Process Errors and Aspects for Higher Resolution in Conventional Stereolithography

Due to the rapid development of precision manufacturing technologies, there is a growing market need for appropriate rapid prototyping methods with higher resolution. This paper presents aspects for a general optimization of stereolithography accuracy and gives a deeper analysis of important process errors. Beside a higher precision due to improved optical components, it can be shown that for a better vertical resolution one must mainly reduce the penetration depth of the photopolymer. We found that this is also possible with conventional stereolithography materials by using a different wavelength, achieving cured rugged layers with a thickness of 20 micrometer. The major accuracy aspect lies in the understanding of the layer deposition process. A CFD (computational fluid dynamics) study helps to describe important phenomena of blade based coating techniques. As a result, the inaccuracy of the layer deposition is the general limiting factor in stereolithography. This knowledge can be directly applied to commercial stereolithography systems helping users to achieve higher process accuracy.Mechanical Engineerin

The impact of exchange rate movements on U.S. foreign debt

In 2001, the United States' net debt to the rest of the world jumped to $2.3 trillion, a level double that recorded in 1999. Much of the increase reflects the new borrowing undertaken by the country to finance its mounting current account deficit. A third of the change, however, can be traced to a simple accounting effect--the impact of a rising dollar on the value of U.S. assets held abroad.Debts, External ; Foreign exchange ; Capital movements ; Deficit financing

Could capital gains smooth a current account rebalancing?

A narrowing of the U.S. current account deficit through exchange rate movements is likely to entail a substantial depreciation of the dollar, as stressed in research by Obstfeld and Rogoff. We assess how the adjustment is affected by the high degree of financial integration in the world economy. A growing body of research emphasizes the increasing leverage in international financial positions, with industrialized economies holding substantial and growing financial claims on each other. Exchange rate movements then lead to valuation effects as the currency composition of a country's assets and liabilities are not matched. In particular, a dollar depreciation generates valuation gains for the United States by boosting the dollar value of much of its foreign-currency-denominated assets. We consider an adjustment scenario in which the U.S. net external debt is held constant. The key finding is that as the current account moves into balance, the pace of adjustment is smooth. Intuitively, the valuation gains from the depreciation of the dollar allow the United States to finance ongoing, albeit shrinking, current account deficits. We find that the smooth pattern of adjustment is robust to alternative scenarios, although the ultimate movements in exchange rates will vary under different conditionscurrent account, exchange rates, global imbalances

The changing nature of the U.S. balance of payments

Earnings on cross-border investments figure only marginally in net estimates of the U.S. current account, but they represent an increasingly large share of gross flows between the United States and other nations. Because these earnings fluctuate much more sharply than trade flows, they can be expected to create permanently higher current account volatility. Such increased volatility is not necessarily grounds for concern, however; it reflects an international sharing of risk that provides a buffer against domestic economic uncertainty.Balance of payments ; International economic relations ; Investments, Foreign

Could capital gains smooth a current account rebalancing?

A narrowing of the U.S. current account deficit through exchange rate movements is likely to entail a substantial depreciation of the dollar, as stressed in the widely cited contribution by Obstfeld and Rogoff (2005). We assess how the adjustment is affected by the high degree of international financial integration in the world economy. A growing body of research stresses the increasing leverage in international financial positions, with industrialized economies holding substantial and growing financial claims on each other. Exchange rate movements then leads to valuations effects as the currency compositions of a country's assets and liabilities are not matched. In particular, a dollar depreciation generates valuation gains for the U.S. by boosting the dollar value of the large amount of its foreign-currency denominated assets. We consider an adjustment scenario in which the U.S. net external debt is held constant. The key finding is that while the current account moves into balance, the pace of adjustment is smooth. Intuitively, the valuation gains stemming from the depreciation of the dollar allow the U.S. to finance ongoing, albeit shrinking, current account deficits. We find that the smooth pattern of adjustment is robust to alternative scenarios, although the ultimate movements in exchange rates are affected.Balance of trade ; Foreign exchange rates

The International Role of the Dollar and Trade Balance Adjustment

The pattern of international trade adjustment is affected by the continuing international role of the dollar and related evidence on exchange rate pass-through into prices. This paper argues that a depreciation of the dollar would have asymmetric effects on flows between the United States and its trading partners. With low exchange rate pass-through to U.S. import prices and high exchange rate pass-through to the local prices of countries consuming U.S. exports, the effect of dollar depreciation on real trade flows is dominated by an adjustment in U.S. export quantities, which increase as U.S. goods become cheaper in the rest of the world. Real U.S. imports are affected less because U.S. prices are more insulated from exchange rate movements — pass-through is low and dollar invoicing is high. In relation to prices, the effects on the U.S. terms of trade are limited: U.S. exporters earn the same amount of dollars for each unit shipped abroad, and U.S. consumers do not encounter more expensive imports. Movements in dollar exchange rates also affect the international trade transactions of countries invoicing some of their trade in dollars, even when these countries are not transacting directly with the United States.

International Capital Flows

The sharp increase in both gross and net capital flows over the past two decades has led to a renewed interest in their determinants. Most existing theories of international capital flows are in the context of models with only one asset, which only have implications for net capital flows, not gross flows. Moreover, there is no role for capital flows as a result of changing expected returns and risk-characteristics of assets as there is no portfolio choice. In this paper we develop a method for solving dynamic stochastic general equilibrium open-economy models with portfolio choice. We show why standard first and second-order solution methods no longer work in the presence of portfolio choice, and extend them giving special treatment to the optimality conditions for portfolio choice. We apply the solution method to a particular two-country, two-good, two-asset model and show that it leads to a much richer understanding of both gross and net capital flows. The approach highlights time-varying portfolio shares, resulting from time-varying expected returns and risk characteristics of the assets, as a potential key source of international capital flows.

Curbing unemployment in Europe: are there lessons from Ireland and the Netherlands?

Since the mid-1980s, unemployment rates in Ireland and the Netherlands have plummeted, while the average rate for the European Union has maintained its longtime high level. Ambitious labor market reforms_including wage moderation and the tightening of unemployment benefits_have helped to bring the Irish and Dutch rates down. Other European countries would benefit from adopting similar reforms, but they are unlikely to see the same dramatic improvement in their unemployment numbers.Unemployment - Netherlands ; Unemployment - Ireland ; Unemployment - Europe ; Economic policy - Europe

To what extent does productivity drive the dollar?

The continuing strength of the dollar has fueled interest in the relationship between productivity and exchange rates. An analysis of the link between the dollar's movements and productivity developments in the United States, Japan, and the euro area suggests that productivity can account for much of the change in the external value of the dollar over the past three decades.Foreign exchange rates ; Labor productivity ; Dollar, American

The income implications of rising U.S. international liabilities

Although the United States has seen its net liabilities surge in recent years, its investment income balance has remained positive-largely because U.S. firms operating abroad earn a higher rate of return than do foreign firms operating here. The continuing buildup in liabilities, however, should soon push the U.S. income balance below zero. In that event, net income flows will begin to boost the nation's current account deficit instead of reducing it.Liabilities (Accounting) ; Balance of payments