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This paper firstly researches the ideological and political education in higher education institutions in the background of the big data era and puts forward the innovation strategy of ideological and political education mode in higher education institutions in the big data era. Secondly, it studies the application of data mining technology in colleges and universities for ideological and political education. Based on data mining technology, the data on ideological and political education is determined by the clustering algorithm, followed by a quantitative examination of the policy text of ideological and political education of colleges and universities by calculating the quantitative statistical analysis of policy text, word frequency, and word cloud analysis. Then, the research subjects were selected, and the initial data were obtained using questionnaires, further pre-processing, and further empirical analysis of ideological and political education based on data mining technology. The consequences show that the proportions contained in the three types of score bands, namely 17.99%, 59.38% and 9.96%, basically match with the sample proportions accounted for by the three types of grades assessed by clustering, namely 30.51%, 62.02% and 8.47%, which confirms that such a model of data mining adopted according to the quantitative table of ideologic and politic education assessment in higher education institution is a very successful model. This study contributes to the innovation of online ideological and political education work in higher education institutions in the context of big data.

Injuries at the tendon-bone interface are very common in the field of sports medicine, and healing at the tendon-bone interface is complex. Injuries to the tendon-bone interface can seriously affect a patient’s quality of life, so it is essential to restore stability and promote healing of the tendon-bone interface. In addition to surgical treatment, the healing of tendons and bones can also be properly combined with extracorporeal stimulation therapy during the recovery process. In this review, we discuss the effects of extracorporeal shock waves (ESWs), low-intensity pulsed ultrasound (LIPUS), and mechanical stress on tendon-bone healing, focusing on the possible mechanisms of action of mechanical stress on tendon-bone healing in terms of transcription factors and biomolecules. The aim is to provide possible therapeutic approaches for subsequent clinical treatment.

Pure titanium (Ti) is usually deformed at elevated temperatures due to its poor formability at room temperature (RT), resulting in its strength reduction after deformation. Applying pre-strain combining with resistance heating (RH) method, which can be conducted at one procedure, was proposed to enhance its plasticity in this work. The influence of the proposed process on tensile deformation of pure Ti foils with 50 μm thick was investigated using a RH assisted tensile testing system. Full strain field was measured by a digital image correlation (DIC) system with laser speckles. Uniaxial tensile pre-strain ranging from 1% to 2% was applied at a low temperature of 160 °C with relatively high nominal strain rates of 10−2 and 10−1 s−1. Then tensile tests were conducted at RT with a nominal strain rate of 10−3 s−1. As results, although the ultimate tensile strength (UTS) slightly decreased with increasing pre-strain, the maximum decreasing rate was within 4%, indicating that the effect of pre-strain on UTS is negligible. The strain distribution analyzed from DIC was relatively uniform at UTS. Uniform elongation increased with increasing pre-strain. The maximum increasing rate achieved 36%. It is confirmed that the heating rate using RH for heating Ti foils with 50 μm thick is about 340 times larger than that for heating Ti sheets with 1 mm thick. The quick response of RH makes it possible for the application of the proposed process to mass production for manufacturing microparts.

The full-field deformation characterizations of a metal undergoing large plastic strains are difficult to be obtained from the conventional true stress-strain curves. In this study, we proposed using a simple non-contacting technique, digital image correlation (DIC) with laser speckles, to evaluate large plastic deformations of metals, especially for thin metal foils and for the forming at high temperatures. The feasibility and accuracy of this DIC technique were confirmed by conducting uniaxial tensile tests using different materials. As results, the measured strains indicated a good accuracy with an error range of 6% in measuring the large plastic deformation at room temperature and 10% in measuring a large strain up to 0.6 at a high temperature of 400 °C. The strain distribution measured by DIC with laser speckles and with artificial speckles showed good agreement, confirming the feasibility of this DIC technique for measuring large plastic deformations. By using this technique, the evolution of plastic zone was successfully investigated for thin metal sheets with a thickness of 0.5 mm. Furthermore, the strain fields involving localizations of 50 μm thick metal foils forming at room temperature and a large plastic deformation of metal tubes forming at 400 °C were evaluated qualitatively and quantitatively.

