Peaks and Troughs in Helioseismology: The Power Spectrum of Solar Oscillations

I present a matched-wave asymptotic analysis of the driving of solar oscillations by a general localised source. The analysis provides a simple mathematical description of the asymmetric peaks in the power spectrum in terms of the relative locations of eigenmodes and troughs in the spectral response. It is suggested that the difference in measured phase function between the modes and the troughs in the spectrum will provide a key diagnostic of the source of the oscillations. I also suggest a form for the asymmetric line profiles to be used in the fitting of solar power spectra. Finally I present a comparison between the numerical and asymptotic descriptions of the oscillations. The numerical results bear out the qualitative features suggested by the asymptotic analysis but suggest that numerical calculations of the locations of the troughs will be necessary for a quantitative comparison with the observations.Comment: 18 pages + 8 separate figures. To appear in Ap

Rail mega-projects in the realm of inter- and intra-city accessibility: evidence and outlooks for Berlin

This article summarizes and complements recent quantitative research on the impact of the Berlin railway system on the urban economy. Evidence suggests that access to intra-city rail lines has had a considerable impact on the value of urban land since at least the late nineteenth century. Since then, access to the intra-city rail network has remained a significant determinant of urban land value, although the marginal impact has decreased over time. In contrast, the post-unification realignment of Berlin's inter-city rail system has had, if any, only a weak impact on real estate markets. Micro-level simulations indicate that the new central station's connection to the urban railway network is likely to have more pronounced, although relatively localized impacts, raising the question of how to balance the cost for infrastructure among landlords and society

External productivity and utility effects of city airports

This paper uses a micro-level data set for residential and commercial property transactions to investigate external utility and productivity effects for three (city) airports in Berlin, Germany in a spatial hedonic analysis. We find strong evidence of adverse noise effects on property prices and a discontinuity at approximately 55dB. Marginal price effects decrease significantly in the presence of alternative noise sources, which can lead to biased estimates if the interaction effect is not accounted for appropriately. Given that there is less evidence of positive accessibility effects, our result questions the justification for locating airports in city centres

The train has left the station: Do markets value intra-city access to inter-city rail connections?

This paper analyzes the impact of access to inter-city rail connections on property prices using hedonic, difference-in-difference and time-difference estimation strategies. We investigate the reorganization of the rail system in post-unification Berlin, Germany, which provides much variation in accessibility. Evidence does not support the existence of localized effects. Neither in proximity to stations nor at city-level are there significant price adjustments. No significant price effect is revealed on distance to stations, even when allowing for a complementary relationship. An increase in the attractiveness of central locations coinciding with the final announcement of the train schedule is not attributable to the intervention.Property prices; transport innovation; inter-city connection; railroad; Berlin

Valuing iconic design: Frank Lloyd Wright architecture in Oak Park, Illinois

This study investigates the willingness of homebuyers to pay for co-location with iconic architecture. Oak Park, Illinois was chosen as the study area given its unique claim of having 24 residential structures designed by world-famous American architect Frank Lloyd Wright, in addition to dozens of other designated landmarks and three preservation districts. This study adds to the limited body of existing literature on the external price effects of architectural design and is unique in its focus on residential architecture. We find a premium of about 8.5% within 50-100m of the nearest Wright building and about 5% within 50-250m. These results indicate that an external premium to iconic architecture does exist, although it may partially be attributable to the prominence of the architec

Quantum Interest in (3+1) dimensional Minkowski space

The so-called "Quantum Inequalities", and the "Quantum Interest Conjecture", use quantum field theory to impose significant restrictions on the temporal distribution of the energy density measured by a time-like observer, potentially preventing the existence of exotic phenomena such as "Alcubierre warp-drives" or "traversable wormholes". Both the quantum inequalities and the quantum interest conjecture can be reduced to statements concerning the existence or non-existence of bound states for a certain one-dimensional quantum mechanical pseudo-Hamiltonian. Using this approach, we shall provide a simple proof of one version of the Quantum Interest Conjecture in (3+1) dimensional Minkowski space.Comment: V1: 8 pages, revtex4; V2: 10 pages, some technical changes in details of the argument, no change in physics conclusions, this version essentially identical to published versio

