Dynamic analysis of the large deployable reflector

The Large Deployable Reflector (LDR) is to be an astronomical observatory orbiting above Earth's obscuring atmosphere and operating in the spectral range between 30 microns and 1000 microns wavelength. The LDR will be used to study such astronomical phenomena as stellar and galactic formation, cosmology, and planetary atmospheres. The LDR will be the first observatory to be erected and assembled in space. This distinction brings with it several major technological challenges such as the development of ultra-lightweight deployable mirrors, advanced mirror fabrication techniques, advanced structures, and control of vibrations due to various sources of excitation. The purpose of this analysis is to provide an assessment of the vibrational response due to secondary mirror chopping and LDR slewing. The dynamic response of two 20-m LDR configurations was studied. Two mirror support configurations were investigated for the Ames concept, the first employs a six-strut secondary mirror support structure, while the second uses a triple-bipod support design. All three configurations were modeled using a tetrahedral truss design for the primary mirror support structure. Response resulting from secondary mirror chopping was obtained for the two Ames configurations, and the response of the primary mirror from slewing was obtained for all three configurations

Why the Government Should Not Regulate Internet Telephony?

The Federal Communications Commission has requested comments on the regulation of voice telephone services delivered over the Internet, dubbed "VoIP" or Voice over Internet Protocol. This paper examines whether there is a need to regulate VoIP. We conclude that there is no economic rationale for regulating VoIP and that consumers will likely be worse off if VoIP is regulated. Furthermore, the emergence of new technologies, such as VoIP, is rapidly eroding the rationale for continuing to regulate local telephone services.

Bandwidth for the People

President Bush recently called for "universal, affordable access to broadband technology by the year 2007." This paper examines the economic strengths and weaknesses of different policies for achieving that vision. We argue that removing price and "unbundling" regulations at the wholesale and retail levels would help increase the diffusion of broadband. Banning Internet access taxes would be beneficial, but we believe such a ban would be less effective than removing these regulatory barriers to competition. We argue against subsidizing broadband to increase penetration because subsidies are likely to result in economic inefficiencies. The study also examines state policies that could be used to enhance the rollout of broadband, including reducing the regulatory burden associated with right-of-way access and eliminating retail price regulation.

Variation in Boilerplate: Rational Design or Random Mutation?

Standard contract doctrine presumes that sophisticated parties choose their terminology carefully because they want courts or counterparts to understand what they intended. The implication of this “Rational Design” model of rational behavior is that courts should pay careful attention to the precise phrasing of contracts. Using a study of the sovereign bond market, we examine the Rational Design model as applied to standard-form contracting. In NML v. Argentina, federal courts in New York attached importance to the precise phrasing of the boilerplate contracts at issue. The industry promptly condemned the decision for a supposedly erroneous interpretation of a variant of a hoary boilerplate clause. Utilizing data on how contracting practices responded to the decision, we ask whether the market response indicates that parties in fact intended for the small variations in their contract language to embody a particular meaning. We find the data supports a model closer to random mutation rather than rational design

Effects of Gear Modifications on the Trawl Performance and Catching Efficiency of the West Coast Upper Continental Slope Groundfish Survey Trawl

Since 1984, annual bottom trawl surveys of the west coast (California–Washington) upper continental slope (WCUCS) have provided information on the abundance, distribution, and biological characteristics of groundfish resources. Slope species of the deep-water complex (DWC) are of particular importance and include Dover sole, Microstomus pacificus; sablefish, Anoplopoma fimbria; shortspine thornyhead, Sebastolobus alascanus; and longspine thornyhead, S. altivelis. In the fall of 1994, we conducted an experimental gear research cruise in lieu of our normal survey because of concerns about the performance of the survey trawl. The experiment was conducted on a soft mud bottom at depths of 460–490 m off the central Oregon coast. Treatments included different combinations of door-bridle rigging, groundgear weight, and scope length. The experimental design was a 2 ´ 2 ´ 2 factorial within a randomized complete-block. Analysis of variance was used to examine the effects of gear modifications on the engineering performance of the trawl (i.e. trawl dimensions, variation in trawl dimensions, and door attitude) and to determine if catch rates in terms of weight and number of DWC species and invertebrates were affected by the gear modifications. Trawl performance was highly variable for the historically used standard trawl configuration. Improvements were observed with the addition of either a 2-bridle door or lighter ground gear. Changes in scope length had relatively little effect on trawl performance. The interaction of door bridle and ground gear weight had the most effect on trawl performance. In spite of the standard trawl’s erratic performance, catch rates of all four DWC species and invertebrates were not significantly different than the 2-bridle/heavy combination, which did the best in terms of engineering performance. The most important factor affecting DWC catch rates was ground gear. Scope length and the type of door bridle had little effect on DWC catch rates. Subsequent revisions to survey gear and towing protocol and their impact on the continuity of the slope survey time series are discussed

