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  • 中国计算机学会会刊
  • 中国科技核心期刊
  • 中文核心期刊

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    • 论文
      Improved dynamic loadbalancing strategy
      of web servers in virtual environment  
      LIU Shengnan1,WANG Shilin2
      2015, 37(09): 1607-1613. doi:
      Abstract ( 426 )   PDF (760KB) ( 27325 )     

      In order to improve the scalability and automation of web cluster servers, we study many cluster systems from the aspects of virtualization and load balancing, propose a load information collection algorithm based on the Xen server virtualization platform, design and implement a modeling system called XCluster which can automatically control the cluster scale according to the load status. A monitoring service in the new model collects and quantifies the loads of the hosts and active nodes in real time. VM controllers will be notified to deploy more VMs from an optimumload host when lightload nodes are in short supply; however, when there are too many lightload nodes, a number of VMs will be shutdown to release more hardware resources. Theoretical analysis and experimental results show that the XCluster can make full use of the unique capabilities of the virtualization platform which can manage all backend nodes in an economical way. By scheduling VMs, the clusters can avoid resource waste, yet maintaining the applications quality of service within an acceptable size.

      Short-range force algorithm optimization
      in Lammps based on OpenCL  
      ZHAO Chenglong1,SHI Huibin1,YU Xinfeng2
      2015, 37(09): 1614-1620. doi:
      Abstract ( 405 )   PDF (541KB) ( 475 )     

      Lammps is a widely used open source software for molecular dynamics simulations and related issues, through which we can understand solid and liquid nature. It enables the CUDA and the OpenCL to accelerate calculation. Since the OpenCL has crossplatform features, it becomes a research focus. We summarize the OpenCL kernel programming principles and propose an improved Amdahl's law which can measure the acceleration performance on heterogeneous platforms. The shortrange force algorithm in Lammps on Y485P platform is tested. We achieve better acceleration effect by optimizing the kernel source codes of the key parts, such as neighborlist building and shortrange force calculation.

      An improved hybrid clustering
      algorithm based on large data sets     
      ZHANG Xiao,WANG Hong
      2015, 37(09): 1621-1626. doi:
      Abstract ( 301 )   PDF (759KB) ( 439 )     

      Aiming at the following three problems of the kmeans algorithm:excessive dependence on the initial clustering center, slow convergence speed and insufficient memory when dealing with huge amounts of data, we present a new hybrid clustering algorithm called superkmeans for large data sets. The algorithm combines the kmeans algorithm with the improved highdimensional data clustering algorithm based on the supernetwork. We run it on the Hadoop clusters after the MapReduce parallel processing, and an ideal effect of clustering is achieved. Experimental results show that the algorithm not only improves the convergence and the clustering accuracy but also has high speedup and scalability performance.

      Adjacency matrixbased web service composition 
      LI Jingxia1,WU Guodong1,QIAN Junyan2
      2015, 37(09): 1627-1631. doi:
      Abstract ( 264 )   PDF (442KB) ( 362 )     

      Aiming at the disadvantages in dynamics and algorithm time complexity in the existing web service composition methods, we propose an adjacency matrixbased web service composition approach. Sequential and parallel relationship among web services is represented by adjacency matrix. Abstract services are created by clustering, and the composition relationship among abstract services is established by domain experts. The Warshall algorithm is utilized to calculate the transitive closure of the adjacency matrix so that we can judge whether the  the service request is met or not. Meanwhile the dynamic service composition flow is constructed. The proposed method applies well in service composition due to its simple operation and the O(n3) time complexity of the Warshall algorithm.

      Research on Systolic multiplication technology based on FPGA  
      ZHOU Leitao1,2,TAO Yaodong2,LIU Sheng1,2,LI Suo3
      2015, 37(09): 1632-1636. doi:
      Abstract ( 293 )   PDF (596KB) ( 352 )     

      Systolic multiplication is an algorithm based on the SIMDMC2 model,  but it cannot be applied in the embedded system directly. We propose an implementation of Systolic multiplication by FPGA technology, which combines the hardware parallelism of the FPGA and the parallel algorithm together. To realize Systolic multiplication, we design a node array based on the MC2 model inside the FPGA by making use of the flexible and programmable features of the FPGA. In practical applications, the number and function of the nodes can be modified flexibly to meet the needs of different scale matrixes and the FPGA resources are fully utilized. Simulation results verify the proposed method, and the actual test results show that this method has a faster speed and a higher realtime performance.

