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Search Results: 1 - 10 of 76554 matches for " Ma Wei "
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Period-One Rotating Solutions of Horizontally Excited Pendulum Based on Iterative Harmonic Balance  [PDF]
Hui Zhang, Tian-Wei Ma
Advances in Pure Mathematics (APM) , 2015, DOI: 10.4236/apm.2015.58041
Abstract: In this study, the iterative harmonic balance method was used to develop analytical solutions of period-one rotations of a pendulum driven horizontally by harmonic excitations. The performance of the method was evaluated by two criteria, one based on the system energy error and the other based on the global residual error. As a comparison, analytical solutions based on the multi-scale method were also considered. Numerical solutions obtained from the Dormand-Prince method (ODE45 in MATLAB©) were used as the baseline for evaluation. It was found that under lower-level excitations, the multi-scale method performed better than the iterative method. At higher-level excitations, however, the performance of the iterative method was noticeably more accurate.
Interference-Free Wakeup Scheduling with Consecutive Constraints in Wireless Sensor Networks
Junchao Ma,Wei Lou
International Journal of Distributed Sensor Networks , 2012, DOI: 10.1155/2012/525909
Abstract: Wakeup scheduling has been widely used in wireless sensor networks (WSNs), for it can reduce the energy wastage caused by the idle listening state. In a traditional wakeup scheduling, sensor nodes start up numerous times in a period, thus consuming extra energy due to state transitions (e.g., from the sleep state to the active state). In this paper, we address a novel interference-free wakeup scheduling problem called compact wakeup scheduling, in which a node needs to wake up only once to communicate bidirectionally with all its neighbors. However, not all communication graphs have valid compact wakeup schedulings, and it is NP-complete to decide whether a valid compact wakeup scheduling exists for an arbitrary graph. In particular, tree and grid topologies, which are commonly used in WSNs, have valid compact wakeup schedulings. We propose polynomial-time algorithms using the optimum number of time slots in a period for trees and grid graphs. Simulations further validate our theoretical results.
Group theory analysis of braided geometry structures
Wei Feng,Wensuo Ma
Chinese Science Bulletin , 2005, DOI: 10.1007/BF03183644
Abstract: The braided geometry structures are analyzed with point groups and space groups for which the continuous yarn of the braided preforms is segmented and expressed in some special symbols. All structures of braided material are described and classified with group theory, and new braiding methods are found. The group theory analysis lays the theoretical foundation for optimizing material performance.
Boundary Galerkin Method of a Skew-Derivative Problem in the Exterior of an Open Arc Based on Chebyshev Polynomials
Wei Sun,Fuming Ma
Mathematical Problems in Engineering , 2013, DOI: 10.1155/2013/354267
Abstract:
The Great Gatsby: A Contrastive Study of Its Two Chinese Versions
Jinxing Ma,Ning Wei
Asian Social Science , 2009, DOI: 10.5539/ass.v4n8p32
Abstract: This paper, based on theories of Contrastive Linguistics deals with the contrastive study concerning two Chinese versions of the Great Gatsby rendered respectively by Wu Ran, and Wu Ningkun et al from the following two perspectives: differences on lexicon and syntax. Through a systematic comparison and contrast, the writer suggests that we should apply contrastive studies of English and Chinese in our TEFL practice to enhance teaching efficiency.
Properties of positive solutions of an Elliptic Equation with negative exponents
Li Ma,Juncheng Wei
Mathematics , 2007,
Abstract: In this paper, we study the existence and non-existence result of positive solutions to a singular elliptic equation with negative power on the bounded smooth domain or in the whole Euclidean space. Our model arises in the study of the steady states of thin films and other applied physics. We can get some useful local gradient estimate and L1 lower bound for positive solutions of the elliptic equation. A uniform positive lower bound for convex positive solutions is also obtained. We show that in lower dimensions, there is no stable positive solutions in the whole space. In the whole space of dimension two, we can show that there is no positive smooth solution with finite Morse index. Symmetry properties of related integral equations are also given.
On the generalized Feynman-Kac transformation for nearly symmetric Markov processes
Li Ma,Wei Sun
Mathematics , 2010,
Abstract: Suppose $X$ is a right process which is associated with a non-symmetric Dirichlet form $(\mathcal{E},D(\mathcal{E}))$ on $L^{2}(E;m)$. For $u\in D(\mathcal{E})$, we have Fukushima's decomposition: $\tilde{u}(X_{t})-\tilde{u}(X_{0})=M^{u}_{t}+N^{u}_{t}$. In this paper, we investigate the strong continuity of the generalized Feynman-Kac semigroup defined by $P^{u}_{t}f(x)=E_{x}[e^{N^{u}_{t}}f(X_{t})]$. Let $Q^{u}(f,g)=\mathcal{E}(f,g)+\mathcal{E}(u,fg)$ for $f,g\in D(\mathcal{E})_{b}$. Denote by $J_1$ the dissymmetric part of the jumping measure $J$ of $(\mathcal{E},D(\mathcal{E}))$. Under the assumption that $J_1$ is finite, we show that $(Q^{u},D(\mathcal{E})_{b})$ is lower semi-bounded if and only if there exists a constant $\alpha_0\ge 0$ such that $\|P^{u}_{t}\|_2\leq e^{\alpha_0 t}$ for every $t>0$. If one of these conditions holds, then $(P^{u}_{t})_{t\geq0}$ is strongly continuous on $L^{2}(E;m)$. If $X$ is equipped with a differential structure, then this result also holds without assuming that $J_1$ is finite.
Easily Implemented Rate Compatible Reconciliation Protocol for Quantum Key Distribution
Zhengchao Wei,Zhi Ma
Computer Science , 2013,
Abstract: Reconciliation is an important step to correct errors in Quantum Key Distribution (QKD). In QKD, after comparing basis, two legitimate parties possess two correlative keys which have some differences and they could obtain identical keys through reconciliation. In this paper, we present a new rate compatible reconciliation scheme based on Row Combining with Edge Variation (RCEV) Low Density Parity Check (LDPC) codes which could change code rate adaptively in noisy channel where error rate may change with time. Our scheme is easy to implement and could get good efficiency compared to existing schemes. Meanwhile, due to the inherent structure we use, the new scheme not only saves memory space remarkably but also simplifies the decoder architecture and accelerates the decoding.
BF3.OEt2-Mediated Benzylation of Arenes and Heteroarenes with Benzyl Ether Derivatives  [PDF]
Ling Dang, Qiang Li, Tongmei Ma, Sheng Sheng, Wei Zeng
International Journal of Organic Chemistry (IJOC) , 2011, DOI: 10.4236/ijoc.2011.14026
Abstract: An efficient BF3.OEt2-promoted benzylation of arenes and heteroarenes with various benzyl ether derivatives has been developed. This method provided alternative access to valuable diarylmethane in good yields under mild conditions via an easy work-up procedure.
A New Facile Route to Chlorination of Alcohols via Lewis Acid AlCl3  [PDF]
Hengchang Ma, Zhikang Bao, Lianhua Bai, Wei Cao
International Journal of Organic Chemistry (IJOC) , 2012, DOI: 10.4236/ijoc.2012.21004
Abstract: Halogenated aluminates AlCl3, applied as efficient chlorination reagent for hydroxyl groups of substitution alcohols is described. Primary and secondary benzylic alcohols could be transformed into corresponding aromatic halides with almost complete conversion and unique selectivity. As chlorination reagent, AlCl3 has an incomparable advantage over others, such as low material cost, commercial availability as well as convenient product isolation.
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