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21.
城市自生群落具有重要的生态服务功能与潜力,但因其外貌不被公众所接受而难以在城市公共空间中应用。将群落生态学和设计学相结合,探索一种介入栽培植物对城市自生群落进行改良,最终形成具有一定美学价值的植物群落的途径。实验以植物群落设计美学原理和种间竞争原理为依据,向已经演替1年的城市自生群落中引入63种栽培植物,按照分层的方式对群落进行改良。3年的观测结果表明,有61.9%的栽培植物可以在城市自生群落中定居并建立优势,能对76.7%的自生植物起到抑制作用,使55.8%的自生植物消失。相比城市自生群落,改良后的群落美观度提高29.4%,公众接受度提高24%,群落的物种丰富度提高至2.29倍。相比一般的人工植物群落,改良后的群落可以节约58.2%的建植成本,降低83.9%的浇水成本和67.8%的除草成本。实验证明改良设计是一种可行的群落设计途径,能有效提高群落的物种丰富度和美学价值,同时让自然参与群落设计过程,实现人与自然的合作。 相似文献
22.
This paper aims to comprehensively uncover bank risk factors from qualitative textual risk disclosures reported in financial statements, which contain a huge amount of information on bank risks. We propose a new semi‐supervised text mining approach named naive collision algorithm to analyse the textual risk disclosures, which can more accurately identify bank risk factors compared with the typical unsupervised text mining approach. We identified 21 bank risk factors in total, which is far more than identified in previous studies. We further analyse the importance of each bank risk factor and how the importance of each risk factor changes over time. 相似文献
23.
In state owned enterprises (SOEs), taxes are a dividend to the controlling shareholder, the state, but a cost to other shareholders. We examine publicly traded firms in China and find significantly lower tax avoidance by SOEs relative to non-SOEs. The differences are pronounced for locally versus centrally-owned SOEs and during the year of SOE term performance evaluations. We link our results to managerial incentives through promotion tests, finding that higher SOE tax rates are associated with higher promotion frequencies of SOE managers. Our results suggest managerial incentives and tax reporting are conditional on the ownership structure of the firm. 相似文献
24.
应用双指耦合结构和枝节加载谐振器(Stub-loaded Resonator,SLR)实现了一款基于阶梯阻抗谐振器(Stepped Impedance Resonator,SIR)的滤波器。该滤波器具有3个通带,带外抑制较好,工作频段提高。通过调整阻抗比可调节第二、三通带的谐振频率;SLR结构能够增加通带数量;SLR结构和双指耦合结构均能改善滤波器的S参数。HFSS软件仿真表明,3个通带的中心频率分别为3.5 GHz、6.6 GHz、9.2 GHz,对应的分数带宽分别为5.7%、3%、2%,S11分别为-18 dB、-22 dB、-24 dB,通带内的S21分别为-1.8 dB、-1 dB、-1 dB。电路的测量结果与仿真结果较为吻合。该滤波器在5G通信的低频段具有应用前景。 相似文献
25.
Muzammel Shah 《Business Strategy and the Environment》2019,28(5):771-785
The objective of the study was to develop a valid measurement scale for green human resource management (HRM). Even though the common practices of green HRM have been presented in much of the literature, the previous studies focused only on a small number of functions in integrating environmental management with HRM. Additionally, the measurement of green HRM practices still calls for empirical validation. The two‐stage methodology of structural equation modeling in AMOS was employed for data analysis. Exploratory factor analysis revealed seven dimensions of the construct measured by 28 items. Confirmatory factor analysis confirmed the factor structure. The measuring instruments revealed convergent and discriminant validity. Several model fit indices indicated the model fitness. The study provided supplementary evidence on the underlying structure of the construct that can be valuable to researchers and practitioners in this area. 相似文献
26.
