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71.
基于多源数据的自然生态空间分类体系构建及其识别   总被引:2,自引:0,他引:2  
研究目的:探讨市县尺度下自然生态空间分类体系和多源数据下自然生态空间识别方法。研究方法:采用归纳比较法构建自然生态空间分类体系,通过综合分析法建立多分类体系转换机制,运用GIS空间分析法识别自然生态空间。研究结果:(1)市县级自然生态空间是指生产性空间和承载性空间以外,以发挥土地生态系统服务功能为主导,以提供生态产品为主,对维护区域生态系统稳定性,保障区域生态安全格局具有重要作用的用地空间;(2)自然生态空间可分为基础生态空间和人工生态空间两个一级类,10个二级类,26个三级类;(3)2015年鹤壁市自然生态空间总量606.08 km~2,其中基础生态空间554.41 km~2,人工生态空间51.67 km~2。研究结论:依据市县尺度自然生态空间分类体系,运用多源数据融合转换识别方法能快速准确识别自然生态空间数量和空间分布。  相似文献   
72.
[目的]目前我国正处于关键的经济转型期,生态农业和生态旅游业作为生态文明建设的重要产业之一,其耦合发展对于存进产业结构优化升级具有重要作用。[方法]通过构建生态农业与生态旅游业指标体系,采用灰色关联法计算江苏省生态农业与生态旅游业的关联度,进一步通过耦合协调度模型分析两者的协调程度。[结果]生态农业系统与生态旅游系统中的旅游经济、旅游资源和旅游价值的关联度分别为0.719,0.673和0.621,大小顺序分别为旅游经济旅游资源旅游价值,而生态旅游系统与生态农业系统中生态系统、经济系统和社会系统的关联度分别为0.687,0.700和0.626,大小顺序分别为经济系统生态系统社会系统,耦合作用均分别为较强、较强和中等。2012~2016年江苏省生态农业和生态旅游业耦合度处于磨合阶段,但一直在增加,同时耦合水平经历了初级协调发展水平到中级协调发展水平的过程。[结论]江苏省生态农业和生态旅游业的耦合发展仍有进步的空间,今后应加强耦合发展机制,推动两大耦合产业走向更深更广的发展领域,促进生态文明建设,同时保证生态产业的可持续健康发展。  相似文献   
73.
为了解决钢铁行业普遍亏损、经营困难等问题,对当前钢铁行业成本核算面临的各种问题进行分析,相应的提出新制度实施的必要性。而后详细阐述了钢铁行业成本核算制度的基本步骤,且针对行业现有问题说明了新制度的优越性,提出可以选择性使用的作业成本法,最后阐释了新制度可能会对钢铁行业产生的影响和企业在面对新制度想要改善目前严峻形势必须用辩证的眼光看待这一现象,具体问题具体分析,对症下药才是关键。  相似文献   
74.
Research in economic geography has paid increasing attention to regional innovation systems (RISs) as a potential vehicle for growth and development. Yet despite an increasing amount of research studying RISs in particular and economic regions in general, we have limited knowledge about their influence on entrepreneurs and entrepreneurship. We respond to this knowledge gap and study if entrepreneurs’ localization in thick vs. thin RISs affects their innovativeness and growth ambitions. Thick RISs are predominately urbanized spaces that include organizations of higher-level education, R&D intensive milieus, and an ample industry sector, while thin RISs to a lesser degree encompass these features. Empirically, we analyse 870–917 entrepreneurial firms in Agder of Southern Norway. Based on trade and labour markets, as defined by the EU’s classification of local administrative units (LAU1), we identify two thick and six thin RISs in Agder. Econometric analyses show that entrepreneurs located in thick RISs are more innovative than entrepreneurs located in thin RISs, but there are no significant differences concerning entrepreneurs’ growth ambitions. In light of our findings, we discuss the potential agency role played by entrepreneurial firms at a micro level on path dependent features of RISs at a macro level.  相似文献   
75.
