1,776 research outputs found
Advancement of Data Quality Within the Adverse Condition Awareness Tool
The Adverse Condition Awareness Tool (ACAT) promotes search capability and discovery of software-related adverse conditions across NASA missions
Simulation of spacecraft attitude dynamics using TREETOPS and model-specific computer Codes
The simulation of spacecraft attitude dynamics and control using the generic, multi-body code called TREETOPS and other codes written especially to simulate particular systems is discussed. Differences in the methods used to derive equations of motion--Kane's method for TREETOPS and the Lagrangian and Newton-Euler methods, respectively, for the other two codes--are considered. Simulation results from the TREETOPS code are compared with those from the other two codes for two example systems. One system is a chain of rigid bodies; the other consists of two rigid bodies attached to a flexible base body. Since the computer codes were developed independently, consistent results serve as a verification of the correctness of all the programs. Differences in the results are discussed. Results for the two-rigid-body, one-flexible-body system are useful also as information on multi-body, flexible, pointing payload dynamics
A comparison of A-level performance in economics and business studies: how much more difficult is economics?
This paper uses ALIS data to compare academic performance in two subjects often viewed as relatively close substitutes for one another at A-level. The important role of GCSE achievement is confirmed for both subjects. There is evidence of strong gender effects and variation in outcomes across Examination Boards. A counterfactual exercise suggests that if the sample of Business Studies candidates had studied Economics nearly 40% of those who obtained a grade C or better in the former subject would not have done so in the latter. The opposite exercise uggests that 12% more Economics candidates would have achieved a grade C or better if they had taken Business Studies. In order to render a Business Studies A-level grade comparable to an Economics one in terms of relative difficulty, we estimate that a downward adjustment of 1.5 UCAS points should be applied to the former subject. This adjustment is lower than that suggested by correction factors based on conventional subject pair analysis for these two subjects
Assessing Vulnerability of Selected Sectors Under Environmental Tax Reform: The Issue of Pricing Power. ESRI WP222. October 2007
This paper investigates pricing power, an important criterion for identifying sectors that would be vulnerable under environmental tax reform. Environmental tax reform, defined here as introduction of carbon taxes alongside reductions in labour taxes, could bear heavily on sectors that are energy intensive and highly traded, in particular if their options for adapting technology are limited. However, a sector with pricing power has less to fear as, rather than having to conform to the world price, it can set its price to accommodate a tax mark-up
W. S. Merwin: 02-29-1968
Merwin discusses his changing poetic style, saying that he never stays excited about any style for very long, and that he now wants to write about direct experiences. He talks about the gradual abandonment of punctuation in his poems and the reliance on the language of a poem that a lack of punctuation highlights. Merwin also talks about the inability to shut the politics of the day out of his poems, and the mutual revulsion between art and topicality.https://digitalcommons.brockport.edu/writers_videos/1031/thumbnail.jp
Making Economic Time-Series Available to Users of Micro-Computers in Ireland. Quarterly Economic Commentary Special Article, October 1987
The major raw material used by economists who engage in applied research
or analysis is the vast range of economic time-series which are published by
many different bodies in all developed countries. The very range of sources
and definitions gives rise to many problems before any consideration is given
to matters of economic theory. "Datagrubbing" has traditionally taken a major
part of the time devoted to any individual research project. With many
economists engaging in overlapping areas of research and analysis there has
been considerable duplication of effort in the past in developing suitable sets
of data. Even if the producers of the raw material, economic time-series, do
not see it as their duty to produce consistent data in suitable machine readable
formats ( can be read by a computer directly without retyping) covering a
reasonable span of years, there is clearly an advantage to economists in cooperating
in this onerous task.
This article examines the range of economic time-series which are available
in computer databases or databanks in Ireland and considers how best these
data can be made available to users of micro-computers. Section 2 of the paper
sets out the background to the development of these databases and Section 3
describes their current scope and contents. Section 4 discusses the future
development of databases. Section 5 examines some technical considerations
on how best to access these data and Section 6 presents proposals as to how
these data, currently only available on one mainframe computer, could best be
made available to users of micro-computers in Ireland
Effect of ion mass on the evolution of extended defects during annealing of MeV ion-implanted p-type Si
Evolution of extended defects during annealing of MeV ion-implanted p-type Si has been characterized using deep level transient spectroscopy and transmission electron microscopy. The p-type Si was implanted with Si, Ge, and Sn ions with varying energies and doses from 5Ă10š² to 1Ă10šâ´âcmâťÂ˛ then annealed at 800â°C for 15 min. For all implanted species, the critical dose for transformation from point to extended defects has been determined. The type of extended defects formed depends upon the mass of the implanted species even though the dose was adjusted to create a similar damage distribution for all implanted species.Australian Research Council supported J. W. L
A solid-state process for formation of boron nitride nanotubes
The formation of boron nitride (BN) nanotubes via a solid-state process is demonstrated. The nanotubes are produced by first ball-milling hexagonal BN powder to generate highly disordered or amorphous nanostructures, followed by annealing at temperatures up to 1300â°C. The annealing leads to the nucleation and growth of hexagonal BN nanotubes of both cylindrical and bamboo-like morphology. Unlike previous mechanisms for nanotube formation, the reordering and solid-state growth process of our nanotubes does not involve deposition from the vapor phase nor chemical reaction
ENVIRONMENTAL ACCOUNTS: TIME SERIES + ECO-TAXES
This study was commissioned by the European Commission in cooperation with Eurostat with the
objective of improving and extending the scope of the environmental accounts for Ireland. It follows
two previous studies, Pilot Environmental Accounts published by the Central Statistics Office and the
Satellite Environmental Accounts for Ireland 1996, unpublished report to Eurostat (2000). As indicated
in the title, this study presents time series, which in some cases are of considerable length, and provides
information on what could loosely be called eco-taxes. Additionally, where feasible the study relates
environmental information to the underlying economic magnitudes and movements, and broadens the
information considerably.
The report consists of three self-contained sections. The sections cover (1) emissions to air, (2)
discharges to water and (3) disposals of solid waste and these three types of releases to the environment
are disaggregated according to NACE Rev 1 by five major economic sectors:
Agriculture/forestry/fishing
Energy transformation
Industry
Transport
Services
Households
though in some areas the breakdown is unavoidably less detailed and it is more detailed in others.
Section 1 on emissions to air concentrates on greenhouse gases and on improving the underlying
information on energy use. Behavioural analyses have been hampered in the past by inadequate time-series
of energy-related prices and taxes so that a large effort was devoted here to presenting coherent
time-series of these items
The Effects of Single-Wall Carbon Nanotubes on the Shear Piezoelectricity of Biopolymers
Shear piezoelectricity was investigated in a series of composites consisting of increased loadings of single-wall carbon nanotubes (SWCNTs) in poly (gamma-benzyl-L-glutamate), or PBLG. The effects of the SWCNTs on this material property in PBLG will be discussed. Their influence on the morphology of the polymer (degree of orientation and crystallinity), and electrical and dielectric properties of the composite will be reporte
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