A software control system for the ACTS high-burst-rate link evaluation terminal

Control and performance monitoring of NASA's High Burst Rate Link Evaluation Terminal (HBR-LET) is accomplished by using several software control modules. Different software modules are responsible for controlling remote radio frequency (RF) instrumentation, supporting communication between a host and a remote computer, controlling the output power of the Link Evaluation Terminal and data display. Remote commanding of microwave RF instrumentation and the LET digital ground terminal allows computer control of various experiments, including bit error rate measurements. Computer communication allows system operators to transmit and receive from the Advanced Communications Technology Satellite (ACTS). Finally, the output power control software dynamically controls the uplink output power of the terminal to compensate for signal loss due to rain fade. Included is a discussion of each software module and its applications

A Decade of Debt

This book presents evidence that public debts in the advanced economies have surged in recent years to levels not recorded since the end of World War II, surpassing the heights reached during the First World War and the Great Depression. At the same time, private debt levels, particularly those of financial institutions and households, are in uncharted territory and are (in varying degrees) a contingent liability of the public sector in many countries. Historically, high leverage episodes have been associated with slower economic growth and a higher incidence of default or, more generally, restructuring of public and private debts. A more subtle form of debt restructuring in the guise of “financial repression” (which had its heyday during the tightly regulated Bretton Woods system) also importantly facilitated sharper and more rapid debt reduction than would have otherwise been the case from the late 1940s to the 1970s. It is conjectured here that the pressing needs of governments to reduce debt rollover risks and curb rising interest expenditures in light of the substantial debt overhang (combined with the widespread “official aversion” to explicit restructuring) are leading to a revival of financial repression—including more directed lending to government by captive domestic audiences (such as pension funds), explicit or implicit caps on interest rates, and tighter regulation on cross-border capital movements.

The Modern History of Exchange Rate Arrangements: A Reinterpretation

We develop a novel system of re-classifying historical exchange rate regimes. One difference between our study and previous classification efforts is that we employ an extensive data base on market-determined parallel exchange rates. Our 'natural' classification algorithm leads to a stark reassessment of the post-war history of exchange rate arrangements. When the official categorization is a form of peg, roughly half the time our classification reveals the true underlying monetary regime to be something radically different, often a variant of a float. Conversely, when official classification is floating, our scheme routinely suggests that the reality was a form of de facto peg. Our new classification scheme points to a complete rethinking of economic performance under alternative exchange rate regimes. Indeed, the breakup of Bretton Woods had a far less dramatic impact on most exchange rate regimes than is popularly believed. Also, contrary to an influential empirical literature, our evidence suggests that exchange rate arraignments may be quite important for growth, trade and inflation. Our newly compiled monthly data set on market-determined exchange rates goes back to 1946 for 153 countries.

Serial Default and the "Paradox" of Rich to Poor Capital Flows

Lucas (1990) argued that it was a paradox that more capital does not flow from rich countries to poor countries. He rejected the standard explanation of expropriation risk and argued that paucity of capital flows to poor countries must instead be rooted in externalities in human capital formation favoring further investment in already capital rich countries. In this paper, we review the various explanations offered for this paradox.' There is no doubt that there are many reasons why capital does not flow from rich to poor nations yet the evidence we present suggests some explanations are more relevant than others. In particular, as long as the odds of non repayment are as high as 65 percent for some low income countries, credit risk seems like a far more compelling reason for the paucity of rich-poor capital flows. The true paradox may not be that too little capital flows from the wealthy to the poor nations, but that too much capital (especially debt) is channeled to debt intolerant serial defaulters.

