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271.
Keith Warren Julien C. Sprott Raymond C. Hawkins 《Nonlinear dynamics, psychology, and life sciences》2002,6(1):55-70
In recent years there has been considerable interest in the construction of nonlinear models of the dynamics of human behavior. In this exploratory article we argue that attempts at controlling problematic thoughts, emotions, or behaviors can lead to nonlinearity in mental/behavioral dynamics. We illustrate our model by fitting threshold autoregression models to self-recorded time series of the daily highs in intensity of anxiety and obsessive ruminations, kept by an individual in therapy for this problem. In our discussion, we raise the possibility that bifurcations that occur in this nonlinear model may offer insight into mental control paradoxes. 相似文献
272.
对四分块矩阵A=A(︿) A(︿,︿′)A(︿′,︿) A(︿′)来说 ,如果 A和 A(︿)都是非奇异的 ,则A- 1 (︿′) =(A/︿) - 1 ,这里 A/ ︿=A(︿′) -A(︿′,︿) A(︿) - 1 A(︿,︿′)是 A(︿)在 A中的 Schur补 .王伯英教授指出上述等式 ,对半正定的 Hermitian矩阵而言 ,一般也是不能推广到 Moore-Penrose逆上去的 .在某些限制条件下 ,我们证明了广义逆的主子矩阵与广义 Schur补的关系是密切的 ,它使经典结果成为特例 相似文献
273.
K. Naito 《Journal of Optimization Theory and Applications》1989,60(1):57-65
We treat an abstract semilinear control system and study the controllability problem for its trajectories. Assuming a range condition of the control action operator and an inequality condition on the system parameters, we can show that the reachable trajectory set of the semilinear system is equivalent to that of its corresponding linear system.The author wishes to express his deep appreciation to Prof. T. I. Seidman for his many helpful suggestions and to Prof. W. Takahashi for many stimulating conversations. 相似文献
274.
基于像素特征的路面裂缝图像自适应滤噪 总被引:1,自引:1,他引:0
朱其刚 《山东师范大学学报(自然科学版)》2005,20(3):37-39
分析了破损路面图像的像素点区域特征,针对不同区域提出加权邻域滤波和自适加权中值滤波算法。其权值是通过对图像中区域特征的推理得到的,所以算法中能根据图像的区域特征自适应的进行滤波。试验表明,本算法能够有效滤除噪声,并具有很好的细节保护能力。 相似文献
275.
最优受教育年限选择的模型分析 总被引:2,自引:1,他引:1
为进一步定量分析个人教育投资现象,构建了一般性地反映人们在就学和就业之间进行选择的最优化模型,并对影响人们教育投资决策行为的因素进行了分析.在简单的假定前提下运用数学语言再现了教育经济和劳动经济研究中的相关结论. 相似文献
276.
We apply the least‐squares finite element method with adaptive grid to nonlinear time‐dependent PDEs with shocks. The least‐squares finite element method is also used in applying the deformation method to generate the adaptive moving grids. The effectiveness of this method is demonstrated by solving a Burgers' equation with shocks. Computational results on uniform grids and adaptive grids are compared for the purpose of evaluation. The results show that the adaptive grids can capture the shock more sharply with significantly less computational time. For moving shock, the adaptive grid moves correctly with the shock. © 2005 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2006 相似文献
277.
COSEARCH: A Parallel Cooperative Metaheuristic 总被引:1,自引:0,他引:1
In order to design a well-balanced metaheuristic for robustness, we propose the COSEARCH approach which manages the cooperation
of complementary heuristic methods via an adaptive memory which contains a history of the search already done. In this paper,
we present the idiosyncrasies of the COSEARCH approach and its application for solving large scale instances of the quadratic
assignment problem (QAP). We propose an original design of the adaptive memory in order to focus on high quality regions of
the search and avoid attractive but deceptive areas. For the QAP, we have hybridized three heuristic agents of complementary
behaviours: a Tabu Search is used as the main search algorithm, a Genetic Algorithm is in charge of the diversification and
a Kick Operator is applied to intensify the search. The evaluations have been executed on large scale network of workstations
via a parallel environment which supports fault tolerance and adaptive dynamic scheduling of tasks. 相似文献
278.
一种结合了基于任务的访问控制模型TBAC和基于角色的访问控制模型RBAC特点的新型访问控制模型-T-RBAC.该模型采用了以任务为中心的"用户-角色-任务-权限"的四级访问控制结构,较好地解决了当前工作流系统中存在的安全性问题.此外,在新模型的基础上设计了一套描述约束机制的语言ETCL,该语言在RCL2000的基础上扩充了时间特性和任务的概念,使新模型具备了较完整的约束描述能力. 相似文献
279.
After the laser was invented in 1960, a phase conjugation mirror has been respected to be the most fantastic one for the laser
resonator composition because it can compensate any distortions of the laser beams occurred by the many inhomogenuities of
the laser media and optical components. Among the many phase conjugation configurations, the stimulated Brillouin scattering
phase conjugation mirror is the most simple one and many researchers have tried to utilize it to develop high power/energy
laser systems. For realizing a high energy/power laser system the thermal problem is the most difficult to solve, and some
researchers suggested a beam combination technique to reduce the thermal load of the big laser media to many small sized ones.
To accomplish the beam combination using stimulated Brillouin scattering phase conjugation mirrors (SBS-PCMs), it is necessary
to lock/control the phases of the SBS-PCMs. And some researchers have developed several ways for it, but they can lock the
phases of a limited number of beams overlapped at the foci less than 5, or lock the phases by back-seeding technique but it
loses the phase conjugation characteristics. For realization of the laser fusion driver, it is necessary to combine more than
10 or 100 beams. And the authors have developed recently a new phase controlling/locking technique which is isolated and independent
totally from other beams and it can be applied to an unlimited number of beams in principle. 相似文献
280.
本文用另一方法证明了非对称矩阵的奇异值是处处强半光滑的,并利用这一性质给出求解逆奇异值问题的相对广义牛顿法,该方法具有Q-二阶收敛速度. 相似文献