4,181 research outputs found
Dictionary-based Tensor Canonical Polyadic Decomposition
To ensure interpretability of extracted sources in tensor decomposition, we
introduce in this paper a dictionary-based tensor canonical polyadic
decomposition which enforces one factor to belong exactly to a known
dictionary. A new formulation of sparse coding is proposed which enables high
dimensional tensors dictionary-based canonical polyadic decomposition. The
benefits of using a dictionary in tensor decomposition models are explored both
in terms of parameter identifiability and estimation accuracy. Performances of
the proposed algorithms are evaluated on the decomposition of simulated data
and the unmixing of hyperspectral images
Spectral Unmixing with Multiple Dictionaries
Spectral unmixing aims at recovering the spectral signatures of materials,
called endmembers, mixed in a hyperspectral or multispectral image, along with
their abundances. A typical assumption is that the image contains one pure
pixel per endmember, in which case spectral unmixing reduces to identifying
these pixels. Many fully automated methods have been proposed in recent years,
but little work has been done to allow users to select areas where pure pixels
are present manually or using a segmentation algorithm. Additionally, in a
non-blind approach, several spectral libraries may be available rather than a
single one, with a fixed number (or an upper or lower bound) of endmembers to
chose from each. In this paper, we propose a multiple-dictionary constrained
low-rank matrix approximation model that address these two problems. We propose
an algorithm to compute this model, dubbed M2PALS, and its performance is
discussed on both synthetic and real hyperspectral images
Resegmentation is an ancestral feature of the gnathostome vertebral skeleton
© The Author(s), 2020. This article is distributed under the terms of the Creative Commons Attribution License. The definitive version was published in Criswell, K. E., & Gillis, J. A. Resegmentation is an ancestral feature of the gnathostome vertebral skeleton. Elife, 9, (2020): e51696, doi:10.7554/elife.51696.The vertebral skeleton is a defining feature of vertebrate animals. However, the mode of vertebral segmentation varies considerably between major lineages. In tetrapods, adjacent somite halves recombine to form a single vertebra through the process of ‘resegmentation’. In teleost fishes, there is considerable mixing between cells of the anterior and posterior somite halves, without clear resegmentation. To determine whether resegmentation is a tetrapod novelty, or an ancestral feature of jawed vertebrates, we tested the relationship between somites and vertebrae in a cartilaginous fish, the skate (Leucoraja erinacea). Using cell lineage tracing, we show that skate trunk vertebrae arise through tetrapod-like resegmentation, with anterior and posterior halves of each vertebra deriving from adjacent somites. We further show that tail vertebrae also arise through resegmentation, though with a duplication of the number of vertebrae per body segment. These findings resolve axial resegmentation as an ancestral feature of the jawed vertebrate body plan.Royal Society (NF160762)
Katharine E Criswell
Royal Society (UF130182)
J. Andrew Gillis
Marine Biological Laboratory
Katharine E. Criswel
Alien Registration- Gillis, Bartholomew E. (Portland, Cumberland County)
https://digitalmaine.com/alien_docs/24130/thumbnail.jp
Transverse (Harris) lines in the tibiae of a prehistoric Costa Rican population
Transverse (Harris) lines are lines of opacity that extend across the medullary cavity in long bones; they are sometimes are also found in irregular bones. Predominantly, Harris lines are seen in radiographs of the tibiae. Many scholars believe that these lines of opacity are caused by nutritional interruptions during growth, while others believe these lines to be indicators of stress recovery, rather than interruption. This study examines the incidence of transverse lines in a Pre-Columbian Costa Rican population, called Vidor, located on the northwest Bay of Culebra. The burials of this population, originally excavated in 1977, contained more than 40 skeletons. Subsequent excavations at the site revealed a total of 192 individuals, most of which were juveniles and neonates and dated as far back as A.D. 300. Tibiae and ilia from 39 individuals of the Vidor population were radiographed in order to determine if any transverse lines were present and, if so, what the implications of nutritional status might be. The results showed that none of the ilia revealed any transverse lines in the x-rays and only seven of the tibiae exhibited opacities. Two of the seven tibiae exhibiting transverse lines contained multiple lines. A study conducted on the Vidor population by Obando (1995) included analysis of enamel hypoplasias and cortical bone thickness. The study showed that there were high frequencies of enamel hypoplasias and a loss of cortical bone starting as early as 1.0 years of age and lasting until six years of age, coinciding with weaning ages. Obando’s study concluded that there were some nutritional deficiencies occurring in the Vidor population. The current study on transverse lines did not produce the same results. This study showed that, while there were some bands of opacity occurring in the tibiae, they could not be directly attributed to a dietary response
Dynamics of coreless vortices and rotation-induced dissipation peak in superfluid films on rotating porous substrates
We analyze dynamics of 3D coreless vortices in superfluid films covering
porous substrates. The 3D vortex dynamics is derived from the 2D dynamics of
the film. The motion of a 3D vortex is a sequence of jumps between neighboring
substrate cells, which can be described, nevertheless, in terms of
quasi-continuous motion with average vortex velocity. The vortex velocity is
derived from the dissociation rate of vortex-antivortex pairs in a 2D film,
which was developed in the past on the basis of the Kosterlitz-Thouless theory.
The theory explains the rotation-induced dissipation peak in torsion-oscillator
experiments on He films on rotating porous substrates and can be used in
the analysis of other phenomena related to vortex motion in films on porous
substrates.Comment: 8 pages, 3 figures submitted to Phys. Rev.
The Distribution Implications of the Taxation of Natural Resources
Paper by Malcolm Gillis and Charles E. McLure, Jr
Oxygen sorbent
The present invention discloses a novel and unique family of agents which reversibly binds molecular oxygen at room temperature
An Economic Analysis of Contributions under the Income Tax Laws
In this note classical tools are used to examine the treatment of gifts in kind under the federal income-tax laws as they were but a few years ago, as they are today, and as they should be, given the objective that the law appears to be trying to achieve. It will be demonstrated that, under certain conditions, firms today can maximize profit after taxes by producing some output to be given to acceptable charities
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