3,091 research outputs found
Adaptive Critic Design for Energy Minimization of Portable Video Communication Devices
DOI: 10.1109/ICCCN.2008.ECP.70Portable video communication devices operate on
batteries with limited energy supply. However, video compression is computationally intensive and energy-demanding. Therefore, one of the central challenging issues in portable video
communication system design is to minimize the energy consumption of video encoding so as to prolong the operational lifetime of portable video devices. In this work, we consider a
video encoder as a nonlinear system with a number of encoder parameters to its power consumption. We explore the approach of adaptive critic design to control and optimize the power consumption behavior of a portable video encoding system. Our experimental results demonstrate that this approach is very
efficiently, being able to achieve the optimum performance accurately and robustly.This work has been supported in part by NSF under grant DBI-0529082
Shape Completion with Points in the Shadow
Single-view point cloud completion aims to recover the full geometry of an
object based on only limited observation, which is extremely hard due to the
data sparsity and occlusion. The core challenge is to generate plausible
geometries to fill the unobserved part of the object based on a partial scan,
which is under-constrained and suffers from a huge solution space. Inspired by
the classic shadow volume technique in computer graphics, we propose a new
method to reduce the solution space effectively. Our method considers the
camera a light source that casts rays toward the object. Such light rays build
a reasonably constrained but sufficiently expressive basis for completion. The
completion process is then formulated as a point displacement optimization
problem. Points are initialized at the partial scan and then moved to their
goal locations with two types of movements for each point: directional
movements along the light rays and constrained local movement for shape
refinement. We design neural networks to predict the ideal point movements to
get the completion results. We demonstrate that our method is accurate, robust,
and generalizable through exhaustive evaluation and comparison. Moreover, it
outperforms state-of-the-art methods qualitatively and quantitatively on MVP
datasets.Comment: SIGGRAPH Aisa 2022 Conference Pape
Reconstructing 3D Human Pose from RGB-D Data with Occlusions
We propose a new method to reconstruct the 3D human body from RGB-D images
with occlusions. The foremost challenge is the incompleteness of the RGB-D data
due to occlusions between the body and the environment, leading to implausible
reconstructions that suffer from severe human-scene penetration. To reconstruct
a semantically and physically plausible human body, we propose to reduce the
solution space based on scene information and prior knowledge. Our key idea is
to constrain the solution space of the human body by considering the occluded
body parts and visible body parts separately: modeling all plausible poses
where the occluded body parts do not penetrate the scene, and constraining the
visible body parts using depth data. Specifically, the first component is
realized by a neural network that estimates the candidate region named the
"free zone", a region carved out of the open space within which it is safe to
search for poses of the invisible body parts without concern for penetration.
The second component constrains the visible body parts using the "truncated
shadow volume" of the scanned body point cloud. Furthermore, we propose to use
a volume matching strategy, which yields better performance than surface
matching, to match the human body with the confined region. We conducted
experiments on the PROX dataset, and the results demonstrate that our method
produces more accurate and plausible results compared with other methods
NLTGCR: A class of Nonlinear Acceleration Procedures based on Conjugate Residuals
This paper develops a new class of nonlinear acceleration algorithms based on
extending conjugate residual-type procedures from linear to nonlinear
equations. The main algorithm has strong similarities with Anderson
acceleration as well as with inexact Newton methods - depending on which
variant is implemented. We prove theoretically and verify experimentally, on a
variety of problems from simulation experiments to deep learning applications,
that our method is a powerful accelerated iterative algorithm.Comment: Under Revie
Sorafenib modulates the radio sensitivity of hepatocellular carcinoma cells in vitro in a schedule-dependent manner
