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991.
随着信息技术的发展,数字经济已经成为经济增长的新引擎。但由于缺乏权威的产业统计分类标准,学者们一直面临数字经济研究缺乏数字依据的尴尬境地。文章基于国家统计局公布并实施的《数字经济及其核心产业统计分类(2021)》中的分类标准,对各省份统计年鉴的数据进行重新整理,利用熵权法构建数字经济发展指数,测度了我国30个省份的数字经济发展水平,分析了各省份数字经济发展的差异以及时空特征。研究发现,2009—2019年我国数字经济产业发展迅猛,各项子产业都取得了长足的进步。相比较而言,数字要素驱动业发展速度略低于其他三个子产业;数字经济发展存在着明显的区域不平衡。东中部地区的数字经济发展状况明显优于西部地区,南方优于北方,而且区域不平衡有持续扩大趋势。  相似文献   
992.
根据国家档案局《全国档案信息化建设实施纲要》和《电子文件归档及电子档案管理规范》,以推动高校档案管理现代化、信息化和服务利用工作网络化为出发点,从档案信息化基础设施建设、档案信息资源建设、档案管理应用系统建设、保障措施等方面,探讨高校档案信息化模式构建。  相似文献   
993.
伍慧萍  姜域 《国际论坛》2015,(2):70-74,81
德国选择党这支疑欧势力在现有的政党谱系中无法对号入座,却在德国政坛迅速崛起。本文分析该党目前的发展现状,从政党纲领、组织结构和政治动员等多方面探讨其成功原因,进而从政党生命周期理论出发,揭示这一新兴政党所处发展阶段及其对现有政党体制、尤其是右翼阵营的冲击,并研判该党的发展前景与制约因素。  相似文献   
994.
A \(k\)-connected (resp. \(k\)-edge connected) dominating set \(D\) of a connected graph \(G\) is a subset of \(V(G)\) such that \(G[D]\) is \(k\)-connected (resp. \(k\)-edge connected) and each \(v\in V(G)\backslash D\) has at least one neighbor in \(D\). The \(k\) -connected domination number (resp. \(k\) -edge connected domination number) of a graph \(G\) is the minimum size of a \(k\)-connected (resp. \(k\)-edge connected) dominating set of \(G\), and denoted by \(\gamma _k(G)\) (resp. \(\gamma '_k(G)\)). In this paper, we investigate the relation of independence number and 2-connected (resp. 2-edge-connected) domination number, and prove that for a graph \(G\), if it is \(2\)-edge connected, then \(\gamma '_2(G)\le 4\alpha (G)-1\), and it is \(2\)-connected, then \(\gamma _2(G)\le 6\alpha (G)-3\), where \(\alpha (G)\) is the independent number of \(G\).  相似文献   
995.
The routing and wavelength assignment problem (RWA) has shown to be NP-hard if the wavelength continuity constraint and the objective of minimizing the number of wavelengths are considered. This paper introduces a multi-neighborhood based iterated tabu search algorithm (MN-ITS), which consists of three neighborhoods with a unified incremental evaluation method, to solve the min-RWA problem. The proposed MN-ITS algorithm is tested on a set of widely studied real world instances as well as a set of challenging random ones in the literature. Comparison with other reference algorithms shows that the MN-ITS algorithm is able to improve five best upper bounds obtained by other competitive reference algorithms in the literature. This paper also presents an analysis to show the significance of the unified incremental evaluation technique and the combination of multiple neighborhoods.  相似文献   
996.
Our main objective is to investigate the influence of the bargaining power within a chain on its industry. As a building block, we first discuss the implications of bargaining within a single chain by considering an asymmetric Nash bargaining over the wholesale price (BW). We show that both Manufacturer Stackelberg (MS) and vertical integration (VI) strategies are special cases of the BW contract. We then develop the Nash equilibrium in an industry with two supply chains that use BW. We identify the profit‐maximizing (coordinating) bargaining power within this industry. We show that when a chain is not monopolistic, VI does not coordinate the chain and that the MS contract, where the manufacturer has all the bargaining power, is coordinating when competition is intense. We find that the main determinant of the equilibrium in mature industries is to respond well to the actions of the competing chain rather than to directly maximize the profit of each chain. That is, the equilibrium does not necessarily maximize the profit of the entire industry. While a coordination of the industry could then increase the profitability of both chains, such a coordination is likely against antitrust law. Moreover, if one chain cannot change its actions, the other chain may unilaterally improve its profitability by deviating from the equilibrium. Our results lead to several predictions supported by empirical findings, such as that in competitive industries chains will work “close to” the MS contract.  相似文献   
997.
This article investigates a hybrid procurement mechanism that combines a reverse auction with flexible noncompetitive contracts. A buyer adopts such mechanism to procure multiple units of a product from a group of potential suppliers. Specifically, the buyer first offers contracts to some suppliers who, if accepting the contract, do not participate in the auction while committing to selling a unit to the buyer at the price of the subsequent auction. For the suppliers rejecting the offers, they can join the subsequent auction with the other suppliers to compete on the remaining units. When the buyer offers only one flexible noncompetitive contract, we find that the selected supplier may accept the offer regardless of whether he knows his exact cost information. Meanwhile, the buyer can benefit from offering such a contract, as opposed to solely conducting a regular reverse auction or offering a noncompetitive contract that does not allow suppliers declining offers to join the subsequent auction. Moreover, we find that the suppliers' information about their own costs has a significant impact on the buyer's decision. When the buyer makes multiple offers, we analyze the resulting game behavior of the selected suppliers and demonstrate that the buyer can benefit more than just offering one such contract. Therefore, the hybrid procurement mechanism can be mutually beneficial for both the buyer and the selected suppliers.  相似文献   
998.
吴建华等 《统计研究》2015,32(9):97-103
在宏观经济和金融资本市场上广泛存在着非线性时变参数时间序列,而当前的研究主要关注静态参数状态空间模型的估计。本文通过引入变点分析,改进了静态参数的粒子学习滤波技术,提出了变点粒子学习滤波技术,用于估计时变参数状态空间模型。并且利用模拟实验同经典的变结构IMM滤波技术进行了对比,结果显示,本文提出的变点粒子学习滤波在动态模拟样本数据方面具有更大的优势。可以用于对股票价格和成交量的联合动态轨迹进行实时的模拟追踪。  相似文献   
999.
Outliers are commonly observed in psychosocial research, generally resulting in biased estimates when comparing group differences using popular mean-based models such as the analysis of variance model. Rank-based methods such as the popular Mann–Whitney–Wilcoxon (MWW) rank sum test are more effective to address such outliers. However, available methods for inference are limited to cross-sectional data and cannot be applied to longitudinal studies under missing data. In this paper, we propose a generalized MWW test for comparing multiple groups with covariates within a longitudinal data setting, by utilizing the functional response models. Inference is based on a class of U-statistics-based weighted generalized estimating equations, providing consistent and asymptotically normal estimates not only under complete but missing data as well. The proposed approach is illustrated with both real and simulated study data.  相似文献   
1000.
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