Chow's theorem and universal holonomic quantum computation

A theorem from control theory relating the Lie algebra generated by vector fields on a manifold to the controllability of the dynamical system is shown to apply to Holonomic Quantum Computation. Conditions for deriving the holonomy algebra are presented by taking covariant derivatives of the curvature associated to a non-Abelian gauge connection. When applied to the Optical Holonomic Computer, these conditions determine that the holonomy group of the two-qubit interaction model contains $SU(2) \times SU(2)$. In particular, a universal two-qubit logic gate is attainable for this model.Comment: 13 page

Ocean services user needs assessment. Volume 1: Survey results, conclusions and recommendations

An interpretation of environmental information needs of marine users, derived from a direct contact survey of eight important sectors of the marine user community is presented. Findings of the survey and results and recommendations are reported. The findings consist of specific and quantized measurement and derived product needs for each sector and comparisons of these needs with current and planned NOAA data and services. The following supportive and reference material are examined: direct contact interviews with industry members, analyses of current NOAA data gathering and derived product capabilities, evaluations of new and emerging domestic and foreign satellite data gathering capabilities, and a special commercial fishing survey conducted by the Jet Propulsion Laboratory (JPL)

Independent Orbiter Assessment (IOA): Analysis of the remote manipulator system

The results of the Independent Orbiter Assessment (IOA) of the Failure Modes and Effects Analysis (FMEA) and Critical Items List (CIL) are presented. The IOA approach features a top-down analysis of the hardware to determine failure modes, criticality, and potential critical items (PCIs). To preserve independence, this analysis was accomplished without reliance upon the results contained within the NASA FMEA/CIL documentation. The independent analysis results for the Orbiter Remote Manipulator System (RMS) are documented. The RMS hardware and software are primarily required for deploying and/or retrieving up to five payloads during a single mission, capture and retrieve free-flying payloads, and for performing Manipulator Foot Restraint operations. Specifically, the RMS hardware consists of the following components: end effector; displays and controls; manipulator controller interface unit; arm based electronics; and the arm. The IOA analysis process utilized available RMS hardware drawings, schematics and documents for defining hardware assemblies, components and hardware items. Each level of hardware was evaluated and analyzed for possible failure modes and effects. Criticality was assigned based upon the severity of the effect for each failure mode. Of the 574 failure modes analyzed, 413 were determined to be PCIs

Distributed control for COFS 1

An overview is given of the work being done at NASA LaRC on developing the Control of Flexible Structures (COFS) 1 Flight Experiment Baseline Control Law. This control law currently evolving to a generic control system software package designed to supply many, but not all, guest investigators. A system simulator is also described. It is currently being developed for COFS-1 and will be used to develop the Baseline Control Law and to evaluate guest investigator control schemes. It will be available for use whether or not control schemes fall into the category of the Baseline Control Law. First, the hardware configuration for control experiments is described. This is followed by a description of the simulation software. Open-loop sinusoid excitation time histories are next presented both with and without a local controller for the Linear DC Motor (LDCM) actuators currently planned for the flight. The generic control law follows and algorithm processing requirements are cited for a nominal case of interest. Finally, a closed-loop simulation study is presented, and the state of the work is summarized in the concluding remarks

Viscosity calculated in simulations of strongly-coupled dusty plasmas with gas friction

A two-dimensional strongly-coupled dusty plasma is modeled using Langevin and frictionless molecular dynamical simulations. The static viscosity $\eta$ and the wave-number-dependent viscosity $\eta(k)$ are calculated from the microscopic shear in the random motion of particles. A recently developed method of calculating the wave-number-dependent viscosity $\eta(k)$ is validated by comparing the results of $\eta(k)$ from the two simulations. It is also verified that the Green-Kubo relation can still yield an accurate measure of the static viscosity $\eta$ in the presence of a modest level of friction as in dusty plasma experiments.Comment: 6 pages, 3 figures, Physics of Plasmas invited pape

