Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2019-01-28 Cooperative journals: 《计算机应用研究》
Abstract： In order to migrate Docker container based applications across heterogeneous container clouds, the author studied the principles of mainstream heterogeneous container orchestrating engines. Meanwhile, this paper conducted a survey on the heterogeneity of container service of different providers. The author proposed the Three-layered Model of Migrating Docker Container based Applications across Heterogeneous Container Clouds. Four the purpose of improving migration efficiency, this paper developed the Image Pre-Synchronization technology. Experimental results show that using the three-layered model can migrate Docker container based applications across container clouds successfully, and the technology of image pre-synchronization can help the time of migrating. For the situation of migrating Docker container based applications between heterogeneous container orchestrating engines in homogeneous clouds, the improvement is 60.33% on average. And for the situation of migrating Docker container based applications between Kubernetes clusters in heterogeneous clouds, the improvement is 43.67% on average.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-07-09 Cooperative journals: 《计算机应用研究》
Abstract： This paper analyzed the characteristics and deficiencies of chi-square statistics and expected cross-entropy methods for feature selection of text classification. In order to avoid the poor classification of traditional CHI and ECE methods on unbalanced data sets, this paper presented an improved CHI method (pCHI) by introducing adjustment factors and removing negative correlation influencing factors, and presented a weighted ECE method(ωECE) to compensate the disadvantages of the ECE method tending to select high-frequency features of weak distinguishing ability. After synthesizing the two improved methods, this paper further proposed a feature selection method based on combining improved CHI and weighted ECE (pCHIωECE) . Through comparative experiments, the precision rate and F1 value of the pCHIωECE method are both superior to those of the CHI, ECE, pCHI and ωECE methods, and moreover, the dimensionality and stability of the method are better.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-06-19 Cooperative journals: 《计算机应用研究》
Abstract： Decentralized public key infrastructure based on blockchain abandons certificate authority. With authoritativeness and publicity of the blockchain, this infrastructure is able to implement decentralized identity authentication. Many researches chose to traverse the entire blockchain to look up for a specific id-pk pair and then verify whether the public key belongs to someone who claims it. However, this method is obviously inefficient. This paper proposed an identity authentication method based on cryptographic accumulators, which map identity, public key and auxiliary information to one accumulated value. This method improved the authentication efficiency, especially when current blockchain was large. In addition, it solved the problem that lightweight clients do not had enough storage capacity when the size of blockchain was continuously increasing. Some experiments are also carry to measure this method and verify its feasibility and correctness.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-05-18 Cooperative journals: 《计算机应用研究》
Abstract： Researched on the task dividing method based on the architecture of the network emulation for the fusion of virtualization and digital simulation to improve the performance. This method took into account the advantages of virtualization and digital simulation, and the emulation network topology was divided into virtualization topology area and digital simulation topology area, and then divided the two topology area combined with given physical resources aiming at load balancing and remote traffic minimizing. Extensive experiments showed that using the method to divide the network emulation task, the remote traffic was reduced by 33.7%, 25.1% averagely, and the degree of load balancing was improved by 56.3%, 38.0% averagely, compared with the random algorithm and the uniform load balancing algorithm. The task dividing method can effectively reduce the remote traffic and improve the degree of load balancing.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-17 Cooperative journals: 《计算机应用研究》
Abstract： In order to solve long time consuming problems of single CPU computed tomographic reconstruction and the problems of high cost and high energy consumption in the reconstruction using CPU cluster, this paper proposed a heterogeneous reconstruction model of CPU multithreads +GPU . This model used the CPU multithread pipelining pattern, it divided the whole task into several stages, and it connected each two adjacent phases by a loop buffer. Once the calculation of the current task stage completes, the data would be put into the loop buffer, and then the next computing task would continue to execute. When the data in the loop buffers was detected by the latter stage, the data would be removed from the loop buffers and calculated. In this way, each thread processes tasks in a parallel way. For a time consuming bottleneck module, the parallel acceleration of GPU was adopted to give full play to the computing resources of CPU and GPU. The CPU multithreads +GPU model is 16.45 times faster than the CPU multithreaded model, and accelerates more than 20.5 times faster than serial CT image reconstruction. By燾omparing with爀xperimental爎esults of CPU serial program, the result of the CPU multithreads +GPU model can meet the experimental design requirement in the range of error tolerance. The image reconstruction model proposed by using low cost GPU has greatly enhanced performance, greatly reduces the cost and power consumption of the CT system . The reduction in cost and power consumption will lead to a reduction in the cost of CT medical diagnosis, which will eventually benefit patients.
Subjects: Computer Science >> Integration Theory of Computer Science submitted time 2018-04-12 Cooperative journals: 《计算机应用研究》
Abstract： Opaque predicate is a lightweight obfuscation method which holds partial observability and is used to impede reverse engineering. Generalized Opaque Predicate extends the property of narrow Opaque Predicate by turning fixed value to fixed logic, and it is applied in malware. In order to eliminate the disturbance introduced by opaque predicates during malware identifying, a generalized opaque predicate detecting method is proposed based on the consistency of logic, this method depends on the reliance on constraint, and combines with the identification of consistency toward logic. Our method extracts previous constraint of domain, back constraint of logic and expression of predicate, then filters candidates by applying search of intersecting basic blocks, and finally identifies opaque predicates through constraint solving. We designed a prototype and the evaluation indicates that our method could identify opaque predicates from malware accurately and effectively.
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