Tsinghua Science and Technology

  • M2M:A Simple Matlab-to-MapReduce Translator for Cloud Computing

    Junbo Zhang;Dong Xiang;Tianrui Li;Yi Pan;

    MapReduce is a very popular parallel programming model for cloud computing platforms, and has become an effective method for processing massive data by using a cluster of computers. X-to-MapReduce (X is a program language) translator is a possible solution to help traditional programmers easily deploy an application to cloud systems through translating sequential codes to MapReduce codes. Recently, some SQL-to-MapReduce translators emerge to translate SQL-like queries to MapReduce codes and have good performance in cloud systems. However, SQL-to-MapReduce translators mainly focus on SQL-like queries, but not on numerical computation. Matlab is a high-level language and interactive environment for numerical computation, visualization, and programming, which is very popular in engineering. We propose and develop a simple Matlab-to-MapReduce translator for cloud computing, called M2M, for basic numerical computations. M2M can translate a Matlab code with up to 100 commands to MapReduce code in few seconds, which may cost a proficient Hadoop MapReduce programmer some days on coding so many commands. In addition, M2M can also recognize the dependency between complex commands, which is always confusing during hand coding. We implemented M2M with evaluation for Matlab commands on a cluster. Several common commands are used in our experiments. The results show that M2M is comparable in performance with hand-coded programs.

    2013年01期 v.18 1-9页 [查看摘要][在线阅读][下载 703K]
    [下载次数:176 ] |[网刊下载次数:0 ] |[引用频次:14 ] |[阅读次数:57 ]
  • Transparent Computing: Spatio-Temporal Extension on von Neumann Architecture for Cloud Services

    Yaoxue Zhang;Yuezhi Zhou;

    The rapid advancements in hardware, software, and computer networks have facilitated the shift of the computing paradigm from mainframe to cloud computing, in which users can get their desired services anytime, anywhere, and by any means. However, cloud computing also presents many challenges, one of which is the difficulty in allowing users to freely obtain desired services, such as heterogeneous OSes and applications, via different light-weight devices. We have proposed a new paradigm by spatio-temporally extending the von Neumann architecture, called transparent computing, to centrally store and manage the commodity programs including OS codes, while streaming them to be run in non-state clients. This leads to a service-centric computing environment, in which users can select the desired services on demand, without concern for these services' administration, such as their installation, maintenance, management, and upgrade. In this paper, we introduce a novel concept, namely Meta OS, to support such program streaming through a distributed 4VP + platform. Based on this platform, a pilot system has been implemented, which supports Windows and Linux environments. We verify the effectiveness of the platform through both real deployments and testbed experiments. The evaluation results suggest that the 4VP + platform is a feasible and promising solution for the future computing infrastructure for cloud services.

    2013年01期 v.18 10-21页 [查看摘要][在线阅读][下载 714K]
    [下载次数:88 ] |[网刊下载次数:0 ] |[引用频次:19 ] |[阅读次数:29 ]
  • GPGPU Cloud: A Paradigm for General Purpose Computing

    Liang Hu;Xilong Che;Zhenzhen Xie;

    The Kepler General Purpose GPU (GPGPU) architecture was developed to directly support GPU virtualization and make GPGPU cloud computing more broadly applicable by providing general purpose computing capability in the form of on-demand virtual resources. This paper describes a baseline GPGPU cloud system built on Kepler GPUs, for the purpose of exploring hardware potential while improving task performance. This paper elaborates a general scheme which defines the whole cloud system into a cloud layer, a server layer, and a GPGPU layer. This paper also illustrates the hardware features, task features, scheduling mechanism, and execution mechanism of each layer. Thus, this paper provides a better understanding of general-purpose computing on a GPGPU cloud.

    2013年01期 v.18 22-33页 [查看摘要][在线阅读][下载 1903K]
    [下载次数:57 ] |[网刊下载次数:0 ] |[引用频次:2 ] |[阅读次数:54 ]
  • A Load Balancing Model Based on Cloud Partitioning for the Public Cloud

    Gaochao Xu;Junjie Pang;Xiaodong Fu;

    Load balancing in the cloud computing environment has an important impact on the performance. Good load balancing makes cloud computing more efficient and improves user satisfaction. This article introduces a better load balance model for the public cloud based on the cloud partitioning concept with a switch mechanism to choose different strategies for different situations. The algorithm applies the game theory to the load balancing strategy to improve the efficiency in the public cloud environment.

