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1.
This study draws on customer-dominant logic and self-expansion theory to examine the drivers of customer engagement behaviors in the context of emerging online interest communities. The engagement behaviors seen in online communities are operationalized into four types: augmenting, co-developing, influencing, and mobilizing. Goal pursuit (gratifying-the-self, enabling-the-self, and enriching-the-self) and emotional attachment to the community are found to be the key antecedent factors of these behaviors. The attainment of gratifying-the-self has a direct influence on these behaviors, whereas the attainment of enabling-the-self and enriching-the-self influences them via emotional attachment to the community.  相似文献   
2.
Inspired by some works of Kirkby, J. L. [2015. Efficient option pricing by frame duality with the fast Fourier transform. SIAM Journal on Financial Mathematics 6(1), 713–747; 2016. An efficient transform method for Asian option pricing. SIAM Journal on Financial Mathematics 7(1), 845–892], we present a systematic study on effectively computing the Gerber–Shiu function in the Lévy risk model, where the frame duality projection is used for approximation. By introducing an auxiliary function, we provide a smooth extension of the Gerber–Shiu function, which has closed-form Fourier transform and is differentiable over the whole real line under some conditions. The objective function is approximated by its frame duality projection onto a Riesz basis, and the projection coefficients are readily computed by the fast Fourier transform algorithm. Error analysis is made and the effectiveness of our results will be further illustrated in the numerical experiments.  相似文献   
3.
在广义空间调制(GSM)系统中,最大似然(ML)检测可以取得最优的检测性能,然而其计算复杂度随激活天线数的增加急剧增长。针对这一问题,提出了一种基于稀疏重构理论的低复杂度检测算法——正则化正交匹配追踪(ROMP)算法。该算法首先根据信道矩阵和当前残差的内积选取多个候选激活天线索引,接着对候选天线索引按正则化标准进行可靠性验证,剔除错误索引,缩小信号的搜索空间,最后通过求解最小二乘问题估计信号。仿真结果表明,与经典的正交匹配追踪(OMP)算法相比,所提算法以少许复杂度的增加为代价极大提升了检测性能,能够在检测性能与复杂度之间取得更好的折中。  相似文献   
4.
基于ANP-PP-SPA的区域洪灾风险评价模型研究   总被引:1,自引:0,他引:1  
针对现有洪灾风险评价模型的缺陷与不足,从致灾因子、孕灾因子、承灾因子和减灾因子4个方面,通过对14项评价指标的分析与计算,构建洪灾风险评价体系。洪灾风险评价体系以网络层次分析法(ANP)求解主观权重,投影寻踪法(PP)求解客观权重,主客观综合权重与集对分析理论(SPA)耦合,构建基于ANP-PP-SPA的洪灾风险评价模型。以广东省英德市为例,验证洪灾风险评价模型的适用性。计算结果表明,英德市2016年的洪灾风险属于中等级别,符合英德市2016年的实际情况。洪灾风险评价模型不仅综合考虑了评价指标间的相互关系,还较好地体现了洪灾风险的模糊性和随机性,能够为区域洪灾风险决策和洪水管理提供科学依据。  相似文献   
5.
In 2017, the Chinese government implemented a national strategy of "Rural Vitalization" that sought to realize full-scale rural vitalization. However, is it possible to achieve vitalization for all the villages in China? How should their development potential be determined? This paper identified and analyzed the "element-composite" messages of rural development based on 99 exemplary sites of “Beautiful Villages” in China. Combined with the projection pursuit classification method, a diagnostic system of rural vitalization was established; then, Dehua County was taken as a case study for an in-depth analysis. Based on national data analysis, the final results indicated that livelihood resources (LR), agglomeration effects (AE), location and transportation (LT), cultural/natural landscapes (CN), and economic circumstance (EC) are essential elements for successful rural development. Additionally, EC was the only exogenous element, while the remaining elements were endogenous. Furthermore, the villages with better EC presented urbanization rates of 38∼82 % and Engel coefficients of 29∼41 % in their counties; exemplary sites lacking LR, CN, LT, and AE account for 13.13 %, 19.19 %, 26.26 %, and 60.61 % respectively, so the indispensability of these elements decreases progressively in sequence. Only 2 % of villages rely on single element for success, therefore, the composite pattern of development element was also critical; 10 out of 16 types were found to successfully facilitate village development, among which, the type of R-a-L-C (32.32 %) and R-A-L-C (15.15 %) were considered as the greatest potential patterns for vitalization. Finally, by means of the diagnostic system, the ratio of representative villages for high-low potential in Dehua County is evenly split; then, development paths, and land use policies that match with paths were proposed, on the basis of development potential and “element-composite” condition of themselves.  相似文献   
6.
