31,148 research outputs found
How does Information Technology impact the methods, potential and purpose of education?
It is evident that information technology has affected changes to the methods, purpose and the perceived potential of education. While various authors differ in their opinion on the degree, desirability and destiny of these changes, all agree that change processes have certainly been underway. However, the process of change is far from over. Numerous authors auger grave peril for education institutions that refuse to integrate information technology into every level of the education institution. Some authors argue that the very nature of education itself will change. Information technology, whether perceived as a power for good or a power for evil, certainly has not been neutral. While effecting change has been difficult in many situations, contemporary information technology has by its very nature, been an agent of change in education institutions
Measuring Unemployment and Structural Unemployment
This paper surveys recent research on how to measure labour market activities such as unemployment and labour force participation. The conventional approach to distinguishing between unemployment and non-participation is to use a priori reasoning and self-reported survey responses about current activities, specifically availability for work and job search. In contrast, the research surveyed here employs evidence on the subsequent consequences of current activities, in particular on transitions among labour force states. This general approach appears to be a promising method for bringing evidence to bear on these difficult measurement issues.
Small Differences That Matter: Labor Markets and Income Maintenance in Canada and the United States
The Discovery and History of the Dalgaranga Meteorite Crater, Western Australia
The Dalgaranga meteorite crater, 100 km northeast of Yalgoo, Western
Australia, was one of the first impact structures identified in Australia, the
smallest isolated crater found in Australia, and the only confirmed crater in
the world associated with a mesosiderite projectile. 17 years passed before the
Dalgaranga meteorites were described in the scientific literature and nearly 40
years passed before a survey of the structure was published. The reasons for
the time-gap were never explained and a number of factual errors about the
discovery and early history remain uncorrected in the scientific literature.
Using historical and archival documents, and discussions with people involved
in Dalgaranga research, the reasons for this time gap are explained by a series
of minor misidentifications and coincidences. The age of the crater has yet to
be determined, but using published data, we estimate the projectile mass to be
500-1000 kg.Comment: Australian Journal of Earth Sciences, accepte
Economic Change and Worker Displacement in Canada: Consequences and Policy Responses
Change is an enduring feature of the economy and the labour market, even in normal times. The importance of adjusting to change, and of policies that promote adjustment, has been a recurring theme throughout David Dodge’s distinguished career. This paper deals with “displaced workers,†those who permanently lose their jobs because of changing economic circumstances. I examine what we know about displacement and its consequences, and assess policies designed to assist workers adversely affected by economic change. A central finding of research on displacement is that long tenure displaced workers -- those who have held their jobs for an extended period of time -- suffer much more from losing their jobs than do others. Canada’s Employment Insurance does not take into account this salient feature of the consequences of job loss. The paper discusses ways of addressing this deficiency in our primary social insurance program for job losers.labour market adjustment, job displacement, unemployment, unemployment insurance, adjustment assistance policies, wage insurance
A Lazy Approach for Supporting Nested Transactions
Transactional memory (TM) is a compelling alternative to traditional synchronization, and implementing TM primitives directly in hardware offers a potential performance advantage over software-based methods. In this paper, we demonstrate that many of the actions associated with transaction abort and commit may be performed lazily -- that is, incrementally, and on demand. This technique is ideal for hardware, since it requires little space or work; in addition, it can improve performance by sparing accesses to committing or aborting locations from having to stall until the commit or abort completes.
We further show that our lazy abort and commit technique supports open nesting and orElse, two language-level proposals which rely on transactional nesting. We also provide design notes for supporting lazy abort and commit on our own hardware TM system, based on VTM
The Contribution of EUV from Clusters of Galaxies to the Cosmic Ionizing Background
Recent observations with the Extreme Ultraviolet Explorer (EUVE) suggest that
at least some clusters of galaxies are luminous sources of extreme ultraviolet
(EUV) radiation. It is not clear yet whether EUV emission is a general feature
of clusters; for the purposes of limiting the contribution to the background
radiation, we assume that it is true of most clusters. Assuming that the source
of the EUV emission is inverse Compton (IC) scattering of the Cosmic Microwave
Background photons by relativistic electrons, we construct a simple model for
the expected average emission from clusters as a function of their mass and the
redshift of interest. Press-Schechter theory is used to determine the abundance
of clusters of various masses as a function of redshift. We determine the
amount of background radiation produced by clusters. The total mean intensity,
spectrum, and the ionization rates for HI and HeII are determined at present
and at a variety of redshifts. Because clusters form by the merger of smaller
subclusters, the amount of EUV background radiation should be larger at present
than in the past. We compare our results to the ionizing background expected
from quasars. We find that while clusters do contribute a significant EUV
background, it is less than a percent of that expected from quasars.Comment: 13 pages in emulateapj5 style with 7 figures, accepted for
publication in Astrophysical Journa
Combining phase field crystal methods with a Cahn-Hilliard model for binary alloys
During phase transitions certain properties of a material change, such as
composition field and lattice-symmetry distortions. These changes are typically
coupled, and affect the microstructures that form in materials. Here, we
propose a 2D theoretical framework that couples a Cahn-Hilliard (CH) model
describing the composition field of a material system, with a phase field
crystal (PFC) model describing its underlying microscopic configurations. We
couple the two continuum models via coordinate transformation coefficients. We
introduce the transformation coefficients in the PFC method, to describe affine
lattice deformations. These transformation coefficients are modeled as
functions of the composition field. Using this coupled approach, we explore the
effects of coarse-grained lattice symmetry and distortions on a phase
transition process. In this paper, we demonstrate the working of the CH-PFC
model through three representative examples: First, we describe base cases with
hexagonal and square lattice symmetries for two composition fields. Next, we
illustrate how the CH-PFC method interpolates lattice symmetry across a diffuse
composition phase boundary. Finally, we compute a Cahn-Hilliard type of
diffusion and model the accompanying changes to lattice symmetry during a phase
transition process.Comment: 9 pages, 5 figure
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