it is necessary to perform a proper planning for an efficient deployment of new infrastructure for transmission of digital television in countries that have adopted such technology. In that sense, the coverage prediction process, which makes use of path loss propagation models, plays an important role. The log-distance path loss model determines that the average power loss depends logarithmically on the distance and it has a parameter called propagation exponent which is required to be calculated for each studied environment. This paper describes the adjustments made to the log-distance path loss model using data from three sets of signal strength measurements in Lima, Peru. Through a series of iterations, two computationally simple models for estimating the average path loss were obtained. The performance of the models were evaluated comparing their results with those calculated using Okumura-Hata and the Rec. ITU-R P.1546 model, showing good results. The proposed strategy used here can be applied to any other environment of propagation to estimate the path loss.
The red squat lobster Pleuroncodes monodon is an important fishery resource in the Humboldt Current System (HCS). This decapod is exploited in two fishing units: (a) the northern fishing unit (NFU, from 26°S to 30°S) and (b) the southern fishing unit (SFU, from 32°S to 37°S), each of which have an adjacent nursery area that is the source of recruits to replace the exploited adult populations (in the NFU: off the coast of Coquimbo (28°S) and in the SFU: off the coast of Concepción (36°S)). Marked spatial differences in the environmental conditions of the NFU and SFU, and the biogeographic break that exists between these nursery areas (30°S) may promote changes in the bioenergetic condition of new P. monodon juveniles. To evaluate this, we analyzed the bioenergetic condition (measured as: body mass, lipids, proteins, glucose, and energy) of new juvenile females in the main nursery areas off the Chilean coast. The juvenile females from the SFU showed a higher body mass than those from the NFU. Consistently, the juvenile females from the SFU had a higher content of lipids, proteins, and glucose than those from the NFU, indicative of higher energy contents and a higher lipid/protein ratio in the south compared to the north. Considering the current overexploitation of this fishery resource in the HCS, it is essential to understand how the bioenergetic condition of juvenile females of P. monodon may vary in nursery areas at different latitudes in order to generate sustainable fishery management policies with an ecological approach, designed specifically to each fishing unit. Furthermore, identifying the latitudinal variations of these biochemical compounds in P. monodon juveniles can elucidate the geographic origin of red squat lobsters that present a ”better bioenergetic condition” in the HCS, which may significantly benefit sustainable fishing certification processes.
Evaluation of coverage and service of television systems requires the application of normalized procedures in order to compare data obtained in different measurement campaigns. There is a large quantity of documentation about general aspects of these processes, which is useful in the stage of planning. This is not the case when detailed aspects like the correct configuration of the measuring equipment or processing of collected data are required. This document pretends to provide some practical information about testing of coverage and service of analog and digital television transmitter systems.
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