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• 2016, No. 11　Published:25 November 2016 Last issue    Next issue
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• A scheduling policy of scientific workflows allowing

  the violation of local time constraints

  CHEN Wanghu，DUAN Ju,YU Maoyi

  2016, 38(11): 2165-2171. doi:

  Abstract ( 149 )   PDF (516KB) ( 438 )   　　

  Improving the execution efficiency as well as reducing the execution cost of the scientific workflows in cloud is important. Focused on the conflict between userdesired local QoS constraints and the overall execution efficiency of the workflow，we propose a scheduling policy of scientific workflows allowing the violation of local time constraints. Based on backward merging of task clusters, free time spans between workflow task executions can be exploited, and the whole execution time of the workflow can be optimized. Furthermore，in order to make full use of the slack time during task execution and improve the overall efficiency of the workflow, some workflow tasks are permitted to violate the local constraint of the latest finish time. Experimental results show that the policy can bring forward the earliest finish time of the workflow and improve the utilization ratio of processors, and eventually lower the execution cost of the workflow.

   

  A loadbalancing algorithm based on LVS cluster in cloud

  WANG Xiaolong，JIANG Chaohui

  2016, 38(11): 2172-2176. doi:

  Abstract ( 176 )   PDF (659KB) ( 422 )   　　

  In order to deal with the new issue caused by the application of traditional load balancing techniques in the cloud computing environment, we propose a loadbalancing algorithm based on LVS cluster. Firstly, we calculate the weight of each node and divide the servers into different groups, in which their performance should be equal (or approximately equal). The number of nodes in each group should also be equal (or approximately equal). The load balancer regularly collects the data of CPU, memory, I/O, network utilization and response time of each node in the cluster, and dynamically alters the weight of nodes, and selects the best node in this group by using the improved algorithm. At the same time, the comprehensive load of each node and the group load are calculated. Finally, we select the best node of the cluster and carry out the rational distribution of task requests via the group load balancer (GLB), to solve the delay caused by too many concurrent requests in the cloud computing environment. Experimental results show that compared with the weighted round Robin (WRR) and weighted least connections (WLC), the proposed algorithm can concurrently maintain a shorter response time and a higher throughput, which makes the cluster system load balanced.

  Parallel optimization of target tracking algorithms

  CHEN Wei1，ZHU En1，LIU Tianhang1，YIN Jianping1，QIU Minghui2

  2016, 38(11): 2177-2182. doi:

  Abstract ( 167 )   PDF (458KB) ( 348 )   　　 Review attachment

  Object tracking is an important research area in computer vision. Researchers have proposed a number of excellent object tracking algorithms in recent years. However, the poor realtime performance of these algorithms restricts its effectiveness in application scenarios. Based on these algorithms, we design a general tracking model and propose a feasible parallel optimization scheme for the model. We also use the sparsitybased collaborative model (SCM) algorithm to validate the proposed scheme. In a fourcore CPU environment, the parallel algorithm achieves a speedup of 3.48 times compared with the sequential algorithm, and it is about 30 times faster than the MATLAB+C program of the original algorithms, thus verifying the effectiveness of the proposed parallel optimization scheme.

  Two data compression methods for recommender systems

  LIU Bo1，LIU Xiaoguang1，WANG Gang1，WU Di2

  2016, 38(11): 2183-2190. doi:

  Abstract ( 164 )   PDF (969KB) ( 347 )   　　 Review attachment

  There is an enormous number of training data being generated in Headlines Today's sever. These data is formatted for Machine Learning. We observed that whichever common data compression method cannot perfectly satisfy business requirements: a better compression ratio. We present two methods for training data from Headlines Today’s sever. One is called hierarchical cluster compression (HCC), and the other is hash recoding compression (HRC). The HCC with Gzip Compression can quadruple the compression speed than pure Gzip Compression, which indicates that the first  proposed method can effectively promote compression speed and guarantee the compression ratio as well; the HRC with Snappy Compression is able to halve the compression ratio in comparison with pure Snappy Compression, which shows that the HRC can reduce the compression ratio and lower the compression speed as little as possible. Above all, it is meaningful to choose whichever method for decreasing operation costs, promoting business processes efficiency and providing better user experience.

