5,951 research outputs found
GelFlow: Self-supervised Learning of Optical Flow for Vision-Based Tactile Sensor Displacement Measurement
High-resolution multi-modality information acquired by vision-based tactile
sensors can support more dexterous manipulations for robot fingers. Optical
flow is low-level information directly obtained by vision-based tactile
sensors, which can be transformed into other modalities like force, geometry
and depth. Current vision-tactile sensors employ optical flow methods from
OpenCV to estimate the deformation of markers in gels. However, these methods
need to be more precise for accurately measuring the displacement of markers
during large elastic deformation of the gel, as this can significantly impact
the accuracy of downstream tasks. This study proposes a self-supervised optical
flow method based on deep learning to achieve high accuracy in displacement
measurement for vision-based tactile sensors. The proposed method employs a
coarse-to-fine strategy to handle large deformations by constructing a
multi-scale feature pyramid from the input image. To better deal with the
elastic deformation caused by the gel, the Helmholtz velocity decomposition
constraint combined with the elastic deformation constraint are adopted to
address the distortion rate and area change rate, respectively. A local flow
fusion module is designed to smooth the optical flow, taking into account the
prior knowledge of the blurred effect of gel deformation. We trained the
proposed self-supervised network using an open-source dataset and compared it
with traditional and deep learning-based optical flow methods. The results show
that the proposed method achieved the highest displacement measurement
accuracy, thereby demonstrating its potential for enabling more precise
measurement of downstream tasks using vision-based tactile sensors
Propozycja standardu ekologicznej kompensacji dla obszarowych zanieczyszczeń z rolnictwa
Non-point source water pollution mainly comes from farmland chemical fertilizers which has become an obstacle of agricultural sustainability and ecological health. As a public policy tool for assessing global ecological crisis and environmental pollution, ecological compensation is important for regional agricultural sustainability. Ecological compensation that farmers receive from governments is based on their reduction of fertilizer application at optimal ecological and economic levels. In this study we estimated the ecological compensation standards for nitrogen non-point pollution in Yixng city with contingent valuation method and cost-benefit method. Results showed that the range of theoretical values of ecological compensation of nitrogen in Yixing City depended upon its optimal ecological and economic nitrogen application levels. The willingness of farmers to accept the compensation was positively correlated with their farming experience and education. There were about half of farmers willing to accept the compensation. Based on the present study, we found Yixing’s ecological compensation standard for controlling nitrogen non-point pollution was 620.0 yuan/hm2 at the current economic development level.Obszarowe zanieczyszczeń wód z rolnictwa pochodzą ze stosowania nawozów sztucznych, stanowiących przeszkodę na drodze do osiągnięcia rolniczej zrównoważoności i równowagi ekologicznej. W tym kontekście ekologiczna kompensacja, stanowiąca narzędzie polityczne do oceny kryzysu ekologicznego i ogólnego poziomu zanieczyszczenia środowiska, okazuje się także ważna w wymiarze lokalnej zrównoważoności rolniczej. Wysokość świadczeń, które rolniczy dostają od władz, jest uwarunkowana poziomem redukcji stosowania nawozów, którego celem jest osiągnięcie poziomu optymalnego zarówno zer strony ekologicznej, jak i ekonomicznej. W tym artykule, przy pomocy Metoda wyceny warunkowej i metody kosztów i korzyści, ustaliliśmy standardy ekologicznej kompensacji dla miasta Yixng. Otrzymane rezultaty pozwalają na stwierdzenie, że zakres teoretycznych wartości ekologicznej kompensacji dla azotu w Yixing zależy od ustalenia optymalnych ekologicznych i ekonomicznych pozimów stosowania azotu. Zainteresowanie rolników otrzymaniem odszkodowania okazało się być pozytywnie skorelowane z ich doświadczeniem rolniczym i poziomem wykształcenia. Chęć jego otrzymania zgłosiła połowa z nich. Ustaliliśmy ponadto, że standard ekologicznej kompensacji dla Yixing odnoszący się kontrolowania obszarowych zanieczyszczeń związanych z nawozami azotowymi wynosi 620.0 yuan/hm2 , przy założeniu obecnego poziomu rozwoju ekonomicznego
2-(Benzotriazol-1-ylmethylamino)benzoic acid
The title compound, C14H12N4O2, a new N,O,N′-tridentate ligand, is V-shaped with the mean plane through the benzotriazole system [planar to within 0.013 (2) Å] inclined by 67.7 (1)° to the mean plane through the benzene ring. In the molecule there is an intramolecular N—H⋯O hydrogen bond involving the amine H atom and the carbonyl O atom. In the crystal structure, symmtry-related molecules are connected by intermolecular O—H⋯N and C—H⋯O hydrogen bonds and C—H⋯π interactions
Gamma rays and neutrinos from dark matter annihilation in galaxy clusters
The -ray and neutrino emissions from dark matter (DM) annihilation in
galaxy clusters are studied. After about one year operation of Fermi-LAT,
several nearby clusters are reported with stringent upper limits of GeV
-ray emission. We use the Fermi-LAT upper limits of these clusters to
constrain the DM model parameters. We find that the DM model distributed with
substructures predicted in cold DM (CDM) scenario is strongly constrained by
Fermi-LAT -ray data. Especially for the leptonic annihilation scenario
which may account for the excesses discovered by
PAMELA/Fermi-LAT/HESS, the constraint on the minimum mass of substructures is
of the level M, which is much larger than that expected
in CDM picture, but is consistent with a warm DM scenario. We further
investigate the sensitivity of neutrino detections of the clusters by IceCube.
