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基于依存分析的中文时间表达式类型判定 被引量:2
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作者 肖升 何炎祥 李勇帆 《计算机应用》 CSCD 北大核心 2013年第6期1582-1586,共5页
某些"基数词+时间单位词"组成的中文时间表达式在不同语境中可能表现为时点式,也可能表现为时段式。为自动判定中文时间表达式的类型,提出一种基于依存分析的判定方法。该方法首先借助依存分析考察中文时间表达式在句中所受... 某些"基数词+时间单位词"组成的中文时间表达式在不同语境中可能表现为时点式,也可能表现为时段式。为自动判定中文时间表达式的类型,提出一种基于依存分析的判定方法。该方法首先借助依存分析考察中文时间表达式在句中所受的句法约束,然后将这些约束转化为具有可计算性的依存规则,最后利用依存规则对中文时间表达式的类型进行判定。实验结果显示,在此方法中,时间表达式确认的正确率、召回率、F值分别达到82.3%、88.1%和85.1%;时间表达式类型判定的正确率、召回率、F值分别达到77.1%、82.5%和79.7%。 展开更多
关键词 中文时间表达 时点式 时段 依存分析 类型判定
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Shifted first arrival point travel time NMO inversion 被引量:2
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作者 谭尘青 吴燕冈 +2 位作者 韩立国 巩向博 崔杰 《Applied Geophysics》 SCIE CSCD 2011年第3期217-224,240,241,共10页
Serious stretch appears in shallow long offsset signals after NMO correction. In this article we study the generation mechanism of NMO stretch, demonstrate that the conventional travel time equation cannot accurately ... Serious stretch appears in shallow long offsset signals after NMO correction. In this article we study the generation mechanism of NMO stretch, demonstrate that the conventional travel time equation cannot accurately describe the travel time of the samples within the same reflection wavelet. As a result, conventional NMO inversion based on the travel time of the wavelet's central point occurs with errors. In this article, a travel time equation for the samples within the same wavelet is reconstructed through our theoretical derivation (the shifted first arrival point travel time equation), a new NMO inversion method based on the wavelet's first arrival point is proposed. While dealing with synthetic data, the semblance coefficient algorithm equation is modified so that wavelet first arrival points can be extracted. After that, NMO inversion based on the new velocity analysis is adopted on shot offset records. The precision of the results is significantly improved compared with the traditional method. Finally, the block move NMO correction based on the first arrival points travel times is adopted on long offset records and non-stretched results are achieved, which verify the proposed new equation. 展开更多
关键词 long offset NMO stretch first arrival point travel time equation NMO inversion
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Checkpointing Scheme for Relevant Distributed Real-Time Tasks 被引量:1
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作者 方明 袁由光 +1 位作者 杨升春 赵晓勇 《Journal of Donghua University(English Edition)》 EI CAS 2005年第3期23-27,共5页
A checkpointing scheme for relevant distributed real-time tasks which can be scheduled as a DAG is proposed. A typical algorithm, OSA, is selected for DAG scheduling. A new methods based a new structure, Scheduled Clu... A checkpointing scheme for relevant distributed real-time tasks which can be scheduled as a DAG is proposed. A typical algorithm, OSA, is selected for DAG scheduling. A new methods based a new structure, Scheduled Cluster Tree, is presented to calculate the slack time of each task in the task cluster. In the checkpointing scheme, the optimal checkpoint intervals which minimize the approximated failure probability are derived formally and validated experimentally. The complexity of approximated failure probability is quite small compared with that of the exact probability. Meanwhile, the consistency of the checkpointing is discussed also. 展开更多
关键词 CHECKPOINT task scheduling DAG scheduled clusters tree
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Quantum Polynomial-Time Fixed-Point Attack for RSA 被引量:3
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作者 Yahui Wang Huanguo Zhang Houzhen Wang 《China Communications》 SCIE CSCD 2018年第2期25-32,共8页
Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography. In particular, the security of widely used public-key cryptosystems merits d... Security analysis of public-key cryptosystems is of fundamental significance for both theoretical research and applications in cryptography. In particular, the security of widely used public-key cryptosystems merits deep research to protect against new types of attacks. It is therefore highly meaningful to research cryptanalysis in the quantum computing environment. Shor proposed a wellknown factoring algorithm by finding the prime factors of a number n =pq, which is exponentially faster than the best known classical algorithm. The idea behind Shor's quantum factoring algorithm is a straightforward programming consequence of the following proposition: to factor n, it suffices to find the order r; once such an r is found, one can compute gcd( a^(r/2) ±1, n)=p or q. For odd values of r it is assumed that the factors of n cannot be found(since a^(r/2) is not generally an integer). That is, the order r must be even. This restriction can be removed, however, by working from another angle. Based on the quantum inverse Fourier transform and phase estimation, this paper presents a new polynomial-time quantum algorithm for breaking RSA, without explicitly factoring the modulus n. The probability of success of the new algorithm is greater than 4φ( r)/π~2 r, exceeding that of the existing quantum algorithm forattacking RSA based on factorization. In constrast to the existing quantum algorithm for attacking RSA, the order r of the fixed point C for RSA does not need to be even. It changed the practices that cryptanalysts try to recover the private-key, directly from recovering the plaintext M to start, a ciphertext-only attack attacking RSA is proposed. 展开更多
