1,263 research outputs found
A Method of Experimentally Probing Transeverse Momentum Dependent Distributions
We calculate the double spin asymmetry A_LL(x, y, z, P_hT) of pi^0 production
with the spectator model and the model based on the factorization ansatz. We
also calculate the double spin asymmetry for the integration over the range of
(x,y,z) for the setups of the experiments of COMPASS, HERMES, and JLab. We find
that the results are characteristically dependent on the model used. Therefore,
we suggest that the measurements of the double spin asymmetry provides a method
of experimentally probing the transeverse momentum dependent distributions.Comment: 10 pages, 31 figure
Improved Real-Time Monocular SLAM Using Semantic Segmentation on Selective Frames
Monocular simultaneous localization and mapping (SLAM) is emerging in
advanced driver assistance systems and autonomous driving, because a single
camera is cheap and easy to install. Conventional monocular SLAM has two major
challenges leading inaccurate localization and mapping. First, it is
challenging to estimate scales in localization and mapping. Second,
conventional monocular SLAM uses inappropriate mapping factors such as dynamic
objects and low-parallax areas in mapping. This paper proposes an improved
real-time monocular SLAM that resolves the aforementioned challenges by
efficiently using deep learning-based semantic segmentation. To achieve the
real-time execution of the proposed method, we apply semantic segmentation only
to downsampled keyframes in parallel with mapping processes. In addition, the
proposed method corrects scales of camera poses and three-dimensional (3D)
points, using estimated ground plane from road-labeled 3D points and the real
camera height. The proposed method also removes inappropriate corner features
labeled as moving objects and low parallax areas. Experiments with eight video
sequences demonstrate that the proposed monocular SLAM system achieves
significantly improved and comparable trajectory tracking accuracy, compared to
existing state-of-the-art monocular and stereo SLAM systems, respectively. The
proposed system can achieve real-time tracking on a standard CPU potentially
with a standard GPU support, whereas existing segmentation-aided monocular SLAM
does not
The Interaction of Phospholipase C-{beta}3 with Shank2 Regulates mGluR-mediated Calcium Signal
Phospholipase C-{beta} isozymes that are activated by G protein-coupled receptors (GPCR) and heterotrimeric G proteins carry a PSD-95/Dlg/ZO-1 (PDZ) domain binding motif at their C terminus. Through interactions with PDZ domains, this motif may endow the PLC-{beta} isozyme with specific roles in GPCR signaling events that occur in compartmentalized regions of the plasma membrane. In this study, we identified the interaction of PLC-{beta}3 with Shank2, a PDZ domain-containing multimodular scaffold in the postsynaptic density (PSD). The C terminus of PLC-{beta}3, but not other PLC-{beta} isotypes, specifically interacts with the PDZ domain of Shank2. Homer 1b, a Shank-interacting protein that is linked to group I metabotropic glutamate receptors and IP3 receptors, forms a multiple complex with Shank2 and PLC-{beta}3. Importantly, microinjection of a synthetic peptide specifically mimicking the C terminus of PLC-{beta}3 markedly reduces the mGluR-mediated intracellular calcium response. These results demonstrate that Shank2 brings PLC-{beta}3 closer to Homer 1b and constitutes an efficient mGluR-coupled signaling pathway in the PSD region of neuronal synapses
Multiuser diversity and multiplexing using multiple random beams in wireless systems
In this paper, we propose a new multiple-antenna transmission scheme that can simultaneously achieve both diversity
and multiplexing gain in the multi-user domain, by using multiple random beams. Multiple beams are generated so that
the users encounter multiple channels at the same time, enabling the use of multi-user diversity through each channel. Although
the signal-to-noise power ratio (SNR) of each channel is reduced in proportion to the number of beams, multiple beams are
generated so that the multiplexing gain is larger than the decrease of SNR, increasing the overall system capacity
A novel downlink beamforming scheme for FDD/SDMA systems
When beamforming is employed in the uplink without feedback channel, the beam pattern for the downlink can be generated using the weight used for uplink beamforming. However, this scheme may result in significantly performance degradation in the frequency division duplex (FDD) because of carrier frequency offset between the uplink and downlink. In this paper we propose a novel downlink beamforming algorithm based on least square method with some constraint points which have same gain in the up/downlink beam pattern. From the constraint points, we generate downlink weight and also propose how to choose the constraint points in order to satisfy the desired signal-to-interference power ratio. Simulation results show that the proposed method can sufficiently reduce the interference from other space division multiple access (SDMA) signals, providing interference-free spatial channel
