218,130 research outputs found
Research-practice interactions as reported in recent design studies: Still promising, still hazy
This study portrays recent researchâpractice connections found in 18 design research reports focusing on the creation of instructional solutions. Solutions in different stages of development varied greatly in duration, ranging from one lesson to a whole year curriculum, spanned all levels of education, many subjects (science, math, language, culture, teacher education, etc.). Close collaboration between researchers and practitioners was prominent in all of the 18 projects studied. Participants in primary and secondary education projects have quite distinct roles regarding the teaching and researching, but they design their instruction solutions often collaboratively. Nearly all projects reported on how designed solutions were anchored in research, either from literature or from in-house project data. All articles indicated that research fed (re-)design, but few specified how. Based on our findings, we call for increased research and reporting on the specific strategies employed by design research participants to facilitate the production of new theoretical understanding through design of instructional solution
AI for the Common Good?! Pitfalls, challenges, and Ethics Pen-Testing
Recently, many AI researchers and practitioners have embarked on research
visions that involve doing AI for "Good". This is part of a general drive
towards infusing AI research and practice with ethical thinking. One frequent
theme in current ethical guidelines is the requirement that AI be good for all,
or: contribute to the Common Good. But what is the Common Good, and is it
enough to want to be good? Via four lead questions, I will illustrate
challenges and pitfalls when determining, from an AI point of view, what the
Common Good is and how it can be enhanced by AI. The questions are: What is the
problem / What is a problem?, Who defines the problem?, What is the role of
knowledge?, and What are important side effects and dynamics? The illustration
will use an example from the domain of "AI for Social Good", more specifically
"Data Science for Social Good". Even if the importance of these questions may
be known at an abstract level, they do not get asked sufficiently in practice,
as shown by an exploratory study of 99 contributions to recent conferences in
the field. Turning these challenges and pitfalls into a positive
recommendation, as a conclusion I will draw on another characteristic of
computer-science thinking and practice to make these impediments visible and
attenuate them: "attacks" as a method for improving design. This results in the
proposal of ethics pen-testing as a method for helping AI designs to better
contribute to the Common Good.Comment: to appear in Paladyn. Journal of Behavioral Robotics; accepted on
27-10-201
The Effective Electroweak Chiral Lagrangian: The Matter Sector
We parametrize in a model-independent way possible departures from the
minimal Standard Model predictions in the matter sector. We only assume the
symmetry breaking pattern of the Standard Model and that new particles are
sufficiently heavy so that the symmetry is non-linearly realized. Models with
dynamical symmetry breaking are generically of this type. We review in the
effective theory language to what extent the simplest models of dynamical
breaking are actually constrained and the assumptions going into the comparison
with experiment. Dynamical symmetry breaking models can be approximated at
intermediate energies by four-fermion operators. We present a complete
classification of the latter when new particles appear in the usual
representations of the group as well as a partial
classification in the general case. We discuss the accuracy of the four-fermion
description by matching to a simple `fundamental' theory. The coefficients of
the effective lagrangian in the matter sector for dynamical symmetry breaking
models (expressed in terms of the coefficients of the four-quark operators) are
then compared to those of models with elementary scalars (such as the minimal
Standard Model). Contrary to a somewhat widespread belief, we see that the sign
of the vertex corrections is not fixed in dynamical symmetry breaking models.
This work provides the theoretical tools required to analyze, in a rather
general setting, constraints on the matter sector of the Standard Model.Comment: Latex, 45 pages, 8 eps figures. Sections 5, 6 and 9 have been
rewritten to clarify the contents. Some mistakes and typos have been
corrected. Two references have been added. Figures 7 and 8 have been modifie
The Electroweak Chiral Lagrangian for the Standard Model with a Heavy Higgs
The most general chiral Lagrangian for electroweak interactions with the
complete set of invariant operators up to dimension four
is considered. The two-point and three-point functions with external gauge
fields are derived from this effective chiral Lagrangian to one-loop order in a
generic -gauge. The same set of Green's functions are paralelly studied
in the renormalizable standard model to one-loop order, in a -gauge and
in the large Higgs mass limit. An appropriate set of matching conditions
connecting the Green's functions of the two theories allows us to derive,
systematically, the values of the chiral Lagrangian coefficients corresponding
to the large Higgs mass limit of the standard model. These chiral parameters
represent the non-decoupling effects of a heavy Higgs particle and incorporate
both the leading logarithmic dependence on \mh and the next to leading
constant contributions. Some phenomenological implications are also discussed.Comment: pg.23, LaTeX, 3 figures (not included), FTUAM-93/2
Vector Meson Masses in Chiral Perturbation Theory
We discuss the vector meson masses within the context of Chiral Perturbation
Theory performing an expansion in terms of the momenta, quark masses and 1/Nc.
We extend the previous analysis to include isospin breaking effects and also
include up to order . We discuss vector meson chiral perturbation theory
in some detail and present a derivation from a relativistic lagrangian. The
unknown coefficients are estimated in various ways. We also discuss the
relevance of electromagnetic corrections and the implications of the present
calculation for the determination of quark masses.Comment: 17 pages, LaTeX, 2 figures. Revised version to appear in Nuclear
Physics B. One reference added, some misprints, mainly in the appendix,
correcte
- âŠ