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1.
本文运用动态回归模型对我国的税收收入进行分析,有效分析了税收增长的滞后作用,对我国税收收入进行了合理的预测;并通过实例对模型进行验证,实践证明预测模型与实际情况拟合很好。  相似文献   

2.
人工神经网络的应用于纳税评估,为税务税务稽查的建立分类预测模型.从分析的结果可以看出,模型具有良好的预测效果,能为提高税收管理的针对性和有效性提出一些参考建议,以提高税收征管的水平.  相似文献   

3.
组合预测能够充分利用已知信息,从而提高预测精度.通过建立预测模型与预测对象的关系数据模型,利用离散化属性数据值来建立知识表达系统和决策表,并依据粗糙集理论计算组合预测模型中各单一模型的权系数,将该方法运用到我国R&D经费投入预测中,从而证明了该方法的可行性和有效性.  相似文献   

4.
在油气田的开发过程中,由于新区块的投产、规模化的开发调整和三次采油方案的实施等因素影响,会出现多峰的产量变化模式,而传统的HCZ模型属于单峰预测模型,不能适用于多峰的产量变化的预测。本文在已建立的HCZ多峰预测模型基础上,对HCZ多峰预测模型进行无因次化处理,建立了HCZ多峰预测模型无因次关系式,通过预测模型典型曲线的拟合求解,进而对油田的产量进行预测。通过实例的应用表明,本文提出的HCZ模型典型曲线在多峰预测中的应用是实用有效的。  相似文献   

5.
技术性贸易措施造成的经济损失是完全可以计量的.技术性贸易措施经济损失预测就是在已经获取某些评价指标值的基础上,通过所建立的经济损失预测模型,对技术性贸易措施给出口企业造成的损失进行预测.本文采用BP神经网络法构建了经济损失预测模型,预测准确率高达92.99%.预测结果表明,模型融合了各指标对企业应对技术性贸易措施的影响,指标的选择和模型的构建都是科学合理的,为我国出口企业的技术性贸易措施经济损失预测提供了新的思路.  相似文献   

6.
利用<中国统计年鉴>公布的数据,采用自回归自适应滤波方法建立了图书、期刊和报纸出版数量的预测模型,并对2010年的图书、期刊、报纸出版数量进行了预测.模型预测检验表明,除了期刊总印数、报纸种数和报纸总张数的预测模型外,其他预测模型的预测精度都非常高.  相似文献   

7.
本文分别建立了四川省工业利润总额方面的GMDH自回归预测模型和AC预测模型,然后针对它们的预测效果建立了GMDH-AC组合预测模型。并将组合预测结果与实际值以及单一的GMDH模型、AC模型的预测效果进行了分析和比较,表明了所述方法的有效性和可行性,从而为预测工业利润总额及其它宏观经济预测指标在选择预测方法提供了参考。  相似文献   

8.
快递量是我国经济结构至关重要的一部分,所以快递量的精确预测对我国经济结构的调整有重要的意义。本文利用1995年至2016年的相关数据,分别应用二次指数平滑模型、多项式曲线预测模型、建立ARIMA模型对数据进行预测和分析,再通过对这三种预测方法分别赋予不同的权重建立加权组合预测模型来改进预测误差,通过比较分析得出算子组合模型预测的精度更高,并运用该组合预测对2017年至2020年的快递量进行预测。  相似文献   

9.
何晓庆  蔡娜 《软科学》2013,27(1):141-144
组合方法首先选取支持向量机预测算法和一阶指数平滑法对经济时间序列分别进行预测,来建立模糊自适应变权重组合预测模型。为对比模糊自适应变权重的经济时间序列组合预测模型的预测效果,选取了两种定值加权组合预测模型:平均加权模型、误差平方和最小组合预测模型。通过实验比较分析:模糊自适应变权重组合预测可以综合利用各单项预测方法的优点,比单一模型预测结果精度有了很大提高,且优于定值加权组合预测,在经济时间序列的预测方面有较高的应用价值。  相似文献   

10.
杨俊峰 《中国科技信息》2010,(10):119-120,123
本文主要研究运用GM(1,1)模型对软件缺陷数进行预测。首先是列举建立软件缺陷数预测模型的灰色理论;其次建立了基于GM(1,1)模型的软件缺陷数预测模型;最后是运用建立的模型对ISS软件缺陷数进行预测,效果很好。  相似文献   

11.
This study examined how students who had no prior experience with videoconferencing would react to the use of videoconferencing as an instructional medium. Students enrolled in seven different courses completed a questionnaire at the beginning of the semester and again at the end of the semester. Students at the origination and remote sites did not differ in their reactions toward videoconferencing but there was a significant difference for gender. Women reacted less favorably to videoconferencing. Compared to the beginning of the semester, students reported significantly less positive attitudes toward taking a course through videoconferencing at the end of the semester. There were no significant differences in students' attitudes toward videoconferencing across courses at the beginning of the semester but there were significant differences across the courses at the end of the semester. The results suggest the need for better preparation for both students and instructors.  相似文献   

12.
Ajoint study by Prof. ZHANG Zhibin from the CAS Institute of Zoology and his co-workers from Norway, US and Swiss have indicated that historical outbreaks of migratory locusts in China were associated with cold spells, suggesting that China's projected climate warming could decrease the pest's numbers. The study was published in Proceedings of theNational Academy of Sciences on 17 September, 2007.  相似文献   

