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Systems Engineering and Electronics, Journal of

Issue 3 • Date Sept. 2003

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Displaying Results 1 - 21 of 21
  • [Front cover]

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    Freely Available from IEEE
  • Copyright page

    Page(s): 1
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  • Contents

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  • Equivalent time-domain representation and uplink channel estimator for multicarrier CDMA systems

    Page(s): 1 - 7
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1217 KB)  

    Many blind channel estimation methods have been proposed for direct sequence (DS) code-division multiple access (CDMA) systems, so we can certainly use them to estimate the finite impulse response (FIR) channel for the multicarrier (MC-) CDMA system. In this paper, the MC-CDMA system is interpreted as an equivalent time-domain DS-CDMA system with specific spreading codes. Then, an equivalently time-domain blind channel estimator is derived for the uplink MC-CDMA, which is based on second-order statistics of the received data. By exploiting singular value decomposition (SVD) and the finite alphabet property of transmitted symbols. the time-domain channel impulse response (CIR) for the uplink MC-CDMA can be accurately identified. Computer simulations illustrate both the validity and the overall performance of the proposed estimator. View full abstract»

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  • New method for constructing comparison matrix based on the proportion scales in the AHP

    Page(s): 8 - 13
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    The main faults existing in current scale methods are that the scales do not represent the real importance of altrematives and their relations. This paper presents a proportion judgment scale and introduces a new method based on the proportion scale for construction comparison matrix in the analytic hierarchy process (AHP). The proportion judgment scales do not have the faults existing in current scale methods and the comparison matrix constructed by the new scale method does not need any consistency checking because it is always consistent. Not only can it greatly enhance the reliability and efficiency of decision-making of AHP but also make AHP more simple and convenient in practical use. View full abstract»

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  • FL-FN-MOGA based traffic signal control

    Page(s): 14 - 23
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (2047 KB)  

    In this paper, a traffic signal control method based on fuzzy logic (FL), fuzzy-neuro (FN) and multi-objective genetic algorithms (MOGA) for an isolated four-approach intersection with through and left-turning movements is presenred. This method has an adaptive signal timing ability, and can make adjustments to signal timing in response to observed changes. The “urgency degree” term, which can describe the different user's demand for green time is used in decision-making by which strategy of signal timing can be determined. Using a fuzzy logic controller, we can determine whether to extend or terminate the current signal phase and select the sequences of phases. In this paper, a method based on fuzzy-neuro can be used to predict traffic parameters used in fuzzy logic controller. The feasibility of using a multi-objective genetic algorithm (MOGA) to find a group of optimizing sets of parameters for fuzzy logic controller depending on different objects is also demonstrated. Simulation results show that the proposed methed is effecfive to adjust the signal timing in response to changing traffic conditions on a real-time basis, and the controller can produce lower vehicle delays and percentage of stopped vehicles than a traffic-actuated controller. View full abstract»

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  • Finding the minimum ratio traveling salesman tour by artificial ants

    Page(s): 24 - 27
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    Ants of artificial colony are able to generate good solutions to the famous traveling salesman problem (TSP). We propose an artificial ants algorithm for solving the minimum ratio TSP, which is more general than the standard TSP in combinatorial optimization area. In the minimum ratio TSP, another criterion concerning each edge is added, that is, the traveling salesman can have a benefit if he travels from one city to another. The objective is to minimize the ratio between total costs or distances and total benefits. The idea of this type of optimization is in some sense quite similar to that of traditional cost-benefit analysis in management science. Computational results substantiate the solution quality and efficiency of the algorithm. View full abstract»

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  • Performance analysis of the dynamic CSMA/CD protocol in a wireless channel

    Page(s): 28 - 32
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    In wireless networks, packet access is a popular mode and the key problem is how to improve throughput and access delay performance, especially the throughput for wireless channels. These results will be a reference for not only a wireless channel but also a common MAC protocol. View full abstract»

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  • Performance of MC-CDMA systems with orthogonal transmit diversity over Rayleigh fading channel

