1,142 research outputs found
Collective quantum phase slips in multiple nanowire junctions
Realization of robust coherent quantum phase slips represents a significant
experimental challenge. Here we propose a new design consisting of multiple
nanowire junctions to realize a phase-slip flux qubit. It admits good
tunability provided by gate voltages applied on superconducting islands
separating nanowire junctions. In addition, the gates and junctions can be
identical or distinct to each other leading to symmetric and asymmetric setups.
We find that the asymmetry can improve the performance of the proposed device,
compared with the symmetric case. In particular, it can enhance the effective
rate of collective quantum phase slips. Furthermore, we demonstrate how to
couple two such devices via a mutual inductance. This is potentially useful for
quantum gate operations. Our investigation on how symmetry in multiple nanowire
junctions affects the device performance should be useful for the application
of phase-slip flux qubits in quantum information processing and quantum
metrology.Comment: 12 pages, 6 figure
Security proof of differential phase shift quantum key distribution in the noiseless case
Differential phase shift quantum key distribution systems have a high
potential for achieving high speed key generation. However, its unconditional
security proof is still missing, even though it has been proposed for many
years. Here, we prove its security against collective attacks with a weak
coherent light source in the noiseless case (i.e. no bit error). The only
assumptions are that quantum theory is correct, the devices are perfect and
trusted and the key size is infinite. Our proof works on threshold detectors.
We compute the lower bound of the secret key generation rate using the
information-theoretical security proof method. Our final result shows that the
lower bound of the secret key generation rate per pulse is linearly
proportional to the channel transmission probability if Bob's detection counts
obey the binomial distribution.Comment: Published version, 13 pages, 4 figures, minor changes, references
added, acknowledgement adde
Preventing Unauthorized AI Over-Analysis by Medical Image Adversarial Watermarking
The advancement of deep learning has facilitated the integration of
Artificial Intelligence (AI) into clinical practices, particularly in
computer-aided diagnosis. Given the pivotal role of medical images in various
diagnostic procedures, it becomes imperative to ensure the responsible and
secure utilization of AI techniques. However, the unauthorized utilization of
AI for image analysis raises significant concerns regarding patient privacy and
potential infringement on the proprietary rights of data custodians.
Consequently, the development of pragmatic and cost-effective strategies that
safeguard patient privacy and uphold medical image copyrights emerges as a
critical necessity. In direct response to this pressing demand, we present a
pioneering solution named Medical Image Adversarial watermarking (MIAD-MARK).
Our approach introduces watermarks that strategically mislead unauthorized AI
diagnostic models, inducing erroneous predictions without compromising the
integrity of the visual content. Importantly, our method integrates an
authorization protocol tailored for legitimate users, enabling the removal of
the MIAD-MARK through encryption-generated keys. Through extensive experiments,
we validate the efficacy of MIAD-MARK across three prominent medical image
datasets. The empirical outcomes demonstrate the substantial impact of our
approach, notably reducing the accuracy of standard AI diagnostic models to a
mere 8.57% under white box conditions and 45.83% in the more challenging black
box scenario. Additionally, our solution effectively mitigates unauthorized
exploitation of medical images even in the presence of sophisticated watermark
removal networks. Notably, those AI diagnosis networks exhibit a meager average
accuracy of 38.59% when applied to images protected by MIAD-MARK, underscoring
the robustness of our safeguarding mechanism
Pre-classification module for an all-season image retrieval system
Author name used in this publication: Zheru ChiAuthor name used in this publication: Dagan FengCentre for Multimedia Signal Processing, Department of Electronic and Information EngineeringRefereed conference paper2007-2008 > Academic research: refereed > Refereed conference paperVersion of RecordPublishe
High accuracy microwave frequency measurement based on single-drive dual-parallel Mach-Zehnder modulator
A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented 10−3 relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications. A novel approach for broadband microwave frequency measurement by employing a single-drive dual-parallel Mach-Zehnder modulator is proposed and experimentally demonstrated. Based on bias manipulations of the modulator, conventional frequency-to-power mapping technique is developed by performing a two-stage frequency measurement cooperating with digital signal processing. In the experiment, 10GHz measurement range is guaranteed and the average uncertainty of estimated microwave frequency is 5.4MHz, which verifies the measurement accuracy is significantly improved by achieving an unprecedented 10−3 relative error. This high accuracy frequency measurement technique is a promising candidate for high-speed electronic warfare and defense applications
NRAV, a Long Noncoding RNA, Modulates Antiviral Responses through Suppression of Interferon-Stimulated Gene Transcription
SummaryLong noncoding RNAs (lncRNAs) modulate various biological processes, but their role in host antiviral responses is largely unknown. Here we identify a lncRNA as a key regulator of antiviral innate immunity. Following from the observation that a lncRNA that we call negative regulator of antiviral response (NRAV) was dramatically downregulated during infection with several viruses, we ectopically expressed NRAV in human cells or transgenic mice and found that it significantly promotes influenza A virus (IAV) replication and virulence. Conversely, silencing NRAV suppressed IAV replication and virus production, suggesting that reduction of NRAV is part of the host antiviral innate immune response to virus infection. NRAV negatively regulates the initial transcription of multiple critical interferon-stimulated genes (ISGs), including IFITM3 and MxA, by affecting histone modification of these genes. Our results provide evidence for a lncRNA in modulating the antiviral interferon response
Eff ect of a comprehensive programme to provide universal access to care for sputum-smear-positive multidrugresistant tuberculosis in China: a before-and-after study
Background China has a quarter of all patients with multidrug-resistant tuberculosis (MDRTB) worldwide, but less
than 5% are in quality treatment programmes. In a before-and-after study we aimed to assess the eff ect of a
comprehensive programme to provide universal access to diagnosis, treatment, and follow-up for MDRTB in
four Chinese cities (population 18 million).
Methods We designated city-level hospitals in each city to diagnose and treat MDRTB. All patients with smear-positive
pulmonary tuberculosis diagnosed in Center for Disease Control (CDC) clinics and hospitals were tested for MDRTB
with molecular and conventional drug susceptibility tests. Patients were treated with a 24 month treatment package
for MDRTB based on WHO guidelines. Outpatients were referred to the CDC for directly observed therapy.
We capped total treatment package cost at US796 to $174), reducing the ratio of patients’ expenses
to annual household income from 17·6% to 3·5% (p<0·0001 for all comparisons between baseline and programme
periods). However, 36 (15%) patients did not start or had to discontinue treatment in the programme period because
of fi nancial diffi culties.
Interpretation This comprehensive programme substantially increased access to diagnosis, quality treatment, and
aff ordable treatment for MDRTB. The programme could help China to achieve universal access to MDRTB care but
greater fi nancial risk protection for patients is needed
Simultaneous compression of the passively mode-locked pulsewidth and pulse train
Simultaneous compression of the passively mode-locked pulse width and pulse train have been achieved by using a plano-convex unstable resonator hybrided by a nonlinear Sagnac ring interferometer. The greater than 30 mJ single pulse energy of a lone oscillator and less than or equal to 10 ps pulsewidth have been obtained. Using this system, the LAGEOS and ETALON satellites' laser ranging have been performed successfully
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