Hasil untuk "Property"

Mathilde Caron, Hugo Touvron, Ishan Misra et al.

In this paper, we question if self-supervised learning provides new properties to Vision Transformer (ViT) [16] that stand out compared to convolutional networks (convnets). Beyond the fact that adapting self-supervised methods to this architecture works particularly well, we make the following observations: first, self-supervised ViT features contain explicit information about the semantic segmentation of an image, which does not emerge as clearly with supervised ViTs, nor with convnets. Second, these features are also excellent k-NN classifiers, reaching 78.3% top-1 on ImageNet with a small ViT. Our study also underlines the importance of momentum encoder [26], multi-crop training [9], and the use of small patches with ViTs. We implement our findings into a simple self-supervised method, called DINO, which we interpret as a form of self-distillation with no labels. We show the synergy between DINO and ViTs by achieving 80.1% top-1 on ImageNet in linear evaluation with ViT-Base.

K. Weick

The Nature of Sensemaking Seven Properties of Sensemaking Sensemaking in Organizations Occasions for Sensemaking The Substance of Sensemaking Belief-Driven Processes of Sensemaking Action-Driven Processes of Sensemaking The Future of Sensemaking

I. Aranaz, A. Alcántara, M. Civera et al.

Chitosan has garnered much interest due to its properties and possible applications. Every year the number of publications and patents based on this polymer increase. Chitosan exhibits poor solubility in neutral and basic media, limiting its use in such conditions. Another serious obstacle is directly related to its natural origin. Chitosan is not a single polymer with a defined structure but a family of molecules with differences in their composition, size, and monomer distribution. These properties have a fundamental effect on the biological and technological performance of the polymer. Moreover, some of the biological properties claimed are discrete. In this review, we discuss how chitosan chemistry can solve the problems related to its poor solubility and can boost the polymer properties. We focus on some of the main biological properties of chitosan and the relationship with the physicochemical properties of the polymer. Then, we review two polymer applications related to green processes: the use of chitosan in the green synthesis of metallic nanoparticles and its use as support for biocatalysts. Finally, we briefly describe how making use of the technological properties of chitosan makes it possible to develop a variety of systems for drug delivery.

Annie T. Ginty

H. Flemming, J. Wingender, U. Szewzyk et al.

T. Ho, Chin-Chuan Chang, Hung-Pin Chan et al.

Hydrogels are crosslinked polymer chains with three-dimensional (3D) network structures, which can absorb relatively large amounts of fluid. Because of the high water content, soft structure, and porosity of hydrogels, they closely resemble living tissues. Research in recent years shows that hydrogels have been applied in various fields, such as agriculture, biomaterials, the food industry, drug delivery, tissue engineering, and regenerative medicine. Along with the underlying technology improvements of hydrogel development, hydrogels can be expected to be applied in more fields. Although not all hydrogels have good biodegradability and biocompatibility, such as synthetic hydrogels (polyvinyl alcohol, polyacrylamide, polyethylene glycol hydrogels, etc.), their biodegradability and biocompatibility can be adjusted by modification of their functional group or incorporation of natural polymers. Hence, scientists are still interested in the biomedical applications of hydrogels due to their creative adjustability for different uses. In this review, we first introduce the basic information of hydrogels, such as structure, classification, and synthesis. Then, we further describe the recent applications of hydrogels in 3D cell cultures, drug delivery, wound dressing, and tissue engineering.

K. Yasumatsu, K. Sawada, S. Moritaka et al.

L. Barsalou

S. Benson, J. H. Buss

S. Owicki, L. Lamport

Z. Mohammadi, P. Abbott

S. Lauritzen, A. Dawid, B. N. Larsen et al.

Dalya Baron, Karin M. Sandstrom, Jessica Sutter et al.

The structure and chemistry of the dusty interstellar medium (ISM) are shaped by complex processes that depend on the local radiation field, gas composition, and dust grain properties. Of particular importance are polycyclic aromatic hydrocarbons (PAHs), which emit strong vibrational bands in the mid-infrared, and play a key role in the ISM energy balance. We recently identified global correlations between PAH band and optical line ratios across three nearby galaxies, suggesting a connection between PAH heating and gas ionization throughout the ISM. In this work, we perform a census of the PAH heating–gas ionization connection using ∼700,000 independent pixels that probe scales of 40–150 pc in 19 nearby star-forming galaxies from the PHANGS survey. We find a universal relation between $\mathrm{log}$ PAH(11.3 μ m/7.7 μ m) and $\mathrm{log}$ ([S ii ]/H α ) with a slope of ∼0.2 and a scatter of ∼0.025 dex. The only exception is a group of anomalous pixels that show unusually high (11.3 μ m/7.7 μ m) PAH ratios in regions with old stellar populations and high starlight-to-dust emission ratios. Their mid-infrared spectra resemble those of elliptical galaxies. Active galactic nucleus hosts show modestly steeper slopes, with a ∼​​​​​​10% increase in PAH(11.3 μ m/7.7 μ m) in the diffuse gas on kiloparsec scales. This universal relation implies an emerging simplicity in the complex ISM, with a sequence that is driven by a single varying property: the spectral shape of the interstellar radiation field. This suggests that other properties, such as gas-phase abundances, gas ionization parameter, and grain charge distribution, are relatively uniform in all but specific cases.

