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2.
In this paper, permanent magnet synchronous motors (PMSMs) are investigated. According to the feature of PMSMs, a novel state equation of PMSMs is obtained by choosing suitable state variables. Based on the state equation, robust controllers are designed via interval matrix and PI control idea. In terms of bilinear matrix inequations, sufficient conditions for the existence of the robust controller are derived. In order to reduce the conservation and the dependence on parameter, the control inputs of PMSMs are divided into two parts, a feedforward control input and a feedback control input, and relevant sufficient conditions for the existence of the controller are obtained. Because of the suitable choice of state variables, the proposed control strategies can cope with the load uncertainty and have robustness for disturbance. Finally, simulations are carried out via Matlab/Simulink soft to verify the effectiveness of the proposed control strategies. The performance of the proposed control strategies are demonstrated by the simulation results. 相似文献
3.
Thioux Marc; Stark David E.; Klaiman Cheryl; Schultz Robert T. 《Canadian Metallurgical Quarterly》2006,32(5):1155
Some individuals are able to determine the weekday of a given date in a few seconds (finding for instance that June 12, 1900, was a Tuesday). This ability has fascinated scientists for many years because it is predominantly observed in people with limited intelligence and may appear very early in life. Exceptional visual memory, exceptional concentration abilities, or privileged access to lower levels of information not normally available through introspection have been advanced to explain such phenomena. In the present article, the authors show that a simple cognitive model can explain all aspects of the performance of Donny, a young autistic savant who is possibly the fastest and most accurate calendar prodigy ever described. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
4.
The applicability of the identical elements (IE) model of arithmetic fact retrieval (T. C. Rickard, A. F. Healy, & L. E. Bourne, 1994) to cued recall from episodic (image and sentence) memory was explored in 3 transfer experiments. In agreement with results from arithmetic, speedup following even minimal practice recalling a missing word from an episodically bound word triplet did not transfer positively to other cued recall items involving the same triplet. The shape of the learning curve further supported a shift from episode-based to IE-based recall, extending some models of skill learning to cued recall practice. In contrast with previous findings, these results indicate that a form of representation that is independent of the original episodic memory underlies cued-recall performance following minimal practice. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
5.
结合松辽盆地大庆长垣西侧扶余、杨大城子油层的勘探实践,从顶生下储的特殊成藏原理出发,详细地讨论了扶余、杨大城子油层的油水层形成机理,提出了2种形成模式。认为扶杨油层的油水同层是在以上覆烃源岩的超压为驱动力的成藏条件下形成,油水混合运移注入储层,由于储层的孔喉小,油水重力分异不好,造成孔隙存油,喉道存水。这种低渗透储层孔隙结构复杂,含油饱和度低,油水在孔隙中分布状况特殊,使得电阻率等曲线反映流体的信息变弱,造成油水层识别变难。为此提出多参数降维油气水层识别方法,经实际应用取得较好的效果。 相似文献
6.
中原油田岩石可钻性与声波时差关系研究 总被引:3,自引:0,他引:3
选取中原油田的大量岩心,采用常规岩石力学测试方法测定了岩石的可钻性、声波测试方法测定了岩石和岩屑声波时差,通过对测得的岩石可钻性级值和声波时差进行回归拟合,得出了中原油田岩石可钻性与声波时差的关系式。现场应用表明,该关系式较好地反映了中原油田地层岩石可钻性与声波时差的关系,可以在优选钻头时作为参考或直接应用。 相似文献
7.
Javier Ramírez Antonio García Uwe Meyer-Bäse Fred Taylor Antonio Lloris 《The Journal of VLSI Signal Processing》2003,33(1-2):171-190
Currently there are design barriers inhibiting the implementation of high-precision digital signal processing (DSP) objects with field programmable logic (FPL) devices. This paper explores overcoming these barriers by fusing together the popular distributed arithmetic (DA) method with the residue number system (RNS) for use in FPL-centric designs. The new design paradigm is studied in the context of a high-performance filter bank and a discrete wavelet transform (DWT). The proposed design paradigm is facilitated by a new RNS accumulator structure based on a carry save adder (CSA). The reported methodology also introduces a polyphase filter structure that results in a reduced look-up table (LUT) budget. The 2C-DA and RNS-DA are compared, in the context of a FPL implementation strategy, using a discrete wavelet transform (DWT) filter bank as a common design theme. The results show that the RNS-DA, compared to a traditional 2C-DA design, enjoys a performance advantage that increases with precision (wordlength). 相似文献
8.
火焰图像特征在火灾数字图像识别中的运用 总被引:1,自引:0,他引:1
火焰尖角数目和圆形度是早期火灾火焰的主要特征,本文主要论述了如何在数学形态学基础上,利用火灾火焰的两个特点判断和识别早期火情。实验中,对火焰的二值图像进行开运算,即先腐蚀,再膨胀,目的是为了对火焰图像进行形态学滤波,去噪。从实验结果可以看出,该算法可以很好的识别火焰和干扰源。 相似文献
9.
Four experiments investigated the effect of recent selective practice on the cost of switching between 2 tasks afforded by letter-digit pairs: alphabet arithmetic and shape comparison. Experiments 1 and 2 found a greater cost associated with switching to the more recently practiced task: evidence that task-set inertia contributes to switching costs. Experiment 3 found this effect to be limited to trials on which a recently trained stimulus followed another such stimulus: a result problematic for all current theories of task-set priming. Experiment 4 showed that the effect of recent practice was eliminated by active preparation for a task switch: It appears that endogenous task-set preparation reduces the effects of task-set inertia. (PsycINFO Database Record (c) 2010 APA, all rights reserved) 相似文献
10.
The Clopper-Pearson confidence interval has ever been documented as an exact approach in some statistics literature. More recently, such approach of interval estimation has been introduced to probabilistic control theory and has been referred as non-conservative in control community. In this note, we clarify the fact that the so-called exact approach is actually conservative. In particular, we derive analytic results demonstrating the extent of conservatism in the context of probabilistic robustness analysis. This investigation encourages seeking better methods of confidence interval construction for robust control purpose. 相似文献