    2013年01期 v.18 34-39页 [查看摘要][在线阅读][下载 1709K]
    [下载次数:96 ] |[网刊下载次数:0 ] |[引用频次:36 ] |[阅读次数:49 ]
  • Cloud Computing-Based Forensic Analysis for Collaborative Network Security Management System

    Zhen Chen;Fuye Han;Junwei Cao;Xin Jiang;Shuo Chen;

    Internet security problems remain a major challenge with many security concerns such as Internet worms, spam, and phishing attacks. Botnets, well-organized distributed network attacks, consist of a large number of bots that generate huge volumes of spam or launch Distributed Denial of Service (DDoS) attacks on victim hosts. New emerging botnet attacks degrade the status of Internet security further. To address these problems, a practical collaborative network security management system is proposed with an effective collaborative Unified Threat Management (UTM) and traffic probers. A distributed security overlay network with a centralized security center leverages a peer-to-peer communication protocol used in the UTMs collaborative module and connects them virtually to exchange network events and security rules. Security functions for the UTM are retrofitted to share security rules. In this paper, we propose a design and implementation of a cloud-based security center for network security forensic analysis. We propose using cloud storage to keep collected traffic data and then processing it with cloud computing platforms to find the malicious attacks. As a practical example, phishing attack forensic analysis is presented and the required computing and storage resources are evaluated based on real trace data. The cloud-based security center can instruct each collaborative UTM and prober to collect events and raw traffic, send them back for deep analysis, and generate new security rules. These new security rules are enforced by collaborative UTM and the feedback events of such rules are returned to the security center. By this type of close-loop control, the collaborative network security management system can identify and address new distributed attacks more quickly and effectively.

    2013年01期 v.18 40-50页 [查看摘要][在线阅读][下载 9205K]
    [下载次数:885 ] |[网刊下载次数:0 ] |[引用频次:47 ] |[阅读次数:249 ]
  • C-HMAX: Artificial Cognitive Model Inspired by the Color Vision Mechanism of the Human Brain

    Bo Yang;Lipu Zhou;Zhidong Deng;

    Artificial cognitive models and computational neuroscience methods have garnered great interest from both neurologist and leading analysts in recent years. Among the cognitive models, HMAX has been widely used in computer vision systems for its robustness shape and texture features inspired by the ventral stream of the human brain. This work presents a Color-HMAX (C-HMAX) model based on the HMAX model which imitates the color vision mechanism of the human brain that the HMAX model does not include. C-HMAX is then applied to the German Traffic Sign Recognition Benchmark (GTSRB) which has 43 categories and 51 840 sample traffic signs with an accuracy of 98.41%, higher than most other models including linear discriminant analysis and multi-scale convolutional neural network.

    2013年01期 v.18 51-56页 [查看摘要][在线阅读][下载 471K]
    [下载次数:69 ] |[网刊下载次数:0 ] |[引用频次:3 ] |[阅读次数:90 ]
  • Low Complexity LDPC Decoder with Modified Sum-Product Algorithm

    Chen Qian;Weilong Lei;Zhaocheng Wang;

    This paper describes an efficient implementation of the Sum-Product Algorithm (SPA) within a Low Density Parity Check (LDPC) code decoder, where a horizontal process correction term is used to improve the decoding performance of the Min-Sum algorithms. The correction term is implemented as a look-up table. The algorithm uses the correction term redundancy by means of a coordinate transformation to reduce the hardware complexity. Simulations and hardware tests indicate that the decoding performance is very good with the appropriate look-up table.

    2013年01期 v.18 57-61页 [查看摘要][在线阅读][下载 411K]
    [下载次数:46 ] |[网刊下载次数:0 ] |[引用频次:8 ] |[阅读次数:31 ]
  • Sparse Representation for Face Recognition Based on Constraint Sampling and Face Alignment

    Jing Wang;Guangda Su;Ying Xiong;Jiansheng Chen;Yan Shang;Jiongxin Liu;Xiaolong Ren;

    Sparse Representation based Classification (SRC) has emerged as a new paradigm for solving recognition problems. This paper presents a constraint sampling feature extraction method that improves the SRC recognition rate. The method combines texture and shape features to significantly improve the recognition rate. Tests show that the combined constraint sampling and facial alignment achieves very high recognition accuracy on both the AR face database (99.52%) and the CAS-PEAL face database (99.54%).

    2013年01期 v.18 62-67页 [查看摘要][在线阅读][下载 419K]
    [下载次数:108 ] |[网刊下载次数:0 ] |[引用频次:10 ] |[阅读次数:28 ]
  • Knowledge Map Mining of Financial Data

    Wenhui Shou;Wenhui Fan;Boyuan Liu;Yuyang Lai;

    The Knowledge Map (KM) concept, which was derived from the Fuzzy Cognitive Map (FCM), is used to describe and manage knowledge. KM provides insight into the interdependencies and uncertainties contained in the system. This paper uses a model-free method to mine KMs in historical data to analyze component stock corporations of the Shanghai Stock 50 index. The analyses use static and time-domain analyses. The results indicate that a knowledge map is useful for representing knowledge and for monitoring the health of companies. Furthermore, sudden changes of the key features of the KMs should be taken seriously by policymakers as an alarm of a crisis.

