By Topic

Systems Engineering and Electronics, Journal of

Issue 4 • Date Aug. 2008

Filter Results

Displaying Results 1 - 25 of 37
  • [Front cover]

    Page(s): c1
    Save to Project icon | PDF file iconPDF (1957 KB)  
    Freely Available from IEEE
  • Copyright page

    Page(s): 1
    Save to Project icon | PDF file iconPDF (48 KB)  
    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Instructions for authors

    Page(s): 1
    Save to Project icon | PDF file iconPDF (1261 KB)  
    Freely Available from IEEE
  • Contents

    Page(s): 1 - 2
    Save to Project icon | PDF file iconPDF (111 KB)  
    Freely Available from IEEE
  • Comparison between two concepts of angular glint: General considerations

    Page(s): 635 - 642
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (365 KB)  

    Angular glint can be interpreted as a distortion of the radar echo signal phase front, or alternatively, a tilt of the direction of energy flow from the radial direction. As the complementarities and support of argumentation in our previous work, a general discussion about two concepts of angular glint is made based on electromagnetic theory to demonstrate that these two concepts are equivalent when geometrical optics approximation is used and the receiving antenna is linearly polarized. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Recent progress on space-borne microwave sounder pre-launch calibration technologies in China

    Page(s): 643 - 651
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (183 KB)  

    The development processes and the application achievements of space-borne microwave sounder pre-launch calibration technologies in China are introduced briefly. Then, the general project plan for pre-launch calibration, the latest research achievements on the optimization and development of the microwave wide band calibration targets, emissivity measurement technologies and the system level uncertainty analysis of the laboratory, and the thermal/vacuum microwave sounder calibration system for “FY-3” meteorological satellite are reported, respectively. Finally, the key technological problems of the calibration technologies under researching are analyzed predictively. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Energy-efficient and security-optimized AES hardware design for ubiquitous computing

    Page(s): 652 - 658
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (275 KB)  

    Ubiquitous computing must incorporate a certain level of security. For the severely resource constrained applications, the energy-efficient and small size cryptography algorithm implementation is a critical problem. Hardware implementations of the advanced encryption standard (AES) for authentication and encryption are presented. An energy consumption variable is derived to evaluate low-power design strategies for battery-powered devices. It proves that compact AES architectures fail to optimize the AES hardware energy, whereas reducing invalid switching activities and implementing power-optimized sub-modules are the reasonable methods. Implementations of different substitution box (S-Boxes) structures are presented with 0.25 μm 1.8 V CMOS (complementary metal oxide semiconductor) standard cell library. The comparisons and trade-offs among area, security, and power are explored. The experimental results show that Galois field composite S-Boxes have smaller size and highest security but consume considerably more power, whereas decoder-switch-encoder S-Boxes have the best power characteristics with disadvantages in terms of size and security. The combination of these two type S-Boxes instead of homogeneous S-Boxes in AES circuit will lead to optimal schemes. The technique of latch-dividing data path is analyzed, and the quantitative simulation results demonstrate that this approach diminishes the glitches effectively at a very low hardware cost. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Grey systems for intelligent sensors and information processing

    Page(s): 659 - 665
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (282 KB)  

    In a measurement system, new representation methods are necessary to maintain the uncertainty and to supply more powerful ability for reasoning and transformation between numerical system and symbolic system. A grey measurement system is discussed from the point of view of intelligent sensors and incomplete information processing compared with a numerical and symbolized measurement system. The methods of grey representation and information processing are proposed for data collection and reasoning. As a case study, multi-ultrasonic sensor systems are demonstrated to verify the effectiveness of the proposed methods. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Volterra series based predistortion for broadband RF power amplifiers with memory effects

    Page(s): 666 - 671
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (303 KB)  

