In this article, we introduce a simple distributed algorithm that assigns appropriate individual transmission powers to devices in a wireless ad hoc network. In contrast to many other proposed ...algorithms, it does without special hardware. It requires only local neighbourhood information and therefore avoids flooding information throughout the network. Finally, the cooperative nature of the algorithm avoids that devices cause excessive interference by using unnecessarily high transmission powers. By means of simulation, we show that the topologies created by this algorithm without any global knowledge are as effective as topologies resulting from a good choice of a common transmission power (which would require global knowledge) in terms of the achievable throughput. PUBLICATION ABSTRACT
The Dark Energy Spectroscopic Instrument (DESI) will provide precise measurements of Baryon Acoustic Oscillations (BAO) to constrain the expansion history of the Universe and set stringent ...constraints on dark energy. Therefore, precise control of the global error budget due to various systematic effects is required for the DESI 2024 BAO analysis. In this work, we focus on the robustness of the BAO analysis against the Halo Occupation Distribution (HOD) modeling for the Emission Line Galaxy (ELG) tracer. Based on a common dark matter simulation, our analysis relies on HOD mocks tuned to early DESI data, namely the One-Percent survey data. To build the mocks, we use several HOD models for the ELG tracer as well as extensions to the baseline HOD models. Among these extensions, we consider distinct recipes for galactic conformity and assembly bias. We perform two independent analyses in the Fourier space and in the configuration space. We recover the BAO signal from two-point measurements after performing reconstruction on our mocks. Additionally, we also apply the control variates technique to reduce sample variance noise. Our BAO analysis can recover the isotropic BAO parameter \(\alpha_\text{iso}\) within 0.1\% and the Alcock Paczynski parameter \(\alpha_\text{AP}\) within 0.3\%. Overall, we find that our systematic error due to the HOD dependence is below 0.17\%, with the Fourier space analysis being more robust against the HOD systematics. We conclude that our analysis pipeline is robust enough against the HOD systematics for the ELG tracer in the DESI 2024 BAO analysis.
CineMA: cooperation enhancement in MANETs Frank, M.; Martini, P.; Plaggemeier, M.
29th Annual IEEE International Conference on Local Computer Networks,
2004
Conference Proceeding
Mobile ad hoc networks are based on the assumption that all participants of the network cooperate and forward packets towards destinations. Unfortunately, there are no mechanisms to enforce ...cooperation. Thus, altruism and trust are two of the most important characteristics in mobile ad hoc networks. However what happens if there are selfish or even malicious nodes? Those nodes do not forward all packets to the next station. If the fraction of misleading nodes becomes too big, the throughput decreases significantly. This paper presents CineMA, a group based approach to improve the cooperation in mobile ad hoc networks.
Baryon Acoustic Oscillations can be measured with sub-percent precision above redshift two with the Lyman-alpha forest auto-correlation and its cross-correlation with quasar positions. This is one of ...the key goals of the Dark Energy Spectroscopic Instrument (DESI) which started its main survey in May 2021. We present in this paper a study of the contaminants to the lyman-alpha forest which are mainly caused by correlated signals introduced by the spectroscopic data processing pipeline as well as astrophysical contaminants due to foreground absorption in the intergalactic medium. Notably, an excess signal caused by the sky background subtraction noise is present in the lyman-alpha auto-correlation in the first line-of-sight separation bin. We use synthetic data to isolate this contribution, we also characterize the effect of spectro-photometric calibration noise, and propose a simple model to account for both effects in the analysis of the lyman-alpha forest. We then measure the auto-correlation of the quasar flux transmission fraction of low redshift quasars, where there is no lyman-alpha forest absorption but only its contaminants. We demonstrate that we can interpret the data with a two-component model: data processing noise and triply ionized Silicon and Carbon auto-correlations. This result can be used to improve the modeling of the lyman-alpha auto-correlation function measured with DESI.
