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A cost model for automatic OpenMP parallelization

Ruan Jian Xue Bao/Journal of Software 2014年 25卷 101-110页

作者： Li, Yan-Bing Zhao, Rong-Cai Liu, Xiao-Xian Zhao, Jie PLA Information Engineering University Zhengzhou450001 China State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou450001 China Logistics Information Center Guangzhou Military Region Joint Logistics Department Guangzhou510000 China

Existing OpenMP cost models does not give enough thought to the implementation details of OpenMP programs so they cannot be applied widely to different types of parallel loops. To solve this problem, this study extends the cost model in the most advanced product-level optimizing compiler Open64. Targeting single candidate parallel loop, it establishes a cost model suite for the OpenMP benefit analysis. Besides improving the original DOALL-loop faced cost model in the Open64 compiler, two additional models which are also designed for DOACROSS and DSWP (Decoupled Software Pipelining) loops respectively. The experimental results show that the proposed cost model suite can simulate the execution cost of parallel programs very well, and therefore can better support cost evaluation of OpenMP parallelization. ©2014 ISCAS.

关键词： Cost benefit analysis

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Research on Stream Cipher Model Based on Chaos Theory

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International Journal of Technology Management 2013年第2期 91-93页

作者： Sun Wenjie State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou Henan 102206

Chaos is a similar and random process which is very sensitive to initial value in deterministic system. It is a performance of nonlinear dynamical system with built-in randomness. Combined with the advantages and disadvantages of the present chaos encryption model, the paper proposes a chaotic stream cipher model based on chaos theory, which not only overcomes finite precision effect, but also improves the randomness of chaotic system and output sequence. The Sequence cycle theory generated by the algorithm can reach more than 10600 at least, which completely satisfies the actual application requirements of stream cipher system.

关键词： chaos theory stream cipher algorithm

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Method based on GSCPN for network vulnerability analysis

Journal of Software

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Journal of Software 2013年第8期8卷 2032-2038页

作者： Gao, Xiang Zhu, Yue-Fei Fei, Jin-Long Han, Tao State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou 450002 China

With the development of network security research, network attack modeling and analysis techniques have been paid more and more attention. A generalized stochastic colored Petri Net (GSCPN) Model is proposed. To each attack, a GSCPN model is constructed to describe the relation of components graphically. Algorithm to construct a composite attack and method for network vulnerability analysis are delivered also. The exploitation cost of vulnerabilities is estimated. The method is relatively simple, which is different from traditional method. The network example further validates the proposed method for network vulnerability analysis. © 2013 ACADEMY PUBLISHER.

关键词： Network security

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An Automatic Parallel-Stage Decoupled Software Pipelining Parallelization Algorithm Based on OpenMP

An Automatic Parallel-Stage Decoupled Software Pipelining Pa...

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IEEE International Conference on Trust, Security and Privacy in computing and Communications (TrustCom)

作者： Xiaoxian Liu Rongcai Zhao Lin Han Peng Liu State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou China

ISBN: (纸本)9781479914449

While multicore processors increase throughput for multi-programmed and multithreaded codes, many important applications are single threaded and thus do not benefit. Automatic parallelization techniques play an important role in migrating singe threaded applications to multicore platforms. Unfortunately, the prevalence of control flow, recursive data structures, and general pointer accesses in ordinary programs renders the traditional automatic parallelization techniques unsuitable. Parallel-Stage Decoupled Software Pipelining (PS-DSWP) is proposed to exploit fine-grained pipeline parallelism lurking in ordinary programs with the existence of all kinds of dependences, including arbitrary control dependences, at the instruction level. But it requires knowledge of architectural properties and hardware support of a communication channel and two special instructions. We propose an improved PS-DSWP algorithm based on OpenMP in this paper. It is implemented without relying on CPU architectures by using a high level intermediate representation. Moreover, the Program Dependence Graph (PDG) used in the algorithm is built based on the basic blocks, which exploits coarser-grained parallelism than the original PS-DSWP transformation with PDG based on instructions. OpenMP is employed in our algorithm to assign task and implement synchronization among threads while avoiding dependence on hardware support. We evaluate the loops with complex memory patterns and control flow, which cannot be dealt with by traditional techniques, on multicore platform. As a result, they can be parallelized and gain significant performance improvement with our algorithm. We obtain a maximum speedup as high as 2.07x and on average 1.39x with 5 threads.

