Phase-dependent X-ray observations of the beta Lyrae system: No eclipse in the soft band

We report on observations of the eclipsing and interacting binary beta Lyrae from the Suzaku X-ray telescope. This system involves an early B star embedded in an optically and geometrically thick disk that is siphoning atmospheric gases from a less massive late B II companion. Motivated by an unpublished X-ray spectrum from the Einstein X-ray telescope suggesting unusually hard emission, we obtained time with Suzaku for pointings at three different phases within a single orbit. From the XIS detectors, the softer X-ray emission appears typical of an early-type star. What is surprising is the remarkably unchanging character of this emission, both in luminosity and in spectral shape, despite the highly asymmetric geometry of the system. We see no eclipse effect below 10 keV. The constancy of the soft emission is plausibly related to the wind of the embedded B star and Thomson scattering of X-rays in the system, although it might be due to extended shock structures arising near the accretion disk as a result of the unusually high mass-transfer rate. There is some evidence from the PIN instrument for hard emission in the 10-60 keV range. Follow-up observations with the RXTE satellite will confirm this preliminary detection.Comment: to appear in A&A Letter

Comparison of Risk from Orbital Debris and Meteoroid Environment Models on the Extravehicular Mobility Unit (EMU)

A well-known hazard associated with exposure to the space environment is the risk of failure from an impact from a meteoroid and orbital debris (MMOD) particle. An extravehicular mobility unit (EMU) spacesuit impact during a US extravehicular activity (EVA) is of great concern as a large leak could prevent an astronaut from safely reaching the airlock in time resulting in a loss of life. A risk assessment is provided to the EVA office at the Johnson Space Center (JSC) by the Hypervelocity Impact Technology (HVIT) group prior to certification of readiness for each US EVA. Need to understand the effect of updated meteoroid and orbital debris environment models to EMU risk

Application of advanced on-board processing concepts to future satellite communications systems

An initial definition of on-board processing requirements for an advanced satellite communications system to service domestic markets in the 1990's is presented. An exemplar system architecture with both RF on-board switching and demodulation/remodulation baseband processing was used to identify important issues related to system implementation, cost, and technology development

An analytical and experimental investigation of resistojet plumes

As a part of the electrothermal propulsion plume research program at the NASA Lewis Research Center, efforts have been initiated to analytically and experimentally investigate the plumes of resistojet thrusters. The method of G.A. Simons for the prediction of rocket exhaust plumes is developed for the resistojet. Modifications are made to the source flow equations to account for the increased effects of the relatively large nozzle boundary layer. Additionally, preliminary mass flux measurements of a laboratory resistojet using CO2 propellant at 298 K have been obtained with a cryogenically cooled quartz crystal microbalance (QCM). There is qualitative agreement between analysis and experiment, at least in terms of the overall number density shape functions in the forward flux region

Image-based Recommendations on Styles and Substitutes

Humans inevitably develop a sense of the relationships between objects, some of which are based on their appearance. Some pairs of objects might be seen as being alternatives to each other (such as two pairs of jeans), while others may be seen as being complementary (such as a pair of jeans and a matching shirt). This information guides many of the choices that people make, from buying clothes to their interactions with each other. We seek here to model this human sense of the relationships between objects based on their appearance. Our approach is not based on fine-grained modeling of user annotations but rather on capturing the largest dataset possible and developing a scalable method for uncovering human notions of the visual relationships within. We cast this as a network inference problem defined on graphs of related images, and provide a large-scale dataset for the training and evaluation of the same. The system we develop is capable of recommending which clothes and accessories will go well together (and which will not), amongst a host of other applications.Comment: 11 pages, 10 figures, SIGIR 201

Phase operators, phase states and vector phase states for SU(3) and SU(2,1)

This paper focuses on phase operators, phase states and vector phase states for the sl(3) Lie algebra. We introduce a one-parameter generalized oscillator algebra A(k,2) which provides a unified scheme for dealing with su(3) (for k < 0), su(2,1) (for k > 0) and h(4) x h(4) (for k = 0) symmetries. Finite- and infinite-dimensional representations of A(k,2) are constructed for k < 0 and k > 0 or = 0, respectively. Phase operators associated with A(k,2) are defined and temporally stable phase states (as well as vector phase states) are constructed as eigenstates of these operators. Finally, we discuss a relation between quantized phase states and a quadratic discrete Fourier transform and show how to use these states for constructing mutually unbiased bases

Display/control requirements for VTOL aircraft

Quantative metrics were determined for system control performance, workload for control, monitoring performance, and workload for monitoring. Pilot tasks were allocated for navigation and guidance of automated commercial V/STOL aircraft in all weather conditions using an optimal control model of the human operator to determine display elements and design

Renormalization of Multiple qq-Zeta Values

In this paper we shall define the renormalization of the multiple $q$-zeta values (M$q$ZV) which are special values of multiple $q$-zeta functions $\zeta_q(s_1,...,s_d)$ when the arguments are all positive integers or all non-positive integers. This generalizes the work of Guo and Zhang (math.NT/0606076v3) on the renormalization of Euler-Zagier multiple zeta values. We show that our renormalization process produces the same values if the M$q$ZVs are well-defined originally and that these renormalizations of M$q$ZV satisfy the $q$-stuffle relations if we use shifted-renormalizations for all divergent $\zeta_q(s_1,...,s_d)$ (i.e., $s_1\le 1$). Moreover, when \qup our renormalizations agree with those of Guo and Zhang.Comment: 22 pages. This is a substantial revision of the first version. I provide a new and complete proof of the fact that our renormalizations satisfy the q-stuffle relations using the shifting principle of MqZV

Status of Outer Planet Global Reference Atmospheric Model (GRAM) Upgrades

The inability to test planetary spacecraft in the flight environment prior to a mission requires engineers to rely on ground-based testing and models of the vehicle and expected environments. One of the most widely used engineering models of the atmosphere is the Global Reference Atmospheric Model (GRAM) developed and maintained by the NASA Marshall Space Flight Center (MSFC). The NASA Science Mission Directorate (SMD) has provided funding support to upgrade the GRAMs