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• 2011, No. 1　Published:25 January 2011 Last issue    Next issue
  Columns in this issue: 论文

• 论文

  BA-BGP:A New InterDomain Routing Protocol Based on Backup AS Advertisement

  HU Qiaolin,SU Jinshu

  2011, 33(1): 1-6. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 1002 )   PDF (1022KB) ( 526 )   　　

  The BGP routing protocol triggers global and reactive convergence to dynamically adapt to network topology and policy changes, Nevertheless, the long convergence time, transient disconnectivity and forwarding loop during the routing convergence process lead to forwarding disruption, which makes BGP hard to support the critical business applications such as VoIP, interactive telesurgery. In this paper, We present BABGP, a novel interdomain routing protocol based on backup AS advertisement. BABGP does not affect the BGP dynamic behavior, AS node learns the backup AS address associated to destination by adding the Backup AS attribute in the update packets. BABGP provides a feasible encapsulation forwarding path associated backup AS when the AS node experience failure, which reduces the forwarding disruption time. Through a detailed evaluation on the Internet characteristic topology and the widelyused BGP policy, we show that BABGP improves network survivability effectively, and reduces the transient failure and forwarding disruption time in case of link failure.

  An Optimization Method for GSM Network Covering Based on TA

  ZOU Beiji,XIAO Weixiong

  2011, 33(1): 7-11. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 515 )   PDF (612KB) ( 418 )   　　

  With the rapid expansion of the mobile GSM network scale and urban construction, the cell coverage environment is complex and protean, which influences the station signal,and causes the work load and the difficulty of network optimization more difficult. This paper designs and implements a multiunit data collection method to acquire the realtime performance data of the GSM network. In order to improve the efficiency of data processing, it uses a fast incremental update algorithm to process the performance data of the GSM network. By using the Gaussian Distribution and Mahalanobis Distance to analyse the parameter variation of the TA, the upward and downward path loss and the output power, we count abnormal data and the changes of the district coverage environment, then give network optimization advice according to the analysis results. This method implements the cell coverage environment system based on TA which can help network optimization more efficient and improve the efficiency of the GSM network optimization.

  A Maximum Network Lifetime Broadcast Algorithm for Mobile Ad Hoc Networks

  JIAO Xianlong,WANG Xiaodong,ZHOU Xingming

  2011, 33(1): 12-19. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 497 )   PDF (1011KB) ( 379 )   　　

  The network lifetime problem of broadcast for mobile ad hoc networks has always been an interesting and hot research topic.The  existing research has proved that the broadcast algorithm based on the minimum spanning tree can optimally solve the network lifetime problem. However,these research activities are all based on static network topology,which is not suitable for some practical scenarios with changeable network topologies,such as the military communications. Therefore,for these scenarios,this paper proposes a maximum network lifetime broadcast algorithm called LONG for mobile ad hoc networks. This broadcast algorithm is based on motion prediction and the basic idea of the minimum spanning tree algorithm,and is implemented using the Fibonacci heap.A theoretical analysis shows LONG achieves the maximum network lifetime,and its time complexity is O(n2),where  n  denotes the number of nodes in the networks. Finally,the results of the extensive simulation implemented by NS2 show that,the packet delivery ratio and the  network lifetime of LONG are better than those of other broadcast algorithms.

  Research and Implementation of Baseboard Management in InfiniBand Switch

  YIN Jiabin，TONG Xin，SUN Zhigang

  2011, 33(1): 20-24. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 504 )   PDF (538KB) ( 387 )   　　

  As an interconnection technology, InfiniBand is considered as a new solution to eliminate the performance bottleneck of current I/O framework because it owns many advantages of high bandwidth, low delay, etc. InfiniBand subnet implements high speed interconnection and data transmission from tens of nodes to hundreds of nodes. Now, InfiniBand technology is widely used in high performance computing and becomes the first choice for the interconnection in high performance computing.. Baseboard management, an important component of network management, implements hardware management of InfiniBand switch and interface adapter. It's of significance for efficient baseboard management to improve the availability of InfiniBand network. This paper analyzes the model of baseboard management in InfiniBand switch and designs a realization method of baseboard management in IBS216Q switch.

