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排序方式: 共有1592条查询结果,搜索用时 15 毫秒
1.
We introduce a new type of heavy‐tailed distribution, the normal reciprocal inverse Gaussian distribution (NRIG), to the GARCH and Glosten‐Jagannathan‐Runkle (1993) GARCH models, and compare its empirical performance with two other popular types of heavy‐tailed distribution, the Student's t distribution and the normal inverse Gaussian distribution (NIG), using a variety of asset return series. Our results illustrate that there is no overwhelmingly dominant distribution in fitting the data under the GARCH framework, although the NRIG distribution performs slightly better than the other two types of distribution. For market indexes series, it is important to introduce both GJR‐terms and the NRIG distribution to improve the models’ performance, but it is ambiguous for individual stock prices series. Our results also show the GJR‐GARCH NRIG model has practical advantages in quantitative risk management. Finally, the convergence of numerical solutions in maximum‐likelihood estimation of GARCH and GJR‐GARCH models with the three types of heavy‐tailed distribution is investigated.  相似文献   
2.
Social movements have been viewed as vehicles through which the concerns of poor and marginalized groups are given greater visibility within civil society, lauded for being the means to achieve local empowerment and citizen activism, and seen as essential in holding the state to account and constituting a grassroots mechanism for promoting democracy. However, within development studies little attention has been paid to understanding how social movements can affect trajectories of development and rural livelihood in given spaces, and how these effects are related to movements’ internal dynamics and their interaction with the broader environment within which they operate. This paper addresses this theme for the case of social movements protesting contemporary forms of mining investment in Latin America. On the basis of cases from Peru and Ecuador, the paper argues that the presence and nature of social movements has significant influences both on forms taken by extractive industries (in this case mining) and on the effects of this extraction on rural livelihoods. In this sense, one can usefully talk about rural development as being co-produced by movements, mining companies, and other actors, in particular the state. The terms of this co-production, however, vary greatly among different locations, reflecting the distinct geographies of social mobilization and of mineral investment, as well as the varying power relationships among the different actors involved.  相似文献   
3.
从自然资源投入产出关系分析入手 ,论述了资源产业的两大产业群———资源开发业与资源再生产业 ,揭示了其内外经济关系。  相似文献   
4.
Many see Nanotechnology as the technology that will underlie the next Schumpeterian wave creating new opportunities for wealth and job creation. Further it is a process based or materials technology. Yet all currently used models of innovation are based on assembled products or service products and these simply do not recognize the differences in materials products nor the “enabling” nature of Nanotechnologies. If nanotechnology is poised to become the economic engine of this millennium and if current models of innovation, which are utilized, by policy makers and firm based strategist alike are based on technology product paradigms that are dissimilar to the realities of nanotechnology and other process-based technologies then there is cause for concern.Here the authors provide a model and supporting cases demonstrating a new process or materials based innovation model that is based on the tight coupling between product and process innovation of not only Nanotechnology-based products but other process-based products. This is an important finding, because it identifies and remedies a gap in the literature associated with earlier process and product innovation models. For process-based products like materials, food, chemicals and nanotechnologies any change to the manufacturing processes results in significant changes in end product features. The implications of this model to practice are considered.  相似文献   
5.
We explore why some firms in the extractive industries disclose mineral reserve quantum in their annual reports and others do not. We propose that the firms' reserve disclosure policies are a function of the extent of information asymmetries, as well as information production, litigation and proprietary costs. More specifically, we propose that a firm's decisions to disclose reserves in the annual report are a function of the stage of the firm's operations, use of project financing, and the cost of measuring reserves. Empirical tests are confirmatory.  相似文献   
6.
介绍了重油悬浮床加氢裂化工艺的最新发展,对国内新开发的悬浮床加氢裂化工艺特点作了介绍。并将悬浮床加氢和三种重油轻质化工艺——固定床加氢、延迟焦化、重油催化裂化在技术经济上作了分析对比。在原油品质越来越差的今天,针对劣质重油而开发的的悬浮床加氢裂化工艺具有非常广阔的应用前景。  相似文献   
7.
文章通过对己内酰胺精制装置改扩建项目的对比分析,探讨改用“环己酮氨肟化技术”后,己内酰胺浓缩部分采用新工艺去杂的可能性,提出适合新技术条件下的己内酰胺浓缩工艺,并运用流程模拟软件“ASPEN”对新老工艺进行模拟计算,分析新工艺去除杂质的可行性。  相似文献   
8.
林业企业信息化面临的问题及对策   总被引:5,自引:0,他引:5  
面对信息化时代的到来,企业信息化成为企业生存和发展的关键,文章从目前我国林业企业的现状出发,分析了林业企业信息化中存在的主要问题,并提出了相应的对策。  相似文献   
9.
产业融合是信息化进程中呈现的一种产业新范式。产业间的关联性和对效益最大化的追求是产业融合发展的内在动力,在不同的产业领域内,产业融合以不同的方式演进。产业融合带来创新性优化效应、竞争性结构效应、组织性结构效应、竞争性能力效应、消费性能力效应及区域效应等。产业之间的渗透融合是21世纪产业发展的大趋势,我国政府应制定相应的措施来促进我国产业融合及产业的健康发展。  相似文献   
10.
武义青 《价值工程》2007,26(9):49-51
本文利用第一次全国经济普查资料,对河北省制造业中的钢铁、装备制造、石化、医药、建材、食品、纺织服装等主导产业的竞争力进行了评价和分析。  相似文献   
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