《Journal of World Business》2019,54(4):322-334
While the extant literature has examined the influence of controlling and non-controlling principals on the internationalization decisions of emerging market firms, heterogeneity among non-controlling principals is largely ignored. The risk characteristics of different groups of owners, shaped by their institutional environments, could contribute to the differences in their preferences for firm internationalization. In this paper, we draw insights from institutional theory and behavioral risk perspective to examine the risk propensities and risk perceptions of various non-controlling principals, such as pressure-resistant (FIIs and mutual funds) and pressure-sensitive (banks, insurance companies and lending institutions) institutional investors. Empirical results from a sample of 2364 unique Indian firms during the 2005–2014 time-period show that, after controlling for firm-level resources and capabilities identified in prior literature, the ownership share of different types of institutional investors is associated with firms’ international investments differently. While pressure-sensitive institutional investors, such as banks and insurance companies, are not supportive of foreign investments by firms, pressure-resistant institutional investors, such as FIIs and mutual funds, are supportive of this strategic decision. Furthermore, our results show that the family ownership in a firm (measured in terms of family shareholding) further lowers the preference of pressure sensitive institutional investors for internationalization, whereas family ownership positively moderates the pressure resistant investors towards internationalization. 相似文献
27.
A control block trade can be explained by the expectation of financial gains, shared by all shareholders, or by the expectation of private benefits, exclusive to the buyer and possibly at the expense of other shareholders’ rents. The market for corporate control contributes to social welfare when it improves the efficiency of the allocation of resources. When the objective of a block transaction is private benefits, social welfare may be negatively impacted as minority shareholders could withdraw from the market. Therefore the estimation of private benefits would allow the efficiency of the market for corporate control to be assessed. Specifically, the aim of this paper is to calculate private benefits in the Spanish market for partial control. Using a sample of partial control transactions over the period 1990–2016, we find that the median of private benefits is negative, therefore it appears that there is no inefficient use of resources in the Spanish partial control market as a whole, however private costs are detected. The variability of private benefits is explained in a significant way by variables related to the control structure of the target firm, such as the controlling position of the buyer after the transaction, the contestability of control and the cross-shareholdings between the buyer and large shareholders. Performance and the size of the firm are significant as well. 相似文献
28.
Jonathan Fletcher 《European Journal of Finance》2019,25(13):1234-1249
I use the sequential approach of Harvey and Liu ([2018]. Lucky factors (Working Paper). Duke University) to build linear factor models in U.K. stock returns among a set of 13 candidate factors using individual stocks and three groups of test portfolios between July 1983 and December 2017. My study finds that the Market factor is the dominant factor in reducing mispricing in individual stocks and test portfolios regardless of the pricing error metric used. The Market factor has a bigger impact when using a value weighting pricing error metric. Whether a second factor is used or not depends upon which metric is used for mispricing and the time period examined. My study finds support for a two-factor model for the whole sample period of the Market factor and the Conservative Minus Aggressive (CMA) factor of Fama and French ([2015]. “A five-factor asset pricing model.” Journal of Financial Economics 116: 1–22) when giving greater weight to the mispricing of larger companies. 相似文献
29.
Using an extended LHARG model proposed by Majewski et al. (2015, J Econ, 187, 521–531), we derive the closed-form pricing formulas for both the Chicago Board Options Exchange VIX term structure and VIX futures with different maturities. Our empirical results suggest that the quarterly and yearly components of lagged realized volatility should be added into the model to capture the long-term volatility dynamics. By using the realized volatility based on high-frequency data, the proposed model provides superior pricing performance compared with the classic Heston–Nandi GARCH model under a variance-dependent pricing kernel, both in-sample and out-of-sample. The improvement is more pronounced during high volatility periods. 相似文献
30.
作为推动国民经济增长和促进社会稳定的基础力量,中小企业在市场中扮演着最活跃的经济主体。与大企业相比,中小企业有其鲜明的成长特征,从动态演进视角选取体量规模、生命周期、要素需求三个维度,系统探讨了中小企业的差异化特征。结论显示:体量规模特征反映在个体与群体以及经济板块之间;生命周期特征体现在死亡陷阱和空间格局演变上;要素需求特征会根据阶段创新内容的不同做出适时调整。 相似文献