To the Edge of M87 and Beyond: Spectroscopy of Intracluster Globular Clusters and Ultra Compact Dwarfs in the Virgo Cluster
We present the results from a wide-field spectroscopic survey of globular
clusters (GCs) in the Virgo Cluster. We obtain spectra for 201 GCs and 55
ultracompact dwarfs (UCDs) using the Hectospec on the Multiple Mirror
Telescope, and derive their radial velocities. We identify 46 genuine
intracluster GCs (IGCs), not associated with any Virgo galaxies, using the 3D
GMM test on the spatial and radial velocity distribution.They are located at
the projected distance 200 kpc R 500 kpc from the center
of M87. The radial velocity distribution of these IGCs shows two peaks, one at
= 1023 km s associated with the Virgo main body, and another
at = 36 km s associated with the infalling structure. The
velocity dispersion of the IGCs in the Virgo main body is 314 km s, which is smoothly connected to the velocity dispersion
profile of M87 GCs, but much lower than that of dwarf galaxies in the same
survey field, 608 km s. The UCDs are more
centrally concentrated on massive galaxies, M87, M86, and M84. The radial
velocity dispersion of the UCD system is much smaller than that of dwarf
galaxies. Our results confirm the large-scale distribution of Virgo IGCs
indicated by previous photometric surveys. The color distribution of the
confirmed IGCs shows a bimodality similar to that of M87 GCs. This indicates
that most IGCs are stripped off from dwarf galaxies and some from massive
galaxies in the Virgo.Comment: 19 pages, 20 figures, 8 tables, accepted for publication in Ap
Synthesis of Bifunctional Poly(Vinyl Phosphonic Acid-co-glycidyl Metacrylate-co-divinyl Benzene) Cation-Exchange Resin and Its Indium Adsorption Properties from Indium Tin Oxide Solution
ABSTRACT Poly(vinyl phosphonic acid-co-glycidyl methacrylate-co-divinyl benzene) (PVGD) and PVGD containing an iminodiacetic acid group (IPVGD), which has indium ion selectivity, were synthesized by suspension polymerization, and their indium adsorption properties were investigated. The synthesized PVGD and IPVGD resins were characterized using Fourier transform infrared (FT-IR) spectroscopy, scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy (EDS) and mercury porosimetry. The cation-exchange capacity, the water uptake and the indium adsorption properties were investigated. The cation-exchange capacities of PVGD and IPVGD were 1.2 -4.5 meq/g and 2.5 -6.4 meq/g, respectively. The water uptakes were decreased with increasing contents of divinyl benzene (DVB). The water uptake values were 25% -40% and 20% -35%, respectively. The optimum adsorption of indium from a pure indium solution and an artificial indium tin oxide (ITO) solution by the PVGD and IPVGD ion-exchange resins were 2.3 and 3.5 meq/g, respectively. The indium adsorption capacities of IPVGD were higher than those of PVGD. The indium ion adsorption selectivity in the artificial ITO solution by PVGD and IPVGD was excellent, and other ions were adsorbed only slightly
Improving Neural Radiance Field using Near-Surface Sampling with Point Cloud Generation
Neural radiance field (NeRF) is an emerging view synthesis method that
samples points in a three-dimensional (3D) space and estimates their existence
and color probabilities. The disadvantage of NeRF is that it requires a long
training time since it samples many 3D points. In addition, if one samples
points from occluded regions or in the space where an object is unlikely to
exist, the rendering quality of NeRF can be degraded. These issues can be
solved by estimating the geometry of 3D scene. This paper proposes a
near-surface sampling framework to improve the rendering quality of NeRF. To
this end, the proposed method estimates the surface of a 3D object using depth
images of the training set and sampling is performed around there only. To
obtain depth information on a novel view, the paper proposes a 3D point cloud
generation method and a simple refining method for projected depth from a point
cloud. Experimental results show that the proposed near-surface sampling NeRF
framework can significantly improve the rendering quality, compared to the
original NeRF and a state-of-the-art depth-based NeRF method. In addition, one
can significantly accelerate the training time of a NeRF model with the
proposed near-surface sampling framework.Comment: 13 figures, 2 table
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