316 research outputs found
Quality improving techniques in DIBR for free-viewpoint video
This paper evaluates our 3D view interpolation rendering algorithm and proposes a few performance improving techniques. We aim at developing a rendering method for free-viewpoint 3DTV, based on depth image warping from surrounding cameras. The key feature of our approach is warping texture and depth in the first stage simultaneously and postpone blending the new view to a later stage, thereby avoiding errors in the virtual depth map. We evaluate the rendering quality in two ways. Firstly, it is measured by varying the distance between the two nearest cameras. We have obtained a PSNR gain of 3 dB and 4.5 dB for the 'Breakdancers' and 'Ballet' sequences, respectively, compared to the performance of a recent algorithm. A second series of tests in measuring the rendering quality were performed using compressed video or images from surrounding cameras. The overall quality of the system is dominated by rendering quality and not by coding
Preventing Pseudomonas aeruginosa and Chromobacterium violaceum infections by anti-adhesion-active components of edible seeds
<p>Abstract</p> <p>Background</p> <p><it>Pseudomonas aeruginosa </it>adhesion to animal/human cells for infection establishment involves adhesive proteins, including its galactose- and fucose-binding lectins PA-IL (LecA) and PA-IIL (LecB). The lectin binding to the target-cell receptors may be blocked by compatible glycans that compete with those of the receptors, functioning as anti-adhesion glycodecoys. The anti-adhesion treatment is of the utmost importance for abrogating devastating antibiotic-resistant <it>P. aeruginosa </it>infections in immunodeficient and cystic fibrosis (CF) patients. This strategy functions in nature in protecting embryos and neonates. We have shown that PA-IL, PA-IIL, and also CV-IIL (a PA-IIL homolog produced in the related pathogen <it>Chromobacterium violaceum</it>) are highly useful for revealing natural glycodecoys that surround embryos in diverse avian eggs and are supplied to neonates in milks and royal jelly. In the present study, these lectins were used as probes to search for seed embryo-protecting glycodecoys.</p> <p>Methods</p> <p>The lectin-blocking glycodecoy activities were shown by the hemagglutination-inhibition test. Lectin-binding glycoproteins were detected by Western blotting with peroxidase-labeled lectins.</p> <p>Results</p> <p>The present work reports the finding - by using PA-IL, PA-IIL, and CV-IIL - of rich glycodecoy activities of low (< 10 KDa) and high MW (> 10 kDa) compounds (including glycoproteins) in extracts of cashew, cocoa, coffee, pumpkin, and tomato seeds, resembling those of avian egg whites, mammal milks, and royal jelly.</p> <p>Conclusions</p> <p>Edible seed extracts possess lectin-blocking glycodecoys that might protect their embryos from infections and also might be useful for hampering human and animal infections.</p
Формирование зонной диаграммы фотонных и фононных кристаллов
Досліджено зонні особливості вхідних імпедансних характеристик необмежених і обмежених фотонного та фононного кристалів (Ф(н)К). Взаємним порівнянням залежностей коефіцієнта відбиття обмежених Ф(н)К і активної складової вхідного імпедансу необмежених Ф(н)К проаналізовано формування зонної діаграми обмеженими Ф(н)К. В результаті аналізу залежності параметрів заборонених зон обмежених Ф(н)К від кількості шарів проаналізовано степінь наближення параметрів зонної діаграми обмежених Ф(н)К до параметрів зонної діаграми необмежених Ф(н)К.Inroduction. Photon and phonon crystals are crystal structures, which just like the crystals, are characterized by zone spectral properties. The purpose of the article is to research the input impedance characteristics and formation features of the photon and phonon crystals’ zone diagrams. Impedance model and properties of unlimited crystal structure. The expressions for input impedance of unlimited one-dimensional crystal structure for waves of different nature are presented. The relationships of physical properties of the crystal structure and the mathematical features of the expressions are investigated. Impedance characteristics of photon and phonon unlimited crystals. The dependences of active and reactive components of photon and phonon unlimited crystal’s input impedance with layers of different thickness are shown. Input impedance characteristics of photon and phonon limited crystals. The dependences of active and reactive components of limited photon and phonon crystal’s input impedance are given. The conditions for waves resonant passing through photon and phonon crystals are obtained. Reflection coefficient characteristics of photon and phonon crystals. The formation of the limited photon and phonon crystal’s zone diagrams is analyzed by mutual comparison of limited photon and phonon crystal’s reflection characteristic and active component of unlimited photon and phonon crystal’s input impedance characteristics. The approximation degree of limited photon and phonon crystal’s zone diagram parameters to the unlimited photon and phonon crystal’s zone diagram parameters is quantitatively analyzed.