      Milance:a cloud image management system
      based on multilevel index  
      LI Siyang,LUO Yu
      2015, 37(09): 1637-1642. doi:
      Abstract ( 267 )   PDF (1826KB) ( 322 )     

      The deployment of OpenStack,an opensource cloud computing platform,has gained popularity for the study of IaaS (Infrastructure as a Service),whereas its resource utilization rate is still low.In order to address this problem,we present a novel image management system,Milance,based on Multilevel Index Glance to replace the existing one which is characterized with a long VM startup latency,a slow snapshop and a large image pool.Experimental results show that in contrast to the existing image management system,Milance not only reduces the latency of VM startups and the cost of snapshots,but also saves more image space.

      An efficient and provably secure proxy blind signature scheme 
      ZHOU Ming,WANG Jian
      2015, 37(09): 1643-1651. doi:
      Abstract ( 225 )   PDF (459KB) ( 291 )     

      By combining the advantages of blind signatures with proxy signatures, a proxy blind signature can be widely applied in many fields, such as ecommerce. Currently, most of the proposed proxy blind signature schemes only give some heuristic explanations without formal proof, and onemore forgery is seldom considered in many schemes. In the paper, we propose a novel efficient security model and a proxy blind signature scheme based on bilinear parings. The scheme is unforgeable against adaptive chosen message/warrant attacks under the Computational DiffieHellman assumption and ChosenTarget Computational DiffieHellman assumption in the random oracle model. The analysis shows that the proposed scheme can satisfy the main secure properties of a proxy blind signature. Furthermore, the scheme is more efficient than traditional ones.

      Security analysis of a digital image encryption algorithm 
      ZHANG Pengwei,ZHANG Tao
      2015, 37(09): 1652-1655. doi:
      Abstract ( 209 )   PDF (437KB) ( 321 )     

      Many of the basic characteristics of the chaotic systems can be linked with the concepts of confusion and diffusion in cryptography, and the chaos theory began to get involved in the cryptography field in the 1980s. As a kind of new cryptography technology, chaotic cipher has become a hot topic in the field of information security in recent years. We study the security of a digital image encryption algorithm, and show that the digital image encryption and decryption algorithm based on Lorenz chaos system is essentially a shift cipher. We also point out the leakage laws of the algorithm and propose a algorithm against known plaintexts attacks. For a  N1×N2 plain image, the computational complexity is (N1×N2)2/212. Theoretical analysis and experimental results demonstrate the insecure feature of this digital image encryption algorithm.

      Design of communication protocol between upper computer
      and data server in seafloor observatory networks 
      XIE Jun1,2,MA Hui2,LI Xiu2
      2015, 37(09): 1656-1660. doi:
      Abstract ( 215 )   PDF (524KB) ( 361 )     

      In seafloor observatory networks, sampling data of each instrument are sent to their own upper computer respectively, which then summarizes all the data and sents them to the data management system server. On the basis of a comprehensive evaluation of data sampling format, data transforming velocity and data transforming capacity, we design a communication protocol between the upper computer and the data server. Package head, package body and cyclic redundancy check (CRC) are included in the communication package. For different upper computers, the format of package head is the same while the format of package body is designed respectively according to the specific characters of the instruments. Besides, we also develop a corresponding client and server software according to the communication protocol. Test results show that the proposed communications protocol can secure full, correct and efficient data transmission from the upper computer to the data sever.

      Binary self-dual codes with 19-(4,f)  automorphism  
      WANG Rong,WANG Junxin
      2015, 37(09): 1661-1666. doi:
      Abstract ( 176 )   PDF (381KB) ( 250 )     

      We discuss the binary selfdual codes of length 76 and 100 with automorphism of order 19. These binary selfdual codes can be seen as a direct sum of contract code of length 4 and some evenweight polynomials over  GF(2)n. We prove that selfdual codes of length between 80 and 100 do not exist. We also construct the binary selfdual codes of length 76, 78 and 80 through the shorter selfdual codes respectively, and present their generator matrices. Simulations in Matlab prove that under the condition of equivalence, there are 11 binary selfdual codes of 19(4, 2) and 19(4,4) types, whereas binary selfdual codes of 19(4, 0) type do not exist.

      A verifiable evoting scheme with multi-candidates 
      LIU Gao1,LIU Yining2,WANG Dong1
      2015, 37(09): 1667-1670. doi:
      Abstract ( 230 )   PDF (357KB) ( 293 )     

      Compared with traditional voting schemes, evoting has been widely studied due to the advantages in contrast, including more security, more efficiency and lower cost. In 2012, Sun et al. proposed a multicandidates evoting scheme based on the secure sum, however, it did not really achieve the verifiability. In this paper, we present an improved version to satisfy the nondeception requirement and guarantee the correctness of the tally results.

