Aiming at the problems of inaccurate feature extraction and high complexity of traditional ElectroCardioGram (ECG) detection algorithms based on morphological features, an improved Long Short-Term Memory (LSTM) neural network was proposed. Based on the advantage of traditional LSTM model in time series data processing, the proposed model added reverse and depth calculations which avoids extraction of waveform features artificially and strengthens learning ability of the network. And supervised learning was performed in the model according to the given heart beat sequences and category labels, realizing the arrhythmia detection of unknown heart beats. The experimental results on the arrhythmia datasets in MIT-BIH database show that the overall accuracy of the proposed method reaches 98.34%. Compared with support vector machine, the accuracy and F1 value of the model are both improved.
In Mobile Ad Hoc Network (MANET), the movements of nodes are liable to cause link failures, while the local repair in the classic Ad Hoc On-demand Distance Vector (AODV) routing algorithm is performed only after the link breaks, which has some limitations and may result in the cached data packet loss when the repair process fails or goes on too slowly. In order to solve this problem, an optimized AODV routing algorithm named ARB-AODV was proposed, which can avoid route breaks. In ARB-AODV algorithm, the link which seemed to break was predicted and the stability degrees of the nodes' neighbors were calculated. Then the node with the highest stability was added to the weak link to eliminate the edge effect of nodes and avoid route breaks. Experiments were conducted on NS-2 platform using Random Waypoint Mobility Model (RWM) and Constant Bit Rate (CBR) data. When the nodes moved at a speed higher than 10m/s, the packet delivery ratio of ARB-AODV algorithm maintained at 80% or even higher, the average end-to-end delay declined up to 40% and the overhead of normalized routing declined up to 15% compared with AODV. The simulation results show that ARB-AODV outperforms AODV, and it can effectively improve network performance.
To solve the problem of Fine Particulate Matter (PM2.5) concentration prediction, a PM2.5 concentration prediction model was proposed. First, through introducing the comprehensive meteorological index, the factors of wind, humidity, temperature were comprehensively considered; then the feature vector was conducted by combining the actual concentration of SO2, NO2, CO and PM10; finally the Least Squares Support Vector Machine (LS-SVM) prediction model was built based on feature vector and PM2.5 concentration data. The experimental results using the data from the city A and city B environmental monitoring centers in 2013 show that, the forecast accuracy is improved after the introduction of a comprehensive weather index, error is reduced by nearly 30%. The proposed model can more accurately predict the PM2.5 concentration and it has a high generalization ability. Furthermore, the author analyzed the relationship between PM2.5 concentration and the rate of hospitalization, hospital outpatient service amount, and found a high correlation between them.
To solve the problems such as low accuracy and poor interpretability of traditional news topic mining, a new method was proposed based on weighted Latent Dirichlet Allocation (LDA) that combined with the information structure characters of the news. Firstly, the vocabulary weights were improved from different angles and the composite weights were built, the more expressive words were got by extending the process of feature items generated by the LDA model. Secondly, the Category Distinguish Word (CDW) method was used to optimize the word order of the generated result, which could reduce the noise and the ambiguity of the topics and improve the interpretability of the topics. Finally, according to the mathematical characteristics of the probability distribution model of the topics, the topics were quantified in terms of the contribution degree from the documents to the topics and the topics weight probability to get the hot topics. The simulation results show that the false negative rate and false positive rate of the weighted LDA model drop by an average of 1.43% and 0.16% compared with the traditional LDA model, and the minimum standard price drops by an average of 2.68%. It confirms the feasibility and effectiveness of this method.
To study the Built-in determined Sub-key Correlation Power Analysis (BS-CPA) proposed by Yuichi Komano et al.(KOMANO Y, SHIMIZU H, KAWAMURA S. BS-CPA: built-in determined sub-key correlation power analysis. IEICE Transactions on Fundamentals of Electronics, Communications and Computer Sciences, 2010,E93-A(9):1632-1638.) based on the data set of dpacontest.org, this paper compared the efficiency of Differential Power Analysis (DPA), Correlation Power Analysis (CPA) and BS-CPA from the number of power consumption trace and success rate, the result shows that although BS-CPA works out nicely in theory, it is far from the reaching of the efficiency claimed by the authors, and then the intermediate was chosen by the relationship between the statement of executed cryptographic device’s register and power consumption. Attack surface was narrowed by the reduction of noise and ghost peak, the most relative point was filtered out. Compared with the whole point attack, the biggest success rate of partial point attack can be increased by 60% to crack the 64 bit keys for the same number traces. The experiment results prove that the improved model is able to increase the efficiency and decrease the needed power consumption trace for the same success rate, and the result is stable.
In heterogeneous information systems, some access control techniques and policies were adopted to protect the resources. It was necessary to coordinate security policies between interconnected enterprises. By this way the information could be shared effectively. A primitive ticket-based authorization model was proposed to manage disparate policies in information enclaves. The formal description and the computation of the privilege were also given.
The normal model checking technology to analyse security protocol was introduce. As an example, a model for Needham-Schroeder Public-Key Protocol was constructed by using Promela language. SPIN was used to check and discover an attack upon the protocol. The method is easy to extend to check the security protocol which involves several agents.