Strong Structural Controllability of Systems on Colored Graphs

This paper deals with structural controllability of leader-follower networks. The system matrix defining the network dynamics is a pattern matrix in which a priori given entries are equal to zero, while the remaining entries take nonzero values. The network is called strongly structurally controllable if for all choices of real values for the nonzero entries in the pattern matrix, the system is controllable in the classical sense. In this paper we introduce a more general notion of strong structural controllability which deals with the situation that given nonzero entries in the system's pattern matrix are constrained to take identical nonzero values. The constraint of identical nonzero entries can be caused by symmetry considerations or physical constraints on the network. The aim of this paper is to establish graph theoretic conditions for this more general property of strong structural controllability.Comment: 13 page

Capitalization of Central Government Grants into Local House Prices

We explore the impact of central government grants on local house prices in England using a panel data set of local authorities (LAs) from 2001 to 2008. Electoral targeting of grants to LAs by the incumbent national government provides an exogenous source of variation in grants that we exploit to identify their causal effect on house prices. Our results indicate substantial or even full capitalization. We also find that house prices respond more strongly in locations in which new construction is constrained by physical barriers. Our results imply that (i) during our sample period grants were largely used in a way that is valued by the marginal homebuyer and (ii) increases in grants to a LA may mainly benefit the typically better off property owners (homeowners and absentee landlords) in that LA.

The impact of supply constraints on house prices in England

We explore the impact of different types of supply constraints on House prices in England by exploiting a unique panel dataset of 353 local planning authorities ranging from 1974 to 2008. Using exogenous variation from a policy reform, vote shares and historical density to identify the endogenous constraints-measures, we find that: i) Regulatory constraints have a substantive positive impact on the house price-earnings elasticity; ii) The effect of constraints due to scarcity of developable land is largely confined to highly urbanised areas; iii) Uneven topography has a quantitatively less meaningful impact; and iv) The effects of supply constraints are greater during boom than bust periods

The impact of supply constraints on house prices in England

We test the theoretical prediction that house prices respond more strongly to changes in local earnings in places with tight supply constraints using a unique panel dataset of 353 Local Planning Authorities in England between 1974 and 2008. Exploiting exogenous variation from a policy reform, vote shares and historical density to identify the endogenous constraints‐measures, we find that: regulatory constraints have a substantive positive impact on the house price‐earnings elasticity; the effect of constraints due to scarcity of developable land is largely confined to highly urbanised areas; and uneven topography has a quantitatively less meaningful impact

Why are house prices in London so high?

Strict regulation is affecting supply in the South East's property market, argue Christian Hilber and Wouter Vermeule

Fluctuating Nonlinear Spring Model of Mechanical Deformation of Biological Particles

We present a new theory for modeling forced indentation spectral lineshapes of biological particles, which considers non-linear Hertzian deformation due to an indenter-particle physical contact and bending deformations of curved beams modeling the particle structure. The bending of beams beyond the critical point triggers the particle dynamic transition to the collapsed state, an extreme event leading to the catastrophic force drop as observed in the force (F)-deformation (X) spectra. The theory interprets fine features of the spectra: the slope of the FX curves and the position of force-peak signal, in terms of mechanical characteristics --- the Young's moduli for Hertzian and bending deformations E_H and E_b, and the probability distribution of the maximum strength with the strength of the strongest beam F_b^* and the beams' failure rate m. The theory is applied to successfully characterize the $FX$ curves for spherical virus particles --- CCMV, TrV, and AdV

Magneto-optic contact for application in an amplifying waveguide optical isolator

We present the development of a metal-semiconductor contact for a TM-mode amplijying waveguide optical isolator and show that it is a compromise between good (magneto-)optical performance and good electrical behavior