138 research outputs found
Joint Beamforming Design for RIS-Assisted Integrated Sensing and Communication Systems
Integrated sensing and communication (ISAC) has been envisioned as a
promising technology to tackle the spectrum congestion problem for future
networks. In this correspondence, we investigate to deploy a reconfigurable
intelligent surface (RIS) in an ISAC system for achieving better performance.
In particular, a multi-antenna base station (BS) simultaneously serves multiple
single-antenna users with the assistance of a RIS and detects potential
targets. The active beamforming of the BS and the passive beamforming of the
RIS are jointly optimized to maximize the achievable sum-rate of the
communication users while satisfying the constraint of beampattern similarity
for radar sensing, the restriction of the RIS, and the transmit power budget.
An efficient alternating algorithm based on the fractional programming (FP),
majorization-minimization (MM), and manifold optimization methods is developed
to convert the resulting non-convex optimization problem into two solvable
sub-problems and iteratively solve them. Simulation studies illustrate the
advancement of deploying RIS in ISAC systems and the effectiveness of the
proposed algorithm.Comment: Accepted by IEEE TV
An Efficient Dynamic Multi-Sources To Single-Destination (DMS-SD) Algorithm In Smart City Navigation Using Adjacent Matrix
Dijkstra's algorithm is one of the most popular classic path planning
algorithms, achieving optimal solutions across a wide range of challenging
tasks. However, it only calculates the shortest distance from one vertex to
another, which is hard to directly apply to the Dynamic Multi-Sources to
Single-Destination (DMS-SD) problem. This paper proposes a modified Dijkstra
algorithm to address the DMS-SD problem, where the destination can be
dynamically changed. Our method deploys the concept of Adjacent Matrix from
Floyd's algorithm and achieves the goal with mathematical calculations. We
formally show that all-pairs shortest distance information in Floyd's algorithm
is not required in our algorithm. Extensive experiments verify the scalability
and optimality of the proposed method.Comment: International Conference On Human-Centered Cognitive Systems (HCCS)
202
Integrated Sensing and Communications for IoT: Synergies with Key 6G Technology Enablers
The Internet of Things (IoT) and wireless generations have been evolving
simultaneously for the past few decades. Built upon wireless communication and
sensing technologies, IoT networks are usually evaluated based on metrics that
measure the device ability to sense information and effectively share it with
the network, which makes Integrated Sensing and Communication (ISAC) a pivotal
candidate for the sixth-generation (6G) IoT standards. This paper reveals
several innovative aspects of ISAC from an IoT perspective in 6G, empowering
various modern IoT use cases and key technology enablers. Moreover, we address
the challenges and future potential of ISAC-enabled IoT, including synergies
with Reconfigurable Intelligent Surfaces (RIS), Artificial Intelligence (AI),
and key updates of ISAC-IoT in 6G standardization. Furthermore, several
evolutionary concepts are introduced to open future research in 6G ISAC-IoT,
including the interplay with Non-Terrestrial Networks (NTN) and Orthogonal
Time-Frequency Space (OTFS) modulation.Comment: 7 pages, 6 figure
The antioxidant activity of polysaccharides from Armillaria gallica
The purpose of this study was to investigate the antioxidant activity of Armillaria gallica polysaccharides. It explored whether Armillaria gallica polysaccharides (AgP) could prevent HepG2 cells from H2O2-induced oxidative damage. The results demonstrated that HepG2 cells were significantly protected by AgP, and efficiently suppressed the production of reactive oxygen species (ROS) in HepG2 cells. Additionally, AgP significantly decreased the abnormal leakage of alanine aminotransferase (ALT) and lactate dehydrogenase (LDH) caused by H2O2, protecting cell membrane integrity. It was discovered that AgP was also found to regulate the activities of antioxidant enzymes, superoxide dismutase (SOD), catalase (CAT), and glutathione peroxidase (GSH-PX), while reducing malondialdehyde (MDA), thus protecting cells from oxidative damage. According to the flow cytometry analysis and measurement of caspase-3, caspase-8, and caspase-9 activities, AgP could modulate apoptosis-related proteins and attenuate ROS-mediated cell apoptosis
Real-time Monitoring for the Next Core-Collapse Supernova in JUNO
Core-collapse supernova (CCSN) is one of the most energetic astrophysical