    Page(s): 33 - 39
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    Transmit diversity has been recently proposed to reduce the effects of fading channels in various wireless applications. Orthogonal transmit diersity (OTD) is one of the standardized techniques in 3G systems. In this paper, we apply orthogonal transmit diversity technique to multicarrier CDMA systems. Andlysis and simulation results show that performance benefits can be achieved compared with conventioal MC-CDMA systems in multipath fading channels. View full abstract»

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  • Study on the class-based admission control scheme for DiffServ in MPLS networks

    Page(s): 40 - 44
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (950 KB)  

    Differentiated services (DiffServ) and MPLS are two major building blocks for providing multi-class services over IP networks. In order to respond to the need for relatively simple, coarse methods of providing different levels of service for Internet traffic, to support various types of applications and specific business requirements, the MPLS network infrastructure and the DiffServ traffic model will work together. Meanwhile, in today's environment of multiple service networks, it is necessary for the node in the networks to perform the control mechanism to guarantee various QoS. In this paper, we propose a class-based admission control scheme that is suitable for DiffServ in MPLS networks. This scheme can achieve twofold objects: reliable QoS provisioning and high resource utilization. We evaluate the proposed scheme by numerical analysis of its performance in terms of throughput. delay, and reject probability. By performing simulation, we can ensure that the proposed scheme can work efficiently to provide strict QoS guarantees. View full abstract»

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  • Modulation frequency optimization in two-colar instruments

    Page(s): 45 - 48
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    How to choose modulation frequency in the extra-high frequency geodimeter is directly related to a lot key matters such as distance sensitivity of instruments and degree of technological difficulty of modulation system. This paper analyzes and proves that choice range of modulation frequency can be from 800 MHz up to extra-high frequency with the basically same distance sensitivity. Therefore, in the developing of geodimeter, we can choose the modulation frequency in wide range according to practical situation. This is very convenient and useful in practice. View full abstract»

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  • Efficient calculation of the radar cross section at the interior resonance by the inverse power method

    Page(s): 49 - 52
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    It is well known that the incorrect results will be given using either the electric or magnetic field integral equation to calculate the radar cross section (RCS) of a closed body at the interior resonance. In this paper, an effective iterative technique is used to correct the calculated surface current density from the electric field integral equation. The radar cross section is computed for an infinite conducting circular cylinder at the interior resonance, and the obtained results are in good agreement with the analytical results. The backscattering cross section of an infinite triangular cylinder in the vicinity of a resonant frequency is also calculated. It is shown that the presence method is efficient and accurate. View full abstract»

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  • Support vector machine-based nonlinear system modeling and control

    Page(s): 53 - 58
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1164 KB)  

    This paper provides an introduction to a support vector machine, a new kernel-based technique introduced in statistical learning theory and structural risk minimization, then presents a rnodeling-control framework based on SVM, At last a numerical experiment is taken to demonstrate the proposed approach's correctness and effectiveness. View full abstract»

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  • Sliding mode controller design for position and speed control of flight simulator servo system with large friction

    Page(s): 59 - 62
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (706 KB)  

    Flight simulator is an important device and a typical high-performance position and speed servo system used in the hardware-in-the-loop simulation of flight control system. Friction is the main nonlinear resistance in the flight simulator servo system, especially in a low-speed state. Based on the description of dynamic and static models of a nonlinear Stribeck friction model, this paper puts forward sliding mode controller to overcome the friction, whose stability is proved. Simulation example indicates that the controller can guarantee a high robust performance and have a high precision of position tracking and speed tracking for a flight simulator servo system. View full abstract»

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  • Study on robust uniform asymptotical stability for uncertainlinear impulsive delay systems

    Page(s): 63 - 66
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    In the area of control theory the time-delay systems have been investigated. It's well known that delays often result in instability, therefore, stability analysis of time-delay systems is an important subject in control theory. As a result, many criteria for testing the stability of linear time-delay systems have been proposed. Significant progress has been made in the theory of impulsive systems and impulsive delay systems in recent years. However, the corresponding theory for uncertain impulsive systems and uncertain impulsive delay systems has not been fully developed. In this paper, robust stability criteria are established for uncertain linear delay impulsive systems by using Lyapunov function, Razumikhin techniques and the results obtained. Some examples are given to illustrate our theory. View full abstract»

