Using an instrumented manikin for Space Station Freedom analysis

One of the most intriguing and complex areas of current computer graphics research is animating human figures to behave in a realistic manner. Believable, accurate human models are desirable for many everyday uses including industrial and architectural design, medical applications, and human factors evaluations. For zero-gravity (0-g) spacecraft design and mission planning scenarios, they are particularly valuable since 0-g conditions are difficult to simulate in a one-gravity Earth environment. At NASA/JSC, an in-house human modeling package called PLAID is currently being used to produce animations for human factors evaluation of Space Station Freedom design issues. Presented here is an introductory background discussion of problems encountered in existing techniques for animating human models and how an instrumented manikin can help improve the realism of these models

A leaner, more skilled U.S. manufacturing workforce

While the U.S. manufacturing sector has contracted sharply since the early 1980s, employment in high-skill manufacturing occupations has risen by an impressive 37 percent. An investigation of the growth in high-skill manufacturing jobs reveals that virtually all of the nation's industries have shared in this trend. Moreover, skill upgrading has occurred in all parts of the country, even those experiencing severe employment losses.Manufacturing industries ; Employment ; Labor market ; Employees, Training of

Housing outcomes: an assessment of long-term trends

This paper was presented at the conference "Unequal incomes, unequal outcomes? Economic inequality and measures of well-being" as part of session 2, " Affordability of housing for young and poor families." The conference was held at the Federal Reserve Bank of New York on May 7, 1999. The authors examine trends in housing outcomes by income group. Orr and Peach indicate that there has been a substantial improvement in the physical adequacy of the housing stock over the past few decades, particularly for households in the lowest income quintile. Neighborhood quality for all income groups has also improved, although sharp differences in quality continue to exist across the groups. In one important respect, however, lower income households are worse off than before - housing costs now absorb a larger share of their income.Housing ; Housing - Finance

Harmonic analysis of lossy piezoelectric composite transducers using the plane wave expansion method

Periodic composite ultrasonic transducers oer many advantages but the periodic pillar architecture can give rise to unwanted modes of vibration which interfere with the piston like motion of the fundamental thickness mode. In this paper, viscoelastic loss is incorporated into a three dimensional plane wave expansion model (PWE) of these transducers. A comparison with experimental and nite element data is conducted and a design to damp out these lateral modes is investigated. Scaling and regularisation techniques are introduced to the PWE method to reduceill-conditioning in the large matrices which can arise. The identication of the modes of vibration is aided by examining proles of the displacements, electrical potentialand Poynting vector. The dispersive behaviour of a 2-2 composite transducer with high shear attenuation in the passive phase is examined. The model shows thatthe use of a high shear attenuation ller material improves the frequency band gap surrounding the fundamental thickness mode

Transformation of power means and a new class of means

AbstractUsing transformations associated with power means, a new class of means is defined. The behavior of these means is examined vis-à-vis power means, as a free parameter is varied. In particular, limits which contain those of J. L. Brenner (Pi Mu Epsilon J. 8(1985), 160–163) and L. Hoehn and I. Niven (Math. Mag. 58 (1985), 151–156) are obtained

A Comparison of Assessment Practices Between General and Special Education Teachers

The purpose of this study was to determine (a) the types of assessment formats that are being used in classrooms today,; (b) if a significant difference exists between general education and special education teachers\u27 choices of assessment formats,; and, (c) if teachers\u27 assessment training background correlated with the number or type of assessment formats chosen. One hundred thirty two middle school general and special education teachers from the state of Virginia were surveyed with a 22-item survey to determine how often each teacher used certain assessment formats in their classrooms. Results showed that these teachers use a variety of assessment formats within their classrooms . However, the amount of training in assessment did not correlate with the number or types of assessment formats the teachers used. Although no significant difference was found between the five different categories of assessment formats and the type of teacher who uses them, a weak positive correlation was found between the use of a processed-focused assessment format and the amount of assessment training a teacher has receive

Combined GMSK Communications and PN Ranging

A document discusses a method by which GMSK (Gaussian minimum shift keying) modulation and a pseudonoise (PN) ranging signal may be combined. By isolating the in-phase and quadrature components after carrier lock, and extracting their low-pass and band-pass filtered components, there is enough information available to both demodulate data and track the PN signal. The proposed combined GMSK communications and PN ranging is one potential approach to address emerging requirements for simultaneous high data rate communications from and tracking of vehicles in deep space or at the Moon