BACKGROUND AND PURPOSE Dual-energy X-ray absorptiometry (DXA) is a precise method to study changes in bone mineral density (BMD), including the pattern of bone remodeling around an implant. Results from implant studies are usually presented as changes in BMD as a function of time. The baseline and reference value for such calculations is the first measurement after the operation. The baseline m...

We study estimation in quantile regression when covariates are measured with errors. Existing methods require stringent assumptions, such as spherically symmetric joint distribution of the regression and measurement error variables, or linearity of all quantile functions, which restrict model flexibility and complicate computation. In this paper, we develop a new estimation approach based on co...

Hearing loss is one of the most common conditions related to aging, and previous descriptive evidence links it to early exit from the labor market. These studies are usually based on self-reported hearing difficulties, which are potentially endogenous to labor supply. We use unique representative data collected in the spring of 2005 through in-home interviews. The data contains self-reported fu...

E ective risk management requires adequate risk measurement. A basic problem herein is the quanti cation of market risks: what is the overall e ect on a portfolio if market rates change? The rst chapter gives a brief review of the standard risk measure \Value{At{Risk" (VAR) and introduces the concept of \Maximum Loss" (ML) as a method for identifying the worst case in a given scenario space, ca...

Quantum private queries (QPQ) is an important cryptography protocol aiming to protect both the user's and database's privacy when the database is queried privately. Recently, a variety of practical QPQ protocols based on quantum key distribution (QKD) have been proposed. However, for QKD-based QPQ the user's imperfect detectors can be subjected to some detector- side-channel attacks launched by...

We consider the problem of silent email loss in the Internet, where neither the sender nor the intended recipient is notified of the loss. Our detailed measurement study over several months shows a silent email loss rate of 0.71% to 1.02%. The silent loss of an important email can impose a high cost on users. We further show that spam filtering can be the significant cause of silent email loss,...

A framework for a physical interpretation of quantum cosmology appropriate to a nonperturbative hamiltonian formulation is proposed. It is based on the use of matter fields to define a physical reference frame. In the case of the loop representation it is convenient to use a spatial reference frame that picks out the faces of a fixed simplicial complex and a clock built with a free scalar field...

Understanding and modelling packet loss in the Internet is especially relevant for the design and analysis of delay-sensitive multimedia applications. In this paper, we present analysis of hours of endto-end unicast and multicast packet loss measurement. From these we selected hours of stationary traces for further analysis. We consider the dependence as seen in the autocorrelation function of ...