J. Bicerano

Hannes Jakob

We define forcing orders which add witnesses to the failure of various forms of Friedman's Property. These posets behave similarly to the forcing order adding a nonreflecting stationary set but have the advantage of allowing the construction of master conditions and thus the preservation of various large cardinal properties. We apply these new techniques to separate various instances of variants of Friedman's Problem, both between different instances at one cardinal as well as equal instances at different cardinals and en passant obtain some new results regarding the differences between ${<}\,κ$- and $κ$-strategic closure.

Abraham Rueda Zoca

In this note we study the inheritance of the slice diameter two property by ultrapower spaces. Given a Banach space $X$, we give a characterisation of when $(X)_\mathcal U$, the ultrapower of $X$ through a free ultrafilter $\mathcal U$, has the slice diameter two property obtaining that this is the case for many Banach spaces which are known to enjoy the slice diameter two property. We also provide, for every $η>0$, an example of a Banach space $X$ with the Daugavet property such that the unit ball of $(X)_\mathcal U$ contains a slice of diameter smaller than $η$ for every free ultrafilter $\mathcal U$ over $\mathbb N$. This proves, in particular, that the slice diameter two property is not in general inherited by taking ultrapower spaces.

Bingxue Tao

Using the projection complex machinery, Bestvina-Bromberg-Fujiwara, Hagen-Petyt and Han-Nguyen-Yang prove that several classes of nonpositively-curved groups admit equivariant quasi-isometric embeddings into finite products of quasi-trees, i.e. having property (QT). In this paper, we unify and generalize the above results by establishing a sufficient condition for relatively hierarchically hyperbolic groups to have property (QT). As applications, we show that a group has property (QT) if it is residually finite and belongs to one of the following classes of groups: admissible groups, hyperbolic--$2$--decomposable groups with no distorted elements, Artin groups of large and hyperbolic type. We also introduce a slightly stronger version of property (QT), called property (QT'), and show the invariance of property (QT') under graph products.

Larisa B. Mandzhikova

Introduction. The mid-to-late nineteenth century was witnessing further integration of Kalmyk Steppe and its society into the Russian state system. During the period under review, it was the Horde [Affairs] Department at Astrakhan Chamber of State Property (1848–1881) that became in charge of the administrative reform, with activities guided by the Kalmyk People’s Governance Regulations of 23 April 1847. The agency’s documents had compiled Collection И-6 (‘Horde [Affairs] Department at Astrakhan Chamber of State Property, 1832–1881’) at the National Archive of Kalmykia. Goals. The study seeks to investigate the reference apparatus to Collection И-6, analyze its structure and types of documents, identify common and distinctive features in record keeping at the newly created government body after the introduction of the 1847 Regulations, and the former’s source potential for historical research of state institutions in prerevolutionary Kalmykia. Results. The Regulations of 1847 established a clear division of powers between the Governor’s Office and Kalmyk elites, and sought to articulate certain division of powers in Kalmyk self-governance too. The Regulations specified directions of activity for structural units of the Horde [Affairs] Department, which had its impacts on workflow management essentials of the Kalmyk people’s governing body. The documents that resulted from the latter’s activities are related to official record keeping and their formatting patterns meet the requirements of that era. The archival documents included in Collection И-6 are a valuable source for further historical insights into how local public institutions in Russia would develop throughout the prerevolutionary period, and how Kalmykia’s administrative structures would evolutionize accordingly.

Tianzhen Liu, Wei Zhao, Yongtao Yao et al.

Triply periodic minimal surface (TPMS) structures with excellent properties of stable energy absorption, light weight, and high specific strength could potentially spark immense interest for novel and programmable functions by combining smart materials, e.g. shape memory polymers (SMPs). This work proposes TPMS lattices with hybrid configurations and materials that are composed of viscoelastic and shape-memory materials with the aim to bring temperature-dependent mechanical properties and additional dissipation mechanisms. Different configurations and diverse materials of polylactic acid (PLA), fiber-reinforced PLA, and polydimethylsiloxane (PDMS) are induced, generating five types of TPMS lattices, including (Schoen’s I-WP) IWP uniform lattice, IWP lattice with density gradient, hybrid configurations, hybrid materials, and filled PDMS, which are fabricated by 3D printing. The fracture morphologies and the distribution of carbon fibers are demonstrated via scanning electron microscopy with a focus on the influence of carbon fiber on shape-memory and mechanical properties. Shape recovery tests are conducted, which proves good shape memory properties and reusable capability of TPMS lattice. The combined methods of experiments and numerical simulation are adopted to evaluate mechanical properties, which presents multi-stage energy absorption ability and tunable vibration isolation performances associated with temperature and hybridization designs. This work can promote extensive research and provide substantial opportunities for TPMS lattices in the development of functional applications.

A. Bicchi