Space time neural networks for tether operations in space

A space shuttle flight scheduled for 1992 will attempt to prove the feasibility of operating tethered payloads in earth orbit. due to the interaction between the Earth's magnetic field and current pulsing through the tether, the tethered system may exhibit a circular transverse oscillation referred to as the 'skiprope' phenomenon. Effective damping of skiprope motion depends on rapid and accurate detection of skiprope magnitude and phase. Because of non-linear dynamic coupling, the satellite attitude behavior has characteristic oscillations during the skiprope motion. Since the satellite attitude motion has many other perturbations, the relationship between the skiprope parameters and attitude time history is very involved and non-linear. We propose a Space-Time Neural Network implementation for filtering satellite rate gyro data to rapidly detect and predict skiprope magnitude and phase. Training and testing of the skiprope detection system will be performed using a validated Orbital Operations Simulator and Space-Time Neural Network software developed in the Software Technology Branch at NASA's Lyndon B. Johnson Space Center

Learning characteristics of a space-time neural network as a tether skiprope observer

The Software Technology Laboratory at the Johnson Space Center is testing a Space Time Neural Network (STNN) for observing tether oscillations present during retrieval of a tethered satellite. Proper identification of tether oscillations, known as 'skiprope' motion, is vital to safe retrieval of the tethered satellite. Our studies indicate that STNN has certain learning characteristics that must be understood properly to utilize this type of neural network for the tethered satellite problem. We present our findings on the learning characteristics including a learning rate versus momentum performance table

Notes on noncommutative supersymmetric gauge theory on the fuzzy supersphere

In these notes we review Klimcik's construction of noncommutative gauge theory on the fuzzy supersphere. This theory has an exact SUSY gauge symmetry with a finite number of degrees of freedom and thus in principle it is amenable to the methods of matrix models and Monte Carlo numerical simulations. We also write down in this article a novel fuzzy supersymmetric scalar action on the fuzzy supersphere

Proceedings of the Second Joint Technology Workshop on Neural Networks and Fuzzy Logic, volume 2

Documented here are papers presented at the Neural Networks and Fuzzy Logic Workshop sponsored by NASA and the University of Texas, Houston. Topics addressed included adaptive systems, learning algorithms, network architectures, vision, robotics, neurobiological connections, speech recognition and synthesis, fuzzy set theory and application, control and dynamics processing, space applications, fuzzy logic and neural network computers, approximate reasoning, and multiobject decision making

Casimir-like tunneling-induced electronic forces

We study the quantum forces that act between two nearby conductors due to electronic tunneling. We derive an expression for these forces by calculating the flux of momentum arising from the overlap of evanescent electronic fields. Our result is written in terms of the electronic reflection amplitudes of the conductors and it has the same structure as Lifshitz's formula for the electromagnetically mediated Casimir forces. We evaluate the tunneling force between two semiinfinite conductors and between two thin films separated by an insulating gap. We discuss some applications of our results.Comment: 8 pages, 3 figs, submitted to Proc. of QFEXT'05, to be published in J. Phys.

Attentional bias towards threat in sexually victimized Hispanic women: A dot probe study

Objective: The current study examined attention bias toward threat in Hispanic college women exposed to lifetime sexual victimization in childhood, adulthood, and both childhood and adulthood. Response latencies and attention bias scores were compared between victimized and non-victimized individuals. Design: Participants were 20 women exposed to adulthood sexual victimization (AS group), 15 exposed to childhood sexual victimization (CS group), 8 exposed to both childhood and adulthood sexual assault (revictimization: RV group), and 20 not endorsing sexual victimization (NS group). They were asked to complete the dot-probe task. Results: The CS group and RV group were combined to create the CS-RV group. Among the AS and CS-RV groups, response latencies were faster when attention was engaged to threat than when attention was engaged to non-threat. The NS group did not demonstrate such differences. When response latencies were compared among the three groups, the CS-RV group had slower response latencies than the NS group. The CS-RV and AS groups revealed similarly significantly elevated bias scores towards threat words than the NS group. Conclusion: Hispanic college women exposed to lifetime sexual victimization display elevated levels of attention bias compared to non-victimized women. Further, the current findings align with an integrative cognitive model for explaining maladaptive informational processing in trauma victims

How expensive is treating patients in a center of excellence for rheumatoid arthritis in Colombia?

