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排序方式: 共有1347条查询结果,搜索用时 30 毫秒
1.
为了加快低密度奇偶校验(LDPC)码的译码速度,有效改善LDPC码的译码性能,针对校验节点更新过程中的对数似然比(LLR)值的大小,设计了一种LDPC码的动态加权译码方法。以IEEE 802.16e标准的奇偶校验矩阵为例,根据LLR值的变化规律,利用增长因子和抑制因子对和积译码算法和最小和译码算法进行动态加权。仿真结果显示,基于动态加权的译码方法相对于传统译码方法误码率都有明显改进,译码复杂度也有所降低。  相似文献   
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This study aims to examine the motives behind retailers’ post-entry expansion in foreign markets. Through case studies of eleven participating luxury fashion retailers in China, qualitative data was collected from twenty-two executive interviews. Although their initial market entry was driven by both reactive (push) and proactive (pull) factors, the motives behind their post-entry expansion have become predominantly proactive, especially long-term growth strategies, the ambition to extend their brands and retail formats to more cities, and the experiences gained in entry markets. The desire to optimize the retail store portfolio through multiple channel strategies have slowed down the expansions of physical stores.  相似文献   
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UxDMA算法是一种高效的集中式算法,是用于时分多址、频分多址和码分多址信道分配的统一算法。在UxDMA的基础上,利用多波束天线的多波束形成能力,针对低时延定向ad hoc网络提出了一种集中式调度算法——CLSM(Centralized Low-delay Scheduling Algorithm Based on Multi-beam Antennas)。CLSM通过不同时延等级限制的报文来比较着色后发送链路的优先级,优先选择高优先级链路传输。通过仿真验证了CLSM的性能:与UxDMA相比,该算法在多时延限制的发送端调度中表现出了更好的吞吐量和时延性能。  相似文献   
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Regulators have been paying increasing attention to governing and steering market fluctuations, with their role in shaping the economic cycle being ever more crucial. The combined effect of the financial and sovereign debt crises, as well as the approach to the zero lower bound, has made actions even more pressing, forcing the European Central Bank to resort to unconventional instruments to revive the economies and counter deflationary pressures. By using a combined event study and panel regression methodology, we investigate whether European Monetary Union equity markets react heterogeneously to standard and non-standard European Central Bank policy innovations. Our results show that conventional policies unevenly affect financial indices in the Eurozone and, hence, are bound to generate asymmetries that reflect on real economies, while unconventional measures, albeit with different intensities, exercise a homogeneous pressure on all markets. Our evidence highlights the beneficial impact of unconventional measures and suggests that they can play a useful role even in non-crisis times.  相似文献   
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This paper examines consumption risk sharing among 16 regions in South Korea over the 2000–2016 period. The empirical results show that 91.8 percent of shocks to gross regional domestic product are smoothed in South Korea. Capital markets, the tax‐transfer system and credit markets absorb 29.9, 28.9 and 33.0 percent of shocks to gross regional domestic product, respectively. Most notably, South Korea relies more on credit markets for risk sharing than capital markets, an opposite pattern to advanced countries like the USA, Canada and Australia. Furthermore, the patterns of consumption risk sharing are different before and after the 2007–2008 global financial crisis, and differences in regional industrial structure and local development can influence these patterns. This paper attempts to infer the connection between these findings and both the rapid economic growth of South Korea and the Asian and global financial crises.  相似文献   
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《The World Economy》2018,41(3):674-698
We examine the interest rate sensitivity of both deposits and credits at Islamic and conventional banks in Turkey. We find that the bank lending channel is especially operative for Islamic banks. Impulse responses for conventional and Islamic banks reveal that Islamic bank depositors’ sensitivity to policy rate changes is substantially larger than that of conventional bank depositors. Next to heavily dependence on deposit funding, we consider that inertia in Islamic bank deposit rates impedes these banks to keep those depositors who consider the opportunity cost of monetary policy rates is unbearable. On the lending side, we obtain similar results, implying that tight monetary policy leads to a larger contraction in Islamic bank credits. This finding is a reflection of the favourable attitude of Islamic banks towards small and medium‐sized enterprise (SME) financing. When similar relationships are analysed for currency and inflation shocks, we again find larger responses for Islamic banks showing the cyclical nature of SME credits.  相似文献   
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多径效应导致基于信号接收强度(RSSI)的室内定位方法精度不高,采用更细粒度的物理层信道状态信息(CSI)可以区分不同路径,提高定位精度。在已有基于CSI室内定位方法的基础上,通过改进对数距离路径损耗模型,得到CSI与传输距离的关系,并结合目标位置所测得的CSI值回归出目标与发射端的距离,最后通过三边定位法预测出目标的位置坐标。实验表明,相比基于RSSI的定位方法以及已有的基于CSI的定位方法,所提方法2 m以内的误差概率提高了将近40%和20%,有效提高了定位精度。  相似文献   
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为了解决航空发动机双通道电子控制器(EEC)两个通道均发生故障时如何评估通道健康度,从而选择主控通道的问题,论文提出了基于逆模型计算发动机推力敏感度的方法,量化不同信号故障对发动机推力的影响程度,依据推力敏感度来评估双通道健康度,协助主控通道选择,最终提高系统的安全性。  相似文献   
10.
基于玉米和大豆等粮食国际、国内价格历史数据,运用协整及误差修正模型、脉冲响应函数等方法,揭示国际粮价对国内粮价的传导作用及影响路径。理论分析表明,国际粮价通过进口直接路径、进口产品成本路径和进口替代路径等三个子路径传导至国内粮价。实证检验发现,国际大豆价格进口直接路径和进口产品成本路径传导均比较充分,即国际大豆价格会影响大豆进口价格,进而影响国内大豆价格,最终影响国内豆油价格;国际玉米价格进口直接路径和进口产品成本路径传导则不充分,国际玉米价格会影响玉米进口价格,但是对国内玉米价格和国内玉米淀粉价格影响程度较低;而在进口替代路径中,玉米和大豆的国际价格传导均不充分。我国应继续推进以提质增效为目标的农业供给侧结构性改革,加大粮食生产科技投入力度,调动农民种粮积极性,集中力量提高粮食供给质量和效率;坚持粮食进口仅为调剂国内供求余缺的方针,把握粮食安全的主动权;建立健全粮食市场的价格调控体系及风险防控体系,规避国际粮食市场剧烈波动对国内粮食市场的影响。  相似文献   
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