Advanced Materials Research Vols. 756-759

Abstract: To solve the university timetabling problem (UTP) effectively, a immune algorithm-based solution for UTP was proposed. The mathematical model of UTP was expounded, a framework of immune algorithm was given, and simulation experiments were done to validate algorithm. Experimental result shows that proposed algorithm can solve the UTP effectively, and has the advantage of good application value.

Abstract: Wireless sensor node's localization is a funda-mental technology in Wireless Sensor Networks. There are only quite a few study on three-dimensional (3D) localization which is suffered in slow progress, actually, is one of the main difficulties in WSN localization. Based on the study of the existing two-dimensional positioning algorithm and the application of terrain modeling, localization algorithm for sensor nodes in (3D) condition has been focus on as well as the application of terrain model. Using the idea proposed by representative algorithm--APS multi-hop AOA (Angle of Arrival), this paper proposed a new algorithm named Multi-hop Three Dimensional AOA With Space-based Angle Trans-mission (MSAT3D AOA). Using this technology, target nodes can use information of anchor nodes which are more than one hop away form. This paper also combined MSAT3D AOA algorithm with Delaunay triangulation algorithm for terrain modeling.

Abstract: Machine learning uses experience to improve its performance. Using Machine Learing, to locate the nodes in wireless sensor network. The basic idea is that: the network area is divided into several equal portions of small grids, each gird represents a certain class of Machine Learning algorithm. After Machine Learning algorithm has learnt the parameters using the known beacon nodes, it can classify the unknown nodes location classes, and further determine their coordinates. For the SVM OneAgainstOne Location Algorithm, the results of simulation show that it has a high localization accuracy and a better tolerance for the ranging error, while it doesnt require a high beacon node ratio. For the SVM Decision Tree Location Algorithm, the results show that this algorithm is not affected seriously by coverage holes, it is suitable for the network environment of nonuniformity distribution or existing coverage holes.

Abstract: The data synchronous of the distributed heterogeneous database was one of the important researches for the heterogeneous databases. This paper analyzed the data synchronization optimization mechanism of the distributed heterogeneous database and puts forward to get the minimum change data set from each node database and then get the system total change data set, and then find out each node database of minimal update data set to update each node database, so as to realize the synchronization of heterogeneous database.

Abstract: An optimized fast fixed point algorithm based on modified Newton iteration method has been proposed. With good performance ofthe blind image separation, the optimized algorithm can improve the convergence speed greatly.We proposed a new adaptive enhancement parameter to enhance the separated images effectively. The experimental results demonstrate that the new algorithm is superior.

Abstract: As an extremely important platform of data storage, database management system (DBMS) is widely used in all kinds of enterprises and departments. The availability and security is a critical performance index for database. How to help administrator keep database secure and effective is a key job of database administration. This paper proposes a secure model of database management for administrator and achieved a secure database console to implement this model.

Abstract: Aiming at solving the problems of occlusion and illumination in face recognition, a new method of face recognition based on Kernel Principal Components Analysis (KPCA) and Collaborative Representation Classifier (CRC) is developed. The KPCA can obtain effective discriminative information and reduce the feature dimensions by extracting faces nonlinear structures features, the decisive factor. Considering the collaboration among the samples, the CRC which synthetically consider the relationship among samples is used. Experimental results demonstrate that the algorithm obtains good recognition rates and also improves the efficiency. The KCRC algorithm can effectively solve the problem of illumination and occlusion in face recognition.

Abstract: Kernel methods can effectively deal with the nonlinear problem. The methods not only can be used for data de-noising, also be effective for classification problems. Using kernel PCA method, we provide a more precise Zernike expansion, which can apparently improve the reconstruction accuracy. At the same time, explore learning the kernel function by the alignment. We verify that the alignment value and recognition rate is proportional relationship.

Abstract: Frequency offset brings a great impact on communication, a small amount of which may cause a serious decline in the performance of communication system. So frequency offset estimation has great significance. TD-LTE system is very sensitive to the frequency offset, we propose a method to estimate the integer frequency offset through calculating spectrum centroid. Simulation results show that the algorithm has a good performance and lower complexity compared with some integer frequency offset estimation algorithms based on data-aided.

Abstract: Cognitive radio is one kind of wireless communication technology, which is to effectively improve the spectrum efficiency by the way of wireless spectrum sensing. Besides of varieties of security issues of the traditional wireless communication, it also has some new problems, such as Primary User Emulation (PUE) attack. This essay presents that based on the fractal dimension of the transient signal characteristics extraction to protect the PUE attack from the cognitive wireless networks, and then extract the fractal dimension of wireless transmitter through experiments to provide reliable characteristic parameters for the next signal recognition, finally to prevent PUEs attack.