中国科学院数学与系统科学研究院期刊网

2008年, 第21卷, 第1期 刊出日期:2008-03-20
  

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  • Lean YU;Shouyang WANG;Kin Keung LAI
    Journal of Systems Science and Complexity. 2008, 21(1): 1-019.
    摘要 ( ) PDF全文 ( )   可视化   收藏
    Due to the complexity of economic system and the interactive effects between all kinds of economic variables and foreign trade, it is not easy to predict foreign trade volume. However, the difficulty in predicting foreign trade volume is usually attributed to the limitation of many conventional forecasting models. To improve the prediction performance, the study proposes a novel kernel-based ensemble learning approach hybridizing econometric models and artificial intelligence (AI) models to predict China's foreign trade volume. In the proposed approach, an important econometric model, the co-integration-based error correction vector
    auto-regression (EC-VAR) model is first used to capture the impacts of all kinds of economic variables on Chinese foreign trade from a multivariate linear analysis perspective. Then an artificial neural network (ANN) based EC-VAR model is used to capture the nonlinear effects of economic variables on foreign trade from the nonlinear viewpoint. Subsequently, for incorporating the effects of irregular
    events on foreign trade, the text mining and expert's judgmental adjustments are also integrated into the nonlinear ANN-based EC-VAR model. Finally, all kinds of economic variables, the outputs of linear and nonlinear EC-VAR models and judgmental adjustment model are used as input variables of a typical kernel-based support vector regression (SVR) for ensemble prediction purpose. For illustration,
    the proposed kernel-based ensemble learning methodology hybridizing econometric techniques and AI methods is applied to China's foreign trade volume prediction problem. Experimental results reveal that the hybrid econometric-AI ensemble learning approach can significantly improve the prediction performance over other linear and nonlinear models listed in this study.
  • Liang CHEN;Jun'an LU
    Journal of Systems Science and Complexity. 2008, 21(1): 20-033.
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    This paper further investigates cluster synchronization in a complex dynamical network with two-cluster. Each cluster contains a number of identical dynamical systems, however, the sub-systems composing the two clusters can be different, i.e., the individual dynamical system in one cluster can differ from that in the other cluster. Complete synchronization within each cluster is possible only if each node from one cluster receives the same input from nodes in other cluster. In this case, the stability condition of one-cluster synchronization is known to contain two terms: the first accounts for the contribution of the inner-cluster coupling structure while
    the second is simply an extra linear term, which can be deduced by the ``same-input'' condition. Applying the connection graph stability method, the authors obtain an upper bound of input strength for one cluster if the first account is known, by which the synchronizability of cluster can be scaled. For different clusters, there are different upper bound of input strength by virtue of different dynamics and the corresponding cluster structure. Moreover, two illustrative examples are presented and the numerical simulations coincide with the theoretical analysis.
  • Xijin TANG;Nan ZHANG;Zheng WANG
    Journal of Systems Science and Complexity. 2008, 21(1): 34-045.
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    Traditional Chinese medicine (TCM) has a rich knowledge about human health and disease by its special way evolved along a very long history. As modern medicine is achieving much progress, arguments and disputes toward TCM never end. To avoid losing precious knowledge of living TCM masters, endeavors have been engaged to systematic collection of those knowledge of TCM masters, such as their growth experiences, effective practical cases toward diseases and typical therapeutic principles and methods. Knowledge mining methods have been expected to explore some useful or hidden patterns to unveil some mysteries of the TCM system. In the paper, some computerized methods are applied toward those collected materials about some living TCM masters in China mainland to show a different way of exposing essential ideas of those TCM masters by correspondence visualization which aims to help people understand TCM holistic views toward disease and body, and facilitate tacit knowledge transfer and sense-making of the essence of TCM. The work is one kind of qualitative meta-synthesis of TCM masters' knowledge.
  • Hongguo ZHAO;Huanshui ZHANG;Hongxia WANG;Chenghui ZHANG
    Journal of Systems Science and Complexity. 2008, 21(1): 46-059.
    摘要 ( ) PDF全文 ( )   可视化   收藏
    The infinite-horizon linear quadratic regulation (LQR) problem is settled for discrete-time systems with input delay. With the help of an autoregressive moving average (ARMA)innovation model, solutions to the underlying problem are obtained. The design of the optimal control law involves in resolving one polynomial equation and one spectral factorization.The latter is the major obstacle of the present problem, and the reorganized innovation approach is used to clear it up. The calculation of spectral factorization finally comes down to solving two Riccati equations with the same dimension as the original systems.
  • Shixin ZHU;Xiaoshan KAI
    Journal of Systems Science and Complexity. 2008, 21(1): 60-066.