    2013年01期 v.18 68-76页 [查看摘要][在线阅读][下载 1205K]
    [下载次数:65 ] |[网刊下载次数:0 ] |[引用频次:3 ] |[阅读次数:46 ]
  • Ginix: Generalized Inverted Index for Keyword Search

    Hao Wu;Guoliang Li;Lizhu Zhou;

    Keyword search has become a ubiquitous method for users to access text data in the face of information explosion. Inverted lists are usually used to index underlying documents to retrieve documents according to a set of efficiently. Since inverted lists are usually large, many compression techniques have been proposed to reduce the storage space and disk I/O time. However, these techniques usually perform decompression operations on the fly, which increases the CPU time. This paper presents a more efficient index structure, the Generalized INverted IndeX (Ginix), which merges consecutive IDs in inverted lists into intervals to save storage space. With this index structure, more efficient algorithms can be devised to perform basic keyword search operations, i.e., the union and the intersection operations, by taking the advantage of intervals. Specifically, these algorithms do not require conversions from interval lists back to ID lists. As a result, keyword search using Ginix can be more efficient than those using traditional inverted indices. The performance of Ginix is also improved by reordering the documents in datasets using two scalable algorithms. Experiments on the performance and scalability of Ginix on real datasets show that Ginix not only requires less storage space, but also improves the keyword search performance, compared with traditional inverted indexes.

    2013年01期 v.18 77-87页 [查看摘要][在线阅读][下载 924K]
    [下载次数:37 ] |[网刊下载次数:0 ] |[引用频次:4 ] |[阅读次数:21 ]
  • Differential Coherent Algorithm Based on Fast Navigation-Bit Correction for Airborne GNSS-R Software Receivers

    Yiran Wang;Bo Zhang;Dingrong Shao;

    Signals from the Global Navigation Satellite System (GNSS) scatter over the sea surface resulting in relatively low Signal-to-Noise Ratios (SNR). A differential coherent algorithm is given here to improve the SNR and reduce the performance degradation due to the Squaring-Loss and the navigation-bit effect. The algorithm uses fast navigation-bit correction for Delay-Doppler Maps (DDM) in airborne Global Navigation Satellite Signal Reflectometry (GNSS-R) software receivers. The system model is introduced with an analysis of the statistical properties with simulations to support the theoretical analysis. Field experiments with real airborne receivers then demonstrate the effectiveness of this algorithm. Comparisons with test results show that this algorithm offers a significant SNR gain over conventional algorithms.

    2013年01期 v.18 88-99页 [查看摘要][在线阅读][下载 1338K]
    [下载次数:82 ] |[网刊下载次数:0 ] |[引用频次:2 ] |[阅读次数:74 ]
  • RISE: A RelIable and SEcure Scheme for Wireless Machine to Machine Communications

    Wei Ren;Linchen Yu;Liangli Ma;Yi Ren;

    Wireless Machine to Machine (M2M) communications enable ubiquitous sensing, controlling, and acting via sensors, actuators, and actors. Reliability and security are of foremost importance in wireless M2M systems. A simple, target distinguishing attack can result in M2M's failure. This paper presents a RelIable and SEcure scheme, RISE, which is a package of policies that guarantee the reliability of data (including sensor reports and actuator instructions) and devices (including sensors, actuators, and actors). The data reliability is improved by four algorithms, ChooseMedian, ChooseMost, ChooseNearest, and Trust-based Enhancement. Report attainability is improved via m repeat-sending and n multiple-reporting algorithms. Device reliability is guaranteed by device-indistinguishability, which comprises data-indistinguishability and behavior-indistinguishability. The security requirements are formally defined, and the security analysis proves the soundness and completeness of the scheme.

    2013年01期 v.18 100-107页 [查看摘要][在线阅读][下载 511K]
    [下载次数:41 ] |[网刊下载次数:0 ] |[引用频次:2 ] |[阅读次数:25 ]
  • Special Section of Tsinghua Science and Technology on Wireless Computing and Networking

    <正>The publication of Tsinghua Science and Technology was started in 1996. Since then, it has been an international academic journal sponsored by Tsinghua University and published bimonthly. This journal aims at presenting the state-of-art scientific achievements in computer science, and other IT fields, and is currently indexed by Ei and other abstracting indices. From year 2013, the journal will be available for open access through IEEE Xplore Digital Library.

    2013年01期 v.18 108页 [查看摘要][在线阅读][下载 62K]
    [下载次数:14 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:26 ]
  • Information for Contributors

    <正>Tsinghua Science and Technology(Tsinghua Sci Technol),an academic journal sponsored by Tsinghua University,is published bimonthly.This journal aims at presenting the up-to-date scientific achievements with high creativity and great significance in computer and electronic engineering.Contributions all over the world are welcome.

    2013年01期 v.18 109页 [查看摘要][在线阅读][下载 571K]
    [下载次数:10 ] |[网刊下载次数:0 ] |[引用频次:0 ] |[阅读次数:24 ]
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