  A wearable data redissemination method

  based on Kanonymity clustering

  LI Tong,LIU Qiang,CAI Zhiping,ZHOU Tongqing

  2016, 38(11): 2191-2196. doi:

  Abstract ( 140 )   PDF (526KB) ( 355 )   　　 Review attachment

  Nowadays, wearable devices are widespread in our daily life. The rapid growth of users' number results in data redissemination by data holders. Nevertheless, improper redissemination methods can lead to unacceptable information loss or privacy leakage. In addition to privacy preserving concern, the data republishing methods for wearable devices should also be efficient enough due to the rapid increase of the number of wearable devices. In order to enhance the efficiency under the premise of information security of users and acceptable information loss, we propose a wearable data redissemination method based on clustering Kanonymity. The proposed method jointly considers data privacy, information loss and the overheads. Specifically, the proposed method processes the incremental data directly to enhance the efficiency and the clustering Kanonymity can limit information loss. The proposed method can reduce information loss when the amount of the data is huge. Experimental results demonstrate its effectiveness.

  An independent variable exclusively

  coupled chaotic pseudorandom bit generator

  WU Qi

  2016, 38(11): 2197-2201. doi:

  Abstract ( 111 )   PDF (568KB) ( 285 )   　　 Review attachment

  We design a new way of coupling, namely, an independent variable exclusive coupling, which is applied to skew tent mapping to obtain a new chaotic system. Experiments demonstrate that the system possesses excellent chaotic properties. A pseudorandom bit generator is then constructed based on it, and we employ five statistic tests to evaluate the pseudorandomness of the bit streams generated by the proposed generator. We finally compute the linear complexity of the generated bit streams and the cipher space of the generator. All the experiments illustrate that the generator holds satisfactory properties and is suitable for applications in information security.

  A packet transmission mechanism based on hybrid

  social groups in mobile opportunistic networks

  CHEN Weimin1，2，CHEN Zhigang2,CUI Fang2，LIU Jiaqi2

  2016, 38(11): 2202-2208. doi:

  Abstract ( 135 )   PDF (625KB) ( 356 )   　　 Review attachment

  Mobile opportunistic networks which are formed by humancarried intelligent devices, implement the packet transmission between nodes by taking advantages of the relay forwarding based on the “storecarryforward” principle of communication. In order to improve the network performance, the social attributes of nodes are often used to select the relay and make data forwarding decisions. However, the existing packet transmission mechanisms usually use partial social attributes of nodes therefore the social relationship between the nodes cannot be fully reflected. We propose a new packet transmission mechanism based on hybrid social groups in mobile opportunistic networks. We define the concept of hybrid social group, provide the construction method of hybrid social groups and design a packet transmission algorithm. Experiments on several real data sets demonstrate that the proposed mechanism has a higher transmission success rate, a shorter transmission delay and a better performance in comparison with the existing socialgroup routing schemes.

  Analysis and application of the high performance data

  packet capture technology based on dpdk

  ZHAO Ning1,XIE Shucui2

  2016, 38(11): 2209-2215. doi:

  Abstract ( 313 )   PDF (873KB) ( 400 )   　　 Review attachment

  We analyze the data packet capture technology based on intel dpdk in depth, point out in detail the advantages and disadvantages of dpdk in current development of packet capture technology. We then design and implement a packet capture system based on Linux by dpdk, and apply it to a gigabit network security protection system successfully. Utilizing the BPS software, we simulate our system and the network security protection system based on pf_ring. Simulation results show that dpdk can improve the overall system performance, achieve good effect, thus  verifying the feasibility of the proposed method.

  Performance analysis of MVDR algorithm in

  GPS deception jamming environment

  DONG Hui，HAO Pengfei，WANG Chun，ZHANG Lu

  2016, 38(11): 2216-2220. doi:

  Abstract ( 137 )   PDF (563KB) ( 342 )   　　 Review attachment

  The classical minimum variance distortionless response (MVDR) algorithm has an excellent performance in the GPS blanket jamming environment. To analyze the performance of the classical MVDR algorithm in deception jamming environment, we derive an approximate expression of the array gain and output signaltointerferenceplusnoise ratio according to the fact that desired signal power and interference power are far below noise power. Combined with the simulation results, we figure out the reason why the MVDR algorithm loses the ability of interference suppression in the deception jamming environment. In addition, we also discuss the factors that impact the output signaltointerferenceplusnoise ratio and the way they work.

  An anonymous method for Chinese library

  classification encoding in digital library

  JIA Junjie,CHEN Fei,YAN Guolei,XING Licheng

  2016, 38(11): 2221-2226. doi:

  Abstract ( 141 )   PDF (554KB) ( 361 )   　　 Review attachment

  Now most of the data published in digital library is of  book resources, however, data with user attributes and library resources is rarely published. The analysts therefore cannot obtain much information from existing released data, which causes problems for some scientific research. We propose an anonymous method which publishes user attributes and book information together. We first recode all books using Chinese library classification numbers, divide the whole data according to the sparse conditions of recoding,  and use the substitution method to anonymously encode in each partition. Experimental results show that the final data has higher accuracy and practicability, and that it is able to directly identify the relationship between attributes via the scatter plot, thus providing more useful information for scientific research.

