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61.
In this paper, we propose a design method of guaranteed cost controllers for uncertain large-scale systems with time delays in subsystem interconnections using delayed feedback. Using the Lyapunov method, a linear matrix inequality (LMI) optimization problem is formulated to design a delayed feedback controller which minimizes the upper bound of a given quadratic cost function. A numerical example is included to illustrate the design procedures.Communicated by Q. C. ZhaoThe authors thank the Associate Editor and three anonymous referees for careful reading and useful suggestions. 相似文献
62.
In this paper, blue thermally activated delayed fluorescence (TADF) organic light-emitting diodes (OLEDs) have been elucidated, with a focus on the degradation characteristics of the emission layer (EML). The operational stability against electrical stress was investigated for two host materials and four doping concentrations, which were used as the EML. The operating stability of the devices was confirmed by comparing the peak capacitance before and after degradation. Devices using bis [2-(diphenyl-phosphino) phenyl] ether oxide (DPEPO) as a host exhibited poor degradation characteristics. However, high stability was confirmed when 3,3-di (9H-carba-zol-9-yl)-biphenyl (mCBP) was used. DPEPO host devices are most resistant against performance degradation when they are doped with 10 wt% 10,10'-(4,4′-sulfonylbis(4,1-phenylene))bis(9,9-dimethyl-9,10-dihydroacridine (DMAC-DPS). We successfully determined the electroluminescence characteristics of the device depending on the host material, as well as the doping concentration, using the capacitance–voltage method. 相似文献
63.
Ziwen Jiang Yongsheng Zhao Zhixun Luo Aidong Peng Hao Wang Prof. Dr. Jiannian Yao 《中国化学》2010,28(11):2103-2108
Doped nanoparticles were prepared from pyrene and phenanthrene using a facile reprecipitation method. The doped nanoparticles presented unique delayed fluorescent emissions of pyrene under the unprotected condition. The ratio of the intensity of delayed fluorescence (IDF) to that of phosphorescence (IP) is about 4:1, which almost keeps unchanged with the decrease of pyrene content at room temperature. The intensity of the delayed fluorescence emissions is dependent on the relative content of pyrene, as well as the aggregation degree of nanoparticles. The delayed emissions are contributed to efficient triplet‐triplet energy transfer from phenanthrene (donor) to pyrene (acceptor). Steady fluorescence measurement have proved that the singlet‐singlet energy transfer process was also existent dominated by the radiation energy transfer mechanism. 相似文献
64.
We consider nonsynchronous sampling of parameterized stochastic regression models, which contain stochastic differential equations. Constructing a quasi-likelihood function, we prove that the quasi-maximum likelihood estimator and the Bayes type estimator are consistent and asymptotically mixed normal when the sampling frequency of the nonsynchronous data becomes large. 相似文献
65.
Robust decentralized adaptive synchronization of general complex networks with coupling delayed and uncertainties
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The problem of robust decentralized adaptive synchronization of general complex networks with coupling delayed and uncertainties is investigated in this article. It is only assumed that the upper normal bound of uncertain inner and outer coupling matrices is positive but its concrete structure is not also required to be known. The time‐varying coupling delay is a any nonnegative continuous and bounded function and not require its derivative to be less than one, that is, general time‐varying coupling delays and uncertainties. For such a class of uncertain complex networks, a new synchronization scheme is presented by a class of continuous memoryless robust decentralized adaptive synchronization controllers. It is also shown that the synchronization error dynamics of uncertain complex networks can be guaranteed as uniformly exponentially convergent toward a ball that can be as small as desired. Finally, numerical simulations are provided to demonstrate the effectiveness and robustness of proposed complex networks synchronization schemes. © 2013 Wiley Periodicals, Inc. Complexity 19: 10–26, 2014 相似文献
66.
像计算机、电视机、空调等这类具有物理变质的可能性很小,但生命周期较短、不断更新换代、价值不断贬值的电子产品会发生无形变质的现象.在假设无形变质率与需求率负相关,同时在产品的存储过程中,考虑库存水平对销售量的影响情况下,研究需求受库存水平影响、且缺货时存在延迟订货的短生命周期物品的库存管理问题.创新之处在于考虑了产品的缺货问题;在允许缺货的条件下,建立了短生命周期物品的库存模型;运用数值算例进行了求解和验证;并对各参数进行了敏感性分析. 相似文献
67.
G. Pizzella 《Il Nuovo Cimento C》1995,18(3):285-294
Summary A brief historical survey of the GW experiments is presented. In particular, the experiments with resonant detectors are illustrated
and the problems arising when comparing data of different detectors for the search of coincidences are discussed. The experimental
results so far obtained are shown, among them the correlation during the SN1987A with various GW and neutrino detectors. Finally
a warning for the long times needed to improve the sensitivity of the GW detectors is given and the improvements expected
with spherical resonant detectors are mentioned. 相似文献
68.
Dai Binxiang Zhang Na 《Annals of Differential Equations》2007,23(2):136-140
With the help of a continuation theorem based on Gaines and Mawhin's coincidence degree,some sufficient conditions are established for the global existence of positive periodic solutions of a class of delayed nonlinear difference equations. 相似文献
69.
We consider several applications of two state, finite action, infinite horizon, discrete-time Markov decision processes with partial observations, for two special cases of observation quality, and show that in each of these cases the optimal cost function is piecewise linear. This in turn allows us to obtain either explicit formulas or simplified algorithms to compute the optimal cost function and the associated optimal control policy. Several examples are presented.Research supported in part by the Air Force Office of Scientific Research under Grant AFOSR-86-0029, in part by the National Science Foundation under Grant ECS-8617860, in part by the Advanced Technology Program of the State of Texas, and in part by the DoD Joint Services Electronics Program through the Air Force Office of Scientific Research (AFSC) Contract F49620-86-C-0045. 相似文献
70.
本文通过对薄透镜距测量的改进,并以薄透镜焦距测量为例进行误差分析及讨论.恰当地运用数学工具对观测数据做出科学的分析处理,获得正确的结论,对提高实验能力和运用误差理论来处理实验数据起到很大作用. 相似文献