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1.
提出了一种由单形规范线性分段(SCPWL)函数与记忆多项式级联的数字预失真器,并给出了复数域两步最小二乘参数辨识算法。不同于以往一种预失真器适用一种功放模型的情况,所提的预失真算法利用SCPWL函数的分段特性以及记忆多项式的非线性记忆特性,在完成参数辨识的同时自动地调整结构,可适用于传统以及强非线性新型功放模型的线性化补偿。将所提预失真器分别应用于传统记忆多项式、两箱模型以及新型包络跟踪功放。经过计算机仿真,功放输出的幅频特性和频谱曲线表明所提预失真器能够有效地补偿多种功放的非线性特性。算法仿真比较结果也表明,针对包络跟踪功放,所提复数两步最小二乘算法的邻道泄漏比(ACLR)可改善约35 dB,性能优于最小均方(LMS)类算法约30 dB。  相似文献   
2.
周霞  王楠  毕添宇  陈震  季鹏 《城市发展研究》2021,28(6):中插1-中插7
国家级新区是国家区域空间生产策略的体现,新时期高质量发展对其空间优化提出新要求.基于产城融合、区域协同与双效提升的高质量发展目标体系,构建国家级新区空间优化效果—效率双评价四分图模型,比较分析浦东、滨海等6个国家级新区2011~2017年空间优化水平.研究发现:(1)6个国家级新区空间优化水平整体呈现马太效应,低效果—低效率的新区间差距呈扩大趋势.(2)国家级新区空间优化水平存在南高北低的区域差异,南部4个新区中,2010年前成立的新区空间优化水平更高.(3)国家级新区空间优化效果与效率总体均值呈现类雁形与"乀"形变化.从以动态评价赋能精准施策、以绿色创新推动产城融合、以开放协调带动新区合作、以双效提升引导差异化发展等方面提出国家级新区空间优化的建议.  相似文献   
3.
Drawing upon the research in institutional theory and comparative capitalism, the present study investigates how cross-national differences in the political, business, and economic institutional contexts of the United States, Italy, and Japan are associated with the ways in which companies in each of these countries prioritize and engage in their stakeholder engagement activities (SEAs). Using Porter and Kramer's framework, which classifies corporate social responsibility (CSR) activities as falling into four categories (good citizenship, mitigating harm from value chain, transforming value chain activities, and strategic philanthropy), we investigate how companies in the United States, Japan, and Italy prioritize and engage in these four SEAs. An analysis of data collected from 340 companies across these countries reveals that while companies in each of these three countries undertake the four types of SEAs, the prioritization and prevalence of the four types of SEAs vary from one country to the other, in ways that align with the prevailing institutional contexts of each country. The results contribute to a more nuanced understanding of why and how companies' approaches to CSR differ across countries. From a practitioner's perspective, the findings highlight the cultural specificity of CSR, implying that despite the global nature of CSR, the implementation of CSR needs to be tailored to a country's context.  相似文献   
4.
杨谱  刘军  常维 《财经研究》2018,(2):44-57
户籍制度是我国劳动力流动的主要障碍.那么,当前我国的户籍扭曲程度几何?户籍制度放松对经济又会有怎样的影响?对这些问题的回答将有助于政府评估户籍制度改革的空间和经济效益.文章在Hansen和Prescott(2002)的两部门劳动力流动模型基础上,将工人分为农业和非农户口,引入户籍扭曲因子,构建两部门两类工人的户籍扭曲模型;然后,使用1984?2013年宏观经济数据度量户籍扭曲程度,并对2013年我国户籍制度逐渐放松过程中经济变量的变化进行模拟;最后,文章建立了包含"农业与非农"和"本地与外地"户籍差异的省份异质性户籍扭曲模型.研究表明:(1)经济和户籍制度改革的不同步导致了1984?2013年我国户籍扭曲程度呈现倒"U"形变化,且相较于韩国尚有较大的改善空间;(2)以韩国为参照,若2013年我国户籍制度完全放开,经济达到均衡时,农业部门和非农部门的就业人数将分别下降58.83%和上升26.92%,工资率将分别上升19.44%和下降6.77%,社会增加值将增长15.33%,这说明社会经济效率将得到提升,贫富差距将缩小.文章丰富和完善了户籍扭曲的理论模型,从减少劳动力流动摩擦的视角为政府制定相关政策提供了参考.  相似文献   
5.
This study examines how venture capital (VC) firms terminate investments in an emerging economy context. We contend that due to the weak institutional environment, it is appropriate to draw on insights from power and social relation perspectives for a better understanding of the phenomenon. Specifically, we argue that a termination decision hinges on not only the dependence relationship between a VC firm and its portfolio companies, but also the social relationships among VC firms. Event history analyses of approximately 12,000 VC deals made in China between 2001 and 2012 reveal that when a VC firm has a greater number of investments in an industry, it is more likely to terminate investments on a portfolio company in that industry. Moreover, such effect on termination is moderated by the focal VC's embeddedness with its syndicate partners and collaboration opportunities with other VC firms outside the immediate access of the syndicate partners. Our study sheds light on research on VC decision making in emerging markets by integrating insights from resource dependence relationships and interorganizational network characteristics.  相似文献   
6.
