Applied Mechanics and Materials Vols. 198-199

Abstract: Using the advantages of exhaustive dynamic programming algorithm, on the basic ideas of the global optimal solution is derived based on local optimal solution, this paper propose a new structural selection join algorithm. The algorithm connects to the sub-tree, and then connects to the structure of the whole. Though not guaranteed optimal solution, this algorithm can improve much in the time complexity, reduce the search space and improve efficiency.

Abstract: According to the definition of environment, four classification of environment are known. Among them, the classification according to the components is the most widely recognized one. However, also has some limitations. Facing climatic change, the New Environmental Paradigm (NEP) from the anti-anthropocentrism will become the key measuring method. After subdivided environment according to the logic of anti-anthropocentrism, I find that environment classification according to the components is relevantly scientific, but it still is unable to meet the requirements of current and further researches. In order to fix the research of environment, I try to give the correspondence classification. Data using 700 items related to environment from the CNKI (China National Knowledge Infrastructure). Main fields of current environment research have been analyzed. For better understanding of “environment” especially on the research arena, “virtual environment” should be adding in the definition of environment.

Abstract: The alarm correlation analysis based on fuzzy association rules mining is the popular and cutting-edge field of the network fault diagnosis research. In the application environment of alarms in communication networks, a new algorithm of the fuzziness of alarms which is called FKMA (Fuzzy K-Means of Alarms algorithm) is proposed .During the process of fuzziness, there are two methods of sorting the center. Simulations are carried out to the comparison of the two methods. The fuzziness of alarms is effectively realized. And fuzzy association rules mining are achieved. The advantages and efficiency of FKMA are demonstrated by experiments.

Abstract: The sports injury is common in training, hindered the athletes to further improve the sports results. There are many factors in sports injury, How to accurately identify the core, the key factors, is the question needs to be solved in the sport and the medical. The paper fully aware of the advantages of the attribute reduction, putting forward an attribute reduction algorithm based on mutual information, by introducing the concept of information theory, and proving it’s reliability.

Abstract: The sintering blending is a complex nonlinear optimization problem. The traditional single algorithm can not meet the requirement of good quality of sinter and lowest costs well. So, a hybrid optimization method of particle swarm and ant colony algorithm was proposed. The method gives full play to the global convergence of particle swarm optimization algorithm, takes it as a preliminary search, then use the positive feedback mechanism of ant colony algorithm for the exact solution, to make these two algorithms to reach a complementary, in order to get a rapid exact solution. The simulation results show that the proposed hybrid algorithm has fast convergence and high accuracy, which can effectively reduce the sintering cost.

Abstract: According to the limited accuracy of the current MEMS inertial sensors, the motion displacement method obtained by direct acceleration of the second integration to will bring large errors, this paper presents an motion tracking solution method for tracking three-dimensional arm movement ,by changing three-dimensional arm motion into the translational tracking of the plane, complementary filter for multi-sensor data fusion for data integration and correction is designed and the translational tracking method is introduced detailed, The experimental results show that the proposed method can improve tracking accuracy and stability in arm writing motion without noticeable drift.

Abstract: Hilbert-Huang transform is developed in recent years dealing with nonlinear, non-stationary signal analysis of the complete local time-frequency method, recurrence plot method is a recursive nonlinear dynamic behavior of time series method of reconstruction. In this paper, Hilbert-Huang Transform empirical mode decomposition (EMD) and the recurrence plot (RP) method, a new voice activity detection algorithm. Firstly, through the speech and noise based on the empirical mode decomposition and multi-scale features of the different intrinsic mode function (IMF) on a time scale filtering and nonlinear dynamic behavior of the recurrence plot method, quantitative Recursive analysis of statistical uncertainty for endpoint detection. Simulation results show that the method has a strong non-steady-state dynamic analysis capabilities, in low SNR environment more accurately than the traditional method to extract the start and end point of the speech signal, robustness.

Abstract: In order to obtain accurate and high-speed data transmission, the orthogonal frequency division multiplexing(OFDM) technology is introduced and it is a kind of a multi-carriers modulation technology with high efficiency in the use of frequency band and characteristics of strong anti-interference ability. The fractionally spaced OFDM frequency domain equalization algorithm based on modified pilot sequences is proposed. In this proposed algorithm, one-dimensional linear interpolation method is used to estimate the frequency domain response of all subcarriers by part of the subcarriers’ frequency domain response with reducing the number of transmitted pilot sequences, and received signals are oversampled to acquire more detailed channel information. The computer simulations in underwater acoustic channel show that the performance of proposed method outperforms the single-carrier system and traditional OFDM system.

Abstract: A novel spatial modulation scheme based on Space-Shift Keying (SSK) modulation is introduced for MIMO system. The proposed scheme doubles the spectrum efficiency of SSK by assigning unique symbols to different combinations of antenna indexes per symbol duration, while retaining the SSK’s inherent advantages. The optimal detector is utilized at the receiver simultaneously. Analytical and simulation results show: 1) in Rayleigh fading channel scenario，the obtained gains in SNR for the same spectral efficiency of the proposed scheme over amplitude/phase modulation (APM), vertical Bell Labs layered structure (V-BLAST) and spatial modulation (SM) systems are obvious; 2) under the correlated channel assumption, the new one still outperforms SM and V-BLAST clearly, which indicates the new one is more robust in the presence of channel correlation.

Abstract: Orthogonal frequency division multiple access (OFDMA) is a promising technique for achieving high downlink capacities in next generation wireless communication system. An OFDM system has the advantage that multiple users can be scheduled at the same time in a frequency-selective channel. Proportional fair resource scheduling algorithm can guarantee the fairness among multiple users. Compared to the conventional fixed modulation, link adaptation modulation can select the most appropriate modulation scheme on each sub-carrier according to the current link qualify, this can be used to enhance system throughput. However, the overhead cost of feeding back channel state and modulation mode information of every sub-carrier for every user is very high. Cluster feedback scheme can greatly reduce the feedback overhead. In this paper, based on cluster feedback, an adaptive modulation with proportional fair scheduling algorithm is proposed. The analysis and simulation result verify that the introduced scheme is effective in improving system throughput and has fairness among users.