Blast waves generated from the muzzles of weapons may exert negative effects, such as shock waves and impulse noise. If the weapon is fired with a muzzle brake, these effects are recognized to be more severe. This paper discusses the influence of the muzzle brake on certain aeroacoustic noise characteristics based on numerical simulations and a corresponding experiment. The impulse noise, which is induced by complex jet flows discharging from small caliber rifles with muzzle brakes, is focused in this study. Computational fluid dynamics (CFD) and computational aeroacoustics (CAA) are combined to calculate the muzzle flow field and jet noise for cases with and without a muzzle brake, and then the data sets are carefully compared. The simulations indicate that the muzzle brake alters the muzzle flow field and directional distribution of the jet noise compared to a rifle sans muzzle brake. Deviations less than 7.6% between experimental data and simulation results validate the simulation model. The results presented in this paper may provide a workable reference for the prediction of muzzle noise and the optimization of muzzle brake designs.

The problem of finding link-disjoint paths under multiple additive QoS constraints was studied.Since the existing algorithms depended on network’s structure and could not guarantee to find feasible solutions for arbitrary net-works,a novel algorithm called multiple constrained link-disjoint path routing algorithm（MCLPRA） was proposed.MCLPRA was based on SAMCRA and didn’t rely on the network’s structure.By introducing the parameter to control its search depth,dividing the solution space into different classes and performing searching according to the classes respectively,MCLPRA was able to obtain the feasible solutions for arbitrary networks.Theoretic analysis shows that MCLPRA can get the feasible and optimal solutions when traditional schemes can not.Comprehensive simulations also show that MCLPRA has better performances than existing algorithms in terms of higher average successful rate of getting feasible solutions with shorter average total length of the obtained path pair.

A detailed study on the BitTorrent sharing objects popularity was presented.The objects-sharing popularity and objects-downloading popularity of four BitTorrent trackers was measured and modeled by means of actively probing the tracker server, and the model was tested by χ2 fitting test.The experiment results indicate that the peer-to-peer sharing objects popularity is very unbalanced, that is, there are almost 60% of total share copies for the most 20% popular objects and there are above 60% of total downloads for the most 10% popular objects.Moreover, the experiment results also indicate that the objects-sharing popularity can be well modeled by Zipf distribution and perfectly modeled by Zipf-Mandelbrot distribution, and that the objects-downloading popularity can not be modeled by Zipf distribution and can be perfectly modeled by Zipf-Mandelbrot distribution.

A congestion control mechanism LAP （link layer adaptive pacing） for wireless mesh networks was presented,which controlled the transmission rate of wired-to-wireless flows at the mesh gateway to avoid serious interference among hops brought by excessive data transmission. The algorithm considered each flow as an object,which could not only improve the performance of multihop flows,but also keep network fairness. Besides,the control mechanism was re-alized at link layer and needn’t modify the existing transport or routing protocols. The simulation results showed that the network performance controlled by LAP exceeded 802.11 networks greatly,and outperformed current leading algorithms obviously too.

By analyzing the correlation structure of multifractal tree,it was found that multifractal has the ability to con-vert the non-stationary long-range dependence（LRD） trace to a series of short-range dependence（SRD） sequence.Based on this property,a FIR neural network traffic predictor combined with multifractal was proposed.Because the LRD fea-ture of trace is used,the multi-step performance of proposed method is much better than traditional methods.

By assisting with resistance heating, the material formability can be improved, and more homogeneous material flow can be obtained. In this study, finite element (FE) models for an analysis of microbending process assisted by resistance heating were developed. Coupled thermal-electrical procedure and coupled thermal-displacement dynamic explicit procedure were conducted to analyze the temperature distribution and material deformation, respectively. And static implicit procedure was carried out for the analysis of springback behavior. The simulation results show that the temperature distribution of the blank is caused by the difference in electrical current density, which influences the material deformation as well as springback behavior. And the spingback angle decreases with increasing forming temperature. The temperature distribution and springback angle obtained from the simulation show the same tendency with the experiments, which confirmed the feasibility of the developed FE models. By using the developed FE models, the effects of the temperature distribution on material behavior can be obtained, and the springback angle for microbending process assisted by resistance heating can be predicted precisely. The possibility of reducing springback and improving the accuracy of the products by designing the process efficiently is demonstrated.

The correlation function and marginal distribution of multipliers at each layer were investigated in multifractal multiplicative process.Based on the lemmas gained,a new multifractal MPEG-4 video traffic model（PMFM,predict-able MFM）was proposed.By modeling the coarsest coefficients with the auto-regressive（AR） process,PMFM has the ability of traffic prediction that traditional MFM do not have.Furthermore,the model stability and robustness were also improved by changing the way of parameter estimation.