Top-Down Query Processing in First-Order Deductive Databases under the DWFS

A top-down query-processing method for first-order deductive databases under the disjunctive well-founded semantics (DWFS) is presented. The method is based on a characterization of the DWFS in terms of the Gelfond–Lifschitz transformation and employs a hyperresolution-like operator and quasi-cyclic trees to handle minimal model processing. The method is correct and complete and can be guaranteed to terminate given certain mild constraints on the format of database rules. The efficiency of the method is enhanced by the fact that large parts of the search tree are naturally grounded, even for first-order queries and databases. In the case of a grounded yes/no answer, the search tree becomes nongrounded only if processing enters the definite part of the database. For finite propositional databases the method runs in polynomial space. Efficiency may be enhanced by the application of partial compilation.     

自适应动态控制种群规模的自然计算方法

提出了一种种群规模自适应动态控制策略,实现了种群规模根据进化过程自适应的动态变化.该策略的实现不依赖于算法进化操作的具体步骤,因而适用于各种基于种群优化的自然计算方法.首先给出了动态控制策略的框架;然后,在此框架下,充分利用动态种群规模反馈的有用信息,提出了基于Logistic模型的增加/删除数目自适应变化的方法,设计了自适应地兼顾有效性和多样性的增加算子和基于多样性的删除算子.将该策略应用到两种不同的自然计算方法中,采用经典测试函数和新型CEC05测试函数验证其性能.实验结果均表明,结合了所提出的种群规模自适应动态控制策略的新算法,比原算法在求解精度和收敛速度上均有明显的提升.     

一种基于遗传算法的进化计算模型

提出一种基于遗传算法的进化计算模型(ECM).在ECM的种群中,每个成员都根据其适应度值不同程度地影响着种群的进化.ECM定义了个体对进化的影响因子,并以个体的影响因子为参数定义了个体的形成算子.分析表明,ECM是采用算术交叉算子的两父辈遗传算法以及采用频率扫描交叉算子的多父辈交叉遗传算法的推广,形成操作是父代群体编码的凸组合.实验研究显示,ECM具有比经典遗传算法更强的优化计算功能.     

基于进化计算的中医脉象分类识别研究

为了实现中医脉象的客观、准确分类,提出了一种基于进化计算的脉象识别方法.提出一种改进的GEP算法(IGEP),并对IGEP算法进行了复杂度分析.基于IGEP,设计出了对脉象信号进行自动建模识别的系统.最后用大量临床脉象样本对算法建模的函数进行了检验,实验结果表明该方法能够实现对中医常见脉象的准确、快速分类.     

A hybrid genetic algorithm to optimize simple distillation column sequences

Based on the principles of Genetic Algorithms (GAs), a hybrid genetic algorithm used to optimize simple distillation column sequences was established. A new data structure, a novel arithmetic crossover operator and a dynamic mutation operator were proposed. Together with the feasibility test of distillation columns, they are capable to obtain the optimum simple column sequence at one time without the limitation of the number of mixture components, ideal or non-ideal mixtures and sloppy or sharp splits. Compared with conventional algorithms, this hybrid genetic algorithm avoids solving complicated nonlinear equations and demands less derivative information and computation time. Result comparison between this genetic algorithm and Underwood method and Doherty method shows that this hybrid genetic algorithm is reliable.     

基于变迁的完全路径覆盖测试

为解决基于状态节点搜索的完全路径覆盖所产生的测试用例数过多和难以实现连续测试的问题,提出了一种基于变迁的完全路径覆盖测试准则,并设计和实现了一种深度优先搜索与宽度优先搜索相结合的基于变迁完全路径覆盖测试用例自动生成算法。实验结果表明,基于变迁的完全路径覆盖准则比基于状态的完全路径覆盖准则更为严格,相应的算法可以产生更优的测试用例集,能更方便地完成软件的连续动态测试。     

逻辑语言剪枝算子的过程语义及其实现

论述了逻辑程序设计中剪枝算子的作用及传统剪枝算子的过程性语义和说明性语义不一致问题;介绍了新型逻辑程序语言〔淑划中的COTRTT11t剪枝算子;通过引入一组定义描述其过程语义,并进一步阐述了剪枝算子和延迟计算规则之间的关系,讨论了Godel语言的剪枝策略及控制机制,从而为逻辑程序语言的实现提供了依据。     

H∞-control and filtering with initial uncertainty for time-varying systems

The H∞-control problem with a non-zero initial condition is considered. The initial conditions are assumed to be in some subspace. First, the H∞-problem with full information is considered, and necessary and sufficient conditions for the norm of an input-output operator to be less than a given number are obtained. A characterization of all admissible controllers is given. This result is then used to solve the general H∞-control problem and the filtering problem with initial uncertainty. The filtering problem on a finite horizon involves an estimate of the state at the final time. The set of al1 suboptimal filters is given both on finite and infinite horizons.     

一种求解同等并行机调度的混合量子衍生进化规划算法

针对带顺序相关建立时间的同等并行机调度问题的求解,提出一种新的混合量子衍生进化规划算法.该算法通过定义新的量子个体来表示调度问题中的工件排序,并定义了针对调度问题的量子旋转角,使个体向更好的解靠近.同时,针对并行机问题本身,改进了个体的编码方式和新的变异方法.为了验证算法的有效性和收敛性,采用不同规模的算例进行仿真实验.结果表明,即使在小种群情况下,算法所得解均优于基本进化规划求得的解.     