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    The Hamming distances of all negacyclic codes of length $2^s$ over the Galois ring $GR\left( {2^a,m} \right)$ are given. In particular, the Lee distances of all negacyclic codes over $Z_4 $ of length $2^s$ are obtained. The Gray images of such negacyclic codes over $Z_4 $ are also determined under the Gray map.
  • Zeraoulia ELHADJ
    Journal of Systems Science and Complexity. 2008, 21(1): 67-075.
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    The paper reports the dynamical study of a three-dimensional quadratic utonomous chaotic system with only two quadratic nonlinearities, which is a special case of the so-called conjugate L\"{u} system. Basic properties of this system are analyzed by means of Lyapunov exponent spectrum and bifurcation diagram. The analysis
    shows that the system has complex dynamics with some interesting characteristics in which there are several periodic regions, but each of them has quite different periodic orbits.
  • Xiwang CAO
    Journal of Systems Science and Complexity. 2008, 21(1): 76-084.
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    Sequences with ideal correlation functions have important applications in communications such as CDMA, FDMA, etc. It has been shown that difference sets can be used to construct such sequences. The author extends Pott and Bradley's method to a much broader case by proposing the concept of generalized difference sets. Some necessary conditions for the existence of generalized difference sets are established by means of some Diophantine equations. The author also provides an algorithm to determine the existence of generalized difference sets in the cyclic group $\mathbb{Z}_v$. Some examples are presented to illustrate that our method works.
  • Peihua GUO;Detong ZHU
    Journal of Systems Science and Complexity. 2008, 21(1): 85-113.
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    The authors propose an affine scaling modified gradient path method in association with reduced projective Hessian and nonmonotonic interior backtracking line search techniques for solving the linear equality constrained optimization subject to bounds on variables. By employing the QR decomposition of the constraint matrix and the eigensystem decomposition of reduced projective Hessian matrix in
    the subproblem, the authors form affine scaling modified gradient curvilinear path very easily. By using interior backtracking line search technique, each iterate switches to trial step of strict interior feasibility. The global convergence and fast local superlinear/quadratical convergence rates of the proposed algorithm are established under some reasonable conditions. A nonmonotonic criterion should bring about speeding up the convergence progress in some ill-conditioned cases. The results of numerical experiments are reported to show the effectiveness of
    the proposed algorithm.
  • Shoupeng LIU;Yuzhong ZHANG
    Journal of Systems Science and Complexity. 2008, 21(1): 114-118.
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    The authors consider the problem of on-line scheduling of unit execution time jobs on uniform machines with rejection penalty. The jobs arrive one by one and can
    be either accepted and scheduled, or be rejected. The objective is to minimize the total completion time of the accepted jobs and the total penalty of the rejection jobs. The authors propose an on-line algorithm and prove that the competitive
    ratio is $\frac{1}{2}(2+\sqrt{3})\approx1.86602$.
  • Jiaqi MO;Wantao LIN
    Journal of Systems Science and Complexity. 2008, 21(1): 119-128.
    摘要 ( ) PDF全文 ( )   可视化   收藏
    A nonlinear reaction diffusion equations for activator inhibitor systems is considered. Under suitable conditions, firstly, the outer solution of the original problem is obtained, secondly, using the variables of multiple scales and the expanding theory of power series the formal asymptotic expansions of the solution are constructed, and finally, using the theory of differential inequalities the uniform validity and asymptotic behavior of the solution are studied.
  • Min Yang
    Journal of Systems Science and Complexity. 2008, 21(1): 129-143.
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    The author considers a thermal convection problem with infinite Prandtl number in two or three dimensions. The mathematical model of such problem is described as an initial boundary value problem made up of three partial differential equations. One equation of the convection-dominated diffusion type for the temperature, and another two of the Stokes type for the normalized velocity and pressure. The approximate solution is obtained by a penalty finite volume method for the Stokes equation and a multistep upwind finite volume method for the convection-diffusion equation. Under suitable smoothness of the exact solution, error estimates in some discrete norms are derived.
  • Xueliang MA;Jianming ZHAN
    Journal of Systems Science and Complexity. 2008, 21(1): 144-158.
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    The authors introduce the notions of $(\in,\in\vee q)$-fuzzy Boolean (implicative, positive implicative, and fantastic) filters in $BL$-algebras, present some haracterizations on these generalized fuzzy filters, and describe the
    relations among these generalized fuzzy filters. It is proved that an $(\in,\in\vee q)$-fuzzy filter in a $BL$-algebra is Boolean (implicative) if and only if it is both positive implicative and fantastic.