关键词 information security cryptogra-phy RSA fixed-point quantum computing
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Multi-Gradient Routing Protocol for Wireless Sensor Networks 被引量:3
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作者 Ying Qiu Shining Li +2 位作者 Zhigang Li Yu Zhang Zhe Yang 《China Communications》 SCIE CSCD 2017年第3期118-129,共12页
Sensor networks tend to support different traffic patterns since more and more emerging applications have diverse needs. We present MGRP, a Multi-Gradient Routing Protocol for wireless sensor networks, which is fully ... Sensor networks tend to support different traffic patterns since more and more emerging applications have diverse needs. We present MGRP, a Multi-Gradient Routing Protocol for wireless sensor networks, which is fully distributed and efficiently supports endto-end, one-to-many and many-to-one traffic patterns by effectively construct and maintain a gradient vector for each node. We further combine neighbor link estimation with routing information to reduce packet exchange on network dynamics and node failures. We have implemented MGRP on Tiny OS and evaluated its performance on real-world testbeds. The result shows MGRP achieves lower end-to-end packet delay in different traffic patterns compared to the state of the art routing protocols while still remains high packet delivery ratio. 展开更多
关键词 wireless sensor network routing protocol multi-gradient end-to-end traffic pattern
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Research on the Scientific Meaning of Rule of Law in China
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作者 Zhen Liu 《Review of Global Academics》 2015年第2期525-527,共3页
Beyond the existing academic viewpoints, clarifying the scientific meaning of the rule of law in China in the binary interaction between subject and object is the prerequisite for reifying the rule of law in China fro... Beyond the existing academic viewpoints, clarifying the scientific meaning of the rule of law in China in the binary interaction between subject and object is the prerequisite for reifying the rule of law in China from an abstract symbol to a logic in action. The subject dimension of rule of law in China subsumes the legal consciousness, self confidence, independence and self-improvement of the subject. The object dimension of the rule of law in China focuses the relation mode and governance pattern between right and power. In the dimension of time, the rule of law in China is the unification of history and reality of China model. In the dimension of space, the rule of law in China is committed to seeking the right to speech, governance, management and development from the perspective of globalization. 展开更多
关键词 Rule of law in China GOVERNANCE PATTERN
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Global exponential stability of cellular neural networks with multi-proportional delays 被引量:10
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作者 Liqun Zhou Yanyan Zhang 《International Journal of Biomathematics》 2015年第6期1-17,共17页
In this paper, a class of cellular neural networks (CNNs) with multi-proportional delays is studied. The nonlinear transformation yi(t) = xi(et) transforms a class of CNNs with multi-proportional delays into a c... In this paper, a class of cellular neural networks (CNNs) with multi-proportional delays is studied. The nonlinear transformation yi(t) = xi(et) transforms a class of CNNs with multi-proportional delays into a class of CNNs with multi-constant delays and time- varying coefficients. By applying Brouwer fixed point theorem and constructing the delay differential inequality, several delay-independent and delay-dependent sufficient conditions are derived for ensuring the existence, uniqueness and global exponential stability of equilibrium of the system and the exponentially convergent rate is estimated. And several examples and their simulations are given to illustrate the effectiveness of obtained results. 展开更多
关键词 Cellular neural networks proportional delay global exponential stability Brouwer fixed point theorem delay differential inequality.
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