The tangential angle acquisition of the traditional geometric path tracking algorithm depends on high precision inertial navigation equipments. In order to solve the problem, a new path tracking algorithm based on cubic B-spline curve fitting was proposed. Firstly, the smooth path was generated by fitting the discrete path points in the priori map. Then, the discrete path points were regenerated by using an interpolation method according to the path equation, and the tangential angle at each point was calculated to realize the optimization and tracking of the multi-sensor fusion path. On the real intelligent vehicle experiment platform, the 20 km/h low-speed-circle and the 60 km/h high-speed-straight-path tracking tests for the proposed algorithm were carried out under the two real road scenes. Under the two typical test scenarios of low-speed-large-curvature and high-speed-straight-path, the maximum lateral error of path tracking of the proposed algorithm is kept within 0.3 m. The experimental results show that, the proposed algorithm can effectively solve the problem of traditional geometric path tracking algorithm's dependence on inertial navigation device, and maintain good tracking performance at the same time.

Aiming at the problem that the audio steganography has low utilization of carriers, poor imperceptibility and small embedding capacity, an adaptive audio steganography based on the wavelet packet decomposition and matrix code was proposed. Comparing the differences between the wavelet-packet decomposed coefficients before and after the audio's MP3 compression, the algorithm took the unchanged bits' position of wavelet-packet decomposed coefficients as embedding carriers, which effectively increased the embedding capability. And the algorithm improved the matrix code by using chaotic model to generate random triple-groups, which promoted the safety and efficiency. As for capacity, the proposed algorithm promoted about 30%, compared with the algorithm that directly uses the medium-frequency sub-bands as the carriers. On the aspect of Signal-to-Noise Ratio (SNR), the proposed algorithm promoted about 9%, compared with the matrix steganography that fixes the triple-groups. The experimental results show that the algorithm is correct and can basically satisfies large-capacity and secure communications.

In traditional Proxy Re-Encryption (PRE), a proxy is too powerful as it has the ability to re-encrypt all delegator's ciphertexts to delegatee once the re-encryption key is obtained; And for more than one delegatees, delegator needs to generate different re-encryption key for different delegatee, which wastes a lot of resources in the calculation process. To solve these problems, an identity-based conditional proxy broadcast re-encryption was introduced. The delegator generated a re-encryption key for some specified condition during the encryption, like that the re-encryption authority of the proxy was restricted to that condition only. Moreover, the delegator's ciphertexts could be re-broadcasted to ensure the important communication and save a lot of computation and communication cost. Finally, the theoretical analysis verified the security of the scheme.

Concerning the identification of the accurate model parameters of biological fermentation process, a parameters estimation method for non-structural dynamical model of penicillin fermentation using the Gravitational Search Algorithm (GSA) was proposed. Based on the rule of fermentation mechanism, the appropriate state equations of non-structural dynamical model were chosen; and through virtue of the global searching ability of GSA, the parameters of state equation were estimated and the accurate fermentation model was obtained. The simulation results show that GSA accurately estimated model parameters in penicillin fermentation process, the accuracy of the obtained model can meet the requirements of state estimation and condition control in penicillin fermentation process. Therefore, GSA can be applied to model parameters estimation effectively.

Recently Sun Jin,et al. proposed an dentity-based broadcast encryption scheme against selective opening attack, (SUN JIN, HU YU-PU. Identity-based broadcast encryption scheme against selective opening attack. Journal of Electronics and Information Technology, 2011, 33(12): 2929-2934) and it claimed that the scheme can fight against Selective-Opening Attack (SOA) and has constant-size key and ciphertext in the standard model without random tags. However, this paper proved that their proposal cannot work at all. Furthermore, the authors improved their scheme to be a correct one, and then proved its security in the standard model.

To overcome premature problem of high-dimensional multimodal function in the optimization process by Standard Gravitational Search Algorithm (SGSA), a new Gravitational Search Algorithm based on Feedback mechanism (FGSA) was proposed. Considering the large loss in population diversity during the evolution process, the distance to the optimum position and the distance to its nearest neighbor were introduced into the proposed algorithm to balance the trade-off between exploration and exploitation ability. Mutation operation was also embedded into FGSA. The test results of four benchmark functions demonstrate that FGSA has much better stability and accuracy than SGSA in finding global optimum. Furthermore, when FGSA is applied to Support Vector Machine (SVM) classification, suitable feature subsets and SVM parameters can be effectively found out, and better classification results will be obtained.

As the gravitational search algorithm plays bad performance in search accuracy of the complex issues,especially the poor search quality of standard Gravitational Search Algorithm (GSA) in the high dimensional function optimization. It is easy to get into premature convergence in the optimization process. Therefore, the idea of the particle swarm optimization algorithm was introduced to gravitational search algorithm, which was used to improve the memory of particles. The particle evolution is not only influenced by other particles in the space, but also by its own memory constraint, which is used to improve the ability of exploitation. The test of the 10 benchmark functions confirms the validity of the method.