ABSTRACT

Based on role theory, the article examines the images that ASEAN member governments project of their organization. It rests on a discourse analysis of 198 speeches in the United Nations General Assembly between 1998 and 2017. Findings suggest that ASEAN does not figure as a top priority for delegates and that an overarching ASEAN role conception is missing. However, their addresses reveal parameters on which a collective role conception can be built. Individual ASEAN countries undertake great efforts to project themselves as ‘good global citizens,’ a role conception that could also be applied to ASEAN.  相似文献   
7.
为利用投影寻踪(PP)技术科学,客观评价区域水资源可持续发展能力,基于生态环境、水资源和经济社会因素选取20个指标构建区域水资源可持续发展能力评价指标体系。利用新型仿生群体智能算法——凉亭鸟优化(SBO)算法优化PP技术最佳投影方向,提出SBO-PP水资源可持续发展能力评价模型,并构建灰狼优化(GWO)算法-PP模型、人工蜂群(ABC)算法-PP模型、差分进化(DE)算法-PP模型、地理生物学优化(BBO)算法-PP模型、粒子群优化(PSO)算法-PP模型作对比,以云南省2006—2015年及2020年水资源可持续发展能力评价为例进行实例研究。结果表明:SBO算法优化PP技术获得的适应度值优于GWO、ABC、DE、BBO和PSO算法,具有较好的求解精度、稳健性能和极值寻优能力。SBO-PP模型对云南省2006—2007年水资源可持续发展能力评价为"较差",2008—2015年评价为"中等",2020年评价为"较强"。  相似文献   
8.
[目的]农民用水合作组织是我国灌溉管理制度改革的产物,农民用水合作组织的建立改进了农村水利管理的方式,提高了灌溉管理过程中水资源的利用率。[方法]通过构建粮食主产区农民用水合作组织绩效评价指标体系,建立基于实数编码加速遗传算法的投影寻踪分类模型,对湖北、湖南、黑龙江等3省61家农民用水合作组织的绩效进行了实证分析。[结果]粮食主产区农民用水合作组织绩效水平总体较好,在所调查的61家农民用水合作组织中,27.1%的农民用水合作组织绩效为优秀,28.8%绩效良好,13.6%绩效一般,30.5%绩效较差。[结论]总体上来看,湖南、湖北等2省农民用水合作组织的绩效高于黑龙江。是否有产权、农户参与率、是否民主决策、培训次数、农户满意度、单位面积灌水量和水费收取率等指标对农民用水合作组织绩效影响最大。因此,政府适当放权,选取恰当的扶持方式,提升农户的认识,推广好的农民用水合作组织发展模式是提高农民用水合作组织绩效的有效途径。  相似文献   
9.
吴丹  胡晶 《工业技术经济》2017,36(5):140-146
科技创新、经济发展与生态环境建设作为国家治理体系的重要组成部分,对于我国国民经济和社会发展具有明显的推动作用。本文参考现有文献中科技创新、经济发展与生态环境建设3个维度的相关指标,构建科技-经济-生态系统协调度评价指标体系。并采用灰关联分析法、投影寻踪法和协调度模型,综合评价我国不同时期的科技-经济-生态系统的综合发展水平及其协调度。研究结果表明,2000~2015年,我国科技-经济-生态系统的综合发展水平处于快速增长阶段,年均增长率为6.22%,其中,科技创新水平、经济发展水平、生态环境建设水平的年均增长率分别为5.95%、5.35%、6.43%。同时,我国科技-经济-生态系统的协调度达到0.992。其中,“十五”~“十二五”时期,我国科技-经济-生态系统的协调度持续提升,分别达到0.8465、0.8466、0.9152。总体来看,在经济发展新常态下,我国政府通过加快转变经济发展方式和社会发展方式,同步提高科技创新水平、经济发展水平、生态环境建设水平,有利于进一步提升科技-经济-生态系统的综合发展水平及其协调度。  相似文献   
10.
Varying coefficient regression models are known to be very useful tools for analysing the relation between a response and a group of covariates. Their structure and interpretability are similar to those for the traditional linear regression model, but they are more flexible because of the infinite dimensionality of the corresponding parameter spaces. The aims of this paper are to give an overview on the existing methodological and theoretical developments for varying coefficient models and to discuss their extensions with some new developments. The new developments enable us to use different amount of smoothing for estimating different component functions in the models. They are for a flexible form of varying coefficient models that requires smoothing across different covariates' spaces and are based on the smooth backfitting technique that is admitted as a powerful technique for fitting structural regression models and is also known to free us from the curse of dimensionality.  相似文献   
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