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  • Map building for a mobile robot based on grey system theory

    Page(s): 67 - 72
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    In this paper, a new method for mobile robot map building based on grey system theory is presented, by which interpretation and integration of sonar readings can be solved robustly and efficiently. The conception of “grey number” is introduced to model and handle the uncertainty of sonar reading. A new data fusion approach based on grey system theory is proposed to construct environment model. Map building experiments are performed both on a platform of simulation and a real mobile robot. Experimental results show that our method is robust and accurate. View full abstract»

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  • Face recognition based on support vector machine and nearest neighbor classifier

    Page(s): 73 - 76
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    Support vector machine (SVM), as a novel approach in pattern recognition, has demonstrated a success in face detection and face recognition. In this paper, a face recognition approach based on the SVM classifier with the, nearest neighbor classifier (NNC) is proposed. The principal component analysis (PCA) is used to reduce the dimension and extract features. Then one-against-all stratedy is used to train the SVM classifiers. At the testing stage, we propose an algorithm by combining SVM classifier with NNC to improve the correct recognition rate. We conduct the experiment on the Cambridge ORL face database. The result shows that our approach outperforms the standard eigenface approach and some other approaches. View full abstract»

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  • A novel 2-D signal processing scheme for quasi-random step frequency signal

    Page(s): 77 - 80
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    Due to the heavy congestion in HF bands, HF radars are restricted to operating within narrow frequency bands. To improve the system bandwidth and avoid heavy interference bands, a quasi-random step frequency signal with discontinuous bands is presented. A novel two-dimensional signal processing scheme for this signal is proposed on the basis of delicate signal analysis. Simulation results demonstrate that the scheme could successfully realize the resolutions by decoupling the range-Doppler ambiguity, and effectively suppress the maximal sidelobe. Moreover, the scheme is simple and has good numerical stability. View full abstract»

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  • Building a tax predictive model based on the cloud neural network

    Page(s): 81 - 86
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    Tax is very important to the whole country, so a scientific tax predictive model is needed. This paper introduces the theory of the cloud model. On this basis, it presents a cloud neural network, and analyzes the main factors which influence the tax revenue. Then if proposes a tax predictive model based on the cloud neural network. The model combines the strongpoints of the cloud model and the neural network. The experiment and simulation results show the effectiveness of the algorithm in this paper. View full abstract»

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  • Asymptotic analysis of estimated cyclic cross-correlation function between stationary and cyclostationary processes

    Page(s): 87 - 91
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    The cyclic cross-correlation between a stationary process and a cyclosrationary process at cycle frequency α(≠ 0) is identically zero under an ideal condition, which indicates that a cyclic cross-correlation method performs much better than the conventional cross-correlation method in suppressing the stationary noise orinterference. But unfortunately, the cyclic cross-correlation will not really approach zero due to the limited data length in some real conditions. In this paper, the quantitative relation between the data length and the estimated cyclic cross-correlation is deduced, and some useful conclusions are drawn, which are proven by some computer simulations. The conclusion in this paper is really useful for the practical application of cyclostationary signal processing. View full abstract»

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  • Optimal budget spending for software testing under the condition of nonlinear constraint

    Page(s): 92 - 97
    Save to Project icon | Click to expandQuick Abstract | PDF file iconPDF (1195 KB)  

    Software testing is a very important phase of the software development process. It is a very difficult job for a software manager to allocate optimally the financial budget to a software project during testing. In this paper the problem of optimal allocation of the software testing cost is studied. There exist several models focused on the development of software costs measuring the number of software errors remaining in the software during testing. The purpose of this paper is to use these models to formulate the optimization problems of resource allocation: Minimization of the total number of software errors remaining in the system. On the assumption that a software project consists of some independent modules, the presented approach extends previous work by defining new goal functions and extending the primary assumption and precondition. View full abstract»

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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.

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