Robust Deviations from Signaling Equilibria

In Sender-Receiver games with costly signaling, some equilibria are vulnerable to deviations which could be "unambiguously" interpreted by the Receiver as coming from a unique set of possible Sender-types. The vulnerability occurs when the types in this set are the ones who gain from the deviation, regardless of the posterior beliefs the Receiver forms over that set. We formalize this idea and use it to characterize a unique equilibrium outcome in two classes of games. First, in mono- tonic signaling games, only the Riley outcome is immune to this sort of deviation. Our result therefore provides a plausible story behind the selection made by Cho and Kreps' (1987) D1 criterion on this class of games. Second, we examine a version of Crawford and Sobel's (1982) model but with costly signaling and finite type sets, where standard refinements have no effect. We show that only a Riley-like separating equilibrium is immune to these deviations.Signaling games, Sender-Receiver, robust equilibrium, re¯nements.

The Price of Advice

We develop a model of consulting (advising) where the role of the consultant is that she can reveal signals to her client which refine the client’s original private estimate of the profitability of a project. Importantly, only the client can observe or evaluate these signals, the consultant cannot. We characterize the optimal contract between the consultant and her client. It is a menu consisting of pairs of transfers specifying payments between the two parties (from the client to the consultant or vice versa) in case the project is undertaken by the client and in case it is not. The main result of the paper is that in the optimal mechanism, the consultant obtains the same profit as if she could evaluate the impact of the signals (whose release she controls) on the client’s profit estimate.Mechanism Design, Information Disclosure, Consulting, Advising

Photometric Redshifts for Galaxies in the GOODS Southern Field

We use extensive multi-wavelength photometric data from the Great Observatories Origins Deep Survey (GOODS) to estimate photometric redshifts for a sample of 434 galaxies with spectroscopic redshifts in the Chandra Deep Field South. Using the Bayesian method, which incorporates redshift/magnitude priors, we estimate photometric redshifts for galaxies in the range 18 < R (AB) < 25.5, giving an rms scatter of 0.11. The outlier fraction is < 10%, with the outlier-clipped rms being 0.047. We examine the accuracy of photometric redshifts for several, special sub--classes of objects. The results for extremely red objects are more accurate than those for the sample as a whole, with rms of 0.051 and very few outliers (3%). Photometric redshifts for active galaxies, identified from their X-ray emission, have a dispersion of 0.104, with 10% outlier fraction, similar to that for normal galaxies. Employing a redshift/magnitude prior in this process seems to be crucial in improving the agreement between photometric and spectroscopic redshifts.Comment: Accepted for publication in ApJ

Cool Stars and Space Weather

Stellar flares, winds and coronal mass ejections form the space weather. They are signatures of the magnetic activity of cool stars and, since activity varies with age, mass and rotation, the space weather that extra-solar planets experience can be very different from the one encountered by the solar system planets. How do stellar activity and magnetism influence the space weather of exoplanets orbiting main-sequence stars? How do the environments surrounding exoplanets differ from those around the planets in our own solar system? How can the detailed knowledge acquired by the solar system community be applied in exoplanetary systems? How does space weather affect habitability? These were questions that were addressed in the splinter session "Cool stars and Space Weather", that took place on 9 Jun 2014, during the Cool Stars 18 meeting. In this paper, we present a summary of the contributions made to this session.Comment: Proceedings of the 18th Cambridge Workshop on Cool Stars, Stellar Systems, and the Sun, Eds G. van Belle & H. Harris, 13 pages, 1 figur

Identifikasi Antropogenik Pencemaran Tanah oleh Sampah Domestik

Abstrak :Telah dilakukan penelitian tentang antropogenik pencemaran tanah dengan menganalisis kandungan logam berat tanah pada tumpukan sampah  di sekitar pemukiman tepatnya di jalan Chairil Anwar, Kecamatan Wua-Wua, Kota Kendari. Sampel tanah di gali menggunakan bor tanah dengan kedalaman 0 sampai 90 cm  yang seterusnya dihaluskan dan diayak dengan ayakan 200 mess. Sampel tanah dianalisis dengan metode XRF (X-Ray Fluorescence) untuk mengidentifikasi kandungan logam berat di dalam tanah. Sementara itu, suseptibilitas magnetik tanah dianalisis dengan menggunakan susceptibilitiy meter Bartington MS2B untuk mengetahui sifat magnetiknya.   Hasil pengukuran menunjukkan bahwa tanah tersebut telah tercemar  unsur logam berat seperti  Besi, Mangan, Seng,  dan Chromium dengan persentase  yang jauh melebihi ambang batas yang seharusnya ada dalam tanah, sementara itu  kandungan unsur logam berat Pb (Timbal),  As (Arsenik) dan Cu (Tembaga) belum melampaui ambang batasnya. Berdasarkan hasil analisis sifat magnetik tanah sumber pencemaran tanah berasal dari antropogenik aktivitas manusia.Keywords: Antropogenik, pencemaran tanah, suseptibilitas magneti