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为了同时对多个异构信道进行有效地合作频谱感知,并克服现有方法中只考虑检测准确性而忽略感知开销和系统效益,忽略不同认知用户对不同异构信道感知性能的差异以及参与合作感知的认知用户较多等问题,提出了一种贪婪的异构多信道并行合作频谱感知方法。根据对感知开销和传输收益的定义,充分考虑不同认知用户对不同异构信道感知性能的差异,利用贪婪算法在多个认知用户和多个异构信道间最优地进行感知任务分配,使总系统效益最大。仿真结果表明,所提方法与基于迭代匈牙利的并行合作频谱感知方法、改进的基于迭代匈牙利的并行合作频谱感知方法和随机的合作频谱感知方法相比,能够获得较高的总系统效益,且所需的参加合作感知的认知用户数较少。 相似文献
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频谱感知是认知无线电网络的一项关键技术。低信噪比(SNR)环境下频谱检测的性能会大
幅降低,而随机共振(SR)能
有效提高信号信噪比,所以将其应用到频谱感知中,能增强认知用户对主用户(PU)的检测
性能。〖JP2〗首先介绍了随机共振在认知无线电频谱感知中应用的最新研究进展,包括随
机共振在
本地感知中(如能量检测、协方差矩阵频谱感知、循环平稳特征检测)及协作感知中的应用
,然后指出了随机共振在认知无线电频谱感知中还有待解决的问题,并提出了下一步的研究
方向。 相似文献
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在分布式认知无线网络场景下,针对传统协作压缩频谱估计收敛速度慢、计算复杂
度高的问题,提出了一种差分协作压缩频谱估计算法用于宽带频谱感知。算法通过利用不同
认知用户感知的宽带信号所满足的相同频谱支撑集特征,实现了在邻居节点感知先验信息条
件下,本地认知用户基于压缩测量向量差值的宽带频谱迭代估计。仿真分析结果表明,所提
算法在频谱估计精度、检测性能与计算复杂度方面均获得了明显改善。 相似文献
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频谱感知是通信系统抗干扰和智能化的关键能力。针对认知无线电系统窄带频谱感知技术受制于数模转换器件的发展水平,难以解决认知无线电系统宽带、实时频谱感知的问题,提出一种多节点协作的认知无线电系统宽带频谱感知方法。该方法设计由多个认知节点对目标频段执行次奈奎斯特采样来降低采样速率,采用能量检测方式对采样矢量进行集中式融合判决,实现宽频段范围内干扰信号的谱定位和判断,降低各个感知节点的采样速率,支撑认知网络系统构建高实时、宽频带频谱感知的能力。计算机仿真试验结果表明,所提方法达到90%检测概率时压缩比要求为0.025,具有可靠性与有效性。 相似文献
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In this study, we evaluate how the effect of customers' experiences on revisit intention for non-indigenous restaurants can be moderated by economic distance (ED), cultural distance (CD) and global-connectedness distance (GD) between the country of origin for a given non-indigenous restaurant and the customer’s resident country. Surveys were conducted in seven countries across three continents, and the levels of ED, CD and GD between Korea and the seven countries were used as moderators. The findings suggest that the types of food and staff are two elements that should be emphasized in countries that are relatively close to Korea. Conversely, elements like the atmosphere of the restaurant and word of mouth should be emphasized in countries that have greater distances from Korea. Of the three distances considered in the study, GD had the strongest moderating effect on the relationship between customers’ experiences and their intentions to return to the restaurant. As a whole, the results imply that ED, CD and GD are important points of reference when considering prior experience while selecting a target country based on the strength of the restaurant’s experience management. 相似文献
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美国国际贸易法院判定美国商务部对河北兴茂轮胎有限公司非公路用轮胎“双反”措施不当案评述 总被引:1,自引:0,他引:1
美国进口商和中国出口商不满美国商务部对来自中国的某些非公路用轮胎实施反倾销和反补贴税的裁定,向美国国际贸易法院提出起诉。美国国际贸易法院裁定,美国法律没有明确规定反倾销税法是否可适用于非市场经济国家;本案中美国商务部做的"双反"裁定,在方法上不合理。本文在介绍该案的基本案情、归纳法院推理和判决的基础上,对该案涉及的法律问题做了简要评论。 相似文献
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Unlike previous studies which only focus on the main effect between IC and FV, this research includes PTE with the gap of resource-based view. IC is a key element in creating a competitive advantage, as it has a great influence on FV. A company may put relatively less into IC if it demonstrates higher efficiency. However, previous studies have neglected the fact that relative efficiency and IC affect FV and stock returns directly and indirectly. The research period was from 2006 to 2010 and the main research methods include HRA and DEA. The main research findings include the following. (1) There is a space for improvement in terms of the total technical efficiency. (2) PTE has a significant moderating effect between IC and FV. (3) IC and PTE have a significant influence on FV. (4) Apart from PTE and stock returns, IC and FV show significant differences within the sub-industry. 相似文献
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文章根据风险调整收益(RAROC)的原理,借鉴J.P.摩根的信用计量CreditMetrics模型中信用等级转移的思想,构建了应收账款回收期内受信企业信用状况转移矩阵,并据此计算出企业信用VaR值和经济资本CaR值,进而计算RAROC比值,可为企业信用销售决策提供依据。通过将RAROC方法引入企业信用风险管理体系,可以对企业经营活动进行基于风险的绩效考核和业绩评价,以期提高企业信用风险管理水平。 相似文献
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Miguel D Ramirez 《The journal of international trade & economic development》2013,22(2):159-178
This paper addresses the important question of whether public investment spending on economic infrastructure enhances economic growth in Mexico. It estimates a Cobb-Douglas production function that includes public infrastructure capital. Using cointegration analysis, the paper estimates a vector error correction model (VECM) for the 1995?–?99 period. The results suggest that there is a long-term stable relationship among the variables included in the VECM. The evidence also indicates that both public infrastructure spending and private capital formation have a positive and highly significant effect on the rate of output growth. Finally, the impulse response functions (IRF) and the variance decompositions (VDC) of the endogenous variables in the VECM suggest that the response of private capital to public infrastructure is positive while the reverse causation is not affirmed. From a policy standpoint, the findings call into question stabilization policies that disproportionately reduce public infrastructure to meet targeted reductions in the fiscal deficit (JEL, O1, O47, O54). 相似文献
