There are considerable difficulties in the way of the development of useful and reliable simulation models of social phenomena, including that any simulation necessarily includes many assumptions that are not directly supported by evidence. Despite these difficulties, many still hope to develop quite general models of social phenomena. This paper argues that such hopes are ill-founded, in other...

We investigate the relationship between controversial roll call votes and support for Democratic incumbents in the 2010 midterm elections. Consistent with previous analyses, we find that supporters of health care reform paid a significant price at the polls. We go beyond these analyses by identifying a mechanism for this apparent effect: constituents perceived incumbents who supported health ca...

Providing fair share of bandwidth is critical to support communicationintensive applications in a shared-medium, capacity-constrained, largescale infrastructureless wireless network. The proposed design has to be distributed, scalable and address the issue of location-dependent contention. In this paper, we present a novel packet scheduling solution that achieves distributed fair service in suc...

Today’s WLANs offer high data rates of up to 11 and 54 Mbps for IEEE 802.11b respective 802.11a/g making this technology very attractive for real-time applications like VoIP calls. However, only a certain part of communication can take place at high data rates. Additionally, a certain amount of overhead is introduced by the CSMA/CA-based medium access scheme. Thus, challenging questions remain ...

If surfaces from a scene are visually indistinguishable under one light, they may become distinguishable under another. The aim here was to test whether the frequency of such metamerism can be predicted by a statistical property of the colours of a scene, namely their conditional entropy. Simulations were based on 50 hyperspectral images of natural scenes under sunlight and north skylight. The ...

In this paper we propose new nonparametric estimators for a family of conditional mutual information and divergences. Our estimators are easy to compute; they only use simple k nearest neighbor based statistics. We prove that the proposed conditional information and divergence estimators are consistent under certain conditions, and demonstrate their consistency and applicability by numerical ex...

A new simulation approach, called ‘subset simulation’, is applied to computing small first excursion probabilities for dynamical systems with stochastic excitations. The basic idea is to express the first excursion probability as a product of larger conditional failure probabilities by introducing intermediate failure boundaries. With a proper choice of the intermediate boundaries, the original...

Engle and Manganelli (2004) propose CAViaR, a class of models suitable for estimating conditional quantiles in dynamic settings. Engle and Manganelli apply their approach to the estimation of Value at Risk, but this is only one of many possible applications. Here we extend CAViaR models to permit joint modeling of multiple quantiles, Multi-Quantile (MQ) CAViaR. We apply our new methods to estim...

This paper investigates testing conditional independence between Y and Z given λθ(X) for some θ ∈ Θ ⊂ R, for a function λθ(·) known upto a parameter θ ∈ Θ. First, the paper proposes a new method of conditional martingale transforms under which tests are asymptotically pivotal and asymptotically unbiased against √ n-converging Pitman local alternatives. Second, the paper performs an analysis of ...