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151.
针对广义空间调制(GSM)系统中信号检测复杂度过高的问题,提出了一种基于相位判决的低复杂度检测算法。首先根据一种排序准则对天线组合进行排序,然后将排序后的天线组合中的符号向量依次通过基于相位判决的迫零(ZF)均衡器进行检测,最终得到星座调制符号和激活天线组合。分析和仿真结果表明,该检测算法可以有效缩小接收端的搜索范围,在提供与最大似然(ML)检测算法相近的误比特率(BER)性能的同时,计算复杂度降低了98%。  相似文献   
152.
研究目的:实现由传统的人工识别到自动识别土地利用格局空间尺度的方法创新,为优化区域土地利用格局提供科学依据。研究方法:基于分形理论,采用二阶导数对计盒维数模型进行改进和优化。研究结果:(1)研究区土地利用格局在900 m×900 m尺度上具有明显的分形特征;(2)1991年、2003年和2015年研究区土地利用格局表现为各土地利用类型之间空间作用力、分布均匀程度和内部联结性的大小不同,并呈现出空间相互关联关系复杂性;(3)1991—2015年,研究区土地利用格局空间相互关联关系变化特征明显,表现为土地利用格局中竞争强度强弱的差异。研究结论:(1)改进的计盒维数模型能够实现土地利用格局空间尺度的自动识别;(2)建立的计盒维数自动识别尺度模型,确定研究区土地利用格局空间尺度900 m×900 m是独立最小地理单元,也是分析土地利用格局变化的最优尺度。  相似文献   
153.
154.
在理论分析经济金融化影响城镇化机制的基础上,运用我国省际面板数据建立空间计量模型,并采用直接效应和间接效应分解的方法来探寻经济金融化对本区域和邻近区域城镇化发展的影响效应及特征。研究发现,经济金融化对本区域城镇化的影响存在着倒"U"型的非线性转换特征。当经济金融化水平未达到倒"U"型曲线的顶点以前,对该区域城镇化的影响效应显著为正;而其跨越"U"型曲线的顶点后,对该区域城镇化发展的负面效应便开始显现。但值得注意的是,其对邻近区域城镇化影响的非线性特征并不显著,而是存在显著的、线性的负向关系,会制约邻近区域城镇化的发展。此外,工业化和农业人力资本两个控制变量对本区域和邻近区域的城镇化影响效应均显著为正。  相似文献   
155.
In the framework of different countries' international comparison, the objective of this paper reflects research topic of investigation--the identification of small countries, revealing features of economic development and business growth in economic history context of small economies classification. The object of investigation focuses on West European and Nordic countries' small economies. The hypothesis of the article is that small states under consideration are developing as the business competitive peripheries areas due to the special Scandinavian capitalist model development characterized by high level of social capital. The statistical data base includes Organization of Economic Cooperation and Development indicators, World Bank parameters and Nordic transnational corporation's annual reports. The paper considers the following research questions: (1) the critical overview of the mainstream academicians opinions concerning different-scaled economies, (2) classification of small states and clarification of different groups of the small-scaled countries role in the world and regional economy through historical context, (3) estimates and variants of small countries' social-economic development in accordance with different parameters, (4) consideration of Nordic European countries coming to the business model of the competitive peripheral social-economic development. The main summing up conclusion is that small economies of Nordic Europe are converting nowadays into the experimental laboratory of the European and world economy due to the specific model of their social-oriented economic and business growth, their geopolitical location between developed European integration complex embracing presumably small-scaled states from one side and large-scaled emerging market economy of Asian continent from the other side.  相似文献   
156.
