35 research outputs found
Ciriottiite, Cu(Cu,Ag)3Pb19(Sb,As)22(As2)S56, the Cu-analogue of sterryite from the Tavagnasco mining district, Piedmont, Italy
No full textThe new mineral species ciriottiite, ideally Cu(Cu,Ag)3Pb19(Sb,As)22(As2)S56 has been discovered in the Tavagnasco mining district, Piedmont, Italy, as very rare black metallic tubular crystals, up to 150 μm in length, associated with Bi sulfosalts and arsenopyrite. Its Vickers hardness (VHN10) is 203 kg/mm2 (range 190-219). In reflected light, ciriottiite is light grey in color, distinctly anisotropic with brownish to greenish rotation tints. Internal reflections are absent. Reflectance values for the four COM wavelengths (Rmin, Rmax (%) (λ in nm)) are: 33.2, 37.8 (471.1); 31.8, 35.3 (548.3), 31.0, 34.7 (586.6); and 27.9, 32.5 (652.3). Electron microprobe analysis gave (in wt %, average of 5 spot analyses): Cu 2.33 (8), Ag 0.53 (5), Hg 0.98 (6), Tl 0.78 (3), Pb 44.06 (14), As 4.66 (7), Sb 23.90 (10), Bi 1.75 (7), total 99.38 (26). On the basis of 56 S atoms per formula unit, the chemical formula of ciriottiite is Cu3.23(11)Ag0.43(4)Hg0.43(2)Pb18.74(9)Tl0.34(1)Sb17.30(5)As5.48(10)Bi0.74(3)S56. The main diffraction lines, corresponding to multiple hkl indices, are (d in Å (relative visual intensity)): 4.09 (m), 3.91 (m), 3.63 (vs), 3.57 (m), 3.22 (m), 2.80 (mw), 2.07 (s). The crystal structure study revealed ciriottiite to be monoclinic, space group P21/n, with unit-cell parameters a = 8.178 (2), b = 28.223 (6), c = 42.452 (5) Å, β= 93.55 (2)°, V = 9779.5 (5) Å3, Z = 4. The crystal structure was refined to a final R1 = 0.118 for 21304 observed reflections. Ciriottiite is the Cu analogue of sterryite and can be described as an expanded derivative of owyheeite. The name ciriottiite honors Marco Ernesto Ciriotti (b. 1945) for his longstanding contribution to mineral systematics
Tavagnascoite, Bi4O4(SO4)(OH)2, a new oxyhydroxy bismuth sulfate related to klebelsbergite
No full textThe new mineral tavagnascoite, Bi4O4(SO4)(OH)2, was discovered in the Pb-Bi-Zn-As-Fe-Cu ore district of Tavagnasco, Turin, Piedmont, Italy. It occurs as blocky, colourless crystals, up to 40 μm in size, with a silky lustre. In the specimen studied, tavagnascoite is associated with other uncharacterized secondary Bi-minerals originating fromthe alteration of a bismuthinite ± Bi-sulfosalt assemblage. Electronmicroprobe analyses gave (average of three spot analyses, wt.%) Bi2O3 85.32, Sb2O3 0.58, PbO 2.18, SO3 8.46,H2Ocalc 1.77, sum 98.31. On the basis of 10 O apfu, the chemical formula is (Bi3.74Pb0.10Sb0.04)Σ = 3.88O3.68(SO4)1.08(OH)2, with rounding errors. Main calculated diffraction lines are [d in A (relative intensity) hkl] 6.39 (29) 012, 4.95 (19) 111, 4.019 (32) 121, 3.604 (28) 014 and 3.213 (100) 123. Unit-cell parameters are a = 5.831(1), b = 11.925(2), c = 15.123(1) A, V = 1051.6(3) A3, Z = 4, space group Pca21. The crystal structure was solved and refined from single-crystal X-ray diffraction data to R1 = 0.037 on the basis of 1269 observed reflections. It consists of Bi-O polyhedra and SO4 tetrahedra. Bismuth polyhedra are connected each to other to form Bi-O sheets parallel to (001). Successive sheets are linked together by SO4 groups and hydrogen bonds. Tavagnascoite is the Bi-Analogue of klebelsbergite, Sb4O4(SO4)(OH)2, and it is the fifth natural known bismuth sulfate without additional cations. The mineral and its name have been approved by the IMA CNMNC (2014-099)
Some computations on the characteristic variety of a line arrangement
No full textWe find monodromy formulas for line arrangements that are fibered with respect to the projection from one point. We use them to find 0-dimensional translated components in the first characteristic variety of the arrangement [InlineEquation not available: see fulltext.] determined by a regular n-polygon and its diagonals. We also find new 1-dimensional translated components which generalize the well-known case of the B3-deleted arrangement. © 2020, The Author(s)
MPOSE2021: a Dataset for Short-Time Pose-Based Human Action Recognition
No full textThis repository contains the MPOSE2021 Dataset for short-time pose-based Human Action Recognition (HAR). MPOSE2021 is specifically designed to perform short-time Human Action Recognition.
