1,377 research outputs found
Bandwidth allocation and pricing problem for a duopoly market
This research discusses the Internet service provider (ISP) bandwidth allocation and pricing problems for a duopoly bandwidth market with two competitive ISPs. According to the contracts between Internet subscribers and ISPs, Internet subscribers can enjoy their services up to their contracted bandwidth limits. However, in reality, many subscribers may experience the facts that their on-line requests are denied or their connection speeds are far below their contracted speed limits. One of the reasons is that ISPs accept too many subscribers as their subscribers. To avoid this problem, ISPs can set limits for their subscribers to enhance their service qualities. This paper develops constrained nonlinear programming to deal with this problem for two competitive ISPs. The condition for reaching the equilibrium between the two competitive firms is derived. The market equilibrium price and bandwidth resource allocations are derived as closed form solutions
Cavity locking with spatial modulation of optical phase front for laser stabilization
We study optical cavity locking for laser stabilization through spatial
modulation of the phase front of a light beam. A theoretical description of the
underlying principle is developed for this method and special attention is paid
to residual amplitude modulation (RAM) caused by experimental imperfections,
especially the manufacture errors of the spatial phase modulator. The studied
locking method owns the common advantages of the Pound-Drever-Hall method and
the tilt-locking one, and it can provide a more artful way to eliminate RAM
noise in phase modulation for the ultimate stability of lasers. In situations
where cost and portability are a practical issue, the studied method allows one
to realize compact laser stabilization systems locked to
Fabry-P\acute{\mbox{e}}rot cavities without use of expensive bulky devices,
such as signal generators and electro-optic modulators.Comment: 3 figure
Accurate Prediction of Antibody Function and Structure Using Bio-Inspired Antibody Language Model
In recent decades, antibodies have emerged as indispensable therapeutics for
combating diseases, particularly viral infections. However, their development
has been hindered by limited structural information and labor-intensive
engineering processes. Fortunately, significant advancements in deep learning
methods have facilitated the precise prediction of protein structure and
function by leveraging co-evolution information from homologous proteins.
Despite these advances, predicting the conformation of antibodies remains
challenging due to their unique evolution and the high flexibility of their
antigen-binding regions. Here, to address this challenge, we present the
Bio-inspired Antibody Language Model (BALM). This model is trained on a vast
dataset comprising 336 million 40% non-redundant unlabeled antibody sequences,
capturing both unique and conserved properties specific to antibodies. Notably,
BALM showcases exceptional performance across four antigen-binding prediction
tasks. Moreover, we introduce BALMFold, an end-to-end method derived from BALM,
capable of swiftly predicting full atomic antibody structures from individual
sequences. Remarkably, BALMFold outperforms those well-established methods like
AlphaFold2, IgFold, ESMFold, and OmegaFold in the antibody benchmark,
demonstrating significant potential to advance innovative engineering and
streamline therapeutic antibody development by reducing the need for
unnecessary trials
High speed self-testing quantum random number generation without detection loophole
Quantum mechanics provides means of generating genuine randomness that is
impossible with deterministic classical processes. Remarkably, the
unpredictability of randomness can be certified in a self-testing manner that
is independent of implementation devices. Here, we present an experimental
demonstration of self-testing quantum random number generation based on an
detection-loophole free Bell test with entangled photons. In the randomness
analysis, without the assumption of independent identical distribution, we
consider the worst case scenario that the adversary launches the most powerful
attacks against quantum adversary. After considering statistical fluctuations
and applying an 80 Gb 45.6 Mb Toeplitz matrix hashing, we achieve a
final random bit rate of 114 bits/s, with a failure probability less than
. Such self-testing random number generators mark a critical step
towards realistic applications in cryptography and fundamental physics tests.Comment: 34 pages, 10 figure
Higgs-Boson Production Associated with a Single Bottom Quark in Supersymmetric QCD
Due to the enhancement of the couplings between Higgs boson and bottom quarks
in the minimal sypersymmetric standard model (MSSM), the cross section of the
process pp(p\bar{p}) \to h^0b(h^0\bar{b})+X at hadron colliders can be
considerably enhanced. We investigated the production of Higgs boson associated
with a single high-p_T bottom quark via subprocess bg(\bar{b}g) \to
h^0b(h^0\bar{b}) at hadron colliders including the next-to-leading order (NLO)
QCD corrections in MSSM. We find that the NLO QCD correction in the MSSM
reaches 50%-70% at the LHC and 60%-85% at the Fermilab Tevatron in our chosen
parameter space.Comment: accepted by Phys. Rev.
High-speed measurement-device-independent quantum key distribution with integrated silicon photonics
Measurement-device-independent quantum key distribution (MDI-QKD) removes all
detector side channels and enables secure QKD with an untrusted relay. It is
suitable for building a star-type quantum access network, where the complicated
and expensive measurement devices are placed in the central untrusted relay and
each user requires only a low-cost transmitter, such as an integrated photonic
chip. Here, we experimentally demonstrate a 1.25 GHz silicon photonic
chip-based MDI-QKD system using polarization encoding. The photonic chip
transmitters integrate the necessary encoding components for a standard QKD
source. We implement random modulations of polarization states and decoy
intensities, and demonstrate a finite-key secret rate of 31 bps over 36 dB
channel loss (or 180 km standard fiber). This key rate is higher than
state-of-the-art MDI-QKD experiments. The results show that silicon photonic
chip-based MDI-QKD, benefiting from miniaturization, low-cost manufacture and
compatibility with CMOS microelectronics, is a promising solution for future
quantum secure networks.Comment: 30 pages, 12 figure
Pseudoscalar Higgs boson production associated with a single bottom quark at hadron colliders
We compute the complete next-to-leading order (NLO) SUSY-QCD corrections for
the associated production of a pseudoscalar Higgs boson with a bottom quark via
bottom-gluon fusion at the CERN Large Hadron Collider (LHC) and the Fermilab
Tevatron. We find that the NLO QCD correction in the MSSM reaches
at the LHC and at the Tevatron in our chosen parameter space
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