1,459 research outputs found
A Trust Model Based on Service Classification in Mobile Services
Internet of Things (IoT) and B3G/4G communication are promoting the pervasive
mobile services with its advanced features. However, security problems are also
baffled the development. This paper proposes a trust model to protect the
user's security. The billing or trust operator works as an agent to provide a
trust authentication for all the service providers. The services are classified
by sensitive value calculation. With the value, the user's trustiness for
corresponding service can be obtained. For decision, three trust regions are
divided, which is referred to three ranks: high, medium and low. The trust
region tells the customer, with his calculated trust value, which rank he has
got and which authentication methods should be used for access. Authentication
history and penalty are also involved with reasons.Comment: IEEE/ACM Internet of Things Symposium (IOTS), in conjunction with
GreenCom 2010, IEEE, Hangzhou, China, December 18-20, 201
Entanglement for a Bimodal Cavity Field Interacting with a Two-Level Atom
Negativity has been adopted to investigate the entanglement in a system
composed of a two-level atom and a two-mode cavity field. Effects of Kerr-like
medium and the number of photon inside the cavity on the entanglement are
studied. Our results show that atomic initial state must be superposed, so that
the two cavity field modes can be entangled. Moreover, we also conclude that
the number of photon in the two cavity mode should be equal. The interaction
between modes, namely, the Kerr effect, has a significant negative
contribution. Note that the atom frequency and the cavity frequency have an
indistinguishable effect, so a corresponding approximation has been made in
this article. These results may be useful for quantum information in optics
systems.Comment: Accepted by Commun. Theor. Phy
Use of low-dose computed tomography to assess pulmonary tuberculosis among healthcare workers in a tuberculosis hospital
BACKGROUND: According to the World Health Organization, China is one of 22 countries with serious tuberculosis (TB) infections and one of the 27 countries with serious multidrug-resistant TB strains. Despite the decline of tuberculosis in the overall population, healthcare workers (HCWs) are still at a high risk of infection. Compared with high-income countries, the TB prevalence among HCWs is higher in low- and middle-income countries. Low-dose computed tomography (LDCT) is becoming more popular due to its superior sensitivity and lower radiation dose. However, there have been no reports about active pulmonary tuberculosis (PTB) among HCWs as assessed with LDCT. The purposes of this study were to examine PTB statuses in HCWs in hospitals specializing in TB treatment and explore the significance of the application of LDCT to these workers. METHODS: This study retrospectively analysed the physical examination data of healthcare workers in the Beijing Chest Hospital from September 2012 to December 2015. Low-dose lung CT examinations were performed in all cases. The comparisons between active and inactive PTB according to the CT findings were made using the Pearson chi-square test or the Fisher’s exact test. Comparisons between the incidences of active PTB in high-risk areas and non-high-risk areas were performed using the Pearson chi-square test. Analyses of active PTB were performed according to different ages, numbers of years on the job, and the risks of the working areas. Active PTB as diagnosed by the LDCT examinations alone was compared with the final comprehensive diagnoses, and the sensitivity and positive predictive value were calculated. RESULTS: A total of 1 012 participants were included in this study. During the 4-year period of medical examinations, active PTB was found in 19 cases, and inactive PTB was found in 109 cases. The prevalence of active PTB in the participants was 1.24%, 0.67%, 0.81%, and 0.53% for years 2012 to 2015. The corresponding incidences of active PTB among the tuberculosis hospital participants were 0.86%, 0.41%, 0.54%, and 0.26%. Most HCWs with active TB (78.9%, 15/19) worked in the high-risk areas of the hospital. There was a significant difference in the incidences of active PTB between the HCWs who worked in the high-risk and non-high-risk areas (odds ratio [OR], 14.415; 95% confidence interval (CI): 4.733 – 43.896). Comparisons of the CT signs between the active and inactive groups via chi-square tests revealed that the tree-in-bud, cavity, fibrous shadow, and calcification signs exhibited significant differences (P = 0.000, 0.021, 0.001, and 0.024, respectively). Tree-in-bud and cavity opacities suggest active pulmonary tuberculosis, whereas fibrous shadow and calcification opacities are the main features of inactive pulmonary tuberculosis. Comparison with the final comprehensive diagnoses revealed that the sensitivity and positive predictive value of the diagnoses of active PTB based on LDCT alone were 100% and 86.4%, respectively. CONCLUSIONS: Healthcare workers in tuberculosis hospitals are a high-risk group for active PTB. Yearly LDCT examinations of such high-risk groups are feasible and necessary. