改进型高鲁棒性校正器的研究

鲁棒性是校正器设计的一个重要指标,本文在最优滤波器,状态反馈控制与合理的相角裕量的基础上,提出一种改进型的高鲁棒性校正器,这种方法可应用于有不确定性因素或变参数场合下的控制系统设计,以保证生产过程的安全,本改进型校正器的优良特性由仿真实验加以证实。     

Improvement of inductive power collection in null-flux maglev system

In the superconducting maglev system it is important to develop a non-contact on-board power source without environmental pollution such as noise and exhaust gases; therefore, inductive power collection (IPC), which utilizes a harmonic magnetic field generated by ground coils in EDS, is being studied. However, alteration to a null-flux EDS that has a high drag ratio reduces the power collecting capacity in the IPC system. In addition, power collecting coils are located on the cryostat of the superconducting coil (SC), so eddy currents at the cryostat also reduce the power collecting capacity. Therefore, an exclusive SC type that locates the exclusive SCs and IPC and power collecting coils so as to face the upper and lower coils of ground coils, respectively, is examined; but we aim to improve the conventional type. After analyzing the influence of eddy currents at the cryostat in detail and improving the composition of the power collecting coil and cryostat, we found that the conventional type has the same capacity as the exclusive SC type. In order to prove the above-mentioned result, we measured the induced voltage of the new-type coils in a test run at Miyazaki test track and confirmed the output of this IPC system in a full-scale synthetic bench test with a PWM converter and magnetic field simulator. © 1998 Scripta Technica. Electr Eng Jpn, 122(2): 48–60, 1998     

复杂网络零模型的量化评估

针对随机置乱算法生成复杂网络的零模型时,因不同阶次零模型成功置乱概率的差异导致难以准确判断零模型何时能够趋于稳定的问题,定义了"成功置乱次数"的概念,并提出使用"成功置乱次数"替代传统的"尝试置乱次数"进行算法设定。提出的成功置乱次数指标仅在随机选择的边满足相应阶次零模型的置乱条件从而被成功置乱后进行累加。各阶次零模型生成实验表明,使用该算法设定方式后各网络拓扑指标均能在较小的成功置乱次数范围内趋于稳定。进一步的量化分析表明,按阶次分别设定成功置乱次数为网络边数的2倍、1倍、1倍即可得到质量较好的0阶、1阶、2阶零模型。     

Killeen's (2005) prep coefficient: Logical and mathematical problems.

In his article, “An alternative to null-hypothesis significance tests,” Killeen (2005) urged the discipline to abandon the practice of pobs-based null hypothesis testing and to quantify the signal-to-noise characteristics of experimental outcomes with replication probabilities. He described the coefficient that he invented, prep, as the probability of obtaining “an effect of the same sign as that found in an original experiment” (Killeen, 2005, p. 346). The journal Psychological Science quickly came to encourage researchers to employ prep, rather than pobs, in the reporting of their experimental findings. In the current article, we (a) establish that Killeen's derivation of prep contains an error, the result of which is that prep is not, in fact, the probability that Killeen set out to derive; (b) establish that prep is not a replication probability of any kind but, rather, is a quasi-power coefficient; and (c) suggest that Killeen has mischaracterized both the relationship between replication probabilities and statistical inference, and the kinds of claims that are licensed by knowledge of the value assumed by the replication probability that he attempted to derive. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

稳定化的有限频段H∞控制及有限频段跟踪问题

基于GKYP引理的动态输出反馈设计,未保证设计后闭环系统的稳定性。针对以小增益作为指标的有限频段动态输出反馈问题,在不增加新变量的前提下,增加稳定性约束,使得设计后的闭环系统渐近稳定且满足有限频段性能指标。针对增加约束后难以找到可行解的情况,基于零空间条件的不惟一性,补充了另一种零空间条件,从而扩大了问题的可行域。将改进后的方法应用于有限频段跟踪问题的研究,通过仿真例子验证,有限频段动态输出反馈虽然存在保守性,但在合理选择基矩阵R的情况下,仍然可以使得其保守性小于传统的全频段最优H∞控制的保守性。     

