The construction of binary Locally Repairable Code (LRC) achieving C-M (Cadambe-Mazumdar) bound has been fully studied while there are few researches on general fields. In order to solve the problem, the construction of LRC on general fields was studied. Firstly, a method for determining the number of elements in sunflower was proposed by projective geometry theory. Then, the parameters such as code length, dimension and locality of LRC were clearly described by depicting LRC through the disjoint repair group. Finally, based on the parity-check matrix with disjoint local repair group, two families of LRC on general fields with the minimum distance of 6 were constructed by sunflower, many of which were optimal or almost optimal. Compared with the existing LRC constructed by methods such as subfield subcode, generalized concatenated code and algebraic curve, the constructed two families of codes improve the information rate under the same code minimum distance and locality. These results can be applied to the construction of other LRC on general fields.

The routing scheme is one of the key factors which influence the lifetime of Wireless Sensor Network (WSN). The network can be paralyzed easily as a result of large energy consumption of key nodes by heavy communication. To solve the problem of energy consumption of key nodes in WSNs, a new ant colony routing algorithm on Dynamic Adjustment of Forward Angle based on Residual Energy (DAFARE) was proposed. Firstly, the nodes chose the next-hop node according to residual energy and distance in the range of initial forward angle; secondly, the forward angle was adjusted dynamically in the view of residual energy of nodes within the scope of forward angle; finally, early death of key nodes was avoided successfully. The simulation suggested that the effective life could be improved approximately 50% by DAFARE, compared with ant colony optimization algorithm based on Function of Multi-object Evaluation and Positive-Negative Feedback (FMEPNF). The experimental results show that, the network energy consumption of DAFARE can be balanced effectively, the lifetime is prolonged, and the coverage of WSN is guaranteed.

To solve the sensor node localization problem of Wireless Sensor and Actor Network (WSAN), a range-based localization algorithm with virtual force in WSAN was proposed in this paper, in which mobile actor nodes were used instead of Wireless Sensor Network (WSN) anchors for localization algorithm, and Time Of Arrival (TOA) was combined with virtual force. In this algorithm, the actor nodes were driven under the action of virtual force and made themself move close to the sensor node which sent location request, and node localization was completed by the calculation of the distance between nodes according to the signal transmission time. The simulation results show that the localization success rate of the proposed algorithm can be improved by 20% and the average localization time and cost are less than the traditional TOA algorithm. It can apply to real-time field with small number of actor nodes.

In order to solve the problem of low and non-uniform resolution in catadioptric omnidirectional imaging, a new image fusion method based on wavelet multi-scale decomposition was proposed in this paper according to the characteristics of complementary panoramic images. Using wavelet transform, the two complementary source images were decomposed into components with different resolutions and different directions first. And then based on specific fusion rules, low frequency was fused by average operator. With high frequency fusion, the exchanging by scales principle was utilized. At last, the fused image was reconstructed by inverse wavelet transform. The experimental results show that the fusion algorithm is simple and effective in the fusion of complementary panoramic images, and has good fusion results.

Concerning the MPC8247 target system based on PowerPC, the device tree was discussed and an embedded Linux system was developed, including the transplant and deployment of U-Boot, Linux kernel, Device Tree Blob (DTB) and Ramdisk file system. The actual operation of the system shows that the device tree file is correct, and the system design is rational and efficient.

Through analyzing the advantages and disadvantages of traditional immersive display systems, a new immersive display system was designed and implemented. In this system, the light illuminated by one projector was reflected by a cylindrical reflector to a cambered rear projection screen. Seamless projection picture can be obtained and coherent displaying of wideangle virtual scene could be implemented. By properly designing the surface of cylindrical reflector, it implemented uniform enlargement of the image on the horizontal direction. The distortion of the projection picture caused by the curvature of the screen could be basically removed through prior distortion of projected image and participants could acquire more moving freedom by means of rear projection. This system overcame the problem of image mosaics in traditional multiprojector and multidisplay immersive display systems. It is simple for manufacturing and can achieve satisfying immersive display quality, which is verified by the experimental result.

Clustering is a complex issue. Although there is a variety of clustering methods, many shortcomings still exist, such as slow clustering convergence, unsatisfactory clustering results, requiring certain parameters provided by people. To solve these problems, a new idea of clustering was put forward. Firstly, the authors supposed each cluster had a cluster center. Secondly, each sample point was considered as an energy source, eradiating energy to the clustering space with a reasonable physical or mathematical diffusing model. Cluster center was confirmed by the total energy that each point gained. Finally, as a result, sample points could be easily clustered to their cluster centers. The experimental results demonstrate that this clustering approach has the characteristics of fast convergence, strong extendibility, and being suitable for natural clustering. Additionally, it can obtain the same results of many classic clustering methods.

A method was proposed for estimating building heights via registering catadioptric omni-directional image and remote sensing image, which can be applied to large-scale 3D city reconstruction. Firstly, the top edges of building roof were extracted from the catadioptric omni-directional image by using omnidirectional Hough transform. Then the catadioptric omni-directional image and the remote sensing image were registered based on the extracted top edges where the angle consistency nature of horizontal lines in catadioptric omni-directional imaging was used as evidence. Finally, according to the model of catadioptric omnidirectional camera, the building heights were estimated by using the registration results. The proposed method is simple and easy to implement. The experimental results show that the method is effective and the error of estimated building height is fairly small.