Tuples of Disjoint $\mathsf{NP}$ -Sets

Disjoint -pairs are a well studied complexity-theoretic concept with important applications in cryptography and propositional proof complexity. In this paper we introduce a natural generalization of the notion of disjoint -pairs to disjoint k-tuples of -sets for k≥2. We define subclasses of the class of all disjoint k-tuples of -sets. These subclasses are associated with a propositional proof system and possess complete tuples which are defined from the proof system. In our main result we show that complete disjoint -pairs exist if and only if complete disjoint k-tuples of -sets exist for all k≥2. Further, this is equivalent to the existence of a propositional proof system in which the disjointness of all k-tuples is shortly provable. We also show that a strengthening of this conditions characterizes the existence of optimal proof systems. An extended abstract of this paper appeared in the proceedings of the conference CSR 2006 (Lecture Notes in Computer Science 3967, 80–91, 2006). Supported by DFG grant KO 1053/5-1.     

On the combination of ${\it abstract-level}$ classifiers

This paper presents a framework for the analysis of similarity among abstract-level classifiers and proposes a methodology for the evaluation of combination methods. In this paper, each abstract-level classifier is considered as a random variable, and sets of classifiers with different degrees of similarity are systematically simulated, combined, and studied. It is shown to what extent the performance of each combination method depends on the degree of similarity among classifiers and the conditions under which each combination method outperforms the others. Experimental tests have been carried out on simulated and real data sets. The results confirm the validity of the proposed methodology for the analysis of combination methods and its usefulness for multiclassifier system design.Received: 6 September 2002, Published online: 6 June 2003     

基于非二次Lyapunov函数的不确定模糊系统鲁棒${H_infty }$控制

研究一类具有参数不确定的T-S模糊系统鲁棒镇定和鲁棒${H_\infty     

Simulating a $2M commercial server on a $2K PC

As dependence on database management systems and Web servers increases, so does the need for them to run reliably and efficiently-goals that rigorous simulations can help achieve. Execution-driven simulation models system hardware. These simulations capture actual program behavior and detailed system interactions. The authors have developed a simulation methodology that uses multiple simulations, pays careful attention to the effects of scaling on workload behavior, and extends Virtutech AB's Simics full system functional simulator with detailed timing models. The Wisconsin Commercial Workload Suite contains scaled and tuned benchmarks for multiprocessor servers, enabling full-system simulations to run on the PCs that are routinely available to researchers.     

基于自适应事件触发的时滞系统分布式${l_2}text{-}{l_infty}$滤波

研究一类基于自适应事件触发机制的时滞系统分布式滤波问题.自适应事件触发条件由滤波器自身最新释放数据、当前时刻估计值及邻居节点最新释放数据共同决定.此事件触发机制采用阈值自适应调节方案,阈值参数在保证滤波器性能的前提下根据滤波误差动态变化,最大程度上节约网络通信资源.首先,给出滤波误差系统均方指数稳定的充分条件;其次,构造一个Lyapunov函数来分析滤波误差系统满足l2-l∞的性能指标;再次,设计离散时滞系统分布式l₂-l_∞滤波器,并通过线性矩阵不等式方法求解滤波器参数;最后,通过仿真实例说明滤波器能够降低系统时滞带来的影响,且在保证滤波性能前提下减少通信次数,节约网络资源.     

The $100 role model

Louise Brown of Clove Business Systems looks at the work ofa worthy female role model, Mary Lou Jepsen.     

A robust nonsmooth generalized-α$\alpha $ scheme for flexible systems with impacts

Multibody System Dynamics - The aim of this work is the development of a robust and accurate time integrator for the simulation of the dynamics of multibody systems composed of rigid and/or...     

On P versus NP $ \cap $ co-NP for decision trees and read-once branching programs

It is known that if a Boolean function f in n variables has a DNF and a CNF of size then f also has a (deterministic) decision tree of size exp(O(log n log² N)). We show that this simulation cannot be made polynomial: we exhibit explicit Boolean functions f that require deterministic trees of size exp where N is the total number of monomials in minimal DNFs for f and ?f. Moreover, we exhibit new examples of explicit Boolean functions that require deterministic read-once branching programs of exponential size whereas both the functions and their negations have small nondeterministic read-once branching programs. One example results from the Bruen—Blokhuis bound on the size of nontrivial blocking sets in projective planes: it is remarkably simple and combinatorially clear. Other examples have the additional property that f is in AC⁰. Received: June 5 1997.     

S120伺服驱动器的使用

介绍S120做基本定位控制时,采用不同的回零方式对状态字的影响,修改电机与编码器正方向及故障复位后硬件开关对S120伺服的影响。     

基于\begin{document}$ \pmb k $\end{document}近邻主元得分差分的故障检测策略

针对具有非线性和多模态特征过程的故障检测问题, 本文提出一种基于k近邻主元得分差分的故障检测策略.首先, 通过主元分析(Principal component analysis, PCA)方法计算样本的真实得分.然后, 应用样本的k近邻均值计算样本估计得分.接下来, 通过上述两种得分计算样本的得分差分矩阵和残差矩阵, 其中残差矩阵由样本的估计得分计算得到,这区别于传统方法.最后, 在差分子空间和残差子空间中分别建立新的统计指标进行故障检测.值得注意的是本文的得分差分方法能够消除数据结构对过程故障检测的影响, 同时, 新的统计量能够提高过程的故障检测率.将本文方法在两个模拟例子和Tennessee Eastman (TE)过程中进行测试, 并与传统方法如PCA、KPCA、DPCA和~FD-kNN等进行对比分析, 测试结果证明了本文方法的有效性.