一种基于RAMP算法的OFDM稀疏信道估计方法

针对OFDM稀疏信道估计需要信道稀疏度作先验条件的不足,将正则化自适应匹配追踪（RAMP ） 用于信道重建,可在信道稀疏度未知的情况下,自适应地调整候选集原子的个数,并利用正 则化过程实现支撑集的二次筛选,逐步扩大支撑集,准确地估计出信道的冲激响应。仿真结 果表明,该方法收敛速度快,估计效果好,有较好的应用价值。     

基于DSP和FPGA的嵌入式数字直接序列扩频系统的研制

介绍了一种基于Xilinx公司的FGA(Spartan2 XC2S200)和TI公司的DSP TMS320VC5410设计的直接序列扩频收发机，其下变频后的部分，如PN码的捕获、跟踪、基带解调(去掉剩余频差)等全部采用FPGA数字实现。对PN码的捕获，采取了一种门限自适应控制的双积分滑动相关捕获方法，既大大节省了FPGA的硬件设计资源，又能使PN码的平均捕获时间足够小。经实验测试，该系统各参数完全达到设计要求。     

一种适用于稀疏多径信道的自适应均衡算法

针对传统的自适应均衡算法在稀疏多径信道下性能表现不佳的问题,提出了一种基于基追踪降噪的自适应均衡算法。该算法利用稀疏多径信道下均衡器权值的稀疏性,将自适应均衡器的训练过程看作压缩感知理论中稀疏信号对字典的加权求和,并利用重构算法直接对稀疏权值进行求解,解决了迭代参数设置和收敛慢的问题。采用基追踪降噪作为重构算法并选用变量分离近似稀疏重构对该最优化问题进行求解,既提高了权值的重构精度又降低了计算的复杂度。仿真结果表明,所提算法能够以较低的计算量和较少的训练序列达到更优性能,这对提升系统的通信性能具有参考价值。     

放大器估计器的查表法自适应预失真器设计

非线性功放特性随温度,供电电压等因素的变化而改变,为保证其稳定工作,预失 真系统的自适应性能就显得非常重要。当前的自适应预失真算法每次都对其参数进行更新, 计算量很大。针对这个问题提出了一种放大估计器的查表法自适应预失真算法,将查表法和 放大器估计器法结合在一起,以误码率为指标在系统允许的误差范围内可以大大减少参数的 迭代次数。同时针对不同的输入回退,可以选择采用不同的预失真算法,从而使其更加接近 功放特性,进一步减少迭代次数。     

Why Agents for Automated Negotiations Should Be Adaptive

We show that adaptive agents on the Internet can learn to exploit bidding agents who use a (limited) number of fixed strategies. These learning agents can be generated by adapting a special kind of finite automata with evolutionary algorithms (EAs). Our approach is especially powerful if the adaptive agent participates in frequently occurring micro-transactions, where there is sufficient opportunity for the agent to learn online from past negotiations. More in general, results presented in this paper provide a solid basis for the further development of adaptive agents for Internet applications.     

基于帧间相关性的自适应采样率分块视频压缩感知

针对现有基于自适应采样率的分块视频压缩感知方案的单帧总采样率不可控的问题,提出了一种新的自适应采样率分配方案。首先,对当前帧图像块进行固定预采样;然后,根据预采样的测量值来估计图像块的变化程度,并计算该图像块与当前帧图像的复杂度比例;接下来,根据复杂度比例分配图像块自适应采样率,并将固定预采样及自适应采样的测量值合并为最终测量值。实验结果表明,与固定采样率算法相比,提出的方案在相同采样率下可获得1 dB左右的峰值信噪比增益。所提方案可获得高质量的重构图像,且总采样率可控,因此增强了自适应采样分块视频压缩感知方案的有效性和实用性。     

Reverse stress testing: Scenario design for macroprudential stress tests

We propose a systematic algorithmic reverse-stress testing methodology to create “worst case” scenarios for regulatory stress tests by accounting for losses that arise from distressed portfolio liquidations. First, we derive the optimal bank response for any given shock. Then, we introduce an algorithm which systematically generates scenarios that exploit the key vulnerabilities in banks' portfolio holdings and thus maximize contagion despite banks' optimal response to the shock. We apply our methodology to data of the 2016 European Banking Authority (EBA) stress test, and design worst case scenarios for the portfolio holdings of European banks at the time. Using spectral clustering techniques, we group 10,000 worst-case scenarios into twelve geographically concentrated families. Our results show that even though there is a wide range of different scenarios within these 12 families, each cluster tends to affect the same banks. An “Anna Karenina” principle of stress testing emerges: Not all stressful scenarios are alike, but every stressful scenario stresses the same banks. These findings suggest that the precise specification of a scenario is not of primal importance as long as the most vulnerable banks are targeted and sufficiently stressed. Finally, our methodology can be used to uncover the weakest links in the financial system and thereby focus supervisory attention on these, thus building a bridge between macroprudential and microprudential stress tests.     

