aromas, had the best overall aroma performance and the highest preference score. The combination of GC-IMS and GC-MS expanded the detection range of volatile flavor compounds, and could more comprehensively reflect the volatile compounds in different Chinese acid-curd cheeses. The sensory evaluation results were verified by GC-IMS analysis. All five samples had their own characteristic peak areas, and the characteristic peak areas of dairy fan and Qula were significantly larger than those of the other samples. GC-MS analysis showed that the proportion of acids in dairy fan, Hurood cheese and Qula was the highest, the proportion of esters in milk cake was the highest, and the proportion of alcohols in milk knot was the highest. The calculation of odor activity value (OAV) combined with the results of principal component analysis (PCA) showed that ethanol, ethyl butyrate, ethyl caproate, 2-heptanone and δ-caprylactone were the major contributors to the flavor of dairy fan. Phenethyl formate, phenethyl acetate, caprylic acid, lauric acid and n-decanoic acid were the major contributors to the flavor of Qula. Dodecyl aldehyde was identified as the characteristic flavor compound of dairy cake. Partial least squares analysis (PLSA) revealed the correlation between aroma properties and volatile flavor compounds. Dairy fan has the potential to be developed and promoted in China because of its excellent flavor and consumer preference
Even Visually Intact Cell Walls in Waterlogged Archaeological Wood Are Chemically Deteriorated and Mechanically Fragile: A Case of a 170 Year-Old Shipwreck
Structural and chemical deterioration and its impact on cell wall mechanics were investigated for visually intact cell walls (VICWs) in waterlogged archaeological wood (WAW). Cell wall mechanical properties were examined by nanoindentation without prior embedding. WAW showed more than 25% decrease of both hardness and elastic modulus. Changes of cell wall composition, cellulose crystallite structure and porosity were investigated by ATR-FTIR imaging, Raman imaging, wet chemistry, 13C-solid state NMR, pyrolysis-GC/MS, wide angle X-ray scattering, and N2 nitrogen adsorption. VICWs in WAW possessed a cleavage of carboxyl in side chains of xylan, a serious loss of polysaccharides, and a partial breakage of β-O-4 interlinks in lignin. This was accompanied by a higher amount of mesopores in cell walls. Even VICWs in WAW were severely deteriorated at the nanoscale with impact on mechanics, which has strong implications for the conservation of archaeological shipwrecks
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