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Jia B.,Heilongjiang University | Li J.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province
Communications in Computer and Information Science

To overcome the defects that previous research cannot recognize human activities accurately in real-time, we proposed a novel method, which collects data from the accelerator and gyroscope on a mobile phone, and then extracts features of both time domain and frequency domain. These features are used to learn random forest models offline, which make our mobile app can recognize human activities accurately online in real-time. Verified by theoretical analysis and a large number of contrast experiments, the recognition is rapid and accurate on mobile phones with accuracy at 97%. © Springer-Verlag Berlin Heidelberg 2015. Source

Guo Y.-H.,Heilongjiang University | Wang X.,Heilongjiang University | Wang X.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province
Xitong Gongcheng Lilun yu Shijian/System Engineering Theory and Practice

In order to improve the network spatial reuse and maximize the network throughput, this paper presents a physical conflict model based power allocation and link scheduling algorithm (PPLA). Firstly, PPLA picks available set of parallel links using hexagon coloring method. With physical conflict model, it further obtains the minimum power vector which corresponds to parallel links set. The experimental results indicate that the algorithm can increase network spatial reuse ratio and improve throughput significantly. Source

Wan K.,Heilongjiang University | Lu J.,Heilongjiang University | Lu J.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province | Zheng J.,Heilongjiang University | Ren Z.,Heilongjiang University
Communications in Computer and Information Science

The parallel algorithm of the evolutionary distance between different species is implemented by using OpenMP parallel technique in this paper. In order to get the best degree of algorithm parallelism, the method of making loop variable corresponding to the rower and column labels of distance matrix is adopted. It is to say that the double loop can be converted into single loop to improve the parallel efficiency. The serial algorithm and parallel algorithm are compared in this paper. The experiment result shows that the highest speedup is 14.1. It improves the running efficiency of the program. It is a great significance to dealing with massive bioinformatics data. © Springer Science+Business Media Singapore 2016. Source

Ren J.,Heilongjiang University | Jiang Y.,Heilongjiang University | Jiang Y.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province | Gao G.,Heilongjiang University
Tongxin Xuebao/Journal on Communications

Router alias resolution is one of hard problems and important steps for router level Internet topology measurement based on traceroute mechanism, and the topology characteristic of the generated router level topology graph has close relationship with the completeness of alias resolution. The graph with its degrees following power-law distribution was taken as the base-graph, and the shortest paths from one source to others were computed for simulating topology measurement. Experiment results show that it is very probable to see different topology characteristics between the derived graph and the base-graph due to incomplete alias resolution. Most importantly, for large-scale router level topology measurement, the completeness of alias resolution must be improved with the increasing number of probe sources, and in this way the derived topology graph could be approximate to the real topology graph. Source

Ni L.-Y.,Heilongjiang University | Ni L.-Y.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province | Li J.-B.,Heilongjiang University | Li J.-B.,Key Laboratory of Database and Parallel Computing of Heilongjiang Province
Ruan Jian Xue Bao/Journal of Software

To address the problems of transmission delay, transmission conflicts and low throughput in Wireless sensor networks, this paper proposes a channel allocation and routing strategy in Multi-Radio Multi-Channel Networks. The strategy is to dynamically establish a k-ary n-cube topology. It not only uses the optimal static channel allocation algorithm to improve the throughput of nodes but also employs the dimension order routing algorithm to reduce transmission conflicts. This method is suitable for the network of density nodes with many communication conflicts. It can also be used in both single hop and multi hop network environment. The experiment results show that compared with traditional methods, the channel allocation and routing strategy based on the k-ary n-cube topology can effectively reduce end to end delay, network conflicts and energy consumption, prolong the network lifetime and increase the throughput of network. ©2014 ISCAS. Source

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