2,851 research outputs found
Decoherence and Landauer's Principle in Qubit-Cavity Quantum-Field-Theory Interaction
We consider quantum decoherence and Landauer's principle in qubit-cavity
quantum field theory (QFT) interaction, treating the qubit as the system and
cavity QFT as the environment. In particular, we investigate the changes that
occur in the system with a pure initial state and environment during the
decoherence process, with or without energy dissipation, and compare the
results with the case in which the initial state of the system is a mixed state
and thus decoherence is absent. When we choose an interaction Hamiltonian such
that the energy and coherence of the system change simultaneously, the
population change of the system and the energy change are the same when the
initial state is mixed. However, the decoherence terms increase the von Neumann
entropy of the system. On the other hand, if the interaction Hamiltonian does
not change the energy of the system, there is only the decoherence effect. The
environment will be a distribution in the basis of the displaced number state
and always increases the energy. Landauer's principle is satisfied in both
cases.Comment: 8 pages, 4 figure
Structural and molecular basis of the assembly of the TRPP2/PKD1 complex
Mutations in PKD1 and TRPP2 account for nearly all cases of autosomal dominant polycystic kidney disease (ADPKD). These 2 proteins form a receptor/ion channel complex on the cell surface. Using a combination of biochemistry, crystallography, and a single-molecule method to determine the subunit composition of proteins in the plasma membrane of live cells, we find that this complex contains 3 TRPP2 and 1 PKD1. A newly identified coiled-coil domain in the C terminus of TRPP2 is critical for the formation of this complex. This coiled-coil domain forms a homotrimer, in both solution and crystal structure, and binds to a single coiled-coil domain in the C terminus of PKD1. Mutations that disrupt the TRPP2 coiled-coil domain trimer abolish the assembly of both the full-length TRPP2 trimer and the TRPP2/PKD1 complex and diminish the surface expression of both proteins. These results have significant implications for the assembly, regulation, and function of the TRPP2/PKD1 complex and the pathogenic mechanism of some ADPKD-producing mutations
A Parallel Thrombolysis Protocol with Nurse Practitioners As Coordinators Minimized Door-to-Needle Time for Acute Ischemic Stroke
Introduction. Quick thrombolysis after stroke improved clinical outcomes. The study objective was to shorten door-to-needle time for thrombolysis. Methods. After identifying the sources of in-hospital delays, we developed a protocol with a parallel algorithm and recruited nurse practitioners into the acute stroke team. We applied the new protocol on stroke patients from October 2009 to September 2010. Patients from the previous two years were used for comparison. Results. For ischemic stroke patients within 3 hours of onset, the median time from arrival to computed tomography scanning was reduced from 29 to 20 minutes (P < 0.001) and the median time from arrival to neurology evaluation decreased from 61 to 43 minutes (P < 0.001). For those patients who received thrombolysis, the median door-to-needle time was shortened from 68.5 to 58 minutes (P < 0.05). Conclusions. The parallel thrombolysis protocol successfully improved the median door-to-needle time to below the guideline-recommended 60 minutes
Processing multiple image streams for real-time monitoring of parking lots
We present a system to detect parked vehicles in a typical parking complex using multiple streams of images captured through IP connected devices. Compared to traditional object detection techniques and machine learning methods, our approach is significantly faster in detection speed in the presence of multiple image streams. It is also capable of comparable accuracy when put to test against existing methods. And this is achieved without the need to train the system that machine learning methods require. Our approach uses a combination of psychological insights obtained from human detection and an algorithm replicating the outcomes of a SVM learner but without the noise that compromises accuracy in the normal learning process. Performance enhancements are made on the algorithm so that it operates well in the context of multiple image streams. The result is faster detection with comparable accuracy. Our experiments on images captured from a local test site shows very promising results for an implementation that is not only effective and low cost but also opens doors to new parking applications when combined with other technologies.<br /
Regular Black Hole Interior Spacetime Supported by Three-Form Field
In this paper, we show that a minimally coupled 3-form endowed with a proper
potential can support a regular black hole interior. By choosing an appropriate
form for the metric function representing the radius of the 2-sphere, we solve
for the 3-form field and its potential. Using the obtained solution, we
construct an interior black hole spacetime which is everywhere regular. The
singularity is replaced with a Nariai-type spacetime, whose topology is
, in which the radius of the 2-sphere is
constant. So long as the interior continues to expand indefinitely, the
