The traditional Deep Learning (DL)-based multi-objective solvers have the problems of low model utilization and being easy to fall into the local optimum. Aiming at these problems, a Multi-objective Optimization model for Unmanned aerial vehicles Trajectory based on Decomposition and Trajectory search (DTMO-UT) was proposed. The proposed model consists of the encoding and decoding parts. First, a Device encoder (Dencoder) and a Weight encoder (Wencoder) were contained in the encoding part, which were used to extract the state information of the Internet of Things (IoT) devices and the features of the weight vectors. And the scalar optimization sub-problems that were decomposed from the Multi-objective Optimization Problem (MOP) were represented by the weight vectors. Hence, the MOP was able to be solved by solving all the sub-problems. The Wencoder was able to encode all sub-problems, which improved the utilization of the model. Then, the decoding part containing the Trajectory decoder (Tdecoder) was used to decode the encoding features to generate the Pareto optimal solutions. Finally, to alleviate the phenomenon of greedy strategy falling into the local optimum, the trajectory search technology was added in trajectory decoder, that was generating multiple candidate trajectories and selecting the one with the best scalar value as the Pareto optimal solution. In this way, the exploration ability of the trajectory decoder was enhanced during trajectory planning, and a better-quality Pareto set was found. The results of simulation experiments show that compared with the mainstream DL MOP solvers, under the condition of 98.93% model parameter quantities decreasing, the proposed model reduces the distribution of MOP solutions by 0.076%, improves the ductility of the solutions by 0.014% and increases the overall performance by 1.23%, showing strong ability of practical trajectory planning of DTMO-UT model.
Neuromarketing, by which consumer responses to advertisements and products are analyzed through research on human brain activity, is receiving new attention. Aiming at neuromarketing based on ElectroEncephaloGraphy (EEG), a method of consumer preference prediction based on deep learning neural network was proposed. Firstly, in order to extract features of consumer's EEG, five different frequency bands of EEG topographic videos were obtained from multi-channel EEG signals by using Short Time Fourier Transform (STFT) and biharmonic spline interpolation. Then, a prediction model combining five three-Dimensional Convolutional Neural Networks (3D CNNs) and multi-layer Long Short-Term Memory (LSTM) neural networks was proposed for predicting consumer preference from EEG topographic videos. Compared with the Convolutional Neural Network (CNN) model and LSTM neural network model, the average accuracy of consumer-dependence model was increased by 15.05 percentage points and 19.44 percentage points respectively, and the average accuracy of consumer-independence model was increased by 16.34 percentage points and 17.88 percentage points respectively. Theoretical analysis and experimental results show that the proposed consumer preference prediction system can provide effective marketing strategy development and marketing management at low cost.
Focusing on the issue that the HBase storage without spatio-temporal index degrades the traffic data query performance, some HBase spatio-temporal indexes based on row keys were proposed for massive traffic data. Firstly, the dimensionality reduction method based on Geohash was used to convert two-dimensional spatial position data into a one-dimensional code. Then the code was combined with the temporal dimension. Secondly, four index models were put forward based on combination order, and the structures of the models and their adaption conditions for traffic data query were discussed. Finally, the algorithm of index creation as well as traffic data query algorithm was proposed. Experimental results show that the proposed HBase spatio-temporal index structure can effectively enhance the traffic data query performance. In addition, the query performance of four different spatio-temporal index structures in different data size, different query radius and different query time range were compared, which verified the different adaption scenes of different index structures in traffic data query.
In order to improve the robustness and accuracy of relative orientation, an approach combining direct resolving and iterative refinement for relative orientation was proposed. Firstly, the essential matrix was estimated from some corresponding points. Afterwards the initial relative position and posture of two cameras were obtained by decomposing the essential matrix. The process for determining the only position and posture parameters were introduced in detail. Finally, by constructing the horizontal epipolar coordinate system, the constraint equation group was built up from the corresponding points based on the coplanar constraint, and the initial position and posture parameters were refined iteratively. The algorithm was resistant to the outliers by applying the RANdom Sample Consensus (RANSAC) strategy and dynamically removing outliers during iterative refinement. The simulation experiments illustrate the resolving efficiency and accuracy of the proposed algorithm outperforms that of the traditional algorithm under the circumstance of importing varies of random errors. And the experiment with real data demonstrates the algorithm can be effectively applied to relative position and posture estimation in 3D reconstruction.
A low power branch encoding method was presented for decreasing the SoC bus power dissipation. This method's basic principle is: for the address bus, when the address bus is sequential, the address bus is frozen, and when the address bus is non-sequential, the window size is adjusted dynamically to apply the Bus-Invert (BI) method on the address bus. For the data bus, two threshold values are figured out for different data size respectively. If the Hamming distance locates between these two threshold values, the valid-data-channel switching dense area is found and inverted, otherwise applies the BI encoding. This method's encoding and decoding circuits are realized in the Advanced High Performance Bus (AHB) system. The experimental result demonstrates that compared with uncoded situation, this method decreases the address/data bus toggle rate by 51.2%/22.4%, and the system power is reduced by 28.9%. Compared with T0,BI and other encoding methods realized in the same system, the branch encoding is more superior in the toggle rate and power dissipation.