Search results for " codes"
showing 10 items of 147 documents
Roughness and vegetation parameterizations at L-band for soil moisture retrievals over a vineyard field
2015
Abstract The capability of L-band radiometry to monitor surface soil moisture (SM) at global scale has been analyzed in numerous studies, mostly in the framework of the ESA SMOS and NASA SMAP missions. To retrieve SM from L-band radiometric observations, two significant effects have to be accounted for, namely soil roughness and vegetation optical depth. In this study, soil roughness effects on retrieved SM values were evaluated using brightness temperatures acquired by the L-band ELBARA-II radiometer, over a vineyard field at the Valencia Anchor Station (VAS) site during the year 2013. Different combinations of the values of the model parameters used to account for soil roughness effects (…
Comparison of measured brightness temperatures from SMOS with modelled ones from ORCHIDEE and H-TESSEL over the Iberian Peninsula
2017
19 pges, 10 figures, 6 tables
The scattering and re-absorption of red and near-infrared chlorophyll fluorescence in the models Fluspect and SCOPE
2019
Scattering and re-absorption have been recognized as relevant aspects for the interpretation of solar induced chlorophyll fluorescence (SIF) in vegetation remote sensing. In an earlier study [Yang and Van der Tol, RSE 215, 97–108, 2018] we addressed the problem of scattering and re-absorption of near-infrared fluorescence in the vegetation canopy. In this study we analyse within-leaf re-absorption of both red and near-infrared fluorescence using the radiative transfer model Fluspect. The leaf scattering determines the ratio of backward to total leaf fluorescence emission Fb/(Fb + Ff). Fluspect reproduces this ratio with an RMSE of less than 0.1, and explains the observed dependence of the s…
Constancy and evolution of an engaged writing : the work of Carmen de Burgos, journalist, essayist and novelist
2016
Carmen de Burgos died in 1932, leaving behind a considerable amount of written material: thousands of articles published in different newspapers, essays, novels and hundreds of “novelas cortas”. The works and the memory of this women’s rights activist were doomed to oblivion during Franco’s dictatorship. This thesis aims to rediscover and analyse these works from its various perspectives. We have been looking for the constant trends but also the evolutions. Carmen de Burgos has indeed evolved in her conception of the woman’s role and of the rights she had to acquire. In the early stages of her fight, she had been mainly focusing on the acquisition of equalitarian legal and social rights. Sh…
New super-orthogonal space-time trellis codes using differential M-PSK for noncoherent mobile communication systems with two transmit antennas
2010
Published version of an article in the journal: Annals of Telecommunications-Annales Des Telecommunications. Also available from the publisher at: http://dx.doi.org/10.1007/s12243-010-0191-1 In this paper, we develop super-orthogonal space-time trellis codes (SOSTTCs) using differential binary phase-shift keying, quadriphase-shift keying and eight-phase shift keying for noncoherent communication systems with two transmit antennas without channel state information at the receiver. Based on a differential encoding scheme proposed by Tarokh and Jafarkhani, we propose a new decoding algorithm with reduced decoding complexity. To evaluate the performance of the SOSTTCs by way of computer simulat…
Error mitigation using RaptorQ codes in an experimental indoor free space optical link under the influence of turbulence
2015
In free space optical (FSO) communications, several factors can strongly affect the link quality. Among them, one of the most important impairments that can degrade the FSO link quality and its reliability even under the clear sky conditions consists of optical turbulence. In this work, the authors investigate the generation of both weak and moderate turbulence regimes in an indoor environment to assess the FSO link quality. In particular, they show that, due to the presence of the turbulence, the link experiences both erasure errors and packet losses during transmission, and also compare the experimental statistical distribution of samples with the predicted Gamma Gamma model. Furthermore,…
An asynchronous covert channel using spam
2012
AbstractCurrent Internet e-mail facilities are built onto the foundation of standard rules and protocols, which usually allow a considerable amount of “freedom” to their designers. Each of these standards has been defined based on a number of vendor specific implementations, in order to provide common inter-working procedures for cross-vendor communication. Thus, a lot of optional and redundant information is being exchanged during e-mail sessions, which is available to implement versatile covert channel mechanisms.This work exploits this possibility by presenting a simple but effective steganographic scheme that can be used to deploy robust secret communication through spam e-mails. This s…
Corporate ethical codes as strategic documents: An analysis of success and failure
2009
Ethical codes state the major philosophical principles and values in organizations and function as policy documents which define the responsibilities of organizations to stakeholders. They spell out the conduct expected of employees and articulate the acceptable ethical parameters of behavior in the organization. Most large US and multinational firms today have a code. If utilized effectively and embraced, codes can be key strategic documents in organizations for moderating employee behavior and reducing unethical actions. To be effective they must be communicated well and become a part of the culture of the organization. An ethical code from a major investment bank is analyzed in terms of …
Angular variations of brightness surface temperatures derived from dual-view measurements of the Advanced Along-Track Scanning Radiometer using a new…
2019
Abstract Surface temperatures derived from remote sensing data over heterogeneous, non-isothermal land surfaces depend on the viewing and solar angles mainly due to variations in sunlit and shaded fractions of the different elements in the field of view. The near-simultaneous dual-view capability of the Advanced Along-Track Scanning Radiometer (AATSR) can be used to estimate differences in brightness surface temperatures (BSTs) between the nadir (satellite zenith angle of 0°–21.7°) and forward views (53°–55.6°) in the 11 and 12 μm bands. BST is defined as the black-body temperature corresponding to the radiance at surface level (that is, corrected for atmospheric absorption and emission). W…
On the weight distribution of perfect binary codes
2021
In this paper, we give a new proof of the closed-form formula for the weight distribution of a perfect binary single-error-correcting code.