117,841 research outputs found
Kozai-Lidov cycles towards the limit of circumbinary planets
In this paper we answer a simple question: can a misaligned circumbinary
planet induce Kozai-Lidov cycles on an inner stellar binary? We use known
analytic equations to analyse the behaviour of the Kozai-Lidov effect as the
outer mass is made small. We demonstrate a significant departure from the
traditional symmetry, critical angles and amplitude of the effect. Aside from
massive planets on near-polar orbits, circumbinary planetary systems are devoid
of Kozai-Lidov cycles. This has positive implications for the existence of
highly misaligned circumbinary planets: an observationally unexplored and
theoretically important parameter space.Comment: Accepted for publication in MNRAS Letters. 5 page
Electromagnetic properties of baryons
We discuss the chiral behavior of nucleon and Delta(1232) electromagnetic
properties within the framework of a SU(2) covariant baryon chiral perturbation
theory. Our one-loop calculation is complete to the order p^3 and p^4/Delta
with Delta as the Delta(1232)-nucleon energy gap. We show that the magnetic
moment of a resonance can be defined through the linear energy shift only when
an additional relation between the involved masses and the applied magnetic
field strength is fulfilled. Singularities and cusps in the pion mass
dependence of the Delta(1232) electromagnetic moments reflect a
non-fulfillment. We show results for the pion mass dependence of the nucleon
iso-vector electromagnetic quantities and present results for finite volume
effects on the iso-vector anomalous magnetic moment.Comment: 4 pages, 3 figures, prepared for Proceedings of the International
Conference on the Structure of Baryons (BARYONS'10), Osaka, Japan, Dec. 7-11,
201
Comparison of a linear and a nonlinear washout for motion simulators utilizing objective and subjective data from CTOL transport landing approaches
Objective and subjective data gathered in the processes of comparing a linear and a nonlinear washout for motion simulators reveal that there is no difference in the pilot performance measurements used during instrument landing system (ILS) approaches with a Boeing 737 conventional takeoff and landing (CTOL) airplane between fixed base, linear washout, and nonlinear washout operations. However, the subjective opinions of the pilots reveal an important advance in motion cue presentation. The advance is not in the increased cue available over a linear filter for the same amount of motion base travel but rather in the elimination of false rotational rate cues presented by linear filters
Evaluation of a linear washout for simulator motion cue presentation during landing approach
The comparison of a fixed-base versus a five-degree-of-freedom motion base simulation of a 737 conventional take-off and landing (CTOL) aircraft performing instrument landing system (ILS) landing approaches was used to evaluate a linear motion washout technique. The fact that the pilots felt that the addition of motion increased the pilot workload and this increase was not reflected in the objective data results, indicates that motion cues, as presented, are not a contributing factor to root-mean-square (rms) performance during the landing approach task. Subjective results from standard maneuvering about straight-and-level flight for specific motion cue evaluation revealed that the longitudinal channels (pitch and surge) possibly the yaw channel produce acceptable motions. The roll cue representation, involving both roll and sway channels, was found to be inadequate for large roll inputs, as used for example, in turn entries
Three-loop corrections to the lightest Higgs scalar boson mass in supersymmetry
I evaluate the largest three-loop corrections to the mass of the lightest
Higgs scalar boson in the Minimal Supersymmetric Standard Model in a
mass-independent renormalization scheme, using effective field theory and
renormalization group methods. The contributions found here are those that
depend only on strong and Yukawa interactions and on the leading and
next-to-leading logarithms of the ratio of a typical superpartner mass scale to
the top quark mass. The approximation assumes that all superpartners and the
other Higgs bosons can be treated as much heavier than the top quark, but does
not assume their degeneracy. I also discuss the consistent addition of the
three-loop corrections to a complete two-loop calculation.Comment: 9 page
A Conformal Mapping and Isothermal Perfect Fluid Model
Instead of conformal to flat spacetime, we take the metric conformal to a
spacetime which can be thought of as ``minimally'' curved in the sense that
free particles experience no gravitational force yet it has non-zero curvature.
