This paper presents the experimental set-up description and some results of a channel impulse response measurement campaign. The measurements were performed in the frequency domain, in the 40 GHz band, and the channel impulse response was obtained applying spectral analysis. A wide indoor sports pavilion was selected for the experiments, considering several static discrete positions for the mob...

This paper demonstrates a novel approach to determining the optimum guard interval for a multicarrier code division multiple access (MC-CDMA) system. Analytical expressions for useful and interference power are derived as a basis for comparison. From these, an expression for the signal-to-noise ratio of a detected bit is derived and used to determine the optimum guard interval for a given chann...

Entity-Relationship modelling is a popular technique for data modelling. Despite its popularity and wide spread use, it lacks a firm semantic foundation. We propose a translation of an ER-model into relation algebra, suggesting that this kind of algebra does provide suitable mechanisms for establishing a formal semantics of Entity-Relationship modelling. The work reported on here deals first wi...

Motivated by the observed rise in the trade of technology, I analyze how technology would spread in a frictionless market. In such a world, low-skilled agents prefer to use old technology because it costs less; their skills do not justify the use of frontier technology. The model generates a technology-life cycle of somewhere between 68 and 124 years and per-capita income differential factors b...

We investigate how borrowers’ corporate governance influences bank loan contracting terms in emerging markets and how this relation varies across countries with different country-level governance. We find that borrowers with stronger corporate governance obtain favorable contracting terms with respect to loan amount, maturity, collateral requirements, and spread. Firm-level and country-level co...

It is well known that members of families of polynomials, that are orthogonal with respect to an inner product determined by a nonnegative measure on the real axis, satisfy a three-term recursion relation. Analogous recursion formulas are available for orthogonal Laurent polynomials with a pole at the origin. This paper investigates recursion relations for orthogonal rational functions with arb...

A small macroeconomic model is constructed starting from a German money demand relation for M3 based on quarterly, seasonally unadjusted data for the period from 1976 to 1996. In contrast to previous studies we build a vector error correction model for M3, GNP, an innation rate and an interest rate spread variable to represent opportunity costs of holding money. Furthermore, import price innati...

In this paper a brief survey of multiple orthogonal polynomials defined using orthogonality conditions spread out over r different measures are given. We consider multiple orthogonal polynomials on the real line, as well as on the unit semicircle in the complex plane. Such polynomials satisfy a linear recurrence relation of order r+1, which is a generalization of the well known three-term recur...

Velocity dispersion σ, radius R and luminosity L of elliptical galaxies are known to be related, leaving only two degrees of freedom and defining the so-called “fundamental plane”. In this Letter we present observational evidence that rich galaxy clusters exhibit a similar behaviour. Assuming a relation L ∝ Rασ2β, the best-fit values of α and β are very close to those defined by galaxies. The d...