Distributed primary user identification from imprecise location information

We study a cognitive radio scenario in which the network of sec- ondary users wishes to identify which primary user, if any, is trans- mitting. To achieve this, the nodes will rely on some form of location information. In our previous work we proposed two fully distributed algorithms for this task, with and without a pre-detection step, using propagation parameters as the only source of location information. In a real distributed deployment, each node must estimate its own po- sition and/or propagation parameters. Hence, in this work we study the effect of uncertainty, or error in these estimates on the proposed distributed identification algorithms. We show that the pre-detection step significantly increases robustness against uncertainty in nodes' locations.

GIS analysis for the study of rural depopulation: the Kingdom of Valencia (Tomas Lopez 1789)

One of the more aspects that have shaped the landscape is the human impact. The human impact has the clearest indicator of the density of settlements in a particular geographic region. In this paper we study all settlements shown on the map of the Kingdom of Valencia, Spain Geographic Atlas (AGE) of Tomas Lopez (1788), and their correspondence with the current ones. To meet this goal we have developed a specific methodology, the systematic study of all existing settlements in historical cartography. This will determine which have disappeared and which have been renamed. The material used has been the historical cartography of Tomas Lopez, part of the AGE (1789), the Kingdom of Valencia (1789), sheets numbers (78, 79, 80 and 81); Current mapping of the provinces of Alicante, Valencia, Castellon, Teruel, Tattagona and Cuenca; As main software ArcGis V.9.3. The steps followed in the methodology are as follows: 1. Check the scale of the maps. Analyze the possible use of a spherical earth model. 2. Geo-reference of maps with latitude and longitude framework. Move the historical longitude origin to the origin longitude of modern cartography. 3 Digitize of all population settlements or cities. 4 Identify historic settlements or cities corresponding with current ones. 5. If the maps have the same orientation and scale, replace the coordinate transformation of historical settlements with a new one, by a translation in latitude and longitude equal to the calculated mean value of all ancient map points corresponding to the new. 6. Calculation of absolute accuracy of the two maps, i.e. the linear distance between the points of both maps. 7 draw in the GIS, the settlements without correspondence, in the current coordinates, and with a circle of mean error of the sheet, in order to locate their current location. If there are actual settlements exist within this circle, they are candidates to be the searched settlements. We analyzed more than 2000 settlements represented in the Atlas of Tomas Lopez of the Kingdom of Valencia (1789), of which almost 14.5% have no correspondence with the existing settlements. The rural landscape evolution of the Valencia, oldest kingdom of Valencia, one can say that can be severely affected by the anthropization suffered in the period from 1789 to the present, since 70% of existing settlements actually have appeared after Tomas Lopez¿s cartography, dated on 1789

Assessment of watercore development in apples with MRI: Effect offruit location in the canopy

tWatercore distribution inside apple fruit (block or radial), and its incidence (% of tissue) were relatedto the effect of solar radiation inside the canopy as measured by a set of low-cost irradiation sensors.221 samples were harvested in two seasons from the top and the bottom of the canopy and submittedto the non-invasive and non-destructive technique of magnetic resonance imaging (MRI) in order toobtain 20 inner tomography slices from each fruit and analyze the damaged areas using an interactive3D segmentation method. The number of fruit corresponding to each type of damage and the relevantpercentage were calculated and it was found that apples from the top of the tree were mainly of the radialtype (84%) and had more watercore (approx. 5% more) than apples from the bottom (65% radial). From theimage segmentation, the Euler number, a morphometric parameter, was extracted from the segmentedimages and related to the type of watercore symptoms. Apples with block watercore were grouped inEuler numbers between −400 and 400 with a small evolution. For apples with radial development, theEuler number was highly negative: up to −1439. Significant differences were also found regarding sugarcomposition, with higher fructose and total sugar contents in apples from the upper canopy, compared tothose in the lower canopy location. In the seasons studied (2011 and 2012), significantly higher sorbitoland lower sucrose and fructose contents were found in watercore-affected tissue compared to the healthytissue of affected apples and also compared to healthy apples.

Evaluation of the Grounding Circuit Measurements for Stator Ground-Fault Location of Synchronous Generators

Locating stator-winding ground faults accurately is a very difficult task. In this paper the grounding circuit measurements are evaluated in order to obtain information about the stator ground-fault location in synchronous generators. In power generators grounded through a high impedance, the relation between the neutral voltage and the phase voltage provide a first estimation of the fault location. The location error by using this ratio depends on the fault resistance and the value of the capacitance to ground of the stator winding. However, the error added by ignoring the value of the fault resistance is the most relevant term. This location estimation and the location error have been evaluated through the data of a real synchronous machine.

Regression analysis of top of descent location for idle-thrust descents

In this paper, multiple regression analysis is used to model the top of descent (TOD) location of user-preferred descent trajectories computed by the flight management system (FMS) on over 1000 commercial flights into Melbourne, Australia. In addition to recording TOD, the cruise altitude, final altitude, cruise Mach, descent speed, wind, and engine type were also identified for use as the independent variables in the regression analysis. Both first-order and second-order models are considered, where cross-validation, hypothesis testing, and additional analysis are used to compare models. This identifies the models that should give the smallest errors if used to predict TOD location for new data in the future. A model that is linear in TOD altitude, final altitude, descent speed, and wind gives an estimated standard deviation of 3.9 nmi for TOD location given the trajectory parame- ters, which means about 80% of predictions would have error less than 5 nmi in absolute value. This accuracy is better than demonstrated by other ground automation predictions using kinetic models. Furthermore, this approach would enable online learning of the model. Additional data or further knowledge of algorithms is necessary to conclude definitively that no second-order terms are appropriate. Possible applications of the linear model are described, including enabling arriving aircraft to fly optimized descents computed by the FMS even in congested airspace.