Search results for "Average duration"
showing 10 items of 10 documents
Level-crossing rate and average duration of fades of non-stationary multipath fading channels
2017
The level-crossing rate (LCR) and average duration of fades (ADF) are important statistical quantities describing the fading behaviour of mobile radio channels. To date, these quantities have only been analysed under the assumption that the mobile radio channel is wide-sense stationary, which is generally not the case in practice. In this paper, we propose a concept for the analysis of the LCR and ADF of non-stationary channels. Rice's standard formula for the derivation of the LCR of wide-sense stationary processes is extended to a more general formula enabling the computation of the instantaneous LCR of non-stationary processes. The application of the new concept results in closed-form ex…
Tourism Statistics for Destination Management: The Trips/Arrivals Model
2014
Simply counting the number of tourists in a destination is not as simple as one might initially think. The present work intends to formalize a conceptual model by decomposing tourism nights, trips, and average duration of visit in a given destination, in terms of quantities and parameters that only for a small part could be derived from official tourism statistics. On the other hand, most of the quantities and parameters required for determining the number of tourists in a given destination are in general unknown, and need to be (directly or indirectly) estimated. Empirical evidences resulting from a survey on incoming tourism in Sicily are provided, showing the biases affecting supply-side…
Variations in teaching of removable partial dentures in Spanish dental schools
2010
Objectives: Despite the increasing demand for implant-based treatments, removable partial dentures (RPDs) are frequently used in the oral rehabilitation of partially dentate patients. Furthermore, the Bologna Declaration Agreement (1999) promotes the freedom of movement both of students among dental schools and of graduates across the European Union (EU). Given that inconsistency in teaching among dental schools may lead to confusion, this study aimed to evaluate the status of teaching and clinical experience reached by undergrad uate dentalstudents in Spanish dental schools in relation to RPDs. Study design: A questionnaire seeking information on the preclinical and clinical teaching of RP…
Spillovers from the oil sector to the housing market cycle
2017
We assess the spillovers from the oil sector to the housing market cycle using quarterly data for 20 net oil-exporting and -importing industrial countries, and employing continuous- and discrete-time duration models. We do not uncover a statistically significant difference in the average duration of booms and normal times in the housing markets of those net oil-importers and net oil-exporters. Similarly, the degree of exposure to commodity price fluctuations does not seem to significantly affect the housing market cycle. However, we find that housing booms are shorter when oil prices increase than housing busts when oil prices decrease. We also show that the net oil-importers are more vulne…
Biostratigraphy of Triassic Ammonoids
2015
The Triassic is a turning point in the evolutionary history of ammonoids, characterized by the flourishing Ceratitida and the appearance of the first heteromorphs. Following the end-Permian mass extinction, ammonoids were among the first groups to rediversify by producing many new taxa. Already in the late nineteenth century, the still currently recognized Triassic stages and substages were introduced. The historical development of Triassic ammonoid biostratigraphy is a good example of worldwide cooperation between many geographically-diverse research groups, which initially began in Germany and the European Alps. This cooperation was then extended to North America, Transcaucasia, North Ind…
Statistical Properties of Double Hoyt Fading With Applications to the Performance Analysis of Wireless Communication Systems
2018
In this paper, we investigate the statistical properties of double Hoyt fading channels, where the overall received signal is determined by the product of two statistically independent but not necessarily identically distributed single Hoyt processes. Finite-range integral expressions are first derived for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades of the envelope fading process. A closed-form approximate solution is also deduced for the LCR by making use of the Laplace approximation theorem. Applying the derived PDF of the double Hoyt channel, we then provide analytical expressions for the average…
Transrenal ureteral occlusion: results and problems.
1994
Purpose The effectiveness of transrenal ureteral occlusion was evaluated. Patients and Methods Transrenal ureteral occlusions were performed in 83 ureters of 76 patients. Thirty-one ureters were occluded with use of tissue adhesive, which was secured in place with Gianturco coils in 21. Fifty-two ureters were occluded by means of silicone-filled, detachable latex balloons. Average follow-up was 3.6 months (range, 1 week to 38 months) for patients treated with the tissue adhesive and 7.9 months (range, 1 week to 61 months) for patients treated with the detachable balloons. Results Seventeen (55%) of the 31 ureters occluded with tissue adhesive and 36 (69%) of the 52 ureters occluded with det…
Internet-Based Employer Search and Vacancy Duration: Evidence from Finland
2014
This study investigates the effect of the introduction of the public employment agency's Internet-based service on the duration of employer search. The analysis exploits the introduction of a web-based service by the Finnish Employment Agency in October 2002. The results, based on information on job vacancies announced via the public employment agency between 2002 and 2003, indicate that the introduction of the web service, in general, shortened the duration of employer search. However, we find that the introduction of the web-based service shortened the average duration of vacancies in some regions but not in others. In addition, employers in urban areas were more likely to benefit from th…
The Impact of Shadowing and the Severity of Fading on the First and Second Order Statistics of the Capacity of OSTBC MIMO Nakagami-Lognormal Channels
2011
Published version of an article in Wireless Personal Communications (2011), 1-16. Also available from the publisher at http://dx.doi.org/10.1007/s11277-011-0275-x This article presents a thorough statistical analysis of the capacity of orthogonal space-time block coded (OSTBC) multiple-input multiple-output (MIMO) Nakagami- lognormal (NLN) channels. The NLN channel model allows to study the joint effects of fast fading and shadowing on the statistical properties of the channel capacity. We have derived exact analytical expressions for the probability density function (PDF), cumulative distribution function (CDF), level-crossing rate (LCR), and average duration of fades (ADF) of the capacity…
An Exact Solution for the Level-Crossing Rate and the Average Duration of Fades of the Envelope of Sum-of-Cisoids Processes
2012
Authors version of an article published in the journal: Procedia Technology. Also available from the publisher at: http://dx.doi.org/10.1016/j.protcy.2012.03.004 Sum-of-cisoids (SOC) processes provide a physically and numerically appealing framework for the modelling and simulation of a wide class of mobile radio channels. This paper is concerned with the problem of finding a general solution for the level-crossing rate (LCR) and the average duration of fades (ADF) of the envelope of SOC processes. Exact expressions are derived for the LCR and the ADF by taking into account that the inphase component, the quadrature component, and the time derivatives of the inphase and quadrature component…