      An improved LANDMARC RFID indoor location algorithm  
      CAO Jie1,2,NIU Libo1,WANG Jinhua1
      2015, 37(09): 1671-1675. doi:
      Abstract ( 237 )   PDF (673KB) ( 425 )     

      In the environment of RFID indoor location, the location accuracy of LANDMARC is affected by the number of neighboring reference tags. Traditional algorithms confine to selection of 35 reference tags in a small location environment. However, in a wide location environment, how to select neighboring reference tags is interfered by the neighboring reference tags which are far away from the readers .Therefore, more neighboring reference tags are required to assist locating. But as the number of neighboring reference tags increase the location error will increase accordingly. In order to solve this problem, we introduce the weighted idea in the neighboring reference tags to optimize the calculation of weight distribution, to reduce the error of the system and to thus improve the location accuracy. Simulation results show that the improved LANDMARC localization algorithm possesses higher accuracy in cases of selecting more reference tags.

      A new valuation method based on
      fuzzy mathematics and medium truth theory  
      PAN Qian,ZHANG Yuping,CHEN Haiyan
      2015, 37(09): 1676-1681. doi:
      Abstract ( 219 )   PDF (584KB) ( 323 )     

      Aiming at the evaluation of fuzzy and nondeterministic phenomenon, we propose an evaluation method based on fuzzy mathematics and the medium truth theory. Both the fuzzy mathematics method and the medium truth theory method study and deal with the fuzzy phenomenon from the angle of quantity. But fuzzy synthetic operator of the fuzzy mathematics method is difficult to determine when there are multiple factors, and the measurement range limit in [0,1]. The medium truth theory method also has some limitations in dealing with the situation of multiple factors when evaluate the secondary indicators. Therefore, we combine the fuzzy mathematics method and the medium truth theory method: using the former to evaluate the secondary indicators, and the latter for the first indicators, thus the best option is obtained. Finally, we apply the proposed method to software quality evaluation and compare its results with those of the fuzzy mathematics method and the medium truth theory method, Test results show that our method is feasible and reasonable, and has certain advantages.

      Research on multiagent cooperation stability based #br# on the punishment mechanism of evolutionary games 
      ZHENG Yanbin, DUAN Lingyu, LI Bo, LIANG Kai
      2015, 37(09): 1682-1687. doi:
      Abstract ( 265 )   PDF (586KB) ( 323 )     

      The coordination stability problem in complex environments is one of the key problems in the research of multiagent cooperation. We present a multiagent cooperation stability method on the basis of game theory methods and punishment mechanism. To maintain the stability of multiagent cooperation and achieve a balanced cooperation, a punishment is introduced and continuous adjustment of the penalty factors is performed. Agent credit values are fully considered when the cooperation team is formed. Simulation results show that the proposal can not only reduce task completion time effectively, but also avoid agent exits in the dynamic cooperation, thus improving the cooperation efficiency and stability.

      论文
      Research and implementation of
      an improved MVC design pattern  
      LIU Hongxia,LU Wendi
      2015, 37(09): 1688-1691. doi:
      Abstract ( 215 )   PDF (578KB) ( 280 )     

      The traditional MVC design pattern on .NET platform has defects of defects of  low data processing capability and low code reuse. Using the middleware and asynchronous refresh techniques, we propose an improved MVC design pattern. Based on the improved MVC, we design a quality objection replacement system for iron and steel enterprises. System operation indicates the improved MVC effectively enhances the robustness of the system, balances the coupling between layers and increases the code reuse rate and the efficiency of system development.

      An artificial bee colony algorithm with
      adaptive chemotaxis and guiding factors 
      ZANG Peiquan,SUN Chenao,GU Xiaofeng,WU Bin,ZHOU Changxi
      2015, 37(09): 1692-1697. doi:
      Abstract ( 217 )   PDF (714KB) ( 299 )     

      We propose an improved artificial bee colony (ABC) algorithm to overcome the drawbacks of slow convergence rate and low optimization precision of the conventional ABC algorithm. The selfadaptive chemotaxis and guiding factors are introduced into the search schemes of employed bees and onlooker bees, respectively. Under the guidance of the guiding factors, the local search capability is significantly improved due to the employed bees’ dynamic search for the high quality nectar sources and the onlooker bees’ cooperative search for the better nectar sources. Simulation results based on the eight standard functions show that the improved ABC algorithm is superior to the conventional one in both computational accuracy and convergence rate.