It is found that neutrino detection is much more difficult than -rays.
Only for very heavy DM ( TeV) together with a considerable branching
ratio to line neutrinos the neutrino sensitivity is comparable with that of
-rays.Comment: 21 pages, 8 figures and 1 table; extended discussion about the
uncertainties of concentration and subhalo models, figures replotted for
better read; references updated; accepted for publication by Phys. Rev.
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Anodic electrochemistry of mono- and dinuclear aminophenylferrocene and diphenylaminoferrocene complexes
Two related three-membered series of nonlinear aminophenylferrocene and diphenylaminoferrocene
complexes were prepared and characterized by 1H and 13C NMR spectroscopy. The first series consists of
4-(diphenylamino)phenylferrocene (TPA-Fc, 1a), its dimethoxy-substituted tetraphenylphenylenediamine
derivative (M2TPPD-Fc, 1c), and the triphenylamine-bridged bis(ferrocenyl) complex (Fc-TPA-Fc, 1b). The
second series involves bis(4-methoxyphenyl)aminoferrocene (M2DPA-Fc, 1d), 4-methoxyphenylaminoferrocene
(MPA-Fc) with N-phenyl-appended terminal TPA (1e), and the corresponding bis(MPA-Fc)
complex with bridging TPA (1f). The structure of complex 1d was further confirmed by single crystal X-ray
diffraction. Combined investigations, based on anodic voltammetry, UV-vis-NIR spectroelectrochemistry
and density functional theory (DFT) calculations, were conducted to illustrate the influence of the integration
of multiple redox-active components on the sequential oxidation of these complexes. The first
anodic steps in 1a–1f are localized preferentially on the ferrocenyl units, followed by oxidation of the TPA
or TPPD moieties (absent in 1d). Irreversible oxidation of the ferrocene-appended strong donor DPA/MPA
units in 1d–1f terminates the anodic series. The one-electron oxidation of the triphenylamine-bridged
diferrocenyl (1b) and bis(phenylaminoferrocenyl) (1f) complexes triggers their facile redox disproportionation
to dicationic bis(ferrocenium) product
Operative coordination in one case of Intracranial hematoma removal combined with resection of spleen surgery
Objective: the authors summarized the operative coordination means which operated on the the same patients with Intracranial hematoma removal combined with resection of spleen surgery at the same time. Methods: From the perspectives of preoperotive preparation, hand-washing nurses and visiting nurse respectively, the paper elaborated the placement of sterile towels, personnel reasonable stance, the check and management of sterile items, etc. Results:The surgery was finished smoothly. Conclusion:To assist the surgery is a comprehensive test for nurses’ ability at the operating room. The work responsibility should be clearly arranged, and the principle of intraoperative sterile operation should be strictly followed.目的 总结1例颅内血肿清除术和脾切除术这两种手术在同一患者、同一时间施行时的手术配合方法。方法 分别从术前准备、洗手护士、巡回护士工作等角度进行阐述了无菌巾的铺设、人员的合理站位、无菌物品的清点和管理等。结果 手术配合顺利完成。结论 配合该手术是对手术室护士能力的综合考验,必须做到正确、清楚划分各组的工作区域,遵循术中无菌操作原则
Quasi-Periodic Variations in X-ray Emission and Long-Term Radio Observations: Evidence for a Two-Component Jet in Sw J1644+57
The continued observations of Sw J1644+57 in X-ray and radio bands
accumulated a rich data set to study the relativistic jet launched in this
tidal disruption event. The X-ray light curve of Sw J1644+57 from 5-30 days
presents two kinds of quasi-periodic variations: a 200 second quasi-periodic
oscillation (QPO) and a 2.7-day quasi-periodic variation. The latter has been
interpreted by a precessing jet launched near the Bardeen-Petterson radius of a
warped disk. Here we suggest that the 200s QPO could be associated with
a second, narrower jet sweeping the observer line-of-sight periodically, which
is launched from a spinning black hole in the misaligned direction with respect
to the black hole's angular momentum. In addition, we show that this
two-component jet model can interpret the radio light curve of the event,
especially the re-brightening feature starting days after the
trigger. From the data we infer that inner jet may have a Lorentz factor of
and a kinetic energy of , while the outer jet may have a Lorentz factor of
and a kinetic energy of .Comment: 11 pages, 7 figures, accepted for publication in Ap
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