排序方式: 共有118条查询结果,搜索用时 8 毫秒
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许多自动指纹识别系统在注册阶段对于每个用户存储同一手指的多个模板指纹,在认证阶段将输入的指纹和存储在模板库中的相应手指的多个模板指纹进行比对。提出了将多个模板指纹的特征进行拼接的方法,将多个模板指纹拼接成一个模板指纹。这样,在认证阶段可以减少和输入指纹进行比对的模板个数,加快了比对速度。同时,拼接而成的模板指纹比单个模板指纹的特征丰富,有利于提高识别的正确率。实验测试表明,方法能够提高系统的识别性能。 相似文献
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在分析了IDEF0基本模型及其军用模型的基础上,结合面向对象的分析方法,提出了一个通用的指挥控制对象的概念模型,并采用形式化描述语言LOTOS(LanguageofTemporalOrderingSpecification)和基于动作的时序逻辑ACTL(ActionBasedTemporalLogical)对系统进行了形式化描述和性质验证。这为C4ISR系统的需求描述和验证提供了一种新的思路和方法。 相似文献
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通常商用体系结构模拟器不开源,仿真过程中无法直接获取中间结果.提出了一种基于核心数据区监视的交叉验证方法,可将体系结构模拟器运行过程中核心数据区的变化情况提取出来,用以支持该模拟器与寄存器传输级代码的模拟结果进行交叉比对,快速精确定位两者的执行差异,提高验证人员的查错效率.实验分析和实际应用表明,本方法比传统方法可将查... 相似文献
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静电放电模拟器电流波形校验装置研究 总被引:7,自引:2,他引:7
研制了符合国际电工委员会IEC61000-4-2标准的ESD模拟器电流校验系统。该系统能自动采集ESD电流波形,计算上升时间、峰值电流、30ns时电流。60ns时电流等参数。该系统已用于我国静电计量测试站对静电放电电流波形的校验工作。 相似文献
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“Evergreening” is a strategy wherein an innovative pharmaceutical firm introduces an upgrade of its current product when the patent on this product expires. The upgrade is introduced with a new patent and is designed to counter competition from generic manufacturers that seek to imitate the firm's existing product. However, this process is fraught with uncertainty because the upgrade is subject to stringent guidelines and faces approval risk. Thus, an incumbent firm has to make an upfront production capacity investment without clarity on whether the upgrade will reach the market. This uncertainty may also affect the capacity investment of a competing manufacturer who introduces a generic version of the incumbent's existing product but whose market demand depends on the success or failure of the upgrade. We analyze a game where capacity investment occurs before uncertainty resolution and firms compete on prices thereafter. Capacity considerations that arise due to demand uncertainty introduce new factors into the evergreening decision. Equilibrium analysis reveals that the upgrade's estimated approval probability needs to exceed a threshold for the incumbent to invest in evergreening. This threshold for evergreening increases as the intensity of competition in the generic market increases. If evergreening is optimal, the incumbent's capacity investment is either decreasing or nonmonotonic with respect to low end market competition depending on whether the level of product improvement in the upgrade is low or high. If the entrant faces a capacity constraint, then the probability threshold for evergreening is higher than the case where the entrant is not capacity constrained. Finally, by incorporating the risk‐return trade‐off that the incumbent faces in terms of the level of product improvement versus the upgrade success probability, we can characterize policy for a regulator. We show that the introduction of capacity considerations may maximize market coverage and/or social surplus at incremental levels of product improvement in the upgrade. This is contrary to the prevalent view of regulators who seek to curtail evergreening involving incremental product improvement. © 2016 Wiley Periodicals, Inc. Naval Research Logistics 63: 71–89, 2016 相似文献
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In this paper,a novel launch dynamics measurement system based on the photoelectric sensor pair is built.The actual muzzle time(i.e.a time duration that originates from the initial movement to the rocket's departure from the muzzle)and the muzzle velocity are measured.Compared with the classical methods,the actual muzzle time is obtained by eliminating the ignition delay.The comparative analysis method is proposed with numerical simulations established by the transfer matrix method for multibody systems.The experiment results indicate that the proposed measurement system can effectively measure the actual muzzle time and reduce the error of classical methods,which match well with the simulation results showing the launch dynamics model is reliable and helpful for further analysis and design of the MLRS. 相似文献
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Flexible capacity strategy in an asymmetric oligopoly market with competition and demand uncertainty 下载免费PDF全文
This article studies flexible capacity strategy (FCS) under oligopoly competition with uncertain demand. Each firm utilizes either the FCS or inflexible capacity strategy (IFCS). Flexible firms can postpone their productions until observing the actual demand, whereas inflexible firms cannot. We formulate a new asymmetrical oligopoly model for the problem, and obtain capacity and production decisions of the firms at Nash equilibrium. It is interesting to verify that cross‐group competition determines the capacity allocation between the two groups of firms, while intergroup competition determines the market share within each group. Moreover, we show that the two strategies coexist among firms only when cost differentiation is medium. Counterintuitively, flexible firms benefit from increasing production cost when the inflexible competition intensity is sufficiently high. This is because of retreat of inflexible firms, flexibility effect, and the corresponding high price. We identify conditions under which FCS is superior than IFCS. We also demonstrate that flexible firms benefit from increasing demand uncertainty. However, when demand variance is not very large, flexible firms may be disadvantaged. We further investigate the effects of cross‐group and intergroup competition on individual performance of the firms. We show that as flexible competition intensity increases, inflexible firms are mainly affected by the cross‐group competition first and then by the intergroup competition, whereas flexible firms are mainly affected by the intergroup competition. Finally, we examine endogenous flexibility and identify its three drivers: cost parameters, cross‐group competition, and intergroup competition. © 2017 Wiley Periodicals, Inc. Naval Research Logistics 64: 117–138, 2017 相似文献