13.
A computer-mediated group is a complex entity whose members exchange many types of information via multiple means of communication in pursuit of goals specific to their environment. Over time, they coordinate technical features of media with locally enacted use to achieve a viable working arrangement. To explore this complex interaction, a case study is presented of the social networks of interactions and media use among members of a class of computer-supported distance learners. Results show how group structures associated with project teams dominated who communicated with whom, about what, and via which media over the term, and how media came to occupy their own communication niches: Webboard for diffuse class-wide communication; Internet Relay Chat more to named others but still for general communication across the class; and e-mail primarily for intrateam communication. Face-to-face interaction, occurring only during a short on-campus session, appears to have had a catalytic effect on social and emotional exchanges. Results suggest the need to structure exchanges to balance class-wide sharing of ideas with subgroup interactions that facilitate project completion, and to provide media that support these two modes of interaction.  相似文献   

14.
CAS should stick to the principle of rendering service to, and giving impetus for, the development of China's science enterprise by making S&T innovations, said CAS President LU Yongxiang. The CAS president made the remarks in a recent talk to communicate the gist of the winter session of the Party's Leading-member Group at CAS, which was held from 7 to 11 January in Beijing.  相似文献   

15.
Electronic data interchange (EDI) provides means for interorganizational communication, creates network externalities, requires an advanced information technology (IT) infrastructure, and relies on standards. In the diffusion of such innovations, institutional involvement is imperative. Such institutions contain governmental agencies, national and global standardization organizations, local government, and nonprofit private organizations like industry associations. The last type of organizations we call intermediating institutions. They intermediate or coordinate ("inscribe") the activities of a group of would-be adopters. Unfortunately, little is known of how these organizations shape the EDI diffusion trajectory. In this article we examine one specific type of intermediating organizations?industry associations?and how they advanced the EDI diffusion process in the grocery sectors of Hong Kong, Denmark and Finland. We identify six institutional measures, placed into a matrix formed by the mode of involvement (influence vs. regulation) and the type of diffusion force (supply push vs. demand pull), that can be mobilized to further the EDI diffusion. Industry associations were found to be active users of all these measures to varying degrees. Their role was critical especially in knowledge building, knowledge deployment, and standard setting. Furthermore, institutional involvement varied due to policy and cultural contingencies and power dependencies.  相似文献   

16.
With great care, Dr. ZHOU Zhonghe takes out a package wrapped by cotton tissue from a drawer and says: "This is the gem of our collections: the fossil of a bird that lived 125 million years ago!" Then, pointing at a tiny mound, he explains: "Look, this is the claw and that is the head. It was in the egg shell and ready to hatch ... The species fell into a family of waterside inhabitants."  相似文献   

17.
The increasing prospects of digital piracy has prompted the perceived need by electronic publishers to adopt technical systems of protection, and governments to reform their copyright laws. This article is a preliminary study of the management of intellectual property by electronic publishers, defined as those involved in the production of online databases, and CD-ROMs. It focuses on three main issues: (1) how electronic publishers view the increasing threat of piracy; (2) the methods of protection employed to protect intellectual property in digital format; and (3) the importance of technological protection of intellectual property in electronic publications. The analysis is based on a sample of 23 UK electronic publishers. The interviews revealed an interesting assortment of protection methods and did not show that technological protection was a preferred way. Instead, the means of protection, in addition to copyright law, comprised niche markets, pricing, trust, bad publicity, and nontechnical and technical means.  相似文献   

18.
Long-standing conflict between domain name registrants and trademark holders prompted the Internet Corporation for Assigned Names and Numbers (ICANN) to create a global, mandatory arbitration procedure known as the Uniform Dispute Resolution Policy (UDRP). The UDRP has been used in 2166 cases involving 3938 domain names as of 1 November 2000. The policy gives the initiator of a complaint, generally a trademark holder, the right to choose which ICANN-accredited dispute resolution service provider (RSP) will handle the case. During the preparation of the UDRP,some feared that complainant selection would lead to "forum shopping" that might bias the results. This article performs a statistical assessment of the forum-shopping thesis and finds support for it. There are statistically significant differences in the various RSPs' propensity to take away names from defendants; there are also major differences in the number of cases brought to each RSP. RSPs who take away names have the larger share of cases. The study examines other variables that might explain differences in market share, such as price, the plaintiff's nationality, or the time taken to decide a case. It finds that nationality and time also are correlated with market share. The study concludes that shopping for a favorable outcome is an important factor in the UDRP.  相似文献   

19.
Prof. Raymond C.K. Chen, a neuropsychologist with the CAS Institute of Psychology, has made novel progress in his studies of schizophrenia. His work has been reported by a recent issue of Behavioural Neurology.  相似文献   

20.
The main premise of this article is that in information societies generally, and in virtual social contexts particularly, a distinctive style of interaction to facilitate the communication of difference, heterotopic communication , has emerged. It rests on two cultural foundations: an ideological belief in the positive, socially integrating power of communication, and a prevailing ethic of instrumental rationality, subjective individualism, and strategically practiced self-interest. The former is demonstrated by the use of simulation and spectacle as sources of information; exhibitionism/voyeurism as a communicative style; and the awareness of surveillance. The latter is seen in the competitive use of knowledge as a commodity; a surface globalism masking deep parochialism; lateral as well as vertical information inequity; and the use of public versus private as strategies for engagement rather than as spaces. Those who engage in heterotopic communication resort to their 'own devices' both in the sense of personal agendas, strategies, interests, and interpretations, and in the form of the telecommunication tools that help realize them. These personal and technological devices allow individuals with the right educational and technical resources to avoid exposure to disagreement, difference, or other information that does not serve their direct purposes or reflect their particular views of the world; yet they also help convey the appearance of openness, availability, and cooperation. This style of interaction is used strategically in combination with information and communication technologies to gain social or economic advantages, but it may encourage social separatism and parochialism, inhibit the negotiation of disputes, and emphasize competing interests.  相似文献   

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