A study of wing body blending for an advanced supersonic transport

Increases in supersonic cruise lift drag ratio were sought at Mach numbers 2.2 and 2.7 using wing body planform and thickness blending. Constrained twist and camber optimization was performed in the presence of nacelles. Wing and fuselage thickness distributions were optimized for either minimum volume wave drag or minimum total pressure wave drag. The zero leading edge suction lift drag ratios were determined for three wing planforms. The magnitude of the effect of leading edge suction on attainable lift drag ratio was defined on one planform and estimation of available leading edge suction was made

Break in the VHE spectrum of PG 1553+113: new upper limit on its redshift?

PG 1553+113 is a known BL Lac object, newly detected in the GeV-TeV energy range by H.E.S.S and MAGIC. The redshift of this source is unknown and a lower limit of $z > 0.09$ was recently estimated. The very high energy (VHE) spectrum of PG 1553+113 is attenuated due to the absorption by the low energy photon field of the extragalactic background light (EBL). Here we correct the combined H.E.S.S and MAGIC spectrum of PG 1553+113 for this absorption assuming a minimum density of the evolving EBL. We use an argument that the intrinsic photon index cannot be harder than $\Gamma = 1.5$ and derive an upper limit on the redshift of $z < 0.69$. Moreover, we find that a redshift above $z = 0.42$ implies a possible break of the intrinsic spectrum at about 200 GeV. Assuming that such a break is absent, we derive a much stronger upper limit of $z < 0.42$. Alternatively, this break might be attributed to an additional emission component in the jet of PG 1553+113. This would be the first evidence for a second component is detected in the VHE spectrum of a blazar.Comment: revised version submitted to Ap

Rules and Standards: A Critique of Two Critical Theorists

This article attacks the Critical Legal Studies ( CLS ) position that the rule of law is impossible. The article focuses on legal form, where two CLS scholars have asserted that the two choices for the form of a legal directive, rules and standards, each embody the conflicting ideological positions that characterize the political world. While acknowledging the inter-connectedness of form and substance, the article takes issue with the conclusion that because views regarding the proper form and substance of law differ on both descriptive and prescriptive levels, law then simply becomes the embodiment of the moral, political, and economic choices we make. The article suggests that the CLS position fails to adequately confront the claims of one side in the political debate, the individualists, that law as rules is more an example of restraint on choice and policy in law than a manifestation of that choice

Study of hypersonic propulsion/airframe integration technology

An assessment is done of current and potential ground facilities, and analysis and flight test techniques for establishing a hypersonic propulsion/airframe integration technology base. A mach 6 cruise prototype aircraft incorporating integrated Scramjet engines was considered the baseline configuration, and the assessment focused on the aerodynamic and configuration aspects of the integration technology. The study describes the key technology milestones that must be met to permit a decision on development of a prototype vehicle, and defines risk levels for these milestones. Capabilities and limitations of analysis techniques, current and potential ground test facilities, and flight test techniques are described in terms of the milestones and risk levels

Taking advantage of misclassifications to boost classification rate in decision fusion

This paper presents methods to boost the classification rate in decision fusion with partially redundant information. This is accomplished by utilizing the information of known mis- classifications of certain classes to systematically modify class output. For example,, if it is known beforehand that tool A mis- classifies class 1 as often as class 2, then it appears to be prudent to integrate that information into the reasoning process if class 1 is indicated by tool B and class 2 is observed by tool A. Particularly this preferred mis-classification information is contained in the asymmetric (cross-correlation) entries of the confusion matrix. An operation we call cross-correlation is performed where this information is explicitly used to modify class output before the first fused estimate is calculated. We investigate several methods for cross-correlation and discuss the advantages and disadvantages of each. We then apply the concepts introduced to the diagnostic realm where we aggregate the output of several different diagnostic tools. We show how the proposed approach fits into an information fusion architecture and finally present results motivated from diagnosing on-board faults in aircraft engines