共查询到20条相似文献，搜索用时 369 毫秒
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有限域Fq上一个周期序列的k错线性复杂度被定义为通过改变每个周期至多k个比特所得到的最小线性复杂度.给出有限域Fq上pn周期序列的k错线性复杂度的期望,其中p是一个奇素数,q是模p2的原根,并且1≤k≤(p-1)/2. 相似文献
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虾,蟹壳聚糖溶液粘度变化的研究 总被引：2，自引：0，他引：2
分别对虾、蟹壳聚糖溶液在不同浓度、p H值、温度下对其粘度变化的影响进行了研究 ,并对引起这些变化的原因进行了初步探讨 .结果表明 ,在溶液中蟹壳聚糖的降解速度比虾壳聚糖的降解速度快 ,在相同条件下虾壳聚糖溶液的粘度大于蟹壳聚糖溶液的粘度 .此结果对以壳聚糖为原料制备胶囊有着一定的理论意义和实际意义 相似文献
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针对基于用户的协同过滤推荐模型对搜索兴趣最近邻居准确度不高等问题,提出了一种时间上下文关联的智能推荐模型。该模型考虑了现实情况中顾客之间兴趣的时间同步性与顾客之间的相似性成正比的关系,并在模型中引入了时间衰减因子来表示这种关系,从而提高搜索兴趣最近邻居的准确度。实验结果表明,改进的时间关联推荐模型的准确度比协同过滤推荐模型的准确度提高了25％。 相似文献
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本文提出了一个带有双重反馈作用的异质herding模型,该模型假设金融市场是由不同大小和意愿的经纪人集团组成,两个不同集团发生交易或合并的成功率依赖上一次交易的市场波动程度,交易后亏损方发生翻转和分化的概率跟亏损程度有关.我们认为翻转和分化的概率也跟经纪人集团时市场的信念有关.为此,我们给经纪人集团一个参数k去表示他们对市场的信念程度.数值计算表明在我们的模型中动力学行为明显随k变化而变化,即信念能调节市场的演化. 相似文献
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1系统模型本文中我们考虑了一个具有n个发射和m个接收天线的移动通信系统。在每个时隙t,信号cti,i=1,2,…,n从n个发射天线同时发射,且所有的信号都有相同的发射周期T。在这里我们假设发射的信号是空时分组码。每个接收天线接收 相似文献
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常用视频压缩算法DCT在有效去除冗余信息同时却存在方块效应和"飞蚊噪声"。基于数学形态学帧内压缩算法采用了8比特面模型,先将最高层比特面分解出来进行编码,再分别对各个比特面按位数由高到低逐层分解,确定出对应的条件集,通过条件形态变换、条件形态骨架算法对图像进行编码。通过仿真,与常用算法比较,在相同压缩比下可提高视频质量,弥补了DCT算法在图像传输中的不足,在网络视频图像编解码及传输中具有实用意义。 相似文献
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文章首先建立一个室内导航模型,提出了一种基于概念格的室内导航算法,该算法基于位置-出口模式和形式概念分析的理论,使用概念格表示室内环境,并使用最近邻居关系结合A*算法来查找两个实体之间的最优路径。 相似文献
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人群工作协同进化动力学模型及模拟 总被引：2，自引：0，他引：2
依据组织行为学理论和协同进化原理,建立人群--工作协同进化动力学模型,并进行定性分析和模拟研究.在Lotka-Volterra模型的基础上,以协同商务工作为例,建立了虚拟团队与任务之间互动关系的系统动力学模型,并进行模型定性分析;利用Vensim对该模型进行模拟,并对稳态数据进行分析,包括对系统震荡周期、人群、工作密度等稳态数值的分析,探讨了对不同效率和不同复杂度任务下的人群工作系统互动管理决策方法. 相似文献
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通过扩展罗默三部门内生增长模型,依次将模仿与自主创新两种技术进步的方式引入研发部门建立一个后发经济体技术赶超模型。运用该模型对后发经济体技术赶超中的经济运行路径进行分析,结果发现中间品生产企业的价值变化与中间品种类数的变动之间的相互作用所构成的动力系统推动着后发经济体的技术进步沿着一定的路径运行。该路径会经历模仿与创新两个漩涡式的均衡点,赶超经济体想实现赶超就要跨越模仿均衡达到创新均衡。 相似文献
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在对2000—2018年中国先进制造业服务化对先进制造业全球价值链升级的影响进行实证分析的基础上，引入自主创新和模仿创新两类不同的技术创新，以检验其在上述影响中存在效应的差异。研究发现，先进制造业服务化对全球价值链升级具有显著促进作用；先进制造业服务化与模仿创新之间呈先促进、后抑制的倒“U”型关系；先进制造业服务化与自主创新之间呈先抑制、后促进的“U”型关系；知识资本投入在先进制造业服务化与模仿创新和自主创新中均存在调节效应，对自主创新产生促进效果，但对模仿创新产生负向影响。为进一步推动服务化进程，政府应鼓励推动先进制造业及服务业中的互动融合，并健全市场配置和运行机制，增强先进制造业技术、产品和市场自主创新能力。 相似文献
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《Research Policy》2019,48(9):103802
Technological imitation may play a crucial role in motivating firms to innovate. However, theoretical predictions and empirical findings on the role of imitation have not yet reached a consensus. One major gap in the previous studies is that the empirical tests are based on samples consisting of only one industry over a short period of time. This study uses a novel measure of industry-level technological imitation proxied by quick citations by competitors to examine the relationship between imitation and innovation. Using US patent data for the period 1977–2005, we find that there are inverted U-shaped relationships between the degree of industry-level technological imitation and industry-level innovation activities and between the degree of industry-level technological imitation and the value of firm-level innovation. Our results suggest that positive externalities from the interactions among firms during the innovation process outweigh the negative effects of free-riding concerns on firms’ innovation activities and incentives to innovate up to a high degree of technological imitation, while free-riding concerns outweigh the positive externalities when the level of technological imitation is extremely high. The sector-by-sector analyses show that the relationship between technological imitation and the quantity and market value of innovation are not very different across Pavitt sectors. A comparative analysis on the role of imitation between agglomerated and non-agglomerated industries suggests that the positive effect of a moderate level of imitation and the negative effect of an excessive level of imitation are more pronounced for agglomerated industries. The results suggest that creating innovation clusters, such as Silicon Valley in the United States and Shenzhen City in China, and allowing different innovators to cooperate, imitate and compete with each other would be very effective in promoting corporate innovation. However, an excessively high level of technological imitation is more detrimental for firms in innovation clusters because it lowers those firms’ incentives to innovate more radically. 相似文献
