Aiming at the problem of high cost and long time consumption of updating the electronic map in navigation system, a new road judgment and electron map updating algorithm based on failure data screening was proposed, which utilized the circumstances of unsuccessful matching between the history GPS track of floating vehicle and the current electronic map. First of all, the main direction of the travel path was judged by calculating the horizontal and vertical spans of all the failure points. Secondly, elegant point screening was used to cull the misregistration groups of data points due to the malfunction of the on-board GPS equipment; then the linear least square method was used for the linear fitting of failure-matching abnormal trajectory to determine the position and direction of the track; the positioning data point groups with large error were culled by angle screening. Finally, the screened trajectory data was fused and ordered by the main direction. Combined with the road network structure of electronic map, the new road was inserted into the current road network according to the matching results of the endpoints of the new road. Experiments were conducted on the electronic map of a local area network of some city. Experimental results show that the method can accurately determine and screen the new road, and rightly insert the new road into the current network structure of the electronic map.

Collaborative filtering algorithm is the most widely used algorithm in personalized recommendation system. Focusing on the problem of date sparseness and poor scalability, a new clustering recommendation algorithm based on user interest and social trust was proposed. Firstly, according to user rating information, the algorithm divided users into different categories by clustering technology, and set up a user neighbor set based on interest. In order to improve the accuracy of the calculation of interest similarity, the modified cosine formula was used to eliminate the difference of user scoring criteria. Then, the trust mechanism is introduced to measure implicit trust value among users by defining the direct trust calculation method and indirect trust calculation method, converted a social network to a trust network, and set up a user neighbor set based on trust. Finally, this algorithm combined the predictive value of two neighbor sets to generate recommendations for users by weighting method. The simulation experiment was carried out to test the performance on Douban dataset, found suitable value of α and k. Compared with collaborative filtering algorithm based on users and recommendation algorithm based on trust, the Mean Absolute Error (MAE) decreased by 6.7%, precision, recall and F1 increased by 25%,40% and 37%. The proposed algorithm can effectively improve the quality of recommendation system.

This paper presented a new self-adaptive image encryption algorithm so as to improve its robustness. Under this algorithm, a gray image or color image was divided into 2×2 size blocks. A corresponding size of matrix in the top right corner was created by the pixel gray-scale value of the top left corner under Chebyshev mapping. The gray-scale value of the top right corner block was then replaced by the matrix created before. The remaining blocks were encrypted in the same manner in clockwise until the top left corner block was finally encrypted. This algorithm is not restricted to the size of image and it is suitable to gray images and color images, which leads to better robustness. Meanwhile, the introduction of gray-scale value diffusion system equips this algorithm with powerful function of diffusion and disturbance.

 A matching algorithm based on the negative selection for anomaly detection was presented in this paper. In the algorithm the effects of position between two temporal sequence to matching degree were considered. So it could distinguish accurately self and non-self, and reduced the size of detective set effectively. Using normal sequence calls, the initial detective set was created, and the detective set was extended by learning, according to the proportion of anomaly temporal sequence to judge whether this sequence was anomaly. Finally, the results of experiment was given.