Constructing triangular patch by basic approximation operator plus additional interpolation operator

~~Constructing triangular patch by basic approximation operator plus additional interpolation operator1. Barahill, R. E., Birkhoff, G., Gordon, W. J., Smooth interpolation in triangles, J. Approx. Theory, 1973, 8: 114-128. 2. Gregory, J. A., Smooth interpolation without twist constraints, in Computer Aided Geometric Design (eds. Barn-hill, R. E., Riesenfeld, R. R), New York: Academic Press, 1974, 71-88. 3. Charrot, P., Gregory, J. A., A pentagonal surface patch for comput…     

Characterizations and effective computation of supremal relatively observable sublanguages

Recently we proposed relative observability for supervisory control of discrete-event systems under partial observation. Relative observability is closed under set unions and hence there exists the supremal relatively observable sublanguage of a given language. In this paper we present a new characterization of relative observability, based on which an operator on languages is proposed whose largest fixpoint is the supremal relatively observable sublanguage. Iteratively applying this operator yields a monotone sequence of languages; exploiting the linguistic concept of support based on Nerode equivalence, we prove for regular languages that the sequence converges finitely to the supremal relatively observable sublanguage, and the operator is effectively computable. Moreover, for the purpose of control, we propose a second operator that in the regular case computes the supremal relatively observable and controllable sublanguage.     

Spectral characteristics and eigenvalues computation of the harmonic state operators in continuous-time periodic systems

Spectral characteristics of what we call the harmonic state operators in finite-dimensional linear continuous-time periodic (FDLCP) systems are examined by means of the Fredholm theory for the first time. It is shown that the harmonic state operator is a closed, densely defined Fredholm operator on the Hilbert space l₂, and its spectrum contains only eigenvalues of finite type in any bounded neighborhood of the origin of the complex plane. These spectral characteristics lead us to an asymptotic computation algorithm for the eigenvalues of the harmonic state operator via truncations on its Fredholm regularization. Furthermore, the truncation approach also gives us a necessary and sufficient stability criterion in the FDLCP setting, which only involves the Fourier coefficients of the state matrix. Asymptotic stability of the lossy Mathieu differential equation is investigated to illustrate the results.     

Causal invertibility

It is well known that in a given resolution space structure the inverse of a memoryless operator, when it exists, is also memoryless. Given a Hilbert resolution space, we define new resolution structures which preserve causality. We show that every causal, causally invertible operator can be viewed as a memoryless operator between resolution spaces. The characterization is both necessary and sufficient. We also identify causal operators which can be considered as memoryless in a suitable resolution space.     

Filtering for a class of discrete-time systems with time-delays via delta operator approach

In this article, a robust H _∞ filtering problem for a class of norm-bounded uncertain discrete-time systems with time delays is investigated using delta operator approach. Based on Lyapunov–Krasovskii functional in delta domain, a new delay-dependent sufficient condition for the solvability of this problem is presented in terms of linear matrix inequalities (LMIs). When these LMIs are feasible, an expression of a desired delta operator H _∞ filter is given. The proposed method can unify some previous related continuous and discrete systems into a delta operator systems framework. A numerical example is given to illustrate the effectiveness of the developed techniques.     

一种实数编码量子进化算法及其收敛性

基于量子计算理论和进化理论,提出一种新的量子进化算法--基于实数编码的量子进化算法(RQEA).不同于传统进化算法的单点编码和量子进化算法的量子比特编码,该算法以实数矩形区域表示基因,一条染色体携带多个个体信息,利用量子态叠加和相干机理,通过叠加、变异及自学习来完成进化过程,理论分析证明了算法具有全局收敛性,实验结果表明,该算法在函数优化上具有优异的性能.     

A combinatorial characterization of treelike resolution space

We show that the Player-Adversary game of Pudlák and Impagliazzo [A lower bound for DLL algorithms for k-SAT, in: Proc. 11th Annual ACM-SIAM Symposium on Discrete Algorithms, 2000, pp. 128-136] played over CNF propositional formulas gives an exact characterization of the space needed in treelike resolution refutations. This characterization is purely combinatorial and independent of the notion of resolution. We use this characterization to give for the first time a separation between the space needed in treelike and general resolution.     

INGIOWGA算子的多属性决策方法及其应用

研究了方案的属性评估信息以模糊语言形式给出的多属性群决策问题，在导出的有序加权几何平均（IOWGA）算子理论的基础上，给出了一种区间数广义导出有序加权几何平均（INGIOWGA）算子，利用广义的导出有序加权平均（GIOWA）算子，对专家所给出的对应于各方案的属性评估信息进行了集结，并提出了一种基于模糊语言评估和GIOWA算子的多属性群决策方法。利用该算法对X射线实时成像检测系统方案选择中的判断信息进行集结，并且通过算例说明了该方法的有效性和实用性。     

Changes of disjunctively closed bases

An operator of contraction for a belief set (a theory) can be obtained by assigning to it a belief base and an operator of partial meet contraction for that base. It is argued that closure of the base under disjunction is an intuitively reasonable condition. Axiomatic characterizations are given of the contractions of belief sets that can be generated by (various types of) partial meet contraction on disjunctively closed bases. The corresponding revision operators are also characterized. Finally, some results are reported on operations on bases that are closed under material implication.I would like to thank Hans Rott and two anonymous referees for valuable comments and the Swedish Council for Research in the Humanities and Social Sciences for financial support.     

灰色预测中缓冲算子的组合性质及应用

通过研究同性缓冲算子作用样本数据序列所得灰色预测模型的预测精度问题, 发现同类缓冲算子对于相同样本数据序列的预测值一致, 对于具体预测问题, 某个缓冲算子在此类问题中有效, 用到另一类问题上可能失效. 为此, 提出一种同性缓冲算子的组合方法, 通过对同性缓冲算子的有效组合可以得到一种新的缓冲算子, 该缓冲算子不但能够提高模型的预测精度, 而且可以扩大缓冲算子的适用范围. 实例验证表明, 所提出的组合方法是有价值的.