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How do knowledge-intensive business services (KIBS) protect their inventions from imitation by rival firms when choosing among various protection mechanisms? Data from the 2003 Statistics Canada Innovation Survey on services are used to investigate this issue by looking into complementarities, substitution and independence among eight protection mechanisms. A Multivariate Probit (MVP) model is estimated to take into account the fact that KIBS simultaneously consider many alternative intellectual property (IP) protection methods when they attempt to protect their innovations. Results show that patents, registration of design patterns, trademarks, secrecy and lead-time advantages over competitors constitute legal and informal methods that are used jointly. These complementarities suggest that IP protection mechanisms that are interdependent and reinforce each other to protect innovations from imitation by rival firms constitute a pattern on which firms rely to protect their innovations from imitation. A second pattern is based on the fact that KIBS rely on patents and complexity of designs as substitutes, and tend to use registration of design patterns and complexity of designs as substitutes in protecting their innovations from imitation. A third emerging pattern concerns protection mechanisms that are independent from each other and exhibit no synergy, and do not reinforce each other to protect innovations from imitation by other firms. 相似文献
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自主创新、技术模仿与地区经济增长研究 总被引：3，自引：1，他引：2
基于MRW(1992)模型,将企业研发投资分解为自主创新、国外技术引进模仿和国内技术转移,利用中国31个省市自治区1997~2005年的面板数据,实证分析了自主创新和技术模仿对地区经济增长的影响。 相似文献
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集群企业的模仿特征及模仿方式探析 总被引：1，自引：0，他引：1
对国内外关于企业模仿的相关研究进行了简要回顾,结合集群环境,对集群企业的特征进行了归纳并重点讨论了集群内企业模仿行为的五大特征,还从模仿源、模仿路径、模仿内容等具体分析了卫星式集群结构和网状式集群结构下企业不同的模仿方式,最后,作出简要总结并指出研究的不足及今后相关领域进一步研究的方向. 相似文献
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China's national innovative capacity 总被引：5，自引：0，他引：5
China is transforming itself into the workshop of the world, building an export-oriented national production system linked by global value chains to the world's leading economies. But to what extent is it laying the foundations for moving from imitation to innovation? In this first study of China's national innovative capacity, we extend earlier work conducted on the East Asian Tiger economies, and bring it up to the year 2005. We demonstrate a surge in patenting activity by Chinese firms and organizations since 2001, and analyze the drivers behind this, as well as the quality characteristics of the patenting - in terms of intensity, impact and links with the science base. We have some striking findings to report, including the strong role played by universities in the building of China's national innovative capacity over the last 15 years, and the puzzling apparent lack of contribution of the public sector in reinforcing China's national innovative capacity. On the latter point we suggest that the role of public sector institutions has been mixed, and only exerts its effects after reforms streamlined the system and brought many of the institutions into the private sector. 相似文献
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互联网与民间资本的结合产生了大众筹资模式(简称众筹),资助人不仅在众筹网站为创新项目提供资金,而且主动辅助项目的执行。如何利用资助人的公民行为提高项目实施绩效是一个重要的学术问题。本文基于价值共创、价值与满意度方面理论,采用问卷调查法研究资助人公民行为对满意度的作用,以及公民行为的影响因素。主要有三点贡献:1首次从价值共创角度分析众筹项目的执行过程;2揭示了资助人公民行为、社区收益与满意度的关系;3验证了感知的项目风险、项目新颖度、社会责任感对资助人公民行为的影响。 相似文献
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对于技术落后的企业,其缩小与技术先进企业之间技术差距的努力往往是从模仿开始．随着差距的不断缩小,具有超凡学习能力的技术落后企业将经历从纯粹的模仿到创造性模仿,再到局部创新,直至自主创新的整个赶超过程．由于技术差距主要是企业间的知识差异造成的,因此获取知识,尤其是技术核心知识将是实现赶超目的的关键．在这一过程中,组织学习是获取、利用以及扩散知识的主要手段．由于知识本身的特性,从模仿到创新的各个阶段将有不同的知识学习的重点,这要求有不同的组织学习方式与目标知识相适配以有效地获取、吸收和利用知识,同时企业从一个阶段向另一个阶段迈进时,随着目标知识的变化,与之相适配的组织学习方式也会相应地进行转化． 相似文献