MPOSE2021 is developed as an evolution of the MPOSE Dataset [1-3]. It is made by human pose data detected by OpenPose [4] and Posenet [11] on popular datasets for HAR, i.e. Weizmann [5], i3DPost [6], IXMAS [7], KTH [8], UTKinetic-Action3D (RGB only) [9] and UTD-MHAD (RGB only) [10], alongside original video datasets, i.e. ISLD and ISLD-Additional-Sequences [1]. Since these datasets have heterogenous action labels, each dataset labels are remapped to a common and homogeneous list of actions. Generated sequences have a number of frames between 20 and 30. Sequences are obtained by cutting the so-called Precursor videos (video from the above-mentioned datasets), with non-overlapping sliding windows. Frames where OpenPose/PoseNet cannot detect any subject are automatically discarded. Resulting samples contain one subject at the time, performing a fraction of a single action. Overall, MPOSE2021 contains 15429 samples, divided into 20 actions, performed by 100 subjects.
More information about the dataset can be found in the MPOSE2021 repository, also providing a user-friendly Python package to import and use the dataset by just running the command
pip install mpose
Data Structure
The repository contains 3 datasets for each pose extractor (namely 1, 2 and 3) which consist of the same data divided in different train/test splits. Each dataset contains X and y numpy arrays for both training and testing. X has the following shape:
(B, T, K, C)
where
B is the batch number;
T (= 30) is the duration of the sequences in frames (zero-padded in the case of shorter sequences);
K (= 17 for PoseNet and 25 for OpenPose) is the number of pose keypoints;
C (= 3) is the number of channels, comprehending 2D keypoint coordinates (x,y) in the original video reference frame and the keypoint confidence (p <= 1)
The .txt files specifying the metadata associated with the split samples are also included.
References
MPOSE2021 is part of a paper published by the Pattern Recognition Journal (Elsevier), and is intended for scientific research purposes. If you want to use MPOSE2021 for your research work, please also cite [1-11].
@article{mazzia2021action,
title={Action Transformer: A Self-Attention Model for Short-Time Pose-Based Human Action Recognition},
author={Mazzia, Vittorio and Angarano, Simone and Salvetti, Francesco and Angelini, Federico and Chiaberge, Marcello},
journal={Pattern Recognition},
pages={108487},
year={2021},
publisher={Elsevier}
}
[1] Angelini, F., Fu, Z., Long, Y., Shao, L., & Naqvi, S. M. (2019). 2D Pose-Based Real-Time Human Action Recognition With Occlusion-Handling. IEEE Transactions on Multimedia, 22(6), 1433-1446.
[2] Angelini, F., Yan, J., & Naqvi, S. M. (2019, May). Privacy-preserving Online Human Behaviour Anomaly Detection Based on Body Movements and Objects Positions. In ICASSP 2019-2019 IEEE International Conference on Acoustics, Speech and Signal Processing (ICASSP) (pp. 8444-8448). IEEE.
[3] Angelini, F., & Naqvi, S. M. (2019, July). Joint RGB-Pose Based Human Action Recognition for Anomaly Detection Applications. In 2019 22th International Conference on Information Fusion (FUSION) (pp. 1-7). IEEE.
[4] Cao, Z., Hidalgo, G., Simon, T., Wei, S. E., & Sheikh, Y. (2019). OpenPose: Realtime Multi-Person 2D Pose Estimation Using Part Affinity Fields. IEEE transactions on pattern analysis and machine intelligence, 43(1), 172-186.
[5] Gorelick, L., Blank, M., Shechtman, E., Irani, M., & Basri, R. (2007). Actions as Space-Time Shapes. IEEE transactions on pattern analysis and machine intelligence, 29(12), 2247-2253.
[6] Starck, J., & Hilton, A. (2007). Surface Capture for Performance-Based Animation. IEEE computer graphics and applications, 27(3), 21-31.
[7] Weinland, D., Özuysal, M., & Fua, P. (2010, September). Making Action Recognition Robust to Occlusions and Viewpoint Changes. In European Conference on Computer Vision (pp. 635-648). Springer, Berlin, Heidelberg.
[8] Schuldt, C., Laptev, I., & Caputo, B. (2004, August). Recognizing Human Actions: a Local SVM Approach. In Proceedings of the 17th International Conference on Pattern Recognition, 2004. ICPR 2004. (Vol. 3, pp. 32-36). IEEE.
[9] Xia, L., Chen, C. C., & Aggarwal, J. K. (2012, June). View Invariant Human Action Recognition using Histograms of 3D Joints. In 2012 IEEE computer society conference on computer vision and pattern recognition workshops (pp. 20-27). IEEE.