Shallow Surveying in Hazardous Waters

Of order one importance to any study of nearshore processes is knowledge of the bathymetry in shallow water. This is true for studies on open coast sandy beaches where surf zone dynamics drive the system, inlet environments where bathymetric evolution can rapidly change navigation channels, and in more benign, lower-energy coastal environments that evolve slowly over 10’s to 100’s of years. Difficulties in obtaining shallow bathymetry where depth-limited wave breaking occurs, submerged hazards are present, or other harsh environments has led to the development of survey systems on highly maneuverable personal watercraft (Beach, et al., 1994; Cote, 1999; Dugan, et al., 1999; MacMahan, 2001). In this work we discuss shallow water surveying from the Coastal Bathymetry Survey System (CBASS), a Yamaha Waverunner equipped with differential GPS, single-beam 192 KHz acoustic echo-sounder, and onboard navigation system. Data obtained with the CBASS in three regions will be discussed, including an energetic surf zone located in southern California during the 2003 Nearshore Canyon Experiment (NCEX), on Lake Erie in 2002 (and compared with historical surveys dating back 150 years), and around Piscataqua River Inlet, NH, in 2007. Estimated accuracy (for sandy bottoms) in water depths ranging 1–10 m are 0.07-0.10 m in the vertical, and on the order of 0.1-1 m horizontally depending on water depth and bottom slope. The high maneuverability of the personal watercraft makes very shallow water bathymetric surveys possible with acoustic altimeters, particularly in regions where airborne remote sensing systems fail (owing to water clarity issues) or where repeated high resolution surveys are required (e.g., where an erodible bottom is rapidly evolving)

From Periphery to Core: Economic Adjustments to High Speed Rail

This paper presents evidence that high speed rail systems, by bringing economic agents closer together, sustainably promote economic activity within regions that enjoy an increase in accessibility. Our results on the one hand confirm expectations that have led to huge public investments into high speed rail all over the world. On the other hand, they confirm theoretical predictions arising from a consolidate body of (New) Economic Geography literature taking a positive, man-made and reproducible shock as a case in point. We argue that the economic geography framework can help to derive ex-ante predictions on the economic impact of transport projects. The subject case is the German high speed rail track connecting Cologne and Frankfurt, which, as we argue, provides exogenous variation in access to regions due to the construction of intermediate stations in the towns of Limburg and Montabaur.NEG; high speed rail; transport policy; market access; acces-sibility

Support for and resistance against large stadia: the role of lifestyle and other socio-economic factors

From the Olympics to the World Cup, mega sporting events are a source of enjoyment for tens of thousands of people, but can also be a source of intense debate and controversy. This insightful new Handbook addresses a number of central questions, including: How are host cities selected and under what economic conditions? How are these events organized, and how is local resistance overcome? Based on historical and empirical experience, what are the pitfalls for the organizers of these events? What are the potential economic benefits, including any international image effects? How can the costs be minimized and the benefits maximized for host cities and countries? How do these mega events impact the challenges of globalization and what is their environmental legacy

Iteration-Complexity of a Generalized Forward Backward Splitting Algorithm

In this paper, we analyze the iteration-complexity of Generalized Forward--Backward (GFB) splitting algorithm, as proposed in \cite{gfb2011}, for minimizing a large class of composite objectives $f + \sum_{i=1}^n h_i$ on a Hilbert space, where $f$ has a Lipschitz-continuous gradient and the $h_i$'s are simple (\ie their proximity operators are easy to compute). We derive iteration-complexity bounds (pointwise and ergodic) for the inexact version of GFB to obtain an approximate solution based on an easily verifiable termination criterion. Along the way, we prove complexity bounds for relaxed and inexact fixed point iterations built from composition of nonexpansive averaged operators. These results apply more generally to GFB when used to find a zero of a sum of $n > 0$ maximal monotone operators and a co-coercive operator on a Hilbert space. The theoretical findings are exemplified with experiments on video processing.Comment: 5 pages, 2 figure