Quality externalities among hotel establishments: what is the impact of tour operators?

This paper is about quality decisions in a vertical structure where competitive producers sell to powerful retailers. Specifically, we focus the analysis on the role played by a tour operator (TO) on quality investments when distributing the capacity of a given tourist destination. We emphasize the presence of quality externalities among hotel establishments, and see that sometimes a TO distribution can provide a solution to the tragedy of the commons in qualityprovision. Thus, we analyze what implications do vertical relations have for quality in this industry, and then derive some policy recommendations. This paper is about quality decisions in a vertical structure where competitive producers sell to powerful retailers. Specifically, we focus the analysis on the role played by a tour operator (TO) on quality investments when distributing the capacity of a given tourist destination. We emphasize the presence of quality externalities among hotel establishments, and see that sometimes a TO distribution can provide a solution to the tragedy of the commons in qualityprovision. Thus, we analyze what implications do vertical relations have for quality in this industry, and then derive some policy recommendations

Copyright Protection of Color Imaging Using Robust-Encoded Watermarking

In this paper we present a robust-encoded watermarking method applied to color images for copyright protection, which presents robustness against several geometric and signal processing distortions. Trade-off between payload, robustness and imperceptibility is a very important aspect which has to be considered when a watermark algorithm is designed. In our proposed scheme, previously to be embedded into the image, the watermark signal is encoded using a convolutional encoder, which can perform forward error correction achieving better robustness performance. Then, the embedding process is carried out through the discrete cosine transform domain (DCT) of an image using the image normalization technique to accomplish robustness against geometric and signal processing distortions. The embedded watermark coded bits are extracted and decoded using the Viterbi algorithm. In order to determine the presence or absence of the watermark into the image we compute the bit error rate (BER) between the recovered and the original watermark data sequence. The quality of the watermarked image is measured using the well-known indices: Peak Signal to Noise Ratio (PSNR), Visual Information Fidelity (VIF) and Structural Similarity Index (SSIM). The color difference between the watermarked and original images is obtained by using the Normalized Color Difference (NCD) measure. The experimental results show that the proposed method provides good performance in terms of imperceptibility and robustness. The comparison among the proposed and previously reported methods based on different techniques is also provided

Quenched Spectroscopy for the N=1 Super-Yang-Mills Theory

We present results for the Quenched SU(2) N=1 Super-Yang-Mills spectrum at $\beta=2.6$, on a $V=16^3 \times 32$ lattice, in the OZI approximation. This is a first step towards the understanding of the chiral limit of lattice N=1 SUSY.Comment: 3 pages, Latex, 2 ps figures, contribution to Lattice 97, Edinburgh 22-26 July 1997; to appear on Nucl. Phys. B. (Proc. Suppl.

True high-order VCO-based ADC

A novel approach to use a voltage-controlled oscillator (VCO) as the first integrator of a high-order continuous-time delta-sigma modulator (CT-DSM) is presented. In the proposed architecture, the VCO is combined with a digital up-down counter to implement the first integrator of the CT-DSM. Thus, the first integrator is digital-friendly and hence can maximally benefit from technological scaling

Optimization of the investment casting process

Rapid prototyping is an important technique for manufacturing. This work refers to the manufacture of hollow patterns made of polymeric materials by rapid prototyping technologies for its use in the preparation of ceramic molds in the investment casting process. This work is focused on the development of a process for manufacturing patterns different from those that currently exist due to its hollow interior design, allowing its direct use in the fabrication of ceramic molds; avoiding cracking and fracture during the investment casting process, which is an important process for the foundry industry