[10] Chen, C., Jafari, R., & Kehtarnavaz, N. (2015, September). UTD-MHAD: A Multimodal Dataset for Human Action Recognition utilizing a Depth Camera and a Wearable Inertial Sensor. In 2015 IEEE International conference on image processing (ICIP) (pp. 168-172). IEEE.
[11] Papandreou, G., Zhu, T., Chen, L. C., Gidaris, S., Tompson, J., & Murphy, K. (2018). Personlab: Person Pose Estimation and Instance Segmentation with a Bottom-Up, Part-Based, Geometric Embedding Model. In Proceedings of the European Conference on Computer Vision (ECCV) (pp. 269-286)
Author correction. Transcriptional dysregulation of interferome in experimental and human multiple sclerosis
No full textThe original version of this Article contained a typographical error in the spelling of the author Eliana M Coccia, which was incorrectly given as Eliana Coccia. This has now been corrected in the PDF and HTML versions of the Article, and in the accompanying Supplementary Material files
Combinatorial polar orderings and recursively orderable arrangements
No full textAbstractPolar orderings arose in recent work of Salvetti and the second author on minimal CW-complexes for complexified hyperplane arrangements. We study the combinatorics of these orderings in the classical framework of oriented matroids, and reach thereby a weakening of the conditions required to actually determine such orderings. A class of arrangements for which the construction of the minimal complex is particularly easy, called recursively orderable arrangements, can therefore be combinatorially defined. We initiate the study of this class, giving a complete characterization in dimension 2 and proving that every supersolvable complexified arrangement is recursively orderable
Performance of the M062X density functional against the ISOL set of benchmark isomerization energies for large organic molecules
No full textGas phase standard state (298.15 K, 1 atm) isomerization energies were calculated using the M062X functional with the QZVP, 6-311++G(d,p), 6-311++G(2d,2p), and cc-pVTZ basis sets against the 24 reactions in the ISOL set of benchmark isomerization energies for large organic molecules. The M062X functional appears to offer comparable isomerization energy prediction performance to the best performing currently available dispersion corrected functionals against this benchmark dataset
A time-variable, phase-dependent emission line in the X-ray spectrum of the isolated neutron star RXJ0822–4300
No full textRX J0822−4300 is the central compact object associated with the Puppis A supernova remnant. Previous X-ray observations suggested RX J0822−4300 to be a young neutron star with a weak dipole field and a peculiar surface temperature distribution dominated by two antipodal spots with different temperatures and sizes. An emission line at 0.8 keV was also detected. We performed a very deep (130-ks) observation with XMM–Newton, which allowed us to study in detail the phase-resolved properties of RX J0822−4300. Our new data confirm the existence of a narrow spectral feature, best modelled as an emission line, only seen in the ‘soft’-phase interval – when the cooler region is best aligned to the line of sight. Surprisingly, comparison of our recent observations to the older ones yields evidence for a variation in the emission-line component, which can be modelled as a decrease in the central energy from ∼0.80 keV in 2001 to ∼0.73 keV in 2009–10. The line could be generated via cyclotron scattering of thermal photons in an optically-thin layer of gas, or, alternatively, it could originate in low-rate accretion by a debris disc. In any case, a variation in energy, pointing to a variation of the magnetic field in the line-emitting region, cannot be easily accounted for
Hopf ring structures on the cohomology of certain spaces
No full text[from the introduction]: The structure of this work is as follows. In the first chapter, we recall the
preliminary notions and results we will make use of, in particular, some facts
regarding Coxeter groups and their classifying spaces, results for the homology
of 1-loop spaces and Hopf rings. The second chapter is devoted to the exposition
of the results involving the cohomology of the symmetric groups. That
chapter basically follows the treatment of two published papers, one by Giusti,
Salvatore and Sinha, and the other by the author of this thesis. In the third
chapter, we calculate the cohomology of the Coxeter groups of Type Bn and
Dn as (almost-)Hopf rings. We also carry on the calculation of the restriction
to elementary abelian subgroups and of the Steenrod algebra action. Finally,
the fourth chapter deals with some results concerning the mod p cohomology
of D(X) and Q(X) for a topological space X
La traduction en Colombie au xixe siècle
No full textL’auteur présente quelques grandes figures des lettres colombiennes du xixe siècle, qui, en plus d’être écrivains et polyglottes, ont aussi été traducteurs. Ces intellectuels ont voulu faire entendre à leurs contemporains la voix de l’Autre et les mettre en contact avec de nouvelles idées et de nouvelles sensibilités de manière à ce qu’ils aient la chance de participer à la sensibilité universelle.The author looks at those 19th century intellectuals who, in addition to being writers and polyglots, were also translators: men driven by the need to introduce their fellow countrymen to the voice of the Other, to new ideas and to the chance to become active subjects of new universal sensibility
