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Tsinghua Science and Technology

Issue 4 • Date Aug. 2011

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Displaying Results 1 - 17 of 17
  • [Front cover]

    Publication Year: 2011, Page(s): c1
    IEEE is not the copyright holder of this material | PDF file iconPDF (1147 KB)
    Freely Available from IEEE
  • Contents

    Publication Year: 2011, Page(s): 1
    IEEE is not the copyright holder of this material | PDF file iconPDF (94 KB)
    Freely Available from IEEE
  • FastDu: Efficient directory summaries harvest by tracking file system changes

    Publication Year: 2011, Page(s):337 - 343
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (458 KB)

    FastDu is a file system service that tracks file system changes by intercepting file system calls to maintain directory summaries, which play important roles in both storage administration and improvement of user experiences for some applications. In most circumstances, directory summaries are independently harvested by applications via traversing the file system hierarchy and calling stat 0 on ev... View full abstract»

    Open Access
  • Mixed H2H control using a fuzzy singularly perturbed model with multiple perturbation parameters for gust load alleviation

    Publication Year: 2011, Page(s):344 - 351
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (592 KB)

    This paper presents a mixed H2H control using fuzzy singularly perturbed model (FSPM) with multiple perturbation parameters. Since FSPM with multiple perturbation parameters is an extension of models with a single perturbation parameter, the theoretical results are applicable to a larger class of systems described by multiple time scale nonlinear models, such as flyin... View full abstract»

    Open Access
  • Dual energy CT imaging in cone-beam micro-CT for improved attenuation coefficient measurement

    Publication Year: 2011, Page(s):352 - 357
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1543 KB)

    In order to improve micro-CT's capability of accurate quantification of linear attenuation coefficient μ, a dual energy method was developed to correct beam hardening artifacts caused by the polychromatic spectra of X-ray tubes. In this method, two sets of scans, taken at different energy levels, were combined to create a synthetic monochromatic image. A physical polychromatic model of �... View full abstract»

    Open Access
  • Reverse detection based QoS routing algorithm for LEO satellite constellation networks

    Publication Year: 2011, Page(s):358 - 363
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1035 KB)

    A reverse detection based OoS routing algorithm was developed based on the dynamic topology of low earth orbit (LEO) satellite constellation networks. This distributed algorithm has very low computational complexity, so it is suitable for on-board processing. This algorithm improves the autonomous operating capability and throughput of satellite networks. Simulations show that the algorithm has be... View full abstract»

    Open Access
  • Radar phase-modulated waveform design for extended target detection

    Publication Year: 2011, Page(s):364 - 370
    Cited by:  Papers (1)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (534 KB)

    Extended target detection performance can be enhanced by using phase-modulated waveform designs in band-limited radar systems. Unlike waveforms designed for the total energy constraint, phase-modulated waveforms can fully exploit the transmit power in the pulse duration, which is more suitable for practical radar systems. An alternating iterative algorithm was developed to optimize the phase-modul... View full abstract»

    Open Access
  • Channel capacity estimation in TDMS-based MIMO measurements

    Publication Year: 2011, Page(s):371 - 376
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1958 KB)

    Time-division multiplexed switching (TOMS)-based multiple-input multiple-output (MIMO) channel sounders are widely used for wireless channel measurements due to their effective costs. However, measurement noise such as phase noise in the local oscillators as well as additive white Gaussian noise (AWGN) can result in significant errors in channel capacity estimates. This study analyzes the impact o... View full abstract»

    Open Access
  • Online metric learning for relevance feedback in e-commerce image retrieval applications

    Publication Year: 2011, Page(s):377 - 385
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (839 KB)

    Relevance feedback plays a key role in multiple feature-based image retrieval applications. This paper describes an online metric learning approach for a set of ranking functions. In the feedback round, the most relevant and most nonrelevant images related to the target image are selected to construct a relative comparison triplet. The weighting parameters of the multiple ranking functions are upd... View full abstract»

    Open Access
  • Cooperative spectrum sensing algorithms based on correlation matrix in cognitive radio networks

    Publication Year: 2011, Page(s):386 - 392
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (572 KB)

