This paper proposes a hierarchical IPv6 real-name address space as network identity. It builds an IPv6 real-name address resource PKI according to current IP address allocation structure for allocation, management and authentication work. It designs and implements a trustworthy communication system supported by third party’s IPv6 real-name address resource PKI. Experimental result shows that the mechanism can achieve the goal of real-name communication and privacy protection.
In order to realize the performance evaluation for Extensible Markup Language(XML) database, this paper presents a XML database test scheme based on TPC-C test benchmark. Aiming at the trait of XML database, it specializes in data structure and query event sentence. The original nine tables are mapped to five new XML Schema documents, it rewrites the workload according to the SQL/XML standard and uses the scheme for testing a SQL Server 2005 database. Results show that the characteristics of various affairs equal to TPC-C test benchmark.
n order to compute semantic relevancy for the specific domain knowledge in opinion mining, this paper proposes a semantic relevancy computing method based on Wikipedia. On the basis of constructing a category tree from Wikipedia, it represents the vast words in Wikipedia by using the category and the result in a Wikipedia dictionary which contains rich domain-specific knowledge, and then computes semantic relevancy by using the dictionary. Experimental results show Spearman rank correlation coefficient of this method can reach 0.77.
Aiming at the problem of presented algorithms inefficient extract spatial topology association, this paper proposes a mining algorithm of alternately search spatial topology association, which is suitable for mining spatial topology association rules in large data. From two endpoints of candidate digit interval, the algorithm uses two methods of generating candidate frequent itemsets in digit ascending and digit descending, in order to alternately search spatial topology association rules. The algorithm also uses digit feature to reduce the number of scanned transaction when computing support of itemsets, mining efficiency is improved. Experimental result shows that the algorithm is faster and more efficient than presented algorithms when mining spatial topology association rules in spatial data.
Timely firing of Link-Going-Down(LGD) trigger is critical to handover performance and is significant in determining whether the handover completes successfully. This paper proposes the terminal moving state-based LGD trigger algorithm. It calculates the received signal power from the terminal moving model, and puts it as part of the predictive process. Simulation results show that the proposed algorithm can significantly decrease packet lost and the time between handover finishing and link down.
Opportunistic routing protocol adopts routing-delayed mechanism. The mechanism is a subversion of the traditional routing. This paper designs an opportunistic routing protocol that can adapt to volatility of wireless channel and realizes the protocol on Linux platform as a kernel loadable module. The preliminary results show that opportunistic routing protocol can improve packet delivery and decrease time delay greatly. Most importantly, the mechanism is almost unaffected by the changing wireless channel and can adapt to its instability and unpredictability better.
This paper designs and implements a high-precision network emulator based on protocol filtering by employing network driver interface specification technology based on Windows platform. The emulator is capable of emulating various kinds of the network transmission conditions of WAN links in real-time, including network bandwidth, packet loss, transmission delay, and out-of-order transmission. Experimental results indicate that the network emulator achieves high-precision, low-load design requirements. Realization of the emulator can help to study the QoS of multi-media network applications, analyze network protocol, and verify network control algorithms.
Aiming at the bottleneck of SVM that the speed of classification depends on the number of support vectors, this paper proposes a fast classification algorithm for SVM. In feature space it constructs the minimum spanning by introducing the similarity measure and divides the support vectors into groups according to the maximum similarity. The determinant factor and the adjusting factor are found in each group by some rules. In order to simplify the support vectors, it takes the linear combination of determinant factor and adjusting factor to fit the weighted sums of support vectors in feature space, so that the speed of classification is improved. Experimental results show that the algorithm can get higher reduction rate of classification time by minor loss of classification accuracy and it can satisfy the requirements of real-time classification.
Aiming at the problem that Direct Current(DC) coefficient and Alternating Current(AC) coefficient express different image content information, this paper presents a JPEG image retrieval algorithm based on DCT coefficient. The difference vector of DC coefficient is constructed to describe image feature. The AC coefficient distribution entropy is presented according to the characteristic of the AC coefficients. The weight function for the entropy is presented to avoid the mistaken retrieval and losing retrieval. Experimental results show that the algorithm has no use for decompression and has lower complexity, and it can embody the content distribution of images well.
With respect to the requirement of high speed communication between two kinds of fabric in a high performance embedded system, this paper proposes a hardware method for RapidIO-FC switching bridge on FPGA. This method builds commutator control logic and bridge interface with RapidIO and Fibre Channel(FC) IP core based on the development platform of Xilinx Virtex5. The function of the bridge is validated. Hardware architecture diagrams and the key design thoughts are alse introduced. The method is proved valid by logic simulations and physical tests.