  An efficient and secure image encryption

  algorithm based on quantum chaotic mapping

  LIU Hui，JIN Cong

  2016, 38(11): 2227-2233. doi:

  Abstract ( 146 )   PDF (1702KB) ( 414 )   　　 Review attachment

  We propose an image encryption algorithm based on general twodimensional Arnold transform with keys and quantum chaotic mapping. Firstly, we generate the initial conditions and parameters via the twodimensional logistic mapping. Secondly, we exploit the general Arnold scrambling algorithm with keys to permute the pixels of color components R, G and B. Finally a serial of pseudorandom numbers generated by the quantum chaotic mapping is applied to modify the value of diffused pixels. In order to get the high randomness and the high complexity, the twodimensional logistic mapping and quantum chaotic mapping  are coupled with nearestneighboring coupledmapping lattices.

  Kernel privilege escalation attacks on Linux

  ZUO Yudan,DING Yan,WEI Lifeng

  2016, 38(11): 2234-2239. doi:

  Abstract ( 323 )   PDF (638KB) ( 405 )   　　 Review attachment

  Privilege escalation attack is an important attack against the Linux. According to the types of exploited vulnerabilities, privilege escalation attacks can be classified into two categories: applicationlevel privilege escalation attack and kernel privilege escalation attack. Basic applicationlevel privilege escalation attacks can be prevented by the existing defense techniques, however, they cannot prevent kernel privilege escalation attacks fully. Kernel privilege escalation attacks are still one of the serious threats. We analyze the basic principles for exploiting kernel vulnerabilities and privilege escalation methods for kernel privilege escalation attacks, as well as some typical defense techniques. We analyze and verify the defense effects of the SELinux against kernel privilege escalation attacks, and point out future feasible research directions.

  A generic construction of proxy cryptosystem 

  based on time segmentation

  ZHENG Zhiwei，HUANG Zhenjie

  2016, 38(11): 2240-2245. doi:

  Abstract ( 114 )   PDF (386KB) ( 297 )   　　 Review attachment

  Proxy cryptosystem based on time segmentation (PCBTS) is a typical proxy cryptosystem, which can delegate decryption right to the proxy decryptor, thus alleviating the burden of the original decryptor. Although it has broad application prospects, related research results are not plentiful. Identitybased encryption (IBE) applies the user’s identity directly as a public key, thus the management of the public key certificate is simplified. It therefore has attracted many researchers to put forward a large number of schemes in recent years. According to the differences and similarities between the PCBTS and the IBE in the aspects of algorithm structure and security model, we propose a generic construction method for the PCBTS with a proof of its security. Using the proposed method, any secure IBE scheme can be transformed into a secure PCBTS. We apply this method to an actual case and obtain a secure PCBTS in the standard model, which greatly enriches the quantity and type of PCBTS.

   

  Cryptanalysis and improvement of

  some signcryption schemes

  ZHOU Caixue

  2016, 38(11): 2246-2253. doi:

  Abstract ( 31 )   PDF (445KB) ( 175 )   　　 Review attachment

  We analyze six signcryption schemes and find confidentiality problem in all of them and unforgeability problem in two of them. Then some concrete attacks are presented for these problems. We improve the six schemes using the following methods: binding the sender in the encryption part, binding the receiver in the signature part, verifying equation without plaintext information and binding public key when producing partial private key. These improved schemes are verified in the random oracle model, and security analysis shows that these improved schemes are secure. Finally we point out that some principles must be paid attention to when designing  signcryption schemes.

  Analysis and validation of the brittleness

  of software architecture

  ZHANG Hong，WANG Xiaojun

  2016, 38(11): 2254-2260. doi:

  Abstract ( 110 )   PDF (666KB) ( 290 )   　　 Review attachment

  Software systems can be treated as complex systems because of the features such as numerous nodes, complicated relationships among the nodes, evolving with time and selforganized criticality. In the field of software security, the analysis of software architecture always plays an important role. The software architecture has its own brittleness which reflects in the cascading failure and collapse of the whole software system during its running. We treat the software system as a complex system for the first time, and analyze the brittleness of the software architecture. Then the max collapse path and the brittleness source regarding the “data abstraction and objectoriented” software architecture style are given through the ant colony algorithm and the GROD algorithm, which can have profound implications for the design and monitoring of the software system both in theory and practice.

