32,768 research outputs found
Dilemmas of Political Correctness
Debates about political correctness often proceed as if proponents see nothing to fear in erecting norms that inhibit expression on the one side, and opponents see nothing but misguided efforts to silence political enemies on the other.1 Both views are mistaken. Political correctness, as I argue, is an important attempt to advance the
legitimate interests of certain groups in the public sphere. However, this type of norm comes with costs that mustn’t be neglected–sometimes in the form of conflict with other values we hold dear, but often by creating an internal schism that threatens us with collective irrationality. Political correctness thus sets up dilemmas I wish to set out (but not, alas, resolve). The cliché is that political correctness tramples on rights to free-speech, as if the potential loss were merely expressive; the real issue is that in filtering public discourse, political correctness may defeat our own substantive aims
Graphs, permutations and topological groups
Various connections between the theory of permutation groups and the theory
of topological groups are described. These connections are applied in
permutation group theory and in the structure theory of topological groups.
The first draft of these notes was written for lectures at the conference
Totally disconnected groups, graphs and geometry in Blaubeuren, Germany, 2007.Comment: 39 pages (The statement of Krophollers conjecture (item 4.30) has
been corrected
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Attitudes to and perceptions of research
Ambivalences and uncertainties towards research are common amongst practitioners in counselling and psychotherapy. The chapter speaks directly to these concerns and suspicions and encourages the reader to reflect on their images of and fantasies about research. It discusses the role of research in our culture/society and the ways research is used in counselling and psychotherapy. It also looks at the range of social, personal and professional meanings that are associated with research, and possible reactions of research participants (clients, therapists) when asked to participate in research. Experiential and reflexive questions/exercises are utilized to engage the reader and reinforce their learning. By providing a broader perspective, the chapter helps to de-mystify counselling and psychotherapy research and to demonstrate the potential and challenges of research for practice and training
A Method to Calculate Fission-Fragment Yields versus Proton and Neutron Number in the Brownian Shape-Motion Model. Application to calculations of U and Pu charge yields
We propose a method to calculate the two-dimensional (2D) fission-fragment
yield versus both proton and neutron number, with inclusion of
odd-even staggering effects in both variables. The approach is to use Brownian
shape-motion on a macroscopic-microscopic potential-energy surface which, for a
particular compound system is calculated versus four shape variables:
elongation (quadrupole moment ), neck , left nascent fragment
spheroidal deformation , right nascent fragment deformation
and two asymmetry variables, namely proton and neutron
numbers in each of the two fragments. The extension of previous models 1)
introduces a method to calculate this generalized potential-energy function and
2) allows the correlated transfer of nucleon pairs in one step, in addition to
sequential transfer. In the previous version the potential energy was
calculated as a function of and of the compound system and its shape,
including the asymmetry of the shape. We outline here how to generalize the
model from the "compound-system" model to a model where the emerging fragment
proton and neutron numbers also enter, over and above the compound system
composition
HVAC system size – getting it right
There is evidence that many heating, ventilating & air conditioning (HVAC) systems, installed
in larger buildings, have more capacity than is ever required to keep the occupants
comfortable. This paper explores the reasons why this can occur, by examining a typical
brief/design/documentation process.
Over-sized HVAC systems cost more to install and operate and may not be able to control
thermal comfort as well as a “right-sized” system. These impacts are evaluated, where data
exists.
Finally, some suggestions are developed to minimise both the extent of, and the negative
impacts of, HVAC system over-sizing, for example:
• Challenge “rules of thumb” and/or brief requirements which may be out of date.
• Conduct an accurate load estimate, using AIRAH design data, specific to project
location, and then resist the temptation to apply “safety factors
• Use a load estimation program that accounts for thermal storage and diversification
of peak loads for each zone and air handling system.
• Select chiller sizes and staged or variable speed pumps and fans to ensure good part
load performance.
• Allow for unknown future tenancies by designing flexibility into the system, not by
over-sizing. For example, generous sizing of distribution pipework and ductwork will
allow available capacity to be redistributed.
• Provide an auxiliary tenant condenser water loop to handle high load areas.
• Consider using an Integrated Design Process, build an integrated load and energy
use simulation model and test different operational scenarios
• Use comprehensive Life Cycle Cost analysis for selection of the most optimal design
solutions.
This paper is an interim report on the findings of CRC-CI project 2002-051-B, Right-Sizing
HVAC Systems, which is due for completion in January 2006
Brownian shape motion on five-dimensional potential-energy surfaces: Nuclear fission-fragment mass distributions
Although nuclear fission can be understood qualitatively as an evolution of
the nuclear shape, a quantitative description has proven to be very elusive. In
particular, until now, there exists no model with demonstrated predictive power
for the fission fragment mass yields. Exploiting the expected strongly damped
character of nuclear dynamics, we treat the nuclear shape evolution in analogy
with Brownian motion and perform random walks on five-dimensional fission
potential-energy surfaces which were calculated previously and are the most
comprehensive available. Test applications give good reproduction of highly
variable experimental mass yields. This novel general approach requires only a
single new global parameter, namely the critical neck size at which the mass
split is frozen in, and the results are remarkably insensitive to its specific
value.Comment: 4 pages, 2 ps figure
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