Role of Angiotensin II in Hemorrhagic Hypotension in the Rat

Author Institution: Department of Physiology, Wright State UniversityThe purpose of this study was to evaluate the role of the renin-angiotensin system in the acute regulation of blood pressure following hemorrhage in the anesthetized rat. Eleven Sprague-Dawley rats were anesthetized with sodium pentobarbital. After control blood pressure recordings from the femoral artery were made, the rats were hemorrhaged 6 ml/kg body weight. Forty minutes after hemorrhage, the Angiotensin II antagonist, l-SAR-8-ALA-Angiotensin II (saralasin), was infused (10 /Ltg/min/kg) for 35 min. Hemorrhage resulted in a 53% decrease in blood pressure which recovered to 82% of the control blood pressure in 40 minutes. Infusion of saralasin resulted in a 24% decrease (p <0.01) in blood pressure within 15 min. Recovery from saralasin infusion occurred within 10 min as blood pressure increased back to control values. A second group of 5 rats was not hemorrhaged but was infused with saralasin. There were no significant changes in blood pressure; although, a tendency to decrease was noted reflecting the increase in plasma renin activity which occurs with anesthesia. It was concluded that the renin-angiotensin system can respond rapidly to a hypotensive event and aid in the restoration of blood pressure within minutes

Velocity field distributions due to ideal line vortices

We evaluate numerically the velocity field distributions produced by a bounded, two-dimensional fluid model consisting of a collection of parallel ideal line vortices. We sample at many spatial points inside a rigid circular boundary. We focus on ``nearest neighbor'' contributions that result from vortices that fall (randomly) very close to the spatial points where the velocity is being sampled. We confirm that these events lead to a non-Gaussian high-velocity ``tail'' on an otherwise Gaussian distribution function for the Eulerian velocity field. We also investigate the behavior of distributions that do not have equilibrium mean-field probability distributions that are uniform inside the circle, but instead correspond to both higher and lower mean-field energies than those associated with the uniform vorticity distribution. We find substantial differences between these and the uniform case.Comment: 21 pages, 9 figures. To be published in Physical Review E (http://pre.aps.org/) in May 200

Design of experiments for non-manufacturing processes : benefits, challenges and some examples

Design of Experiments (DoE) is a powerful technique for process optimization that has been widely deployed in almost all types of manufacturing processes and is used extensively in product and process design and development. There have not been as many efforts to apply powerful quality improvement techniques such as DoE to improve non-manufacturing processes. Factor levels often involve changing the way people work and so have to be handled carefully. It is even more important to get everyone working as a team. This paper explores the benefits and challenges in the application of DoE in non-manufacturing contexts. The viewpoints regarding the benefits and challenges of DoE in the non-manufacturing arena are gathered from a number of leading academics and practitioners in the field. The paper also makes an attempt to demystify the fact that DoE is not just applicable to manufacturing industries; rather it is equally applicable to non-manufacturing processes within manufacturing companies. The last part of the paper illustrates some case examples showing the power of the technique in non-manufacturing environments

Applications of spectral methods to turbulent magnetofluids in space and fusion research

Recent and potential applications of spectral method computation to incompressible, dissipative magnetohydrodynamics are surveyed. Linear stability problems for one dimensional, quasi-equilibria are approachable through a close analogue of the Orr-Sommerfeld equation. It is likely that for Reynolds-like numbers above certain as-yet-undetermined thresholds, all magnetofluids are turbulent. Four recent effects in MHD turbulence are remarked upon, as they have displayed themselves in spectral method computations: (1) inverse cascades; (2) small-scale intermittent dissipative structures; (3) selective decays of ideal global invariants relative to each other; and (4) anisotropy induced by a mean dc magnetic field. Two more conjectured applications are suggested. All the turbulent processes discussed are sometimes involved in current carrying confined fusion magnetoplasmas and in space plasmas

Saari's homographic conjecture for planar equal-mass three-body problem under a strong force potential

Donald Saari conjectured that the $N$-body motion with constant configurational measure is a motion with fixed shape. Here, the configurational measure $\mu$ is a scale invariant product of the moment of inertia $I=\sum_k m_k |q_k|^2$ and the potential function $U=\sum_{i<j} m_i m_j/|q_i-q_j|^\alpha$, $\alpha >0$. Namely, $\mu = I^{\alpha/2}U$. We will show that this conjecture is true for planar equal-mass three-body problem under the strong force potential $\sum_{i<j} 1/|q_i-q_j|^2$