Deformation and Failure of Amorphous Solidlike Materials

Since the 1970's, theories of deformation and failure of amorphous, solidlike materials have started with models in which stress-driven, molecular rearrangements occur at localized flow defects via "shear transformations". This picture is the basis for the modern theory of "shear transformation zones" (STZ's), which is the focus of this review. We begin by describing the structure of the theory in general terms and by showing several applications, specifically: interpretation of stress-strain measurements for a bulk metallic glass, analysis of numerical simulations of shear banding, and the use of the STZ equations of motion in free-boundary calculations. In the second half of this article, we focus for simplicity on what we call an "athermal" model of amorphous plasticity, and use that model to illustrate how the STZ theory emerges within a systematic formulation of nonequilibrium thermodynamics.Comment: 28 pages, 4 figures, submitted to Annual Reviews of Condensed Matter Physic

Simulations for Multi-Object Spectrograph Planet Surveys

Radial velocity surveys for extra-solar planets generally require substantial amounts of large telescope time in order to monitor a sufficient number of stars. Two of the aspects which can limit such surveys are the single-object capabilities of the spectrograph, and an inefficient observing strategy for a given observing window. In addition, the detection rate of extra-solar planets using the radial velocity method has thus far been relatively linear with time. With the development of various multi-object Doppler survey instruments, there is growing potential to dramatically increase the detection rate using the Doppler method. Several of these instruments have already begun usage in large scale surveys for extra-solar planets, such as FLAMES on the VLT and Keck ET on the Sloan 2.5m wide-field telescope. In order to plan an effective observing strategy for such a program, one must examine the expected results based on a given observing window and target selection. We present simulations of the expected results from a generic multi-object survey based on calculated noise models and sensitivity for the instrument and the known distribution of exoplanetary system parameters. We have developed code for automatically sifting and fitting the planet candidates produced by the survey to allow for fast follow-up observations to be conducted. The techniques presented here may be applied to a wide range of multi-object planet surveys.Comment: 15 pages, 10 figures, accepted for publication in MNRA

Backward-bending new housing supply curve: evidence from China

This paper tests the existence of a backward-bending housing supply relationship in China, and estimates price elasticity of new housing supply for 35 major Chinese cities. Based on the panel data model of 35 cities, it is found that the response of housing supply to price change is relatively insensitive in China, and the supply elasticity has decreased with the rise in housing price. As a result, the remarkable increase in housing prices in China can be at least partly attributed to the inelastic housing supply. The results from this paper may inform Chinese government to take effective measures to reduce the large amount of idle land so as to increase the supply for the housing market

The impact of government land supply on housing starts

This paper investigates the impact of government land supply on new residential construction. By estimating a housing supply equation using a panel data set covering 35 major Chinese cities for the period of 1999 to 2010, it is found that the quantity of the land sold by the government is tightly associated with the number of housing starts. Two -or three - year lag of land sales has a larger impact on new construction than one- year lag , which is consistent with the fact that there is normally a two- to three-year interval between the date of land transaction and the date when construction is initiated. It is also found that the decrease in land sales accounts for a large proportion of the decrease in new construction in Beijing, Shanghai and Shenzhen. The estimates of city -specific supply elasticities are provided based on the housing supply model, it is found that housing price appreciation tends to be more considerable in cities with inelastic supply

Direct Government Control Over Residential Land Supply And Its Impact On Real Estate Market: Evidence From Major Chinese Market

In the early and mid - 2000s, the development of land reserve system promoted a structural change in residential land market in urban China, and the municipal government has become the sole supplier of urban residential land after the structural change. This paper examines the impact that direct government control over residential land supply has on real estate markets in major Chinese cities. It is found that there is a significant decrease in land supply after the establishment of direct government control over residential land supply, and the decrease in land supply has put downward pressure on new housing supply. It is also found that there is a decline in the price elasticity of new housing supply in the period characterized by more restrictive land supply

Learning Temporal Transformations From Time-Lapse Videos

Based on life-long observations of physical, chemical, and biologic phenomena in the natural world, humans can often easily picture in their minds what an object will look like in the future. But, what about computers? In this paper, we learn computational models of object transformations from time-lapse videos. In particular, we explore the use of generative models to create depictions of objects at future times. These models explore several different prediction tasks: generating a future state given a single depiction of an object, generating a future state given two depictions of an object at different times, and generating future states recursively in a recurrent framework. We provide both qualitative and quantitative evaluations of the generated results, and also conduct a human evaluation to compare variations of our models.Comment: ECCV201