Device-to-Device(D2D) communication leverages the local computing and caching capabilities of the edge network to meet the demand for low-latency, energy-efficient content sharing among future mobile network users. The performance improvement of content sharing efficiency in edge networks not only depends on user social relationships, but also heavily relies on the characteristics of end devices, such as computation, storage, and residual energy resources. Therefore, a D2D content sharing mechanism was proposed to maximize energy efficiency with multidimensional association features of user-device-content, which took into account device heterogeneity, user sociality, and interest difference. Firstly, the multi-objective constraint problem about the user cost-benefit maximization was transformed into the optimal node selection and power control problem. And the multi-dimensional knowledge association features and the graph model for user-device-content were constructed by processing structurally multi-dimensional features related to devices, such as computing resources and storage resources. Then, the willingness measurement methods of users on device attributes and social attributes were studied, and a sharing willingness measurement method was proposed based on user socialization and device graphs. Finally, according to user sharing willingness, a D2D collaboration cluster oriented to content sharing was constructed, and a power control algorithm based on shared willingness for energy efficiency was designed to maximize the performance of network sharing. The experimental results on a real user device dataset and infocom06 dataset show that, compared to nearest selection algorithm and a selection algorithm without considering device willingness, the proposed power control algorithm based on shared willingness improves the system sum rate by about 97.2% and 11.1%, increases the user satisfaction by about 72.7% and 4.3%, and improves the energy efficiency by about 57.8% and 9.7%, respectively. This verifies the effectiveness of the proposed algorithm in terms of transmission rate, energy efficiency and user satisfaction.
In order to improve the accuracy and universality of computer-assisted classification algorithm, a Electrocardiography (ECG) beat classification algorithm based on cluster analysis was presented in this paper. The algorithm considered that one patients' ECG beats repeated periodically, and used the method of two-stage cluster analysis, and selecting representative ECG beats, combined with the diagnosis of cardiac physicians to achieve accurate ECG beat classification rate. In order to verify the accuracy of the algorithm, using the internationally standard database MIT-BIH arrhythmia database, the ECG beat classification method and the accuracy evaluation method specified by AAMI/ANSI standard were used to perform simulation experiments, the final overall classification accuracy rate is 99.07%. Compared with Kiranyaz' method(KIRANYAZ S, INCE T,PULKKINEN J, et al. Personalized long-term ECG classification: A systematic approach[J]. Expert Systems with Applications, 2011, 38(4): 3220-3226.), this method does not require specific training step, and the sensitivity of the ECG beats which labeled as S raise to 89.82% from 40.15%, significantly improving classification algorithm's generalization capability.
Model Driven Architecture (MDA) refers to the method and standard system for the application of model technology in software development proposed by Object Management Group (OMG), the core idea of which includes the modeling of platform-independent model and the transformation of platform-specific model. The framework was realized by programming based on Meta Object Facility 2.0 (MOF2.0) Query/View/Transformation (QVT) standard definition, and it could achieve transformation of meta model to specific N-layer application class and realize main functions of the program, thus greatly improving the development efficiency. The flexibility of model-driven transformation and diversity of function realization achieved by programming were verified, including the description of model specification by XML documents and the integrity of code generation