    RF power amplifiers (PAs) are usually considered as memoryless devices in most existing predistortion techniques. However, in broadband communication systems, such as WCDMA, the PA memory effects are significant, and memory less predistortion cannot linearize the PAs effectively. After analyzing the PA memory effects, a novel predistortion method based on the simplified Volterra series is proposed to linearize broadband RF PAs with memory effects. The indirect learning architecture is adopted to design the predistortion scheme and the recursive least squares algorithm with forgetting factor is applied to identify the parameters of the predistorter. Simulation results show that the proposed predistortion method can compensate the nonlinear distortion and memory effects of broadband RF PAs effectively. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Periodic performance of the chaotic spread spectrum sequence on finite precision

    Page(s): 672 - 678
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (252 KB)  

    It is well known that the periodic performance of spread spectrum sequence heavily affects the correlative and secure characteristics of communication systems. The chaotic binary sequence is paid more and more attention since it is one kind of applicable spread spectrum sequences. However, there are unavoidable short cyclic problems for chaotic binary sequences in finite precision. The chaotic binary sequence generating methods are studied first. Then the short cyclic behavior of the chaotic sequences is analyzed in detail, which are generated by quantification approaches with finite word-length. At the same time, a chaotic similar function is defined for presenting the cyclic characteristics of the sequences. Based on these efforts, an improved method with scrambling control for generating chaotic binary sequences is proposed. To quantitatively describe the improvement of periodic performance of the sequences, an orthogonal estimator is also defined. Some simulating results are provided. From the theoretical deduction and the experimental results, it is concluded that the proposed method can effectively increase the period and raise the complexity of the chaotic sequences to some extent. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Analysis for MIMO correlated frequency-selective channel in the presence of interference

    Page(s): 679 - 682
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (389 KB)  

    The space time spreading, superimposed training sequences, and space-time coding are used to present a multiple input and multiple output (MIMO) systems model, and a closed-form of average error probability upper bound expression for MIMO correlated frequency-selective channel in the presence of interference (co-channel interference and jamming signals) is derived. Moreover, the correlation at both ends of the wireless link that can be incorporated equivalently into correlation at the transmit end is also derived, which is significant to analyze space-time link algorithm of MIMO systems. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Improved algorithm of atmospheric refraction error in Longley-Rice channel model

    Page(s): 683 - 687
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (278 KB)  

    Longley-Rice channel model modifies the atmospheric refraction by the equivalent earth radius method, which is simple calculation but is not accurate. As it only uses the horizontal difference, but does not make use of the vertical section information, it does not agree with the actual propagation path. The atmospheric refraction error correction method of the Longley-Rice channel model has been improved. The improved method makes use of the vertical section information sufficiently and maps the distance between the receiver and transmitter to the radio wave propagation distance. It can exactly reflect the infection of propagation distance for the radio wave propagation loss. It is predicted to be more close to the experimental results by simulation in comparison with the measured data. The effectiveness of improved methods is proved by simulation. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Deconvolution techniques for characterizing indoor UWB wireless channel

    Page(s): 688 - 693
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (301 KB)  

    A deconvolution algorithm is proposed to account for the distortions of impulse shape introduced by propagation process. By finding the best correlation of the received waveform with the multiple templates, the number of multipath components is reduced as the result of eliminating the “phantom paths”, and the captured energy increases. Moreover, it needs only a single reference measurement in real measurement environment (do not need the anechoic chamber), which by far simplifies the templates acquiring procedure. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Design and simulation of a Torus topology for network on chip

    Page(s): 694 - 701
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (415 KB)  

    Aiming at the applications of NOC (network on chip) technology in rising scale and complexity on chip systems, a Torus structure and corresponding route algorithm for NOC is proposed. This Torus structure improves traditional Torus topology and redefines the denotations of the routers. Through redefining the router denotations and changing the original router locations, the Torus structure for NOC application is reconstructed. On the basis of this structure, a dead-lock and live-lock free route algorithm is designed according to dimension increase. System C is used to implement this structure and the route algorithm is simulated. In the four different traffic patterns, average, hotspot 13%, hotspot 67% and transpose, the average delay and normalization throughput of this Torus structure are evaluated. Then, the performance of delay and throughput between this Torus and Mesh structure is compared. The results indicate that this Torus structure is more suitable for NOC applications. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Research on the self-defence electronic jamming decision-making based on the discrete dynamic Bayesian network

