14,775 research outputs found

    Dynamic analysis of the large deployable reflector

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    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?

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    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

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    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?

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    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

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    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

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    [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

    The Rise and Fall of Article 2

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    In August 13,2001 the National Conference of Commissioners on Uniform State Laws voted eighty-nine to fifty-three to reject the Amendments to Article 2 of the Uniform Commercial Code that had just been approved in May by the American Law Institute. The vote followed a last minute effort by the Article 2 drafting committee to amend the scope provisions of Article 2 in response to continuing criticism from representatives of the software and information industries. Several months later, at the request of the NCCUSL leadership, amended Article 2 with its revised scope provision was withdrawn from the agenda of the ALI Council in order to avoid its certain defeat. In the months that followed, the Article 2 drafting committee approved a new version that did not amend the basic scope section of Article 2 but did amend the definition of goods to exclude information. The Amendments, as revised, were then approved by NCCUSL at its annual meeting in August 2002. The Article 2 Amendments thus return yet again to the ALI Council and, in the event of its approval, to the ALI membership in May 2003
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