关键词： Instruction sets Synchronization Pipeline processing Multicore processing Merging

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Convergence and Scalarization in Whole Function Vectorization

Convergence and Scalarization in Whole Function Vectorizatio...

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IEEE International Symposium on Dependable, Autonomic and Secure computing (DASC)

作者： Feng Yue Jianmin Pang Jiuzhen Jin Dai Chao State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou China

When implementing SPMD programs on multi core platforms, whole function vectorization is an important optimization method. SPMD program has drawback that lots of instructions across multi threads are redundant which is sustained in vectorization. This paper proposes to alleviate this overhead by detecting scalar operations and extract them out in vectorization instructions. An algorithm is designed to deal with control flow and data flow synchronously in which convergent and invariance analysis is employed to statically identify convergent execution and invariant values or instructions. Our algorithm is effectively on implementing SPMD programs on multi core platforms. The experiments show our method could improve the execution efficiency by 13.3%.

关键词： Convergence Optimization Algorithm design and analysis Vectors Instruction sets Graphics processing units Multicore processing

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One Wide-Sense Circuit Tree per Traffic Class Based Inter-domain Multicast

One Wide-Sense Circuit Tree per Traffic Class Based Inter-do...

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International Conference on Networking, Architecture, and Storage (NAS)

作者： Chen Yue Li Chaoling Huang Kaixiang Zhang Xiaobo State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou China

Traditional multicast protocol forms multicast trees rooted at different sources to forward packets. If the multicast sources and receivers are in different domains, these trees will produce a great number of multicast states in the backbone, resulting in poor scalability. Therefore, we propose a one Wide-Sense Circuit Tree per Traffic Class based inter-domain multicast (WSCT-TC), in which a Wide-Sense Circuit Tree (WSCT) is established for a class of multicast traffic. The WSCT is established in the backbone, along which multicast packets are forwarded by label switching. The spec of WSCT can be reconfigured according to the QoS (Quality of Service) requirement of multicast applications, to provide preferable QoS. Simulating experiment shows that WSCT-TC behaves better scalability.

关键词： Switches Receivers IP networks Quality of service Routing protocols Internet

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The Speedup Model for Manycore Processor

The Speedup Model for Manycore Processor

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International Conference on Information Science and Cloud computing Companion (ISCC-C)

作者： Nan Ye Ziyu Hao Xianghui Xie State Key Laboratory of Mathematical Engineering and Advanced Computing Wuxi China

ISBN: (纸本)9781479952465

Integrating a large number of simple cores on the chip to provide the desired performance and throughput, microprocessor has entered the many core era. In order to fully extract the ability of the many core processor, we propose speedup models for many core architecture in this paper. Under the assumption of Hill-Marty model, we deduce our formulas based on Gustafson's Law and Sun-Ni's Law. Then, compared with the Hill-Marty model, we theoretically analyze the best allocation under the given resources. Furthermore, we apply the conclusions of our models to evaluate current many core processors and predict concrete future architecture. Our results show that the many core architecture is capable of extensive scalability and being beneficial to promote the performance, especially heterogeneous one. By using simple analytical models, we provide a better understanding of architecture design and our work complement existing studies.