北京市休闲农业园区空间分布特征研究   总被引:1,自引:0,他引:1  
文章借助地理信息系统,利用调查的703个休闲农业园区的点位数据,对北京市休闲农业园区的空间分布特征进行了分析,为政府部门对休闲农业进行政策扶持,提供公共服务,以及有的放矢地进行休闲农业园区的提档升级进行决策支撑。从最邻近指数、洛伦兹曲线和地理集中指数以及基尼系数3个方面进行了空间分布类型的测定,结果显示北京市休闲农业空间布局类型是集聚型;利用核密度法、空间分布热点来分析空间分布密度,在密度较高的地区主要集中在昌平、顺义、海淀和通州,热点区域主要集中在昌平、海淀、顺义和怀柔;通过缓冲区分析和二次函数曲线拟合来分析观光园区点位与客源市场的关系,在与一级市场的关系来看,形成30~50km的高密度环,在与二级市场的关系来看,形成10~15km的高密度带,休闲园区分布随距离衰减的规律是先增加后减少;在交通网络密度方面,整体的路网密度较密集,呈现由中部向东西部逐步降低的趋势。从交通网络通达度来看,呈现环状分布兼块状分布相结合的趋势。网络交通度最高的园区分布在昌平、顺义还有海淀的一部分。结论:(1)北京的休闲农业园区发展已经达到了集聚程度,但集中程度不是很高,还有发展的潜力与空间。(2)密度较高的地方主要集中于昌平、顺义、海淀,在密度较高的地方交通网络通达度也较高,可以在密集程度较高的地方设立中转站或联络站点。(3)从距离客源市场的分布图分析,休闲农业的发展受客源市场影响较大。(4)交通网络密度,基本上按照圈层分布,要扩大休闲农业旅游市场范围,进一步增强休闲农业旅游的吸引力。  相似文献   
157.
The objective of this study is to identify the pathways of the potential impacts of the Sloping Land Conversion Program (SLCP) on household income and quantify these impacts along the identified pathways. We fulfill this objective by developing an integrated analytic framework and using data collected from Wuqi county of Shaanxi for the period 2004–2010. This integrated analytic framework enables us to formulate a structural equation model for testing hypotheses regarding the direct and indirect impacts of the SLCP. It is found that the direct effect of the SLCP on household income is positive but very small and insignificant, suggesting that retiring cropland has, at least, not reduced income from farming. Moreover, the SLCP has had a much higher and even increasing indirect impact on household income through promoting labor transfer and relaxing liquidity constraints. Overall, the SLCP's total impact on household income ranged from 3% in 2004 to 9% in 2010 excluding the insignificant direct impact. The research and policy implications of our work are discussed.  相似文献   
158.
This article argues for a reconceptualization of one of the most basic concepts in urban studies: the neighborhood. Traditionally neighborhoods have been understood as clearly bounded, quasi‐Westphalian containers or as ‘natural areas’ of urban community. But this approach is widely acknowledged to be under‐theorized. And it fails to account for the ways in which the production of neighborhood is inherently political and often conflictual. After reviewing the ways in which neighborhood has been used in urban sociology and urban planning, this article offers a critical conception of neighborhoods as ‘spatial projects’ on the submetropolitan scale. This approach captures the ways in which neighborhoods are not abstract spaces on a city map, but the uneven, unequal products of complex, ongoing struggles between various groups and institutions. This approach is developed through an ethnographic and historical case study of neighborhood formation in one part of Brooklyn, New York. The article concludes with a discussion of how the language of spatial projects refocuses urban research on the political and economic forces that produce neighborhood in the contemporary city.  相似文献   
159.
摘要:在现有农村土地产权制度下,土地及依附于其上的各类生产要素不具有充分交易的条件,进而因缺乏合格的交易客体而使农村金融交易呈现非对称状态。人民银行济南分行立足于满足枣庄流转土地和寿光蔬菜订单的需求,在谋求对称农村金融交易主体上寻求突破,较好顺应了农村土地规模化和集约化经营的主流趋势,对破解农村金融交易困境有一定借鉴意义。  相似文献   
160.
This paper presents a comparative case study of academic group leaders, active in three different scientific fields at a leading Swiss technical university. It examines the obstacles that prevent scientists from commercializing their technologies and how they can be reduced. Traditional models of technology transfer assume that scientists prefer either to 'go it alone' and become entrepreneurs (the inventor entrepreneur model) or to let go of their technologies to people interested in their commercialization (the surrogate entrepreneur model). The results of qualitative research suggest that these two models capture the extremes of a continuum populated by a variety of intermediate situations where scientists are unwilling completely to let go of their findings, but also do not want to become full time entrepreneurs. This results in considerable commercial potential that is unexploited. The Founding Angels approach might be a solution to this problem; it is designed for academics in these intermediate situations. The study contributes to the literature on university-industry technology transfer and should be useful for practitioners and scientists interested in maximizing the synergies between academia and industry.  相似文献   
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