15,839 research outputs found
Techno-mathematical literacies in the workplace: a critical skills gap
There has been a radical shift in the mathematical skills required in modern workplaces. With the ubiquity of IT, employees now require Techno-mathematical Literacies, the mastery of new kinds of mathematical knowledge shaped by the systems that govern their work. The education system does not fully recognise these skills, employees often lack them, and companies struggle to improve them. This project has developed prototype learning resources to train a variety of employees in the mathematical awareness and knowledge that today’s employment require
Understanding How Reverse Engineers Make Sense of Programs from Assembly Language Representations
This dissertation develops a theory of the conceptual and procedural aspects involved with how reverse engineers make sense of executable programs. Software reverse engineering is a complex set of tasks which require a person to understand the structure and functionality of a program from its assembly language representation, typically without having access to the program\u27s source code. This dissertation describes the reverse engineering process as a type of sensemaking, in which a person combines reasoning and information foraging behaviors to develop a mental model of the program. The structure of knowledge elements used in making sense of executable programs are elicited from a case study, interviews with subject matter experts, and observational studies with software reverse engineers. The results from this research can be used to improve reverse engineering tools, to develop training requirements for reverse engineers, and to develop robust computational models of human comprehension in complex tasks where sensemaking is required
Observation of the Final Boundary Condition: Extragalactic Background Radiation and the Time symmetry of the Universe
This paper examines an observable consequence for the diffuse extragalactic
background radiation (EGBR) of the hypothesis that if closed, our universe
possesses time symmetric boundary conditions. For simplicity, attention is
focused on optical wavelengths. The universe is modeled as closed Friedmann-
Roberston-Walker. It is shown that, over a wide range of frequencies,
electromagnetic radiation can propagate largely unabsorbed from the present
epoch into the recollapsing phase, confirming and demonstrating the generality
of results of Davies and Twamley. As a consequence, time symmetric boundary
conditions imply that the optical EGBR is at least twice that due to the
galaxies on our past light cone, and possibly considerably more. It is
therefore possible to test experimentally the notion that if our universe is
closed, it may be in a certain sense time symmetric. The lower bound on the
"excess" EGBR in a time symmetric universe is consistent with present
observations. Nevertheless, better observations and modelling may soon rule it
out entirely. In addition, many physical complications arise in attempting to
reconcile a transparent future light cone with time symmetric boundary
conditions, thereby providing further arguments against the possibility that
our universe is time symmetric.Comment: latex 2.09, 30 pages, 1 figure. Figure added, errors corrected.
Slight revision of published versio
Risk across design domains
Design processes involve risk: to life and limb if the product is unsafe, to the financial health of the company if the product is late, unsuccessful or simply the wrong product, as well as to the emotions and careers of the designers. Many of the risks are shared universally by all designers, but each different industry and each different project faces its own spectrum of serious and minor risks. Different industries have put their methodological effort into finding ways to mitigate the risks they recognise as important. As part of the Across Design project exploring similarities and differences between design processes in different industries, this paper examines how risks are perceived and handled in different types of design process, and proposes that designers and managers can usefully look to other industries for ways to handle risks that are more central for those other industries
The Environmental Dependence of the Evolving S0 Fraction
We reinvestigate the dramatic rise in the S0 fraction, f_S0, within clusters
since z ~ 0.5. In particular, we focus on the role of the global galaxy
environment on f_S0 by compiling, either from our own observations or the
literature, robust line-of-sight velocity dispersions, sigma's, for a sample of
galaxy groups and clusters at 0.1 < z < 0.8 that have uniformly determined,
published morphological fractions. We find that the trend of f_S0 with redshift
is twice as strong for sigma < 750 km/s groups/poor clusters than for
higher-sigma, rich clusters. From this result, we infer that over this redshift
range galaxy-galaxy interactions, which are more effective in lower-sigma
environments, are more responsible for transforming spiral galaxies into S0's
than galaxy-environment processes, which are more effective in higher-sigma
environments. The rapid, recent growth of the S0 population in groups and poor
clusters implies that large numbers of progenitors exist in low-sigma systems
at modest redshifts (~ 0.5), where morphologies and internal kinematics are
within the measurement range of current technology.Comment: Accepted for publication in The Astrophysical Journal. 13 pages, 6
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