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1186/s40249-017-0274-6) contains supplementary material, which is available to authorized users
Berry Phase in a Two-atom Jaynes-Cummings Model with Kerr Medium
he Jaynes-Cummings model (JCM) is an very important model for describing
interaction between quantized electromagnetic fields and atoms in cavity
quantum electrodynamics (QED). This model is generalized in many different
direction since it predicts many novel quantum effects that can be verified by
modern physics experimental technologies. In this paper, the Berry phase and
entropy of the ground state for arbitrary photon number of a two-atom
Jaynes-Cummings model with Kerr like medium are investigated. It is found that
there are some correspondence between their images, especially the existence of
a curve in the plane along which the energy, Berry phase
and entropy all reach their special values. So it is available for detecting
entanglement by applying Berry phase.Comment: accepted by physica script
Unsupervised Anomaly Detection via Variational Auto-Encoder for Seasonal KPIs in Web Applications
To ensure undisrupted business, large Internet companies need to closely
monitor various KPIs (e.g., Page Views, number of online users, and number of
orders) of its Web applications, to accurately detect anomalies and trigger
timely troubleshooting/mitigation. However, anomaly detection for these
seasonal KPIs with various patterns and data quality has been a great
challenge, especially without labels. In this paper, we proposed Donut, an
unsupervised anomaly detection algorithm based on VAE. Thanks to a few of our
key techniques, Donut greatly outperforms a state-of-arts supervised ensemble
approach and a baseline VAE approach, and its best F-scores range from 0.75 to
0.9 for the studied KPIs from a top global Internet company. We come up with a
novel KDE interpretation of reconstruction for Donut, making it the first
VAE-based anomaly detection algorithm with solid theoretical explanation.Comment: 12 pages (including references), 17 figures, submitted to WWW 2018:
The 2018 Web Conference, April 23--27, 2018, Lyon, France. The contents
discarded from the conference version due to the 9-page limitation are also
included in this versio
Cardiac Sca-1+ cells are not intrinsic stem cells for myocardial development, renewal and repair
Background:
For over a decade, Sca-1+ cells within the mouse heart have been widely recognized as a stem cell population with multipotency that can give rise to cardiomyocytes, endothelial cells and smooth muscle cells in vitro and after cardiac grafting. However, the developmental origin and authentic nature of these cells remain elusive.
Methods:
Here, we used a series of high-fidelity genetic mouse models to characterize the identity and regenerative potential of cardiac resident Sca-1+ cells.
Results:
With these novel genetic mouse models, we found that Sca-1 does not label cardiac precursor cells during early embryonic heart formation. Postnatal cardiac resident Sca-1+ cells are in fact a pure endothelial cell population. They retain endothelial properties and exhibit minimal cardiomyogenic potential during development, normal aging and upon ischemic injury.
Conclusions:
Our study provides definitive insights into the nature of cardiac resident Sca-1+ cells. The observations challenge the current dogma that cardiac resident Sca-1+ cells are intrinsic stem cells for myocardial development, renewal and repair and suggest that the mechanisms of transplanted Sca-1+ cells in heart repair need to be reassessed
Bis[2-(1,3-benzothiaÂzol-2-ylsulfanÂyl)ethÂyl] ether
The complete molecule of title compound, C18H16N2OS4, is generated by crystallographic twofold symmetry, with the O atom lying on the rotation axis. The dihedral angle between the ring systems is 80.91 (2)°. In the crystal, adjacent molÂecules are connected through π–π stacking interÂactions [centroid–centroid distance = 3.882 (2) Å], forming a three-dimensional network
- …