Pathways to Accountability II

This report summarises the results of the 2009-2010 review process on the One World Trust Global Accountability Framework and the piloting of the draft framework during 2011, and presents the full One World Trust Pathways to Accountability II indicator framework. Our work in this field work is motivated by a concern about the persisting weakness and insufficient effectiveness of global organisations from all sectors in responding to the challenge of delivering global public goods to citizens and communities, the very people whom they claim to serve and benefit, and who are most often dependent on them

A Danish Profiling System

We describe the statistical model used for profiling new unemployed workers in Denmark. When a worker - during his or her first six months in unemployment - enters the employment office for the first time, this model predicts whether he or she will be unemployed for more than six months from that date or not. The case workers’ assessment of how to treat the person is partially based upon this prediction.unemployment duration; profiling

Slowly-growing gap-opening planets trigger weaker vortices

The presence of a giant planet in a low-viscosity disc can create a gap edge in the disc's radial density profile sharp enough to excite the Rossby Wave Instability. This instability may evolve into dust-trapping vortices that might explain the "banana-shaped" features in recently observed asymmetric transition discs with inner cavities. Previous hydrodynamical simulations of planet-induced vortices have neglected the timescale of hundreds to thousands of orbits to grow a massive planet to Jupiter-size. In this work, we study the effect of a giant planet's runaway growth timescale on the lifetime and characteristics of the resulting vortex. For two different planet masses (1 and 5 Jupiter masses) and two different disc viscosities ($\alpha$=3$\times 10^{-4}$ and 3$\times10^{-5}$), we compare the vortices induced by planets with several different growth timescales between 10 and 4000 planet orbits. In general, we find that slowly-growing planets create significantly weaker vortices with lifetimes and surface densities reduced by more than $50\%$. For the higher disc viscosity, the longest growth timescales in our study inhibit vortex formation altogether. Additionally, slowly-growing planets produce vortices that are up to twice as elongated, with azimuthal extents well above $180^{\circ}$ in some cases. These unique, elongated vortices likely create a distinct signature in the dust observations that differentiates them from the more concentrated vortices that correspond to planets with faster growth timescales. Lastly, we find that the low viscosities necessary for vortex formation likely prevent planets from growing quickly enough to trigger the instability in self-consistent models.Comment: 12 pages, 7 figures, Accepted by MNRA

Observational diagnostics of elongated planet-induced vortices with realistic planet formation timescales

Gap-opening planets can generate dust-trapping vortices that may explain some of the latest discoveries of high-contrast crescent-shaped dust asymmetries in transition discs. While planet-induced vortices were previously thought to have concentrated shapes, recent computational work has shown that these features naturally become much more elongated in the gas when simulations account for the relatively long timescale over which planets accrete their mass. In this work, we conduct two-fluid hydrodynamical simulations of vortices induced by slowly-growing Jupiter-mass planets in discs with very low viscosity ($\alpha = 3 \times 10^{-5}$). We simulate the dust dynamics for four particle sizes spanning 0.3 mm to 1 cm in order to produce synthetic ALMA images. In our simulations, we find that an elongated vortex still traps dust, but not directly at its center. With a flatter pressure bump and disruptions from the planet's overlapping spiral density waves, the dust instead circulates around the vortex. This motion (1) typically carries the peak off-center, (2) spreads the dust out over a wider azimuthal extent $\geq 180^{\circ}$, (3) skews the azimuthal profile towards the front of the vortex, and (4) can also create double peaks in newly-formed vortices. In particular, we expect that the most defining observational signature, a peak offset of more than $30^{\circ}$, should be detectable $>30\%$ of the time in observations with a beam diameter of at most the planet's separation from its star.Comment: Accepted to MNRAS. 13 pages, 8 figures. Movies available at: https://lavinia.as.arizona.edu/~mhammer/vortex_signatures.htm

Dimensionality Reduction Mappings

A wealth of powerful dimensionality reduction methods has been established which can be used for data visualization and preprocessing. These are accompanied by formal evaluation schemes, which allow a quantitative evaluation along general principles and which even lead to further visualization schemes based on these objectives. Most methods, however, provide a mapping of a priorly given finite set of points only, requiring additional steps for out-of-sample extensions. We propose a general view on dimensionality reduction based on the concept of cost functions, and, based on this general principle, extend dimensionality reduction to explicit mappings of the data manifold. This offers simple out-of-sample extensions. Further, it opens a way towards a theory of data visualization taking the perspective of its generalization ability to new data points. We demonstrate the approach based on a simple global linear mapping as well as prototype-based local linear mappings.

Chapter 5 The Communicative Constitution of the World

This chapter introduces Niklas Luhmann’s theory of organizations, which he conceived as communicatively constituted social systems that are created through decision-making. Decisions are thereby also understood as communicative events, ones that are inherently paradoxical as they attempt to select a certain option while simultaneously communicating discarded alternatives. Decisions are, hence, fragile events provoking opposition and rejection. Organizations can be understood as social phenomena that are capable of de-paradoxifying decisions by featuring these very decisions as their main mode of operation. However, Luhmann asserts that not only organizations, but our entire social world is constituted through communication. Against this backdrop, this chapter also highlights the role of macro-societal domains such as politics, science, economics, and love. Like organizations, these macro-societal domains can be understood as communicatively constituted systems that have certain characteristics and effects. In this respect, the Luhmannian framework offers a communication-based counterprogram to the mainstream debates of institutionalism