Chaos Theory and the Justice Paradox

[T]he laws have mistakes, and you can\u27t go writing up a law for everything that you can imagine. When you reach an equilibrium in biology you\u27re dead. As we approach the Twenty-First Century, the signs of social disarray are everywhere. Social critics observe the breakdown of core structures – the nuclear family, schools, neighborhoods, and political groups. As these traditional social institutions have disintegrated, the law has expanded to fill the void. There are more laws, more lawyers, and more use of legal mechanisms to accomplish social goals than at any other time in history. The custodians and interpreters of the American legal system have become, whether they like it or not, the center of the universe. Lawyers and legal academics are deeply conflicted about this newfound prominence. The legal profession is searching, even struggling, to define its role in a changing society. Much of this angst comes from a feeling that the legal community hasn\u27t made much progress in resolving what I will term the Justice Paradox. To understand the paradox, one must focus on the purposes of legal rules. Legal rules that determine liability and/or impose sanctions have both a distributive function and a behavior modification function. That is, the rules redistribute wealth or entitlements between the immediate parties to any particular dispute, and they also influence the behavior of future parties who may find themselves similarly situated. The justice of all legal rules must therefore be evaluated from two distinct perspectives: (1) Does the law accomplish justice between the parties to any particular dispute? We can call this Present Justice ; and (2) Does the law appropriately regulate the conduct of other parties likely to have similar disputes in the future, making it less likely that similar misfortune will befall others who can learn from the experience of these litigants? We might call this Future Justice. The paradox arises from two propositions. First, both criteria must be satisfied in order to achieve a just outcome. Second, these two criteria of justice are usually intractably opposed. Simply put, you can\u27t have it both ways. Thus, we aspire to a just society that satisfies the essential conditions of both Present and Future Justice, and yet we live in a world that often forces us to choose between one or the other

nsolvency Experience, Risk-Based Capital, and Prompt Corrective Action in Property-Liability Insurance

In December 1992, the National Association of Insurance Commissioners (NAIC) adopted a life-health insurer risk-based capital (RBC) formula and model law that became effective with the 1993 annual statement filed in March 1994. In principle, well-designed RBC requirements can help achieve an efficient reduction in the expected costs of insolvencies. They can provide incentives for insurers to operate safely in cases where market incentives are weak due to government mandated guarantees of insurer obligations or asymmetries regarding solvency between insurers and buyers. RBC requirements also may facilitate or encourage prompt corrective action by solvency regulators by helping regulators to identify weak insurers and giving regulators legal authority to intervene when capital falls below specified levels. RBC requirements may force regulators to act in amore timely manner when confronted with external pressure to delay action. However, RBC capital requirements have a number ofpotential limitations. Unavoidable imperfections in any meaningful RBC system will likely distort some insurer decisions in undesirable and unintended ways. RBC requirements by themselves will do little or nothing to help regulators determine when an insurer s reported capital (surplus) is overstated due to understatement of liabilities or overstatement of assets. A well-designed RBC system should minimize costs associated with misclassification of insurers. The system should be able to identify a high proportion of troubled companies early enough to permit regulators to take prompt corrective action and should identify as troubled only a minimal proportion of financially sound insurers. This study analyzes data on solvent and insolvent property-liability insurers to determine whether modifications in the NAIC s RBC formula can improve its ability to predict firms that subsequently fail without substantially increasing the proportion of surviving insurers that are incorrectly predicted to fail. It uses logistic regression models to investigate whether changes in the weight for the major components in the RBC formula and incorporation of information on company size and organizational form improve the tradeoff between Type I error rates (the percentage of insurers that later failed that are incorrectly predicted not to fail) and the Type II error rates (the percentage of surviving insurers that are incorrectly predicted to fail). The data analyzed were for 1989-91 for firms that subsequently failed and for firms that survived through the first nine months of 1993. The authors make four main conclusions. First, less than half of the companies that later failed had RBC ratios within the proposed ranges for regulatory and company action. Second, total and component RBC ratios generally are significantly different for failed and surviving firms based on univariate tests. Third, estimation of multiple logistic regression models of insolvency risk indicated that allowing the weights of the RBC component to vary and including firm size and organizational form variables generally produce a material improvement in the tradeoff between sample Type I and Type II error rates. And, fourth,the RBC models are noticeably less successful in predicting large firm insolvencies than in predicting smaller insolvencies. Regarding the estimated weights in the logistic regression models, a major conclusion is the reserve component of the NAIC risk-based capital formula, which accounts for half of industry risk-based capital, has virtually no predictive power in any of the tests conducted. Given the high costs associated with large failures and the inferior performance of the models in predicting large insolvencies, a higher payoff in terms of reduced insolvency costs is likely to be achieved by developing models that perform better for large firms.