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In this paper, we propose a general stochastic model for virus propagation on the online social network. The model considers the time interval of users re-login in SNS network, the number of users in one's friend list, and propagation mechanism, utilizes SEIR model, which is an epidemic model, and finally establishes the dynamic evolution equations. The dynamic evolution equations describe the change...
Aiming at the identification difficulty of texture-rich veneer defect images, a new variation model based on coupling image texture-structure decomposition and edge extraction is proposed in this paper. Firstly, An advanced AAFC structure-texture decomposition model is obtained through extending the regular items of AAFC model; Secondly, using the semi-quadratic regularization method to obtain a new...
the optimization in transients of hydropower station is an issue of multi variables and multi-objectives. Large oscillation transient process and small fluctuation stability have a strong relationship with the character of Tailrace Tunnel. By theory analysis and numerical simulation, this article analyses the effect of the length of free surface flow and pressure flow on pressure in draft and small...
High concentration particles with ultrafine diameter (dp=100nm) diffusion and coagulation in planar jet flow were simulated. The initial particle volume fraction is 10%. The Large Eddy Simulation (LES) was adopted to calculate the flow field. The Taylor-series expansion method of moments (TEMOM) model was used to transform and close the particle General Dynamic Equation (GDE) which can simulate the...
The sonic nozzle airflow standard facilities are applied widely throughout the world and can be divided into two categories, negative pressure and positive pressure methods. The latter is better than the former at calibrating flowmeters and analyzing the impact of pressure and density on performance of flowmeters. This paper discusses several key issues about establishing standard facilities by the...
In this paper, we propose a method to extract multi-parameters regarding to tomography from PolInSAR data and investigate the potential of applying them to classify the forest vegetation species. We first propose a general volume scattering model that includes three basic scattering profile structures according to the change of extinction. Then three basic geometries of trees are introduced and their...
The function of reactive power optimization (RPO)is to realize the reactive power of the electric fence and optimal control of voltage in order that the whole network's operation level can be improved and the loss of operation of power network can be reduced. Recently, the research of ORP is mainly focus on the handling of non-liner function and discrete variables and the convergence of the algorithm,...
In Western corporate finance theory, the Pecking order Theory suggests that when the company needs financing externally, it should firstly debt financing then equity financing. The reason is that the company will face more serious adverse selection in equity financing. However, Chinese enterprises usually have a strong preference on equity financing, this article estimates the intrinsic IPO value...
Ocean-land segmentation is a basis for oceanic targets detection for SAR imagery. The traditional manual segmentation method can acquire a fairly good result, while it is unable to achieve a satisfying efficiency. Thus the manual method is unsuitable for batch processing. Ocean map based land masking method requires a priori information, which restricts its application. This paper presents an automatic...
Due to the requirement of the inverse planning process, TPS(treatment planning system) of IMRT (Intensity Modulated Radiation Therapy) needs accurate dose calculation method with high speed. A superposition /convolution algorithm for photon beams is presented in this paper based on Monte Carlo calculation. The dose distribution can be calculated by the convolution of energy fluence and pencil beam...
With the advance of new technology, PET systems nowadays have much higher sensitivities than before with the adoption of faster scintillators, faster electronics, larger solid angle detectors and full 3D data collection mode. All of these lead to the increasing of the random coincidences that will affect the image quality. Accurate random correction is important for the quantitative imaging in PET...
Calibrating nonlinear mobile sensors in-field is a challenging task due to the unavailability of controlled signal field and pre-calibrated sensor devices. In this paper, we propose a Density Guided blind Calibration (DGC) scheme for nonlinear mobile sensors by approximating the nonlinear calibration functions using piecewise linear functions. The DGC scheme exploits the fact that sensors moving in...
In a (t, n) threshold proxy signature scheme, which is a variant of the proxy signature scheme, the proxy signature key is shared among a group of n proxy signers delegated by the original signer. Any t or more proxy signers can cooperatively sign messages on behalf of the original signer. Recently, Qian et. al. proposed a pairing-based threshold proxy signature scheme. However, we show that their...
On the optimal design of CMOS operational amplifier, it is very difficult to improve the circuitpsilas performance by manual design. So a quantum-behaved particle swarm optimization algorithm (QPSO) based on the swarm intelligent technology is presented to get the global optimal solution. This algorithm is mainly to optimize the position of the particle instead of solve the circuit performance analytic...
In-field calibration of sensor devices is known to be a challenging problem because there is often no access to a controlled signal field and/or a pre-calibrated device to provide the ground truth. Nonlinear characteristics of sensor devices make the calibration problem even harder. In this paper, we describe two blind calibration schemes for nonlinear mobile sensor nodes: nullspace based calibration...
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