Rev.esc.adm.neg
El objeto de esta investigación se centra en homologar un análisis cronológico de las etapas de la ...administración hasta llegar a su actual enfoque sistémico. Se inicia con los precursores de la administración desde la civilización China en la cual se sentaron las bases de un enfoque pragmático, y se abordan las diferentes etapas que condujeron a la humanidad hacia la revolución industrial cuando las maquinas sustituyeron a la mano de obra. El artículo presenta un análisis crítico del surgimiento de la administración científica como una respuesta a la creciente demanda por estilos más humanos y sociales para ordenar la labor administrativa. Aplicando un análisis metodológico de cada etapa de las teorías de la administración bajo la visión de un enfoque sistémico, detectando las características que fueron aportando a la construcción de los nuevos modelos y su desenlace en los modelos actuales con enfoque sistémico, revisando desde los principios de la administración científica establecidos por Taylor, hasta la crítica que señalaba la falta de atención de los diferentes factores psicológicos y sociales relacionados con el ser humano. Se concluye de esto que el nuevo enfoque sistémico es el resultado de un proceso de evolución de la teoría administrativa, así como del análisis de la adaptación y tropicalización de cada escuela administrativa con respecto a las necesidades de cada época, pero con una visión de futuro que conduce a una utopía con cierto grado de realismo.
When measuring the Baryon Acoustic Oscillations (BAO) scale from galaxy surveys, one typically assumes a fiducial cosmology when converting redshift measurements into comoving distances and also when ...defining input parameters for the reconstruction algorithm. A parameterised template for the model to be fitted is also created based on a (possibly different) fiducial cosmology. This model reliance can be considered a form of data compression, and the data is then analysed allowing that the true answer is different from the fiducial cosmology assumed. In this study, we evaluate the impact of the fiducial cosmology assumed in the BAO analysis of the Dark Energy Spectroscopic Instrument (DESI) survey Data Release 1 (DR1) on the final measurements in DESI 2024 III. We utilise a suite of mock galaxy catalogues with survey realism that mirrors the DESI DR1 tracers: the bright galaxy sample (BGS), the luminous red galaxies (LRG), the emission line galaxies (ELG) and the quasars (QSO), spanning a redshift range from 0.1 to 2.1. We compare the four secondary AbacusSummit cosmologies against DESI's fiducial cosmology (Planck 2018). The secondary cosmologies explored include a lower cold dark matter density, a thawing dark energy universe, a higher number of effective species, and a lower amplitude of matter clustering. The mocks are processed through the BAO pipeline by consistently iterating the grid, template, and reconstruction reference cosmologies. We determine a conservative systematic contribution to the error of \(0.1\%\) for both the isotropic and anisotropic dilation parameters \(\alpha_{\rm iso}\) and \(\alpha_{\rm AP}\). We then directly test the impact of the fiducial cosmology on DESI DR1 data.
Resumen Introducción La mHealth, definida como la prestación de información o asistencia sanitaria a través del uso de dispositivos móviles o tabletas, se postula como una de las grandes apuestas ...para pacientes, proveedores e inversores. Una app es un programa, con unas características especiales, que se instala en un dispositivo móvil, ya sea tableta digital o teléfono inteligente, y que suele tener un tamaño reducido, y cuyo objetivo es facilitar la consecución de una tarea determinada o asistir en gestiones diarias, siendo el modo de interacción entre el usuario y la aplicación el tacto. Objetivo El objetivo del presente trabajo fue realizar una revisión sistemática acerca de la información publicada sobre las apps enfocadas al campo de la neurorrehabilitación, con el fin de clasificarlas y llevar a cabo una descripción de las principales características de las mismas. Material y métodos Se realiza una revisión sistemática mediante búsqueda bibliográfica en bases de datos biomédicas, así como en otras fuentes de información propias del ámbito de las aplicaciones tipo apps. Se clasificaron las apps en 5 categorías: hábitos saludables, informativas, valoración, tratamiento y específicas. Conclusiones Existe gran cantidad de apps con potencial uso en el campo de la neurorrehabilitación, por lo que es importante que los desarrolladores y diseñadores apps conozcan cuáles son las necesidades de la población con patología neurológica para que sus productos sean válidos y eficaces en dicho contexto. Del mismo modo, los profesionales, pacientes, familiares y cuidadores deberían disponer de criterios claros e indicadores que pudieran ayudarles a seleccionar las aplicaciones óptimas para sus necesidades concretas.
