2,766 research outputs found
Electromagnetic counterparts of high-frequency gravitational waves in a rotating laboratory frame system and their detection
We consider the perturbative photon flows (PPFs, i.e., electromagnetic (EM)
counterparts) generated by the EM resonance response to high-frequency
gravitational waves (HFGWs) with additional polarization states in a rotating
laboratory frame system. It is found that when the propagating direction of the
HFGWs and the symmetrical axis of the laboratory frame system are the same, the
PPFs have the maximum value. In this case, using the rotation (the rotation of
azimuth ) of the EM detection system, all six possible polarization
states of the HFGWs can be separated and displayed. For the current
experimental conditions, it is quite prospective to detect the PPFs generated
by the HFGWs predicted in the braneworld models, the primordial black hole
theories and the interaction mechanism between astrophysical plasma and intense
EM radiation, etc., due to the large amplitudes (or high spectral densities)
and spectral characteristics of these HFGWs. Detecting the primordial HFGWs
from inflation faces great challenges at present, but it is not impossible.Comment: 29 pages, 8 figures, 1 table; corrected some minor typos; added
reference
Neural Network Based Edge Detection for Automated Medical Diagnosis
Edge detection is an important but rather difficult task in image processing and analysis. In this research, artificial neural networks are employed for edge detection based on its adaptive learning and nonlinear mapping properties. Fuzzy sets are introduced during the training phase to improve the generalization ability of neural networks. The application of the proposed neural network approach to the edge detection of medical images for automated bladder cancer diagnosis is also investigated. Successful computer simulation results are obtained
Diagnostic value of two dimensional shear wave elastography combined with texture analysis in early liver fibrosis.
BACKGROUND: Staging diagnosis of liver fibrosis is a prerequisite for timely diagnosis and therapy in patients with chronic hepatitis B. In recent years, ultrasound elastography has become an important method for clinical noninvasive assessment of liver fibrosis stage, but its diagnostic value for early liver fibrosis still needs to be further improved. In this study, the texture analysis was carried out on the basis of two dimensional shear wave elastography (2D-SWE), and the feasibility of 2D-SWE plus texture analysis in the diagnosis of early liver fibrosis was discussed.
AIM: To assess the diagnostic value of 2D-SWE combined with textural analysis in liver fibrosis staging.
METHODS: This study recruited 46 patients with chronic hepatitis B. Patients underwent 2D-SWE and texture analysis; Young\u27s modulus values and textural patterns were obtained, respectively. Textural pattern was analyzed with regard to contrast, correlation, angular second moment (ASM), and homogeneity. Pathological results of biopsy specimens were the gold standard; comparison and assessment of the diagnosis efficiency were conducted for 2D-SWE, texture analysis and their combination.
RESULTS: 2D-SWE displayed diagnosis efficiency in early fibrosis, significant fibrosis, severe fibrosis, and early cirrhosis (AUC \u3e 0.7, P \u3c 0.05) with respective AUC values of 0.823 (0.678-0.921), 0.808 (0.662-0.911), 0.920 (0.798-0.980), and 0.855 (0.716-0.943). Contrast and homogeneity displayed independent diagnosis efficiency in liver fibrosis stage (AUC \u3e 0.7, P \u3c 0.05), whereas correlation and ASM showed limited values. AUC of contrast and homogeneity were respectively 0.906 (0.779-0.973), 0.835 (0.693-0.930), 0.807 (0.660-0.910) and 0.925 (0.805-0.983), 0.789 (0.639-0.897), 0.736 (0.582-0.858), 0.705 (0.549-0.883) and 0.798 (0.650-0.904) in four liver fibrosis stages, which exhibited equivalence to 2D-SWE in diagnostic efficiency (P \u3e 0.05). Combined diagnosis (PRE) displayed diagnostic efficiency (AUC \u3e 0.7, P \u3c 0.01) for all fibrosis stages with respective AUC of 0.952 (0.841-0.994), 0.896 (0.766-0.967), 0.978 (0.881-0.999), 0.947 (0.835-0.992). The combined diagnosis showed higher diagnosis efficiency over 2D-SWE in early liver fibrosis (P \u3c 0.05), whereas no significant differences were observed in other comparisons (P \u3e 0.05).
CONCLUSION: Texture analysis was capable of diagnosing liver fibrosis stage, combined diagnosis had obvious advantages in early liver fibrosis, liver fibrosis stage might be related to the hepatic tissue hardness distribution
Heat statistics in the relaxation process of the Edwards-Wilkinson elastic manifold
The stochastic thermodynamics of systems with a few degrees of freedom has
been studied extensively so far. We would like to extend the study to systems
with more degrees of freedom and even further-continuous fields with infinite
degrees of freedom. The simplest case for a continuous stochastic field is the
Edwards-Wilkinson elastic manifold. It is an exactly solvable model of which
the heat statistics in the relaxation process can be calculated analytically.
The cumulants require a cutoff spacing to avoid ultra-violet divergence. The
scaling behavior of the heat cumulants with time and the system size as well as
the large deviation rate function of the heat statistics in the large size
limit is obtained
The synthesis and characterization of 1111-type diluted magnetic semiconductors (La1-xSrx)(Zn1-xTMx)AsO (TM = Mn, Fe, Co)
The doping effect of Sr and transition metals Mn, Fe, Co into the direct-gap
semiconductor LaZnAsO has been investigated. Our results indicate that the
single phase ZrCuSiAs-type tetragonal crystal structure is preserved in
(La1-xSrx)(Zn1-xTMx)AsO (TM = Mn, Fe, Co) with the doping level up to x = 0.1.
While the system remains semiconducting, doping with Sr and Mn results in
ferromagnetic order with TC ~ 30K, and doping with Sr and Fe results in a spin
glass like state below ~6K with a saturation moment of ~0.02 muB/Fe, an order
of magnitude smaller than the ~0.4 muB/Mn of Sr and Mn doped samples. The same
type of magnetic state is observed neither for (Zn,Fe) substitution without
carrier doping, nor for Sr and Co doped specimens.Comment: Accepted for publication in EP
An Efficient Decomposition Algorithm for Large-Scale Network Slicing
In this paper, we consider the network slicing (NS) problem which attempts to
map multiple customized virtual network requests to a common shared network
infrastructure and allocate network resources to meet diverse service
requirements. We propose an efficient decomposition algorithm for solving this
NP-hard problem. The proposed algorithm decomposes the large-scale hard NS
problem into two relatively easy function placement (FP) and traffic routing
(TR) subproblems and iteratively solves them enabling information feedback
between each other, which makes it particularly suitable to solve large-scale
problems. Specifically, the FP subproblem is to place service functions into
cloud nodes in the network, and solving it can return a function placement
strategy based on which the TR subproblem is defined; and the TR subproblem is
to find paths connecting two nodes hosting two adjacent functions in the
network, and solving it can either verify that the solution of the FP
subproblem is an optimal solution of the original problem, or return a valid
inequality to the FP subproblem that cuts off the current infeasible solution.
The proposed algorithm is guaranteed to find the global solution of the NS
problem. We demonstrate the effectiveness and efficiency of the proposed
algorithm via numerical experiments.Comment: 5 pages, 4 figures, accepted for publication in IEEE SPAWC 202
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