An LMI approach to synthesis subject to almost asymptotic regulation constraints

A multi-objective controller synthesis problem is considered in which an output is to be regulated approximately by assuring a bound on the steady-state peak amplification in response to an infinite-energy disturbance, while also guaranteeing a desired level of performance measured in terms of the worst-case energy gain from a finite-energy input to a performance output. Relying on a characterization of the controllers with which almost asymptotic regulation is accomplished, the problem of guaranteeing the desired level of performance is reduced to solving a system of linear matrix inequalities subject to a set of linear equality constraints. Based on the solution of this system, a procedure is outlined for the construction of a suitable controller whose order is equal to the order of the plant plus the order of the exogenous system.     

Circuits constructed with MOD q gates cannot compute “AND” in sublinear size

Algebraic techniques are used to prove that any circuit constructed with MOD _q gates that computes the AND function must use (n) gates at the first level. The best bound previously known to be valid for arbitraryq was (logn).     

Robust model selection with flexible trimming

The forward search provides data-driven flexible trimming of a C_p statistic for the choice of regression models that reveals the effect of outliers on model selection. An informed robust model choice follows. Even in small samples, the statistic has a null distribution indistinguishable from an F distribution. Limits on acceptable values of the C_p statistic follow. Two examples of widely differing size are discussed. A powerful graphical tool is the generalized candlestick plot, which summarizes the information on all forward searches and on the choice of models. A comparison is made with the use of M-estimation in robust model choice.     

Solving Third Order Differential Equations with Maximal Symmetry Group

The largest group of Lie symmetries that a third-order ordinary differential equation (ode) may allow has seven parameters. Equations sharing this property belong to a single equivalence class with a canonical representative v ^′′′(u)=0. Due to this simple canonical form, any equation belonging to this equivalence class may be identified in terms of certain constraints for its coefficients. Furthermore a set of equations for the transformation functions to canonical form may be set up for which large classes of solutions may be determined algorithmically. Based on these steps a solution algorithm is described for any equation with this symmetry type which resembles a similar scheme for second order equations with projective symmetry group. Received March 9, 2000; revised June 8, 2000     

基于TPS40平台的降压型DC-DC电源设计和测试

本文在TPS40平台上设计降压式DC-DC直流电源电路,对电路进行了验证测试。设计中电路选用了TPS40007为控制芯片,给出了设计电路原理图,并进行了电路相关数据分析,电源转换效率分析和幅频特性分析。     

Comparison of the Hansen-Sengupta and the Frommer-Lang-Schnurr existence tests

The Krawczyk and the Hansen-Sengupta interval operators are closely related to the interval Newton operator. These interval operators can be used as existence tests to prove existence of solutions for systems of equations. It is well known that the Krawczyk operator existence test is less powerful that the Hansen-Sengupta operator existence test, the latter being less powerful than the interval Newton operator existence test. In 2004, Frommer et al. proposed an existence test based on the Poincaré-Miranda theorem and proved that it is more powerful than the Krawczyk existence test. In this paper, we complete the classification of these four existence tests showing that, in practice, the Hansen-Sengupta existence test is actually more powerful than the existence test proposed by Frommer et al.     

A crucial experiment resubmitted.

Presents the "experiment" conducted by the prophet Elijah in 1 Kings 18:17–40 in which the priests of Baal and Elijah each sacrificed a bull and invoked the name of their respective god, but only Elijah's god responded. Satirical comments of 3 "reviewers" of psychological articles are included to show the ethical and methodological issues that might be raised if such an experiment were conducted today. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Towards optimal simulations of formulas by bounded-width programs

We show that, over an arbitrary ring, for any fixed >0, all balanced algebraic formulas of sizes are computed by algebraic straight-line programs that employ a constant number of registers and have lengthO (s ¹⁺). In particular, in the special case where the ring isGF(2), we obtain a technique for simulating balanced Boolean formulas of sizes by bounded-width branching programs of lengthO(s ¹⁺), for any fixed >0. This is an asymptotic improvement in efficiency over previous simulations in both the Boolean and algebraic settings.     

亚临界热处理对40SiMnCrNiMo高强度钎钢组织和性能的影响

为简化40SiMnCrNiMo钢钎具的热处理工艺，试验了880℃30min油冷＋600℃60min空冷的调质处理，860℃30min空冷的正火和780℃30min空冷的两相区亚临界热处理后钢的组织和性能。结果表明，亚临界热处理后钢中贝氏体区HV显微硬度值低于正火钢，钢的V-型冲击功为30J，高于正火后钢V-型冲击功（12J），接近调质后的V-型冲击功（40J）。钎杆寿命试验得出，正火钢钎具平均钻孔进尺10．78m，亚临界热处理钢钎具平均钻孔进尺108．30m，可满足使用要求和替代调质处理钎杆。     

HK40钢的渗铝新工艺及抗碳化腐蚀性能研究

采用金相显微镜(OM)、扫描电子显微镜(SEM)、X射线衍射仪(XRD)、X射线能谱分析仪(EDAX)等仪器设备研究了HK40钢的渗铝及其抗碳化腐蚀能力.试验结果表明,通过调整渗剂中特种添加剂与铝粉的比例和渗铝温度等工艺参数,可达到控制渗铝层相组成的目的.与传统一段法固体粉末渗铝工艺相比,两段法固体粉末渗铝工艺可提高渗速约60%.HK40钢的渗铝层由NiAl相和Ni3Al相组成时,其抗碳化腐蚀能力得到明显提高.