Using data from one of Australia's largest thoroughbred auction houses, we investigate the price determinants of thoroughbred yearlings sold at auction. We include novel key variables to construct hedonic pricing models and examine the relative role of stud fees compared to the wide range of attributes in the pricing of yearlings. We find that the price effect of stud fees is influenced by the value buyers place on both the characteristics of sires and the characteristics of sire side siblings. The findings imply that the quality of dams a sire has been matched within the breeding market has consequential effects on yearling prices through the sire's stud fee and progeny.  相似文献   
7.
Unlike most of the literature that examines the relationship between corporate philanthropy and financial performance, this study investigates the mechanisms through which corporate socially responsible behaviors produce financial outcomes. We propose that corporate philanthropy improves corporate competitiveness by eliciting positive responses from stakeholders, who assess a firm’s philanthropic contribution in relation to its rivals to determine what level of support they wish to provide to the firm. We predict that a firm’s philanthropy relative to its rivals has a positive effect on its product market competitiveness, and that this positive effect is moderated by three conditions that influence stakeholder response: stakeholder attention to philanthropy, its perceived legitimacy, and expectations of corporate giving. Our predictions are generally supported by our analyses. Overall, this paper shows that strategic philanthropy has a quantitative dimension, and firms obtain the market competitiveness associated with corporate philanthropy by integrating their rivals’ positions into their decision making.  相似文献   
8.
清徐县优势农业与旅游业协调发展研究   总被引:1,自引:0,他引:1  
[目的]发展优势农业是改造传统农业,加快农业现代化的有效途径之一,旅游业作为国民经济新的增长点,两者协调发展更有利于增加农民收入,促进新农村建设,同时也是农村社会经济可持续发展的必然要求。[方法]文章通过文献查阅法了解清徐县优势农业葡萄及葡萄文化旅游业等方面的相关研究及研究成果,结合实证分析法通过协调发展度函数构建模型对清徐优势农业协调旅游业发展进行定量分析。[结果]清徐县优势农业和旅游业的综合评价指数从2004年的0.118 6上升到2016年的0.985 8,总体呈上升趋势,同时协调度13年间,2004~2008年介于0.221 5~0.490 5之间,处于失调发展阶段,2009年为过渡阶段,协调度为0.524 3,2010~2015年协调度介于0.626 7~0.685 8之间,处于初级协调发展水平,2016年协调度为0.701 7,发展到中级协调发展水平。优势农业与旅游业协调发展有利于区域经济水平的提高和农业收入的增加。[结论]推动优势农业与旅游业协调发展,清徐县需加大散户经营管理力度,切实有效地解决散户存在的实际问题,夯实优势农业的基础,为旅游业发展提供更大的发展空间。  相似文献   
9.
Research Summary: This study addresses a theoretical dilemma regarding how alliance network constraint (reflected by network cohesion) affects a firm’s alliance formation with new partners. Using a network pluralism approach, we separate a firm’s ego alliance network into two activity‐based networks—an exploratory network and an exploitative network—based on the primary value chain activity involved in each alliance. We argue that the cohesion of exploratory or exploitative networks has an inverted U‐shaped effect on the addition of new partners in the same activity‐based network, and a positive effect on the addition of new partners in the other network. Results based on data from the biotechnology industry largely support our predictions with one exception. Our study contributes to both scholarly understanding of network embeddedness and alliance practice. Managerial Summary: The structure of firms’ ongoing alliance networks may have paradoxical implications for their efforts to search for and form alliance with new partners. That is, when a firm’s alliance partners are tightly connected with each other, the cohesive network tends to both encourage and impede the focal firm to add new partners. We resolve this dilemma by showing that when a firm is deeply entrenched in a cohesive alliance network conducting a certain type of activities (e.g., R&D activities), it may not easily add new R&D alliance partners. However, it may still be able to escape from the cohesive R&D alliance network by seeking new partners conducting other activities (e.g., manufacturing activities).  相似文献   
10.
高峻 《物流科技》2003,26(4):29-31
供应链管理作为一种新型的企业关系管理模式在现代市场竞争中为企业生存与发展提供了一种工具。本文针对协作型企业供应链管理进行了研究。协作型企业供应链由于其业务联系上的紧密性与其他供应链有所不同,在生产计划制定上强调生产计划的一致性与协调性,核心企业与供应企业在生产计划制定方面的信息共享;在销售管理上强调企业与销售商集成式管理。  相似文献   
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