TD-SCDMA系统中智能天线的重复迭代自适应算法

提出一种用于TD-SCDMA系统的重复迭代自适应智能天线算法。通过在自适应算法中把阵列输入信号和作为参考信号的训练序列重复使用,可以在短训练序列情况下实现较好的收敛,提高通信系统的传输效率。对LMS算法中全训练序列重复迭代和滑动窗口重复迭代算法进行了仿真,结果表明,在有限训练序列时本算法比传统LMS算法更好地逼近最佳解。     

Leadership for Sustainability: An Evolution of Leadership Ability

This article examines the existing confusion over the multiple leadership styles related to successful implementation of corporate social responsibility/sustainability in organisations. The researchers find that the problem is the complex nature of sustainability itself. We posit that organisations are complex adaptive systems operating within wider complex adaptive systems, making the problem of interpreting just in what way an organisation is to be sustainable, an extraordinary demand on leaders. Hence, leadership for sustainability requires leaders of extraordinary abilities. These are leaders who can read and predict through complexity, think through complex problems, engage groups in dynamic adaptive organisational change and have the emotional intelligence to adaptively engage with their own emotions associated with complex problem solving. Leaders and leadership is a key interpreter of how sustainability of the organisation ‘links’ to the wider systems in which the organisation sits, and executing that link well requires unusual leaders and leadership systems.     

Necessary but not sufficient: Beyond novelty in advertising creativity

Novelty has been considered the bedrock of creative advertising. However, Ang, Lee, and Leong (2007, Journal of the Academy of Marketing Science 35: 220–232) proposed in their ad creativity cube that, to be effective, novel ads need to be both meaningful and connect to their audience as well. This study empirically tests whether the effects of novelty can be enhanced by meaningfulness and connectedness. Results generally showed that novelty, coupled with meaningfulness and connectedness, enhances consumer ad response. Such ads were evaluated as being more creative and were recalled and liked better than novel ads which lack either meaningfulness or connectedness, or both, as well as less novel ads of a similar nature. Implications are discussed and directions for future research suggested.     

Service provider responses to anxious and angry customers: different challenges, different payoffs

Anxiety and anger, two frequently experienced emotions during service consumption, arise from different appraisals of the eliciting event, i.e., attribution to uncontrollable circumstances and low coping potential for anxiety versus attribution to providers and high coping potential for anger. These appraisal differences were hypothesized to impact the occurrence of supportive provider responses (higher for anxiety than for anger), and the value given to supportive responses by anxious versus angry customers (higher evaluation for anxiety than for anger). It was also hypothesized that, although evaluation of provider response would mediate the relationship between the intensity of both anger and anxiety and satisfaction with the service encounter as a whole, the power of this mediating effect would be stronger for anxiety than for anger. Hypotheses were confirmed in a survey of air travel passengers reporting episodes of anxiety and anger. Implications of these results for challenges and payoffs involved in the development of adaptive response strategies to anxious and angry customers are discussed.     

Not all adaptive selling to omni-consumers is influential: The moderating effect of product type

Computer-mediated technologies have resulted in a proliferation of the omni-channel consumer (OCC) who shops for products and services using mobile, online, and traditional retail channels. While OCCs may have greater access to information, they do not necessarily have access to accurate information; hence the salesperson has both a challenge as well as an opportunity to use adaptive selling techniques when selling to the OCC. To better understand under what circumstances the salesperson can best be utilized to bring about the sale with the OCC, this research develops and evaluates a model of adaptive selling behaviors when selling to omni-channel consumers around the globe. Adaptive selling behaviors are conceptualized as having two dimensions, non-interactive and interactive adaptation. The efficacy of these two types of adaptive selling behaviors depends upon product type (utilitarian, hedonic) and OCCs' perceived control over the buying situation. To test the hypotheses, survey data was collected from global OCCs in four different countries and evaluated using path analysis. Results suggest salesperson’s influence depends upon product type and salesperson's adaptive selling behavior.     

基于公平性的多用户OFDM系统自适应功率分配松弛算法

近期我国ETF市场出现了大规模异常赎回而导致资产规模大幅下降的异常现象。本文对这一异常现象分析后发现其主要原因可能是:(1)我国市场为弱式有效市场,被动式投资业绩不如主动式投资;(2)成份股经常出现涨停而导致投资者难以购买到涨停股份,制约了ETF的申购规模;(3)我国投资者不愿长期持有ETF,而只是把ETF当作波段操作工具。ETF资产规模大幅下降归根结底是由于投资者对ETF产品没有信心,也就是投资者对上市公司存有很大疑义,对股市缺乏信心。     

用Laguerre滤波器实现多径衰落信道自适应均衡

提出了一种衰落信道自适应均衡的新方法。该方法基于Laguerre滤波器结构，采用最小二乘估计估算滤波器极点，通过RLS算法实现自适应过程。仿真结果表明，由于Laguerre滤波器同时具有FIR和ⅡR结构的特点，在信噪比低、信道多径条件复杂的情况下，可以获得比通常的线性自适应均衡器和决策反馈均衡器更好的抗符号间干扰的效果；同时，Laguerre滤波器结构的稳定性有效地减少了差错传播的发生。     