    Page(s): 702 - 708
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (253 KB)  

    The manner and conditions of running the decision-making system with self-defense electronic jamming are given. After proposing the scenario of applying discrete dynamic Bayesian network to the decision making with self-defense electronic jamming, a decision-making model with self-defense electronic jamming based on the discrete dynamic Bayesian network is established. Then jamming decision inferences by the aid of the algorithm of discrete dynamic Bayesian network are carried on. The simulating result shows that this method is able to synthesize different targets which are not predominant. In this way, various features at the same time, as well as the same feature appearing at different time complement mutually; in addition, the accuracy and reliability of electronic jamming decision making are enhanced significantly. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Super-resolution processing of passive millimeter-wave images based on adaptive projected Landweber algorithm

    Page(s): 709 - 716
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (354 KB)  

    Passive millimeter wave (PMMW) images inherently have the problem of poor resolution owing to limited aperture dimension. Thus, efficient post-processing is necessary to achieve resolution improvement. An adaptive projected Landweber (APL) super-resolution algorithm using a spectral correction procedure, which attempts to combine the strong points of all of the projected Landweber (PL) iteration and the adaptive relaxation parameter adjustment and the spectral correction method, is proposed. In the algorithm, the PL iterations are implemented as the main image restoration scheme and a spectral correction method is included in which the calculated spectrum within the passband is replaced by the known low frequency component. Then, the algorithm updates the relaxation parameter adaptively at each iteration. A qualitative evaluation of this algorithm is performed with simulated data as well as actual radiometer image captured by 91.5 GHz mechanically scanned radiometer. From experiments, it is found that the super-resolution algorithm obtains better results and enhances the resolution and has lower mean square error (MSE). These constraints and adaptive character and spectral correction procedures speed up the convergence of the Landweber algorithm and reduce the ringing effects that are caused by regularizing the image restoration problem. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Cauchy pdf modelling and its application to SAR image despeckling

    Page(s): 717 - 721
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (290 KB)  

    Synthetic aperture radar (SAR) imagery is a kind of coherent system that produces a random pattern, named speckle, which degrades the merit of SAR images and affects their further application seriously. Therefore, how to restore SAR image from the speckle has become a necessary step in post-processing of image. A new despeckling method is putforth on the basis of wavelet. First, a new approach on the basis of “second kind statistics” is used to estimate the dispersion parameter of the Cauchy distribution. Then, this Cauchy prior is applied to model the distribution of the wavelet coefficients for the log-transformed reflectance of SAR image. Based on the above ideas, a new homomorphic wavelet-based maximum a posterior (MAP) despeckling method is proposed. Finally, the simulated speckled image and the real SAR image are used to verify our proposed method and the results show that it outperforms the other methods in terms of the speckle reduction and the feature retention. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New coordination scheme for multi-robot systems based on state space models

    Page(s): 722 - 734
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (469 KB)  

    A new coordination scheme for multi-robot systems is proposed. A state space model of the multi-robot system is defined and constructed in which the system's initial and goal states are included along with the task definition and the system's internal and external constraints. Task accomplishment is considered a transition of the system state in its state space (SS) under the system's constraints. Therefore, if there exists a connectable path within reachable area of the SS from the initial state to the goal state, the task is realizable. The optimal strategy for the task realization under constraints is investigated and reached by searching for the optimal state transition trajectory of the robot system in the SS. Moreover, if there is no connectable path, which means the task cannot be performed successfully, the task could be transformed to be realizable by making the initial state and the goal state connectable and finding a path connecting them in the system's SS. This might be done via adjusting the system's configuration and/or task constraints. Experiments of multi-robot formation control with obstacles in the environment are conducted and simulation results show the validity of the proposed method. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Algorithms for degree-constrained Euclidean Steiner minimal tree