The base spacetime can be written in the Kerr-Schild form in spherical polar
coordinates. The conformal metric then admits the unique three parameter family
of perfect fluid solution which is static and inhomogeneous. The density and
pressure fall off in the curvature radial coordinates as for
unbounded cosmological model with a barotropic equation of state. This is the
characteristic of isothermal fluid. We thus have an ansatz for isothermal
perfect fluid model. The solution can also represent bounded fluid spheres.Comment: 10 pages, TeX versio
Towards an expanded model of litigation
Introduction: The call for contributions for this workshop describes the important new challenges for the legal search
community this domain brings. Rather than just understanding the challenges this domain poses in terms of
their technical properties, we would like to suggest that understanding these challenges as socio-technical
challenges will be important. That is, as well as calling for research on a technical level to address these
challenges we are also calling for work to understand the social practices of those involved in e-discovery
(ED) and related legal work. A particularly interesting feature of this field is that it is likely that search
technologies will (at least semi-)automate responsiveness review in the relatively near term and this will
change the way that the work is organised and done in many ways – offering new possibilities for new
ways of organising the work. As well as designing those technologies for automating responsiveness
review we need to be envisioning how the work will be done in the future, how these technologies will
impact the organisation of the case and so on. In this position paper we therefore outline the importance of
understanding the wider social context of ED when designing tools and technologies to support and change
the work. We would like to reinforce and expand on Conrad’s call for IR researchers to understand just
what ED entails [2], include the stages that come both before and after core retrieval activities.
The importance of considering the social aspects of work in the design of the technology has been
established for some time. Ushering in this ‘turn to the social,’ and focusing on interface design, Gentner
and Grudin [4] described how the GUI has already changed from an interface for engineers, representing
the engineering model of the machine to one that supported single ‘everyman’ users (based on ideas from
psychology). From then onwards the interface has evolved to support groups of users, taking into account
the social and organisational contexts of use. This has particular resonance for the design of ED
technologies: during ED in particular and the wider legal process there are often many lawyers involved –
reviewing documents, determining issues, etc. Even if the way that their work is organised currently is not
seen as collaborative in the traditional sense – with individual lawyers working on individual document sets
to review them - their work needs to be coordinated and it seems likely that their work could be enhanced
by, for example, knowledge of what their colleagues had found, how the case was shaping up, new key
terms and facts turned up and so on. Work is often modelled for the purposes of design using process
models, but this misses out on the richness and variety actually found when one examines how the work is
carried out [3]. Technologies which strictly enforce the process models can often hinder the work, or end
up being worked around as was the case with workflow systems since people interpret processes very
flexibly to get the work done ([1], [3]). Other studies in other fields have found similar problems when
systems are designed on for example cognitive models of how the work is done; they often do not take into
account the situated nature of the work and thus they can be very difficult to use [5]. We believe, like [2],
that a clear understanding of the social practices of ED is vital for the creation of high-quality, meaningful
tools and technologies. We furthermore propose that work practice studies, to be used in combination with
other methods, are a central part of getting the detailed understanding of the work practices central to
designing useful and intelligent tools. Work practice studies would involve ethnographies, consisting
primarily of observation, undertaken of practitioners engaging in the work of ED
Shareholder Voting and Directors’ Remuneration Report Legislation: Say on Pay in the U.K. (CRI 2009-004)
This paper investigates shareholder voting in the UK. The Directors’ Remuneration Report (DRR) Regulations of 2002 gave shareholders a mandatory non-binding vote on boardroom pay. First, using data on about 50,000 resolutions over the period 2002 to 2007 we find that less than 10% of shareholders abstain or vote against the mandated Directors’ Remuneration Report (DRR) resolution. Second, investors are more likely to vote against DRR resolutions compared to non-pay resolutions. Third, shareholders are more likely to vote against general executive pay resolutions, such as stock options, long term incentive plans and bonus resolutions compared to non-pay resolutions. Forth, firms with higher CEO pay attract greater voting dissent. Fifth, there is little evidence that CEO pay is lower in firms that previously experienced high levels of shareholder dissent. In addition, there is little evidence that the equity pay-mix, representing better owner-manager alignment, is greater in such firms. Currently, we find limited evidence that, on average, ‘say on pay’ materially alters the subsequent level and design of CEO compensation
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