一种便携式船舶导航系统设计

随着航海技术的不断发展,船舶设备也不断的进行改进和创新,以现代信息自动化为基础的便携式船舶导航系统也越来越重要了,可以客观的了解船舶航驶情况。描述了以FPGA＆DSP为核心的船舶航驶地理信息测量系统的研究,确定船舶航驶的最佳参数。在此基础上设计了一套便携式船舶导航参数检测装置。系统的硬件结构由前端电路、DSP信息处理模块、FPGA逻辑控制模块和自主导航驱动模块等组成;系统软件分为固件程序模块、导航信息采集模块、无线导航通信模块和信号处理模块等。     

Benefits Of Communications Infrastructure Capital In U.S. Economy

In this paper we empirically estimate the contribution of the communications infrastructure to the growth of output and productivity at the dis-aggregate industry and at the aggregate economy levels. The estimated value of the marginal benefits or the shadow price of the communications infrastructure capital is positive in each of 34 industries representing the major industrial sectors of the U.S. economy. This effect captures network externality benefits and can be interpreted as a willingness to pay by each industry for communications infrastructure capital services over and above their direct payments for communications services. These results suggest that an increase in communications infrastructure capital services reduces cost in all the industries and as a consequence that of the entire economy. The relatively high value of estimated total marginal benefits for the aggregate economy indicates a high social rate of return to the investments in communications infrastructure.     

Corporate Tax Reductions,Cross‐Border Ownership and Welfare

In this paper, a three‐country model incorporating the cross‐border ownership of stock and international firm relocation is constructed. Using this model, the effects of a reduction in the corporate tax on welfare in all three countries is examined. The findings indicate that if the country undertaking the reduction is moderately rich, and one of the two remaining countries is rich while the other country is poor, the tax reduction not only brings about a positive effect on its own welfare, but also increases the welfare of the rich foreign country and lowers that of the poor foreign country.     

The performance of venture capital investments: Do investors overreact?

Using a unique proprietary data set of over 5400 realized and unrealized venture capital investments between 1980 and 2005, we examine the impact of demand-related factors, e.g. entrepreneurial activity, as well as supply-related factors, i.e. money provided by VC investors, on the return of individual VC investments. This way, we are able to shed more light on the question whether volatile VC investment returns are rather driven by fundamental changes with regard to the number of attractive investment opportunities or by the overreaction by investors. We find that rising demand for VC, i.e. an increase in entrepreneurial activity, results initially in higher returns. However, our results also indicate that overreaction on the supply side can be observed, destroying deal-level results. Overfunding, specifically overinvesting seems to be a recurring characteristic of the VC industry. In fact, contra-cyclical investment strategies yield highest deal-level returns.     

Financial Exposure and the International Transmission of Financial Shocks

This paper analyzes the transmission mechanism of banking sector shocks in an international real business cycle model with heterogeneous bank sizes. We examine to what extent the financial exposure of the banking sector affects the transmission of foreign banking sector shocks. In our model, the more exposed domestic banks are to the foreign economy via lending to foreign firms, the greater are the spillovers from foreign financial shocks to the home economy. The model highlights the role of openness to trade and the dynamics of the terms of trade in the international transmission mechanism of banking sector shocks: spillovers from foreign banking sector shocks are greater the more open the home economy is to trade and the less the terms of trade respond to foreign shocks.     

Collateral and capital structure

We develop a dynamic model of investment, capital structure, leasing, and risk management based on firms' need to collateralize promises to pay with tangible assets. Both financing and risk management involve promises to pay subject to collateral constraints. Leasing is strongly collateralized costly financing and permits greater leverage. More constrained firms hedge less and lease more, both cross-sectionally and dynamically. Mature firms suffering adverse cash flow shocks may cut risk management and sell and lease back assets. Persistence of productivity reduces the benefits to hedging low cash flows and can lead firms not to hedge at all.     

Feedback effects of credit ratings

Rating agencies are often criticized for being biased in favor of borrowers, for being too slow to downgrade following credit quality deterioration, and for being oligopolists. Based on a model that takes into account the feedback effects of credit ratings, I show that: (i) rating agencies should focus not only on the accuracy of their ratings but also on the effects of their ratings on the probability of survival of the borrower; (ii) even when rating agencies pursue an accurate rating policy, multi-notch downgrades or immediate default may occur in response to small shocks to fundamentals; (iii) increased competition between rating agencies can lead to rating downgrades, increasing default frequency and reducing welfare.     

Investment cycles and startup innovation

We find that venture capital-backed startups receiving their initial investment in hot markets are more likely to go bankrupt, but conditional on going public, are valued higher on the day of their initial public offering, have more patents, and have more citations to their patents. Our results suggest that VCs invest in riskier and more innovative startups in hot markets (rather than just worse firms). This is particularly true for the most experienced VCs. Furthermore, our results suggest that increased capital in hot times plays a causal role in shifting investments to more novel startups by lowering the cost of experimentation for early stage investors and allowing them to make riskier, more novel, investments.     

Real exchange rate adjustment in European transition countries

In single-equation tests, real exchange rates show mean reversion for nine of 10 Central and Eastern European transition countries for the period January 1993 to December 2005. Because of the shift from controlled to market economies and accompanying crises, failed policy regimes and changes in exchange rate regimes, unit root tests for transition countries often require allowance for structural changes. Accounting for structural breaks gives substantially faster mean-reversion speeds than those found for major industrialized countries. These fast adjustment speeds are plausible: Transition countries had perhaps 10 years to make unprecedented adjustments required for accession to the European Union. A number of papers have applied non-linear models to the Central and Eastern European countries. This paper investigates four non-linear models and compares them with piece-wise linear break models. The break models appear superior in detecting mean reversion for the Central and Eastern European transition countries.     

Emerging markets and heavy tails

Emerging countries are held to be subject to more frequent and more pronounced external and internal shocks than their developed counter-parts. This suggests that key variables pertaining to their markets, including their exchange rates, will be marked by greater likelihood of extreme observations and large fluctuations. We focus on the hypothesis that compared to developed country exchange rates, emerging country exchange rates will be more pronouncedly heavy-tailed. We find support for the hypothesis using recently proposed robust tail index estimation methods which, in particular, perform well under heavy-tailed dependent GARCH processes that are often used for modeling exchange rates. According to the estimation results reported in the paper, variances may be infinite for several emerging country exchange rates. Tail index values ζ = p ∈ (2.6, 2.8) appear to be at the dividing boundary between the two sets of countries: while the moments of order p ∈ (2.6, 2.8) are finite for most of the developed country exchange rates, they may be (or are) infinite for most of the emerging country exchange rates. We also study the impact of the on-going financial and economic crisis, and find that heavy-tailedness properties of most exchange rates did not change significantly with the onset of the crisis. At the same time, some foreign exchange markets have experienced structural changes in their heavy-tailedness properties during the crisis.