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11.
Florentina Tone 《Numerical Methods for Partial Differential Equations》2007,23(5):1235-1248
In this article we study the stability for all positive time of the Crank–Nicolson scheme for the two‐dimensional Navier–Stokes equations. More precisely, we consider the Crank–Nicolson time discretization together with a general spatial discretization, and with the aid of the discrete Gronwall lemma and of the discrete uniform Gronwall lemma we prove that the numerical scheme is stable, provided a CFL‐type condition is satisfied. © 2007 Wiley Periodicals, Inc. Numer Methods Partial Differential Eq, 2007 相似文献
12.
考虑自有平台和第三方平台两种分时租赁方式,将汽车质量划分为性能质量和环境质量,构建销售模式、纯分时租赁模式和混合模式下的产品线策略模型,研究制造商产品线策略与商业模式之间的相互作用。研究发现,同品牌产品间竞争和合并效应是分时租赁模式影响产品线策略的两个关键因素。同品牌产品间竞争的加剧和合并效应的增大都会激励企业选择性能更好的车型而忽略其环境表现。分时租赁模式能同时改进利润与产品环境表现,但存在条件:当消费者价格敏感性较低时,使用成本高且合并效应小是实现同时改进的条件;当消费者价格敏感较高时,使用成本低且合并效应小则是同时改进的条件。 相似文献
13.
针对现有船舶过闸排队规则的欠缺,基于“限时服务规则”,构建复线船闸多目标双层优化调度模型:上层模型用于获得两个闸室安全区域的船舶排布可行方案;下层模型用于获得不同船舶排布可行方案的优化闸次数。下层模型分两个阶段完成:对符合“限时服务规则”的船舶,构建以闸次最少为目标的0-1规划模型,获得此类船舶安排的闸次;对其余船舶按照“先到先服务规则”,构建以闸次最少、闸室利用率最大为目标的多目标决策模型,获得不同船舶排布可行方案应该安排的频次。以位于江苏省干线航道上的某复线船闸某日24小时内过闸船舶的数据为例,计算结果表明:采用本文优化模型获得的优化方案与“经验编排方式”相比,两座船闸各节约2个闸次,两个船闸的平均闸室利用率分别提高了3.66和4.72个百分点。 相似文献
14.
Sankaran Vijayalakshmi Alagumariappan Paramasivam Sankaran Sakthivel Swamynathan Kudiyarasan Esakky Sankaran Velmurugan Nagarajan 《International Journal of Communication Systems》2023,36(7):e5447
In this work, a digital differential transmitter based on low-power wireless compensation transceiver for body channel communication (BCC) is proposed. Further, the proposed transceiver is composed of Touch Status Detection Unit (TSDU), Wireless Status Compensation Unit (WSCU), and a reconfigurable preamplifier. Initially, the human body channel environment for wireless communication is investigated based on properties from 1 to 100 MHz. Further, the turbo code-based encoding scheme is used to encode the data before transferring the data on the transmitter side. Also, the proposed error-correcting parallel turbo decoder using a modified step-by-step algorithm is presented. The turbo code-based decoding scheme is used to recover the error-free transmitted data at the receiver side. Results demonstrate that the proposed BCC transceiver is designed using 90 nm CMOS technology and it is observed that the proposed BCC transceiver has utilized an area of 600mm2. Also, the maximum data rate achieved by a proposed BCC transceiver was 100 Mbps, and the overall transceiver power consumption is 0.42 mW, and energy for communication is 0.02 nj/b. 相似文献
15.
Yu Chen 《Transactions of the American Mathematical Society》1996,348(9):3733-3743
We demonstrate a one to one correspondence between the irreducible projective representations of an affine Kac-Moody group and those of the related loop group, which leads to the results that every non-trivial representation of an affine Kac-Moody group must have its degree greater than or equal to the rank of the group and that the equivalence appears if and only if the group is of type for some . Moreover the characteristics of the base fields for the non-trivial representations are found being always zero.
16.
Simultaneous thermogravimetry–differential thermal analysis (TG–DTA) and gas and liquid chromatography with mass spectrometry detection have been used to study the kinetics and decomposition of 2-hydroxybenzoic acid, 2-carboxyphenyl ester, commercially known as salsalate. Samples of salsalate were heated in the TG–DTA apparatus in an inert atmosphere (100 ml min−1 nitrogen) in the temperature range 30–500 °C. The data indicated that the decomposition of salsalate is a two-stage process. The first decomposition stage (150–250 °C) had a best fit with second-order kinetics with Ea=191–198 kJ/mol. The second decomposition stage (300–400 °C) is described as a zero-order process with Ea=72–80 kJ/mol. The products of the decomposition were investigated in two ways:
- (a)Salsalate was heated in a gas chromatograph at various isothermal temperatures in the range 150–280 °C, and the exit gas stream analyzed by mass spectrometry (GC–MS). This approach suggested that salsalate decomposes with the formation of salicylic acid, phenol, phenyl salicylate, and cyclic oligomers of salicylic acid di- and tri-salicylides.
- (b)One gram samples of salsalate were heated in a vessel under nitrogen to 150 °C, and the residues were analyzed by liquid chromatography–mass spectrometry (LC–MS). The major compound detected was a linear tetrameric salicylate ester.
17.
18.
一种改进的一致性扩散图像增强方法 总被引:4,自引:0,他引:4
一致性扩散是分析图像中定向结构的重要的预处理步骤,现有的一致性扩散图像增强方法难以识别图像中的弱边界。本文提出了一种改进的扩散方法,该方法构建了一种结合二阶方向导数信息的结构张量,能够精确分析图像中的复杂弱边界,同时与经典结构张量互为补充以检测图像的强边界。在此基础上设计了新的扩散张量,并采用了基于(加性分裂算子AOS)策略的数值计算方法。通过对比实验证明,该文算法的效果良好并具有很高的效率, 实现了在去除噪声的同时精确保护图像中的强弱边界。 相似文献
19.
In most (t,n)-Multi-secret sharing ((t,n)-MSS) schemes, an illegal participant, even without any valid share, may recover secrets when there are over t participants in secret reconstructions. To address this problem, the paper presents the notion of Group ori-ented (t,m,n)-multi-secret sharing (or (t,m,n)-GOMSS), in which recovering each secret requires all m (n ≥ m ≥ t) participants to have valid shares and actually participate in secret reconstruction. As an example, the paper then pro-poses a simple (t,m,n)-GOMSS scheme. In the scheme, every shareholder has only one share; to recover a secret, m shareholders construct a Polynomial-based randomized component (PRC) each with the share to form a tightly coupled group, which forces the secret to be recovered only with all m valid PRCs. As a result, the scheme can thwart the above illegal participant attack. The scheme is simple as well as flexible and does not depend on conventional hard problems or one way functions. 相似文献
20.
随着多跳蜂窝网的发展,协作通信成为热点问题,其中节点激励策略是研究重点.分析比较了Ad Hoc网络和多跳蜂窝网络中的激励策略.根据每种策略的优缺点,详细阐述了实现节点激励策略的关键因素,指出结合信誉和计费和有安全保证的激励策略才是下一代多跳网络节点协作问题的关键. 相似文献