We empirically estimate the substitutability of fixed and mobile services for telecommunications access using a large, U.S. household survey conducted over the period 1999-2001. We find significant positive cross-price elasticities between mobile and wireline usage. Because mobile usage prices fell dramatically over this period, we estimate that wireline usage may have been about 50% higher had...

We empirically estimate the substitutability of fixed and mobile services for telecommunications access using a large, U.S. household survey conducted over the period 1999-2001. We find significant positive cross-price elasticities between mobile and wireline usage. Because mobile usage prices fell dramatically over this period, we estimate that wireline usage may have been about 50% higher had...

BACKGROUND The benefits of antiretroviral therapy during early human immunodeficiency virus type 1 (HIV-1) infection remain unproved. METHODS A5217 study team randomized patients within 6 months of HIV-1 seroconversion to receive either 36 weeks of antiretrovirals (immediate treatment [IT]) or no treatment (deferred treatment [DT]). Patients were to start or restart antiretroviral therapy if ...

The Nonlocal Data and Smoothness (NDS) filtering framework for greyvalue images has been recently proposed by Mrázek et al. This model for image denoising unifies M-smoothing and bilateral filtering, and several well-known nonlinear filters from the literature become particular cases. In this article we extend this model to so-called matrix fields. These data appear, for example, in diffusion t...

To enable copyright protection and authentication, robust digital watermark can be embedded into multimedia contents imperceptibly. However, geometric distortions pose a significant threat to robust image watermarking because it can desynchronize the watermark information while preserving the visual quality. To overcome this, we developed an invariant domain with three transforms; Fast Fourier ...

Carbonate reservoirs rock typing plays a pivotal role in the construction of reservoir static models and volumetric calculations. The procedure for rock type determination starts with the determination of depositional and diagenetic rock types through petrographic studies of the thin sections prepared from core plugs and cuttings. In the second step of rock typing study, electrofacies are deter...

We have examined the thermodynamics of binding of a series of oligolysines (net charge z = +2 to +10) containing one, two, or three tryptophans to several single-stranded (ss) homo-polynucleotides [poly(A), poly(C), poly(I), poly(dU), poly(dT)] and duplex (ds) DNA in order to investigate the effects of peptide charge, tryptophan content, and polynucleotide base and sugar type. Equilibrium assoc...

Desmoid tumours (DTs) are soft tissue monoclonal neoplasms exhibiting a unique phenotype, consisting of aggressive local invasiveness without metastatic capacity. While DTs can infrequently occur as part of familial adenomatosis polyposis, most cases arise sporadically. Sporadic DTs harbour a high prevalence of CTNNB1 mutations and hence increased β-catenin signalling. However, β-catenin downst...

It is shown that for any signal x ( t ) the minimum of1;-1:-[ ( t tx? + (f f)z]SP) ( t , f ) dt df Manuscript received July 18, 1988; revised May 16, 1989.The author is with Philips Research Laboratories, 5600 JA Eindhoven,IEEE Log Number 9040410.The Netherlands. 1053-587X/91/0100-0202$01.00