Near Real-Time Closed-Loop Optimal Control Feedback for Spacecraft Attitude Maneuvers

Optimization of spacecraft attitude maneuvers can significantly reduce attitude control system size and mass, and extend satellite end-of-life. Optimal control theory has been applied to solve a variety of open-loop optimal control problems for terrestrial, air, and space applications. However, general application of real-time optimal controllers on spacecraft for large slew maneuvers has been limited because open-loop control systems are inherently vulnerable to error and the computation necessary to solve for an optimized control solution is resource intensive. This research effort is focused on developing a near real-time optimal control (RTOC) system for spacecraft attitude maneuvers on the Air Force Institute of Technology\u27s 2nd generation simulated satellite, SimSat II. To meet the end goal of developing a RTOC controller, necessary preliminary steps were completed to accurately characterize SimSAT II\u27s mass properties and attitude control system. Using DIDO, a pseudospectral-based optimal control solver package, to continuously solve and execute a sequence of optimized open-loop control solutions in near real-time, the RTOC controller can optimally control the state of the satellite over the course of a large angle slew maneuver. In this research, simulation and experimental results clearly demonstrate the benefit of RTOC versus other non-optimal control methods for the same maneuver

The True Compass: No Federal Question in a State Law Claim

This is the published version

Drop the Shoe: A Law of Personal Jurisdiction

Personal jurisdiction standards outlined in International Shoe Co. v. Washington have proven to be inadequate. This Article begins in Part II with an examination of the origins of the International Shoe minimum contacts test, and then in Part III analyzes and critiques the opinion and the test. Part IV looks at later Supreme Court cases that attempt to refine and apply the test, and Part V looks at the same pattern for other federal courts and state courts. These Parts lead to the conclusion that the minimum contacts test should be abandoned in favor of a new law for personal jurisdiction, and so to Part VI, which proposes that the Court should “drop the Shoe.” After an examination in Part VII of whether state boundaries should be considered in the formulation of a new law personal jurisdiction, the article proposes new law in Part VIII. In order to determine the practicality of the proposed new law, the Article applies it to the facts presented in previous Supreme Court personal jurisdiction cases, and to some of today’s commonly recurring factual situation, in Part IX

The Need for a New National Court

By any measure, the Supreme Court is tremendously overburdened. Statistics speak clearly on this point; sometimes they shout. After the caseload relief provided by the Judges\u27 Bill, 4 which was passed in I925 and took effect during the I928 Term, the Supreme Court caseload grew slowly for thirty years. Beginning in the I96os, growth sharply accelerated, and during the I970S and I98os, the numbers exploded

In Search of the Transaction or Occurrence: Counterclaims

Tthe “transaction or occurrence” is the cornerstone of the federal joinder rules, including counterclaims, cross-claims, and joinder of parties. The rule that has produced by far the most reported decisions is Fed. R. Civ. P. 13(a), the compulsory counterclaim rule, so this article limits itself to counterclaims. The article looks at the history and intended meaning of the transaction or occurrence, proceeds to analyze and critique many court decisions on counterclaims, and proposes a new key phrase for the joinder rules

A latitudinal cline in the efficacy of endogenous signals: evidence derived from retinal cone contraction in fish.

Like many physiological systems synchronised to the light:dark cycle, retinomotor movements in 'lower' vertebrates are controlled by both the ambient illumination and input from endogenous circadian oscillators. In the present study, we examine the relative influence of these two signals in various species of teleost fish with different latitudes of origin. We find equatorial species show very strong endogenous control. The cones of the glowlight tetra, for example, continue to go through undiminished cycles of contraction and relaxation that mirror the previous light:dark cycle for at least two weeks in continual darkness. To quantify the relative effectiveness of the ambient light compared with endogenous signals in causing cone contraction, the degree to which seven teleost species responded to light during the dark phase of their light:dark cycle was examined. In this situation the retina receives conflicting instructions; while the light is acting directly to cause light adaptation, any endogenous signal tends to keep the retinal elements dark adapted. The further from the equator a species originated, the more its cones contracted in response to such illumination, suggesting animals from higher latitudes make little use of endogenous oscillators and rely more on ambient illumination to control behaviours. Equatorial species, however, rely on internal pacemakers to a much greater degree and are relatively insensitive to exogenous light signals. Because these data are consistent with published observations in systems as diverse as melatonin synthesis in Arctic reindeer and the behaviour of regional populations of Drosophila, latitudinal clines in the efficacy of circadian oscillators may be a common feature among animals

Regulatory Oversight and Safety of Probiotic Use

Saccharomyces boulardii probiotics should be used with caution for management of Clostridium difficile infections in hospitalized patients

Toward an understanding of transfusion-related acute lung injury: statement of a consensus panel

Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/73845/1/j.0041-1132.2004.04347.x.pd