    Cooperative energy spectrum sensing has been widely applied in cognitive radio (CR) networks. In this paper, two cooperative sensing algorithms based on the received signals' correlation matrix were proposed. The first proposed algorithm made use of both diagonal elements and non-diagonal elements in the cooperative scheme. In the second algorithm, when the sensing station can obtain the informati... View full abstract»

    Open Access
  • Optimizing a parallel video encoder with message passing and a shared memory architecture

    Publication Year: 2011, Page(s):393 - 398
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (484 KB)

    Implementing video applications on emerging multi-core processors is a promising technique for personal, real-time multi-media applications. However, when porting the legacy parallel video encoders developed for clusters to shared-memory multi-cores, the existing parallel algorithms result in workload imbalances on different cores and communication inefficiencies. This paper describes a strip-wise... View full abstract»

    Open Access
  • Probabilistic delay fault model for DVFS circuits

    Publication Year: 2011, Page(s):399 - 407
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1346 KB)

    Decreasing the power supply voltage in dynamic voltage frequency scaling to save power consumption may introduce extra delays in CMOS circuits, which may cause errors. This paper presents the probabilistic delay fault model (PDFM), which describes the probability of an error occurring as a function of the power supply voltage and the clock period in synchronous CMOS circuits. In a wide range of ap... View full abstract»

    Open Access
  • Development of a BGA package based on Si interposer with through silicon via

    Publication Year: 2011, Page(s):408 - 413
    Cited by:  Papers (3)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (3672 KB)

    A ball grid array (BGA) package based on Si interposer with through silicon via (TSV) was designed. Thermal behaviors of the designed BGA with Si interposer has been analyzed and compared to a conventional BGA with BT substrate in the approach of finite element modeling (FEM). The Si interposer with TSV was then fabricated and the designed BGA package was demonstrated. The designed BGA package inc... View full abstract»

    Open Access
  • Feature rescaling of support vector machines

    Publication Year: 2011, Page(s):414 - 421
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1595 KB)

    Support vector machines (SVMs) have widespread use in various classification problems. Although SVMs are often used as an off-the-shelf tool, there are still some important issues which require improvement, such as feature rescaling. Standardization is the most commonly used feature rescaling method. However, standardization does not always improve classification accuracy. This paper describes two... View full abstract»

    Open Access
  • Accelerating application identification with two-stage matching and pre-classification

    Publication Year: 2011, Page(s):422 - 431
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (612 KB)

    Modern datacenter and enterprise networks require application identification to enable granular traffic control that either improves data transfer rates or ensures network security. Providing application visibility as a core network function is challenging due to its performance requirements, including high throughput, low memory usage, and high identification accuracy. This paper presents a paylo... View full abstract»

    Open Access
  • High-performance packet classification on multi-core network processing platforms

    Publication Year: 2011, Page(s):432 - 439
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1230 KB)

    Packet classification is crucial to the implementation of advanced network services that require the capability to distinguish traffic in different flows, such as access control in firewalls and protocol analysis in intrusion detection systems. This paper proposes a novel packet classification algorithm optimized for multi-core network processors. The proposed algorithm, AggreCuts, has an explicit... View full abstract»

    Open Access
  • Performance improvement of distributed systems by autotuning of the configuration parameters

    Publication Year: 2011, Page(s):440 - 448
    Cited by:  Papers (2)
    IEEE is not the copyright holder of this material | Click to expandAbstract | PDF file iconPDF (1028 KB)

    The performance of distributed computing systems is partially dependent on configuration parameters recorded in configuration files. Evolutionary strategies, with their ability to have a global view of the structural information, have been shown to effectively improve performance. However, most of these methods consume too much measurement time. This paper introduces an ordinal optimization based ... View full abstract»

    Open Access

Aims & Scope

Tsinghua Science and Technology (Tsinghua Sci Technol) aims to highlight scientific achievements in computer science, electronic engineering, and other IT fields. Contributions all over the world are welcome.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Professor Jiaguang Sun
School of Software
Tsinghua University
Beijing  100084 China
journal@tsinghua.edu.cn
Phone:86-10-62771385