geometry becomes essentially compactified. The 2-dimensional de Sitter geometry
appears despite the negative potential of the 3-form field. Such a dynamical
compactification could shed some light on the origin of de Sitter geometry of
our Universe, exacerbated by the Swampland conjecture. In addition, we show
that the spacetime is geodesically complete. The geometry is singularity-free
due to the violation of the null energy condition.Comment: 13 pages, 6 figures. Updated to match the published versio
Client-side Gradient Inversion Against Federated Learning from Poisoning
Federated Learning (FL) enables distributed participants (e.g., mobile
devices) to train a global model without sharing data directly to a central
server. Recent studies have revealed that FL is vulnerable to gradient
inversion attack (GIA), which aims to reconstruct the original training samples
and poses high risk against the privacy of clients in FL. However, most
existing GIAs necessitate control over the server and rely on strong prior
knowledge including batch normalization and data distribution information. In
this work, we propose Client-side poisoning Gradient Inversion (CGI), which is
a novel attack method that can be launched from clients. For the first time, we
show the feasibility of a client-side adversary with limited knowledge being
able to recover the training samples from the aggregated global model. We take
a distinct approach in which the adversary utilizes a malicious model that
amplifies the loss of a specific targeted class of interest. When honest
clients employ the poisoned global model, the gradients of samples belonging to
the targeted class are magnified, making them the dominant factor in the
aggregated update. This enables the adversary to effectively reconstruct the
private input belonging to other clients using the aggregated update. In
addition, our CGI also features its ability to remain stealthy against
Byzantine-robust aggregation rules (AGRs). By optimizing malicious updates and
blending benign updates with a malicious replacement vector, our method remains
undetected by these defense mechanisms. To evaluate the performance of CGI, we
conduct experiments on various benchmark datasets, considering representative
Byzantine-robust AGRs, and exploring diverse FL settings with different levels
of adversary knowledge about the data. Our results demonstrate that CGI
consistently and successfully extracts training input in all tested scenarios
The ‘Singapore Fever’ in China: policy mobility and mutation
The ‘Singapore Model’ has constituted the only second explicit attempt by the Communist Party of China (CPC) to learn from a foreign country following Mao Zedong’s pledge to contour ‘China’s tomorrow’ on the Soviet Union experience during the early 1950s. This paper critically evaluates policy transfers from Singapore to China in the post-Mao era. It re-examines how this Sino-Singaporean regulatory engagement came about historically following Deng Xiaoping’s visit to Singapore in 1978, and offers a careful re-reading of the degree to which actual policy borrowing by China could transcend different state ideologies, abstract ideas and subjective attitudes. Particular focus is placed on the effects of CPC cadre training in Singapore universities and policy mutation within two government-to-government projects, namely the Suzhou Industrial Park and the Tianjin Eco-City. The paper concludes that the ‘Singapore Model’, as applied in post-Mao China, casts institutional reforms as an open-ended process of policy experimentation and adaptation that is fraught with tension and resistance
Kalman Filter Models for the Prediction of Individualised Thermal Work Strain
It is important to monitor and assess the physiological strain of individuals working in hot environments to avoid heat illness and performance degradation. The body core temperature (Tc) is a reliable indicator of thermal work strain. However, measuring Tc is invasive and often inconvenient and impractical for real-time monitoring of workers in high heat strain environments. Seeking a better solution, the main aim of the present study was to investigate the Kalman filter method to enable the estimation of heat strain from non-invasive measurements (heart rate (HR) and chest skin temperature (ST)) obtained ‘online’ via wearable body sensors. In particular, we developed two Kalman filter models. First, an extended Kalman filter (EFK) was implemented in a cubic state space modelling framework (HR versus Tc) with a stage-wise, autoregressive exogenous model (incorporating HR and ST) as the time update model. Under the second model, the online Kalman filter (OFK) approach builds up the time update equation depending only on the initial value of Tc and the latest value of the exogenous variables. Both models were trained and validated using data from laboratory- and outfield-based heat strain profiling studies in which subjects performed a high intensity military foot march. While both the EKF and OKF models provided satisfactory estimates of Tc, the results showed an overall superior performance of the OKF model (overall root mean square error, RMSE = 0.31°C) compared to the EKF model (RMSE = 0.45°C)
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