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采用高效液相色谱(HPLC)与电感耦合等离子体质谱(ICP-MS)联用技术,建立了粉质化妆品中六价铬的测定方法。样品经0.05 mol/L氢氧化纳溶液超声振荡提取;HPLC采用Hypersil GOLD C18柱分离,以5%(v/v)甲醇-2 mmol/L四丁基硫酸氢铵水溶液(pH 4.0)作为流动相;ICP-MS测定选用碰撞池技术以消除40Ar12C对52Cr的谱学干扰。方法学研究结果表明,添加水平为0.040-2.000 mg/kg时,回收率为77.5%-107.5%,相对标准偏差(RSD)小于10%。 相似文献
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《International Business Review》2023,32(3):102066
In recent years, there has been an exponential increase in the amount of foreign investment by emerging market multinational enterprises (EMNEs). While it has been debated whether EMNEs strengthen or weaken the institutions in host countries they invest in, the literature has paid limited attention to how EMNE investment impacts corruption in other emerging markets, one of the most significant destinations of EMNEs. Following Hoskisson et al. (2013), we categorize two types of emerging markets as targets of EMNE investment, a) low-income emerging markets and b) middle-income emerging markets, based on their institutional and market development. Building on the theory of firm-specific advantages (FSAs) and the institutional advantage (IA) of EMNEs, we reason that EMNEs enter foreign markets in accordance to where their skills and competencies can be effectively utilized, and this impacts corruption in the host country. We make two key arguments: (1) EMNEs predominantly use their IA in low-income emerging markets, which in the long term increases corruption in the host market, and (2) EMNEs predominantly use their FSAs to gain competitive advantage in middle-income emerging markets, which decreases corruption in the host market. Empirical analysis of Chinese outward FDI from the 2008-2018 period supports our hypotheses. Our research contributes to both the literature on EMNEs and corruption. 相似文献
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供应链管理和虚拟企业是已经在世界范围所采用的概念。这些概念包括一系列管理、组织和技术问题,公司为了提高竞争能力,开拓市场机遇,建立合作联盟。供应链管理是一种集成的管理思想,从战略上整体地整合供应商和顾客。虚拟企业是一种动态的临时组织形式,不同的企业为了开拓商业机遇而通过合作弥补自身竞争力的不足。虽然他们有各自的特点,但是也有共同点。 相似文献
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Kim Nguyen Thuy Hang Dao 《Journal of Promotion Management》2018,24(3):398-419
ABSTRACTBuilding on social-identity theory, the research develops a model for understanding of the impact of consumer identification with a nation on consumers' brand evaluations. It posits that developing-country consumers' identification with a foreign (developed) nation influences three factors—consumer-based brand equity, consumer-based country image, and consumer-based brand credibility. The research was informed by data from 400 Vietnamese consumers in relation to two Japanese brands Sony and Honda and analyzed using structural equation modeling (SEM). The findings show that Vietnamese (developing-country) consumers prefer Japanese (developed-country) brands over domestic brands, when these consumers identify with the developed nation. 相似文献
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Customers voice their negative brand experiences to their family and friends in the form of negative word-of-mouth (NWOM). Web 2.0 enables the sharing of NWOM in electronic format on various social media sites, online customer review forums, and blogs, which is known as negative electronic word-of-mouth (NeWOM). Researchers need to study the spread of NWOM/NeWOM to prevent adverse consequences for companies and suggest an optimal response for its redressal. Existing literature review studies have focused on word-of-mouth (WOM) and electronic WOM (eWOM) and have considered both positive and negative WOM and eWOM concurrently. Past literature reviews have captured the breadth of the WOM domain, ignoring the depth. This research article contains a review of 282 journal papers capturing the depth of the extant literature by focusing solely on ‘negative’ WOM and eWOM (NWOM and NeWOM), and presents a broad view of the NWOM and NeWOM domains using morphological analysis (MA). This will help to conceptualize and categorize the existing state-of-the-art literature into broad dimensions and identify future research opportunities. The MA framework helps to bifurcate this literature into the following four dimensions: (i) nomenclature of NWOM and NeWOM, (ii) antecedents of NWOM/NeWOM, (iii) impacts of NWOM/NeWOM, and (iv) prevention and recovery response to NeWOM. Further dissection of these four dimensions leads to 15 sub-dimensions and 217 variants. Combinations of the 217 variants enable the identification of 550 novel future research opportunities in the area of NWOM and NeWOM. 相似文献