BACKGROUND: Hepatocellular carcinoma (HCC) has a high incidence and mortality. Radiotherapy and sorafenib have proven effective for HCC. Here, we investigated whether sorafenib modulated the response of HCC cells to irradiation in vitro, effect of timing of sorafenib, and the underlying mechanisms. METHODS: Cell viability of the HCC cell lines, SMMC-7721 and Bel-7402, was examined by the 3-(4,5-dimethylthiazol-2-yl)-5(3-carboxymethoxyphenyl)-2(4-sulfophenyl)-2 H-terazolium (MTT) assays. Clonogenic growth assays of SMMC-7721 and Bel-7402 were determined by colony formation assays. DNA damage was assessed by monitoring γ-HAX foci in irradiated cells with immunofluorescence microscopy, and cell cycle distribution changes were examined by flow cytometry. Effects of sorafenib (15 μM) added 30 min prior to radiation (pre-irradiation sorafenib) of SMMC-7721 and BEL-7402 or 24 h post-irradiation (post-irradiation sorafenib) on irradiated SMMC-7721 and BEL-7402 cells were compared to those of radiation alone or no treatment. RESULTS: The effect of sorafenib was dependent on its time of addition in relationship to irradiation of cells. Pre-irradiation sorafenib did not significantly affect the viability of SMMC-7221 and BEL-7402 cells compared with irradiation treatment alone. In contrast, post-irradiation sorafenib increased the sensitivity of irradiated SMMC-7221 and BEL-7402 cells significantly in a time-dependent manner. Pre-irradiation sorafenib significantly increased the surviving fraction of SMMC-7221 and BEL-7402 cells in clonogenic assays whereas post-irradiation sorafenib significantly reduced the surviving fractions of SMMC-7221 and BEL-7402 cells. SMMC-7721 cells treated with sorafenib 30 min before irradiation had significantly fewer cells with γ-H2AX foci (23.8 ± 2.9%) than SMMC-7721 cells receiving radiation alone (59.9 ± 2.4; P < 0.001). Similarly, BEL-7402 cells receiving sorafenib prior to irradiation had significantly fewer cells with γ-H2AX foci (46.4 ± 3.8%) than those receiving radiation alone (25.0 ± 3.0%; P < 0.001). In addition, irradiation (6 Gy) caused a significant increase in the percentage of both SMMC-7721 and BEL-7402 cells in G2/M at 12 to 16 h post irradiation, which was markedly delayed by pre-irradiation sorafenib. CONCLUSIONS: Sorafenib combined with irradiation exerted a schedule-dependent effect in HCC cells in vitro, which has significant implications for the combined use of sorafenib and radiotherapy for HCC patients
Association of IL-10 polymorphisms with hepatitis B virus infection and outcome in Han population
Increased expression of collagens, transforming growth factor-β1, and -β3 in gluteal muscle contracture
<p>Abstract</p> <p>Backgroud</p> <p>Gluteal muscle contracture (GMC) is a multi-factor human chronic fibrotic disease of the gluteal muscle. Fibrotic tissue is characterized by excessive accumulation of collagen in the muscle's extracellular matrix. Transforming growth factor (TGF)-β1 and -β2 are thought to play an important role in fibrogenesis, while TGF-β3 is believed to have an anti-fibrotic function. We hypothesize that the expression of collagen and TGF-βs would be up-regulated in GMC patients.</p> <p>Methods</p> <p>The expression of collagen type I, type III and TGF-βs were studied in 23 fibrotic samples and 23 normal/control samples in GMC patients using immunohistochemistry, reverse transcription and polymerase chain reaction (RT-PCR) and western bolt analysis.</p> <p>Results</p> <p>Compared to the unaffected adjacent muscle, increased expression of TGF-β1 and -β3 was associated with deposition of collagen type I and type III in the fibrotic muscle of the GMC patients at the mRNA level. Strong up-regulation of these proteins in fibrotic muscle was confirmed by immunohistochemical staining and western blot analysis. TGF-β2 was not up-regulated in relation to GMC.</p> <p>Conclusion</p> <p>This study confirmed our hypothesis that collagen types I, III, TGF-β1 and TGF-β3 were up-regulated in biopsy specimens obtained from patients with GMC. Complex interaction of TGF-β1 with profibrotic function and TGF-β3 with antifibrotic function may increase synthesis of collagens and thereby significantly contribute to the process of gluteal muscle scarring in patients with GMC.</p
Molecular Beam Epitaxy Growth of Superconducting LiFeAs Film on SrTiO3(001) Substrate
The stoichiometric "111" iron-based superconductor, LiFeAs, has attacted
great research interest in recent years. For the first time, we have
successfully grown LiFeAs thin film by molecular beam epitaxy (MBE) on
SrTiO3(001) substrate, and studied the interfacial growth behavior by
reflection high energy electron diffraction (RHEED) and low-temperature
scanning tunneling microscope (LT-STM). The effects of substrate temperature
and Li/Fe flux ratio were investigated. Uniform LiFeAs film as thin as 3
quintuple-layer (QL) is formed. Superconducting gap appears in LiFeAs films
thicker than 4 QL at 4.7 K. When the film is thicker than 13 QL, the
superconducting gap determined by the distance between coherence peaks is about
7 meV, close to the value of bulk material. The ex situ transport measurement
of thick LiFeAs film shows a sharp superconducting transition around 16 K. The
upper critical field, Hc2(0)=13.0 T, is estimated from the temperature
dependent magnetoresistance. The precise thickness and quality control of
LiFeAs film paves the road of growing similar ultrathin iron arsenide films.Comment: 7 pages, 6 figure
AquaÂ(2,2′-bipyrimidine-κ2 N,N′)(succinÂato-κ2 O 1,O 4)copper(II) dihydrate
In the crystal structure of the title compound, [Cu(C4H4O4)(C8H6N4)(H2O)]·2H2O, the CuII atom is chelated by a 2,2′-bipyrimidine (bpm) ligand and a succinate anion in the basal plane; a water molÂecule in the apical position completes the slightly distorted square-pyramidal coordination geometry. Another carboxylÂate O atom from an adjacent complex is located in the opposite apical direction, with a Cu⋯O distance of 2.706 (3) Å, and is not considered as a bridging atom. Extensive O—H⋯O and O—H⋯N hydrogen bonding is present in the crystal structure
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