MUNICIPAL HOME RULE IN COLORADO

If the actual adoption of constitutional municipal home rule is the product of the West, there can be little doubt that it is the product of the experience of the East. For had not New York and Massachusetts and Pennsylvania, to mention a few salient examples, demonstrated the almost incredible extents to which interference by legislatures in the local affairs of their creatures, the municipalities, might reach, it is safe to say that the chances are preponderant that the western states themselves would have had to suffer through the evils consequent on legislative butting before municipal home rule would have made the headway it has made in our great trans-Mississippi territory. So when we learn that the municipal home-rule provisions of Washington and Oklahoma and Arizona are actually integral parts of the original respective state constitutions concerned, we must not regard them as spontaneously conceived solutions of an age-old problem, but merely as ameliorative provisions adopted in the wake of a long eastern experience, and in flattering reflection on the few older western states which saw fit to enact home-rule amendments to their state constitutions. I do not mean for a moment to imply that the aforementioned constitutional provisions acted as dei ex machinis by which cities became immune from legislative interference in their local matters; the point is that the states noted lack the long preliminary struggle for municipal home rule that we find elsewhere

Addicted to Dollars

Dollarization, in a broad sense, is increasingly a defining characteristic of many emerging market economies. How important is this trend quantitatively and how important is it for the conduct of monetary policy and the choice of exchange rate regimes? Though these questions have become a hot topic in both the theory and policy literature, most efforts are remarkably uninformed by evidence, in no small part because meaningful data has been lacking, except for a very narrow range of assets. This paper attempts to move the discussion forward and shed light on the critical questions by proposing a measure of dollarization that is broad both conceptually and in terms of country coverage. We use this measure to identify trends in the evolution of dollarization in the developing world in the last two decades, and to ascertain the consequences that dollarization has had on the effectiveness of monetary and exchange rate policy. We find that, contrary to the general presumption in the literature, a high degree of dollarization does not seem to be an obstacle to monetary control or to disinflation. A level of dollarization does, however, appear to increase exchange rate pass-through, reinforcing the claim that fear of floating' is a greater problem for highly dollarized economies. We also review the developing countries' record in combating their addiction to dollars. Concretely, we try to explain why some countries have been able to avoid certain forms of the addiction, and examine the evidence on successful de-dollarization.

Debt Intolerance

This paper introduces the concept of "debt intolerance," which manifests itself in the extreme duress many emerging market economies experience at levels of indebtedness that would seem manageable by advanced country standards. The paper argues that "safe" external debt-to-GNP thresholds for debt-intolerant countries depend on the country's default and inflation history and may be as low as 15 percent in some cases. Debt intolerance is linked to the phenomenon of serial default that has plagued many countries over the past two centuries. Understanding and measuring debt intolerance is fundamental to assessing the problems of debt sustainability, debt restructuring, capital market integration, and the scope for international lending to ameliorate crises. The paper makes a first pass at quantifying debt intolerance, including delineating debtors' "clubs" and regions of vulnerability, based on a history of credit events for a large number of countries going back to the 1820s.macroeconomics, Debt Intolerance

Optimization of Strut Diameters in Lattice Structures

Additive manufactured lattice structures show a high potential for lightweight design. Currently, these structures have a periodical build-up, which leads to disadvantageous stress states. On the one hand, unfavorable bending loads on the single struts appear. This can be avoided by an adaption of the course of the structure to the main stress directions inside the part. On the other hand, different stress values are appearing inside the single struts. Therefore, a procedure for the optimization of the struts diameters is presented. Thus, it becomes possible to achieve equal stresses in the whole structure and gain a better lightweight performance.Mechanical Engineerin

Shifting Mandates: The Federal Reserve's First Centennial

The Federal Reserve's mandate has evolved considerably over the organization's hundred-year history. It was changed from an initial focus in 1913 on financial stability, to fiscal financing in World War II and its aftermath, to a strong anti-inflation focus from the late 1970s, and then back to greater emphasis on financial stability since the Great Contraction. Yet, as the Fed's mandate has expanded in recent years, its range of instruments has narrowed, partly based on a misguided belief in the inherent stability of financial markets. We argue for a return to multiple instruments, including a more active role for reserve requirements.Economic