  Design and Implementation of a User Defined Packet Performance Test for AX4000Based Routers

  CHEN Xiaomei，TIAN Yang，WANG Baosheng

  2011, 33(1): 25-30. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 423 )   PDF (715KB) ( 503 )   　　

  The paper presents a method which supports the test of a new network protocol. We design a normal and agility interface for the testers to define and construct the packets of a new protocol, then transform the packets to a  standard protocol type while the system working under the existing condition. The testers do not concern the switching process, and it is transparent. The testers initialize the structure of the packets,construct packets, set up the interface parameters and run the testing process to get the results. Experimentations indicate that the system is more compatibile, flexible and friendly.

  An Algorithm of Network System Reliabiilty Based on an Improved Disjointed Minimal Path Set

  SHI Yufang1,LU Ning2,LI Huimin3

  2011, 33(1): 31-35. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 499 )   PDF (539KB) ( 532 )   　　

  Constructing a disjoint minimal path set is an important approach for the reliability analysis of networks. Based on the disjoint theory and the BDD algorithm, an improved algorithm is presented for directly and simplily constructing disjointed minimal paths in which different disjoint methods are used for the minimal path set with different path lengths. According to the improved algorithm, a program is provided to obtian the disjointed minimal path set of the network system,and network reliability can be effectively worked out.Finally, a numerical example is given. It is shown that the method is efficient and accurate. It provides a new approach for the reliability analysis of largescale network systems.

  Research and Implementation of OffLine  Web Technology in the RIA Environment

  CHENG Guoxiong,HU Shiqing

  2011, 33(1): 36-41. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 507 )   PDF (792KB) ( 358 )   　　

  To improve the Web system performance, Web which works under the offline state is studied. Based on the features of Isolated Storage, the solution of using the Isolated Storage in a Web commercial system is presented. A local smallscale database management component is designed with the Isolated Storage APIs, and the management of the local data storage is solved. Meanwhile, the local data synchronized with the remote data is achieved based on the incremental updating of the data synchronization engine, which uses the TCP socket communications. The socket service is designed to achieve the clientserver time synchronization and push data to the client from the server. The experimental results show that, this system runs well in a low bandwidth or network fault state, and the reliability of the Web systems is improved.

  Application of the Genetic Simulated Annealing Algorithm in Multicast Routing Optimization

  ZHU Dongmei，SHENG Jianling

  2011, 33(1): 42-46. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 434 )   PDF (621KB) ( 322 )   　　

  This paper studies bandwidth delay and the delay variation constrained leastcost QoS multicast routing problem and proposes a genetic simulated annealing algorithm which can speed up the evolutionary rate and avoid antiprecocity. The algorithm adopts tree structure coding and improved cross and variation operations, and combines the merits in the partial search ability of the simulation annealing algorithm. It constructes a neighbor set in the range of feasible solutions and gives a new criterion for judging the premature convergence.The simulation results show that the revised algorithm has a more rapid convergence rate in the global optimal solution than the only genetic algorithm and the simulated annealing algorithm.

  A Pairing Based Mutual Authentication Scheme

  XIANG Wen,LONG Xiaohui,LI Chenghua

  2011, 33(1): 47-50. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 436 )   PDF (551KB) ( 367 )   　　

  A new pairing based mutual authentication scheme using USB Key is proposed. To enhance the security of the authentication system, our proposed scheme using the technique of double private keys can accomplish the registration and the authentication phase separately. The scheme integrates both the advantage of the bilinear map cryptography and the USB Key technology based on security chips. It is resilient to replay, forgery, maninthemiddle attacks and insider attacks.

  An Improved Remote User Authentication Scheme

  WANG Songbo

  2011, 33(1): 51-55. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 357 )   PDF (366KB) ( 374 )   　　

  For some security flaws that lie hidden in the YoonYoo’s user authentication scheme such as masquerading user attack, masquerading server attack and stolen verifier attack, this paper proposes a new remote user authentication scheme using random numbers to repeat hash operations. This scheme resolves all the aforementioned problems, while keeping the merits of YoonYoo’s scheme. Therefore, this scheme has a more stable security, and provides an effective solution of remote user authentication for electronic commerce.