掺铝校正料制备高硅尾矿基地聚合物

将某低活性高硅尾矿经活化预处理后,分别掺入铝酸钠(SA)、偏高岭土(MK)、粉煤灰(FA)和铝酸盐水泥(AC)作为铝校正料,在碱激发剂作用下制备地聚合物;以试样的7d抗压强度为考察指标,通过正交实验对各种铝校正料对应的反应体系的原料配比进行优化;为进一步提升试样的强度性能,将在优选配比下所制备的试样进行蒸压养护;通过SEM和27Al MAS-NMR对试样的微观形貌和所含Al的空间配位状态进行表征.结果表明:未做蒸压养护时,掺MK作铝校正料所制备的优选试样的7d抗压强度最高(即为27.5 MPa),掺不同铝校正料所得优选试样对应的最佳因素水平组合各不相同,各因素对G-SA、G-MK、G-FA和G-AC体系中试样抗压强度指标的影响规律多数不一致;试样经蒸压养护后,其强度性能和微结构均有改善,且掺SA对应的优选试样的强度增长率最高;掺不同铝校正料形成的试样在微观形貌上存在差异,但都形成了稳定的具有地聚合物基本特征的三维空间网络结构.     

基于属性可靠分析的空指针引用缺陷检测

为实现基于静态分析技术充分地检测出C程序中的空指针引用缺陷,提出了一种基于属性可靠分析的缺陷检测方法。首先介绍了空指针引用缺陷模式及特征。然后针对空指针引用缺陷的检测特点提出了属性可靠分析理论,并将指针的指向属性描述为一个属性格。通过提出的抽象内存模型,基于给出的每种程序语句上的迁移实现指针指向属性的可靠分析,根据得到的每个被引用指针的指向属性进而实现空指针引用缺陷的检测。通过对五个实际工程的检测结果分析表明,方法可充分检测出C程序的空指针引用缺陷。     

An improved numerical scheme for the sine‐Gordon equation in 2+1 dimensions

A rational approximant of order 4, which is applied to a three‐time‐level recurrence relation, is used to transform the initial/boundary‐value problem associated with the two‐dimensional sine‐Gordon (SG) equation arising in the Josephson junctions problem. The resulting non‐linear system, which is analyzed for stability, is solved using an appropriate predictor–corrector (P–C) scheme, in which an explicit scheme of order 2 is used as predictor. For the implementation of the corrector, in order to avoid extended matrix evaluations, an auxiliary vector was successfully introduced. In this P–C scheme, a modification in the corrector has been proposed according to which the already evaluated corrected values are considered. The behavior of this P–C scheme is tested numerically on line and ring solitons known from the bibliography regarding the SG equation and conclusions for both undamped and damped problems are derived. Copyright © 2008 John Wiley & Sons, Ltd.     

液晶波前校正器动态位相响应特性研究

为了对畸变波前进行精确校正,研究了液晶波前校正器在不同灰度级之间的动态位相响应特性,准确确定其响应时间。首先给出液晶波前校正器的响应时间和位相变化的检测方案。然后检测了液晶波前校正器在0和255灰度级之间的上升和下降时间,分别为7ms和11ms。在保证校正精度的条件下,对该位相曲线采取λ/10的误差截断,使上升和下降时间分别减少到4ms和6.8ms。最后,研究了各灰度级依次上升到255和从255再以次回落到各灰度级的动态响应时间。结果表明,各灰度级的上升时间在2～5.2ms之间变化,下降时间在3.66～8.74ms之间变化,且无论是上升还是下降,150和255灰度级之间转换速度最快,在255灰度级邻近的灰度响应速度最慢,且响应时间长于0和255灰度之间的响应时间。因此,在波前校正中,须以255灰度邻近的灰度级中最长的响应时间作为液晶波前校正器的响应时间,以确保波前校正精度。