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1.
在介绍软件无线电的产生、基本概念和系统结构的同时,分析了实现软件无线电的关键技术,并给出了基于目前器件技术水平的中频软件无线电流程框图的折衷方案,最后指出软件无线电技术的美好前景。 相似文献
2.
The nexus between government revenue and government expenditure has been an important topic in public economics. In this paper, we investigate evidence for cointegration and causality between government revenue and government expenditure for nine Asian countries. We use the recently developed bounds testing approach to cointegration and the conventional F-test to examine Granger causality. Our empirical results suggest that for three out of the nine countries government revenue and government expenditure are cointegrated. Our results on the direction of causation are mixed: (a) for Indonesia, Singapore, Sri Lanka in the short-run and for Nepal in both the short- and long-run we find support for the tax-and-spend hypothesis; (b) Indonesia and Sri Lanka are in conformity with the spend-and-tax hypothesis in the long-run; and (c) for other countries there is evidence of neutrality. 相似文献
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THE SQUARED ORNSTEIN-UHLENBECK MARKET 总被引:2,自引:0,他引:2
We study a complete market containing J assets, each asset contributing to the production of a single commodity at a rate that is a solution to the squared Ornstein-Uhlenbeck (Cox-Ingersoll-Ross) SDE. The assets are owned by K agents with CRRA utility functions, who follow feasible consumption/investment regimes so as to maximize their expected time-additive utility from consumption. We compute the equilibrium for this economy and determine the state-price density process from market clearing. Reducing to a single (representative) agent, and exploiting the relation between the squared-OU and squared-Bessel SDEs, we obtain closed-form expressions for the values of bonds, assets, and options on the total asset value. Typical model parameters are estimated by fitting bond price data, and we use these parameters to price the assets and options numerically. Implications for the total asset price itself as a diffusion are discussed. We also estimate implied volatility surfaces for options and bond yields. 相似文献
5.
Wolfram Elsner 《Local Economy》2004,19(3):249-263
Many regions have experienced long-run economic fluctuations generated by the life cycles of their dominant industrial clusters. During the downswings in the 1970s and 1980s, proactive structural policies were typically launched in German regions to combat job losses in their core clusters and to create new jobs in new industries. With respect to the German State of Bremen, this paper provides empirical evidence of: (1) a long-run regional downswing; (2) the potential job effects of proactive regional industrial policy programmes in terms of increasing regional employment, by safeguarding jobs in the regional core industries and creating new jobs in new growth industries; and (3) a time pattern in the job effects, which are related to the different generations of programmes. 相似文献
6.
We examine the spillover wealth effects of the Orange County, California bankruptcy announcement in December 1994 on municipal bonds, municipal bond funds, and bank stocks. This bankruptcy is prominent because of unprecedented losses and because it was caused by a highly leveraged derivatives strategy rather than a shortage of tax revenues and excess spending. We find contagion in the bond market with significantly negative abnormal returns for municipal bond funds without direct exposure to Orange County and for non‐Orange County municipal bonds. In addition, our findings suggest the contagion spills over to the common stocks of investment and commercial banks that deal in or use derivatives; however, the equities of banks unexposed to derivatives are not affected. 相似文献
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我国武器装备通用ATS(自动测试系统)经历了从引进、仿制到自行研制的过程,但是目前通用ATS总的局面是通用ATS不通用,这种局面主要是由于国内对通用ATS实现技术缺乏统一认识造成的。基于此,本文研究了与开发通用ATS密切相关的标准/规范、硬件配置技术、接口技术、集成测试软件开发环境技术。本文的研究结果适用于所有开发通用ATS的项目。 相似文献
9.
Probability theory in fuzzy sample spaces 总被引:2,自引:0,他引:2
This paper tries to develop a neat and comprehensive probability theory for sample spaces where the events are fuzzy subsets of The investigations are focussed on the discussion how to equip those sample spaces with suitable -algebras and metrics. In the end we can point out a unified concept of random elements in the sample spaces under consideration which is linked with compatible metrics to express random errors. The result is supported by presenting a strong law of large numbers, a central limit theorem and a Glivenko-Cantelli theorem for these kinds of random elements, formulated simultaneously w.r.t. the selected metrics. As a by-product the line of reasoning, which is followed within the paper, enables us to generalize as well as to bring together already known results and concepts from literature.Acknowledgement. The author would like to thank the participants of the 23rd Linz Seminar on Fuzzy Set Theory for the intensive discussion of the paper. Especially he is indebted to Professors Diamond and Höhle whose remarks have helped to get deeper insights into the subject. Additionally, the author is grateful to one anonymous referee for careful reading and valuable proposals which have led to an improvement of the first draft.This paper was presented at the 23rd Linz Seminar on Fuzzy Set Theory, Linz, Austria, February 5–9, 2002. 相似文献
10.
Robustness issues in multilevel regression analysis 总被引:8,自引:0,他引:8
A multilevel problem concerns a population with a hierarchical structure. A sample from such a population can be described as a multistage sample. First, a sample of higher level units is drawn (e.g. schools or organizations), and next a sample of the sub‐units from the available units (e.g. pupils in schools or employees in organizations). In such samples, the individual observations are in general not completely independent. Multilevel analysis software accounts for this dependence and in recent years these programs have been widely accepted. Two problems that occur in the practice of multilevel modeling will be discussed. The first problem is the choice of the sample sizes at the different levels. What are sufficient sample sizes for accurate estimation? The second problem is the normality assumption of the level‐2 error distribution. When one wants to conduct tests of significance, the errors need to be normally distributed. What happens when this is not the case? In this paper, simulation studies are used to answer both questions. With respect to the first question, the results show that a small sample size at level two (meaning a sample of 50 or less) leads to biased estimates of the second‐level standard errors. The answer to the second question is that only the standard errors for the random effects at the second level are highly inaccurate if the distributional assumptions concerning the level‐2 errors are not fulfilled. Robust standard errors turn out to be more reliable than the asymptotic standard errors based on maximum likelihood. 相似文献