526 research outputs found
m-step preconditioners for nonhermitian positive definite Toeplitz systems
It is known that if A is a Toeplitz matrix,then A enjoys a circulant and skew circulant splitting(de—
noted by CSCS),i.e.,A=C+ S with C a circulant matrix and S a skew circulant matrix. Based on the CSCS iteration,we give m-step preconditioners P for certain classes of Toeplitz matrices in this paper.We
show that if both C and S are positive definite,then the spectrum of the preconditioned matrix(PA)^* PA are
clustered around one for some moderate size . Experimental results show that the proposed preconditioners
perform slightly better than T.Chan’S preconditioners for some moderate size m.info:eu-repo/semantics/publishedVersio
14-Methoxy-2,16-dioxapentacyclo[7.7.5.01,21.03,8.010,15]henicosa-3(8),10,12,14-tetraene-7,20-dione
The title compound, C20H20O5, was synthesized from the reaction between 3-methoxysalicaldehyde and 1,3–cyclohexanedione in the presence of palladium(II) chloride. The two fused xanthene rings and one of the six-membered cyclohexane rings adopt envelope conformations, while the other six-membered cyclohexane ring is in a chair conformation. The molecular packing is stabilized by weak intermolecular C—H⋯O interactions
CTL Model Update for System Modifications
Model checking is a promising technology, which has been applied for
verification of many hardware and software systems. In this paper, we introduce
the concept of model update towards the development of an automatic system
modification tool that extends model checking functions. We define primitive
update operations on the models of Computation Tree Logic (CTL) and formalize
the principle of minimal change for CTL model update. These primitive update
operations, together with the underlying minimal change principle, serve as the
foundation for CTL model update. Essential semantic and computational
characterizations are provided for our CTL model update approach. We then
describe a formal algorithm that implements this approach. We also illustrate
two case studies of CTL model updates for the well-known microwave oven example
and the Andrew File System 1, from which we further propose a method to
optimize the update results in complex system modifications
9-(4-Chlorophenyl)-4a-hydroxy-4,4a,5,6,9,9a-hexahydro-3H-xanthene-1,8(2H,7H)-dione
In the title compound, C19H19ClO4, the central fused ring and the attached cyclohexene ring adopt envelope conformations, while the cyclohexane ring adopts a chair conformation. The crystal packing is stabilized by O—H⋯O hydrogen bonds, which link the molecules into a chain along the b axis. Weak C—H⋯O bonds also occur
Studies on Left‐Behind Children in China: Reviewing Paradigm Shifts
More than 60 million children have been left behind in rural China by parents going to work in cities. Given the effects of child–parent separation (CPS) on development, this phenomenon has drawn considerable governmental and academic attention in recent years. Outlining developments with reference to relevant studies, this review characterizes the perspectives used to explore and understand this phenomenon in terms of three major paradigms: (1) the diagnostic approach, which takes for granted the assumption that CPS would be the only cause of negative effects observed among left‐behind children (LBC), and has focused primarily on measuring psychological and behavioral disorders among these “problematic kids”; (2) the advanced diagnostic approach, which refines the previous approach by incorporating theories and techniques developed outside of China, elaborating on the early approach by bringing into consideration more factors and exploring the interactions between CPS and these factors, particularly social ones; (3) the sociologically oriented approach, which provides the research with a much broader framework in terms of how to orient the phenomenon of LBC, especially the transformation of China’s social and economic systems during the last 30 years of urbanization, where the reproduction of labor has been based on a “splitting family structure,” such that problems associated with the phenomenon of LBC cannot be solved without systematic social and economic changes. Based on these analyses, future directions for research on LBC in China are also discussed.Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/147833/1/cad20267_am.pdfhttps://deepblue.lib.umich.edu/bitstream/2027.42/147833/2/cad20267.pd
The effect of pressure-sensitive adhesive properties on screenability
"July 2002."Submitted to 2nd International Symposium on Emerging Technologies of Pulping and Papermaking of Fast Growing Wood, October 9-11, 2002, Guangzhou, China
Frontal EEG Asymmetry and Middle Line Power Difference in Discrete Emotions
A traditional model of emotion cannot explain the differences in brain activities between two discrete emotions that are similar in the valence-arousal coordinate space. The current study elicited two positive emotions (amusement and tenderness) and two negative emotions (anger and fear) that are similar in both valence and arousal dimensions to examine the differences in brain activities in these emotional states. Frontal electroencephalographic (EEG) asymmetry and midline power in three bands (theta, alpha and beta) were measured when participants watched affective film excerpts. Significant differences were detected between tenderness and amusement on FP1/FP2 theta asymmetry, F3/F4 theta and alpha asymmetry. Significant differences between anger and fear on FP1/FP2 theta asymmetry and F3/F4 alpha asymmetry were also observed. For midline power, midline theta power could distinguish two negative emotions, while midline alpha and beta power could effectively differentiate two positive emotions. Liking and dominance were also related to EEG features. Stepwise multiple linear regression results revealed that frontal alpha and theta asymmetry could predict the subjective feelings of two positive and two negative emotions in different patterns. The binary classification accuracy, which used EEG frontal asymmetry and midline power as features and support vector machine (SVM) as classifiers, was as high as 64.52% for tenderness and amusement and 78.79% for anger and fear. The classification accuracy was improved after adding these features to other features extracted across the scalp. These findings indicate that frontal EEG asymmetry and midline power might have the potential to recognize discrete emotions that are similar in the valence-arousal coordinate space
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