  Research on the Application of Security Algorithms in Wireless Sensor Networks

  ZHANG Ruiqing1,YANG Wenqiang2,ZHANG Juncai2

  2011, 33(1): 56-59. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 398 )   PDF (669KB) ( 307 )   　　

  The energy consumption incurred by security algorithms has negative impact on the lifetime of sensor nodes and the whole network. In order to get a tradeoff between network security and availability, this paper first introduces the related technologies on measuring the energy cost of security algorithms.Then the energy cost of some security algorithms on Crossbow node is measured. It is of benefit to know about the effect of security algorithms on the energy cost of nodes in WSN. In the end some guidelines for application of security algorithms in wireless sensor network are proposed based on the analysis of the measuring results and it is of benefit to the application of security algorithms in WSNs.

  A HP Heterogeneous Multiprocessor Architectural Platform and Its Application

  QUAN Wei,WEN Mei,WU Nan,YANG Qianming,ZHANG Chunyuan

  2011, 33(1): 60-65. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 520 )   PDF (1319KB) ( 430 )   　　

  In the field of video codec, with the improvement of the video’s resolution, the demand of the processing platform’s computingpower, as well as the storage and transmission bandwidth, is required to be increased dramatically. To meet the huge performance requirements of highresolution video codec, this paper,which combines with the unique advantages of stream processors in the media processing and the flexibility of the FPGA, provides a configurable heterogeneous multiprocessor platform. In order to test the ability of the platform, the MOTION JPEG algorithm will be mapped to this platform after being parallelized,and encode the HD digital video with the resolution of 4096×2160 at 30.3 frame/s.

  Performance Analysis and Improvement   of Flash Under Fragmentations

  ZHANG Xiangli，ZHAI Jiandong

  2011, 33(1): 66-69. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 402 )   PDF (504KB) ( 355 )   　　

  Unlike a hard disk, there is no mechanical parts in flash. Therefore, the reason of disk fragmentation weakening the performance of the flash is not seekdelay, but is its own characteristics. Through inducting the Flash Translation Layer(FTL), the existing file system can directly be applied to the flash. At the same time, FTL is the reason of performance degradation of flash under  fragmentations. When there is some fragmentations in flash, the difference of merge operation types result in the performance degradation. On the basicis of  reason analysis,a scheme of padding the spacing is put forward and its validity is demonstrated.

  Integrating Contexts into the Classification of HighResolution Remote Sensing Images Using the Bayesian Networks

  CHENG Huanhuan,WANG Runsheng

  2011, 33(1): 70-76. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 511 )   PDF (975KB) ( 545 )   　　

  In this paper, a Bayesian networkbased context model (RCBN) is presented to classify high resolution remote sensing (HRRS) images. First of all, image regions are classified by SVMs and candidate regions for each ground cover types are obtained. Then, the hybrid streams of candidate regions and spatial context information are piped into the context model, which will produce the category labels of regions by performing inference through the network. The RCBN consists of three kinds of nodes, which are nodes for candidate regions, related regions and contexts. The context nodes vary with different ground cover types, which are learned by the structure learning algorithm from training samples. Therefore, our RCBN model is capable of using the specific context information for each ground cover type, which makes the classification process more intelligent and efficient. The performance of the approach is evaluated qualitatively and quantitatively with comparative experiments, and the results show that the proposed methods are able to automatically classify and detect segments belonging to the same object classes.

  GPUBased Computation and an Implementation Method of Volume Illumination for UnstructuredGrid Data

  MA Qianli,XU Huaxun,YUE Kai,LI Sikun

  2011, 33(1): 82-87. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 523 )   PDF (775KB) ( 397 )   　　

  Gradient estimation is necessary for illumination effects which play an important role in volume rendering. Compared with the structured grids, it is difficult to estimate the vertex gradient for unstructured grids due to the complicated topology. Futhermore,realtime rendering can be hardly achieved due to the computation complexity of the resampled point gradient and the difficultity of implemention on GPUs. As a result, most of the unstructuredgrid volumes have not been lit. This paper presents a method to estimate the vertex gradient with high precision for unstructured grids. It employs the volumeweighted extrapolation and the inversedistance extrapolation to compute a vertex gradient using a group of cell gradients estimated by the Green theorem. Meanwhile, to compute the gradient at a resampled point, we present an efficient method based on the cell divergence which makes the cost much lower than the recent method of fulllinear interpolation。The realtime performance of our algorithm even for the relative large data sets can be achieved by its GPU implementaion with the aid of a welldesigned data structure.