We aimed to estimate the cost of treating patients with rheumatoid arthritis (RA) in a Center of Excellence (CoE) for rheumatic diseases located in Bogotá, Colombia. We performed a cost analysis from the standard cost estimation of a CoE program for RA care. We estimated costs of consultations, laboratory and imaging tests, and pharmacological treatment from the measurement of the health care resource utilization of the CoE standard protocol according to the activity level of the disease (DAS28). Costing process was done following the recommendation of the Colombian Institute of Health Technology Assessment (IETS, in Spanish). Mean, minimum and maximum costs were reported annually for a type case depending on severity and classified as Remission, low disease activity (LDA), moderate disease activity (MDA) and severe disease activity -SDA- (with and without bDMARD). All costs were reported in American dollars, using the average exchange rate from January to December of 2018, reported by Banco de la República de Colombia: US$1 =$2,951.3 Colombian pesos. Mean total direct medical cost to treat a patient in remission is US$235.7 (213.0-336.4), in LDA is US325.2 (288.0-464.6) and in MDA is US$835.5 ($573.1-$2,187.1). There is a considerable increase in direct medical costs from a patient in SDA and SDA+Biologics: US$2,555.5 ($2,301.1-$3,890.9) to US$8,032.4 ($7,564.4-$8,400.3). The largest share of the cost was related to drugs, representing 39.9% for Remission, 53.6% for LDA, 75.2 for MDA, and in SDA and SDA+Biologics the proportion of what is spent on drugs for RA treatment is 88.5% and 96.7%, respectively. As the severity of the disease increases, the expenditure rate on drugs rises over the total of each activity level. With the introduction of the biological therapy, the treatment of RA is expensive, however, the CoE is an efficient way of care for RA

Quality of life and the relationship with family income in patients with rheumatoid arthritis

Objectives: To evaluate the quality of life (QoL) of patients with rheumatoid arthritis (RA) using the Quality of life in Rheumatoid Arthritis (RAQol) questionnaire. Also, to explore its relationship with income in patients attended at a specialized RA center in Bogotá, Colombia, 2018. Methods: We performed a descriptive study. The RAQol version in Spanish was applied to RA patients. The scale of the RAQol has a score from 1-10, where 10 is associated with better QoL. We excluded patients with psychological or psychiatric disorders. We asked about the monthly family income according to the Colombian minimum wage. Descriptive epidemiology was performed for each variable. A comparison of means regarding age and RAQol score was carried out. Therefore, we performed a bivariate analysis in order to explore the relationship between income and QoL, reporting Odds Ratios (OR) and confidence intervals 95% (CI95%). Results related to family income were reported in US$with the average exchange rate for 2018. Results: We interviewed 310 patients, 92$265, 47% between US$266- US$530, 9% between US$531-US$795 and 3% more than US$1300. Patients with an income greater than US$531 per/month had a higher average score in the RAQoL scale (7.1, SD5.5). The relationship of having a score lower than 6 in the RAQoL and a monthly income lower than US$530 showed an OR of 2.48 IC95% (0.99-6.22) (P=0.03). Conclusions: Our study showed that patient with a low income reports a lower QoL. Further research is needed to evaluate the alternatives that can improve QoL in patients with RA

Strange matter in rotating compact stars

We have constructed equations of state involving various exotic forms of matter with large strangeness fraction such as hyperon matter, Bose-Einstein condensates of antikaons and strange quark matter. First order phase transitions from hadronic to antikaon condensed and quark matter are considered here. The hadronic phase is described by the relativistic field theoretical model. Later those equations of state are exploited to investigate models of uniformly rotating compact stars. The effect of rotation on the third family branch for the equation of state involving only antikaon condensates is investigated. We also discuss the back bending phenomenon due to a first order phase transition from $K^-$ condensed to quark matter.Comment: 8 pages, 4 figures; Plenary talk delivered at Strangeness in Quark Matter (SQM) 2004 held in Cape Town, South Africa from 15-20 September; Accepted for publication in the proceedings in Journal of Physics