events in the Universe. The early and prompt detection of neutrinos before
(pre-SN) and during the SN burst is a unique opportunity to realize the
multi-messenger observation of the CCSN events. In this work, we describe the
monitoring concept and present the sensitivity of the system to the pre-SN and
SN neutrinos at the Jiangmen Underground Neutrino Observatory (JUNO), which is
a 20 kton liquid scintillator detector under construction in South China. The
real-time monitoring system is designed with both the prompt monitors on the
electronic board and online monitors at the data acquisition stage, in order to
ensure both the alert speed and alert coverage of progenitor stars. By assuming
a false alert rate of 1 per year, this monitoring system can be sensitive to
the pre-SN neutrinos up to the distance of about 1.6 (0.9) kpc and SN neutrinos
up to about 370 (360) kpc for a progenitor mass of 30 for the case
of normal (inverted) mass ordering. The pointing ability of the CCSN is
evaluated by using the accumulated event anisotropy of the inverse beta decay
interactions from pre-SN or SN neutrinos, which, along with the early alert,
can play important roles for the followup multi-messenger observations of the
next Galactic or nearby extragalactic CCSN.Comment: 24 pages, 9 figure
Potential of Core-Collapse Supernova Neutrino Detection at JUNO
JUNO is an underground neutrino observatory under construction in Jiangmen, China. It uses 20kton liquid scintillator as target, which enables it to detect supernova burst neutrinos of a large statistics for the next galactic core-collapse supernova (CCSN) and also pre-supernova neutrinos from the nearby CCSN progenitors. All flavors of supernova burst neutrinos can be detected by JUNO via several interaction channels, including inverse beta decay, elastic scattering on electron and proton, interactions on C12 nuclei, etc. This retains the possibility for JUNO to reconstruct the energy spectra of supernova burst neutrinos of all flavors. The real time monitoring systems based on FPGA and DAQ are under development in JUNO, which allow prompt alert and trigger-less data acquisition of CCSN events. The alert performances of both monitoring systems have been thoroughly studied using simulations. Moreover, once a CCSN is tagged, the system can give fast characterizations, such as directionality and light curve
Detection of the Diffuse Supernova Neutrino Background with JUNO
As an underground multi-purpose neutrino detector with 20 kton liquid scintillator, Jiangmen Underground Neutrino Observatory (JUNO) is competitive with and complementary to the water-Cherenkov detectors on the search for the diffuse supernova neutrino background (DSNB). Typical supernova models predict 2-4 events per year within the optimal observation window in the JUNO detector. The dominant background is from the neutral-current (NC) interaction of atmospheric neutrinos with 12C nuclei, which surpasses the DSNB by more than one order of magnitude. We evaluated the systematic uncertainty of NC background from the spread of a variety of data-driven models and further developed a method to determine NC background within 15\% with {\it{in}} {\it{situ}} measurements after ten years of running. Besides, the NC-like backgrounds can be effectively suppressed by the intrinsic pulse-shape discrimination (PSD) capabilities of liquid scintillators. In this talk, I will present in detail the improvements on NC background uncertainty evaluation, PSD discriminator development, and finally, the potential of DSNB sensitivity in JUNO
Recent Advances in the Biosynthesis of Natural Sugar Substitutes in Yeast
Natural sugar substitutes are safe, stable, and nearly calorie-free. Thus, they are gradually replacing the traditional high-calorie and artificial sweeteners in the food industry. Currently, the majority of natural sugar substitutes are extracted from plants, which often requires high levels of energy and causes environmental pollution. Recently, biosynthesis via engineered microbial cell factories has emerged as a green alternative for producing natural sugar substitutes. In this review, recent advances in the biosynthesis of natural sugar substitutes in yeasts are summarized. The metabolic engineering approaches reported for the biosynthesis of oligosaccharides, sugar alcohols, glycosides, and rare monosaccharides in various yeast strains are described. Meanwhile, some unresolved challenges in the bioproduction of natural sugar substitutes in yeast are discussed to offer guidance for future engineering
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