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In order to solve the current power system prediction accuracy is not high, it is difficult to simulate the distribution of the actual power load and can not predict the future load reasonably. In this paper, a power load forecasting model based on improved random forest is proposed, and the correlation of factors affecting load is analyzed by mining association rules. The parameters such as the number of decision trees and the number of split features in the RANDOM forest algorithm are optimized by the gradient descent method to obtain the optimal value of parameters, so as to obtain the optimal performance of the random forest algorithm. An example is given to analyze the load data of a certain city in Gansu Province. The experimental results show that compared with the prediction model based on the traditional random forest algorithm, the prediction model proposed in this paper has better prediction performance.

In this paper, a rigorous orbit attitude estimation algorithm for low-Earth-orbit (LEO) spacecrafts is presented in the presence of earth oblateness and atmospheric drag. The spacecraft orbit attitude kinematics for arbitrary eccentric orbit is derived. The variational orbit angular velocity is computed using the inertial position and velocity. The effects of the orbit estimation precision with respect to orbit attitude determination are analyzed. An extended Kalman filter (EKF) is derived to estimate the orbit attitude, inertial position and velocity, as well as gyro bias. Simulation results indicate that the proposed algorithm has better estimation performance for the orbit attitude over than the traditional algorithm.

The present work introduces a new blind Kriging model for approximating expensive computer experiments. The core contribution is the imposition of a nonstationary Gaussian prior on the regression parameter so as to achieve more adaptive mean modeling along with variable selection. With the technique of Cholesky decomposition, all the parameters involved in blind Kriging are estimated by the expectation-maximization scheme automatically. Empirical studies with a benchmark dataset demonstrate that our method achieves comparative performance in terms of the prediction accuracy.

The nonparametric blind deconvolution, either single or multi-shot, has been intensively studied since Fergus et al.'s variational Bayesian approach to camera shake deblurring [1]. However, in the current literature there is always a gap between the two highly related problems; single and multi-shot blind deconvolution are modeled and solved independently, lacking a unified optimization perspective. We attempt to bridge the gap between the two problems in this paper, via constructing a simple, rigorous and unified minimization functional which couples the variational Bayesian and maximum-a-posteriori principles. The new approach is depicted using a directed graphic model, in which the sharp image and the inverse noise variance associated with each shot are treated as random variables, while the blur-kernel, in difference from existing variational Bayesian methods, is just modeled as a deterministic parameter. With a universal, three-level hierarchical prior on the latent sharp image and a Gamma hyper-prior on each inverse noise variance, the single/multi-shot blind deconvolution is formulated into an l0.5-norm regularized negative log-marginal-likelihood minimization problem. By ideas of expectation-maximization, majorization-minimization, mean field approximation, and iteratively reweighted least squares, all the unknown quantities of interest, including the sharp image, the blur-kernel, the inverse noise variance, as well as other related parameters are estimated automatically. In comparison to existing single/multi-shot methods, the proposed method is not only more flexible, but also more adaptive while with less implementational heuristics. Experimental results on Levin et al.'s [2] benchmark data set demonstrate the effectiveness and superiority of the proposed framework.

The logistics business outsourcing is increasingly developed to be the trend of enterprise logistics management in the 21st century. Although there is a large scale of logistics outsourcing, more companies feel low-satisfaction about logistics providers. Taking a steel production company as the research object, with quantitative analysis methods, which will help to design the effective logistics business outsourcing operation system and build up the relative model according to the specific operation of the actual situation of the enterprises. Through certain of example models analysis, which will also clarify the necessity and feasibility of logistics business outsourcing which shows the theoretical and practical significance for the companies during the period of transferring from self-steering to logistics outsourcing.