  Module and conservative extension

  of ontology knowledge base

  YU Quan1,2,CHANG Liang2,WEN Ximing3,WANG Ju2

  2016, 38(11): 2261-2267. doi:

  Abstract ( 106 )   PDF (444KB) ( 316 )   　　 Review attachment

  Modularization is a software engineering method, and it has been introduced into the domain of ontology in recent years to support ontology reuse  and ontology integration. The existing work does not discuss the modularization problem of ontology knowledge base which includes TBox and ABox at the same time. Based on the definitions of ontology knowledge base module and conservative extension, we propose a verification algorithm for the conservative extension of knowledge base, and theoretically prove that it can be used to verifiy whether an ontology knowledge base is a module of another knowledge base.

   

  An accumulated error analysis and a reduction

  method for panoramic mosaic images

   

  WU Qiong,LI Liangfu,WANG Zhitao,XIAO Zhangshu

  2016, 38(11): 2268-2274. doi:

  Abstract ( 128 )   PDF (733KB) ( 368 )   　　

  In order to solve the problem of the accumulated error in panoramic mosaic images, we propose a reference image transformation strategy based on multiple cylindrical projections. Firstly, we improve the cylindrical projection algorithm by combining the phase correlation and the multiresolution decomposition to effectively distribute the accumulated error of the adjacent image and reduce the amount of computation in the cylindrical projection transformation. Secondly, we adopt the strategy of hierarchical matching based on reference image transformation to perform image sequence mosaic, which can avoid unidirectional error accumulation in the mosaic. Finally, we utilize the Laplacian operator to carry out step fusion, which generates highquality results and renders a seamless output panorama. Experimental results show that the proposed strategy can greatly reduce the impact of accumulated error in the process of mosaic and improve mosaic precision.

  A face recognition algorithm  based on QR

  decomposition and reconstruction of virtual samples 

  GUO Yanjun，XU Daoyun，QIN Yongbin

  2016, 38(11): 2275-2281. doi:

  Abstract ( 146 )   PDF (913KB) ( 372 )   　　 Review attachment

  The small sample problem has been a major challenge for face recognition applications for a long time. Concerning the insufficient sample problem in the face recognition process, we propose a face recognition algorithm based on QR decomposition and reconstruction of virtual training samples. We use partial Q and R information to construct virtual samples which have certain difference from the original face image, thus more effective characteristics of the face image that likely change with emotions and illumination are increased, and the training sample sets are expanded. Then we perform weighting fusion on the collaborative representations of the original samples and virtual samples, select the optimal weight combination, adjust the proportions of the original sample and virtual sample which can impact on the results, and obtain the correct recognition rate. Experiments on the ORL, FERET and AR face data sets show that the proposed algorithm can achieve a higher recognition accuracy.

   

  SRC optimal discriminant projection and

  its application in face recognition

  GAN Yanling,JIN Cong

  2016, 38(11): 2282-2288. doi:

  Abstract ( 118 )   PDF (734KB) ( 340 )   　　 Review attachment

  We propose a SRC optimal discriminant projection method according to the classification criteria of the sparse representation classifier (SRC). There are two optimized goals: one is the sparse reconstruction residual betweenclass and withinclass of the data set, the other is the distinction of samples in the data set, which can achieve a higher classification accuracy of the SRC when the samples are projected into a low dimension space. Face recognition experiments conducted on the AR and Yale databases show that the proposed method is more effective and robust in comparison with several other popular methods.

  Dynamically updating projection via low rank

  representation for online moving objects detection

  YANG Guoliang,FENG Yiqin,TANG Jun,XIE Naijun

  2016, 38(11): 2289-2296. doi:

  Abstract ( 105 )   PDF (1088KB) ( 291 )   　　

  Moving objects detection for video processing,which focuses on dividing video images into foreground and background,is important in computer vision.We analyze several traditional moving detection methods,and propose a dynamically updating projection method for online moving objects detection.The proposed method uses the low rank representation (LRR) method to obtain the low rank part of several continuous video images,and thus the projection can be constructed with orthogonal complement of the left singular matrix from the obtained low rank part.The sparse foreground can be obtained by solving the projection model.Besides,the video can be divided into several uniformlyspaced parts,based on which the projection can be dynamically updated.Experimental results on several video databases such as the Curtain demonstrate that our method has better detection performance than the other methods,and it has strong robustness especially when dealing with dynamic background and complex foreground.