Conclusions. The conditions for waves resonant passing through photon and phonon crystals is formulated and features of photon and phonon crystal’s zone diagram formation is investigated.Исследованы зонные особенности входных импедансных характеристик неограниченных и ограниченных фотонного и фононного кристаллов (Ф(н)К). Взаимным сравнением зависимостей коэффициента отражения ограниченных Ф(н)К и активной составляющей входного импеданса неограниченных Ф(н)К проанализировано формирование зонной диаграммы ограниченными Ф(н)К. В результате анализа зависимости параметров запрещенных зон ограниченных Ф(н)К от числа слоев проанализирована степень приближения параметров зонной диаграммы ограниченных Ф(н)К к параметрам зонной диаграммы неограниченных Ф(н)К
The universe formation by a space reduction cascade with random initial parameters
In this paper we discuss the creation of our universe using the idea of extra
dimensions. The initial, multidimensional Lagrangian contains only metric
tensor. We have found many sets of the numerical values of the Lagrangian
parameters corresponding to the observed low-energy physics of our universe.
Different initial parameters can lead to the same values of fundamental
constants by the appropriate choice of a dimensional reduction cascade. This
result diminishes the significance of the search for the 'unique' initial
Lagrangian. We also have obtained a large number of low-energy vacua, which is
known as a 'landscape' in the string theory.Comment: 17 pages, 1 figur
Constructing Impactful Machine Learning Research for Astronomy: Best Practices for Researchers and Reviewers
Machine learning has rapidly become a tool of choice for the astronomical
community. It is being applied across a wide range of wavelengths and problems,
from the classification of transients to neural network emulators of
cosmological simulations, and is shifting paradigms about how we generate and
report scientific results. At the same time, this class of method comes with
its own set of best practices, challenges, and drawbacks, which, at present,
are often reported on incompletely in the astrophysical literature. With this
paper, we aim to provide a primer to the astronomical community, including
authors, reviewers, and editors, on how to implement machine learning models
and report their results in a way that ensures the accuracy of the results,
reproducibility of the findings, and usefulness of the method.Comment: 14 pages, 3 figures; submitted to the Bulletin of the American
Astronomical Societ
Cold streams in early massive hot haloes as the main mode of galaxy formation
The massive galaxies in the young universe, ten billion years ago, formed
stars at surprising intensities. Although this is commonly attributed to
violent mergers, the properties of many of these galaxies are incompatible with
such events, showing gas-rich, clumpy, extended rotating disks not dominated by
spheroids (Genzel et al. 2006, 2008). Cosmological simulations and clustering
theory are used to explore how these galaxies acquired their gas. Here we
report that they are stream-fed galaxies, formed from steady, narrow, cold gas
streams that penetrate the shock-heated media of massive dark matter haloes
(Dekel & Birnboim 2006; Keres et al. 2005). A comparison with the observed
abundance of star-forming galaxies implies that most of the input gas must
rapidly convert to stars. One-third of the stream mass is in gas clumps leading
to mergers of mass ratio greater than 1:10, and the rest is in smoother flows.
With a merger duy cycle of 0.1, three-quarters of the galaxies forming stars at
a given rate are fed by smooth streams. The rarer, submillimetre galaxies that
form stars even more intensely are largely merger-induced starbursts. Unlike
destructive mergers, the streams are likely to keep the rotating disk
configuration intact, although turbulent and broken into giant star-forming
clumps that merge into a central spheroid (Noguchi 1999; Genzel et al. 2008,
Elmegreen, Bournaud & Elmegreen 2008, Dekel, Sari & Ceverino 2009). This
stream-driven scenario for the formation of disks and spheroids is an
alternative to the merger picture.Comment: Improved version, 25 pages, 13 figures, Letter to Nature with
Supplementary Informatio
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