Well exposed, diamond-line cut, quarry-exposures of the Manciano Sandstone allow a detailed analysis of sandy, fossiliferous, nearshore deposits of the shelf of the Northern Apennines. The Manciano ...Sandstone is characterized by medium to very coarse, washed, fairly well sorted, lithic sandstone, with thin interlayers of sandy conglomerates. It displays two principal, rhythmically alternating sandy facies: (a) slightly burrowed (mostly
Macaronichnus, Ophiomorpha, Skolithos) units, trough cross-bedded, locally showing possible tidal bundles with few whole
Scutella (echinoid) shells reworked on foresets, or occasional large-scale (approximately 2 m) planar cross-bedded, bar-accretion units; and (b) slightly finer, darker-coloured reddish-brown sandstone units, heavily bioturbated (
Cruziana-Skolithos) ichnofauna) representing slightly more sheltered settings. Large oysters are present in near-living position in a few thin layers and, more commonly, as reworked, comminuted fragments in sandy layers. Many calcareous pebbles and oyster fragments are bored. Other fossils consist of echinoids (
Scutella), some balanids and reworked foraminifera and bryozoa. The Manciano sands were deposited primarily in a wave-dominated shoreface, containing migrating bars/ridges and affected by wave-induced, possibly tidal-enhanced currents. This tidal influence confirms the opening of the Miocene Apenninic Sea to oceans, both the developing Atlantic Ocean to the west and, through a long, narrow seaway, the Asian portion of the Tethys Sea to the east.
We present the angular diameter distance measurement obtained with the
Baryonic Acoustic Oscillation feature from galaxy clustering in the completed
Dark Energy Survey, consisting of six years (Y6) ...of observations. We use the Y6
BAO galaxy sample, optimized for BAO science in the redshift range 0.6<$z$<1.2,
with an effective redshift at $z_{\rm eff}$=0.85 and split into six tomographic
bins. The sample has nearly 16 million galaxies over 4,273 square degrees. Our
consensus measurement constrains the ratio of the angular distance to sound
horizon scale to $D_M(z_{\rm eff})/r_d$ = 19.51$\pm$0.41 (at 68.3% confidence
interval), resulting from comparing the BAO position in our data to that
predicted by Planck $\Lambda$CDM via the BAO shift parameter
$\alpha=(D_M/r_d)/(D_M/r_d)_{\rm Planck}$. To achieve this, the BAO shift is
measured with three different methods, Angular Correlation Function (ACF),
Angular Power Spectrum (APS), and Projected Correlation Function (PCF)
obtaining $\alpha=$ 0.952$\pm$0.023, 0.962$\pm$0.022, and 0.955$\pm$0.020,
respectively, which we combine to $\alpha=$ 0.957$\pm$0.020, including
systematic errors. When compared with the $\Lambda$CDM model that best fits
Planck data, this measurement is found to be 4.3% and 2.1$\sigma$ below the
angular BAO scale predicted. To date, it represents the most precise angular
BAO measurement at $z$>0.75 from any survey and the most precise measurement at
any redshift from photometric surveys. The analysis was performed blinded to
the BAO position and it is shown to be robust against analysis choices, data
removal, redshift calibrations and observational systematics.
We present the first measurements of Lyman-$\alpha$ (Ly$\alpha$) forest
correlations using early data from the Dark Energy Spectroscopic Instrument
(DESI). We measure the auto-correlation of ...Ly$\alpha$ absorption using 88,509
quasars at $z>2$, and its cross-correlation with quasars using a further
147,899 tracer quasars at $z\gtrsim1.77$. Then, we fit these correlations using
a 13-parameter model based on linear perturbation theory and find that it
provides a good description of the data across a broad range of scales. We
detect the BAO peak with a signal-to-noise ratio of $3.8\sigma$, and show that
our measurements of the auto- and cross-correlations are fully-consistent with
previous measurements by the Extended Baryon Oscillation Spectroscopic Survey
(eBOSS). Even though we only use here a small fraction of the final DESI
dataset, our uncertainties are only a factor of 1.7 larger than those from the
final eBOSS measurement. We validate the existing analysis methods of
Ly$\alpha$ correlations in preparation for making a robust measurement of the
BAO scale with the first year of DESI data.
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