  A New Easy Fast Camera SelfCalibration Technique

  LIU Bixia1,2，LI Shaozi1,3，GUO Feng1,3，SU Songzhi1,3

  2011, 33(1): 88-93. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 457 )   PDF (583KB) ( 420 )   　　

  In this paper, we present a new camera calibration approach by taking three images at least of the proposed planar pattern which includes an arbitrary circle with its inscribed regular triangle under different orientations. First, the imaged circular points are derived from the images of the proposed planar pattern. And then, the camera intrinsic matrix and extrinsic matrix are determined via the obtained imaged circular points. In contrast to the conventional methods, our method avoids ellipse and line fittings. It reduces the computing complexity and it is more robust to noise. Another advantage of our method is that neither any metric measurement on the model plane, nor the point correspondences is necessary; hence the calibration process becomes extremely simple. Experiments on both synthetic data and real image data demonstrate the robustness and effectiveness of our method.

  An Adaptive Voice Activity Detection Algorithm in Noisy Environments

  LIN Xuemei

  2011, 33(1): 94-96. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 386 )   PDF (406KB) ( 573 )   　　

  The shortages of shorttime energy based voice activity detection method is analyzed first. Then a shorttime signaltonoise ratio (SNR) estimation method is introduced, and a new adaptive voice activity detection algorithm is proposed based on the design of the adaptive discriminative threshold. Simulations with a lot of Gaussian noisy speech signals ranging from 10dB to 20dB show that the comparatively accurate speech endpoints can be detected by the proposed method in different SNR environments.

  Design of a Common Face Detection Module Based on OpenCV

  ZHANG Ying，LI Yongping，AO Xinyu

  2011, 33(1): 97-101. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 731 )   PDF (746KB) ( 383 )   　　

  Face detection is an important part in intelligent video surveillance systems. The Adaboost face detection algorithm of OpenCV can process videos in a realtime way. Because of the languages and platforms, very few systems are compatible with such a function. A module of face detection that supports multiple program languages is presented,and the P/Invoke techniques in the .NET and the improved JNI methods for calling the OpenCV face detection module are explained in detail. This module solves the problems of parameter passing among .NET, Java and OpenCV for color images and can be simply integrated into most existing videobased application systems. It also defines a standard interface for module scheduling and can be referenced by more crossplatform applications. The experimental results show that the video systems which integrate this module obtain a high detection rate and realtime processing speed with limited system resources.

  A NonSymmetry AntiPacking Pattern Representation Model Based on MultiPatterns

  WAN Lin1，HU Weijun2，LU Yongliang2

  2011, 33(1): 102-106. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 386 )   PDF (523KB) ( 293 )   　　

  The multipatternsbased nonsymmetry antipacking pattern representation model is a nondestructive image expression method. This paper focuses on the typical model of points, straight lines, rectangles and triangles and presents an image representation method based on multipatterns. And the typical triangular pattern includes four directionel nonrightangled isosceles triangles. In this paper, we induce the basic idea of MNAM,analyse the structure of data storage,and give the encoding and decoding algorithms and the algorithm complexity. The results show that the image which uses MNAM has very good performance in the compression ratio and the reconstruction image quality.

  A HighCapacity Airspace Hiding AlgorithmBased on Visionremains Characteristics

  CHEN Guiyun1,2,ZHANG Dafang2,LIU Jiancong1

  2011, 33(1): 107-111. doi: 10.3969/j.issn.1007130X.2011.

  Abstract ( 414 )   PDF (958KB) ( 391 )   　　

  According to the characteristics that different gray eyes,have different sensitivities.We design an embedding algorithm which is adaptive to the characteristics. Experiments show that the image visual effect generated by the algorithm is better than that of the congener algorithms.