System Dynamics (SD) is used to build the model of dynamic driven factors of cleaner production system, and by using the driver variables of simulation model, and the relevant test function, the knock-on effects of different factor changes on the system are simulated. The development of the enterprises clean production implementation is simulated, combining with the involvement of different driving contexts and the introduction of different variables. The study shows that: the Intention Level of enterprises implementing cleaner production will be grow slowly in the foreseeable future periods when there’ s no policy control or any other measures to promote, but it will makes the biggest change in the development trends if the hindrance of decision-makers acts is reduced, and followed by the weakening of the government regulation, the reducing of “ green” demands pressure from Stakeholders, the elimination of obstacles to the spread of clean technologies. But the trend of the development varies much more than any single factor effect when assembled these four categories of key factors.

Aligning protein sequences using a score matrix has became a routine but valuable method in modern biological research. However, alignment in "Twilight Zone" is still a challenging issue. New score matrices such as Position Specific Score Matrix and structural context-based matrix have been issued to deal with it, whereas generalized matrices are still useful in pairwise alignment and/or some steps of generating profiles. Family-specific matrices have been proved effective in improving alignment, whereas the generalization of them is reduced. ALPHASUM, a score matrix based on structure alignment of low identity all-alpha proteins is constructed. Performance comparison suggests substitution pattern difference between all-alpha proteins and all proteins and indicates that alignment of all-alpha proteins in "Twilight Zone" can be improved by using alpha class-specific matrix and gap penalties. The implication between structure-derived matrix and influence of amino acid substitution to structure is also suggested.

Sequence alignment has been a most commonly used method in modern biological research. However, sequence alignment in "Twilight Zone" is still a challenging issue. Three protein class-specific matrices are constructed to investigate whether alignment in "Twilight Zone" can be improved by using class-specific matrices and gap penalties. The substitution pattern differences between different protein classes do improve the performances of the three class-specific matrices. Analyzing amino acids substitution pattern based on different matrices also suggests important information for protein sequence design.

Medical products of PTFE electret that come in contact with the body or bodily fluids must be sterilized before use. That sterilization method is selected is important because the stability of space charge in electrets may be affected differently to various forms of sterilization. In this paper, charge storage stability in porous polytetrafluoroethylene (PTFE) film electrets were investigated by means of corona charging at room or elevated temperature, isothermal and thermal stimulating surface potential decay, as well as open-circuit thermally stimulated discharge (TSD) current spectra after ultraviolet (UV) and gamma (cobalt 60) radiation sterilization. The results showed that the surface potential remain above 95% of the original level in porous PTFE after UV-irradiation in the range of 3.2 mW/cm/sup 2/ for 2 hours, however, the charges injected in porous PTFE were almost completely removed after radiation with gamma-radiation at doses of 15 kGy. UV-irradiated porous PTFE films, one side coated with aluminum electrodes and negative corona charged, show peak position shifts towards the higher temperature in their TSD curves as compared with those of unirradiated samples. It is available for sterilizing medical electret products of porous PTFE films by UV radiation.

The main object of this study was to systemically evaluate the effect of porous PTFE/PE/PP electret on lidocaine transdermal delivery and to compare its enhancing effect with some commonly used chemical permeation enhancers, that is propylene glycol, oleic acid and menthol. The composite electret was prepared by heat melting method at 130/spl square/. The modified Franz diffusion cell was used to carry out the in vitro permeation experiment and a high performance liquid chromatography (HPLC) was employed to analyze the drug concentration. The drug solution containing no chemical permeation enhancer or no electret application was taken as control group. The results indicated that: (1) The feasibility of using porous PTFE/PE/PP electret to enhance the lidocaine transdermal delivery was achieved by applying positively charged electrets with different surface potentials. The enhancing effect was proportional to the surface potential of the electret. (2) The chemical permeation enhancers used were shown to be less effective than the +1000 V electret on lidocaine transdermal permeation. The 24 hour's cumulated permeation amount of lidocaine reached to 3.649, 6.029, 8.619, 6.330 and 17.218 mg for control group, 10% oleic acid, 20% propylene glycol, 1% menthol and porous PTFE/PE/PP electret, respectively. In conclusion, positively charged electret can be used as the enhancer to increase the transdermal permeation of lidocaine.