关键词： Computational modeling Computer architecture Complexity theory Analytical models Parallel processing Predictive models Resource management

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Embedding change rate estimation based on ensemble learning 13

Embedding change rate estimation based on ensemble learning

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1st ACM Workshop on Information Hiding and Multimedia Security, IH and MMSec 2013

作者： Li, Zhenyu Hu, Zongyun Luo, Xiangyang Lu, Bin State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou 450002 China Zhengzhou Institute of Information Science and Technology Zhengzhou 450002 China State Key Laboratory of Information Security Institute of Information Engineering Chinese Academy of Sciences Beijing 100093 China

ISBN: (纸本)9781450320818

In order to achieve higher estimation accuracy of the embedding change rate of a stego object, an ensemble learning-based estimation method is presented. First of all, a framework of embedding change rate estimation based on estimator ensemble is proposed. Then an algorithm of building the estimator ensemble, the core of the framework, is concretely described. Finally, a pruning method for estimator ensemble is proposed in consideration of both the diversity among the base estimators and accuracy of each of them. The experimental results for three modern steganographic algorithms (nsF5, PQ and PQt) indicate that the proposed method acquired better performance than the existed typical method. Furthermore, the pruned estimator ensemble with less base estimators maintained, even slightly improved the estimation accuracy, compared to the one without purning. © 2013 ACM.

关键词： Steganography

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Steganographic codes by applying syndrome-trellis codes to dynamic distortion model in pixel chain

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Jisuanji Yanjiu yu Fazhan/Computer Research and Development 2014年第8期51卷 1739-1747页

作者： Bao, Zhenkun Zhang, Weiming Cheng, Sen Zhao, Xianfeng The Fourth Institute Information Engineering University Zhengzhou450002 China State Key Laboratory of Mathematical Engineering and Advanced Computing Information Engineering University Zhengzhou450002 China School of Information Science and Technology University of Science and Technology of China Hefei230026 China Institute of Information Engineering Chinese Academy of Sciences Beijing100093 China State Key Laboratory of Information Security Instituteof Information Engineering Chinese Academy of Sciences Beijing100093 China

Double-layered STC (syndrome trellis code) is the most popular method for minimizing the distortion of ± 1 steganography. However, it is a probabilistic algorithm which may fail in the embedding process on some given profiles. Another characteristic of double-layered STC is the high computational complexity. Starting from these two points, we propose a dynamic distortion model defined in a pixel chain in this paper. The dynamic distortion model is working on a principle that the SLSB (second least significant bit) of current pixel is used to control the LSB (least significant bit) of the next pixel. So the distortion of some pixels may be adjusted to zero by this means. We apply STC to fit the dynamic distortion model and get a novel method for ± 1 steganography. Comparing with the double-layered STC, the experiment result shows that the proposed method has comparable ability for minimizing distortion with significantly improved embedding speed. And this novel method avoids failure in the embedding process. Considering the advantages together, the method is more suitable for steganography systems and software in practical environment.

关键词： Pixels

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Steganalysis of F5-like steganography based on selection of joint distribution features 13

Steganalysis of F5-like steganography based on selection of ...

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5th International Conference on Internet Multimedia computing and Service, ICIMCS 2013

作者： Liu, Yuan Luo, Xiangyang Lu, Jicang Gong, Daofu Zhengzhou Information Science and Technology Institute Zhengzhou 450001 China State Key Laboratory of Information Security Institute of Information Engineering Chinese Academy of Sciences Beijing 100093 China Zhengzhou Information Science and Technology Institute State Key Laboratory of Mathematical Engineering and Advanced Computing Zhengzhou 450001 China

ISBN: (纸本)9781450322522

For steganalysis of F5-like steganography with two types of widely used joint distribution statistical features: co-occurrence matrix and Markov transition probability matrix, a feature selection and fusion method based on separability comparison is proposed in this paper. Firstly, the changing ways of F5-like steganography to image data is analyzed. Then, according to different affecting ways of the changing to two types of features, the separability of each feature component is analyzed and compared. At last, based on the comparison conclusion, a new feature is obtained by selection and fusion. Experimental results show that, compared with existing typical features, the proposed new feature can achieve higher steganalytic accuracy and enhance the detection reliability. © 2013 ACM.

关键词： Steganography

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