旅游的产业属性决定了旅游地理研究的实践性,在服务国家战略和产业实践需求的过程中,中国旅游地理学科呈现出研究领域、方法和应用的新特征。本文围绕旅游规划、旅游资源、旅游大数据和旅游实验方法等进行总结与展望,认为:(1)旅游规划是透视旅游地理研究发展的重要视角,旅游规划的知识域主要包括旅游开发战略与对策、旅游业与旅游企业、乡村旅游与乡村振兴等12个方面;(2)新时代文化和旅游资源普查面临文旅资源保护和整合利用的重大现实需求,为旅游地理研究带来了文旅资源的内涵与分类评价、普查信息集成与应用、普查技术与组织方式等新命题;(3)大数据背景下要求旅游地理探寻新科学问题,重点要关注大数据旅游统计测量模型和指标规则的规范,数据伦理与信息茧房,大数据旅游现象的地理效应和相关空间格局等研究;(4)实验研究方法在认识论层面从描述走向解释预测,在方法论层面从调查走向直接测量,为认识和理解旅游情境下人地关系的核心科学问题提供了“科学化”的研究路径。因此,面对新时代战略要求和旅游业发展趋势,旅游地理学应加强产业实践、研究方法和学科交叉研究,提升学科服务国家战略和社会经济发展的支撑能力。  相似文献   
76.
We investigate the effects of the 2008 New Zealand (NZ)–China free trade agreement (FTA) on exports from NZ to China, and real GDP per capita in NZ using the synthetic control method to estimate the counterfactuals. NZ exports to China were more than 200% higher in 2014 than what they would have had the FTA never been signed. NZ's food and live animals exports to China were more than 180% higher in 2014 than the counterfactual. Our counterfactuals indicate a small but negative effect of the FTA on NZ's real GDP per capita between 2009 and 2012.  相似文献   
77.
In this article we introduce a linear–quadratic volatility model with co-jumps and show how to calibrate this model to a rich dataset. We apply GMM and more specifically match the moments of realized power and multi-power variations, which are obtained from high-frequency stock market data. Our model incorporates two salient features: the setting of simultaneous jumps in both return process and volatility process and the superposition structure of a continuous linear–quadratic volatility process and a Lévy-driven Ornstein–Uhlenbeck process. We compare the quality of fit for several models, and show that our model outperforms the conventional jump diffusion or Bates model. Besides that, we find evidence that the jump sizes are not normally distributed and that our model performs best when the distribution of jump-sizes is only specified through certain (co-) moment conditions. Monte Carlo experiments are employed to confirm this.  相似文献   
78.
The global hospitality industry has experienced significant consolidation in the past several decades. While evidence in the general business literature suggests that the target firm shareholders gain instead of the acquiring firm shareholders, some studies in the hospitality industry have suggested that mergers and acquisitions (M&As) are also beneficial to acquiring firms. Using a comparative study design and a comprehensive sample over 41 years, we empirically examine whether M&As create more value in the hospitality industry than in other industries and whether certain deal characteristics may explain the potential performance differential. Overall, we find that M&As in the hospitality industry outperform M&As in non-hospitality sectors. When examining deal attributes, we find that relative size of target, cash method of payment, and an unlisted target are characteristics positively related to merger performance and help explain some of the performance differential. We contribute theoretically and empirically to the literature by demonstrating that industry and deal effects play an important role in M&A performance.  相似文献   
79.
In this paper, we study the cryptocurrency pricing factors. We review the literatures which state that the cryptocurrency market is weakly efficient. We use the Fama–MacBeth method to investigate the pricing factors. The classical equity-based risk factors including size, momentum, and value to growth from the Fama–French three factor model are studied. We use crypto-unique coin-to-token as a proxy for value-to-growth. For volatility risk factor category, we investigate realized volatility, skewness and jump. We also investigate liquidity factors including bid–ask, volume growth and Roll’s measure. The macro factors are found not to be an explanatory factor. The attention factor works sometimes. The factor model constructed by the significant factors explain most of the excess return of cryptocurrencies.  相似文献   
80.
Showrooming, a phenomenon in which customers use brick-and-mortar stores to assess products and then purchase them from online retailers (o-retailers) for lower prices, is considered a great threat to traditional retailers (t-retailers). To combat showrooming, many t-retailers have executed price matching which enables customers to pay o-retailers' lower prices for the identical product. To avoid direct competition with t-retailers who execute price matching, many o-retailers have begun to sell differentiated products from t-retailers, which weakens the information advantage to customers from practicing showrooming. Motivated by these observations, we construct a duopoly game, where a t-retailer and an o-retailer sell products in a same category, to study the profitabilities of product differentiation and price matching in the context of showrooming. The results show that in the scenario without price matching, the o-retailer is likely to benefit from product differentiation only when the o-retailer's differentiated product is more popular with customers than the t-retailer's product. However, in the price matching scenario, the o-retailer also has the opportunity to benefit from product differentiation when the o-retailer's differentiated product is less popular with customers than the t-retailer's product, and product differentiation can be a win-win strategy for the two retailers under certain conditions. Considering the o-retailer's product differentiation decision, the t-retailer is only likely to execute price matching if the non-digital attributes of the product category sold by two retailers are not very obvious.  相似文献   
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