    Page(s): 735 - 741
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (209 KB)  

    A new problem of degree-constrained Euclidean Steiner minimal tree is discussed, which is quite useful in several fields. Although it is slightly different from the traditional degree-constrained minimal spanning tree, it is also NP-hard. Two intelligent algorithms are proposed in an attempt to solve this difficult problem. Series of numerical examples are tested, which demonstrate that the algorithms also work well in practice. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Application of rough graph in relationship mining

    Page(s): 742 - 747
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (251 KB)  

    Based on the definition of class shortest path in weighted rough graph, class shortest path algorithm in weighted rough graph is presented, which extends classical shortest path algorithm. The application in relationship mining shows effectiveness of it. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • New model for load-sharing k-out-of-n: G system with different components

    Page(s): 748 - 751
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (194 KB)  

    On the basis of capacity flow model, a new model is developed for a load-sharing k-out-of-n: G system consisting of different components, to describe the increase of the same component's failure rates under different loads. All components have exponential life distributions and are nonrepairable in the system. Reliability of load-sharing 2-out-of-3: G system is calculated and some special cases for the system are discussed. The calculation and discussions show that the model is right and practical. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Singularly perturbed bifurcation subsystem and its application in power systems

    Page(s): 752 - 757
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (84 KB)  

    The singularly perturbed bifurcation subsystem is described, and the test conditions of subsystem persistence are deduced. By use of fast and slow reduced subsystem model, the result does not require performing nonlinear transformation. Moreover, it is shown and proved that the persistence of the periodic orbits for Hopf bifurcation in the reduced model through center manifold. Van der Pol oscillator circuit is given to illustrate the persistence of bifurcation subsystems with the full dynamic system. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Delay-dependent state feedback robust stabilization for uncertain singular time-delay systems

    Page(s): 758 - 765
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (339 KB)  

    The problem of robust stabilization for uncertain singular time-delay systems is studied. First, a new delay-dependent asymptotic stability criteria for normal singular time-delay systems is given, which is less conservative. Using this result, the problem of state feedback robust stabilization for uncertain singular time-delay systems is discussed. Finally, two examples are given to illustrate the effectiveness of the results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Delay-dependent decentralized H filtering for uncertain interconnected systems

    Page(s): 766 - 774
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (398 KB)  

    This article considers delay dependent decentralized H filtering for a class of uncertain interconnected systems, where the uncertainties are assumed to be time varying and satisfy the norm-bounded conditions. First, combining the Lyapunov-Krasovskii functional approach and the delay integral inequality of matrices, a sufficient condition of the existence of the robust decentralized H filter is derived, which makes the error systems asymptotically stable and satisfies the H norm of the transfer function from noise input to error output less than the specified up-bound on the basis of the form of uncertainties. Then, the above sufficient condition is transformed to a system of easily solvable LMIs via a series of equivalent transformation. Finally, the numerical simulation shows the efficiency of the main results. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.
  • Study of the control-equilibrium of control systems

    Page(s): 775 - 778
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (116 KB)  

    Not so much had been talked about equilibrium in control area. On the basis of the phenomenon of balance, the concept of control-equilibrium and control-equilibrium of a control system is proposed. According to this theory, a perfect control method should not only guarantee stability of the system, but also ensure the control-equilibrium of the system. To achieve the control-equilibrium, feed-forward control is required. View full abstract»

    Full text access may be available. Click article title to sign in or learn about subscription options.

Aims & Scope

Journal of Systems Engineering and Electronics reports the latest developments and achievements in both theoretical and practical aspects of systems engineering, electronics and related research areas.

Full Aims & Scope

Meet Our Editors

Editor-in-Chief
Professor Rong Shi
Journal of Systems Engineering and Electronics