自适应扩散算法的误差性能分析

为了分析分布式协作频谱感知认知网络中融合矩阵、步长等参数对自适应扩散算法的影响,对检测量估计误差性能进行了研究。给出了自适应扩散算法检测量的通用迭代公式,分析了检测算法的数据处理流程;推导了检测量估计误差向量的迭代表达式,利用网络瞬时均方偏差性能和各节点的稳态均方偏差性能评价融合矩阵参数对算法的影响。结果表明,不同的融合矩阵选取原则影响算法的检测性能,可以采用检测量误差估计的方法对算法参数进行研究。     

Under the sway of a mobile device during an in‐store shopping experience

Mobile device technology is transforming the retail shopping experience. Today's consumers are mobile dependent, preferring to consult with their phone, instead of using the salesperson, while shopping at the retail store. In the absence of literature investigating how the salesperson might sell to this omni‐channel, mobile‐connected consumer, this paper proposes a conceptual model and tests its proposed linkages. The empirically tested model presents a dyadic view of the omni‐channel consumer and the salesperson. Uniquely contributing to the omni‐channel and marketing literature, samples from an emerging economy (India) and developed (United States) economy represent the contexts. Specifically, the research examines the salesperson's role in selling to a mobile‐dependent consumer who uses mobile technology to search for information during the sales meeting. Findings show that adaptive selling can affect purchase intention and customer predisposition to comply with salesperson input. Results also reveal how perceived control, mobile dependence, and customer predisposition to comply with mobile device input affect purchase intention. Managerial and research implications specifically appropriate for the omni‐consumer retail setting are offered.     

Synergistic,Antagonistic, and Asymmetric Media Interactions

Despite the highly touted potential for synergies in cross-media advertising, much has yet to be discovered about how the effects of multiple media combine to shape sales response. Two challenges related to the investigation of media interaction effects are their complex nature and their specification in a sales response model. The authors adopt a flexible modeling approach, multivariate adaptive regression splines (MARS), which captures parsimoniously complex interaction effects and facilitates their measurement and interpretation. Analysis of multiple data sets on brand sales and media spending points to the following typology of media interaction effects: (1) synergistic (positive interactions), (2) antagonistic (negative interactions), and (3) asymmetric, where each medium does not contribute equally to the interaction. The findings show that 44% of media spend produces synergistic effects, whereas 21% produces antagonistic effects. Hence synergy is not the de facto outcome of cross-media advertising. Interestingly, low-budget media play a key role in producing interaction effects.     

基于噪声分布特性的脉冲信号自适应门限检测

通过分析数字脉冲信号幅度差分的概率分布模型，得到噪声的分布特性，并推导出用于脉冲信号检测的时域自适应门限。该门限可通过计算信号幅度差分绝对值的均值直接得到。该门限算法的第一个优点是门限值仅与噪声统计特性相关，与信号无关，可避免传统自适应算法中检测门限被强信号拉高，造成强信号附近的弱信号漏检问题;第二个优点是计算复杂度低，非常适合于实时性要求高而资源不足的现场可编程逻辑门阵列（FPGA）等硬件平台实现，为脉冲信号的实时捕获和后续的侦察处理提供支撑。     

区域金融集聚与区域经济增长

协同性分析发现区域金融集聚与区域经济增长之间存在协同发展的趋势。平稳性检验与协整分析发现区域金融集聚与区域经济增长之间存在长期稳定的均衡关系。基于VAR模型的脉冲响应函数分析表明正向的区域金融集聚或区域经济增长冲击最终都将带来相互的正向响应。Granger因果关系检验进一步检验了不同滞后期区域金融集聚与区域经济增长之间的因果关系,发现区域金融集聚与区域经济增长之间存在互为因果的关系。区域金融、经济发展与宏观经济运行均需注重区域金融集聚与区域经济增长之间的协同效应。     

How ethical and political identifications drive adaptive behavior in the digital piracy context

Today, digital piracy remains a growing challenge for both legislators and businesses operating in the entertainment industry. This study explores when and why consumers make trade-offs between illegal and legal streaming services. By drawing on protection motivation theory, we find that consumers' threat and coping appraisals increase their adaptive behavior, i.e., lower intention to consume illegal and higher intention to consume legal streaming services. We also show that the strength of consumers' inherent ethical (relativism) and political (economic liberalism) identities conditions adaptive behavior through social identity theory. We find that low relativism strengthens the adaptive behavior through threat appraisal, while economic liberalism strengthens the adaptive behavior through coping appraisal. Our robustness checks show that these results hold when the model accounts for the level of consumers' digital piracy attitudes. We used a scenario-based approach to test our hypotheses and surveyed 244 consumers who use streaming services. Our study contributes to the literature by showing that consumers' adaptive behavior envisioned through protection motivation theory can be weakened or strengthened by their ethical and political identities.