      An improved differential evolution algorithm based on JADE
      LI Kangshun,WANG Fajie,ZHANG Chuhu,YANG Lei,CHEN Yan
      2015, 37(09): 1698-1706. doi:
      Abstract ( 276 )   PDF (765KB) ( 309 )     

      Differential evolution algorithms are weak in local searching and easy to dropping into the local optimal solutions at the same time. The search performance of these algorithms is mainly based on the parameter setting of their crossover probability and mutation factors. To improve the above shortcomings of differential evolution algorithms, we propose an adaptive differential evolution algorithm called ZJADE on the basis of indepth research and analysis of the adaptive differential evolution with optional external archive (JADE). Skew tent chaotic mapping is used to initialize the population in order to generate uniformly dispersed population. During each generation, the crossover probability of each individual is generated according to the normal distribution and the Cauchy distribution while the mutation factors are independently generated according to the normal distribution. The crossover probability and mutation factors of successful individuals are saved, and the statistical crossover probability is employed. The ZJADE algorithm is compared with multiple stateoftheart adaptive differential evolution algorithms through thirteen classical test functions. The results show that the ZJADE obtains better solution accuracy and quicker convergence speed, thus having a better search performance.

      Application of BP neural network in the early-warning
      of fruits and vegetables cold-chain logistics
      YANG Wei,CAO Wei
      2015, 37(09): 1707-1711. doi:
      Abstract ( 193 )   PDF (843KB) ( 287 )     

      In recent years, consumers ask for a higher demand on the security and quality of fruit and vegetable products. But the existing system can only predict the state of fruits and vegetables based on the temperature and humidity of the environment, and factors such as personnel operation and equipment are not taken into account. To solve these problems, we analyze the factors which affect the quality of fruits and vegetables in the cold-chain process, establish the early warning index system, and integrate the traceable and monitorable information in the supply chain. The BP neural network is utilized to build the security warning model, and we train it and make prediction. The results show that the proposed method has fewer errors than traditional time-series and regression analysis methods when solving practical problems, and can effectively increase the security risks and hazards warning accuracy of fruits and vegetables in cold-chain logistics.

      A study of the cell formation problems
      based on a novel ant colony algorithm 
      L Congying
      2015, 37(09): 1712-1717. doi:
      Abstract ( 180 )   PDF (789KB) ( 283 )     

      The ant colony algorithm for solving cell formation problems tends to fall into early mature convergence status. In order to overcome this defect, we propose a mixed algorithm of the ant colony algorithm, the auditory signal and the memory matrix. In the simulation experiments, the ant colony algorithm, the ant colony algorithm containing auditory signals, the ant colony algorithm containing memory matrixes, and the proposed novel algorithm are adopted respectively to solve cell formation problems. Experimental results show that the proposed algorithm outperforms the other three in terms of enhancing global optimization capacity and convergence speed of the ant colony algorithm. At the same time, the group efficiency obtained by the proposed algorithm is better than the three aforementioned algorithms and the existing hybrid genetic algorithms.

      A 3D terrain reconstruction algorithm
      based on SLIC segmentation   
      CHANG Fangyuan1,FENG Zhiyong1,XU Chao2
      2015, 37(09): 1718-1723. doi:
      Abstract ( 232 )   PDF (736KB) ( 355 )     

      Most traditional 3D terrain reconstruction algorithms cannot represent the accurate structure of the terrain and are time consuming as well, thus the technological development is seriously hindered . In order to realize the 3D terrain reconstruction accurately by using pictures taken by unmanned aerial vehicle (UAV) with the advantages of high resolution, wide camera range and low demand of shot environment, we propose a method that generates digital elevation model (DEM) data respectively in different superpixel terrain areas by segmenting the images at the preprocessing stage. Firstly, the simple linear iterative clustering (SLIC) algorithm, which shows good performance in superpixel generation and is convenient to use, is adopted to segment the images into multiple superpixel terrain areas which contain just a single terrain type. Then the adjacent superpixel  areas containing the same terrain are fused according to the LAB color information, in which way the number of superpixel areas is decreased and the speed of the algorithm is improved. Thirdly the scaleinvariant feature transform (SIFT) feature points’ extraction and matching are done in each area. Based on the matching results, the 3D coordinates are computed with the method of binocular stereo vision and DEM data are generated in the end to reconstruct the terrain. Comparing with the satellite map, the proposed algorithm can reconstruct 3D terrains effectively, and it can present the boundaries information accurately in contrast with traditional 3D terrain algorithms.